Simple virus-free mouse models of COVID-19 pathologies and oral therapeutic intervention

The paucity of preclinical models that recapitulate COVID-19 pathology without requiring SARS-COV-2 adaptation and humanized/transgenic mice limits research into new therapeutics against the frequently emerging variants-of-concern. We developed virus-free models by C57BL/6 mice receiving oropharyngeal instillations of a SARS-COV-2 ribo-oligonucleotide common in all variants or specific to Delta/Omicron variants, concurrently with low-dose bleomycin. Mice developed COVID-19-like lung pathologies including ground-glass opacities, interstitial fibrosis, congested alveoli, and became moribund. Lung tissues from these mice and bronchoalveolar lavage and lung tissues from patients with COVID-19 showed elevated levels of hyaluronic acid (HA), HA-family members, an inflammatory signature, and immune cell infiltration. 4-methylumbelliferone (4-MU), an oral drug for biliary-spasm treatment, inhibits HA-synthesis. At the human equivalent dose, 4-MU prevented/inhibited COVID-19-like pathologies and long-term morbidity; 4-MU and metabolites accumulated in mice lungs. Therefore, these versatile SARS-COV-2 ribo-oligonucleotide oropharyngeal models recapitulate COVID-19 pathology, with HA as its critical mediator and 4-MU as a potential therapeutic for COVID-19.

Indomethacin-induced oxidative stress enhances death receptor 5 signaling and sensitizes tumor cells to adoptive T-cell therapy

BACKGROUND

Adoptive cell therapy (ACT) using genetically modified T cells has evolved into a promising treatment option for patients with cancer. However, even for the best-studied and clinically validated CD19-targeted chimeric antigen receptor (CAR) T-cell therapy, many patients face the challenge of lack of response or occurrence of relapse. There is increasing need to improve the efficacy of ACT so that durable, curative outcomes can be achieved in a broad patient population.

METHODS

Here, we investigated the impact of indomethacin (indo), a non-steroidal anti-inflammatory drug (NSAID), on the efficacy of ACT in multiple preclinical models. Mice with established B-cell lymphoma received various combinations of preconditioning chemotherapy, infusion of suboptimal dose of tumor-reactive T cells, and indo administration. Donor T cells used in the ACT models included CD4+ T cells expressing a tumor-specific T cell receptor (TCR) and T cells engineered to express CD19CAR. Mice were monitored for tumor growth and survival. The effects of indo on donor T cell phenotype and function were evaluated. The molecular mechanisms by which indo may influence the outcome of ACT were investigated.

RESULTS

ACT coupled with indo administration led to improved tumor growth control and prolonged mouse survival. Indo did not affect the activation status and tumor infiltration of the donor T cells. Moreover, the beneficial effect of indo in ACT did not rely on its inhibitory effect on the immunosuppressive cyclooxygenase 2 (COX2)/prostaglandin E2 (PGE2) axis. Instead, indo-induced oxidative stress boosted the expression of death receptor 5 (DR5) in tumor cells, rendering them susceptible to donor T cells expressing TNF-related apoptosis-inducing ligand (TRAIL). Furthermore, the ACT-potentiating effect of indo was diminished against DR5-deficient tumors, but was amplified by donor T cells engineered to overexpress TRAIL.

CONCLUSION

Our results demonstrate that the pro-oxidative property of indo can be exploited to enhance death receptor signaling in cancer cells, providing rationale for combining indo with genetically modified T cells to intensify tumor cell killing through the TRAIL-DR5 axis. These findings implicate indo administration, and potentially similar use of other NSAIDs, as a readily applicable and cost-effective approach to augment the efficacy of ACT.

Quantification by Ultrafiltration and Immunofixation Electrophoresis Testing for Monoclonal Serum Free Light Chains

OBJECTIVE

Measurement of monoclonal immunoglobulins is a reliable estimate of the plasma cell tumor mass. About 15% of plasma cell myelomas secrete light chains only. The concentration of serum free light chains is insufficient evidence of the monoclonal light chain burden. A sensitive quantitative estimate of serum free monoclonal light chains could be useful for monitoring patients with light chain myeloma. We describe such an assay that does not require mass-spectrometry equipment or expertise.

METHODS

Serum specimens from patients with known light chain myelomas and controls were subjected to ultrafiltration through a membrane with pore size of 50 kDa. The filtrate was concentrated and tested by immunofixation electrophoresis. The relative area under the monoclonal peak, compared to that of the total involved light chain composition, was estimated by densitometric scanning of immunofixation gels. The proportion of the area occupied by the monoclonal peak in representative densitometric scans was used to arrive at the total serum concentration of the monoclonal serum free light chains.

RESULTS

Using an ultracentrifugation and concentration process, monoclonal serum free light chains were detectable, along with polyclonal light chains, in all 10 patients with active light chain myelomas. Monoclonal light chains were identified in serum specimens that did not reveal monoclonal light chains by conventional immunofixation electrophoresis. The limit of detection by this method was 1.0 mg/L of monoclonal serum free light chains.

