Prevalence of viral DNA in high-grade serous epithelial ovarian cancer and correlation with clinical outcomes.

INTRODUCTION: Currently 11 infectious agents are classified as carcinogenic but the role of infectious agents on outcomes of epithelial ovarian cancer is largely unknown. OBJECTIVE: To explore the association between infectious agents and ovarian cancer, we investigated the prevalence of viral DNA in primary ovarian cancer tumors and its association with clinical outcomes. METHODS: Archived tumors from 98 patients diagnosed with high-grade serous epithelial ovarian cancer were collected between 1/1/1994 and 12/31/2010. After DNA extraction, Luminex technology was utilized to identify polymerase chain reaction-amplified viral DNA for 113 specific viruses. Demographic data and disease characteristics were summarized using descriptive statistics. We used logistic regression and Cox proportional hazards model to assess associations between tumor viral status and disease outcome and between tumor viral presence and overall survival (OS), respectively. RESULTS: Forty-six cases (45.9%) contained at least one virus. Six highly prevalent viruses were associated with clinical outcomes and considered viruses of interest (VOI; Epstein-Barr virus 1, Merkel cell polyomavirus, human herpes virus 6b, and human papillomaviruses 4, 16, and 23). Factors independently associated with OS were presence of VOI (HR 4.11, P = 0.0001) and platinum sensitivity (HR 0.21, P<0.0001). Median OS was significantly decreased when tumors showed VOI versus not having these viruses (22 vs 44 months, P<0.0001). Women <70 year old with VOI in tumors had significantly lower median OS versus age-matched women without VOI (20 vs 57 months, P = 0.0006); however, among women ≥70 years old, there was no difference in OS by tumor virus status. CONCLUSIONS: The presence of a VOI was significantly associated with a lower OS. These findings may have implications for clinical management of ovarian cancer but require additional studies.

Detectable Lipidomes and Metabolomes by Different Plasma Exosome Isolation Methods in Healthy Controls and Patients with Advanced Prostate and Lung Cancer.

Circulating exosomes in the blood are promising tools for biomarker discovery in cancer. Due to their heterogeneity, different isolation methods may enrich distinct exosome cargos generating different omic profiles. In this study, we evaluated the effects of plasma exosome isolation methods on detectable multi-omic profiles in patients with non-small cell lung cancer (NSCLC), castration-resistant prostate cancer (CRPC), and healthy controls, and developed an algorithm to quantify exosome enrichment. Plasma exosomes were isolated from CRPC (n = 10), NSCLC (n = 14), and healthy controls (n = 10) using three different methods: size exclusion chromatography (SEC), lectin binding, and T-cell immunoglobulin domain and mucin domain-containing protein 4 (TIM4) binding. Molecular profiles were determined by mass spectrometry of extracted exosome fractions. Enrichment analysis of uniquely detected molecules was performed for each method with MetaboAnalyst. The exosome enrichment index (EEI) scores methods based on top differential molecules between patient groups. The lipidomic analysis detected 949 lipids using exosomes from SEC, followed by 246 from lectin binding and 226 from TIM4 binding. The detectable metabolites showed SEC identifying 191 while lectin binding and TIM4 binding identified 100 and 107, respectively. When comparing uniquely detected molecules, different methods showed preferential enrichment of different sets of molecules with SEC enriching the greatest diversity. Compared to controls, SEC identified 28 lipids showing significant difference in NSCLC, while only 1 metabolite in NSCLC and 5 metabolites in CRPC were considered statistically significant (FDR < 0.1). Neither lectin-binding- nor TIM4-binding-derived exosome lipids or metabolites demonstrated significant differences between patient groups. We observed the highest EEI from SEC in lipids (NSCLC: 871.33) which was also noted in metabolites. These results support that the size exclusion method of exosome extraction implemented by SBI captures more heterogeneous exosome populations. In contrast, lectin-binding and TIM4-binding methods bind surface glycans or phosphatidylserine moieties of the exosomes. Overall, these findings suggest that specific isolation methods select subpopulations which may significantly impact cancer biomarker discovery.

