Activin levels correlate with lymphocytic infiltration in epithelial ovarian cancer.

OBJECTIVE: The TGF-ß superfamily member activin, a dimer of the gene products of INHBA and/or INHBB, has been implicated in immune cell maturation and recruitment, but its immune impact within epithelial ovarian cancer (EOC) is not well characterized. We sought to explore differences in activin (INHBA/ Inhibin-ßA and INHBB/ Inhibin-ßB) between malignant and ovarian tissues at the RNA and protein level and assess the relationship between activin and immune cells in EOC. METHODS: Publicly available RNA sequencing data were accessed from GEO (#GSE143897) with normalization and quantification performed via DESeq2. Immune gene expression profile was further explored within the TCGA-OV cohort derived from The Cancer Genome Atlas (TCGA). Immunohistochemical analysis was performed to evaluate activin A and T-cell markers CD8 and FoxP3 at the protein level. ELISA to activin-A was used to assess levels in the ascites of advanced EOC patients. Kaplan-Meier curves were generated to visualize survival outcomes. RESULTS: Gene expression levels of components of the activin signaling pathway were elevated within EOC when compared to a benign cohort, with differences in activin type I/II receptor gene profiles identified. Additionally, INHBA gene expression was linked to lymphocytic immune markers in EOC samples. Immunohistochemistry analysis revealed a positive correlation of CD8 and FOXP3 staining with activin A at the protein level in both primary and metastatic epithelial ovarian cancer samples. Furthermore, Activin-A (inhibin-ßA) is significantly elevated in EOC patient ascites. CONCLUSION: INHBA expression is elevated within EOC, correlating with worse survival, with activin protein levels correlating with specific immune infiltration. Our findings suggest that activin-A may play a role in suppressing anti-tumor immunity in EOC, highlighting its potential as a therapeutic target.

Targeted therapy in high grade serous ovarian Cancer: A literature review.

Ovarian cancer continues to have a high mortality rate despite therapeutic advances. Traditionally, treatment has focused on surgery followed by systemic platinum- based chemotherapy. Unfortunately, most patients develop resistance to platinum agents, highlighting the need for targeted therapies. PARP inhibitors and anti-angiogenic agents, such as bevacizumab, have more recently changed upfront therapy. Unfortunately, other targeted therapies including immunotherapy have not seen the same success. Emerging therapeutic targets and modalities such as small molecule tyrosine kinase inhibitors, lipid metabolism targeting agents, gene therapy, ribosome targeted drugs as well as several other therapeutic classes have been and are currently under investigation. In this review, we discuss targeted therapies in high grade serous ovarian cancer from preclinical studies to phase III clinical trials.

Five-Year Relative Survival Rates of Women Diagnosed with Uterine Cancer by County-Level Socioeconomic Status Overall and across Histology and Race/Ethnicity.

Understanding socioeconomic factors contributing to uterine cancer survival disparities is crucial, especially given the increasing incidence of uterine cancer, which disproportionately impacts racial/ethnic groups. We investigated the impact of county-level socioeconomic factors on five-year survival rates of uterine cancer overall and by histology across race/ethnicity. We included 333,013 women aged ≥ 30 years with microscopically confirmed uterine cancers (2000-2018) from the Surveillance, Epidemiology, and End Results 22 database followed through 2019. Age-standardized five-year relative survival rates were compared within race/ethnicity and histology, examining the differences across tertiles of county-level percent (%)

Proteobacteria impair anti-tumor immunity in the omentum by consuming arginine.

Gut microbiota influence anti-tumor immunity, often by producing immune-modulating metabolites. However, microbes consume a variety of metabolites that may also impact host immune responses. We show that tumors grow unchecked in the omenta of microbe-replete mice due to immunosuppressive Tregs. By contrast, omental tumors in germ-free, neomycin-treated mice or mice colonized with altered Schaedler's flora (ASF) are spontaneously eliminated by CD8+ T cells. These mice lack Proteobacteria capable of arginine catabolism, causing increases in serum arginine that activate the mammalian target of the rapamycin (mTOR) pathway in Tregs to reduce their suppressive capacity. Transfer of the Proteobacteria, Escherichia coli (E. coli), but not a mutant unable to catabolize arginine, to ASF mice reduces arginine levels, restores Treg suppression, and prevents tumor clearance. Supplementary arginine similarly decreases Treg suppressive capacity, increases CD8+ T cell effectiveness, and reduces tumor burden. Thus, microbial consumption of arginine alters anti-tumor immunity, offering potential therapeutic strategies for tumors in visceral adipose tissue.