CONCLUSION

The method described here is simple enough to be implemented in academic medical center clinical laboratories and does not require special reagents, equipment, or expertise. Even though urine examination is the preferred method for the diagnosis of light chain plasma cell myelomas, measurement of the concentration of serum free light chains provides a convenient, albeit inadequate, way to monitor the course of disease. The method described here allows effective electrophoretic differentiation of monoclonal serum free light chain from polyclonal serum free light chains and provides a quantitation of the monoclonal serum free light chains in monitoring light chain monoclonal gammopathies.

Chemoenzymatic modular assembly of O-GalNAc glycans for functional glycomics

O-GalNAc glycans (or mucin O-glycans) play pivotal roles in diverse biological and pathological processes, including tumor growth and progression. Structurally defined O-GalNAc glycans are essential for functional studies but synthetic challenges and their inherent structural diversity and complexity have limited access to these compounds. Herein, we report an efficient and robust chemoenzymatic modular assembly (CEMA) strategy to construct structurally diverse O-GalNAc glycans. The key to this strategy is the convergent assembly of O-GalNAc cores 1-4 and 6 from three chemical building blocks, followed by enzymatic diversification of the cores by 13 well-tailored enzyme modules. A total of 83 O-GalNAc glycans presenting various natural glycan epitopes are obtained and used to generate a unique synthetic mucin O-glycan microarray. Binding specificities of glycan-binding proteins (GBPs) including plant lectins and selected anti-glycan antibodies towards these O-GalNAc glycans are revealed by this microarray, promoting their applicability in functional O-glycomics. Serum samples from colorectal cancer patients and healthy controls are assayed using the array reveal higher bindings towards less common cores 3, 4, and 6 than abundant cores 1 and 2, providing insights into O-GalNAc glycan structure-activity relationships.

Comparative analysis of transcriptomic profile, histology, and IDH mutation for classification of gliomas

Gliomas are currently classified through integration of histology and mutation information, with new developments in DNA methylation classification. However, discrepancies exist amongst the major classification methods. This study sought to compare transcriptome-based classification to the established methods. RNAseq and microarray data were obtained for 1032 gliomas from the TCGA and 395 gliomas from REMBRANDT. Data were analyzed using unsupervised and supervised learning and other statistical methods. Global transcriptomic profiles defined four transcriptomic glioma subgroups with 91.4% concordance with the WHO-defined mutation subtypes. Using these subgroups, 168 genes were selected for the development of 1000 linear support vector classifiers (LSVC). Based on plurality voting of 1000 LSVC, the final ensemble classifier confidently classified all but 17 TCGA gliomas to one of the four transcriptomic profile (TP) groups. The classifier was validated using a gene expression microarray dataset. TP1 cases include IDHwt, glioblastoma high immune infiltration and cellular proliferation and poor survival prognosis. TP2a is characterized as IDHmut-codel, oligodendrogliomas with high tumor purity. TP2b tissue is mostly composed of neurons and few infiltrating malignant cells. TP3 exhibit increased NOTCH signaling, are astrocytoma and IDHmut-non-codel. TP groups are highly concordant with both WHO integrated histology and mutation classification as well as methylation-based classification of gliomas. Transcriptomic profiling provides a robust and objective method to classify gliomas with high agreement to the current WHO guidelines and may provide additional survival prediction to the current methods.

Promotion of epithelial hyperplasia by interleukin-8-CXCR axis in human prostate

BACKGROUND

The clinical manifestation of benign prostatic hyperplasia (BPH) is causally linked to the inflammatory microenvironment and proliferation of epithelial and stromal cells in the prostate transitional zone. The CXC-chemokine interleukin-8 (IL-8) contributes to inflammation. We evaluated the expression of inflammatory cytokines in clinical specimens, primary cultures, and prostatic lineage cell lines. We investigated whether IL-8 via its receptor system (IL-8 axis) promotes BPH.

METHODS

The messenger RNA and protein expression of chemokines, including components of the IL-8 axis, were measured in normal prostate (NP; n = 7) and BPH (n = 21), urine (n = 24) specimens, primary cultures, prostatic lineage epithelial cell lines (NHPrE1, BHPrE1, BPH-1), and normal prostate cells (RWPE-1). The functional role of the IL-8 axis in prostate epithelial cell growth was evaluated by CRISPR/Cas9 gene editing. The effect of a combination with two natural compounds, oleanolic acid (OA) and ursolic acid (UA), was evaluated on the expression of the IL-8 axis and epithelial cell growth.

RESULTS

Among the 19 inflammatory chemokines and chemokine receptors we analyzed, levels of IL-8 and its receptors (CXCR1, CXCR2), as well as, of CXCR7, a receptor for CXCL12, were 5- to 25-fold elevated in BPH tissues when compared to NP tissues (P ≤ .001). Urinary IL-8 levels were threefold to sixfold elevated in BPH patients, but not in asymptomatic males and females with lower urinary tract symptoms (P ≤ .004). The expression of the IL-8 axis components was confined to the prostate luminal epithelial cells in both normal and BPH tissues. However, these components were elevated in BPH-1 and primary explant cultures as compared to RWPE-1, NHPrE1, and BHPrE1 cells. Knockout of CXCR7 reduced IL-8, and CXCR1 expression by 4- to 10-fold and caused greater than or equal to 50% growth inhibition in BPH-1 cells. Low-dose OA + UA combination synergistically inhibited the growth of BPH-1 and BPH primary cultures. In the combination, the drug reduction indices for UA and OA were 16.4 and 7852, respectively, demonstrating that the combination was effective in inhibiting BPH-1 growth at significantly reduced doses of UA or OA alone.

