Genetic ancestry and radical prostatectomy findings in Hispanic/Latino patients

Background

African ancestry is a known factor associated with the presentation and aggressiveness of prostate cancer (PC). Hispanic/Latino populations exhibit varying degrees of genetic admixture across Latin American countries, leading to diverse levels of African ancestry. However, it remains unclear whether genetic ancestry plays a role in the aggressiveness of PC in Hispanic/Latino patients. We explored the associations between genetic ancestry and the clinicopathological data in Hispanic/Latino PC patients from Colombia.

Patients and methods

We estimated the European, Indigenous and African genetic ancestry, of 230 Colombian patients with localized/regionally advanced PC through a validated panel for genotypification of 106 Ancestry Informative Markers. We examined the associations of the genetic ancestry components with the Gleason Grade Groups (GG) and the clinicopathological characteristics.

Results

No association was observed between the genetic ancestry with the biochemical recurrence or Gleason GG; however, in a two groups comparison, there were statistically significant differences between GG3 and GG4/GG5 for European ancestry, with a higher mean ancestry proportion in GG4/GG5. A lower risk of being diagnosed at an advanced age was observed for patients with high African ancestry than those with low African ancestry patients (OR: 0.96, CI: 0.92-0.99, p=0.03).

Conclusion

Our findings revealed an increased risk of presentation of PC at an earlier age in patients with higher African ancestry compared to patients with lower African ancestry in our Hispanic/Latino patients.

Maternal Western diet programs cardiometabolic dysfunction and hypothalamic inflammation via epigenetic mechanisms predominantly in the male offspring

OBJECTIVE

Maternal exposure during pregnancy is a strong determinant of offspring health outcomes. Such exposure induces changes in the offspring epigenome resulting in gene expression and functional changes. In this study, we investigated the effect of maternal Western hypercaloric diet (HCD) programming during the perinatal period on neuronal plasticity and cardiometabolic health in adult offspring.

METHODS

C57BL/6J dams were fed HCD for 1 month prior to mating with regular diet (RD) sires and kept on the same diet throughout pregnancy and lactation. At weaning, offspring were maintained on either HCD or RD for 3 months resulting in 4 treatment groups that underwent cardiometabolic assessments. DNA and RNA were extracted from the hypothalamus to perform whole genome methylation, mRNA, and miRNA sequencing followed by bioinformatic analyses.

RESULTS

Maternal programming resulted in male-specific hypertension and hyperglycemia, with both males and females showing increased sympathetic tone to the vasculature. Surprisingly, programmed male offspring fed HCD in adulthood exhibited lower glucose levels, less insulin resistance, and leptin levels compared to non-programmed HCD-fed male mice. Hypothalamic genes involved in inflammation and type 2 diabetes were targeted by differentially expressed miRNA, while genes involved in glial and astrocytic differentiation were differentially methylated in programmed male offspring. These data were supported by our findings of astrogliosis, microgliosis and increased microglial activation in programmed males in the paraventricular nucleus (PVN). Programming induced a protective effect in male mice fed HCD in adulthood, resulting in lower protein levels of hypothalamic TGFβ2, NF-κB2, NF-κBp65, Ser-pIRS1, and GLP1R compared to non-programmed HCD-fed males. Although TGFβ2 was upregulated in male mice exposed to HCD pre- or post-natally, only blockade of the brain TGFβ receptor in RD-HCD mice improved glucose tolerance and a trend to weight loss.

CONCLUSIONS

Our study shows that maternal HCD programs neuronal plasticity in the offspring and results in male-specific hypertension and hyperglycemia associated with hypothalamic inflammation in mechanisms and pathways distinct from post-natal HCD exposure. Together, our data unmask a compensatory role of HCD programming, likely via priming of metabolic pathways to handle excess nutrients in a more efficient way.

miRNAs signature as potential biomarkers for cervical precancerous lesions in human papillomavirus positive women

Biomarkers to identify women at risk of cervical cancer among those with high-risk HPV infection (hrHPV+) are needed. Deregulated expression of microRNAs (miRNAs) contributes to hrHPV-induced cervical carcinogenesis. We aimed at identifying miRNAs with the capacity to distinguish high (CIN2+) and low (≤ CIN1) grade cervical lesions. We sequenced miRNA libraries from Formalin-Fixed Paraffin-Embedded (FFPE) tissues from women with CIN2+ (n = 10) and age-matched women with ≤ CIN1 (n = 10), randomly and retrospectively selected from a trial that followed women for 24 months after a hrHPV+ test at the screening visit. Five miRNAs differentially expressed were validated by RT-qPCR in an independent set of FFPE tissues with a reviewed diagnosis of CIN2+ (n = 105) and ≤ CIN1 (n = 105). The Ingenuity Pathway Analysis (IPA) was conducted to identify mRNAs inversely correlated with the top 25 differentially expressed miRNAs. Inverse correlations with 401 unique mRNA targets were identified for fourteen of the top 25 differentially expressed miRNAs. Eleven of these miRNAs targeted 26 proteins of pathways deregulated by HPV E6 and E7 oncoproteins and two of them, miR-143-5p and miR-29a-3p, predicted CIN2+ and CIN3+ in the independent validation by RT-qPCR of FFPE tissues from hrHPV-positive women.

Abstract P6-01-40: Integrative transcriptomic analysis and cohort validation identify key genes in chemotherapy treatment response in Latino breast cancer patients

Purpose: Breast cancer (BC) is one of the most frequent invasive cancers and one of the main causes of cancer mortality in women. Effective treatment interventions for BC are urgently required to improve survival rate and quality of life. Chemotherapy has been widely applied in BC treatment; however, therapeutic resistance remains an unresolved issue. Currently, only a minority of patients benefit from chemotherapy, emphasizing the need to identify more effective hub genes associated with therapy response. The overarching goal of this study is to assess hub genes correlated with BC chemotherapy treatment response via multiple databases and validate the workflow in an independent cohort of Hispanic/Latino (Colombian) women diagnosed with invasive Luminal B BC candidates for neoadjuvant chemotherapy. Design: Screening and multistep filtering of common genes correlated with chemotherapeutic response was performed by integrating differentially expressed genes between responders and non-responders in publicly available datasets. For each database, the differentially expressed genes (DEGs) between non-responders and responders were identified using GEO2R and LIMMA. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted for the identified common genes using Metascape and DAVID. Functional enrichment analysis and protein-protein interaction (PPI) network for DEGs were constructed using (STRING) database. Hub genes were identified from PPI network by Cytoscape software analysis. The mRNA expression of hub genes in BC and normal tissues was subsequently explored by UALCAN. Evaluation of the effect of hub genes on survival was performed using Kaplan-Meier plotter. Hub genes were imported into the DGIdb to obtain the potential for BC chemotherapy-associated treatment drugs. The previous workflow was then applied/validated to an Illumina high-throughput RNA sequencing of 50 Luminal B cases (HER2+ and HER2-) of Hispanic/Latino patients. Results: 490 DEGs were obtained from the intersection of five public databases. Pathway enrichment analysis revealed DEGs were associated with cell cycle, estrogen response, adaptive immune response, and regulation of kinase activity, among others. Thirty-two hub genes were identified from PPI network analysis with high degree nodes and betweennesscentrality. Significant differential expression of hub genes between BC tissue and normal tissues was observed in UALCAN. These genes were significantly associated with survival probability. Fifteen potential targeted therapeutic drugs were identified through DGIdb database. Validation workflow in independent Luminal B cohort showed 238 DEGs, 90 hub genes with high degree and enrichment in the regulation of hormone levels, cellular response to EGFR, signaling by ERBB2 and MAPK. GATA3 was the hub gene found in both databases and the validation set. Both databases and validation set show hub genes, enriched pathways, and drugs that indicate their close association with tumorigenesis and would contribute to acting an important role in therapy response prediction. Conclusions: This workflow was created using public databases and applied to a patient’s cohort of different ancestries. This methodology can successfully provide potential biomarkers that correlate with therapy response. Genes were selected from PPI network. Most of them were independent biomarkers of BC treatment response, including that in underrepresented patients. Moreover, these genes may exert critical function in non-response and progression.

Citation Format: Hedda Michelle Guevara-Nieto, Rafael Parra-Medina, Juan C. Mejia-Henao, Patricia López-Correa, Sandra Diaz, Jone Garai, Jovanny Zabaleta, Liliana López-Kleine, Alba L. Combita. Integrative transcriptomic analysis and cohort validation identify key genes in chemotherapy treatment response in Latino breast cancer patients [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-01-40.

Metabolic pathways enriched according to ERG status are associated with biochemical recurrence in Hispanic/Latino patients with prostate cancer

BACKGROUND

The role of ERG-status molecular subtyping in prognosis of prostate cancer (PCa) is still under debate. In this study, we identified differentially expressed genes (DEGs) according to ERG-status to explore their enriched pathways and implications in prognosis in Hispanic/Latino PCa patients.

METHODS

RNA from 78 Hispanic PCa tissues from radical prostatectomies (RP) were used for RNA-sequencing. ERG_high /ERG_low tumor groups were determined based on the 1.5-fold change median expression in non-tumor samples. DEGs with a False Discovery Rate (FDR) < 0.01 and a fold change >2 were identified between ERG_high and ERG_low tumors and submitted to enrichment analysis in MetaCore. Survival and association analyses were performed to evaluate biochemical recurrence (BCR)-free survival.

RESULTS

The identification of 150 DEGs between ERG_high and ERG_low tumors revealed clustering of most of the non-BCR cases (60%) into de ERG_high group and most of the BCR cases (60.8%) in ERG_low group. Kaplan-Meier survival curves showed a worst BCR-free survival for ERG_low patients, and a significant reduced risk of BCR was observed for ERG_high cases (OR = 0.29 (95%CI, 0.10-0.8)). Enrichment pathway analysis identified metabolic-related pathways, such as the renin-angiotensin system and angiotensin maturation system, the linoleic acid metabolism, and polyamines metabolism in these ERG groups.

CONCLUSIONS

ERG_low tumor cases were associated with poor BCR-free survival in our Hispanic/Latino patients, with metabolism-related pathways altered in the BCR progression.

IMPACT

Our findings suggest the need to dissect the role of diet, metabolism, and lifestyle as risk factors for more aggressive PCa subtypes.

IL-1β enhances cell viability and decreases 5-FU sensitivity in novel colon cancer cell lines derived from African American patients

Background

In the U.S., African Americans (AAs) present with the highest incidence and mortality rates for Colorectal Cancer (CRC). When compared to Caucasian American (CA) patients, AAs also have reduced response to the first line standard of care chemotherapeutic agent 5-Fluorouracil (5-FU). Previously, we observed differential gene expression between the two populations, suggesting that colon tumors from AA patients display a decreased antitumor immune response and an increased expression of genes encoding proteins involved in inflammatory processes, such as Interleukin-1β (IL-1β). Here, we investigate the role of IL-1β in modifying chemotherapeutic response and altering expression of proteins in novel AA and well-established CA colon cancer cell lines.

Methods

RNA sequencing analysis was performed to detect expression of genes involved in inflammation in AA and CA colon cancer cells. The effects of IL-1β on 5-FU response was evaluated by assessing cell viability (MTS assay) and apoptosis (flow cytometry analysis) following treatment with 5-FU alone or in combination with the cytokine. Further, we used an IL-1 receptor antagonist (IL-1Ra) to inhibit IL-1β-induced effects on 5-FU sensitivity and NF-kB pathway activation.