Integrated proteomics identifies PARP inhibitor-induced prosurvival signaling changes as potential vulnerabilities in ovarian cancer.

BRCA1/2-deficient ovarian carcinoma (OC) has been shown to be particularly sensitive to poly (ADP-ribose) polymerase inhibitors (PARPis). Furthermore, BRCA1/2 mutation status is currently used as a predictive biomarker for PARPi therapy. Despite providing a major clinical benefit to the majority of patients, a significant proportion of BRCA1/2-deficient OC tumors do not respond to PARPis for reasons that are incompletely understood. Using an integrated chemical, phospho- and ADP-ribosylation proteomics approach, we sought here to develop additional mechanism-based biomarker candidates for PARPi therapy in OC and identify new targets for combination therapy to overcome primary resistance. Using chemical proteomics with PARPi baits in a BRCA1-isogenic OC cell line pair, as well as patient-derived BRCA1-proficient and BRCA1-deficient tumor samples, and subsequent validation by coimmunoprecipitation, we showed differential PARP1 and PARP2 protein complex composition in PARPi-sensitive, BRCA1-deficient UWB1.289 (UWB) cells compared to PARPi-insensitive, BRCA1-reconstituted UWB1.289+BRCA1 (UWB+B) cells. In addition, global phosphoproteomics and ADP-ribosylation proteomics furthermore revealed that the PARPi rucaparib induced the cell cycle pathway and nonhomologous end joining (NHEJ) pathway in UWB cells but downregulated ErbB signaling in UWB+B cells. In addition, we observed AKT PARylation and prosurvival AKT-mTOR signaling in UWB+B cells after PARPi treatment. Consistently, we found the synergy of PARPis with DNAPK or AKT inhibitors was more pronounced in UWB+B cells, highlighting these pathways as actionable vulnerabilities. In conclusion, we demonstrate the combination of chemical proteomics, phosphoproteomics, and ADP-ribosylation proteomics can identify differential PARP1/2 complexes and diverse, but actionable, drug compensatory signaling in OC.

Ovarian cancer immunogenicity is governed by a narrow subset of progenitor tissue-resident memory T cells.

Despite repeated associations between T cell infiltration and outcome, human ovarian cancer remains poorly responsive to immunotherapy. We report that the hallmarks of tumor recognition in ovarian cancer-infiltrating T cells are primarily restricted to tissue-resident memory (TRM) cells. Single-cell RNA/TCR/ATAC sequencing of 83,454 CD3+CD8+CD103+CD69+ TRM cells and immunohistochemistry of 122 high-grade serous ovarian cancers shows that only progenitor (TCF1low) tissue-resident T cells (TRMstem cells), but not recirculating TCF1+ T cells, predict ovarian cancer outcome. TRMstem cells arise from transitional recirculating T cells, which depends on antigen affinity/persistence, resulting in oligoclonal, trogocytic, effector lymphocytes that eventually become exhausted. Therefore, ovarian cancer is indeed an immunogenic disease, but that depends on ∼13% of CD8+ tumor-infiltrating T cells (∼3% of CD8+ clonotypes), which are primed against high-affinity antigens and maintain waves of effector TRM-like cells. Our results define the signature of relevant tumor-reactive T cells in human ovarian cancer, which could be applicable to other tumors with unideal mutational burden.

Utilizing digital pathology to quantify stromal caveolin-1 expression in malignant and benign ovarian tumors: Associations with clinicopathological parameters and clinical outcomes.

