A Unique Pattern of Mesothelial-Mesenchymal Transition Induced in the Normal Peritoneal Mesothelium by High-Grade Serous Ovarian Cancer

The study was designed to establish whether high aggressiveness of high-grade serous ovarian cancer cells (HGSOCs), which display rapid growth, advanced stage at diagnosis and the highest mortality among all epithelial ovarian cancer histotypes, may be linked with a specific pattern of mesothelial-mesenchymal transition (MMT) elicited by these cells in normal peritoneal mesothelial cells (PMCs). Experiments were performed on primary PMCs, stable and primary ovarian cancer cells, tumors from patients with ovarian cancer, and laboratory animals. Results of in vitro and in vivo tests showed that MMT triggered by HGSOCs (primary cells and OVCAR-3 line) is far more pronounced than the process evoked by cells representing less aggressive ovarian cancer histotypes (A2780, SKOV-3). Mechanistically, HGSOCs induce MMT via Smad 2/3, ILK, TGF-β1, HGF, and IGF-1, whereas A2780 and SKOV-3 cells via exclusively Smad 2/3 and HGF. The conditioned medium from PMCs undergoing MMT promoted the progression of cancer cells and the effects exerted by the cells triggered to undergo MMT by the HGSOCs were significantly stronger than those related to the activity of their less aggressive counterparts. Our findings indicate that MMT in PMCs provoked by HGSOCs is stronger, proceeds via different mechanisms and has more procancerous characteristics than MMT provoked by less aggressive cancer histotypes, which may at least partly explain high aggressiveness of HGSOCs.

Download Full-text

SPR965, a Dual PI3K/mTOR Inhibitor, as a Targeted Therapy in Ovarian Cancer

Frontiers in Oncology ◽

10.3389/fonc.2020.624498 ◽

2021 ◽

Vol 10 ◽

Author(s):

Arthur-Quan Tran ◽

Stephanie A. Sullivan ◽

Leo Li-Ying Chan ◽

Yajie Yin ◽

Wenchuan Sun ◽

...

Keyword(s):

Ovarian Cancer ◽

Tumor Growth ◽

Cancer Cells ◽

Epithelial Mesenchymal Transition ◽

Transition Process ◽

Ovarian Cancer Cells ◽

Serous Ovarian Cancer ◽

Mesenchymal Transition

SPR965 is an inhibitor of PI3K and mTOR C1/C2 and has demonstrated anti-tumorigenic activity in a variety of solid tumors. We sought to determine the effects of SPR965 on cell proliferation and tumor growth in human serous ovarian cancer cell lines and a transgenic mouse model of high grade serous ovarian cancer (KpB model) and identify the underlying mechanisms by which SPR965 inhibits cell and tumor growth. SPR965 showed marked anti-proliferative activity by causing cell cycle arrest and inducing cellular stress in ovarian cancer cells. Treatment with SPR965 significantly inhibited tumor growth in KpB mice, accompanied by downregulation of Ki67 and VEGF and upregulation of Bip expression in ovarian tumors. SPR965 also inhibited adhesion and invasion through induction of the epithelial–mesenchymal transition process. As expected, downregulation of phosphorylation of AKT and S6 was observed in SPR965-treated ovarian cancer cells and tumors. Our results suggest that SPR965 has significant anti-tumorigenic effects in serous ovarian cancer in vitro and in vivo. Thus, SPR965 should be evaluated as a promising targeted agent in future clinical trials of ovarian cancer.

Download Full-text

Combining ReACp53 with Carboplatin to Target High-Grade Serous Ovarian Cancers

Cancers ◽

10.3390/cancers13235908 ◽

2021 ◽

Vol 13 (23) ◽

pp. 5908

Author(s):

Adam Neal ◽

Tiffany Lai ◽

Tanya Singh ◽

Neela Rahseparian ◽

Tristan Grogan ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Synergistic Effects ◽