Results

AA colon cancer cell lines present significant increase in expression of genes IL1R2 (373-fold change (FC), IRAK1 (3.24 FC), IKBKB, (5.33 FC) NF-KB IA (5.95 FC), MYD88, (3.72 FC), IRAK3 (161 FC), TRAF5 (4.1 FC). A significant decrease in the response to 5-FU treatment, as well as a significant increase in phosphorylation of IκBα and secretion of IL-8, was seen following IL-1β treatment, in both AA and CA cell lines. Finally, treatment with IL-1Ra was able to reverse the effects induced by IL-1β, by increasing the cells sensitivity to 5-FU. IL-1Ra also inhibited phosphorylation of IκBα and IL-8 secretion.

Conclusions

Our results suggest a differential expression of inflammatory genes and proteins that might regulate the different response to IL-1β between AA and CA colon cancer cell lines. Our data also demonstrates that IL-1β is involved in modulating 5-FU response in both AA and CA colon cancer cell lines. Further investigation of these mechanisms might help elucidate the differences seen in incidence, mortality and response to therapy in AA colon cancer patients.

New Insights into Avian Infectious Bronchitis Virus in Colombia from Whole-Genome Analysis

Infectious Bronchitis (IB) is a respiratory disease caused by a highly variable Gammacoronavirus, which generates a negative impact on poultry health worldwide. GI-11 and GI-16 lineages have been identified in South America based on Infectious Bronchitis virus (IBV) partial S1 sequences. However, full genome sequence information is limited. In this study we report, for the first time, the whole-genome sequence of IBV from Colombia. Seven IBV isolates obtained during 2012 and 2013 from farms with respiratory disease compatible with IB were selected and the complete genome sequence was obtained by NGS. According to S1 sequence phylogenetic analysis, six isolates belong to lineage GI-1 and one to lineage GVI-1. When whole genome was analyzed, five isolates were related to the vaccine strain Ma5 2016 and two showed mosaic genomes. Results from complete S1 sequence analysis provides further support for the hypothesis that GVI-1, considered a geographically confined lineage in Asia, could have originated in Colombia. Complete genome information reported in this research allow a deeper understanding of the phylogenetic evolution of variants and the recombination events between strains that are circulating worldwide, contributing to the knowledge of coronavirus in Latin America and the world.

Abstract 1497: miRNA expression analysis in high-risk HPV-positive cervical scrapes for the detection of cervical disease

Cervical cancer is the fourth most frequently diagnosed cancer and the fourth leading cause of cancer death in women, with an estimated 604,000 new cases and 342,000 deaths worldwide in 2020. Persistent infections with high-risk HPV (hrHPV) genotypes can lead to high-grade lesions (Cervical Intraepithelial Neoplasia Grade 2 or higher, CIN2+), that if left untreated progress to cancer. hrHPV test has high sensitivity to detect CIN2+, but it has low specificity because close to 90% of women spontaneously clear the infection. Biomarkers to stratify hrHPV+ women with cervical lesions that may progress to cancer are needed. miRNAs are small noncoding RNAs that regulate gene expression, can be detected in cervical scrapes, and are differentially expressed between high- and low-grade lesions.

Aim To identify miRNAs differentially expressed between CIN3+ and ≤CIN1 lesions and evaluate their potential use as biomarkers to distinguish CIN3+ in hrHPV+ women.

Methods We used miRNAseq to compare miRNAs expression patterns in cervical scrapes of hrHPV+ women: 35 with low-grade lesions (NEG= 26; CIN1= 9) and 36 with high-grade lesions (CIN3= 32; SCC= 4). The samples were collected through the ASCUS-COL Trial in Medellin, Colombia. Women with low- or high-grade cervical lesions exhibit similar sociodemographic characteristics (Chi-square p-values&gt;0.05). The RNAseq data were processed in GeneGlobe-QIAGEN, which incorporates cut-adapt, bowtie and DeSEq2. Receiver Operating Characteristic (ROC) analyses with a 95% confidence interval of Area Under the Curve (AUC) were made to evaluate the diagnostic accuracy of each miRNA differentially expressed, to detect CIN3+. Multivariate Logistic Regression Analysis using normalized counts of mapped reads identified a combination of the differentially expressed miRNAs that best predicted CIN3+. We identified putative pathways using MetaCore.

Results An average of &gt;9 million reads by sample and around 3.5 million reads mapped to miRBase V21 was obtained. The principal component analysis did not show factors that could introduce bias to differential gene expression analysis. We identified 38 miRNAs differentially expressed. Compared to &lt;CIN1 lesions, 9 miRNAs were overexpressed and 29 underexpressed in CIN3+ lesions. Six miRNAs presented AUC&gt;0.60 (p-value &lt;0.05) to detect CIN3+. The best predictive combination of 9 miRNAs exhibits an AUC of 0.89, 95% CI (0.83 - 0.97), of which 4 were overexpressed and 5 underexpressed in CIN3+ vs &lt;CIN1. Interestingly, 5 miRNAs underexpressed in CIN3+, target VEGF, a known angiogenic mediator linked to malignancy.

Conclusion We identified miRNAs differentially expressed with good diagnostic performance to distinguish high- from low-grade lesions in cervical scrapes samples. Further validation on a larger cohort of cervical scrapes samples is needed to confirm the potential role of these miRNAs to triage hrHPV+ women.

Citation Format: Martha Isabel González Ramírez, Samuel Agudelo, Maria Cecilia Agudelo, Jone Garai, Li Li, Carlos Alberto Orozco Castaño, Jovanny Zabaleta, Gloria Inés Sánchez Vásquez. miRNA expression analysis in high-risk HPV-positive cervical scrapes for the detection of cervical disease [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1497.

Abstract 100: IL-1β pathway promotes cell proliferation and 5-FU resistance in African American colon cancer cell lines

Introduction: Colorectal Cancer (CRC) is the third most common cancer and third cause of cancer-related death in the US. When taking race and ethnicity into consideration, African Americans (AA) present with the highest incidence and mortality rates for CRC. Studies have found that AA patients, when compared to Caucasian American (CA) patients, have a lower response to the standard of care chemotherapeutic agent 5-Fluorouracil (5-FU) as well as lower frequency of MSI tumors, making them also less likely to respond to conventional immunotherapies. Our recent findings have shown that tumors from AA patients present higher expression of genes involved in pro-inflammatory processes as well as lower expression of genes promoting anti-tumoral activities. One of the genes that was found upregulated in AA tumors is IL1B, which encodes for the pro-inflammatory cytokine Interleukin-1β (IL-1β). Therefore, we investigated the role of the IL-1β pathway in novel AA colon cancer cell lines. Here, we evaluated changes in cell proliferation, apoptosis, 5-FU response, and activation of inflammatory pathways.

Methods: Our approach includes analysis of gene expression in both AA and CA colon cancer cell lines by using RNA sequencing to evaluate pro-inflammatory genes differentially expressed among the cell lines. Furthermore, we used an MTS assay to detect viable cells following treatment with IL-1β, alone or in combination with different concentrations of 5-FU, as well as analyzing changes in apoptosis via Flow Cytometry. To better understand the mechanisms of IL-1β-induced effects, we used IL-1 Receptor Antagonist (IL-1Ra) to block the IL-1β pathway and evaluated changes in cell viability and 5-FU response via MTS assay, as well as activation of NF-kB pathway, via detection of phospho-IкB-α protein using Western Blot analysis.

Results: Results from MTS assays indicated that cell proliferation in response to IL-1β differs between the AA and the CA colon cancer cell lines, with the AA colon cancer cells being more sensitive to lower concentrations of the cytokine when compared to CA cell lines. Further, we saw an increased expression of phospho-IкB-α following treatment with IL-1β. This expression was reduced when the cells were treated in combination with IL-1β and the IL-1Ra. The IL-1Ra also appears to reduce the pro-proliferative effects induced by IL-1β. Importantly, our results show that 5-FU sensitivity is drastically reduced in the presence of IL-1β for both AA and CA colon cancer cell lines, suggesting that IL-1β may play a role in defining resistance to the chemotherapeutic drug.

Conclusions: Taken together, our results demonstrated a differential response to IL-1β for the AA colon cancer cell lines, suggesting a probable role played by the cytokine in driving inflammation-related cancer progression and reveals a possible new target to exploit in immunotherapy for this population.

Citation Format: Marzia Spagnardi, Jenny Paredes, Jone Garai, Jovanny Zabaleta, Jennie Williams, Laura Martello-Rooney. IL-1β pathway promotes cell proliferation and 5-FU resistance in African American colon cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 100.

Abstract 2121: Gene expression and functional characterization of obesity-induced MDSC to uncover the link between obesity and cancer risk

Strong epidemiologic evidence suggests that excess body weight gain is a major risk of at least 13 different types of cancers. One of the mechanisms explaining the increased cancer incidence in obese patients is associated with the chronic low-grade inflammatory condition. Myeloid cells including macrophages and Myeloid-derived suppressor cells (MDSC) are increased in advanced adiposity. Previous studies in mouse models have shown that obesity-induced MDSC play a protective role on metabolic control; however, in the presence of malignant cells, MDSC facilitates tumor growth and metastasis. Our data show that compared to non-obese individuals, patients with severe obesity (body mass index [BMI] &gt; 40) have a significant increase of circulating granulocytic cells displaying a gene signature resembling tumor-MDSC. Intriguingly, obesity-induced MDSC lacked the potent immunosuppressive function; and therefore, we called them obesity-induced G-MDSC-like cells (Ob-MDSC). The mechanisms underlying the regulation of MDSC phenotype in obesity and obesity-related cancer are unclear. We found that LDL, one altered obesity-related factor, and LPS differentially impact the expression of several genes including the immunosuppressive MDSC markers, arginase-1 and iNOS, when comparing mouse bone marrow-derived MDSC from high-fat fed mice with low-fat fed mice. This finding indicates that the responsiveness of MDSC may be regulated by their long-lasting exposure to the obese microenvironment. Therefore, we propose that long-term adaptation of MDSC is induced by dysfunctional metabolic factors in obesity that modulate their response to subsequent triggers, such as signals derived by the tumor microenvironment (TMA) in the context of obesity-associated cancer. Our data from obese mice with Diethylnitrosamine (DEN)-induced hepatocellular carcinoma and genetically altered hepatic lipid and lipoprotein metabolism show an increased infiltration of G-MDSC associated with enhanced tissue chemokine signaling pathway, ECM remodeling/metastasis, inflammation, and epigenetic and transcriptional regulation. Together our data suggest that chronic exposure to an obesity-related environment establishes a phenotype prone to become pro-tumor MDSC. The identification of key regulators of the gene expression driving the immunosuppressive phenotype of MDSC in obesity is critical for the discovery of therapeutical targets to reduce the risk of obesity-associated cancers.

Citation Format: Maria D. Sanchez-Pino, Ramesh Thylur Puttalingaiah, Jone Garai, Jovanny Zabaleta, Randall L. Mynatt, William Richardson, Augusto Ochoa. Gene expression and functional characterization of obesity-induced MDSC to uncover the link between obesity and cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2121.

Abstract 1255: Identification of predictive biomarkers for neoadjuvant chemotherapy response in invasive breast cancer Latino patients

Purpose: Breast cancer (BC) is the leading cause of morbidity and mortality in women in Colombia, constituting a major public health issue. Importantly, not all breast cancer patients respond to neoadjuvant chemotherapy (NAC), leading to an incomplete pathological response and suggesting that there are tumor characteristics that may explain the differences in response. The overarching goal of this study is to identify gene expression profiles associated with an incomplete pathological response to NAC in Colombian women with invasive BC.