Loss of stromal caveolin-1 (Cav-1) is a biomarker of a cancer-associated fibroblast (CAF) phenotype and is related to progression, metastasis, and poor outcomes in several cancers. The objective of this study was to evaluate the clinical significance of Cav-1 expression in invasive epithelial ovarian cancer (OvCa). Epithelial and stromal Cav-1 expression were quantified in serous OvCa and benign ovarian tissue in two, independent cohorts-one quantified expression using immunohistochemistry (IHC) and the other using multiplex immunofluorescence (IF) with digital image analysis designed to target CAF-specific expression. Cav-1 expression was significantly downregulated in OvCa stroma compared to non-neoplastic stroma using both the IHC (p = 0.002) and IF (p = 1.8x10-13) assays. OvCa stroma showed Cav-1 downregulation compared to tumor epithelium with IHC (p = 1.2x10-24). Conversely, Cav-1 expression was higher in OvCa stroma compared to tumor epithelium with IF (p = 0.002). There was moderate correlation between IHC and IF methods for stromal Cav-1 expression (r2 = 0.69, p = 0.006) whereas there was no correlation for epithelial expression (r2 = 0.006, p = 0.98). Irrespective of the staining assay, neither response to therapy or overall survival correlated with the expression level of Cav-1 in the stroma or tumor epithelium. Our findings demonstrate a loss of stromal Cav-1 expression in ovarian serous carcinomas. Studies are needed to replicate these findings and explore therapeutic implications, particularly for immunotherapy response.

IgA transcytosis and antigen recognition govern ovarian cancer immunity.

Most ovarian cancers are infiltrated by prognostically relevant activated T cells1-3, yet exhibit low response rates to immune checkpoint inhibitors4. Memory B cell and plasma cell infiltrates have previously been associated with better outcomes in ovarian cancer5,6, but the nature and functional relevance of these responses are controversial. Here, using 3 independent cohorts that in total comprise 534 patients with high-grade serous ovarian cancer, we show that robust, protective humoral responses are dominated by the production of polyclonal IgA, which binds to polymeric IgA receptors that are universally expressed on ovarian cancer cells. Notably, tumour B-cell-derived IgA redirects myeloid cells against extracellular oncogenic drivers, which causes tumour cell death. In addition, IgA transcytosis through malignant epithelial cells elicits transcriptional changes that antagonize the RAS pathway and sensitize tumour cells to cytolytic killing by T cells, which also contributes to hindering malignant progression. Thus, tumour-antigen-specific and -antigen-independent IgA responses antagonize the growth of ovarian cancer by governing coordinated tumour cell, T cell and B cell responses. These findings provide a platform for identifying targets that are spontaneously recognized by intratumoural B-cell-derived antibodies, and suggest that immunotherapies that augment B cell responses may be more effective than approaches that focus on T cells, particularly for malignancies that are resistant to checkpoint inhibitors.

Pan-cancer analysis reveals TAp63-regulated oncogenic lncRNAs that promote cancer progression through AKT activation.

The most frequent genetic alterations across multiple human cancers are mutations in TP53 and the activation of the PI3K/AKT pathway, two events crucial for cancer progression. Mutations in TP53 lead to the inhibition of the tumour and metastasis suppressor TAp63, a p53 family member. By performing a mouse-human cross species analysis between the TAp63 metastatic mammary adenocarcinoma mouse model and models of human breast cancer progression, we identified two TAp63-regulated oncogenic lncRNAs, TROLL-2 and TROLL-3. Further, using a pan-cancer analysis of human cancers and multiple mouse models of tumour progression, we revealed that these two lncRNAs induce the activation of AKT to promote cancer progression by regulating the nuclear to cytoplasmic translocation of their effector, WDR26, via the shuttling protein NOLC1. Our data provide preclinical rationale for the implementation of these lncRNAs and WDR26 as therapeutic targets for the treatment of human tumours dependent upon mutant TP53 and/or the PI3K/AKT pathway.

BTN3A1 governs antitumor responses by coordinating αß and γδ T cells.

Gamma delta (γδ) T cells infiltrate most human tumors, but current immunotherapies fail to exploit their in situ major histocompatibility complex-independent tumoricidal potential. Activation of γδ T cells can be elicited by butyrophilin and butyrophilin-like molecules that are structurally similar to the immunosuppressive B7 family members, yet how they regulate and coordinate αß and γδ T cell responses remains unknown. Here, we report that the butyrophilin BTN3A1 inhibits tumor-reactive αß T cell receptor activation by preventing segregation of N-glycosylated CD45 from the immune synapse. Notably, CD277-specific antibodies elicit coordinated restoration of αß T cell effector activity and BTN2A1-dependent γδ lymphocyte cytotoxicity against BTN3A1+ cancer cells, abrogating malignant progression. Targeting BTN3A1 therefore orchestrates cooperative killing of established tumors by αß and γδ T cells and may present a treatment strategy for tumors resistant to existing immunotherapies.

