Decoding the role of microRNA dysregulation in the interplay of pancreatic cancer and type 2 diabetes

This study examines the complex relationship between pancreatic cancer (PC) and type 2 diabetes (T2D) by focusing on the role of microRNAs (miRNAs). miRNAs are small non-coding RNAs that regulate gene expression and have been implicated in many diseases, including T2D and cancer. To begin, we conducted a literature review to identify miRNAs associated with the PC-T2D link. However, we found limited research on this specific association, with most studies focusing on the antitumor effects of metformin. Furthermore, we performed a bioinformatics analysis to identify new potential miRNAs that might be relevant in the context of PC-T2D. First, we identified miRNAs and gene expression alterations common to both diseases using publicly available datasets. Subsequently, we performed an integrative analysis between the identified miRNAs and genes alterations. As a result, we identified nine miRNAs that could potentially play an important role in the interplay between PC and T2D. These miRNAs have the potential to influence nearby cells and distant tissues, affecting critical processes like extracellular matrix remodeling and cell adhesion, ultimately contributing to the development of T2D or PC. Taken together, these analyses underscore the importance of further exploring the role of miRNAs in the complex interplay of PC and T2D.

Prognostic Factors of Long-Term Outcomes after Primary Chemo-Radiotherapy in Non-Metastatic Anal Squamous Cell Carcinoma: An International Bicentric Cohort

Anal squamous cell carcinoma (ASCC) is a rare malignancy with a rising incidence associated with human papillomavirus (HPV) infection. The locally advanced disease is associated with a 30% rate of treatment failure after standard chemoradiotherapy (CRT). We aimed to elucidate the prognostic factors for ASCC after curative CRT. A retrospective multicenter study of 176 consecutive patients with ASCC having completed CRT treated between 2010 and 2017 at two centers was performed. Complete response (CR), disease-free survival (DFS), and overall survival (OS) were analyzed by Kaplan–Meier estimates with log-rank tests. The hierarchical clustering on principal components (HCPC) method was employed in an unsupervised and multivariate approach. The CR rate was 70% and was predictive of DFS (p < 0.0001) and OS (p < 0.0001), where non-CR cases were associated with shorter DFS (HR = 16.5, 95% CI 8.19–33.21) and OS (HR = 8.42, 95% CI 3.77–18.81) in a univariate analysis. The median follow-up was 38 months, with a 3-year DFS of 71%. The prognostic factors for DFS were cT1-T2 (p = 0.0002), N0 (p = 0.035), HIV-positive (p = 0.047), HIV-HPV coinfection (p = 0.018), and well-differentiated tumors (p = 0.037). The three-year OS was 81.6%. Female sex (p = 0.05), cT1-T2 (p = 0.02) and well-differentiated tumors (p = 0.003) were associated with better OS. The unsupervised analysis demonstrated a clear segregation of patients in three clusters, identifying that poor prognosis clusters associated with shorter DFS (HR = 1.74 95% CI = 1.25–2.42, p = 0.0008) were enriched with the locally advanced disease, anal canal location, HIV-HPV coinfection, and non-CR. In conclusion, our results reinforce the prognostic value of T stage, N stage, sex, differentiation status, tumor location, and HIV-HPV coinfection in ASCC after CRT.

MALINC1 an Immune-Related Long Non-Coding RNA Associated with Early-Stage Breast Cancer Progression

Simple Summary

Here we characterize the phenotypic and molecular effects of MALINC1, a long non-coding RNA (lncRNA) that we found significantly upregulated in premalignant ductal carcinoma in-situ lesions. We provide evidence that MALINC1 behaves as an oncogenic and immune-related lncRNA involved with early-stage breast cancer progression, showing prognostic and predictive value to immunotherapy in invasive breast carcinomas.

Abstract

Long non-coding RNAs are increasingly being recognized as cancer biomarkers in various malignancies, acting as either tumor suppressors or oncogenes. The long non-coding MALINC1 intergenic RNA was identified as significantly upregulated in breast ductal carcinoma in situ. The aim of this study was to characterize MALINC1 expression, localization, and phenotypic and molecular effects in non-invasive and invasive breast cancer cells. We determined that MALINC1 is an estrogen–estrogen receptor-modulated lncRNA enriched in the cytoplasmic fraction of luminal A/B breast cancer cells that is associated with worse overall survival in patients with primary invasive breast carcinomas. Transcriptomic studies in normal and DCIS cells identified the main signaling pathways modulated by MALINC1, which mainly involve bioprocesses related to innate and adaptive immune responses, extracellular matrix remodeling, cell adhesion, and activation of AP-1 signaling pathway. We determined that MALINC1 induces premalignant phenotypic changes by increasing cell migration in normal breast cells. Moreover, high MALINC1 expression in invasive carcinomas was associated with a pro-tumorigenic immune environment and a favorable predicted response to immunotherapy both in luminal and basal-like subtypes compared with low-MALINC1-expression tumors. We conclude that MALINC1 behaves as an oncogenic and immune-related lncRNA involved with early-stage breast cancer progression.