Uterine cancer incidence trends and 5-year relative survival by race/ethnicity and histology among women under 50 years.

BACKGROUND: Uterine cancers diagnosed before age 50 years are increasing in the U.S., but changes in clinical characteristics and survival over time across racial/ethnic groups have not been previously described. OBJECTIVE: To investigate age-adjusted, hysterectomy corrected incidence rates and trends, and 5-year relative survival rates of uterine cancer in women aged <50 years, overall and stratified by race/ethnicity and histology. STUDY DESIGN: We included microscopically confirmed uterine cancer cases (diagnosed 2000-2019) in women aged 20 to 49 years from the Surveillance, Epidemiology, and End Results Program. Age-adjusted incidence and 5-year relative survival rates, and 95% confidence intervals were computed using Surveillance, Epidemiology, and End Results (SEER) ∗Stat and compared across time periods (2000-2009 and 2010-2019). Incidence rates were adjusted for hysterectomy prevalence using Behavioral Risk Factor Surveillance System data, and trends were computed using the Joinpoint regression program. RESULTS: We included 57,128 uterine cancer cases. The incidence of uterine cancer increased from 10.1 per 100,000 in 2000-2009 to 12.0 per 100,000 in 2010-2019, increasing at an annual rate of 1.7%/y for the entire period. Rising trends were more pronounced among women <40 years (3.0%/y and 3.3%/y in 20-29 and 30-39 years, respectively) than in those 40 to 49 years (1.3%/y), and among underrepresented racial/ethnic groups (Hispanic 2.8%/y, non-Hispanic-Black 2.7%, non-Hispanic-Asian/Pacific Islander 2.1%) than in non-Hispanic-White (0.9%/y). Recent (2010-2019) incidence rates were highest for endometrioid (9.6 per 100,000), followed by sarcomas (1.2), and nonendometrioid subtypes (0.9). Rates increased significantly for endometrioid subtypes at 1.9%/y from 2000 to 2019. Recent endometrioid and nonendometrioid rates were highest in non-Hispanic-Native American/Alaska Native (15.2 and 1.4 per 100,000), followed by Hispanic (10.9 and 1.0), non-Hispanic-Asian/Pacific Islander (10.2 and 0.9), non-Hispanic-White (9.4 and 0.8), and lowest in non-Hispanic-Black women (6.4 and 0.8). Sarcoma rates were highest in non-Hispanic-Black women (1.8 per 100,000). The 5-year relative survival remained unchanged over time for women with endometrioid (from 93.4% in 2000-2009 to 93.9% in 2010-2019, P≥.05) and nonendometrioid subtypes (from 73.2% to 73.2%, P≥.05) but decreased for women with sarcoma from 69.8% (2000-2009) to 66.4% (2010-2019, P<.05). CONCLUSION: Uterine cancer incidence rates in women <50 years have increased from 2000 to 2019 while survival has remained relatively unchanged. Incidence trends can be primarily attributed to increasing rates of cancers with endometrioid histology, with the greatest increases observed among non-Hispanic-Black, Hispanic, and non-Hispanic-Asian/Pacific Islander. Sarcomas, while much rarer, were the second most common type of uterine cancer among women <50 years and have poor prognosis and apparent decreasing survival over time. Rising rates of uterine cancer and the distinct epidemiologic patterns among women <50 years highlight the need for effective prevention and early detection strategies for uterine cancer in this age group.

Association of allostatic load with overall survival in epithelial ovarian cancer.