Expression of the BAD pathway is a marker of triple-negative status and poor outcome.

Triple-negative breast cancer (TNBC) has few therapeutic targets, making nonspecific chemotherapy the main treatment. Therapies enhancing cancer cell sensitivity to cytotoxic agents could significantly improve patient outcomes. A BCL2-associated agonist of cell death (BAD) pathway gene expression signature (BPGES) was derived using principal component analysis (PCA) and evaluated for associations with the TNBC phenotype and clinical outcomes. Immunohistochemistry was used to determine the relative expression levels of phospho-BAD isoforms in tumour samples. Cell survival assays evaluated the effects of BAD pathway inhibition on chemo-sensitivity. BPGES score was associated with TNBC status and overall survival (OS) in breast cancer samples of the Moffitt Total Cancer Care dataset and The Cancer Genome Atlas (TCGA). TNBC tumours were enriched for the expression of phospho-BAD isoforms. Further, the BPGES was associated with TNBC status in breast cancer cell lines of the Cancer Cell Line Encyclopedia (CCLE). Targeted inhibition of kinases known to phosphorylate BAD protein resulted in increased sensitivity to platinum agents in TNBC cell lines compared to non-TNBC cell lines. The BAD pathway is associated with triple-negative status and OS. TNBC tumours were enriched for the expression of phosphorylated BAD protein compared to non-TNBC tumours. These findings suggest that the BAD pathway it is an important determinant of TNBC clinical outcomes.

Publisher Correction: ER stress-induced mediator C/EBP homologous protein thwarts effector T cell activity in tumors through T-bet repression.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Biologic Mechanisms Linked to Prognosis in Ovarian Cancer that May Be Affected by Aging.

The increase of both life expectancy of the Western industrialized population and cancer incidence with aging is expected to result in a rapid expansion of the elderly cancer population, including patients with epithelial ovarian cancer (EOC). Although the survival of patients with EOC has generally improved over the past three decades, this progress has yet to provide benefits for elderly patients. Compared with young age, advanced age has been reported as an adverse prognostic factor influencing EOC. However, contradicting results have been obtained, and the mechanisms underlying this observation are poorly defined. Few papers have been published on the underlying biological mechanisms that might explain this prognosis trend. We provide an extensive review of mechanisms that have been linked to EOC prognosis and/or aging in the published literature and might underlie this relationship in humans.

ER stress-induced mediator C/EBP homologous protein thwarts effector T cell activity in tumors through T-bet repression.

Understanding the intrinsic mediators that render CD8+ T cells dysfunctional in the tumor microenvironment is a requirement to develop more effective cancer immunotherapies. Here, we report that C/EBP homologous protein (Chop), a downstream sensor of severe endoplasmic reticulum (ER) stress, is a major negative regulator of the effector function of tumor-reactive CD8+ T cells. Chop expression is increased in tumor-infiltrating CD8+ T cells, which correlates with poor clinical outcome in ovarian cancer patients. Deletion of Chop in T cells improves spontaneous antitumor CD8+ T cell immunity and boosts the efficacy of T cell-based immunotherapy. Mechanistically, Chop in CD8+ T cells is elevated primarily through the ER stress-associated kinase Perk and a subsequent induction of Atf4; and directly represses the expression of T-bet, a master regulator of effector T cell function. These findings demonstrate the primary role of Chop in tumor-induced CD8+ T cell dysfunction and the therapeutic potential of blocking Chop or ER stress to unleash T cell-mediated antitumor immunity.

ERBB4 Expression in Ovarian Serous Carcinoma Resistant to Platinum-Based Therapy.