Prognostic Impact of An Integrative Landscape of Clinical, Immune, and Molecular Features in Non-Metastatic Rectal Cancer

Rectal Cancer (RC) is a complex disease that involves highly variable treatment responses. Currently, there is a lack of reliable markers beyond TNM to deliver a personalized treatment in a cancer setting where the goal is a curative treatment. Here, we performed an integrated characterization of the predictive and prognostic role of clinical features, mismatch-repair deficiency markers, HER2, CDX2, PD-L1 expression, and CD3-CD8+ tumor-infiltrating lymphocytes (TILs) coupled with targeted DNA sequencing of 76 non-metastatic RC patients assigned to total mesorectal excision upfront (TME; n = 15) or neoadjuvant chemo-radiotherapy treatment (nCRT; n = 61) followed by TME. Eighty-two percent of RC cases displayed mutations affecting cancer driver genes such as TP53, APC, KRAS, ATM, and PIK3CA. Good response to nCRT treatment was observed in approximately 40% of the RC cases, and poor pathological tumor regression was significantly associated with worse disease-free survival (DFS, HR = 3.45; 95%CI = 1.14-10.4; p = 0.028). High neutrophils-platelets score (NPS) (OR = 10.52; 95%CI=1.34-82.6; p = 0.025) and KRAS mutated cases (OR = 5.49; 95%CI = 1.06-28.4; p = 0.042) were identified as independent predictive factors of poor response to nCRT treatment in a multivariate analysis. Furthermore, a Cox proportional-hazard model showed that the KRAS mutational status was an independent prognostic factor associated with higher risk of local recurrence (HR = 9.68; 95%CI = 1.01-93.2; p <0.05) and shorter DFS (HR = 2.55; 95%CI = 1.05-6.21; p <0.05), while high CEA serum levels were associated with poor DFS (HR = 2.63; 95%CI = 1.01-6.85; p <0.05). Integrated clinical and molecular-based unsupervised analysis allowed us to identify two RC prognostic groups (cluster 1 and cluster 2) associated with disease-specific OS (HR = 20.64; 95%CI = 2.63-162.2; p <0.0001), metastasis-free survival (HR = 3.67; 95%CI = 1.22-11; p = 0.012), local recurrence-free survival (HR = 3.34; 95%CI = 0.96-11.6; p = 0.043) and worse DFS (HR = 2.68; 95%CI = 1.18-6.06; p = 0.012). The worst prognosis cluster 2 was enriched by stage III high-risk clinical tumors, poor responders to nCRT, with low TILs density and high frequency of KRAS and TP53 mutated cases compared with the best prognosis cluster 1 (p <0.05). Overall, this study provides a comprehensive and integrated characterization of non-metastatic RC cases as a new insight to deliver a personalized therapeutic approach.

RHBDD2‑WWOX protein interaction during proliferative and differentiated stages in normal and breast cancer cells

Rhomboid pseudoproteases are catalytically inactive members of the rhomboid superfamily that modulate the traffic, turnover and activity of their target proteins. Rhomboid domain containing 2 (RHBDD2) is a rhomboid family member overexpressed during mammary gland development and advanced stages of breast cancer. Interactome profiling studies have identified RHBDD2 as a novel binding partner of WW domain‑containing oxidoreductase (WWOX) protein. The present study characterized the RHBDD2‑WWOX interaction in proliferating and differentiated stages of normal mammary and breast cancer cells by co‑immunoprecipitation and confocal microscopy. Normal breast and proliferating cancer cells showed significantly increased RHBDD2 mRNA levels compared with their differentiated counterparts. WWOX mRNA was primarily expressed in differentiated cells. WWOX co‑precipitated with RHBDD2, indicating that endogenous RHBDD2 and WWOX were physically associated in normal and breast cancer proliferating cells compared with the differentiated stage. Co‑localization assays corroborated the co‑immunoprecipitation results, demonstrating the RHBDD2‑WWOX protein interaction in normal and proliferating breast cancer cells. RHBDD2 harbors a conserved LPPY motif at the C‑terminus region that directly interacted with the WW domains of WWOX. Since WWOX serves as an inhibitor of the TGFβ/SMAD3 signaling pathway in breast cells, modulation of SMAD3 target genes was analyzed in proliferating and differentiated mammary cells and in RHBDD2 silencing assays. Increased expression levels of SMAD3‑regulated genes were detected in proliferating cells compared with their differentiated counterparts. Follistatin and angiopoietin‑like 4 mRNA was significantly downregulated in RHBDD2 transiently silenced cells compared with scrambled control small interfering RNA. Based on these results, WWOX was suggested to be a novel RHBDD2 target protein involved in the modulation of breast epithelial cell proliferation and differentiation.