OBJECTIVE: Elevated allostatic load (AL), an integrated, cumulative marker of physiologic damage due to socioenvironmental stress, is associated with increased mortality in patients with breast, lung, and other cancers. The relationship between allostatic load and mortality in ovarian cancer patients remains unknown. We examined the relationship between allostatic load and overall survival in ovarian cancer patients. METHODS: This cross-sectional study used data from 201 patients enrolled in a prospective observational ovarian cancer cohort study at a National Cancer Institute-designated Comprehensive Cancer Center from October 2012 through June 2022. All patients underwent debulking surgery and completed a full course of standard-of-care platinum-based chemotherapy. Follow-up was completed through January 2024. Allostatic load was calculated as a summary score by assigning one point to the worst sample quartile for each of ten biomarkers measured within 45 days before the ovarian cancer diagnosis. High allostatic load was defined as having an allostatic load in the top quartile of the summary score. A Cox proportional hazard model with robust variance tested the association between allostatic load and overall survival. RESULTS: There were no associations between allostatic load and ovarian cancer clinical characteristics. After accounting for demographic, clinical, and treatment factors, high allostatic load was associated with a significant increase in mortality (hazard ratio 2.17 [95%CI, 1.13-4.15]; P = 0.02). CONCLUSION: Higher allostatic load is associated with worse survival among ovarian cancer patients. Allostatic load could help identify patients at risk for poorer outcomes who may benefit from greater socioenvironmental support during treatment.

Bridging the Gap from Bench to Bedside: A Call for In Vivo Preclinical Models to Advance Endometrial Cancer and Cervical Cancer Immuno-oncology Research.

Advanced-stage endometrial and cervical cancers are associated with poor outcomes despite contemporary advances in surgical techniques and therapeutics. Recent clinical trial results have led to a shift in the treatment paradigm for both malignancies, in which immunotherapy is now incorporated as the standard of care up front for most patients with advanced endometrial and cervical cancers as the standard of care. Impressive response rates have been observed, but unfortunately, a subset of patients do not benefit from immunotherapy, and survival remains poor. Continued preclinical research and clinical trial development are crucial for our understanding of resistance mechanisms to immunotherapy and maximization of therapeutic efficacy. In this setting, syngeneic models are preferred over xenograft models as they allow for the evaluation of the tumor-immune interaction in an immunocompetent host, most closely mimicking the tumor-immune interaction in patients with cancer. Unfortunately, significant disparities exist about syngeneic models in gynecologic malignancy, in which queries from multiple large bioscience companies confirm no commercial availability of endometrial or cervical cancer syngeneic cell lines. Published data exist about the recent development of several endometrial and cervical cancer syngeneic cell lines, warranting further investigation. Closing the disparity gap for preclinical models in endometrial and cervical cancers will support physician scientists, basic and translational researchers, and clinical trialists who are dedicated to improving outcomes for our patients with advanced disease and poor prognosis.

Dedicated financial hardship screening adds value to routine distress screening among gynecologic cancer patients.

OBJECTIVES: To evaluate existing distress screening to identify patients with financial hardship (FH) compared to dedicated FH screening and assess patient attitudes toward FH screening. METHODS: We screened gynecologic cancer patients starting a new line of therapy. Existing screening included: (1) Moderate/severe distress defined as Distress Thermometer score ≥ 4, (2) practical concerns identified from Problem Checklist, and (3) a single question assessing trouble paying for medications. FH screening included: (1) Comprehensive Score for Financial Toxicity (COST) tool and (2) 10-item Financial Needs Checklist to guide referrals. FH was defined as COST score < 26. We calculated sensitivity (patients with moderate/severe distress + FH over total patients with FH) and specificity (patients with no/mild distress + no FH over total patients with no FH) to assess the extent distress screening could capture FH. Surveys and exit interviews assessed patient perspectives toward screening. RESULTS: Of 364 patients screened for distress, average age was 62 years, 25% were Black, 45% were Medicare beneficiaries, 32% had moderate/severe distress, 15% reported ≥1 practical concern, and 0 reported trouble paying for medications. Most (n = 357, 98%) patients also completed FH screening: of them, 24% screened positive for FH, 32% reported ≥1 financial need. Distress screening had 57% sensitivity and 77% specificity for FH. Based on 79 surveys and 43 exit interviews, FH screening was acceptable with feedback to improve the timing and setting of screening. CONCLUSIONS: Dedicated FH screening was feasible and acceptable, but sensitivity was low. Importantly, 40% of women with FH would not have been identified with distress screening alone.

A spatial proteomic study of platinum refractory HGSOC implicates dual AKT and WNT activity linked to an immunosuppressive tumor microenvironment.

