Molecular Analysis of Short- versus Long-Term Survivors of High-Grade Serous Ovarian Carcinoma

Cancers (Basel). 2022 Aug 30;14(17):4198. doi: 10.3390/cancers14174198.

Abstract

Despite having similar histologic features, patients with high-grade serous ovarian carcinoma (HGSC) often experience highly variable outcomes. The underlying determinants for long-term survival (LTS, ≥10 years) versus short-term survival (STS, <3 years) are largely unknown. The present study sought to identify molecular predictors of LTS for women with HGSC. A cohort of 24 frozen HGSC samples was collected (12 LTS and 12 STS) and analyzed at DNA, RNA, and protein levels. OVCAR5 and OVCAR8 cell lines were used for in vitro validation studies. For in vivo studies, we injected OVCAR8 cells into the peritoneal cavity of female athymic nude mice. From RNAseq analysis, 11 genes were found to be differentially expressed between the STS and LTS groups (fold change > 2; false discovery rate < 0.01). In the subsequent validation cohort, transmembrane protein 62 (TMEM62) was found to be related to LTS. CIBERSORT analysis showed that T cells (follicular helper) were found at higher levels in tumors from LTS than STS groups. In vitro data using OVCAR5 and OVCAR8 cells showed decreased proliferation with TMEM62 overexpression and positive correlation with a longevity-regulating pathway (KEGG HSA04213) at the RNA level. In vivo analysis using the OVCAR8-TMEM62-TetON model showed decreased tumor burden in mice with high- vs. low-expressing TMEM62 tumors. Our results demonstrate that restoring TMEM62 may be a novel approach for treatment of HGSC. These findings may have implications for biomarker and intervention strategies to help improve patient outcomes

Keywords: HGSC; TMEM62; long-term survival; ovarian cancer; short-term survival.

Grants and funding

Funding for this research was provided by the U.S. Department of Defense (DoD) and grants R35 CA209904 and U01 CA213759; by the American Cancer Society; and by the Frank McGraw Memorial Chair in Cancer Research). E.S. is supported by Ovarian Cancer Research Alliance (OCRA number FP00006137). S.Y.W. was supported by Ovarian Cancer Research Fund Alliance, Foundation for Women’s Cancer, Texas Center for Cancer Nanomedicine, and Cancer Prevention Research Institute of Texas training grants (RP101502 and RP101489). H.C. was supported by a Computational Cancer Biology Training Program fellowship on CPRIT RP170593. Part of this research was performed in the Flow Cytometry & Cellular Imaging Core Facility (supported in part by the National Institutes of Health through MD Anderson’s Cancer Center Support Grant CA016672, the NCI’s Research Specialist 1 R50 CA243707-01A1).