Identification of an AP1-ZFP36 Regulatory Network Associated with Breast Cancer Prognosis

It has been established that ZFP36 (also known as Tristetraprolin or TTP) promotes mRNA degradation of proteins involved in inflammation, proliferation and tumor invasiveness. In mammary epithelial cells ZFP36 expression is induced by STAT5 activation during lactogenesis, while in breast cancer ZFP36 expression is associated with lower grade and better prognosis. Here, we show that the AP-1 transcription factor components, i.e. JUN, JUNB, FOS, FOSB, in addition to DUSP1, EGR1, NR4A1, IER2 and BTG2, behave as a conserved co-regulated group of genes whose expression is associated to ZFP36 in cancer cells. In fact, a significant down-modulation of this gene network is observed in breast, liver, lung, kidney, and thyroid carcinomas compared to their normal counterparts. In breast cancer, the normal-like and Luminal A, show the highest expression of the ZFP36 gene network among the other intrinsic subtypes and patients with low expression of these genes display poor prognosis. It is also proposed that AP-1 regulates ZFP36 expression through responsive elements detected in the promoter region of this gene. Culture assays show that AP-1 activity induces ZFP36 expression in mammary cells in response to prolactin (PRL) treatment thorough ERK1/2 activation. These results suggest that JUN, JUNB, FOS and FOSB are not only co-expressed, but would also play a relevant role in regulating ZFP36 expression in mammary epithelial cells.

RHBDD2 overexpression promotes a chemoresistant and invasive phenotype to rectal cancer tumors via modulating UPR and focal adhesion genes

The current standard of care for locally advanced rectal cancer (RC) is neoadjuvant radio-chemotherapy (NRC) with 5-fluorouracil (5Fu) as the main drug, followed by surgery and adjuvant chemotherapy. While a group of patients will achieve a pathological complete response, a significant percentage will not respond to the treatment. The Unfolding Protein Response (UPR) pathway is generally activated in tumors and results in resistance to radio-chemotherapy. We previously showed that RHBDD2 gene is overexpressed in the advanced stages of colorectal cancer (CRC) and that it could modulate the UPR pathway. Moreover, RHBDD2 expression is induced by 5Fu. In this study, we demonstrate that the overexpression of RHBDD2 in CACO2 cell line confers resistance to 5Fu, favors cell migration, adhesion and proliferation and has a profound impact on the expression of both, the UPR genes BiP, PERK and CHOP, and on the cell adhesion genes FAK and PXN. We also determined that RHBDD2 binds to BiP protein, the master UPR regulator. Finally, we confirmed that a high expression of RHBDD2 in RC tumors after NRC treatment is associated with the development of local or distant metastases. The collected evidence positions RHBDD2 as a promising prognostic biomarker to predict the response to neoadjuvant therapy in patients with RC.

Comparative Analysis of the Biosimilar and Innovative G-CSF Modulated Pathways on Umbilical Cord Blood-Derived Mononuclear Cells

Biosimilars of granulocyte colony-stimulating factor (G-CSF) have been routinely introduced into clinical practice. However, not functional genomics characterization has been performed yet in comparison with the innovator G-CSF. This study aimed to evaluate the transcriptomic changes in an in vitro model of umbilical cord blood cells (UBC) exposed to G-CSF for the identification of their modulated pathways. Umbilical cord blood cells-derived mononuclear cells (MNCs) were treated with biosimilar and innovator G-CSF for further gene expression profiling analysis using a microarray-based platform. Comparative analysis of biosimilar and innovator G-CSF gene expression signatures allowed us to identify the most commonly modulated pathways by both drugs. In brief, we observed predominantly upmodulation of transcripts related to PI3K-Akt, NF-kappaB, and tumor necrosis factor (TNF) signaling pathways as well as transcripts related to negative regulation of apoptotic process among others. In addition, hematopoietic colony-forming cell assays corroborate the G-CSF phenotypic effects over UBC-derived MNCs. In conclusion, our study suggests that G-CSF impacts UBC-derived cells through the modulation of several signaling pathways associated with cell survival, migration, and proliferation. The concordance observed between biosimilar and innovator G-CSF emphasizes their similarity in regards to their specificity and biological responses.

Breast cancer cutaneous metastases are associated to uMUC1 and sialyl Lewis x and to highly malignant primary tumors

Breast cancer spreading to different organs have been related to different molecules and mechanisms, but cutaneous metastasis remains unexplored. Increasing evidence showed that MUC1 and some of its carbohydrate associated antigens may be implicated in breast cancer metastasis. In this study we analyzed these tumor markers in order to identify breast cancer cutaneous metastatic profiles. A cohort of 26 primary tumors from breast cancer patients with cutaneous metastases were included; also, cutaneous and lymphatic node metastatic samples and primary tumors from breast cancer patients without metastases were analysed. Immunohistochemical (IHC) studies demonstrated that both underglycosylated MUC1 (uMUC1) and sialyl Lewis x (sLex) to be positively associated with cutaneous metastatic primary tumors (p < 0.05). Notably, a high percentage of tumors with cutaneous metastases were characterized as triple negative and Her2+ tumors (37.5 % and 29 %, respectively). Some discordant results were found between primary tumors and their matched cutaneous metastases. To determine if MUC1 variants may be carriers of carbohydrate antigens, subcellular fractions from a cutaneous metastatic lesion were obtained, immunoprecipitated and analyzed by Western blot. We found that the isolated uMUC1 with a molecular weight of>200 kDa was also the site for binding of anti-sLex MAb; in coincidence, a high correlation of positive IHC expression of both markers was observed. Our findings confirm that breast cancer cutaneous metastases were associated to highly malignant primary tumors and sustain the hypothesis that u-MUC1 and sLe x may drive breast cancer cutaneous metastases.