CONCLUSION

The IL-8 axis is a promotor of BPH pathogenesis. Low-dose OA + UA combination inhibits BPH cell growth by inducing autophagy and reducing IL-8 axis expression in BPH-epithelial cells.

Abstract 1404: MicroRNA-mediated induction of neuroendocrine differentiation states in metastatic castration-resistant prostate cancer

While the widespread use of androgen receptor pathway inhibitors (APIs) such as enzalutamide has led to transformative impact in the management of metastatic castration-resistant prostate cancer (CRPC) patients, resistance is near-universal leading to significantly increased incidences of highly aggressive, therapy-induced neuroendocrine differentiation (NED). It has been realized that therapy-induced NED represents a continuum of treatment-induced changes at phenotypic and molecular level that involves a series of alterations at genetic, epigenetic, post-transcriptional, post-translational levels and changes in microenvironment. Though several recent studies identified key genomic and epigenomic alterations driving therapy-induced NED, the molecular pathogenesis is still not completely understood contributing to late diagnosis of the disease, poor prognosis and lack of effective therapies. The focused objective of our study was to systematically investigate the key microRNA (miRNAs) alterations that drive therapy-induced NED in PCa. We hypothesized that this lineage switch is associated with significant alterations to the miRNAome, that in turn, drives change in cellular gene expression patterns towards NE states. We tested our hypothesis by performing small RNA-NGS in a clinical cohort of patient samples, patient-derived xenograft and cellular models. We identify for the first time that a characteristic set of miRNA alterations promote plasticity of prostate tumors to NE states. Importantly, we identify downregulation of miR-363 as a prominent molecular alteration underlying PCa NED. To examine the functional role of miR-363, we knocked down its expression in CRPC cell lines C42B and LNCaP followed by functional assays. Decreased miR-363 expression resulted in increased clonogenicity potential and invasiveness of PCa cell lines as compared to control suggesting that miR-363 loss contributes to increased aggressiveness. Importantly, we found that miR-363 directly represses Aurora kinase A (AURKA), a prototypical kinase frequently amplified in NED. Correlation analyses in TCGA database of prostate adenocarcinomas (n=494) showed a significant inverse correlation between miR-363 expression and AURKA mRNA levels. In conclusion, our study identifies crucial molecular determinants of NED with potential clinical and transformative potential. Since AURKA inhibition is currently being examined as a therapeutic modality for NEPC, we propose augmentation of miR-363 levels to repress AURKA as a novel treatment option for therapy-induced NEPC.

Citation Format: Divya Bhagirath, Michael Liston, Byron Lui, Dat My To, Thao Ly Yang, Laura Z. Tabatabai, Nikhil Patel, Roni Bollag, Adam Olshen, Sharanjot Saini. MicroRNA-mediated induction of neuroendocrine differentiation states in metastatic castration-resistant prostate cancer [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 1404.

Abstract 282: MicroRNAs located at chromosome 8p21-22 region as novel factors underlying racial disparities in prostate cancer aggressiveness

The mechanistic basis of racial disparities in prostate cancer (PCa) aggressiveness between African American (AA) and Caucasian (CA) men are not yet fully understood. Further, molecular biomarkers to predict aggressive disease at its onset have been studied primarily in CAs, the relevance of these biomarkers to AAs are largely unknown. We propose a novel, paradigm-shifting hypothesis that expression of microRNA (miRNA) genes-miR-3622a and miR-383-located within frequently deleted chr8p21-22 region constitute important molecular factors contributing to racial disparities in PCa aggressiveness in AA vs CA men. Chromosome 8p deletions are a frequent alteration of PCa genome, with a common region of loss of heterozygosity at the chr8p21-22 locus. We previously showed that this region is associated with a set of tumor suppressive miRNAs (miR-3622a/b, -383, -4288) that are downregulated in PCa with important causal roles in tumor progression, recurrence and metastasis. Chr8p deletions increase significantly with tumor grade and are associated with poor prognosis. These deletions are well studied in CA men. However, there have been conflicting reports on frequency of chr8p deletions in AA men. In view of these conflicting studies and in light of our paradigm-shifting studies establishing the link between chr8p deletions and loss of miRNA genes in this region, we examined the expression of these miRNAs in AA vs CA clinical PCa tissues. We found that miR-3622a and miR-383 expression is significantly lower in AA men as compared to age, tumor stage and grade matched CAs. To examine if these miRNAs constitute causal factors contributing to PCa racial disparities, we overexpressed miR-3622a/miR-383/control miR in AA and CA PCa cell lines followed by functional assays. We found that these miRNAs exert more prominent effects on cellular proliferation and apoptosis in AA cell lines. To understand molecular mechanisms contributing to disparate functional effects of these miRNAs in AA vs CA cell lines, we examined potential miRNA target genes and found that miR-3622a regulates PCa stem cell marker, CD44 while miR-383 represses LEF1 and ZEB1 in a race-specific manner. Further, we determined the mechanistic basis of differential expression of miR-3622a in AAs vs CAs by examining copy number alterations (CNAs) and methylation at this locus using PCa clinical samples. Our analyses showed that while this locus is genomically altered at a lower frequency in AAs, significantly increased frequency of miRNA promoter hypermethylation was found in AAs as compared to CAs. In conclusion, our data suggests that miRNAs located in frequently deleted chr8p21-22 region constitute important causal factors contributing to racial disparities in PCa aggressiveness and clinical outcomes and are potential biomarkers to predict PCa aggressiveness and tumor recurrence in AA men.