OBJECTIVE: Advanced-stage high-grade serous ovarian cancer (HGSOC) remains a deadly gynecologic malignancy with high rates of disease recurrence and limited, effective therapeutic options for patients. There is a significant need to better stratify HGSOC patients into platinum refractory (PRF) vs. sensitive (PS) cohorts at baseline to improve therapeutic responses and survival outcomes for PRF HGSOC. METHODS: We performed NanoString for GeoMx Digital Spatial Profile (G-DSP) multiplex protein analysis on PRF and PS tissue microarrays (TMAs) to study the bidirectional communication of cancer cells with immune cells in the tumor microenvironment (TME) of HGSOC. We demonstrate robust stratification of PRF and PS tumors at baseline using multiplex spatial proteomic biomarkers with implications for tailoring subsequent therapy. RESULTS: PS patients had elevated apoptotic and anti-tumor immune profiles, while PRF patients had dual AKT1 and WNT signaling with immunosuppressive profiles. We found that dual activity of AKT1 and WNT signaling supported the exclusion of immune cells, specifically tumor infiltrating lymphocytes (TILs), from the TME in PRF tumors, and this was not observed in PS tumors. The exclusion of immune cells from the TME of PRF tumors corresponded to abnormal endothelial cell structure in tumors with dual AKT1 and WNT signaling activity. CONCLUSIONS: We believe our findings provide improved understanding of tumor-immune crosstalk in HGSOC TME highlighting the importance of the relationship between AKT and WNT pathways, immune cell function, and platinum response in HGSOC.

Ofranergene Obadenovec (Ofra-Vec, VB-111) With Weekly Paclitaxel for Platinum-Resistant Ovarian Cancer: Randomized Controlled Phase III Trial (OVAL Study/GOG 3018).

PURPOSE: To evaluate the addition of ofranergene obadenovec (ofra-vec, VB-111), a novel gene-based anticancer targeted therapy, to once a week paclitaxel in patients with recurrent platinum-resistant ovarian cancer (PROC). METHODS: This placebo-controlled, double-blind, phase III trial (ClinicalTrials.gov identifier: NCT03398655) randomly assigned patients with PROC 1:1 to receive intravenous ofra-vec every 8 weeks with once a week IV paclitaxel or placebo with paclitaxel until disease progression. The dual primary end points were overall survival (OS) and progression-free survival (PFS) as assessed by Blinded Independent Central Review. RESULTS: Between December 2017 and March 2022, 409 patients were randomly assigned. The median PFS was 5.29 months in the ofra-vec arm and 5.36 months in the control arm, hazard ratio (HR) 1.03 (CI, 0.83 to 1.29; P = .7823). The median OS with ofra-vec was 13.37 months versus 13.14 months, HR 0.97 (CI, 0.75 to 1.27; P = .8440). Objective response rates (ORRs) per RECIST 1.1 were similar in both arms: 28.9% with ofra-vec versus 29.6% with control. In both treatment arms, response to CA-125 was a substantial prognostic factor for both PFS and OS. In the ofra-vec arm, the HR in CA-125 responders compared with that in nonresponders for PFS was 0.2428 (CI, 0.1642 to 0.3588), and for OS, the HR was 0.3343 (CI, 0.2134 to 0.5238). Safety profile was characterized by common transient flu-like symptoms such as fever and chills. CONCLUSION: The addition of ofra-vec to paclitaxel did not improve PFS or OS. The PFS and ORR in the control arm exceeded the results that were anticipated on the basis of the AURELIA chemotherapy control arm. CA-125 response was a substantial prognostic biomarker for PFS and OS in patients with PROC treated with paclitaxel.

Nivolumab Plus Ipilimumab in Patients With Solid Tumors With ATM Mutations: Results From the Targeted Agent and Profiling Utilization Registry (TAPUR) Study.

