Outcome In Ovarian Cancer Patients Research Articles

Abstract 5906: NUAK2 is highly overexpressed in ovarian cancer and the overexpression of its nuclear form correlates with tumor aggressiveness

Abstract NUAK2, also known as sucrose non-fermenting (SNF1)-like AMPK-related kinase (SNARK), belongs to the AMPK serine/threonine kinase family. While little is known about the exact biological functions of NUAK2, this kinase has been reported to be overexpressed in multiple cancer types, forming a part of the 1q32 amplicon common in human cancer. When we analysed its expression in the ovarian datasets of The Cancer Genome Atlas and Genotype-Tissue Expression involving 418 ovarian carcinomas and 88 normal ovarian tissues, the level of NUAK2 mRNA was approximately 64-fold elevated in ovarian cancer relative to normal ovaries (p<0.0001). Herein, we aim to gain insights into the potential relevance of NUAK2 overexpression in ovarian cancer and to characterize the functional roles of NUAK2 involved in ovarian carcinogenesis. We performed an immunohistochemical study of NUAK2 in a clinical archive of ovarian tumor tissues, a cohort consisting of 10 cases of benign ovarian tumors, 9 cases of borderline ovarian tumors, and 88 cases of ovarian carcinomas. Representative ovarian tumor regions of each individual case were analysed using ImageScope, and a histoscore was then generated as a product of staining percentage and intensity. Histoscores together with clinicopathological data of each patient were subjected to statistical analysis by SPSS and GraphPad. In concordance with the public database, the level of NUAK2 protein was significantly higher in ovarian cancer tissues compared to benign and borderline ovarian tissues (p<0.0001). Histoscores of nuclear NUAK2 in particular were positively correlated with high FIGO grade (p=0.0048); a trend of association, though not statistically significant, between nuclear NUAK2 overexpression and poor overall survival rates also existed (p=0.0602). Since NUAK2 is highly overexpressed in ovarian cancer, in vitro functional assays were then performed to determine whether it plays the roles in regulating proliferation and migration of ovarian cancer cells. Cell proliferation was not impeded upon siRNA-mediated knockdown of NUAK2 in OVCAR3 as determined by MTT assay, and Transwell assay showed that ectopic overexpression of NUAK2 in SKOV3 cells had no prominent effect on migration. Together, this study confirmed NUAK2 overexpression in ovarian cancer consistent with the public databases and also postulates the prognostic value of its nuclear form in predicting tumor aggressiveness and disease outcomes of ovarian cancer patients. However, our current study of proliferation and migration in ovarian cancer cells could not address the functional significance of NUAK2 as reflected in its overexpression pattern. It would be important for our future work to identify particular ovarian cancer genotypes that correlate with NUAK2 expression and thereby functionally drive cooperative tumorigenesis together with NUAK2. Citation Format: Li Chen, Oscar Gee-Wan Wong, Ivy Tsz-Lo Wong, Annie Nga-Yin Cheung. NUAK2 is highly overexpressed in ovarian cancer and the overexpression of its nuclear form correlates with tumor 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 5906.

MiR-1231 correlates tumor prognosis and inhibits cell growth in ovarian cancer.

The purpose of this study was to investigate the expression characteristics of miR-1231 in ovarian cancer (OC), and to further explore its effects on cell proliferation capacity of OC cells. Quantitative Real Time-Polymerase Chain Reaction (QRT-PCR) was performed to detect miR-1231 expression in 116 paired of OC and matched adjacent normal tissues. The association of miR-1231 expression and clinicopathological features and prognosis was analyzed. Furthermore, the effects of miR-1231 on cell proliferation and cell cycle of OC cells were evaluated by functional assays. In the study, the results exhibited that miR-1231 expression was lower in ovarian cancer tissues compared with adjacent normal tissues. Lower miR-1231 expression was associated with tumor clinical stage and lymph node invasion in patients. Survival plots by K-M survival analysis showed that lower miR-1231 expression predicted a poor outcome in ovarian cancer patients. Moreover, multivariate analysis implied that miR-1231 expression was an independent maker of overall survival (OS). Functional assays showed that upregulation of miR-1231 expression inhibited cell proliferation and cell cycle progression. We revealed that miR-1231 expression was lower in ovarian cancer tissues cell lines. Lower miR-1231 expression predicted a poor outcome in ovarian cancer patients and upregulation of miR-1231 expression inhibited cell growth.