Few data exist on the prognostic and predictive impact of erb-b2 receptor tyrosine kinase 4 (ERBB4) in ovarian cancer. Thus, we evaluated ERBB4 expression by immunohistochemistry in a tumor microarray consisting of 100 ovarian serous carcinoma specimens (50 complete responses [CRs] and 50 incomplete responses [IRs] to platinum-based therapy), 51 normal tissue controls, and 16 ovarian cancer cell lines. H scores were used to evaluate expression and were semiquantitatively classified into low, intermediate, and high categories. Category frequencies were compared between tumor specimens vs controls using an unpaired t test. Among tumors, category frequencies were compared between CR and IR to chemotherapy. Overall survival (OS) was stratified by category. In total, 74 ovarian serous carcinoma samples (32 CRs and 42 IRs), 28 normal controls, and 16 ovarian cancer cell lines were evaluable. High-level ERBB4 expression was observed at a significantly higher frequency in ovarian serous carcinoma compared with normal control tissue. Among tumor specimens, ERBB4 expression was significantly higher for those with an IR to chemotherapy compared with CR (P = .033). OS was inversely correlated with ERBB4 expression levels. Median rates of OS were 18, 22, and 58 months among high-, intermediate-, and low-expression tumors, respectively. Our results indicate that ERBB4 expression by immunohistochemistry may correlate with chemotherapy-resistant ovarian serous carcinoma and shortened OS.

Sensitivity of ovarian cancer cells to acetaminophen reveals biological pathways that affect patient survival.

Experimental and epidemiological data support the potential activity of acetaminophen against ovarian cancer (OVCA). In this study, we sought to confirm the activity of acetaminophen in OVCA cell lines and to investigate the molecular basis of response. A total of 16 OVCA cell lines underwent pretreatment (baseline) genome-wide expression measurements and were then treated with and analyzed for acetaminophen sensitivity. Pearson's correlation analysis was performed to identify genes that were associated with OVCA acetaminophen response. The identified genes were subjected to pathway analysis, and the expression of each represented pathway was summarized using principal component analysis. OVCA acetaminophen response pathways were analyzed in 4 external clinico-genomic datasets from 820 women for associations with overall survival from OVCA. Acetaminophen exhibited antiproliferative activity against all tested OVCA cell lines, with half maximal inhibitory concentration values ranging from 63.2 to 403 µM. Pearson's correlation followed by biological pathway analysis identified 13 pathways to be associated with acetaminophen sensitivity (P<0.01). Associations were observed between patient survival from OVCA and expression of the following pathways: Development/angiotensin signaling via ß-arrestin (P=0.04), protein folding and maturation/angiotensin system maturation (P=0.02), signal transduction/c-Jun N-terminal kinase (JNK) pathway (P=0.03) and androstenedione and testosterone biosynthesis and metabolism (P=0.02). We confirmed that acetaminophen was active against OVCA cells in vitro. Furthermore, we identified 4 molecular signaling pathways associated with acetaminophen response that may also affect overall survival in women with OVCA, including the JNK pathway, which has been previously implicated in the mechanism of action of acetaminophen and is predictive of decreased survival in women with OVCA.

Molecular determinants for lymph node metastasis in clinically early-stage endometrial cancer.

Patients with occult lymph node metastasis in endometrioid-type endometrial cancer (EC) are prone to the development of recurrences and have worse outcomes compared with patients without lymph node metastasis. In the current study, the aim was to identify molecular parameters associated with lymph node metastasis in EC clinically early-stage disease. A univariate analysis of differentially expressed genes, proteins and clinicopathological parameters (including myometrial invasion and tumor grade) was performed, comparing EC patients with and without lymph node metastasis (n=262 patients from The Cancer Genome Atlas). Significant parameters were introduced in a multivariate model and a gene expression pathway analysis. Lymph node metastasis was associated with expression of 268 unique genes (P<0.001), 19 unique proteins (P<0.05), tumor grade and myometrial invasion in univariate analysis. Multivariate analysis demonstrated 10 genes independently associated with lymph node metastasis and 4 independently associated proteins. Myometrial invasion was the only independent clinicopathological parameter associated with lymph node status. The enrichment pathway analysis demonstrated that expression of epidermal growth factor receptor, Bcl2 antagonist of cell death and phosphatase and tensin homolog pathways were significantly involved in lymph node metastasis (P≤0.001). A gene expression signature to predict lymph node status in EC was created for future validation. Few studies have focused on the association between EC's molecular characteristics and nodal metastasis. Defining molecular risk factors for EC lymphatic nodal metastasis may help to individualize treatment and improve patient outcomes.