PURPOSE: The Targeted Agent and Profiling Utilization Registry Study is a phase II basket study evaluating the antitumor activity of commercially available targeted agents in patients with advanced cancers with genomic alterations known to be drug targets. Results of a cohort of patients with solid tumors with ATM mutations treated with nivolumab plus ipilimumab are reported. METHODS: Eligible patients had measurable disease (RECIST v.1.1), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and no standard treatment options. Primary end point was disease control (DC), defined as complete (CR) or partial (PR) response or stable disease (SD) of at least 16 weeks duration (SD16+). Low-accruing histology-specific cohorts with ATM mutations treated with nivolumab plus ipilimumab were collapsed into a single histology-pooled cohort for this analysis. The results were evaluated based on a one-sided exact binomial test with a null DC rate of 15% versus 35% (power = .84; α = .10). Secondary end points were objective response (OR), progression-free survival, overall survival, duration of response, duration of SD, and safety. RESULTS: Twenty-nine patients with 10 tumor types with ATM mutations were enrolled from January 2018 to May 2020. One patient was not evaluable for efficacy. One CR, three PR, and three SD16+ were observed for DC and OR rates of 24% (P = .13; one-sided 90% CI: 14 to 100) and 14% (95% CI: 4 to 32), respectively. The null hypothesis of 15% DC rate was not rejected. Eleven patients had one treatment-related grade 3 adverse event (AE) or serious AE. There were two treatment-related patient deaths including immune-related encephalitis and respiratory failure. CONCLUSION: Nivolumab plus ipilimumab did not meet prespecified criteria to declare a signal of activity in patients with solid tumors with ATM mutations.

Immune responses, therapeutic anti-tumor effects, and tolerability upon therapeutic HPV16/18 E6/E7 DNA vaccination via needle-free biojector.

IMPORTANCE: Respectively, HPV16 and HPV18 cause 50% and 20% of cervical cancer cases globally. Viral proteins E6 and E7 are obligate drivers of oncogenic transformation. We recently developed a candidate therapeutic DNA vaccine, pBI-11, that targets HPV16 and HPV18 E6 and E7. Single-site intramuscular delivery of pBI-11 via a needle elicited therapeutic anti-tumor effects in mice and is now being tested in high-risk human papillomavirus+ head and neck cancer patients (NCT05799144). Needle-free biojectors such as the Tropis device show promise due to ease of administration, high patient acceptability, and the possibility of improved delivery. For example, vaccination of patients with the ZyCoV-D DNA vaccine using the Tropis device is effective against COVID19, well tolerated, and licensed. Here we show that split-dose, multi-site administration and intradermal delivery via the Tropis biojector increase the delivery of pBI-11 DNA vaccine, enhance HPV antigen-specific CD8+ T-cell responses, and improve anti-tumor therapeutic effects, suggesting its translational potential to treat HPV16/18 infection and disease.

TP53 mutation and abnormal p53 expression in endometrial cancer: Associations with race and outcomes.

OBJECTIVE: This multi-center cohort study assessed associations between race, TP53 mutations, p53 expression, and histology to investigate racial survival disparities in endometrial cancer (EC). METHODS: Black and White patients with advanced or recurrent EC with Next Generation Sequencing data in the Endometrial Cancer Molecularly Targeted Therapy Consortium database were identified. Clinicopathologic and treatment variables were summarized by race and compared. Overall survival (OS) and progression-free survival (PFS) among all patients were estimated by the Kaplan-Meier method. Cox proportional hazards models estimated the association between race, TP53 status, p53 expression, histology, and survival outcomes. RESULTS: Black patients were more likely than White patients to have TP53-mutated (N = 727, 71.7% vs 49.7%, p < 0.001) and p53-abnormal (N = 362, 71.1% vs 53.2%, p = 0.003) EC. Patients with TP53-mutated EC had worse PFS (HR 2.73 (95% CI 1.88-3.97)) and OS (HR 2.20 (95% CI 1.77-2.74)) compared to those with TP53-wildtype EC. Patients with p53-abnormal EC had worse PFS (HR 2.01 (95% CI 1.22-3.32)) and OS (HR 1.61 (95% CI 1.18-2.19)) compared to those with p53-wildtype EC. After adjusting for TP53 mutation and p53 expression, race was not associated with survival outcomes. The most frequent TP53 variants were at nucleotide positions R273 (n = 54), R248 (n = 38), and R175 (n = 23), rates of which did not differ by race. CONCLUSIONS: Black patients are more likely to have TP53-mutated and p53-abnormal EC, which are associated with worse survival outcomes than TP53- and p53-wildtype EC. The higher frequency of these subtypes among Black patients may contribute to survival disparities.

Proteogenomic insights suggest druggable pathways in endometrial carcinoma.