Abstract B59: Rac1 overexpression promotes epithelial-to-mesenchymal transition in ovarian cancer cells

Abstract The small GTPase Rac1 (Ras-related C3 botulinum toxin substrate 1) is commonly overexpressed in cancer and high Rac1 levels are associated with poor patient outcomes in ovarian cancer. Rac1 drives multiple hallmarks of cancer such as proliferation, quiescence, epithelial-to-mesenchymal transition (EMT), and transcriptional programs relevant to tumor development, progression, and chemoresistance. EMT promotes metastatic dissemination, chemoresistance, and cancer stem cell properties. We find that modest overexpression of Rac1 in ovarian tumor cells causes morphologic changes consistent with EMT. Elevated Rac1 (4- fold) expression decreases colony number and increases colony area when compared to vector control cells. In addition, cell invasion through an artificial basement membrane is increased by 10-fold in cells overexpressing Rac1. An increase in mesenchymal markers (e.g., N-cadherin) and decrease in epithelial markers (e.g., E-cadherin) was observed as a consequence of Rac1 expression. Rac1 overexpression was associated with selective upregulation of Slug/Snai2 (8-fold) and Zeb2 (100-fold) mRNA levels with little impact on Snai1, Twist, or Zeb1. Slug/Snai2 expression is reportedly induced by oxidative stress and treatment of six ovarian tumor cell lines with tert-butyl hydroperoxide (TBHP) to generate oxidative stress increased the expression Slug/Snai2, Snai1, and heme oxygenase-1, an indicator of oxidative stress response. This finding confirms that elevated oxidative stress regulates certain EMT transcription factors in various ovarian cancer cells. Rac1 is an essential factor for activation of NADPH oxidases 1, 2, and 3 and generation of reactive oxygen species (ROS). Basal level of ROS was elevated in cells overexpressing Rac1 compared to vector control cells as detected by the fluorescent probe Dihydroethidium (DHE). Similarly, elevated Rac1 increased expression of the oxidative stress response genes heme oxygenase-1 (17-fold) and superoxide dismutase-1 (12-fold), further supporting that Rac1 stimulated ROS signaling in these cells. We further tested the impact of Rac1 inhibition in vivo using R-ketorolac. Analysis of tumor tissue from mice showed decreased expression of heme-oxygenase-1 and Slug/Snai2 in mice treated with R-ketorolac compared to placebo controls. R-ketorolac also decreased invasive implantation and expansion of ovarian cancer xenografts. Taken together, these findings illustrate the functional impact of Rac1 overexpression in ovarian cancer cells and suggest that Rac1 may be a viable target for further drug development to attenuate EMT in ovarian tumors. Citation Format: Martha M. Grimes, Dayna R. Dominquez, Michaela L. Granados, Alejandra Rosales, Melanie Rivera, Angela Wandinger-Ness, Laurie G. Hudson. Rac1 overexpression promotes epithelial-to-mesenchymal transition in ovarian cancer cells [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B59.

Enlarged cardiophrenic lymph nodes predict disease involvement of the upper abdomen and the outcome of primary surgical debulking in advanced ovarian cancer.

IntroductionThe outcome of ovarian cancer patients is highly dependent on the success of primary debulking surgery in terms of postoperative residual disease. This study critically evaluates the clinical impact of preoperative radiologic assessment of the cardiophrenic lymph node (CPLN) status in advanced ovarian cancer.Material and methodsBaseline CT scans of 178 stage III and IV ovarian cancer patients were retrospectively reviewed by two independent radiologists. CPLN enlargement defined at a short‐axis ≥5 mm was evaluated for its prognostic value and predictive power of upper abdominal tumor involvement and the chance of complete intra‐abdominal tumor resection at primary debulking surgery. Only patients without surgically removed CPLN were eligible for this study.ResultsEnlarged CPLNs were detected in 50% of patients and correlated with radiologically suspicious (P = .028) and histologically confirmed (P = .001) paraaortic lymph node metastases. CPLNs ≥ 5 mm were associated with high CA‐125 levels at baseline and revealed independent prognostic relevance for progression‐free survival (hazard ratio [HR] 2.14, 95% confidence interval [CI] 1.33‐3.42) and overall survival (HR 2.18, 95% CI 1.16‐4.08). Noteworthy, patients with enlarged CPLNs nonetheless benefit from complete intra‐abdominal tumor debulking in terms of an improvement in progression‐free survival (HR 0.60, 95% CI 0.38‐0.94) and overall survival (HR 0.59, 95% CI 0.35‐0.82). Enlarged CPLNs correctly predicted carcinomatosis of the upper abdomen in 94.6%. A predictive score of complete tumor debulking, termed CD‐score, which integrates, beside a CPLN short axis <5 mm, an ascites volume <500 mL, and CA‐125 levels <500 U/mL at baseline, correctly predicted complete intra‐abdominal debulking in 100% of patients.ConclusionsCPLNs ≥5 mm predict upper abdominal tumor involvement. The application of the CD‐score predicted complete macroscopic tumor resection at primary surgery in all of the patients. Although, CPLN pathology suggests extra‐abdominal disease, we consistently demonstrated that patients nonetheless benefit from complete intra‐abdominal tumor resection.