Micro-RNAs associated with the evolution of ovarian cancer cisplatin resistance.

OBJECTIVES: Ovarian cancer (OVCA) is the leading cause of mortality among women with gynecologic malignancy, in part due to the development of chemoresistance. We sought to identify micro-RNAs (miRNAs) associated with in vitro development of OVCA chemoresistance that may also represent potential targets for therapy. METHODS: In this study, four OVCA cell lines (A2780CP, A2780S, IGROV1, and OVCAR5) were serially treated with cisplatin in parallel with measurements of miRNA expression changes. RESULTS: Nine miRNAs were found to be associated with increasing cisplatin resistance (IC50) (p<0.01); however, only 5 of these miRNAs have publically available information. Pathway analysis identified 15 molecular signaling pathways that were represented by genes predicted to be targets of the 5 miRNAs (false discovery rate<0.05), 11 of which are associated with the epithelial-mesenchymal transition (EMT). Further analysis identified 2 of those pathways as being associated with overall survival in 218 patients with OVCA. CONCLUSIONS: Collectively, this panel of miRNAs associated with in vitro evolution of OVCA cisplatin resistance and the pathways identified to be associated with EMT and overall patient survival provide a framework for further investigations into EMT as a therapeutic target in patients with OVCA.

Prediction of Optimal Cytoreductive Surgery of Serous Ovarian Cancer With Gene Expression Data.

OBJECTIVES: Cytoreductive surgery is the cornerstone of ovarian cancer (OVCA) treatment. Detractors of initial maximal surgical effort argue that aggressive tumor biology will dictate survival, not the surgical effort. We investigated the role of biology in achieving optimal cytoreduction in serous OVCA using microarray gene expression analysis. METHODS: For the initial model, we used a gene expression signature from a microarray expression analysis of 124 women with serous OVCA, defining optimal cytoreduction as removal of all disease greater than 1 cm (with 64 women having optimal and 60 suboptimal cytoreduction). We then applied this model to 2 independent data sets: the Australian Ovarian Cancer Study (AOCS; 190 samples) and The Cancer Genome Atlas (TCGA; 468 samples). We performed a second analysis, defining optimal cytoreduction as removal of all disease to microscopic residual, using data from AOCS to create the gene signature and validating results in TCGA data set. RESULTS: Of the 12,718 genes included in the initial analysis, 58 predicted accuracy of cytoreductive surgery 69% of the time (P = 0.005). The performance of this classifier, measured by the area under the receiver operating characteristic curve, was 73%. When applied to TCGA and AOCS, accuracy was 56% (P = 0.16) and 62% (P = 0.01), respectively, with performance at 57% and 65%, respectively. In the second analysis, 220 genes predicted accuracy of cytoreductive surgery in the AOCS set 74% of the time, with performance of 73%. When these results were validated in TCGA set, accuracy was 57% (P = 0.31) and performance was at 62%. CONCLUSION: Gene expression data, used as a proxy of tumor biology, do not predict accurately nor consistently the ability to perform optimal cytoreductive surgery. Other factors, including surgical effort, may also explain part of the model. Additional studies integrating more biological and clinical data may improve the prediction model.

BAD-mediated apoptotic pathway is associated with human cancer development.