Design: An integrative transcriptome analysis using Illumina high-throughput RNA sequencing was performed from 63 baseline and post-NAC (follow-up) paraffin-embedded samples from 46 different female patients with locally advanced BC (stage IIB to IIIC) treated at the Colombian National Cancer Institute. Gene expression data were obtained from 42 baseline and 21 follow-up samples. Two comparison analyses were conducted to identify differentially expressed genes (DEGs) first comparing baseline vs follow-up samples from nonresponders to NAC and second comparing to baseline samples from nonresponders vs responders to NAC. Additionally, enrichment analyses were performed in both comparative analyses.

Results: From 46 patients included, 20 had a pathological complete response (pCR), while 26 did not show pCR. By investigating the gene expression profiling, 1546 significantly DEGs and 174 DEGs were identified among non-responders and Baseline analyses, respectively. From these analyses, 24 DEGs were found in common and apoptosis as the only shared enrichment pathway (p=0.001). In both analyses, Histone associated genes were downregulated in nonresponders (Histone 3, p=0,001 and Histone 2B, p&lt;0,001). In addition, downregulation of Granzyme B and perforin were also found differentially expressed in apoptosis network pathways. CD8+ naïve T-cells, hematopoietic stem cells, Macrophages, Macrophages M1, Neurons, Th1 cells, activated dendritic cells and pro B cells were defined by the xCell algorithm and showed statistically significant association with non-response to NAC.

Conclusions: Changes in histones and tumor microenvironment cell populations elicits local immune response, which contributed to therapeutic efficacy. Downregulation of Granzyme B and perforin could block mechanism of resistance to carcinogenesis, leading to non-response to NAC. Furthermore, patients with tumors containing higher gene signatures of these DEGs may benefit from NAC. Additional validations are needed to confirm these data. If confirmed, these data may be relevant in elucidating the mechanisms that lead to therapy resistance as well as in selecting patients that will benefit from NAC in Latino (Colombian) patients.

Citation Format: Hedda Michelle Guevara-Nieto, Rafael Parra-Medina, Juan Carlos Mejia-Henao, Patricia Eugenia López-Correa, José Ismael Guío-Avila, Sandra Diaz-Casas, Jone Garai, Jovanny Zabaleta, Liliana López-Kleine, Alba Lucia Cómbita. Identification of predictive biomarkers for neoadjuvant chemotherapy response in invasive breast cancer Latino patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1255.

Increased inflammatory low-density neutrophils in severe obesity and effect of bariatric surgery: Results from case-control and prospective cohort studies

BACKGROUND

Low-density neutrophils (LDN) are increased in several inflammatory diseases and may also play a role in the low-grade chronic inflammation associated with obesity. Here we explored their role in obesity, determined their gene signatures, and assessed the effect of bariatric surgery.

METHODS

We compared the number, function, and gene expression profiles of circulating LDN in morbidly obese patients (MOP, n=27; body mass index (BMI) > 40 Kg/m²) and normal-weight controls (NWC, n=20; BMI < 25 Kg/m²) in a case-control study. Additionally, in a prospective longitudinal study, we measured changes in the frequency of LDN after bariatric surgery (n=36) and tested for associations with metabolic and inflammatory parameters.

FINDINGS

LDN and inflammatory markers were significantly increased in MOP compared to NWC. Transcriptome analysis showed increased neutrophil-related gene expression signatures associated with inflammation, neutrophil activation, and immunosuppressive function. However, LDN did not suppress T cells proliferation and produced low levels of reactive oxygen species (ROS). Circulating LDN in MOP significantly decreased after bariatric surgery in parallel with BMI, metabolic syndrome, and inflammatory markers.

INTERPRETATION

Obesity increases LDN displaying an inflammatory gene signature. Our results suggest that LDN may represent a neutrophil subset associated with chronic inflammation, a feature of obesity that has been previously associated with the appearance and progression of co-morbidities. Furthermore, bariatric surgery, as an efficient therapy for severe obesity, reduces LDN in circulation and improves several components of the metabolic syndrome supporting its recognized anti-inflammatory and beneficial metabolic effects.

FUNDING

This work was supported in part by grants from the National Institutes of Health (NIH; 5P30GM114732-02, P20CA233374 - A. Ochoa and L. Miele), Pennington Biomedical NORC (P30DK072476 - E. Ravussin & LSU-NO Stanley S. Scott Cancer Center and Louisiana Clinical and Translational Science Center (LACaTS; U54-GM104940 - J. Kirwan).

Abstract PO-227: Role of IL-1β pathway in colon cancer progression and its therapeutic implications in African American colon cancer cell lines

Background: Colorectal cancer (CRC) is the third most common cancer and third cause of cancer-related death among African Americans (AA) in the US. When compared to Caucasian Americans (CA), AA patients present with higher incidence and mortality rates for CRC. Recent findings indicate that they have reduced response to the standard of care chemotherapeutic agent 5-Fluorouracil (5-FU) as well as lower frequency of MSI tumors, making them also less likely to respond to conventional immunotherapies. Previous results from human genomic analyses suggest that certain differences seen in AA patients might be due to a decreased antitumor immune response as well as an increased expression of genes involved in inflammatory processes, such as Interleukin-1β (IL-1β). Therefore, we aimed to investigate the role of IL-1β in promoting cell proliferation, cell migration, 5-FU resistance and activation of specific inflammatory pathways in novel AA colon cancer cell lines, and how these responses would compare to well established CA colon cancer cell lines. Methods: Our approach includes using MTS colorimetric assay and Transwell assay to examine the effects of IL-1β treatment on cell proliferation and migration. We performed Western Blot analysis to detect expression of phosphoproteins following treatment with IL-1β. We also investigated how IL-1β affects 5-FU resistance in AA and CA colon cancer cell lines in terms of cell viability. Finally, we tested the ability of IL-1 Receptor antagonist (IL-1Ra) to inhibit the effects of IL-1β on cell proliferation, protein expression, and 5-FU response. Results: Our MTS assay results indicated that cell proliferation in response to IL-1β differs between the AA and the CA colon cancer cell lines, with the AA colon cancer cells being more responsive. Whereas, the migration rate is increased after stimulation with IL-1β for both AA and CA colon cancer cell lines. Protein expression of Phospho-IkB-alpha is increased in AA but not CA colon cancer cell lines following IL-1β treatment, while Phospho-JNK expression was different between the cell lines following treatment. Importantly, our results show that 5-FU efficacy is decreased in the presence of IL-1β for both AA and CA colon cancer cell lines and that treating the cells with IL-1Ra appeared to reestablish 5-FU cell killing effect. IL-1Ra also suppresses the effects of IL-1β on cell proliferation and protein expression. Conclusions: Taken together, our results demonstrated a differential response to IL-1β for the AA colon cancer cell lines, suggesting a probable role played by the cytokine in driving inflammation-related cancer progression and reveals a possible new target to exploit in immunotherapy for this population.

Citation Format: Marzia Spagnardi, Jenny Paredes, Jone Garai, Jovanny Zabaleta, Jennie Williams, Laura Martello-Rooney. Role of IL-1β pathway in colon cancer progression and its therapeutic implications in African American colon cancer cell lines [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-227.

Severe COVID-19 Is Characterized by an Impaired Type I Interferon Response and Elevated Levels of Arginase Producing Granulocytic Myeloid Derived Suppressor Cells

COVID-19 ranges from asymptomatic in 35% of cases to severe in 20% of patients. Differences in the type and degree of inflammation appear to determine the severity of the disease. Recent reports show an increase in circulating monocytic-myeloid-derived suppressor cells (M-MDSC) in severe COVID 19 that deplete arginine but are not associated with respiratory complications. Our data shows that differences in the type, function and transcriptome of granulocytic-MDSC (G-MDSC) may in part explain the severity COVID-19, in particular the association with pulmonary complications. Large infiltrates by Arginase 1+ G-MDSC (Arg+G-MDSC), expressing NOX-1 and NOX-2 (important for production of reactive oxygen species) were found in the lungs of patients who died from COVID-19 complications. Increased circulating Arg+G-MDSC depleted arginine, which impaired T cell receptor and endothelial cell function. Transcriptomic signatures of G-MDSC from patients with different stages of COVID-19, revealed that asymptomatic patients had increased expression of pathways and genes associated with type I interferon (IFN), while patients with severe COVID-19 had increased expression of genes associated with arginase production, and granulocyte degranulation and function. These results suggest that asymptomatic patients develop a protective type I IFN response, while patients with severe COVID-19 have an increased inflammatory response that depletes arginine, impairs T cell and endothelial cell function, and causes extensive pulmonary damage. Therefore, inhibition of arginase-1 and/or replenishment of arginine may be important in preventing/treating severe COVID-19.

Abstract 2729: Cell infiltration prediction of breast cancer tissues identifies basophils as potentially important immune cells in the tumor microenvironment

Background: Breast cancer (BC) is the most common and deadliest cancer in women worldwide. Hormone receptor (HR) positive tumors (luminal) are the most frequent while HER-2 overexpressing (HR-, HER2+) and triple negative (TNBC, HR-/HER2-) are most deadly. HR+ subtypes are more common in non-Hispanic White women while HER-2 and TNBC present either higher prevalence or risk of mortality in minority groups. Hispanic/Latinos (H/L) is the largest and fastest growing minority in the U.S.A. However, H/L women have been underrepresented in BC studies. We reported that luminal B is the most common BC subtype in a group of H/L and that ERBB2, GRB7 and MIEN1 genes have increased expression in women with higher Indigenous American ancestry. Immune infiltration of tumors has become a hallmark for the prediction of outcome. However, contrary to TNBC, luminal tumors have been considered low immunogenic. Immune infiltration of luminal B tumors in H/L has not yet been investigated. Our goal was to predict immune infiltration of luminal B tumors based on RNA-seq data and according to the levels of body mass index (BMI) and ancestral fractions (West African, European, Indigenous American).

Methods: We performed RNA-seq in 70 luminal B tumors of H/L from Puerto Rico. Ancestry was estimated by genotyping on the Affymetrix U.K. Biobank array and global ancestry proportions determined with Admixture Software v1.3, using 1000 Genomes reference population for anchoring. BMI, age at diagnosis and tumor size were extracted from the Electronic Medical Records. We used Partek Flow for the RNA-seq analysis based on ancestry fraction and BMI. Prediction of cell populations was done in xCell. Correlation analysis was done in GraphPad Prism v7.05.

Results: We found an inverse correlation between Indigenous American and γδ-T cell infiltration (R2= -0.3; p=0.03) while BMI was associated with increased infiltration of basophils (R2=0.3; p=0.026). Among women with high BMI, those with low European ancestry had increased levels of basophils infiltration R2=0.66; p=0.17) and those with high European ancestry had reduced infiltration of naïve CD8+ T cells (R2= -0.53; p=0.008) and reduced plasmacytoid dendritic cells (pDC, R2=-0.51; p=0.01).

Conclusions: We found that luminal B tumors have infiltration of immune cells that may contribute to differences in the response to treatment and outcome. To the best of our knowledge, the role of infiltrating basophils into breast cancer tissues has not been described. However, circulating basophils and predicted infiltration of basophils into ovarian and colorectal cancer tissues have been correlated with survival. Our findings have to be confirmed in a larger set of samples and by additional methods, including immunohistochemistry.