Heme Oxygenase-1 Has an Antitumor Role in Breast Cancer

Aims: Heme oxygenase-1 (HO-1) is an enzyme involved in cellular responses to oxidative stress and has also been shown to regulate processes related to cancer progression. In this regard, HO-1 has been shown to display a dual effect with either antitumor or protumor activity, which is also true for breast cancer (BC). In this work, we address this discrepancy regarding the role of HO-1 in BC. Results: HO-1 was detected in human BC tissues, and its protein levels correlated with reduced tumor size and longer overall survival time of patients, thus suggesting the clinical importance of HO-1 in this type of cancer. Contrariwise, nuclear localization of HO-1 correlated with higher tumor grade suggesting that the effect of HO-1 is dependent on its cellular localization. In vivo experiments showed that both pharmacological activation and genetic overexpression of HO-1 reduce the tumor burden in two different animal models of BC. Furthermore, the pharmacological and genetic activation of HO-1 in several BC cell lines reduce the cellular viability by inducing apoptosis and cell cycle arrest and decrease the cellular migration and invasion rates by modulating pathways involved in the epithelial-mesenchymal transition. Furthermore, HO-1 activation impaired in vivo the metastatic dissemination. Innovation and Conclusion: By using various BC cell lines and animal models as well as human tumor samples, we demonstrated that total HO-1 displays antitumor activities in BC. Furthermore, our study suggests that HO-1 subcellular localization may explain the differential effects observed for the protein in different tumor types.

Small non-coding RNA landscape is modified by GPAT2 silencing in MDA-MB-231 cells

Glycerol-3-phosphate acyltransferase-2 is a member of "cancer-testis gene" family. Initially linked to lipid metabolism, this gene has been recently found involved also in PIWI-interacting RNAs biogenesis in germline stem cells. To investigate its role in piRNA metabolism in cancer, the gene was silenced in MDA-MB-231 breast cancer cells and small RNA sequencing was applied. PIWI-interacting RNAs and tRNA-derived fragments expression profiles showed changes following GPAT2 silencing. Interestingly, a marked shift in length distribution for both small RNAs was detected in GPAT2-silenced cells. Most downregulated PIWI-interacting RNAs are single copy in the genome, intragenic, hosted in snoRNAs and previously found to be upregulated in cancer cells. Putative targets of these PIWI-interacting RNAs are linked to lipid metabolism. Downregulated tRNA derived fragments derived from, so-called 'differentiation tRNAs', whereas upregulated ones derived from proliferation-linked tRNAs. miRNA amounts decrease after Glycerol-3-phosphate acyltransferase-2 silencing and functional enrichment analysis of deregulated miRNA putative targets point to mitochondrial biogenesis, IGF1R signaling and oxidative metabolism of lipids and lipoproteins. In addition, miRNAs known to be overexpressed in breast cancer tumors with poor prognosis where found downregulated in GPAT2-silenced cells. In conclusion, GPAT2 silencing quantitatively and qualitatively affects the population of PIWI-interacting RNAs, tRNA derived fragments and miRNAs which, in combination, result in a more differentiated cancer cell phenotype.

Alternative splicing variant of RHBDD2 is associated with cell stress response and breast cancer progression

RHBDD2 is an intramembrane pseudoprotease member of the Rhomboid superfamily. Our previous studies in breast and colorectal cancer indicate an association between RHBDD2 overexpression and advanced tumor stages. Two alternative transcriptional variants have been described for RHBDD2, which would be encoding for different RHBDD2 protein isoforms. The expression of these RHBDD2 variants/isoforms and its association with breast cancer was the focus of this study. First, expression of RHBDD2 splicing variants was evaluated in normal and breast tumor samples. RHBDD2 variant 2 overexpression was detected in tumors in respect to normal breast tissues at the mRNA and protein levels (P<0.05). Moreover, RHBDD2 variant 2 expression was associated with poor prognostic factors such as basal‑like intrinsic subtype (P<0.05), high proliferation (P<0.01) and long‑term risk‑of‑recurrence (P<0.01) scores. Second, the expression of both variants was evaluated under nutritional‑deprived conditions in breast cancer cell lines. Results demonstrated that RHBDD2 splicing was switched from mRNA variant 1 to variant 2 in association with a significant increment of protein isoform B in response to glucose starvation treatment. Therefore, we propose that the switch from the RHBDD2 variant 1, expressed in normal epithelial cells, to variant 2 occurs as an adaptive phenotype to bypass the stressful tumor microenvironment and promote tumor progression. Finally, the RHBDD2 subcellular localization was corroborated at the Golgi apparatus and their associated v‑SNARE transport vesicles, suggesting a putative new role for RHBDD2 in the protein trafficking of human breast cancer cells.

Polymorphic Variants in Oxidative Stress Genes and Acute Toxicity in Breast Cancer Patients Receiving Radiotherapy

Purpose

Reactive oxygen species (ROS) are generated as an indirect product of radiation therapy (RT). Genetic variation in genes related to ROS metabolism may influence the level of RT-induced adverse effects. We evaluated the potential association of single nucleotide polymorphism (SNP)–related response to radiotherapy injury in breast cancer patients undergoing RT.