Citation Format: Divya Bhagirath, Nikhil Patel, Santu Ghosh, Roni Bollag, Sharanjot Saini. MicroRNAs located at chromosome 8p21-22 region as novel factors underlying racial disparities in prostate cancer aggressiveness [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 282.

Identifying Sialylation Linkages at the Glycopeptide Level by Glycosyltransferase Labeling Assisted Mass Spectrometry (GLAMS)

Precise assignment of sialylation linkages at the glycopeptide level is of importance in bottom-up glycoproteomics and an indispensable step to understand the function of glycoproteins in pathogen-host interactions and cancer progression. Even though some efforts have been dedicated to the discrimination of α2,3/α2,6-sialylated isomers, unambiguous identification of sialoglycopeptide isomers is still needed. Herein, we developed an innovative glycosyltransferase labeling assisted mass spectrometry (GLAMS) strategy. After specific enzymatic labeling, oxonium ions from higher-energy C-trap dissociation (HCD) fragmentation of α2,3-sailoglycopeptides then generate unique reporters to distinctly differentiate those of α2,6-sailoglycopeptide isomers. With this strategy, a total of 1236 linkage-specific sialoglycopeptides were successfully identified from 161 glycoproteins in human serum.

DNA methylation patterns in bladder tumors of African American patients point to distinct alterations in xenobiotic metabolism

Racial/ethnic disparities have a significant impact on bladder cancer outcomes with African American patients demonstrating inferior survival over European-American patients. We hypothesized that epigenetic difference in methylation of tumor DNA is an underlying cause of this survival health disparity. We analyzed bladder tumors from African American and European-American patients using reduced representation bisulfite sequencing (RRBS) to annotate differentially methylated DNA regions. Liquid chromatography-mass spectrometry (LC-MS/MS) based metabolomics and flux studies were performed to examine metabolic pathways that showed significant association to the discovered DNA methylation patterns. RRBS analysis showed frequent hypermethylated CpG islands in African American patients. Further analysis showed that these hypermethylated CpG islands in patients are commonly located in the promoter regions of xenobiotic enzymes that are involved in bladder cancer progression. On follow-up, LC-MS/MS revealed accumulation of glucuronic acid, S-adenosylhomocysteine, and a decrease in S-adenosylmethionine, corroborating findings from the RRBS and mRNA expression analysis indicating increased glucuronidation and methylation capacities in African American patients. Flux analysis experiments with 13C-labeled glucose in cultured African American bladder cancer cells confirmed these findings. Collectively, our studies revealed robust differences in methylation-related metabolism and expression of enzymes regulating xenobiotic metabolism in African American patients indicate that race/ethnic differences in tumor biology may exist in bladder cancer.

Abstract 2217: Serum metabolic profiling identified a distinct metabolic signature in bladder cancer smokers: A key metabolic enzymes associated with patient survival

Urinary bladder cancer (BLCA) is the 9th most common malignant disease and the 13th most common cause of cancer death worldwide. Occupational exposure to carcinogens has been long associated with increased BLCA risk. Tobacco smoke contains more than 60 carcinogens causing at least 18 different types of cancer including BLCA. Reliable biomarkers for accurately predicting survival in Bladdder cancer (BLCA) smokers is lacking due to complex genomic and transcriptomic heterogeneities associated with the disease. We performed liquid chromatography-mass spectrometry (LC-MS) based targeted metabolomic analysis for >300 metabolites in serum obtained from two independent cohorts of BLCA never smokers, smokers, healthy smokers, and healthy never smokers. 40 metabolites (FDR <0.25) were identified to be differential between BLCA never smokers and smokers. Increased abundance of amino acids (tyrosine, phenylalanine, proline, serine, valine, isoleucine, glycine, asparagine) and taurine levels were observed in BLCA smokers. Integration of differential metabolomic gene signature and transcriptomics from TCGA cohort resulted in intersecting 17 gene signature that showed significant correlation with patient survival in BLCA smokers. Importantly Catechol-O-Methyltransferase (COMT), Iodotyrosine Deiodinase (IYD), and Tubulin Tyrosine Ligase (TTL) showed a significant association with patient survival in publicly available BLCA smokers datasets and did not have any clinical association in never smokers.

Note: This abstract was not presented at the meeting.

Citation Format: Chandra S. Amara, Chandrashekar R. Ambati, Venkatrao Vantaku, Piyarathna W b Danthasinghe, Sri Ramya Donepudi, Shiva S. Ravi, James M. Arnold, Vasantha Putluri, Gurkamal Chatta, Khurshid A. Guru, Hoda Badr, Martha K. Terris, Roni Bollag, Arun Sreekumar, Andrea B. Apolo, Nagireddy Putluri. Serum metabolic profiling identified a distinct metabolic signature in bladder cancer smokers: A key metabolic enzymes associated with patient survival [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 2217.