Citation Format: Jone Garai, Julie Dutil, Douglas W. Cress, Victoria Seewaldt, Jamie K. Teer, Laura Fejerman, Lucio Miele, Jovanny Zabaleta. Cell infiltration prediction of breast cancer tissues identifies basophils as potentially important immune cells in the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2729.

Transcriptome and Functions of Granulocytic Myeloid-Derived Suppressor Cells Determine their Association with Disease Severity of COVID-19

COVID-19 ranges from asymptomatic in 35% of cases to severe in 20% of patients. Differences in the type and degree of inflammation appear to determine the severity of the disease. Recent reports show an increase in circulating monocytic-myeloid-derived suppressor cells (M-MDSC) in severe COVID 19, that deplete arginine but are not associated with respiratory complications. Our data shows that differences in the type, function and transcriptome of Granulocytic-MDSC (G-MDSC) may in part explain the severity COVID-19, in particular the association with pulmonary complications. Large infiltrates by Arginase 1 ⁺ G-MDSC (Arg ⁺ G-MDSC), expressing NOX-1 and NOX-2 (important for production of reactive oxygen species) were found in the lungs of patients who died from COVID-19 complications. Increased circulating Arg ⁺ G-MDSC depleted arginine, which impaired T cell receptor and endothelial cell function. Transcriptomic signatures of G-MDSC from patients with different stages of COVID-19, revealed that asymptomatic patients had increased expression of pathways and genes associated with type I interferon (IFN), while patients with severe COVID-19 had increased expression of genes associated with arginase production, and granulocyte degranulation and function. These results suggest that asymptomatic patients develop a protective type I IFN response, while patients with severe COVID-19 have an increased inflammatory response that depletes arginine, impairs T cell and endothelial cell function, and causes extensive pulmonary damage. Therefore, inhibition of arginase-1 and/or replenishment of arginine may be important in preventing/treating severe COVID-19.

Molecular detection of opportunistic pathogens and insights into microbial diversity in private well water and premise plumbing

Private well water systems in rural areas that are improperly maintained will result in poor drinking water quality, loss of water supply, and pose human health risk. The purpose of this study was to investigate the occurrence of fecal indicator bacteria (FIB) and opportunistic pathogens in private well water in rural areas surrounding New Orleans, Louisiana. Our results confirmed the ubiquitous nature of Legionella (86.7%) and mycobacteria (68.1%) in private well water in the study area, with gene concentration ranged from 0.60 to 5.53 and 0.67 to 5.95 Log₁₀ of GC/100 mL, respectively. Naegleria fowleri target sequence was detected in 16.8% and Escherichia coli was detected in 43.4% of the water samples. Total coliform, as well as Legionella and mycobacteria genetic markers' concentrations were significantly reduced by 3-minute flushing. Next-generation sequencing (NGS) data indicated that the abundance of bacterial species was significantly increased in water collected in kitchens compared with samples from wells directly. This study provided integrated knowledge on the persistence of pathogenic organisms in private well water. Further study is needed to explore the presence of clinical species of those opportunistic pathogens in private well water systems to elucidate the health risk.

Immune-Related Gene Expression and Cytokine Secretion Is Reduced Among African American Colon Cancer Patients

Background: Colorectal cancer is the third most deadly cancer among African Americans (AA). When compared to Caucasian Americans (CA), AA present with more advanced disease and lower survival rates. Here, we investigated if differences in tumor immunology could be contributive to disparities observed between these populations.

Methods: We examined gene expression of tumor and non-tumor adjacent tissues from AA and CA by whole transcriptome sequencing, and generated scores for immune cell populations by NanoString. In addition, we utilized “The Cancer Genome Atlas” (TCGA) database from AA and CA as a validation cohort. Finally, we measured the secretion of cytokines characteristic of effector T helper cell (T_h) subsets by ELISA using plasma from each AA and CA participant.

Results: Colon tumors from AA patients showed significant fold-change increase in gene expression when compared to CA for FOXP3 (6.22 vs. 3.22), IL1B (103 vs. 11.4) and IL8 (220 vs. 28.9) (p < 0.05). In contrast, among CA we observed statistically higher gene expression of markers associated with antitumor activity such as GZMB (Granzyme B), IFNG and the immunotherapy targets PDL1 (CD274) and CTLA4 (p < 0.05). TCGA data validated our observed higher gene expression of GZMB and PDL1 in CA patients when compared to AA. Notably, our observations on immune cell populations show that AA tumors have significantly higher number of exhausted CD8+ cells (p < 0.01), mast cells (p < 0.02) and increased T regulatory cells when compared to CA. AA colon cancer patients differed from CA in cytokine production patterns in plasma (i.e., reduced IL-12).

Conclusions: Our study demonstrates significant differences of the immunological profiles of colon tumors from AA compared to CA that suggest a deficiency of appropriate immune defense mechanisms in terms of gene expression, recruitment of immune cells and systemic secretion of cytokines. As such, these immune differences could be mitigated through population-specific therapeutic approaches.

Abstract 267: microRNA expression analysis in hrHPV positive FFPE tissues for the detection of cervical disease

Cervical cancer ranks first in cancer mortality among women of low-middle income countries where 80% of the 570,000 cases and 311,000 worldwide deaths estimated for 2018 occurred. Persistent infections with high-risk HPV (hrHPV) genotypes can lead to cervical high-grade lesions (Cervical Intraepithelial Neoplasia grade 2 or more severe disease, CIN-II+), that if left untreated progress to cancer. hrHPV test has high sensitivity but because many women infected with hrHPV genotypes will clear the infection spontaneously, it has low specificity to detect CIN-II+. MicroRNAs (miRNAs) are small RNAs that regulate gene expression and show differential profiles in cervical intraepithelial lesions. Our aim was to identify miRNAs differentially expressed in CIN-II+ and to evaluate their potential use as biomarkers to distinguish low from high-grade lesions in hrHPV positive women. Methods We compared the miRNAs expression pattern between Formalin-Fixed Paraffin-Embedded (FFPE) tissues from hrHPV positive women with low-grade lesions (n=10) and women with high-grade lesions (n=10) of Medellin, Colombia, using the QIAseq miRNA Library Kit (Qiagen) and sequencing reagents and protocols from Illumina. The miRNAs with low coefficient of variation and high fold change were further validated by RT-PCR (miR-133a-3p, 143-3p, 143-5p, 29a-3p and 30b-5p) using miRCURY LNA miRNA PCR kit (Qiagen) and SNORD44 as housekeeping gene. Receiver Operating Characteristic (ROC) analyses with 95% confidence interval of the area under the curve were used to evaluate the diagnostic accuracy of the 5 miRNA and their combinations and the maxim Youden index to determine the optimal specificity and sensitivity. Results The differential miRNAs expression analysis identified 25 miRNAs overexpressed in high- versus low-grade lesions. The relative expression by RT-PCR of 5 of those miRNAs was higher in high-grade when compared to low-grade, and the levels of miR-143-3p, 143-5p and 30b-5p increased with disease progression (from healthy, CIN-I, CIN-II, CIN-III+). ROC analyses showed that miR-143-5p and the combination with miR-133a-3p exhibits the highest AUC 79% (95% CI: 65-93). However, the highest sensitivity is given by miR-29a-3p, 87.50% (95% CI: 67.64 - 97.34), and the highest specificity is given by miR-30b-5p, 95.45% (95% CI: 77.16-99-88), with cut-offs of &gt;1,157 and &gt;3,345 respectively. In conclusion, we identified 25 candidate miRNAs biomarkers and validated 5 of them with good diagnostic performance to distinguish high-grade from low-grade cervical lesions. Further validation on a larger cohort of samples is needed to confirm the potential role of these microRNAs to triage HPV positive women.

Citation Format: Martha I. Gonzalez, Jone Garai, Jovanny Zabaleta, Gloria I. Sanchez. microRNA expression analysis in hrHPV positive FFPE tissues for the detection of cervical disease [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 267.

Abstract 3618: Mutational analysis of colon tumors from African American patients and potential association with cancer disparities

Background: Colorectal cancer is the third most deadly cancer among African Americans (AA). When compared to Caucasian Americans (CA), AA present with more advanced disease and lower survival rates. We have previously demonstrated that colon tumors from AA and CA differ in their immune cell recruitment and their systemic cytokines secretion profiles. Therefore, in this study we investigated if differences in gene expression and mutational profiles could relate to the disparities observed between these populations.

Methods: We examined gene expression of colon tumor and non-tumor adjacent tissues from AA (n=20) and CA (n=20) by whole transcriptome sequencing (Illumina); and determined the differential expression of the 170 genes of the Illumina's TruSight Tumor 170 panel (TST170) in AA (n=12) and CA (n=17) colon tumor and non-tumor adjacent tissues.

Results: From our gene expression studies, we found that colon tumors from AA patients showed significant fold-change increases in gene expression when compared to CA for FOXP3 (6.97 vs. 3.15), IL1B (122 vs. 14) and IL8 (262 vs. 28) (p &lt; 0.05). In contrast, among CA we observed statistically higher gene expression of markers associated with antitumor activity such as GZMB (Granzyme B), IFNG and immunotherapy targets PDL1 (CD274) and CTLA4 (p &lt; 0.05). Through our mutational profiling we identified 38 genes in AA and 6 in CA differentially expressed between tumor and non-tumor tissues (p &lt; 0.01). Of those, 5 genes associated with several roles in cancer ETV4 (poor prognosis), CCND1 (tumorigenesis), FGFR2 (activation of the RAS-MAPK and the PI3K-AKT pathways) BRCA2 (genome stability), BCL2 (apoptosis regulator) were commonly altered in both cohorts.

Conclusions: Our study demonstrates significant differences in the genetic characteristics of colon tumors from AA compared to CA that suggest a deficiency of appropriate immune defense features in terms of gene expression. We also observed divergence in the mutational profiling between the groups, including numerous genes that are indicative of prognosis, treatment and outcomes in colon cancer. As such, these deficits could be mitigated through population-specific therapeutic approaches.

Citation Format: Jenny Paredes, Jone Garai, Li Li, Melody Baddoo, Ping Ji, Sayed Imtiaz, Marzia Spagnardi, Mubarak Akadri, Raavi Gupta, Mohamed Alshal, Maksim Agaronov, Henry Talus, Jennie L. Williams, Laura Martello-Rooney, Jovanny Zabaleta. Mutational analysis of colon tumors from African American patients and potential association with cancer disparities [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3618.

Abstract 1409: Identification of microRNA upregulated in pediatric precursor-B cell acute lymphoblastic leukemia patients with post-induction MRD positivity

Background and goal: MicroRNAs (miRNA) are small non-coding RNA that regulate post-transcriptional gene expression, influencing cell proliferation, differentiation and death. Extensive research has demonstrated that deregulation of miRNA-associated pathways may participate in the development of cancers. Precursor-B cell acute lymphoblastic leukemia (pre-B ALL) is the most common pediatric malignancy. Over decades, medical advances have helped the risk stratification and treatment modalities for these patients resulting in better favorable prognosis. Unfortunately, approximately 5-10% of standard risk patients and 15-20% of high or very-high risk patients will experience disease relapse. One of the factors involved in risk stratification is the minimal residual disease (MRD) status from bone marrow testing at the end of the initial induction phase of chemotherapy. MRD positivity escalates the risk and may signify some degree of therapy resistance. The aim of this study is to evaluate expression levels of miRNAs in MRD positive samples as compared to MRD negative.