Subcellular localization of FANCD2 is associated with survival in ovarian carcinoma.

Objective: Ovarian cancer is a leading cause of death from gynecological cancers. Late diagnosis and resistance to therapy results in mortality and effective screening is required for early diagnosis and better treatments. Expression of the Fanconi Anemia complementation group D2 protein (FANCD2) is reduced in ovarian surface epithelial cells (OSE) in patients with ovarian cancer. FANCD2 has been studied for its role in DNA repair; however multiple studies have suggested that FANCD2 has a role outside the nucleus. We sought to determine whether subcellular localization of FANCD2 correlates with patient outcome in ovarian cancer.Methods: We examined the subcellular localization of FANCD2 in primary OSE cells from consenting patients with ovarian cancer or a normal ovary. Ovarian tissue microarray was stained with anti-FANCD2 antibody by immunohistochemistry and the correlation of FANCD2 localization with patient outcomes was assessed. FANCD2 binding partners were identified by immunoprecipitation of cytoplasmic FANCD2.Results: Nuclear and cytoplasmic localization of FANCD2 was observed in OSEs from both normal and ovarian cancer patients. Patients with cytoplasmic localization of FANCD2 (cFANCD2) experienced significantly longer median survival time (50 months), versus patients without cytoplasmic localization of FANCD2 (38 months; p < 0.05). Cytoplasmic FANCD2 was found to bind proteins involved in the innate immune system, cellular response to heat stress, amyloid fiber formation and estrogen mediated signaling.Conclusions: Our results suggest that the presence of cytoplasmic FANCD2 modulates FANCD2 activity resulting in better survival outcome in ovarian cancer patients.

Clinical significance of PI3 and HLA-DOB as potential prognostic predicators for ovarian cancer.

BackgroundThe outcomes of ovarian cancer patients are very poor, therefore it is necessary to find prognostic biomarkers and explore the potential underlying molecular mechanisms of ovarian cancer.MethodsIn this study, a gene expression microarray data set covering 562 ovarian serous cystadenocarcinomas and 12,042 genes was downloaded from The Cancer Genome Atlas (TCGA) database. For each candidate gene, samples were allocated into a “high group” or a “low group” according to the expression level. The overall survival (OS) rates were compared between the two groups. Then, a univariate analysis and a multivariate Cox proportional hazards test were carried out to examine the associations between genes and multiple clinicopathological parameters.ResultsAmong all candidate genes, PI3 (peptidase inhibitor 3, often called elafin) and HLA-DOB (major histocompatibility complex, class II, DO beta) were identified as hub genes. PI3 (P=7.99e-7) and HLA-DOB (P=7.52e-6) showed significant associations with OS, especially in patients with stage III or IV disease. Both PI3 (HR =1.84, P=3.77e-7) and HLA-DOB (HR =0.68, P=0.001134) were identified as independent predictors of ovarian cancer patients OS. In addition, IRF1 (interferon regulatory factor 1) (P=1.16e-15) and SPI1 (Spi-1 proto-oncogene) (P=2.03e-6) were identified as the most significant transcription factors.ConclusionsOur data indicate that PI3 and HLA-DOB are potential biomarkers that could be used to predict the prognosis of ovarian cancer patients, and may play important roles in ovarian cancer progression. Further experimental and clinical studies with larger sample sizes are needed to confirm these findings.

Sarcopenic Factors May Have No Impact on Outcomes in Ovarian Cancer Patients.