Abstract 5230: Modulation of SF3B1 causes global intron retention and downregulation of the B-cell receptor pathway in chronic lymphocytic leukemia

Splicing factor SF3B1 is frequently mutated in chronic lymphocytic leukemia (CLL) patients and has been suggested as a potential therapeutic target. In this study, we demonstrated that SF3B1 modulator sudemycin D6 (SD6) effectively inhibits cell growth and induces apoptosis in CLL cells. RNA sequencing analysis revealed significant increases in global intron retention in SD6-treated CLL cells. Pathway analysis of the genes associated with increased intron retention suggested that B-cell receptor (BCR) and PI3K signaling pathways were among the most important pathways being affected by SD6. The increases in intron retention were inversely correlated with decreases in mRNA and protein levels of the affected BCR/PI3K pathway molecules including BLNK, BTK, AKT, PLCγ2, and PI3Kδ. SD6 treatment also induced a time-dependent exon-skipping event in MCL-1 mRNA and resulted in significant down-regulation of another anti-apoptotic gene TRAF1, thus collectively contributing to the SD6-induced apoptosis. Furthermore, SD6 treatment can overcome the pro-survival and pro-growth signals and synergize with established CLL therapies ibrutinib, idelalisib, and venetoclax to induce apoptosis in primary CLL cells co-cultured with bone marrow stromal cells and T-cell-derived cytokines. Finally, in vivo treatment with SD6 at 10mg/kg/day for 7 days significantly inhibited the growth of xenograft tumors that were established by subcutaneous inoculation of 5×106 MEC1 CLL cells into NOD mice. Collectively, these results provide a strong rationale for the future clinical development of spliceosome modulators and potential combination therapies for the treatment of CLL.

Citation Format: Qimei Han, Jianbo Wang, Austin Y. Shull, Fang Shi, Libin Deng, Jeong-Hyeon Choi, Eun-Jeong Park, Shuo Tu, Lirong Pei, Farrukh T. Awan, Roni Bollag, Locke J. Bryan, Hong-bo Xin, Chandraiah Lagisetti, Thomas R. Webb, Victor Jin, Huidong Shi. Modulation of SF3B1 causes global intron retention and downregulation of the B-cell receptor pathway in chronic lymphocytic leukemia [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 5230.

The co-chaperone UNC45A is essential for the expression of mitotic kinase NEK7 and tumorigenesis

Cumulative evidence suggests that the heat shock protein 90 (Hsp90) co-chaperone UNC-45 myosin chaperone A (UNC45A) contributes to tumorigenesis and that its expression in cancer cells correlates with proliferation and metastasis of solid tumors. However, the molecular mechanism by which UNC45A regulates cancer cell proliferation remains largely unknown. Here, using siRNA-mediated gene silencing and various human cells, we report that UNC45A is essential for breast cancer cell growth, but is dispensable for normal cell proliferation. Immunofluorescence microscopy, along with gene microarray and RT-quantitative PCR analyses, revealed that UNC45A localizes to the cancer cell nucleus, where it up-regulates the transcriptional activity of the glucocorticoid receptor and thereby promotes expression of the mitotic kinase NIMA-related kinase 7 (NEK7). We observed that UNC45A-deficient cancer cells exhibit extensive pericentrosomal material disorganization, as well as defects in centrosomal separation and mitotic chromosome alignment. Consequently, these cells stalled in metaphase and cytokinesis and ultimately underwent mitotic catastrophe, phenotypes that were rescued by heterologous NEK7 expression. Our results identify a key role for the co-chaperone UNC45A in cell proliferation and provide insight into the regulatory mechanism. We propose that UNC45A represents a promising new therapeutic target to inhibit cancer cell growth in solid tumor types.

Large-scale profiling of serum metabolites in African American and European American patients with bladder cancer reveals metabolic pathways associated with patient survival

BACKGROUND

African Americans (AAs) experience a disproportionally high rate of bladder cancer (BLCA) deaths even though their incidence rates are lower than those of other patient groups. Using a metabolomics approach, this study investigated how AA BLCA may differ molecularly from European Americans (EAs) BLCA, and it examined serum samples from patients with BLCA with the aim of identifying druggable metabolic pathways in AA patients.

METHODS

Targeted metabolomics was applied to measure more than 300 metabolites in serum samples from 2 independent cohorts of EA and AA patients with BLCA and healthy EA and AA controls via liquid chromatography-mass spectrometry, and this was followed by the identification of altered metabolic pathways with a focus on AA BLCA. A subset of the differential metabolites was validated via absolute quantification with the Biocrates AbsoluteIDQ p180 kit. The clinical significance of the findings was further examined in The Cancer Genomic Atlas BLCA data set.

RESULTS

Fifty-three metabolites, mainly related to amino acid, lipid, and nucleotide metabolism, were identified that showed significant differences in abundance between AA and EA BLCA. For example, the levels of taurine, glutamine, glutamate, aspartate, and serine were elevated in serum samples from AA patients versus EA patients. By mapping these metabolites to genes, this study identified significant relations with regulators of metabolism such as malic enzyme 3, prolyl 3-hydroxylase 2, and lysine demethylase 2A that predicted patient survival exclusively in AA patients with BLCA.