Materials and Methods

Eighty patients receiving conventional RT were included. Acute effects were evaluated according to the Radiation Therapy Oncology Group (RTOG) scores. DNA was extracted from blood and buccal swab samples. SNPs were genotyped for GSTP1, GSTA1, SOD2, and NOS3 genes by polymerase chain reaction–based restriction fragment length polymorphism. Univariate analysis (odds ratios [ORs] and 95% confidence interval [CI]) and principal component analysis were used for correlation of SNPs and factors related to risk of developing ≥ grade 2 acute effects.

Results

Sixty-five patients (81.2%) showed side effects, 32 (40%) presented moderate to severe acute skin toxicity, and 33 (41.2%) manifested minimal acute skin reactions by the end of treatment. In both univariate and multivariate analyses, nominally significant associations were found among body mass index (OR, 3.14; 95% CI, 8.5338 to 1.1274; p=0.022), breast size (OR, 5.11; 95% CI, 17.04 to 1.54; p=0.004), and grade ≥ 2 acute radiation skin toxicity. A significant association was also observed between NOS3 G894T polymorphism (OR, 9.8; 95% CI, 211.6 to 0.45; p=0.041) and grade ≥ 2 acute radiation skin toxicity in patients with neo-adjuvant chemotherapy treatment.

Conclusion

The analysis of the factors involved in individual radiosensitivity contributed to the understanding of the mechanisms underlying this trait.

Spatiotemporal expression of Rhomboid domain containing 2 (Rhbdd2) during rat development

Over the last few years rhomboid genes have gained interest because of its association with cancer and neurodegenerative diseases. In previous studies, we demonstrated that human RHBDD2 is over-expressed in the advanced stages of breast and colorectal cancers, suggesting a favorable role in cell proliferation. So far little is known about the expression of RHBDD2 in other tissues and other species, and because of similarities between cancer and embryonic cells, this study focused on the evaluation of Rhbdd2 expression in embryonic and adult rat tissues. By IHC and RT-PCR, Rhbdd2 was identified in early stages of most tissues analyzed, with high expression in brain, spinal cord, kidney and embryonic skin. In adult tissues, the expression remained elevated while salivary glands became positive. Furthermore, Rhbdd2 showed a high expression in the most proliferative stages of the rat mammary gland. Indeed, similar findings were observed in the mouse mammary epithelial cell line HC11, in which Rhbdd2 resides in the Golgi apparatus, and at different stages of mouse mammary gland development. Therefore, Rhbdd2 would be implicated in embryonic and adult tissue proliferation.

Rhomboid family gene expression profiling in breast normal tissue and tumor samples

Rhomboid is an evolutionary conserved and functionally diversified group of proteins composed of proteolytically active and inactive members that are involved in the modulation of multiple biological processes such as epidermal growth factor receptor signaling pathway, endoplasmic reticulum-associated degradation, cell death, and proliferation. Recently, several human rhomboid genes have been associated with the development of chronic myeloid leukemia and pituitary, colorectal, ovarian, and breast cancers. In this study, we evaluated the mRNA and protein expression profiles of rhomboid genes in cancer cell lines and breast tissue/tumor samples. In silico analysis of publicly available gene expression datasets showed that different rhomboid genes are specifically expressed according to the breast cancer intrinsic subtypes. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis showed a significant RHBDD2 mRNA overexpression in advanced breast cancer compared with normal tissue samples (p = 0.012). In addition, we found that RHBDL2 and PARL mRNA expression was associated with a low/intermediate histologic tumor grade (p = 0.024 and p = 0.015, respectively). Immunohistochemistry analysis showed a significant increase of RHBDD2 protein expression in association with breast cancer samples negative for progesterone receptor (p = 0.015). Moreover, protein expression analysis corroborated the quantitative RT-PCR results, indicating that breast primary tumors belonging to patients with a more disseminated disease expressed significantly increased levels of RHBDD2 protein compared with less disseminated tumors (p = 0.01).

Breast cancer biomarker discovery in the functional genomic age: a systematic review of 42 gene expression signatures

In this review we provide a systematic analysis of transcriptomic signatures derived from 42 breast cancer gene expression studies, in an effort to identify the most relevant breast cancer biomarkers using a meta-analysis method. Meta-data revealed a set of 117 genes that were the most commonly affected ranging from 12% to 36% of overlap among breast cancer gene expression studies. Data mining analysis of transcripts and protein-protein interactions of these commonly modulated genes indicate three functional modules significantly affected among signatures, one module related with the response to steroid hormone stimulus, and two modules related to the cell cycle. Analysis of a publicly available gene expression data showed that the obtained meta-signature is capable of predicting overall survival (P < 0.0001) and relapse-free survival (P < 0.0001) in patients with early-stage breast carcinomas. In addition, the identified meta-signature improves breast cancer patient stratification independently of traditional prognostic factors in a multivariate Cox proportional-hazards analysis.