Methods: Bone marrow samples of 14 pre-B cell ALL pediatric patients with MRD positivity (n=5) and MRD negative (n=9) at the end of induction chemotherapy were analyzed. Next-generation sequencing technology was utilized to study the miRNAs profiles of these samples (smallRNA-seq) and to identify potential mRNA targets of selected miRNAs overexpressed in NALM6 B-ALL cell lines for 72 hours (RNA-seq). Analysis was done in Partek Flow and with the web-based tool InteractiVenn.

Results: Twelve miRNAs were upregulated in patients with MRD positivity compared to those who were MRD negative (p values &lt; 0.05). To investigate the potential role of these mRNAs in pre-B ALL cells, we selected 3 of those miRNAs (hsa-miR-34a-5p, -33b-5p, and -210-3p) to transfect the pre-B-ALL cell line NALM6. We identified 145 potential direct target genes for hsa-miR-33b-5p, 79 potential targets for hsa-miR-34a5-p and 142 potential targets for hsa-miR-210-3p. Thirty-five genes were common among all treatments including IL31A, PDZK1 and INSL3. Individual (per miRNA) pathways associated with these genes included immune response, metabolism and cell signaling. One common pathway associated with the differential expression profile of these overexpressed miRNAs was alcohol intake, known to have deleterious consequences in the fetus and inducing, among other things, transgenerational epigenetic alterations that may be associated with malignancy.

Conclusions: Our work identifies potential biomarkers of MRD positivity after induction chemotherapy and identifies pathways associated with this phenomenon. Future plans include the manipulations of several of these pathways to determine their role in the proliferation and aggressiveness of pre-B ALL leukemia cell with the idea of devising new treatment options for those patients with post-induction MRD positivity.

Citation Format: Andrea Bauchat, Lauren Raney, Jone Garai, Li Li, Randall Craver, Jovanny Zabaleta. Identification of microRNA upregulated in pediatric precursor-B cell acute lymphoblastic leukemia patients with post-induction MRD positivity [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1409.

Abstract IA06: Understanding the molecular landscape of gastric premalignant lesions

Even though the incidence of gastric cancer has been declining over the years, it still has a very high mortality rate. The incidence and mortality of gastric cancer is, however, significantly higher in minority populations with African Americans and Hispanic individuals presenting 52% and 43%, respectively, more cases than Caucasians (data for male patients). Gastric adenocarcinoma has been strongly associated to infection with Helicobacter pylori (H. pylori). The infection triggers an inflammatory cascade, known as the Correa's cascade, that changes the normal gastric epithelium into nonatrophic gastritis (NAG), multifocal atrophic gastritis (MAG), intestinal metaplasia (IM), dysplasia, and cancer. It is known that these events involve immune infiltration and damage to the gastric mucosa; however, there is still too much to learn about the gastric premalignant stages and the evolution of them over time. Over the years we have identified single-nucleotide polymorphisms (SNPs) and differential expression of genes associated with premalignant stages and with evolution of the disease over time. We found that African Americans have increased incidence of advanced premalignant lesions and have more prevalence of infection with H. pylori than Whites. In addition, we found that SNPs and haplotypes in the interleukin 1 b gene (IL1B) are associated with advanced gastritis in African American individuals. Interestingly, the frequency of these inflammatory SNPs and haplotypes is different among African American and Caucasian individuals. In terms of gene expression, we have also found that the increased expression of the gene deleted in malignant brain tumors 1 (DMBT1) is associated with the development of advanced gastritis while the expression of CD44 is associated with progression of the disease over time. Given that CD44 is a molecule involved in the homing of inflammatory cells, its association with progression of premalignant stages over time highlights the role of the immune response in the outcome of these lesions. Interestingly, these immune responses seem to be also modulated by H. pylori itself. We have shown that H. pylori components are able to modulate acquired and innate immune responses. In addition, we have also found a microRNA pattern associated with advanced premalignant gastric lesions in both African Americans and Caucasians. Understanding the molecular landscape of the gastric lesions may help us devise strategies to intervene and limit their progression into more advanced lesions, including gastric cancer.

Citation Format: Jone Garai, Maria B. Piazuelo, Maria C. Camargo, Pelayo Correa, Keith Wilson, Jovanny Zabaleta. Understanding the molecular landscape of gastric premalignant lesions [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr IA06.

Abstract C035: Relationship between ancestry fractions and gene expression in triple-negative breast cancer in Hispanic/Latina women

Background: Breast cancer is the most frequently diagnosed form of invasive cancer in women and the second leading cause of cancer death. Triple-negative breast cancer (TNBC) accounts for 10-20% of the disease. This aggressive subtype lacks receptors for estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2), drastically reducing treatment options. Hispanic/Latinas, who derive ancestry from European, African, and Native origins, are at least 30% more likely to be diagnosed with TNBC compared to non-Hispanic White women. However, little is known about the genomic architecture of TNBCs in Hispanic/Latinas. The goal of our study was to test the association between genetic ancestry and gene expression in TNBC samples from Hispanics/Latinas to help identify potential therapeutic targets.

Methods and Results: We obtained 41 TNBC tissues through collaboration with the National Cancer Institute in Colombia along with demographic and clinical information. Genetic ancestry proportions were estimated using a panel of 106 Ancestry Informative Markers (AIMs). RNA was extracted from FFPE tissues, qualified using Agilent chips, and used for RNA sequencing at the Translational Genomics Core at the Stanley S. Scott Cancer Center. We used an online tool (http://cbc.mc.vanderbilt.edu/tnbc/) to validate TNBC status, and 33 of the 41 samples were confirmed. Quality control procedures ensured that the samples were of acceptable quality for further analysis. Individuals were classified as having high or low genetic ancestry proportions for each of the ancestral components, based on mean ancestry proportions overall. Differential gene expression between individuals in each ancestry category was estimated utilizing DESeq2 in R-Studio. Average genetic ancestry proportions for the 33 samples analyzed were 0.52 European (18 individuals were in the high European ancestry group, 14 in the low European ancestry group), 0.36 Indigenous American (15 high, 17 low) and 0.1 African (8 high, 24 low). We observed that 91 genes were differentially expressed between high vs. low European ancestry, 21 for the Native and 12 for the African. Interestingly, 5 genes were common between the European and Native ancestries. LGALS9C and MESP1 had significant differences in normalized counts between high and low ancestry for both the Europeans and Natives, though the subgroups displayed opposite correlation patterns. These results were validated by real-time PCR. Using cBioPortal, we found that MESP1 and LGALS9C were associated with amplification in 2.8% and 1.5% of breast cancer cases, respectively. LGALS9C expression displays an inverse correlation with disease outcome in several cancers, including breast.

Conclusions: Our data suggest that expression levels of several genes, most notably MESP1 and LGALS9C, may be ancestry specific in TNBC patients from Colombia. Confirmation and further understanding of these findings are of outmost importance given that they could be therapeutic targets.

Citation Format: Laura Carrasquilla, Jone Garai, Silvia J. Serrano-Gomez, Maria C. Sanabria-Salas, Melody C. Baddoo, Laura Fejerman, Jovanny Zabaleta. Relationship between ancestry fractions and gene expression in triple-negative breast cancer in Hispanic/Latina women [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C035.

Abstract C034: Differential gene expression according to ancestry in Hispanic/Latina women with luminal B breast cancer

Background: Breast cancer (BC) is the second leading cause of cancer-related death in women. There is a lack of breast cancer studies showing the differential gene expression in minorities. We have previously found differences in gene expression according to ancestry in Hispanic/Latina women with BC. The goal of our study was to determine the differential gene expression between high and low European, African, and Native ancestries of Hispanic/Latina women with luminal B BC.

Methods: Breast cancer tissue samples were collected from the Moffitt Cancer Center (MCC) in Tampa, FL, and had been analyzed for ancestry informative markers (AIMs) as part of a collaboration between MCC and the University of Puerto Rico. The RNA was quantified, qualified, and used to prepare genomic libraries using regents and protocols from Illumina at the Translational Genomics Core, Stanley S. Scott Cancer Center, LSUHSC-New Orleans. Quality assessment showed close to 50% alignment in coding regions. Raw counts were normalized and used to perform differential gene expression analysis (p&lt;0.05 and fold change &gt;2.0) using DESeq2 in R-Studio between individuals with high and low European, African, and Native ancestral fractions. Heatmaps were used to compare the distribution of the samples visually based on ancestry fraction and the level of gene expression. We used the online tool Venny (http://bioinfogp.cnb.csic.es/tools/venny/) to identify significantly different genes that were uniquely expressed in each ancestral group or shared between them. In addition, we used online tools (http://xcell.ucsf.edu/) for cell infiltration analysis and the software MetaCore to identify possible pathways in which the differentially expressed genes may be involved.

Results: We found a significant inverse correlation between European and both African and Native American ancestries, and these clearly separated based on high and low ancestral fraction. Eighteen genes were shared between European and Native American ancestries, showing opposite expression between the ancestries, suggesting an ethnicity-associated expression. The expression of these genes was validated by real-time PCR. Interestingly, cBioportal analysis showed that ANO1, EPN3, PLAT, and TRPA1 genes are frequently amplified in breast cancer. Furthermore, one gene SPAG6 was commonly expressed among all ancestries with a positive correlation in Native ancestry and negative correlation in European ancestry. We found that African ancestry was associated with the infiltration on lymphocyte progenitors and type 2 macrophages. Meanwhile, European and Native ancestries correlated with type 2 lymphocytes and monocytes, respectively. Pathway analysis revealed possible activation of immune responses driven by genes significant in European and Native ancestries.

Conclusions: Overall, our data suggest that patients with luminal B breast cancer may have differential gene expression associated to ancestry, to gene abnormalities and differential immune responses.

Citation Format: Joussette I. Alvarado, Jone Garai, Li Li, Adam J. Boe, Doug Cress, Teresita Antonia, Jamie Teer, Lucio Miele, Jovanny Zabaleta. Differential gene expression according to ancestry in Hispanic/Latina women with luminal B breast cancer [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C034.

Abstract C118: Tumor immune response in colon cancer African American patients and its role in cancer disparities

Introduction: Colorectal cancer (CRC) is the third most common cancer among African Americans (AA) and when compared to Caucasian Americans (CA), they present more advanced CRC disease and lower survival rates. Our previous findings suggest that this may be related to the differential expression in genes linked to cell recruitment and immune response. Therefore, we aimed to investigate the cellular antitumor activity and mutational profile of colon tumors from AAs. We also examined the secretion of cytokines characteristic of immune responses by different effector T helper cells (Th) subsets in AA and CA patients, as well as cell lines, to see if these differences play a role in the health disparities observed between these populations. Lastly, we observed the expression of the Program Death Ligand 1 (PD-L1) in response to the cytokines IL-17A and TNF-α in a microsatellite-unstable (MSI) AA and a microsatellite-stable (MSS) CA colon cancer cell line.

Methods: Using IHC, we evaluated the cell recruitment and activation of T and natural killer cells in AA tumors. For mutational analysis, we utilized the TruSight Tumor 170 RUO kit (Illumina). ELISA assays (RayBiotech) were used to examine the secretion of cytokines linked to Th subsets (Th1, Th2, Th17) and inflammation in plasma from the AA and CA CRC patients, as well as in supernatants from the AA and CA colon cancer cell lines. Western blots were used to observe the expression of PD-L1 in the in vitro models.