CONCLUSIONS

This metabolic profile of serum samples might be used to assess risk progression in AA BLCA. These first-in-field findings describe metabolic alterations in AA BLCA and emphasize a potential biological basis for BLCA health disparities.

Genomic analysis of racial differences in triple negative breast cancer

Triple negative breast cancer (TNBC) is more prevalent in African Americans (AAs), has a more aggressive clinical course including a higher mortality rate and an increased occurrence of metastases. This study was designed to determine if racial differences at the molecular level might explain the more aggressive phenotype in AAs. Mutation profiling, was performed on 51 AA and 77 CA tumor/ normal pairs. Transcript expression analysis was performed on 35AA and 37CA. Genes with high frequency mutation rates such as MUC4 and TP53 were common to both racial populations, however genes that were less frequently mutated differed between the races suggesting that those cause the more aggressive nature of TNBC in AA women. JAK-Stat and HER2 signaling were unique to the AA and PTEN and mTOR were unique to the CA profiles. Many pathways identified by the mutational profiles were predicted to be down-regulated by the transcript expression profiles.

Abstract 5666: Octaplex spectral imaging of non-small cell lung cancer (NSCLC): In-depth insights into lung cancer immune micro-environment

Introduction: Lung cancer continues to be the lead cause of death among all cancer types. Checkpoint Inhibitors (CPI) showed great promise in curing or prolonging survival in various cancer types including advanced NSCLC, and others (HNSCC, RCC, Melanoma). The key limiting steps to such success is to find the right target population, minimize toxicities and better understand resistance mechanisms. Despite recent discoveries (1), there continues to be a huge need for development of better predictive biomarkers. Combining immunology and pathology knowledge will help guide the field of immune-oncology. Our group is interested in more in-depth anatomic dissection of immune TME (iTME).

Methods: To better understand the iTME in NSCLC and get deeper insight into the interaction of immune infiltrate with tumor cells, we successfully performed 8-color multispectral imaging (MSI) on 7 available cases of early stage NSCLC at Georgia Cancer Center. All 7 cases were successfully stained for CD4, CD8, FOXP3, PDL1, Ki67, CD68, CK, and DAPI. The regions of interest were identified by a research pathologist and images were captured using the Vectra 3 system (Perkinelmer).

Results: Octaplex staining was successful in this pilot study. All cases had significant immune infiltrate consistent of T and B lymphocytes as well as Tregs and CD68+ macrophages. The distribution of most infiltrates took a network like picture highlighting the piecemeal approach of immune infiltrate to attack cancer cells. In many instances, the infiltrate traces the tumoral capillary network. None of the cases followed the patterns described previously (2), but ather a mixture of these morphologies. Areas highly expressing PD-L1 tended to be devoid of Tcells but highly expressed on the edges of highly infiltrated areas. Tumor cells cruise through iTME by forming small agglomerates of cells or elongated shaped individual cells. Surprisingly CD4:CD8 ratio was inversely related to tumor differentiation with low ratio in poorly differentiated, solid patterns. In addition, immune infiltrates seem to be locked within areas where PD-L1 is highly expressed by tumor or its vascular network.

Conclusion: This pilot study provides insights from guided pathology. Under sampling is a major problem in studies and might lead to false conclusions. New insights into immune resistance through “Egress Lock” is a potential resistance mechanism to immune therapies. Type of infiltrate and its behavior still need further in-depth examination.

References:

1. Patel, S. P., & Kurzrock, R. (2015). PD-L1 expression as a predictive biomarker in cancer immunotherapy. Molecular cancer therapeutics, 14(4), 847-856.

2. Fridman, W. H., Galon, J., Pagès, F., Tartour, E., Sautès-Fridman, C., & Kroemer, G. (2011). Prognostic and predictive impact of intra-and peritumoral immune infiltrates. Cancer research, 71(17), 5601-5605.

Citation Format: Houssein Abdul Sater, Scott Allen, Chetan Pundkar, Kimya Jones, Nikhil Patel, Ravi Kolhe, Roni Bollag, Carsten Schroder. Octaplex spectral imaging of non-small cell lung cancer (NSCLC): In-depth insights into lung cancer immune micro-environment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5666.

Abstract LB-282: Dynamic regulation of CD73 expression in cancer associated fibroblasts enforces immunosuppression via a feedforward adenosinergic pathway