Ovarian Cancer Cells ◽

High Grade ◽

Ovarian Carcinomas ◽

Ovarian Cancer Cell Lines ◽

Poor Outcomes

Ovarian malignancies are a leading cause of cancer-related death for US women. High-grade serous ovarian carcinomas (HGSOCs), the most common ovarian cancer subtype, are aggressive tumors with poor outcomes. Mutations in TP53 are common in HGSOCs, with a subset resulting in p53 aggregation and misregulation. ReACp53 is a peptide designed to inhibit mutant p53 aggregation and has been shown efficacious in targeting cancer cells in vitro and in vivo. As p53 regulates apoptosis, combining ReACp53 with carboplatin represents a logical therapeutic strategy. The efficacy of this combinatorial approach was tested in eight ovarian cancer cell lines and 10 patient HGSOC samples using an in vitro organoid drug assay, with the SynergyFinder tool utilized for calculating drug interactions. Results demonstrate that the addition of ReACp53 to carboplatin enhanced tumor cell targeting in the majority of samples tested, with synergistic effects measured in 2 samples, additivity measured in 14 samples, and antagonism measured in 1 sample. This combination was found to be synergistic in OVCAR3 ovarian cancer cells in vitro through enhanced apoptosis, and survival of mice bearing OVCAR3 intraperitoneal xenografts was extended when treated with the addition of ReACp53 to carboplatin versus carboplatin alone. Results suggest that carboplatin and ReACp53 may be a potential strategy in targeting a subset of HGSOCs.

Download Full-text

Anti-Tumor and Anti-Invasive Effects of ONC201 on Ovarian Cancer Cells and a Transgenic Mouse Model of Serous Ovarian Cancer

10.21203/rs.3.rs-152449/v1 ◽

2021 ◽

Author(s):

Yali Fan ◽

Jiandong Wang ◽

Ziwei Fang ◽

Stuart R Pierce ◽

Lindsay West ◽

...

Keyword(s):

Ovarian Cancer ◽

Mouse Model ◽

Tumor Growth ◽

Cancer Cells ◽

Epithelial Mesenchymal Transition ◽

Cellular Stress ◽

Ovarian Cancer Cells ◽

High Grade ◽

Serous Ovarian Cancer ◽

Mesenchymal Transition

Abstract Background: ONC201 is a promising first-in-class small molecule that has been reported to have anti-neoplastic activity in various types of cancer through activation of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as well as activation of mitochondrial caseinolytic protease P (ClpP).Methods: Our objective was to evaluate the effect of the ONC201 on (1) proliferation, cellular stress, apoptosis and invasion in human serous ovarian cancer (OC) cell lines, and (2) inhibition of tumor growth in a genetically engineered mouse model of high grade serous OC (K18-gT121+/-;p53fl/fl;Brca1fl/fl; KpB) under obese (high fat diet) and lean (low fat diet) conditions. Results: ONC201 significantly suppressed cell proliferation, induced arrest in G1 phase, and increased cellular stress and apoptosis, accompanied by dual inhibition of the AKT/mTOR/S6 and MAPK pathways in OC cells. ONC201 also resulted in inhibition of adhesion and invasion via epithelial–mesenchymal transition and reduction of VEGF expression. Pre-treatment with the anti-oxidant, N-acetylcysteine (NAC), reversed the ONC201-induced oxidative stress response, and prevented ONC201-reduced VEGF and cell invasion by regulating epithelial–mesenchymal transition protein expression. Knockdown of ClpP in ovarian cancer cells reduced ONC201 mediated the anti-tumor activity and cellular stress. Diet-induced obesity accelerated ovarian tumor growth in the KpB mouse model. ONC201 significantly suppressed tumor growth, and decreased serum VEGF production in obese and lean mice, leading to a decrease in tumoral expression of Ki-67, VEGF and phosphorylation of p42/44 and S6 and an increase in ClpP and DRD5, as assessed by immunohistochemistry. Additionally, ONC201 exhibited greater anti-tumor efficacy in obese (75%) as compared to lean (65%) mice. InterpretationConclusions: These results suggest that ONC206 may be a promising therapeutic agent to be explored in future clinical trials in high grade serous OC.

Download Full-text

Abstract 323: High grade serous ovarian cancer cells spontaneously self-organize in vitro into multicellular irregular aggregates and highly organized spheroids.