Results: ELISAs of plasma of CA and AA patients revealed a differential Th cytokines production patterns between early-stages (I, II) and late-stage (III) disease. The MSI AA cell line showed an increase on PD-L1 protein expression in response to IL-17A and TNF-α with an additive effect when combined in equal concentrations. Lastly, the mutational sequencing allowed us to further investigate the potential alterations that are responsible for the differences that we observed in gene expression between AAs and CAs in our RNA and cytokine expression profiling.

Conclusions: Our results indicate that the immune profiles of AA patients differ from CA in terms of cytokines' production; AAs expressed elevated IL-17A, whereas CA expressed elevated IFN-γ, the latter indicative of Th1 immunity that has a more favorable prognosis. As such, these differences could be used as biomarkers and to guide therapeutic strategy for these populations. The mutational sequencing will help us to elucidate the impaired tumor immune response in AAs with colon cancer when compared to CAs that we observed in terms of cell recruitment and cytokine secretion in our previous findings. Importantly, our data indicate that IL-17A and TNF-α promote the protein production of PD-L1 in an MSI AA cell line, which may result in the impairment of T cells' antitumor activity. Taken together, the differences in the immunologic profiles in AA when compared to CA suggest a deficiency of the appropriate immune defense mechanisms in this population that may contribute to the cancer health disparities among CRC patients.

Citation Format: Jenny E. Paredes, Ping Ji, Jone Garai, Marzia Spagnardi, Maria Munoz-Sagastibelza, Sayed Imtiaz, Gayle Mendez, Mubarak Akadri, Raavi Gupta, Mohamed Alshal, Maksim Agaronov, Henry Talus, Ellen Li, Jovanny Zabaleta, Laura Martello-Rooney, Jennie Williams. Tumor immune response in colon cancer African American patients and its role in cancer disparities [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C118.

Abstract C092: Immune characteristics of triple-negative breast cancer (TNBC) in Latin American women from Colombia

Background: Triple-negative breast cancer (TNBC) is an aggressive form of the disease with limited treatment options and poor survival. A series of retrospective studies established the presence of tumor-infiltrating lymphocytes (TILs) in most primary breast cancers, the number of which affect the response rate to chemotherapy in both neoadjuvant and adjuvant treatment contexts. A subset of TNBC is highly immunogenic, and recent studies have shown that understanding the specific immune profiles of tumors has implications both for treatment and prognosis. Most studies have been conducted in samples of women of European origin, and little is known about the immune profile of TNBCs in Hispanic/Latinas. The specific goal of our study was to test the association between immune characteristics of TNBC from Colombian patients and genetic ancestry proportions, to determine if genetic ancestry could be a relevant factor in defining the immune characteristics of TNBC.

Methods: We obtained 41 TNBC tissues through collaboration with the National Cancer Institute in Colombia along with demographic and clinical information. Genetic ancestry was estimated with a panel of 106 ancestry informative markers and the program STRUCTURE. RNA was extracted from FFPE tissues, qualified using Agilent chips, and used for sequencing at the Translational Genomics Core at the Stanley S. Scott Cancer Center. Using the TNBCtype program we confirmed 33 samples as TNBC. The program xCell was used for cell-signature identification based on RNAseq data. We explored associations between genetic ancestry and scores obtained for different immune cell-types and an overall immune score using linear regression. We analyzed the association for the following specific cells: Th1 cells, Th2 cells, Treg, CD4 T cells, CD4 TEM, CD4 memory T cells, CD8 T cells, CD8 TCM, CD8 TEM, CD8 naive T cells, macrophages, macrophages M1, macrophages M2, and mast cells.

Results: The overall immune score was positively associated with the proportion of African ancestry (p=0.049). Interestingly, we observed that Indigenous American ancestry was inversely associated with the Treg cell score while African ancestry was positively associated with it. Levels of these regulatory cells have been correlated with prognosis in ER- and triple-negative disease. We also found that CD4 T cell and CD4 memory T-cell scores were positively associated with African ancestry (P=0.006 and P=0.049 respectively).

Conclusions: Our results suggest that genetic ancestry among Latina women from Colombia is associated with certain immune characteristics of breast cancer. We need to further test these associations in a larger sample to confirm the findings, obtain additional insights, and understand their implications for TNBC treatment and prognosis among Latin American women.

Citation Format: Valentina A. Zavala, Laura C. Carrasquilla, Silvia J. Serrano-Gomez, Maria C. Sanabria-Salas, Melody C. Baddoo, Jone Garai, Jovanny Zabaleta, Laura Fejerman. Immune characteristics of triple-negative breast cancer (TNBC) in Latin American women from Colombia [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C092.

Angiopoietin-2 Inhibition Rescues Arteriovenous Malformation in a Smad4 Hereditary Hemorrhagic Telangiectasia Mouse Model

BACKGROUND

Hereditary hemorrhagic telangiectasia is an autosomal dominant vascular disorder caused by heterozygous, loss-of-function mutations in 4 transforming growth factor beta (TGFβ) pathway members, including the central transcriptional mediator of the TGFβ pathway, Smad4. Loss of Smad4 causes the formation of inappropriate, fragile connections between arteries and veins called arteriovenous malformations (AVMs), which can hemorrhage leading to stroke, aneurysm, or death. Unfortunately, the molecular mechanisms underlying AVM pathogenesis remain poorly understood, and the TGFβ downstream effectors responsible for hereditary hemorrhagic telangiectasia-associated AVM formation are currently unknown.

METHODS

To identify potential biological targets of the TGFβ pathway involved in AVM formation, we performed RNA- and chromatin immunoprecipitation-sequencing experiments on BMP9 (bone morphogenetic protein 9)-stimulated endothelial cells (ECs) and isolated ECs from a Smad4-inducible, EC-specific knockout ( Smad4-iECKO) mouse model that develops retinal AVMs. These sequencing studies identified the angiopoietin-Tek signaling pathway as a downstream target of SMAD4. We used monoclonal blocking antibodies to target a specific component in this pathway and assess its effects on AVM development.

RESULTS

Sequencing studies uncovered 212 potential biological targets involved in AVM formation, including the EC surface receptor, TEK (TEK receptor tyrosine kinase) and its antagonistic ligand, ANGPT2 (angiopoietin-2). In Smad4-iECKO mice, Angpt2 expression is robustly increased, whereas Tek levels are decreased, resulting in an overall reduction in angiopoietin-Tek signaling. We provide evidence that SMAD4 directly represses Angpt2 transcription in ECs. Inhibition of ANGPT2 function in Smad4-deficient mice, either before or after AVMs form, prevents and alleviates AVM formation and normalizes vessel diameters. These rescue effects are attributed to a reversion in EC morphological changes, such as cell size and shape that are altered in the absence of Smad4.

CONCLUSIONS

Our studies provide a novel mechanism whereby the loss of Smad4 causes increased Angpt2 transcription in ECs leading to AVM formation, increased blood vessel calibers, and changes in EC morphology in the retina. Blockade of ANGPT2 function in an in vivo Smad4 model of hereditary hemorrhagic telangiectasia alleviated these vascular phenotypes, further implicating ANGPT2 as an important TGFβ downstream mediator of AVM formation. Therefore, alternative approaches that target ANGPT2 function may have therapeutic value for the alleviation of hereditary hemorrhagic telangiectasia symptoms, such as AVMs.

Abstract 152: Gene expression and mutational load in colon tumors from African American patients

Colorectal cancer (CRC) is the third most common cancer among African Americans (AA) and when compared to Caucasian Americans (CA), they present with more advanced disease and lower survival rates. Our previous findings suggest that this may be related to the differential expression of genes linked to cell recruitment and immune response. Therefore, we aimed to investigate if differences in the cellular anti-tumor immune activity in AA and CA patients play a role in the disparate cancer progression observed between these populations. Our approach includes examining gene expression and immune cell recruitment at the tumor site and secretion of cytokines characteristic of effector T helper cells (Th) subsets in plasma. Lastly, we observed the expression of several proteins involved in apoptosis, stress, and drug resistance in response to treatment with 5-FU in two microsatellite unstable (MSI) CRC cell lines, one from an AA and one from a CA patient, and a microsatellite stable (MSS) CA colon cancer cell line.

Methods: We performed whole transcriptome sequencing in colon tumors, utilizing the NextSeq 500/550 High Output Kit v2.5 (Illumina). ELISA assays (RayBiotech) were used to examine the secretion of cytokines linked to Th subsets (Th1, Th2, Th17) and inflammation in plasma. Using IHC we evaluated the cell recruitment and activation of T and Natural Killer cells in colon tumors and by MetaCore we correlated gene expression to immune-oncology pathways. Western blots were used to evaluate the expression of cleaved caspase 3, phospho-JNK and RRM1 in the in-vitro models.

Results: ELISAs of plasma from CA and AA patients revealed a differential Th cytokines production patterns between early stage (I, II) and late stage (III) disease. Our gene expression results indicate that the immune profiles of AA patients differ from CA in the expression of 36 key genes and cytokines related to cellular anti-tumor activity, including FOXP3, Granzyme B and IL-17A, suggestive of more favorable prognosis in the CA tumors. Lastly, the MSI AA cell line showed sensitivity to 5-FU in terms of protein expression when compared to the CA cell lines.

Conclusions: Our gene expression findings demonstrated the differential expression of immunological pathways involved in immune-surveillance, cancer progression and antigen presentation in colon tumors from these two ethnicities. These results were in accordance with the systemic cytokines’ expression patterns observed in plasma and cell recruitment to the tumor sites. Importantly, our data indicates that treatment with 5-FU chemotherapy promotes apoptosis and stress in the MSI AA cell line but fails to produce the same effect in the CA cell lines at the same concentrations. Taken together, the differences in the immunological profiles in AA when compared to CA suggests a deficiency of the appropriate immune defense mechanisms in this population that may contribute to the cancer disparities among CRC patients.

Citation Format: Jenny Paredes, Jone Garai, Ping Ji, Sayed Imtiaz, Marzia Spagnardi, Maria Munoz-Sagastibelza, Mubarak Akadri, Raavi Gupta, Mohamed Alshal, Maksim Agaronov, Henry Talus, Ellen Li, Jennie Williams, Jovanny Zabaleta, Laura Martello-Rooney. Gene expression and mutational load in colon tumors from African American patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 152.

Assessing the spatial and temporal variability of bacterial communities in two Bardenpho wastewater treatment systems via Illumina MiSeq sequencing

Next generation sequencing provides new insights into the diversity and ecophysiology of bacteria communities throughout wastewater treatment plants (WWTP), as well as the fate of pathogens in wastewater treatment system. In the present study, we investigated the bacterial communities and human-associated Bacteroidales (HF183) marker in two WWTPs in North America that utilize Bardenpho treatment processes. Although, most pathogens were eliminated during wastewater treatment, some pathogenic bacteria were still observed in final effluents. The HF183 genetic marker demonstrated significant reductions between influent and post-Bardenpho treated samples in each WWTP, which coincided with changes in bacteria relative abundances and community compositions. Consistent with previous studies, the major phyla in wastewater samples were predominantly comprised by Proteobacteria (with Gammaproteobacteria and Alphaproteobacteria among the top two classes), Actinobacteria, Bacteroidetes, and Firmicutes. Dominant genera were often members of Proteobacteria and Firmicutes, including several pathogens of public health concern, such as Pseudomonas, Serratia, Streptococcus, Mycobacterium and Arcobacter. Pearson correlations were calculated to observe the seasonal variation of relative abundances of gene sequences at different levels based on the monthly average temperature. These findings profile how changes in bacterial communities can function as a robust method for monitoring wastewater treatment quality and performance for public and environmental health purposes.