MUC1 oncogene amplification correlates with protein overexpression in invasive breast carcinoma cells

The MUC1 gene is aberrantly overexpressed in approximately 90% of human breast cancers. Several studies have shown that MUC1 overexpression is due to transcriptional regulatory events. However, the importance of gene amplification as a mechanism leading to the increase of MUC1 expression in breast cancer has been poorly characterized. The aim of this study was to evaluate the role of MUC1 gene amplification and protein expression in human breast cancer development. By means of real-time quantitative polymerase chain reaction and immunohistochemical methods, 83 breast tissue samples were analyzed for MUC1 gene amplification and protein expression. This analysis showed MUC1 genomic amplification and a positive association with the histopathological group in 12% (1 out of 8) of benign lesions and 38% (23 out of 60) of primary invasive breast carcinoma samples (P = 0.004). Array-comparative genomic hybridization meta-analysis of 886 primary invasive breast carcinomas obtained from 22 studies showed MUC1 genomic gain in 43.7% (387 out of 886) of the samples. Moreover, we identified a highly statistical significant association between MUC1 gene amplification and MUC1 protein expression assessed by immunohistochemistry and Western blot test (P < 0.0001). In conclusion, this study demonstrated that MUC1 copy number increases from normal breast tissue to primary invasive breast carcinomas in correlation with MUC1 protein expression.

Rhomboid domain containing 2 (RHBDD2): a novel cancer-related gene over-expressed in breast cancer

In the course of breast cancer global gene expression studies, we identified an uncharacterized gene known as RHBDD2 (Rhomboid domain containing 2) to be markedly over-expressed in primary tumors from patients with recurrent disease. In this study, we identified RHBDD2 mRNA and protein expression significantly elevated in breast carcinomas compared with normal breast samples as analyzed by SAGE (n=46) and immunohistochemistry (n=213). Interestingly, specimens displaying RHBDD2 over-expression were predominantly advanced stage III breast carcinomas (p=0.001). Western-blot, RT-PCR and cDNA sequencing analyses allowed us to identify two RHBDD2 alternatively spliced mRNA isoforms expressed in breast cancer cell lines. We further investigated the occurrence and frequency of gene amplification and over-expression affecting RHBDD2 in 131 breast samples. RHBDD2 gene amplification was detected in 21% of 98 invasive breast carcinomas analyzed. However, no RHBDD2 amplification was detected in normal breast tissues (n=17) or breast benign lesions (n=16) (p=0.014). Interestingly, siRNA-mediated silencing of RHBDD2 expression results in a decrease of MCF7 breast cancer cells proliferation compared with the corresponding controls (p=0.001). In addition, analysis of publicly available gene expression data showed a strong association between high RHBDD2 expression and decreased overall survival (p=0.0023), relapse-free survival (p=0.0013), and metastasis-free interval (p=0.006) in patients with primary ER-negative breast carcinomas. In conclusion, our findings suggest that RHBDD2 over-expression behaves as an indicator of poor prognosis and may play a role facilitating breast cancer progression.

Herpes simplex virus and human papillomavirus infection in cervical disease in Argentine women

The aim of the present study was to determine that prevalence of herpes simplex virus (HSV) type 1 and 2 in cervical samples from Argentine women and to assess the role of HSV-2 in cervical cancer. A sample of 79 normal and 200 neoplastic cervical tissues (35 invasive cervical carcinomas, 75 high-grade squamous intraepithelial lesions, 79 low-grade squamous intraepithelial lesions and 11 abnormal squamous cells of undermined significance) was analyzed for herpes simplex and human papillomavirus DNA using the polymerase chain reaction method. Viral genotyping was performed by single strand conformation polymorphisms and restriction fragment length polymorphisms. The overall prevalence of HSV was 21.5% in controls and 29% in cases. Among women with normal cytology, herpes simplex prevalence in HPV positive (20.8%) women was approximately the same as in negative (21.8%) women. HPV- and age- adjusted ORs of high-grade squamous intraepithelial lesions and invasive cervical carcinomas for HSV-2 were 1.4 (p = 0.6) and 1.6 (p = 0.5), respectively. The obtained results indicated that herpes simplex virus may not be involved in cervical cancer development. Future investigations are needed to provided conclusive evidence on the role of this pathogen in cervical cancer.

Analysis of adenocarcinoma of the colon and rectum: detection of human papillomavirus (HPV) DNA by polymerase chain reaction

OBJECTIVE

The aim of the present work was to evaluate the presence of human papillomavirus genotypes in malignant and normal mucosa of the colon and rectum in order to determine if a relationship exists between HPV infection and colon neoplasms.

MATERIALS AND METHODS

Thirty normal colon tissues and 54 sporadic adenocarcinomas were screened for HPV positivity using nested-PCR. Detection of viral types 6, 11, 16, 18, 33, 34 and 51 was performed by the LIS-SSCP (Low Ionic Strength-Single Strand Conformational Polymorphism) procedure.

RESULTS

Significant differences in high risk HPV infection were found between normal samples and adenocarcinomas (P < 0.001). Among the cases, an inverse association between HPV infection and Dukes staging was also found (P = 0.020). Finally, there was no significant association between HPV and some classical clinicopathological features, although a gradient of infection form rectum to cecum was evident.