Although the prognostic value of sarcopenic factors, such as loss of muscle mass and quality, have been widely reported in patients with cancer during the last decade, the value in those with ovarian cancer remains unclear. Therefore, this study evaluated the prognostic impact of sarcopenic factors in patients with ovarian cancer. We retrospectively evaluated the data of 94 ovarian cancer patients who underwent surgery and chemotherapy at the Shimane University Hospital between March 2006 and 2013. Preoperative computed tomography scan at the level of the third lumbar vertebra was used to evaluate skeletal muscle volume and quality based on the skeletal muscle index (SMI) and intramuscular adipose tissue content (IMAC), respectively. The impact of preoperative SMI and IMAC on outcomes was subsequently investigated. Low SMI and high IMAC were not significantly associated with disease-free survival (p = 0.329 and p = 0.3370, respectively) or poor overall survival (p = 0.921 and p = 0.988, respectively). Neither preoperative low muscle volume nor low muscle quality was a poor prognostic factor in ovarian cancer.

Upregulated LINC00565 Accelerates Ovarian Cancer Progression By Targeting GAS6.

BackgroundLong noncoding RNAs (lncRNAs) have been identified to participate in tumorigenesis. However, the underlying mechanisms of differentially expressed lncRNAs engaged in diseases remain indistinct and need further exploration.MethodsRaw data files downloaded from TCGA and GEO dataset were used to analyze the differentially expressed lncRNAs and LINC00565 was picked out as the potential oncogene. qRT-PCR was used to analyze the LINC00565 level in ovarian tissues and cell lines. Subsequently, the selected ovarian tumor cells were then transfected with LINC00565 siRNA by Lipofectamine 2000 and the cell cycle was detected by flow cytometry. Effect of LINC00565 on tumor growth and cell cycle was verified by tumor formation assay in nude mice. The mechanism of LINC00565 involving in cell cycle regulation was further explored by Western blot.ResultsIn this research, we discovered that LINC00565, a novel lncRNA, was highly expressed in ovarian cancer (OC). LINC00565 expression level was negatively associated with outcomes of OC patients. Further analysis showed that LINC00565 expression was closely correlated to tumor size, FIGO stage, but not related to other clinical features. In vitro experiments indicated that knockdown of LINC00565 significantly inhibited proliferative, invasive and migratory abilities of ovarian cancer cells. Besides, knockdown of LINC00565 can induce cell cycle arrest in G0/G1 phase. In addition, in vivo assay showed that low expression of LINC00565 inhibited the growth of OC. Further study found that LINC00565 knockdown markedly downregulated the protein expressions of CyclinD1, CyclinE1 and CDK4, but upregulated the expression of P16 and P21. Subsequently, we confirmed that LINC00565 promoted the progression of OC via upregulating GAS6, which has been confirmed to promote tumor progression.ConclusionIn summary, our study firstly reported that the LINC00565 functioned as an oncogene to promote the progression of OC by interacting with GAS6.

Sarcopenia in Ovarian Cancer Patients, Oncologic Outcomes Revealing the Importance of Clinical Nutrition: Review of Literature.

Ovarian cancer is the leading cause of death among gynecological malignancies. Its usual clinical manifestation is at advanced stages, with nutritional impairment, weight loss, and a consequent decline in skeletal muscle mass and strength (defined as sarcopenia). The relationship between sarcopenia and decreased survival was demonstrated not only in ovarian cancer but also in other cancer types, such as hepatocellular, pancreatic, lung, colon, cervical, metastatic breast, and renal cancer. The aim of this study is to review the current evidence regarding the relationship between sarcopenia and the surgical and oncological outcomes in ovarian cancer patients. The systematic search was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRSIMA) statement. The terms "SARCOPENIA" AND "OVARIAN CANCER" were systematically used to search PubMed and Scopus databases. Original reports in English language were identified, with the purpose to include all relevant papers regarding the role of sarcopenia and indicators of skeletal muscle quality assessment in gynecological ovarian cancer. A total of 9 studies were considered eligible for the present review. The strength of recommendation was moderate and the level of evidence was low in all selected articles. No prospective studies were conducted and most of the papers were case-control series comparing ovarian cancer sarcopenic population vs. non sarcopenic population. Sarcopenia appears to have an important role in oncological outcomes of ovarian cancer patients. However, sarcopenia occurrence during disease history and mechanisms underlying the possible impairment in prognosis should be better investigated. Prospective trials are awaited in order to obtain a better insight in this topic.