Comparative analysis of miRNA profile in human dendritic cells infected with respiratory syncytial virus and human metapneumovirus

OBJECTIVE

Human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) are responsible for respiratory diseases, mostly in children. Despite the clinical and epidemiological similarities between these two pneumoviruses, they elicit different immune responses. This work aims to further our understanding of the differential immune response induced by these respiratory viruses by determining the changes of small non-coding RNAs (miRNAs), which regulate gene expression and are involved in numerous cellular processes including the immune system.

RESULTS

In the present study, we analyzed the expression of miRNA transcripts of human dendritic cells infected with RSV or HMPV by high throughput sequencing using Illumina sequencing technology. Further validation of miRNA expression by quantitative polymerase chain reaction indicated that HMPV infection up-regulated the expression of 2 miRNAs (hsa-miR-182-5p and hsa-miR-4634), while RSV infection induced significant expression of 3 miRNAs (hsa-miR-4448, hsa-miR-30a-5p and hsa-miR-4634). The predominant miRNA induced by both viruses was hsa-miR-4634.

Abstract A38: Identification of triple-negative breast cancer subtypes in Colombian patients

Background: Studies in Latinas have reported a high prevalence of ER/PR/HER2-negative (TNBC) and HER2-enriched breast tumors. In our ongoing study of breast cancer molecular characteristics of Colombian women (N=301), more than 20% of the tumors were classified as TNBC. Molecular analyses of this aggressive subtype of breast cancer in women of European ancestry have revealed additional molecular heterogeneity, which is associated with treatment response and survival. The goal of the present study was to explore the molecular profile of TNBC in a sample of Latin American women from Colombia and assess if genetic ancestry modified the gene expression profile.

Methods: We performed whole-transcriptome RNA-seq analysis in 48 TNBC tumors that were classified into intrinsic subtypes by immunohistochemistry (IHC) following St. Gallen 2015 surrogates. Genetic ancestry was estimated from a panel of 80 ancestry-informative markers (AIM). We categorized patients with TNBC according to the median of Indigenous ancestry (low Indigenous ancestry group: ancestry proportion below the median; high Indigenous ancestry: ancestry proportion above the median). We used top differentially expressed genes from Lehmann et al. (2011) (n=128) to explore the distribution of TNBC subtypes in our samples and to explore differences in the expression of these genes according to genetic ancestry.

Results: Unsupervised hierarchical clustering analysis did not show any clear clustering of the Colombian samples into defined subtypes based on expression of the 128 top differentially expressed genes reported by Lehmann et al. Subsequently, we selected genes that clustered together according to the definitions of TNBC subtypes of Lehmann, leaving a total of 35 genes for the analysis. Unsupervised hierarchical clustering using this list of genes identified two clusters, one predominantly observed for woman of high Indigenous American ancestry (average Indigenous American ancestry for this group was 45%) and another more common in women of low Indigenous ancestry (average Indigenous American ancestry for this group was 36%, p=0.04). The cluster that included most of the women with high Indigenous ancestry proportions was characterized by lower gene expression for the 35 genes compared to the cluster that included women with low Indigenous ancestry proportions.

Conclusions: Our results suggest differential expression of genes within TNBC breast cancer subtype according to genetic ancestry; nevertheless, we could not identify clear TNBC subtypes previously defined by Lehmann et al. in our study. Further analyses are needed to identify TNBC subtypes in Hispanic/Latina samples.

Citation Format: Silvia J. Serrano-Gomez, Maria Carolina Sanabria-Salas, Jone Garai, Melody C. Baddoo, Gustavo Hernandez-Suarez, Juan Carlos Mejia, Oscar Garcia, Lucio Miele, Laura Fejerman, Jovanny Zabaleta. Identification of triple-negative breast cancer subtypes in Colombian patients [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr A38.

IL1B-CGTC haplotype is associated with colorectal cancer in admixed individuals with increased African ancestry

Single-nucleotide polymorphisms (SNPs) in cytokine genes can affect gene expression and thereby modulate inflammation and carcinogenesis. However, the data on the association between SNPs in the interleukin 1 beta gene (IL1B) and colorectal cancer (CRC) are conflicting. We found an association between a 4-SNP haplotype block of the IL1B (-3737C/-1464G/-511T/-31C) and CRC risk, and this association was exclusively observed in individuals with a higher proportion of African ancestry, such as individuals from the Coastal Colombian region (odds ratio, OR 2.06; 95% CI 1.31–3.25; p < 0.01). Moreover, a significant interaction between this CRC risk haplotype and local African ancestry dosage was identified in locus 2q14 (p = 0.03). We conclude that Colombian individuals with high African ancestry proportions at locus 2q14 harbour more IL1B-CGTC copies and are consequently at an increased risk of CRC. This haplotype has been previously found to increase the IL1B promoter activity and is the most frequent haplotype in African Americans. Despite of limitations in the number of samples and the lack of functional analysis to examine the effect of these haplotypes on CRC cell lines, our results suggest that inflammation and ethnicity play a major role in the modulation of CRC risk.

Abstract B36: Biological and clinical significance of ID1/ID3/IGJ expression signature modulation in B-Acute lymphoblastic leukemia

Background. Acute lymphoblastic leukemia (ALL) in Hispanic populations represents a public health problem that requires priority attention because its incidence and mortality increase annually. Intensive chemotherapeutic schemes in the last decade in the United States and other countries and have led to higher rates of durable remissions. However, these schemes have shown disappointing results in Hispanic populations. In Colombia, for example, the median overall survival (OS) is less than 11.3 months, the event-free survival (EFS) is 7.34 months, and only 61% of patients achieve complete remission (CR). Therefore, it is interesting to explore the underlying molecular characteristics of the disease in Hispanic patients. Previously we identified a gene expression signature associated with response to induction treatment and outcome of adult Hispanic patients with B-ALL. These ID1, ID3 and IGJ seem to be involved in many tumorigenic processes. The goal of our study is identify the role of these genes in B-ALL and its relevance in the prognosis and progression of disease in an in vitro model.

Methods. CRISPR-Cas9 Gene Engineering and expression-ready ORF cDNA clones were used to either down-regulate or over-express, respectively, the expression of ID1, ID3 and IGJ genes in the adult B-ALL cell line NALM6. We used TaqMan to quantify the levels of mRNA expression of ID1/ID3/IGJ genes after over-expression. Protein expression by Flow Cytometry was used to verify silencing and over-expression of our 3-genes signature. Cell viability and proliferation were determined by anexin V-PI and MTT assay, respectively at 0, 24, 48, 72 and 96 hours after modulation. Cell cycle analysis was performed using BrdU and 7-AAD. Separately, increasing doses of cyclophosphamide, doxorubicin and cytarabine were used to determine the role of ID1, ID3, and IGJ genes in chemo resistance at 24, 48, 72, 96, and 144 hours. Total RNA from leukemic cells was isolated using Trizol method. We used microarray analysis to identify genes differentially expressed after silencing/overexpression. We performed Immunophenotype analysis of 43 B-ALL adult Hispanic patient Bone Marrow samples using the panel of antibodies recommended and standardized by the European consortium Euroflow. Correlation analysis were used to establish the association between our 3-Gene expression signature and the expression of surface markers currently used for diagnostic and follow-up of B-ALL patients.

Results. We observed that both overexpression and silencing of ID1, ID3 and IGJ modulated B-ALL cells cell cycle. ID1/ID3/IGJ overexpression resulted in a loss of S phase and arrest of the cells in the G0/G1 phase of the cell cycle. On the contrary, ID1/ID3/IGJ silencing induced a loss of G0/G1 phase and gain in the number of cells in G2/M and S phases. Gain-of-expression and loss-of-expression analyses using incremental doses of chemotherapy agents currently used in the B-ALL treatment, demonstrate that ID1/ID3/IGJ signature promotes drug resistance of the NALM6 B-ALL cell line. Clinically, patients with higher ID1/ID3/IGJ expression have high expression of CD20 and CD10 markers (aberrantly expressed in immature cells) and shorter OS and EFS. In addition, more than 2,000 genes that are differentially expressed in the cells with modulation of the expression of ID1/ID3/IGJ suggesting a complex network of biological processes implicated in the drug resistance and poor prognosis present in the patients with this 3-gene signature.

Conclusions. Our data identify the ID1/ID3/IGJ signature as possible modulator of molecular events during B-ALL differentiation, proliferation and drug resistance. These results highlight the potential role of this gene signature both as a risk stratification tool and as a candidate therapeutic target in Hispanic population.

Citation Format: Nataly Cruz-Rodriguez, Alba Lucia Combita, Jone Garai, Leonardo Jose Enciso, Sandra Milena Quijano, Silvia Serrano-Gomez, Li Li, Jovanny Zabaleta. Biological and clinical significance of ID1/ID3/IGJ expression signature modulation in B-Acute lymphoblastic leukemia. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr B36.

At the crossroad between obesity and gastric cancer

Obesity has reached epidemic proportions worldwide with disproportionate prevalence in different communities and ethnic groups. Recently, the American Medical Association recognized obesity as a disease, which is a significant milestone that opens the possibilities of treating obesity under standardized health plans. Obesity is an inflammatory disease characterized by elevated levels of biomarkers associated with abnormal lipid profiles, glucose levels, and blood pressure that lead to the onset of metabolic syndrome. Interestingly, inflammatory biomarkers, in particular, have been implicated in the risk of developing several types of cancer. Likewise, obesity has been linked to esophageal, breast, gallbladder, kidney, pancreatic, and colorectal cancers. Thus, there exists a link between obesity status and tumor appearance, which may be associated to the differential levels and the circulating profiles of several inflammatory molecules. For example, mediators of the inflammatory responses in both obesity and gastric cancer risk are the same: pro-inflammatory molecules produced by the activated cells infiltrating the inflamed tissues. These molecules trigger pathways of activation shared by obesity and cancer. Therefore, understanding how these different pathways are modulated would help reduce the impact that both diseases, and their concomitant existence, have on society.

Hormonal action of plant derived and anthropogenic non-steroidal estrogenic compounds: phytoestrogens and xenoestrogens

Herbivorous and omnivorous vertebrates have evolved in the presence of a variety of phytoestrogens, i.e., plant-derived compounds that can mimic, modulate or disrupt the actions of endogenous estrogens. Since the discovery of the estrus-inducing effects of some plant products in 1926, considerable effort has been devoted to the isolation and structural and pharmacological characterization of phytoestrogens. Recently, agricultural and industrial pollution has added anthropogenic estrogenic compounds to the list of environmental estrogens. Unlike phytoestrogens, these xenoestrogens tend to accumulate and persist in adipose tissue for decades and may cause long-lasting, adverse endocrine effects. Here we review the endocrine effects of known phytoestrogens and xenoestrogens with special emphasis on molecular structure-activity relationships. Phytoestrogens include flavonoids, isoflavonoids, chalcons, coumestans, stilbenes, lignans, ginsenosides and other saponins, as well as the recently discovered tetrahydrofurandiols. Fungal estrogenic compounds may enter the food chain via infested crops. Since some phytoestrogens have been shown to display organ-specific actions, pharmaceutical estrogen analogues with similar properties (selective estrogen receptor modulators, SERMs) are also discussed. Xenoestrogens include dichlorodiphenyltrichloroethane (DDT) and its metabolites, bisphenols, alkylphenols, dichlorophenols, methoxychlor, chlordecone, polychlorinated benzol derivatives (PCBs), and dioxins. While most of these compounds act through estrogen receptors alpha and beta, some of their effects may be mediated by other nuclear or membrane-bound receptors or receptor-independent mechanisms. Some might also interfere with the production and metabolism of ovarian estrogens. Better understanding of the molecular pharmacology of phyto- and xenoestrogens may result in the development of novel compounds with therapeutic utility and improved environmental protection.