10.1158/1538-7445.am2013-323 ◽

2013 ◽

Author(s):

Alicia A. Goyeneche

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Ovarian Cancer Cells ◽

High Grade ◽

Serous Ovarian Cancer

Download Full-text

Reduced Gonadotrophin Receptor Expression Is Associated with a More Aggressive Ovarian Cancer Phenotype

International Journal of Molecular Sciences ◽

10.3390/ijms22010071 ◽

2020 ◽

Vol 22 (1) ◽

pp. 71

Author(s):

Janelle Cheung ◽

Noor A. Lokman ◽

Riya D. Abraham ◽

Anne M. Macpherson ◽

Eunice Lee ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Cancer Progression ◽

Progression Free Survival ◽

Receptor Expression ◽

Ovarian Cancer Cells ◽

High Grade ◽

Serous Ovarian Cancer ◽

Cancer Phenotype

Follicle-stimulating hormone (FSH) and luteinising hormone (LH) play important roles in regulating cell growth and proliferation in the ovary. However, few studies have explored the expression of FSH and LH receptors (FSHR and LHCGR) in ovarian cancer, and their functional roles in cancer progression remain inconclusive. This study investigated the potential impact of both mRNA (FSHR, LHCGR) and protein (FSHR, LHCGR) expression on ovarian cancer progression using publicly available online databases, qRT-PCR (high grade serous ovarian cancers, HGSOC, n = 29 and benign ovarian tumors, n = 17) and immunohistochemistry (HGSOC, n = 144). In addition, we investigated the effect of FSHR and LHCGR siRNA knockdown on the pro-metastatic behavior of serous ovarian cancer cells in vitro. High FSHR or high LHCGR expression in patients with all subtypes of high-grade ovarian cancer was significantly associated with longer progression-free survival (PFS) and overall survival (OS). High FSHR protein expression was associated with increased PFS (p = 0.050) and OS (p = 0.025). HGSOC patients with both high FSHR and high LHCGR protein levels had the best survival outcome, whilst both low FSHR and low LHCGR expression was associated with poorest survival (p = 0.019). Knockdown of FSHR significantly increased the invasion of serous ovarian cancer cells (OVCAR3 and COV362) in vitro. LHCGR knockdown also promoted invasion of COV362 cells. This study highlights that lower FSHR and LHCGR expression is associated with a more aggressive epithelial ovarian cancer phenotype and promotes pro-metastatic behaviour.

Download Full-text

Exosomes in ovarian cancer ascites promote epithelial–mesenchymal transition of ovarian cancer cells by delivery of miR-6780b-5p

Cell Death and Disease ◽

10.1038/s41419-021-03490-5 ◽

2021 ◽

Vol 12 (2) ◽

Author(s):

Jing Cai ◽

Lanqing Gong ◽

Guodong Li ◽

Jing Guo ◽

Xiaoqing Yi ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Tumor Metastasis ◽

Cancer Metastasis ◽

Epithelial Mesenchymal Transition ◽

Ovarian Cancer Cells ◽

Specific Mechanism ◽

Mesenchymal Transition

AbstractThe poor prognosis of ovarian cancer is mainly due to metastasis, and the specific mechanism underlying ovarian cancer metastasis is not clear. Ascites-derived exosomes (ADEs) play an important role in the progression of ovarian cancer, but the mechanism is unknown. Here, we found that ADEs promoted ovarian cancer metastasis not only in vitro but also in vivo. This promotive function was based on epithelial–mesenchymal transition (EMT) of ovarian cancer cells. Bioinformatics analysis of RNA sequencing microarray data indicated that miR-6780b-5p may be the key microRNA (miRNA) in ADEs that facilitates cancer metastasis. Moreover, the expression of exosomal miR-6780b-5p correlated with tumor metastasis in ovarian cancer patients. miR-6780b-5p overexpression promoted and miR-6780b-5p downregulation suppressed EMT of ovarian cancer cells. These results suggest that ADEs transfer miR-6780b-5p to ovarian cancer cells, promoting EMT and finally facilitating ovarian cancer metastasis.

Download Full-text

Primary high-grade serous ovarian cancer cells are sensitive to senescence induced by carboplatin and paclitaxel in vitro

Cellular & Molecular Biology Letters ◽

10.1186/s11658-021-00287-4 ◽

2021 ◽

Vol 26 (1) ◽

Author(s):

Paweł Uruski ◽

Agnieszka Sepetowska ◽

Corinna Konieczna ◽

Martyna Pakuła ◽

Michał Wyrwa ◽

...