Decreased DHRS2 expression is associated with HDACi resistance and poor prognosis in ovarian cancer

ABSTRACTHistone deacetylases (HDACs) have been linked to a variety of cancers, and HDAC inhibitors (HDACi) are a promising class of drugs that have demonstrated anti-cancer effects. However, we have little knowledge regarding the selection and application of HDAC inhibitors to the personalized treatment of ovarian cancer (OC). Here, we report a correlation between the high expression of HDACs and poor outcomes in OC patients, which reveals that HDACi are a class of agents that show great promise for the treatment of OC. Furthermore, we found that HDACi increased both the mRNA and protein levels of DHRS2, which has been shown to be closely linked to HDACi sensitivity when it is highly expressed, especially in ovarian cancer cells. Consistently, we found that suppression of DHRS2 reduced the sensitivity of OC cells to HDAC inhibitors via attenuation of the inhibitory effects of HDAC inhibitors on Mcl-1 in vitro. Our study demonstrated that DHRS2 expression was decreased in OC tissues and that high expression of DHRS2 was correlated with better outcomes in OC patients. In addition, DHRS2 expression was closely related to the effects of chemotherapy. Our study reveals the role of DHRS2 in cell apoptosis induced by HDAC inhibitors and explores the clinical attributes of DHRS2 in OC from a new perspective, suggesting that OC patients with high DHRS2 expression may benefit from treatment with HDAC inhibitors.

Survival outcomes of ovarian cancer patients treated with secondary cytoreductive surgery for isolated lymph node recurrence: A systematic review of the literature.

Isolated lymph node recurrence (ILNR) is present in 12-37% of recurrences in ovarian cancer patients. Although several studies have investigated the impact of secondary cytoreduction in these cases, consensus still lacks concerning their optimal management. The purpose of the present review is to investigate whether secondary cytoreduction benefits patients with ILNR in terms of overall survival (OS) and post-relapse survival (PRS). The present systematic review was designed using the PRISMA and AMSTAR guidelines and has been registered with PROSPERO (CRD42019122854). We searched Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL and Google Scholar databases from inception until February 2019. Overall, eight studies where included that recruited a total number of 479 women. Current evidence suggests that ILNR in EOC patients should be clearly distinguished from recurrences in other sites (including peritoneal and parenchymal) as their course seems to be less aggressive. Furthermore, the implementation of secondary cytoreduction as an adjunct to standard chemotherapy should be taken into consideration in this specific group of patients as the PRS may easily reach and even extend beyond 5 years. Prolonged survival (>110 months) may be seen as a realistic target for a significant number of these patients when systematic lymphadenectomy is performed. The findings of our review suggest that patients with ILNR should be treated with a combined surgical and chemotherapeutic approach to optimize survival outcomes. However, further studies are needed to reach firm conclusions as current evidence is based in low quality studies.

Clinical outcomes in ovarian cancer patients receiving three versus more cycles of chemotherapy after neoadjuvant treatment and interval cytoreductive surgery

ObjectivesTo compare clinical outcomes for stage IIIC and IV ovarian cancer patients receiving neoadjuvant chemotherapy and interval cytoreductive surgery followed by up to three versus more cycles of post-operative chemotherapy.MethodsWe...

Oncolytic Maraba virus armed with tumor antigen boosts vaccine priming and reveals diverse therapeutic response patterns when combined with checkpoint blockade in ovarian cancer

BackgroundCancer immunotherapies are emerging as promising treatment strategies for ovarian cancer patients that experience disease relapse following first line therapy. As such, identifying strategies to bolster anti-tumor immunity and limit immune suppression, while recognizing diverse patterns of tumor response to immunotherapy is critical to selecting treatment combinations that lead to durable therapeutic benefit.MethodsUsing a pre-clinical mouse model, we evaluated a heterologous prime/boost vaccine in combination with checkpoint blockade to treat metastatic intraperitoneal ovarian cancer. Vaccine-elicited CD8+ T cell responses and changes in the tumor microenvironment following treatment were analyzed and compared to treatment outcome. Kinetics of intraperitoneal tumor growth were assessed using non-invasive magnetic resonance imaging (MRI).ResultsVaccine priming followed by antigen-armed oncolytic Maraba virus boosting elicited robust tumor-specific CD8+ T cell responses that improved tumor control and led to unique immunological changes in the tumor, including a signature that correlated with improved clinical outcome of ovarian cancer patients. However, this treatment was not curative and T cells in the tumor microenvironment (TME) were functionally suppressed. Combination PD-1 blockade partially overcame the adaptive resistance in the tumor observed in response to prime/boost vaccination, restoring CD8+ T cell function in the TME and enhancing the therapeutic response. Non-invasive MRI of tumors during the course of combination treatment revealed heterogeneous radiologic response patterns following treatment, including pseudo-progression, which was associated with improved tumor control prior to relapse.ConclusionsOur findings point to a key hierarchical role for PD-1 signaling and adaptive immune resistance in the ovarian TME in determining the functional fate of tumor-specific CD8+ T cells, even in the context of robust therapy mediated anti-tumor immunity, as well as the ability of multiple unique patterns of therapeutic response to result in durable tumor control.