Abstract 5127: Prosaposin down-modulation decreases metastatic prostate cancer cell adhesion, migration, and invasion

Factors responsible for invasive and metastatic progression of prostate cancer (PCa) remain largely unknown. Previously, we reported cloning of prosaposin (PSAP) and its genomic amplification and/or overexpression in several androgen-independent metastatic PCa cell lines and lymph node metastases. PSAP is the lysosomal precursor of saposins, which serve as activators for lysosomal hydrolases involved in the degradation of ceramide (Cer) and other sphingolipids. Our current data show that, in metastatic PCa cells, stable down-modulation of PSAP by RNA-interference via a lysosomal proteolysis-dependent pathway decreased β1A-integrin expression, its cell-surface clustering, and adhesion to basement membrane proteins; led to disassembly of focal adhesion complex; and decreased phosphorylative activity of focal adhesion kinase and its downstream adaptor molecule, paxillin. Cathepsin D (CathD) expression and proteolytic activity, migration, and invasion were also significantly decreased in PSAP knock-down cells. Transient-transfection studies with β1A integrin- or CathD-siRNA oligos confirmed the cause and effect relationship between PSAP and CathD or PSAP and Cer-β1A integrin, regulating PCa cell migration and invasion. Our findings suggest that by a coordinated regulation of Cer levels, CathD and β1A-integrin expression, and attenuation of “inside-out” integrin-signaling pathway, PSAP is involved in PCa invasion and therefore might be used as a molecular target for PCa therapy.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5127.

Prosaposin down-modulation decreases metastatic prostate cancer cell adhesion, migration, and invasion

Background

Factors responsible for invasive and metastatic progression of prostate cancer (PCa) remain largely unknown. Previously, we reported cloning of prosaposin (PSAP) and its genomic amplification and/or overexpression in several androgen-independent metastatic PCa cell lines and lymph node metastases. PSAP is the lysosomal precursor of saposins, which serve as activators for lysosomal hydrolases involved in the degradation of ceramide (Cer) and other sphingolipids.

Results

Our current data show that, in metastatic PCa cells, stable down-modulation of PSAP by RNA-interference via a lysosomal proteolysis-dependent pathway decreased β_1A-integrin expression, its cell-surface clustering, and adhesion to basement membrane proteins; led to disassembly of focal adhesion complex; and decreased phosphorylative activity of focal adhesion kinase and its downstream adaptor molecule, paxillin. Cathepsin D (CathD) expression and proteolytic activity, migration, and invasion were also significantly decreased in PSAP knock-down cells. Transient-transfection studies with β_1A integrin- or CathD-siRNA oligos confirmed the cause and effect relationship between PSAP and CathD or PSAP and Cer-β_1A integrin, regulating PCa cell migration and invasion.

Conclusion

Our findings suggest that by a coordinated regulation of Cer levels, CathD and β_1A-integrin expression, and attenuation of "inside-out" integrin-signaling pathway, PSAP is involved in PCa invasion and therefore might be used as a molecular target for PCa therapy.

Charcoal stripping augments type II oestradiol binding in cytoplasmic fraction of rat hypothalami

Type II [3H]oestradiol binding was assessed by charcoal method in the low speed cytoplasmic fraction of intact female rat hypothalami. Augmented binding was observed after charcoal pretreatment applied prior to binding assay. On the other hand, loss of low affinity oestradiol binding was demonstrated after addition of protein-free ultrafiltrates of the cytosol from hypothalami or uteri. The presence of a cytosolic inhibitor activity specific for type II oestradiol binding in hypothalami is considered.

Issues to debate on the Women's Health Initiative: estrogen: an instrument or the conductor of the orchestra?

Although it is well known that cyclic production of sex hormones is essential to establish reproductive function and female characteristics, distant impacts of the activity of the female endocrine system result from a concert of delicate mechanisms. Estrogen is rather an instrument than a conductor in this physiological orchestra of the female. Thus, controversies in the explanation of results from studies on hormone replacement therapy (HRT) and cardiovascular disease (CVD) prevention might be eliminated, if we analyse not only the role of estrogen but a broader spectrum of factors leading to CVD. Authors would like to hypothesize that haemorheological changes in women around menopause, such as increased blood and plasma viscosity, haematocrit and fibrinogen, are largely responsible for the increased mortality in the post-menopausal life period. We believe that a cyclic withdrawal bleeding establishes a more favourable haemorheological condition, thus, sequentially administered estrogen might be protective in post-menopausal women. Nevertheless, other factors, that decrease blood viscosity, such as daily exercise, intake of ample amount of fluids as well as ideal nutrition, are equally important. We are confident that sequential HRT, as well as healthy life style and risk prevention programmes have their proper place in the management of this issue.

Hepatic dysfunction in development of menopausal hot flushes?

Obese menopausal women tend to suffer more frequently and more severely from hot flushes, though they have higher residual estrogen levels due to the conversion of adrenal androgens in fat tissue. Phytoestrogens, while not exhibiting clinically relevant estrogenic effects on peripheral reproductive tissues, seem to alleviate hot flushes in doses attainable with dietary supplementation. This paper aims to address these controversies. A synergistic action of obesity and estrogens may cause hepatic dysfunction involving inflammatory Kupffer cell activation and generation of pyrogenic signals that reach the thermoregulatory centers via the vagal route. Sudden withdrawal of this perpetual pyrogenic impetus at the onset of menopause results in a thermoregulatory imbalance. The occasional downward sliding of the thermoregulatory setpoint serves to trigger the hot flush event. Repercussions of this theory involve a possible resolution for the paradox of why estrogen-sensitive cancers manifest more frequently at the age when endogenous estrogen levels decline.

Epidermal growth factor activates reproductive behavior independent of ovarian steroids in female rodents

Sex steroids exert profound influence on neural development and function through activation of intranuclear receptors. However, during sexual differentiation and at onset of puberty, intracerebral estrogen (E) availability is subsequent to these effects. The potent mitogen epidermal growth factor (EGF) activates estrogen receptor (ER)-dependent transcription in cultured cells in the absence of exogenous E. Since reproductive behavior in female rodents is the result of E-dependent transcriptional activity and protein synthesis, lordosis serves as a well established in vivo model for probing cellular and molecular mechanisms of steroid receptor-dependent behavior. Here we demonstrate that EGF can signal through the classical E receptor (ERalpha) to alter in vivo function in rodent central nervous system. EGF and EGF receptor ligands induced lordosis in a dose- and time-dependent manner in the absence of steroid treatment in ovariectomized rats and mice. Using antisense oligonucleotides, pharmacological and antibody blockade, and mutant mice, we also report that this behavioral responsiveness is mediated through ERalpha by specific stimulation of membrane-bound EGF receptors and EGF receptor-specific tyrosine kinase rather than by direct ligand activation of the ERalpha. Of biological significance, delayed onset of puberty and the absence of synchronization between reproductive behavior and ovulation was detected in intact mutant Wa-2 mice that express a naturally occurring point mutation in the EGF receptor. To our surprise, EGF-mediated behavior was independent of progesterone (P) and progesterone receptor (PR) since antiprogestins, PR antisense oligonucleotides, and targeted disruption of PR in ovariectomized transgenic mice failed to impede the display of lordosis after EGF. Finally, we also found that another growth factor, insulin-like growth factor-1, which provokes ER-dependent transcription in vitro, activates mating behavior in a similar E-independent manner. Thus, growth factor mediation of ER-targeted function may be a universal feature in the rodent central nervous system, raising critical questions about the role of growth factors in mediating ER-dependent processes in development and reproduction.

In vivo regulation of central nervous system progesterone receptors: cocaine induces steroid-dependent behavior through dopamine transporter modulation of D5 receptors in rats

To characterize the membrane pathway by which the cocaine-sensitive dopamine transporter (DAT) modulates progesterone receptor activation, steroid-dependent behavior lordosis was used in estrogen-primed ovariectomized Sprague-Dawley rats with stereotaxic implanted third ventricle cannulas. Lordosis in response to solicitous males was observed in females after intercerebral ventricular administration of DAT antagonists WIN35,428 (80 ng) and cocaine (0.016-1.6 micrograms). Significantly, antisense oligonucleotides (AS) to DAT mRNA also induced reproductive behavior. In contrast, the D1-D2 receptor membrane-repopulation inhibitor N-ethoxycarbonyl-2 ethoxy-1,2-dihydroquinoline and the D1-like antagonist SCH23390 blocked cocaine-inducible behavior. Further, facilitation of behavior by AS to the DAT was suppressed by N-ethoxycarbonyl-2 ethoxy-1,2-dihydroquinoline. Behavior was not dependent on D2 receptors, since animals pretreated with the D2 antagonist sulpride displayed lordosis after cocaine challenge. Antisense oligonucleotides to D5 but not D1 dopamine receptor mRNA suppressed reproductive behavior associated with cocaine. Microinjections of cocaine to the ventromedial nucleus (VMN) but not arcuate nucleus or preoptic area potentiated lordosis, suggesting the functional presence of DAT in the VMN. Finally, cocaine facilitation of behavior was blocked by both antiprogestin RU486 and progesterone receptor AS microinjected into either the third ventricle or the VMN. Collectively, the data provide strong evidence for cocaine modulation of reproductive behavior through presynaptic cocaine-sensitive dopamine transporters and postsynaptic D5 dopamine receptor mediation of progesterone receptor-dependent behavior in rat central nervous system.

Dopaminergic regulation of progesterone receptors: brain D5 dopamine receptors mediate induction of lordosis by D1-like agonists in rats

To characterize the signaling pathway by which the neurotransmitter dopamine modulates progesterone receptor (PR) activation, the steroid-dependent behavior lordosis was used in estrogen-primed ovariectomized Sprague-Dawley rats with stereotaxic implanted third ventricle cannulas. Lordosis was observed in response to solicitous males in females after central administration of the D1-like agonist SKF38393 and three of its analogs (SKF77434, SKF75640, and SKF85174). In contrast, D1-like antagonist SCH23390 and D1-like/D2 repopulation inhibitor EEDQ blocked behavior inducible by the D1-like agonists. Further, antisense oligonucleotides to D5, but not D1, dopamine receptor mRNA suppressed reproductive behavior associated with D1-like stimulation. This finding provides strong evidence that dopaminergic modulation of lordosis is mediated by the novel D5 dopamine receptor. Although D1, but not D5, dopamine receptor mRNAs were detected in the ventromedial nucleus (VMN) by in situ hybridization, agonists microinjected into the VMN, but not into the arcuate nucleus or preoptic area, induced lordosis, suggesting the functional presence of D5 dopamine receptors in the VMN. Also in support, D5 receptor mRNA antisense microinjected into the VMN blocked the subsequent induction of lordosis by D1-like agonists. Finally, facilitation of sex behavior by D1-like agonists was blocked by the antiprogestin RU38486 and PR antisense oligonucleotide. Collectively, the data provide strong evidence for dopaminergic modulation of reproductive behavior through D5 dopamine receptor-mediated modulation of PR-dependent behavior in rat CNS.