CD73 is the major extracellular adenosine-generating ecto-5'-nucleotidase (Nt5e) that metabolizes extracellular (e) AMP and generates immunosuppressive adenosine (eADO). Elevated CD73 expression is often exploited by tumors and other cellular constituents of the tumor microenvironment (TME) as a mechanism of immune evasion. Clinically, a high level of CD73 expression in the tumor microenvironment (TME) is linked to poor prognosis. Experimental evidence also demonstrates that host CD73 activity in both hematopoietic and non-hematopoietic compartments augments the suppressive milieu of the TME. Nevertheless, the identities of CD73-expressing non-hematopoietic cells and factors that regulate CD73 activity of these cells have yet to be clearly defined. Our recent results unravel that cancer associated fibroblasts (CAFs) constitute a crucial non-hematopoietic CD73hi compartment in the TME of human colorectal cancer (CRC) and murine MC38 CRC and EG7 lymphoma ectopic models. Strikingly, the CD73 expression profile among cohorts of published human CRC and breast cancer patient data sets confirmed its significant positive association with that of CAF-related markers, both of which are negatively correlated with poor survival. Cellular and transcriptomic analyses of CAFs in the EG7 TME reveal that CD73 expression in CAFs increases progressively during tumor progression, associated with elevated tissue hypoxia. Mechanistically, we demonstrate that the progressive elevation of CD73 expression in CAFs during tumor progression is caused by elevated eADO in the TME, which is resulted by the hypoxia/necrosis-associated eATP release. Furthermore, this eADO/adenosingeric pathway-induced CD73 upregulation in CAFs is mostly mediated by activation of A2BR and downstream MAPK signaling, which exacerbates eADO accumulation and serves as a feedforward loop of re-enforcing the immunosuppressive TME. Our study demonstrated that clinically and experimentally, high level of CD73 expression in CAFs represents another crucial immune checkpoint in the TME. Targeted inactivation or blockade of A2BR signaling may serve as a new strategy to prevent or alleviate the initiation of the eADO-CD73-associated amplification of immunosuppression in the TME, thereby improving the outcome of immunotherapy.

Citation Format: Miao Yu, Gang Guo, Lei Huang, Libin Deng, Roni Bollag, Andrew Mellor, Huidong Shi, Yan Cui. Dynamic regulation of CD73 expression in cancer associated fibroblasts enforces immunosuppression via a feedforward adenosinergic pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-282.

Comparing leukapheresis protocols for an AML patient with symptomatic leukostasis

BACKGROUND

Acute myeloid leukemia (AML) is a malignancy characterized by rapid clonal proliferation of myeloid precursors, which can result in hyperleukocytosis. Leukapheresis can be used to rapidly reduce the white blood cell count (WBC). However, the only FDA cleared device for WBC depletion, the COBE Spectra, will no longer be supported by the manufacturer in 2017, and there are few studies comparing different methods of leukapheresis.

CASE REPORT

A 68-year-old African American female was admitted to the hospital for relapse of her AML. Laboratory data demonstrated a WBC count of 291 600/μL and flow cytometry of the peripheral blood demonstrated 85% myeloid blasts. Leukapheresis was ordered to help treat the leukostasis.

METHODS

Three different apheresis protocols were used to achieve cytoreduction: Spectra Optia mononuclear collection (MNC) protocol, Spectra Optia granulocyte collection (PMN) protocol, and Therakos CELLEX buffy coat collection without return. Due to different inlet flow rates, the procedures were evaluated based on the number of WBCs collected and volume of blood processed (VBP).

RESULTS

The Spectra Optia PMN collected the most WBCs and collected nearly as many WBCs per VBP as the Therakos CELLEX, which had the highest value.

CONCLUSION

To our knowledge, we are reporting the first use of Therakos CELLEX and Spectra Optia PMN protocol for WBC depletion. While the Spectra Optia granulocyte protocol showed the best performance for this AML patient, further studies will be needed to compare the Spectra Optia PMN protocol to the MNC protocol for AML patients.

Fibroblastic reticular cells of the lymphoid tissues modulate T cell activation threshold during homeostasis via hyperactive cyclooxygenase-2/prostaglandin E2 axis

Fibroblastic reticular cells (FRCs) in the T cell zone of lymph nodes (LNs) are pivotal for T cell survival, mobility, and peripheral tolerance. Here, we demonstrate that during homeostasis, FRCs also suppress T cell activation via producing high level of prostaglandin E₂ (PGE₂) due to their thousands-fold higher cyclooxygenase-2 (COX-2) expression than immune cells. This hyperactive COX-2/PGE₂-induced suppression is evident during antigen-specific and non-antigen-specific activations. It is implicated as suppressed TCR-signaling cascades, reduced alterations in activation markers, and inhibited cytokine production of freshly isolated T cells or T cells co-cultured with FRCs compared with those cultured without FRCs. Different from T cell dysfunction, this FRC-mediated suppression is surmountable by enhancing the strength of stimulation and is reversible by COX-2 inhibitors. Furthermore, T cells in the FRC environment where Cox-2 is genetic inactivated are more sensitive and rapidly activated upon stimulations than those in WT environment. Significantly, FRCs of human lymphoid organs manifest similar COX-2/PGE₂ hyperactivity and T cell suppression. Together, this study identifies a previously unappreciated intrinsic mechanism of FRCs shared between mice and humans for suppressing T cell sensitivity to activation via PGE2, underscoring the importance of FRCs in shaping the suppressive milieu of lymphoid organs during homeostasis.

Fine needle aspiration cytology of an endotracheal mass: report of a case with an unusual presentation of anaplastic large cell lymphoma

BACKGROUND

Anaplastic large cell lymphoma (ALCL) is an uncommon hematolymphoid neoplasm characterized by malignant lymphocytes of T-cell phenotype. It usually affects young patients and may involve a variety of tissues and organs. We herein describe a case of ALCL that presented as an endotracheal mass with associated hilar lymphadenopathy. To the best of our knowledge this is the first case in the literature arising in the trachea. In this location the diagnosis of ALCL can be especially difficult as its pleomorphic cytomorphology mimics that of a carcinoma, which is a more typical neoplasm arising in the trachea.