Abstract 4768: PARP inhibitor-induced autophagy provides an adaptive mechanism of drug resistance in preclinical models of ovarian cancer

Abstract Poly (ADP) ribose polymerase inhibitors (PARPi) have shown promising activity against recurrent ovarian cancers, particularly in women with germ line mutations of BRCA1/2. The efficacy of PARP inhibitors can, however, be decreased by acquired drug resistance. Autophagy or “self-eating” is one mechanism implicated in cancer progression and therapy resistance. Autophagy is a catabolic mechanism that can degrade organelles and long-lived proteins to provide energy for cancer cells under nutrient poor conditions or in the presence of stress. The energy provided from autophagy is used to fuel the DNA repair process and metabolic needs in cancer cells. Autophagy can protect cancer cells from chemotherapy or can enhance the response to certain drugs. In this study, we have asked whether autophagy contributes to the resistance of ovarian cancer cells to PARPi. Our group has found that four PARP inhibitors (olaparib, niraparib, rucaparib and talazorapib) induce autophagy in 8 ovarian cancer cell lines, detected by LC3A to LC3B conversion on western blot analysis and punctate GFP-LC3 fluorescence. Transmission electron microscopy confirmed the increased autophagosome formation in olaparib treated cells. To test whether autophagy contributes to the resistance of OC cells to olaparib, we determined the impact of autophagy inhibition on the sensitivity of OC cell lines to olaparib by either using chloroquine, hydroxychloroquine or LYS05 to block hydrolysis of proteins and lipids in autophagosomes or using siRNA against ATG5 or ATG7 to prevent formation of autophagosome. Enhancement of PARPi activity was observed in 6 out 8 ovarian cancer cell lines. Moreover, a combination of olaparib and chloroquine proved more effective than either single agent in a xenograft model of the OVCAR8 ovarian cancer cell line and in a patient derived xenograft model. Mechanistically, olaparib decreased PARP activity leading to DNA damage and accumulation of γ-H2AX. Olaparib treatment increased reactive oxygen species (ROS) and phosphorylation of ATM, while decreasing the phosphorylation of AKT and mTOR. We also observed an increase in PTEN, a well-recognized negative regulator of AKT. Inhibition of PTEN decreases LC3 conversion, suggesting PTEN as an important regulator of olaparib-induced autophagy in ovarian cancer cells. Taken together, our data demonstrate for the first time that olaparib induces autophagy in ovarian cancer cells and provides an adaptive mechanism of resistance to PARPi. Olaparib-induced autophagy may depend upon activation of ATM and PTEN by ROS, downregulating pAKT/pmTOR signaling. Moreover we have identify unique combinations of therapy with PARPi and CQ or other inhibitors of autophagy that could improve outcomes for ovarian cancer patients. Citation Format: Janice M. Santiago-O'Farrill, Saravut J. Weroha, Xiaonan Hou, Lan Pang, Philip Rask, Zhen Lu, Robert C. Bast. PARP inhibitor-induced autophagy provides an adaptive mechanism of drug resistance in preclinical models of ovarian cancer [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 4768.

Abstract 2240: Redefining personalized medicine by drug response profiling of patient-derived spheroids