We characterized a prospective endometrial carcinoma (EC) cohort containing 138 tumors and 20 enriched normal tissues using 10 different omics platforms. Targeted quantitation of two peptides can predict antigen processing and presentation machinery activity, and may inform patient selection for immunotherapy. Association analysis between MYC activity and metformin treatment in both patients and cell lines suggests a potential role for metformin treatment in non-diabetic patients with elevated MYC activity. PIK3R1 in-frame indels are associated with elevated AKT phosphorylation and increased sensitivity to AKT inhibitors. CTNNB1 hotspot mutations are concentrated near phosphorylation sites mediating pS45-induced degradation of ß-catenin, which may render Wnt-FZD antagonists ineffective. Deep learning accurately predicts EC subtypes and mutations from histopathology images, which may be useful for rapid diagnosis. Overall, this study identified molecular and imaging markers that can be further investigated to guide patient stratification for more precise treatment of EC.

Evolving roles of activins and inhibins in ovarian cancer pathophysiology.

Activins and inhibins are unique members of the transforming growth factor-ß (TGFß) family of growth factors, with the ability to exert autocrine, endocrine, and paracrine effects in a wide range of complex physiologic and pathologic processes. Although first isolated within the pituitary, emerging evidence suggests broader influence beyond reproductive development and function. Known roles of activin and inhibin in angiogenesis and immunity along with correlations between gene expression and cancer prognosis suggest potential roles in tumorigenesis. Here, we present a review of the current understanding of the biological role of activins and inhibins as it relates to ovarian cancers, summarizing the underlying signaling mechanisms and physiologic influence, followed by detailing their roles in cancer progression, diagnosis, and treatment.

Racial and Ethnic Disparities in Cervical Cancer Incidence, Survival, and Mortality by Histologic Subtype.

PURPOSE: We conducted an integrated population-based analysis of histologic subtype-specific cervical cancer incidence, survival, and incidence-based mortality by race and ethnicity, with correction for hysterectomy prevalence. METHODS: Using the SEER 21 and 18 registries, we selected primary cases of malignant cervical cancer diagnosed among women ≥ 15 years. We evaluated age-adjusted incidence rates among cases diagnosed between 2000 and 2018 (SEER21) and incidence-based mortality rates among deaths from 2005 to 2018 (SEER18), per 100,000 person-years. Rates were stratified by histologic subtype and race/ethnicity (incidence and mortality), and stage, age at diagnosis, and county-level measures of social determinants of health (incidence only). Incidence and mortality rates were corrected for hysterectomy using data from the Behavioral Risk Factor Surveillance System. We estimated 5-year relative survival by histologic subtype and stratified by stage at diagnosis. RESULTS: Incidence rates of cervical squamous cell carcinoma were highest in Black and Hispanic women, while incidence rates of cervical adenocarcinoma (ADC) were highest among Hispanic and White women, particularly for localized ADC. County-level income and education variables were inversely associated with squamous cell carcinoma incidence rates in all racial and ethnic groups but had less influence on ADC incidence rates. Black women had the highest overall mortality rates and lowest 5-year relative survival, irrespective of subtype and stage. Disparities in survival were particularly pronounced for Black women with regional and distant ADC, compared with other racial/ethnic groups. CONCLUSION: Although Black women are less likely to be diagnosed with ADC compared with all other racial/ethnic groups, they experience the highest mortality rates for this subtype, likely attributed to the poor survival observed for Black women with regional and distant ADC.

Reciprocal SOX2 regulation by SMAD1-SMAD3 is critical for anoikis resistance and metastasis in cancer.

Growth factors in tumor environments are regulators of cell survival and metastasis. Here, we reveal the dichotomy between TGF-ß superfamily growth factors BMP and TGF-ß/activin and their downstream SMAD effectors. Gene expression profiling uncovers SOX2 as a key contextual signaling node regulated in an opposing manner by BMP2, -4, and -9 and TGF-ß and activin A to impact anchorage-independent cell survival. We find that SOX2 is repressed by BMPs, leading to a reduction in intraperitoneal tumor burden and improved survival of tumor-bearing mice. Repression of SOX2 is driven by SMAD1-dependent histone H3K27me3 recruitment and DNA methylation at SOX2's promoter. Conversely, TGF-ß, which is elevated in patient ascites, and activin A can promote SOX2 expression and anchorage-independent survival by SMAD3-dependent histone H3K4me3 recruitment. Our findings identify SOX2 as a contextual and contrastingly regulated node downstream of TGF-ß members controlling anchorage-independent survival and metastasis in ovarian cancers.