CONCLUSION

The present study demonstrates that HPV may infect the glandular mucosa of the colon and suggests a possible association between HPV and colorectal cancer.

Association between copper deficiency and DNA damage in cattle

Cattle hypocuprosis is the second most widespread mineral deficiency affecting grazing cattle. The consequences of hypocuprosis include a failure of copper metalloenzymes, many of which form part of the antioxidant defence system. This work focuses on the association between copper (Cu) plasma concentration and DNA damage in Aberdeen Angus cattle. Two-hundred and ninety-nine heparinized blood samples from 2-year-old Aberdeen Angus cows were obtained from different farms located in the Salado River basin, Argentina. Plasma copper level analysis was carried out in whole samples, while cytogenetic analysis and single cell gel electrophoresis assay (comet assay) were carried out in 82 and 217 samples, respectively. Cytogenetic analysis showed a significant increase in the frequency of abnormal metaphases in moderate/severe hypocupremic groups (groups B and C) in relation to the normocupremic group (group A) (4.5 and 1.5 abnormal metaphases/100 cells, respectively, P < 0.01). The Spearman correlation test showed a negative association between cupremic values and the yield of chromosomal aberrations (r = -0.708, P < 0.0001). In the comet assay greater migration was observed in cells from the hypocupremic group, from a median of 54 in the severe hypocupremic group to 31 in the normocupremic group (P < 0.01). Accordingly, the Spearman correlation test showed a significant positive relationship between copper levels and cells without DNA migration and a significant negative relationship between copper levels and cells with a tiny tail (P < 0.0001 in both cases). The results obtained show that hypocupremia in cattle is associated with an increase in the frequency of chromosomal aberrations as well as in DNA migration as assessed by the comet assay. Whereas the comet assay could differentiate copper plasma level groups, chromosomal aberrations only detected differences between normal and hypocupremic animals. The increase of DNA damage found in hypocupremic animals could be explained by higher oxidative stress suffered by these animals.

[Human papillomavirus genotype distribution in cervical infections among woman in La Plata, Argentina]

Genital infection with human papillomavirus (HPV) is one of the most common sexually transmitted viral diseases. High risk HPV are now considered the main etiologic agent of cancer of the uterine cervix and their high-grade precursor lesions. The aim of the present study was to investigate the endemic HPV-genotype spectrum in a population of women from the city of La Plata, Argentina. With this purpose, 718 cervical scrapes or biopsies corresponding to 152 normal samples (Pap I/II), 84 samples classified as atypical squamous cells of undetermined significance (ASCUS), 100 condyloma, 279 low-grade squamous intraepithelial lesions (LGSIL), 82 high-grade squamous intraepithelial lesions (HGSIL), and 21 squamous cell carcinomas (SCC) were studied. The detection of HPV-DNA was performed by nested polymerase chain reaction, using My 09/11 and Gp 05/06. The viral genotypes were analyzed by single-stranded conformation polymorphisms, employing low ionic strength solution (LIS-SSCP). The overall prevalence of HPV infection was 75% in the analyzed population, with a frequency of 46% for normal cervix, 69% for ASCUS, 86% for condyloma, 80% for LGSIL, 98% for HGSIL and 100% for SCC. The most prevalent viral types were HPV 16 (35%), followed by HPV 6/11 (27% each one), HPV 33 (6%) and HPV 18 (5%). HPV 16 was the most prevalent viral type among women with LGSIL, HGSIL and SCC, representing 33%, 50% and 67% of the genital infections, respectively. HPV 6 and 11 were the most frequent viral types among samples classified as Pap I/II, ASCUS and condyloma. Women between 21 and 30 year old showed the highest prevalence of HPV positivity, compraising the 32.2% of total infections.

Association of human papillomavirus viral load with HPV16 and high-grade intraepithelial lesion

The aim of the present study was to evaluate the relationship between viral type and copy number of human papillomavirus (HPV) with respect to the grade of cervical disease, and also to identify the existence of an HPV type-dependent viral load effect. DNA from 275 exocervical specimens, previously evaluated for histologic diagnosis, were evaluated for HPV presence, HPV type, and viral load. Viral load determination was performed using the low stringency PCR method (LS-PCR). Significant differences were found between the samples infected with HPV16 with respect to the samples infected with other 'high-risk' viral types (HPV -18, -31, -33 or -51) and 'low-risk' types (P < 0.05). However, highly significant differences were found between the viral loads observed in the high-grade squamous intraepithelial lesions group and normal epithelium (OR = 8.53) or the low grade ones (OR = 3.10). Moreover, a high viral load was detected in the condyloma acuminatum group compared to the normal epithelia samples (p< 0.05). This work confirms the genotype-specific association of viral load to the presence of HPV16. Also, a trend to higher viral loads could be seen in the more compromised cervical lesions. An unexpected level of viral particles appeared associated to the condylomas. This fact could be explained by a productive infection with high levels of viral replication.