The malignant transformation of normal cells is caused in part by aberrant gene expression disrupting the regulation of cell proliferation, apoptosis, senescence and DNA repair. Evidence suggests that the Bcl-2 antagonist of cell death (BAD)-mediated apoptotic pathway influences cancer chemoresistance. In the present study, we explored the role of the BAD-mediated apoptotic pathway in the development and progression of cancer. Using principal component analysis to derive a numeric score representing pathway expression, we evaluated clinico-genomic datasets (n=427) from corresponding normal, pre-invasive and invasive cancers of different types, such as ovarian, endometrial, breast and colon cancers in order to determine the associations between the BAD-mediated apoptotic pathway and cancer development. Immunofluorescence was used to compare the expression levels of phosphorylated BAD [pBAD (serine-112, -136 and -155)] in immortalized normal and invasive ovarian, colon and breast cancer cells. The expression of the BAD-mediated apoptotic pathway phosphatase, PP2C, was evaluated by RT-qPCR in the normal and ovarian cancer tissue samples. The growth-promoting effects of pBAD protein levels in the immortalized normal and cancer cells were assessed using siRNA depletion experiments with MTS assays. The expression of the BAD-mediated apoptotic pathway was associated with the development and/or progression of ovarian (n=106, p<0.001), breast (n=185, p<0.0008; n=61, p=0.04), colon (n=22, p<0.001) and endometrial (n=33, p<0.001) cancers, as well as with ovarian endometriosis (n=20, p<0.001). Higher pBAD protein levels were observed in the cancer cells compared to the immortalized normal cells, whereas PP2C gene expression was lower in the cancer compared to the ovarian tumor tissue samples (n=76, p<0.001). The increased pBAD protein levels after the depletion of PP2C conferred a growth advantage to the immortalized normal and cancer cells. The BAD-mediated apoptotic pathway is thus associated with the development of human cancers likely influenced by the protein levels of pBAD.

The Chinese herb polyphyllin D sensitizes ovarian cancer cells to cisplatin-induced growth arrest.

PURPOSE: We evaluated the effects of polyphyllin D (PD), a natural compound with anti-neoplastic activity and a major component of the Chinese herb Paris polyphylla, on ovarian cancer (OVCA) cell line proliferation and platinum sensitivity. METHODS: A panel of 20 OVCA cell lines was subjected to PD treatment, MTS proliferation assays, and determination of IC50. Pre-treatment, baseline genome-wide Affymetrix expression analysis was performed on each cell line, and Pearson's correlation was performed to identify genes associated with OVCA PD sensitivity. Twelve cell lines were treated with PD with and without cisplatin, and the effects of PD on cisplatin IC50 were quantified. Genes associated with OVCA PD sensitivity were evaluated for associations with survival in a publically available clinico-genomic dataset of 218 patients with OVCA. RESULTS: Our results showed that PD exhibited anti-proliferative effects against all OVCA cell lines tested, with IC50 values ranging from 0.2 to 1.4 µm. Furthermore, in all cell lines, PD treatment significantly decreased cisplatin IC50 (mean IC50 reduction of 2.1 µm; P < 0.02). Pearson's correlation test identified 25 probe sets, representing 18 unique genes to be associated with PD sensitivity (FDR = 0). We found that one of these genes was associated with overall survival in women with OVCA: CLDN4 (P = 0.014). CONCLUSION: Our findings highlight the value of PD as a natural product with anti-cancer properties, which may also enhance the activity of existing therapeutic agents.

Metabolic vulnerabilities in endometrial cancer.

Women with metabolic disorders, including obesity and diabetes, have an increased risk of developing endometrial cancer. However, the metabolism of endometrial tumors themselves has been largely understudied. Comparing human endometrial tumors and cells with their nonmalignant counterparts, we found that upregulation of the glucose transporter GLUT6 was more closely associated with the cancer phenotype than other hallmark cancer genes, including hexokinase 2 and pyruvate kinase M2. Importantly, suppression of GLUT6 expression inhibited glycolysis and survival of endometrial cancer cells. Glycolysis and lipogenesis were also highly coupled with the cancer phenotype in patient samples and cells. To test whether targeting endometrial cancer metabolism could be exploited as a therapeutic strategy, we screened a panel of compounds known to target diverse metabolic pathways in endometrial cells. We identified that the glycolytic inhibitor, 3-bromopyruvate, is a powerful antagonist of lipogenesis through pyruvylation of CoA. We also provide evidence that 3-bromopyruvate promotes cell death via a necrotic mechanism that does not involve reactive oxygen species and that 3-bromopyruvate impaired the growth of endometrial cancer xenografts.