PVT1 is a stress-responsive lncRNA that drives ovarian cancer metastasis and chemoresistance.

Metastatic growth of ovarian cancer cells into the peritoneal cavity requires adaptation to various cellular stress factors to facilitate cell survival and growth. Here, we demonstrate the role of PVT1, one such stress induced long non-coding RNA, in ovarian cancer growth and metastasis. PVT1 is an amplified and overexpressed lncRNA in ovarian cancer with strong predictive value for survival and response to targeted therapeutics. We find that expression of PVT1 is regulated by tumor cells in response to cellular stress, particularly loss of cell-cell contacts and changes in matrix rigidity occurring in a YAP1-dependent manner. Induction of PVT1 promotes tumor cell survival, growth, and migration. Conversely, reducing PVT1 levels robustly abrogates metastatic behavior and tumor cell dissemination in cell lines and syngeneic transplantation models in vivo. We find that reducing PVT1 causes widespread changes in the transcriptome leading to alterations in cellular stress response and metabolic pathways including doxorubicin metabolism, which impacts chemosensitivity. Together, these findings implicate PVT1 as a promising therapeutic target to suppress metastasis and chemoresistance in ovarian cancer.

Homologous Recombination Deficiency: Concepts, Definitions, and Assays.

BACKGROUND: Homologous recombination deficiency (HRD) is a phenotype that is characterized by the inability of a cell to effectively repair DNA double-strand breaks using the homologous recombination repair (HRR) pathway. Loss-of-function genes involved in this pathway can sensitize tumors to poly(adenosine diphosphate [ADP]-ribose) polymerase (PARP) inhibitors and platinum-based chemotherapy, which target the destruction of cancer cells by working in concert with HRD through synthetic lethality. However, to identify patients with these tumors, it is vital to understand how to best measure homologous repair (HR) status and to characterize the level of alignment in these measurements across different diagnostic platforms. A key current challenge is that there is no standardized method to define, measure, and report HR status using diagnostics in the clinical setting. METHODS: Friends of Cancer Research convened a consortium of project partners from key healthcare sectors to address concerns about the lack of consistency in the way HRD is defined and methods for measuring HR status. RESULTS: This publication provides findings from the group's discussions that identified opportunities to align the definition of HRD and the parameters that contribute to the determination of HR status. The consortium proposed recommendations and best practices to benefit the broader cancer community. CONCLUSION: Overall, this publication provides additional perspectives for scientist, physician, laboratory, and patient communities to contextualize the definition of HRD and various platforms that are used to measure HRD in tumors.

Circulating Tregs Accumulate in Omental Tumors and Acquire Adipose-Resident Features.

Tumors that metastasize in the peritoneal cavity typically end up in the omental adipose tissue, a particularly immune-suppressive environment that includes specialized adipose-resident regulatory T cells (Treg). Tregs rapidly accumulate in the omentum after tumor implantation and potently suppress antitumor immunity. However, it is unclear whether these Tregs are recruited from the circulation or derived from preexisting adipose-resident Tregs by clonal expansion. Here we show that Tregs in tumor-bearing omenta predominantly have thymus-derived characteristics. Moreover, naïve tumor antigen-specific CD4+ T cells fail to differentiate into Tregs in tumor-bearing omenta. In fact, Tregs derived from the pretumor repertoire are sufficient to suppress antitumor immunity and promote tumor growth. However, tumor implantation in the omentum does not promote Treg clonal expansion, but instead leads to increased clonal diversity. Parabiosis experiments show that despite tissue-resident (noncirculating) characteristics of omental Tregs in naïve mice, tumor implantation promotes a rapid influx of circulating Tregs, many of which come from the spleen. Finally, we show that newly recruited Tregs rapidly acquire characteristics of adipose-resident Tregs in tumor-bearing omenta. These data demonstrate that most Tregs in omental tumors are recruited from the circulation and adapt to their environment by altering their homing, transcriptional, and metabolic properties.