CASE

A 26-year-old male presented with hemoptysis and paroxysmal chest pain. Imaging revealed an endotracheal mass and multiple lytic bone lesions. Fine needle aspiration biopsy of the endotracheal mass revealed discohesive malignant cells with abundant, pale cytoplasm and cerebriform, donut-shaped and horseshoe-shaped nuclei. Immunohistochemical studies confirmed the diagnosis of ALCL.

CONCLUSION

ALCL may have an unusual presentation and involve diverse sites, including the trachea. While its cytologic features are straightforward, a high index of suspicion is necessary to ensure accurate diagnosis when it presents in unusual locations.

The solitary long terminal repeats of ERV-9 endogenous retrovirus are conserved during primate evolution and possess enhancer activities in embryonic and hematopoietic cells

The solitary long terminal repeats (LTRs) of ERV-9 endogenous retrovirus contain the U3, R, and U5 regions but no internal viral genes. They are middle repetitive DNAs present at 2,000 to 4,000 copies in primate genomes. Sequence analyses of the 5" boundary area of the erythroid beta-globin locus control region (beta-LCR) and the intron of the embryonic axin gene show that a solitary ERV-9 LTR has been stably integrated in the respective loci for at least 15 million years in the higher primates from orangutan to human. Functional studies utilizing the green fluorescent protein (GFP) gene as the reporter in transfection experiments show that the U3 region of the LTRs possesses strong enhancer activity in embryonic cells of widely different tissue origins and in adult cells of blood lineages. In both the genomic LTRs of embryonic placental cells and erythroid K562 cells and transfected LTRs of recombinant GFP plasmids in K562 cells, the U3 enhancer activates synthesis of RNAs that are initiated from a specific site 25 bases downstream of the AATAAA (TATA) motif in the U3 promoter. A second AATAAA motif in the R region does not serve as the TATA box or as the polyadenylation signal. The LTR-initiated RNAs extend through the R and U5 regions into the downstream genomic DNA. The results suggest that the ERV-9 LTR-initiated transcription process may modulate transcription of the associated gene loci in embryonic and hematopoietic cells.

Identification of caveolin and caveolin-related proteins in the brain

Caveolae are 50-100 nm, nonclathrin-coated, flask-shaped plasma membrane microdomains that have been identified in most mammalian cell types, except lymphocytes and neurons. To date, multiple functions have been ascribed to caveolae, including the compartmentalization of lipid and protein components that function in transmembrane signaling events, biosynthetic transport functions, endocytosis, potocytosis, and transcytosis. Caveolin, a 21-24 kDa integral membrane protein, is the principal structural component of caveolae. We have initiated studies to examine the relationship of detergent-insoluble complexes identified in astrocytes to the caveolin-caveolae compartment detected in cells of peripheral tissues. Immunolocalization studies performed in astrocytes reveal caveolin immunoreactivity in regions that correlate well to the distribution of caveolae and caveolin determined in other cell types, and electron microscopic studies reveal multiple clusters of flask-shaped invaginations aligned along the plasma membrane. Immunoblot analyses demonstrate that detergent-insoluble complexes isolated from astrocytes are composed of caveolin-1alpha, an identification verified by Northern blot analyses and by the cloning of a cDNA using reverse transcriptase-PCR amplification from total astrocyte RNA. Using a full-length caveolin-1 probe, Northern blot analyses suggest that the expression of caveolin-1 may be regulated during brain development. Immunoblot analyses of detergent-insoluble complexes isolated from cerebral cortex and cerebellum identify two immunoreactive polypeptides with apparent molecular weight and isoelectric points appropriate for caveolin. The identification of caveolae microdomains and caveolin-1 in astrocytes and brain, as well as the apparent regulation of caveolin-1 expression during brain development, identifies a cell compartment not detected previously in brain.

Evolution of mouse T-box genes by tandem duplication and cluster dispersion

The T-box genes comprise an ancient family of putative transcription factors conserved across species as divergent as Mus musculus and Caenorhabditis elegans. All T-box gene products are characterized by a novel 174-186-amino acid DNA binding domain called the T-box that was first discovered in the polypeptide products of the mouse T locus and the Drosophila melanogaster optomotor-blind gene. Earlier studies allowed the identification of five mouse T-box genes, T, Tbx1-3, and Tbr1, that all map to different chromosomal locations and are expressed in unique temporal and spatial patterns during embryogenesis. Here, we report the discovery of three new members of the mouse T-box gene family, named Tbx4, Tbx5, and Tbx6. Two of these newly discovered genes, Tbx4 and Tbx5, were found to be tightly linked to previously identified T-box genes. Combined results from phylogenetic, linkage, and physical mapping studies provide a picture for the evolution of a T-box subfamily by unequal crossing over to form a two-gene cluster that was duplicated and dispersed to two chromosomal locations. This analysis suggests that Tbx4 and Tbx5 are cognate genes that diverged apart from a common ancestral gene during early vertebrate evolution.