Abstract Personalized medicine in cancer typically refers to the use of genetics and/or biomarkers to direct the use of targeted therapy or predict overall prognosis based on statistical probability. Therapy selection and predictions are not based on any physical interaction between a patient’s tumor cells to clinically relevant therapies based on their disease indication. We have developed an assay using 3D cell culture that exposes a patient’s tumor cells to standard of care chemotherapies for the purpose of predicting their clinical response to potential treatment options prior to treatment. We have analytically validated this assay enabling its performance under CLIA regulations as a Laboratory Developed Test (LDT) and prospectively validated it against clinical patient outcome in ovarian cancer. The test utilizes excess fresh patient tissue acquired during standard of care surgical debulking or biopsy and returns results within 7 business days of tissue receipt, typically well before the start of chemotherapy. Previously, we have shown in newly diagnosed ovarian cancer, the test has an accuracy of 87% with a specificity of 100% and a sensitivity of 84% in the prediction of standard first-line carboplatin/taxol combination therapy using the biomarker CA-125 and CT imaging as clinical readouts. We have similar results for the prediction of response to neoadjuvant therapy following laparoscopic biopsy using RECIST criteria. We have now analytically validated the assay in glioblastoma (GBM) and rare tumors. Preliminary clinical validation in GBM has shown the ability of the test to accurately predict response to standard first-line temozolomide using RANO criteria as the clinical readout. Rare tumor validation has included a panel of 12 drugs covering those used as standard of care for most rare tumors. Aspects of validation have included examining inter- and intra-assay variability and drug panel response in a defined number of rare tumors including sarcomas, neuroendocrine, and other tumors such as Sertoli-Leydig. In breast cancer, we have validated the assay for the use of a single diagnostic biopsy core as the tissue source and established preliminary clinical validation against standard of care such as doxorubicin and paclitaxel with pathologic complete response (pCR) as the clinical readout. We are further validating the predictive ability of the test in newly diagnosed and relapsed ovarian cancer and GBM patients (clinical trial NCT03561207). With demonstrated accurate prediction of patient specific response, the transition to cancer therapy selection based on physical evidence vs statistical probability would significantly improve patient outcomes and benefit economic stakeholders. Citation Format: Stephen Shuford, Christine Wilhelm, Ashley M. Smith, Melissa Rayner, Jeremy Stuart, Lillia Holmes, Matt Gevaert, Howland E. Crosswell, Teresa M. DesRochers. Redefining personalized medicine by drug response profiling of patient-derived spheroids [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 2240.

MiR-211 facilitates platinum chemosensitivity by blocking the DNA damage response (DDR) in ovarian cancer

The DNA damage response (DDR) is one of the most important mechanisms of platinum resistance in ovarian cancer. Some miRNAs have been identified to be involved in the regulatory network of DDR, thus the abnormal expression of miRNAs might affect platinum chemosensitivity in ovarian cancer. In this study, by assessing miRNAs simultaneously targeting a set of DDR genes that exhibited response to platinum, we found that miR-211 inhibited most of those genes, and proposed that miR-211 might affect the sensitivity of ovarian cancer cells to platinum by targeting multiple DDR genes and thereby determine the prognosis of ovarian cancer. To verify the hypothesis, we analyzed the association between miR-211 level and clinical prognosis, assessed the effect of miR-211 on DDR and platinum chemosensitivity, and explored the possible molecular mechanism. We revealed that miR-211 enhanced platinum chemosensitivity and was positively correlated with favorable outcomes in ovarian cancer patients. Many DDR genes including TDP1 were identified as targets of miR-211. In contrast, TDP1 suppressed DNA damage and platinum chemosensitivity. Moreover, the miR-211 level in tissues was shown to be associated with the good outcome of neoadjuvant chemotherapy and negatively correlated with the expression of TDP1. Conclusively, we demonstrated that miR-211 improves the prognosis of ovarian cancer patients by enhancing the chemosensitivity of cancer cells to platinum via inhibiting DDR gene expression, which provides an essential basis to identify novel treatment targets to block DDR effectively and improve chemosensitivity in ovarian cancer.

Survival and clinical outcomes of ovarian cancer patients enrolled in phase I clinical trials.

5559 Background: Ovarian cancer patients who enroll in Phase I clinical trials are typically platinum resistant, heavily pretreated patients with a poor prognosis. Historically, clinical benefit of Phase I trials in this patient population has been uncertain. We assessed prognostic factors and survival in women with recurrent, previously treated ovarian cancer who enrolled in Phase I clinical trials. Methods: We performed a retrospective analysis of all ovarian cancer patients who were treated on Phase I clinical trials from 2008 through 2018 at the University of Colorado Cancer Center. Patient characteristics, treatment-related toxicities and survival data were assessed. Descriptive statistics and Cox proportional hazards models were utilized to identify risk factors associated with survival time. Results: A total of 132 individual patients were treated on Phase I clinical trials. Patients had a median age of 59 years (range 33-88) with a median of 5.5 (range 1-13) previous chemotherapy lines. 53/132 (40%) of patients were treated on multiple Phase I trials with a median of 1 (range 0-5) prior Phase 1 clinical trial enrollments. All patients had an ECOG performance status of 0 or 1. Overall response rate (defined as complete or partial response) was 9% and disease control rate (defined as complete or partial response or stable disease as best response) was 33%. Median overall survival (OS) was 11.5 months (95% CI: 9.3-13.7). Two patients died on trial due to progression of disease while no patients died due to treatment-related toxicity. In multivariate analysis, independent risk factors predicting shorter survival were elevated CA-125 (HR 2.8; 95% CI: 1.6-5.2) and albumin &lt; 3.5 g/dL (HR 2.5; 95% CI: 1.65-3.79). BMI &gt; 25 predicted longer survival (HR 0.65; 95% CI: 0.44-0.96). Conclusions: Phase I clinical trials for heavily pretreated ovarian cancer patients are safe by a standard of no patients experiencing toxicity-related deaths in our study. They are clinically efficacious with patients experiencing OS of 11.5 months, which is comparable to existing approved therapies. Elevated CA-125 and low albumin levels predict shorter survival, while BMI &gt; 25 predicts longer survival. Phase I clinical trial options should be considered for all heavily pretreated ovarian cancer patients if available to them.