[Utilization of polymerase chain reaction for detection and genotyping of Helicobacter pylori in gastric biopsy using paraffin: a retrospective study]

BACKGROUND

Helicobacter pylori infection is presumed to be the major causal agent of chronic active gastritis in humans. The persistent infection with this pathogen would be an important factor in the pathogenesis of peptic ulcer and also gastric cancer.

METHODS

We investigated relationship between H. pylori characteristics in 42 patients with normal mucosa or gastritis with minor changes and 40 patients with mild and severe gastritis. Detection and typing of vacA and cagA genes were performed using a polymerase chain reaction method.

RESULTS

The analysis of vacA prevalence and the type (S1 or S2) showed non-significant differences between the two groups studied (p > 0.05). However, cagA analysis showed highly significant differences between the groups classified as normal tissue-weak gastritis and mild-severe gastritis (p < 0.0001; OR = 8.4; CI = 3.1-22.8).

CONCLUSIONS

cagA status is associated to the grade of gastritis, finding higher frequencies of H. pylori cagA+ in the moderate-severe gastritis group. These highly significant differences could make cagA status a genetic marker for disease progress.

c-myc gene amplification detected in preinvasive intraepithelial cervical lesions

The aim of the present work was to evaluate the c-myc gene amplification process in cervical samples and to analyze the relationship between the activation of this proto-oncogene and the cytologic and/or histologic status. Thirty-four normal cervical samples and 105 abnormal cervical tissue scrapes, previously used for PAP or histopathologic diagnosis, were analyzed for c-myc gene amplification. Detection of c-myc gene amplification was performed using a polymerase chain reaction (PCR)-based method known as target arbitrarily primed-PCR (TAP-PCR). For c-myc amplification, significant differences were found between normal samples and samples presenting different grades of lesions (P<0.001). A significant difference between high-grade squamous intraepithelial lesions (HG-SIL) and the other stages of cervical disease was also found (P<0.05). This study demonstrated that c-myc copy number increases according to the histologic grade of the lesion. These results could indicate that oncogene amplification takes place in preinvasive stages of cervical disease and could cooperate not only in tumor progression but also in cell transformation.

HLA-DQA1 allele typing by nonisotopic PCR-LIS-SSCP

In the present study we used a simple and reliable method for HLA-DQA1 allele typing based on the single-stranded conformation polymorphism (SSCP) properties of DNA molecules obtained by PCR. The technique consists of PCR amplification of a DNA fragment comprising the second exon of the HLA-DQA1 gene, amplicon denaturation using a low ionic strength solution (LIS), and electrophoresis on a small native polyacrylamide gel, followed by a rapid silver staining procedure. In order to validate the technique and to obtain the allele patterns for the DQA1 gene, 50 cervical samples were typed using this methodology and the commercial Amplitype HLA DQA1 Amplification and Typing kit. All the alleles detected with the kit were characterized by the LIS-SSCP approach. This procedure proved to be useful for population screening and typing of the DQA1 gene as well as for detecting new alleles or mutations in the donor-recipient molecular matching of HLA class II genes.

[Detection and genotyping of human papillomavirus (HPV) using PCR-LIS-SSCP]

This study describes a fast and simple method for human papillomavirus (HPV) typing based on the polymerase chain reaction (PCR) amplification of a portion of the viral genome and single strand conformation polymorphism using low ionic strength solutions (LIS-SSCP). PCR products were obtained using My09/My11 and Gp5/Gp6 primers in a nested reaction. The band patterns corresponded to the plasmid HPV clones from HPV-6, -11, -16, -18, -31, -33 and -34. The SSCP minigels were stained with SYBR-Green II. In order to determine diagnostic applicability, 100 cervical samples were studied comprising liquid cytology and paraffin embedded biopsies from patients showing squamous intraepithelial lesions (SILs). The SSCP patterns obtained from the clinical samples and the HPV clones were similar when the same type was present. Therefore, the methodology proved to be efficient and with high reproducibility for the detection and typing of HPV in clinical samples.

Association between activated K-ras and c-erbB-2 oncogenes with "high-risk" and "low-risk" human papilloma virus types in preinvasive cervical lesions

Clinical and epidemiological data have linked cervical cancer to the Human Papilloma Virus (HPV) infection. However, the presence of HPV infection alone is not enough to cause tumorigenesis, suggesting a role for additional host-cell genetic factors. The aim of the present work was to study the association of K-ras and c-erbB-2 mutations in cervical tissue samples with different grades of dysplasia and infected with HPV-6 ("low-risk" type) or HPV-16 and HPV-18 ("high-risk" types). Negative HPV-DNA samples were used as controls. The detection of K-ras and c-erbB-2 activation were performed by Artificial Refractory Mutation System (ARMS)-PCR and semiquantitative PCR, respectively. Statistical analysis showed a highly significant difference in K-ras codon 12 mutation frequency between high-risk and low-risk HPV-infected samples (p<0.05). On the other hand, amplification of the c-erbB-2 oncogene appeared associated to tissue samples infected with HPV-6 (p<0.003). Cervical carcinoma appears to arise from a series of well-characterized progressive histological changes, but the genetic alterations necessary for cervical tumorigenesis are not yet clear. These results raise the possibility for a role of certain proto-oncogenes and their activation in cervical neoplasia.