ER stress-induced mediator C/EBP homologous protein thwarts effector T\xa0cell 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.

BRCA1-associated and sporadic ovarian carcinomas: outcomes of primary cytoreductive surgery or neoadjuvant chemotherapy.

Tumors arising in BRCA1/2 mutation carriers are characterized by increased platinum sensitivity; however, it is unknown whether this feature should be considered while choosing between primary surgical versus systemic treatment. This study aimed to compare outcomes of ovarian cancer patients undergoing either primary surgery or interval cytoreduction based on BRCA1/2 status. The study included consecutive ovarian cancer patients, who were treated at the N.N. Petrov Institute of Oncology (St Petersburg, Russia) from 2000 to 2013 and who underwent complete or optimal cytoreductive surgery. A comparison of disease outcomes was performed for the total group of ovarian cancer patients as well as for 69 BRCA1-mutated and 151 sporadic high-grade serous advanced-stage ovarian carcinomas. Frequency comparisons were performed by Chi-square test or Fisher exact test. Disease-free interval and overall survival were analyzed by Mann-Whitney U-test and Kaplan-Meier method. Hazard ratios were calculated by Cox regression analysis. The analysis included 283 consecutive patients who underwent optimal cytoreduction (size of residual tumor <1 cm (n=156)) or complete tumor excision (n=127) on primary surgery (n=168) or after neoadjuvant chemotherapy (n=115). 84 patients carried germline mutation in BRCA1 (n=77) or BRCA2 (n=7) genes, while 199 ovarian cancer patients were classified as sporadic. High-grade serous ovarian cancer patients treated with neoadjuvant chemotherapy had a lower disease-free interval compared with those undergoing primary surgery followed by adjuvant therapy (7.8 vs 14.2 months, p<0.001). This difference was attributed mainly to sporadic cases (5.1 vs 12.2 months, p<0.001), while BRCA1-associated cancers had a similar disease-free interval regardless of the sequence of treatments (12.5 vs 15.8 months, p=0.53). When treated with neoadjuvant chemotherapy, BRCA1-mutated patients had improved overall survival as compared with sporadic cases (45.7 vs 25.3 months, p=0.007), while patients subjected to primary surgery showed similar overall survival irrespective of BRCA1 status (54.6 vs 53.9 months, p=0.56). A total of 29/61 (48%) BRCA1/2-associated patients relapsed as a single local tumor; this was lower in sporadic cancer patients (38/134 (28%); p=0.01). In BRCA1 mutation carriers, the oncologic outcomes are similar when comparing primary surgery versus neoadjuvant chemotherapy. In addition, BRCA1-mutation carriers often have a single site of disease when diagnosed with recurrent ovarian cancer.

A novel L1CAM isoform with angiogenic activity generated by NOVA2-mediated alternative splicing.

The biological players involved in angiogenesis are only partially defined. Here, we report that endothelial cells (ECs) express a novel isoform of the cell-surface adhesion molecule L1CAM, termed L1-ΔTM. The splicing factor NOVA2, which binds directly to L1CAM pre-mRNA, is necessary and sufficient for the skipping of L1CAM transmembrane domain in ECs, leading to the release of soluble L1-ΔTM. The latter exerts high angiogenic function through both autocrine and paracrine activities. Mechanistically, L1-ΔTM-induced angiogenesis requires fibroblast growth factor receptor-1 signaling, implying a crosstalk between the two molecules. NOVA2 and L1-ΔTM are overexpressed in the vasculature of ovarian cancer, where L1-ΔTM levels correlate with tumor vascularization, supporting the involvement of NOVA2-mediated L1-ΔTM production in tumor angiogenesis. Finally, high NOVA2 expression is associated with poor outcome in ovarian cancer patients. Our results point to L1-ΔTM as a novel, EC-derived angiogenic factor which may represent a target for innovative antiangiogenic therapies.