Keyword(s):

Cell Cycle ◽

Ovarian Cancer ◽

Dna Damage ◽

Cancer Cells ◽

Telomere Length ◽

Telomerase Activity ◽

Ovarian Cancer Cells ◽

High Grade ◽

Serous Ovarian Cancer

Abstract Background Various types of normal and cancer cells undergo senescence in response to carboplatin and paclitaxel, which are considered the gold standard treatments in ovarian cancer management. Surprisingly, the effect of these drugs on ovarian cancer cell senescence remained unknown. Methods The experiments were conducted on primary high-grade serous ovarian cancer cells. Molecular markers of senescence were evaluated using cytochemistry and immunofluorescence. Cell cycle distribution was analyzed using flow cytometry. Expression of cyclins and signaling pathways was tested using western blot. Telomere length and telomerase activity were measured using qPCR, and the colocalization of telomeres with DNA damage foci using immuno-FISH. Oxidative stress-related parameters were quantified using appropriate fluorescence probes. Production of cancerogenic agents was analyzed using qPCR and ELISA. Results Carboplatin applied with paclitaxel induces senescence of ovarian cancer cells in vitro. This activity was reflected by permanent G2/M growth arrest, a high fraction of cells expressing senescence biomarkers (SA-β-Gal and γ-H2A.X), upregulated expression of p16, p21, and p53 cell cycle inhibitors, and decreased expression of cyclin B1. Neither telomere length nor telomerase activity changed in the senescent cells, and the majority of DNA damage was localized outside telomeres. Moreover, drug-treated cancer cells exhibited increased production of STAT3 protein, overproduced superoxide and peroxides, and increased mitochondrial mass. They were also characterized by upregulated ANG1, CCL11, IL-6, PDGF-D, TIMP-3, TSP-1, and TGF-β1 at the mRNA and/or protein level. Conclusions Our findings imply that conventional chemotherapy may elicit senescence in ovarian cancer cells, which may translate to the development of a cancer-promoting phenotype, despite the inability of these cells to divide.

Download Full-text

Plasma cells shape the mesenchymal identity of ovarian cancers through transfer of exosome-derived microRNAs

Science Advances ◽

10.1126/sciadv.abb0737 ◽

2021 ◽

Vol 7 (9) ◽

pp. eabb0737

Author(s):

Zhengnan Yang ◽

Wei Wang ◽

Linjie Zhao ◽

Xin Wang ◽

Ryan C. Gimple ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Plasma Cell ◽

Plasma Cells ◽

Ovarian Cancer Cells ◽

Mesenchymal Phenotype ◽

Ovarian Cancers ◽

Novel Approach

Ovarian cancer represents a highly lethal disease that poses a substantial burden for females, with four main molecular subtypes carrying distinct clinical outcomes. Here, we demonstrated that plasma cells, a subset of antibody-producing B cells, were enriched in the mesenchymal subtype of high-grade serous ovarian cancers (HGSCs). Plasma cell abundance correlated with the density of mesenchymal cells in clinical specimens of HGSCs. Coculture of nonmesenchymal ovarian cancer cells and plasma cells induced a mesenchymal phenotype of tumor cells in vitro and in vivo. Phenotypic switch was mediated by the transfer of plasma cell–derived exosomes containing miR-330-3p into nonmesenchymal ovarian cancer cells. Exosome-derived miR-330-3p increased expression of junctional adhesion molecule B in a noncanonical fashion. Depletion of plasma cells by bortezomib reversed the mesenchymal characteristics of ovarian cancer and inhibited in vivo tumor growth. Collectively, our work suggests targeting plasma cells may be a novel approach for ovarian cancer therapy.

Download Full-text

Splicing factor USP39 promotes ovarian cancer malignancy through maintaining efficient splicing of oncogenic HMGA2

Cell Death and Disease ◽

10.1038/s41419-021-03581-3 ◽

2021 ◽

Vol 12 (4) ◽

Author(s):

Shourong Wang ◽

Zixiang Wang ◽

Jieyin Li ◽

Junchao Qin ◽

Jianping Song ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Malignant Tumors ◽

Splicing Factor ◽

Ovarian Cancer Cells ◽

Nuclear Speckles ◽

Aberrant Expression ◽

Intergenic Regions

AbstractAberrant expression of splicing factors was found to promote tumorigenesis and the development of human malignant tumors. Nevertheless, the underlying mechanisms and functional relevance remain elusive. We here show that USP39, a component of the spliceosome, is frequently overexpressed in high-grade serous ovarian carcinoma (HGSOC) and that an elevated level of USP39 is associated with a poor prognosis. USP39 promotes proliferation/invasion in vitro and tumor growth in vivo. Importantly, USP39 was transcriptionally activated by the oncogene protein c-MYC in ovarian cancer cells. We further demonstrated that USP39 colocalizes with spliceosome components in nuclear speckles. Transcriptomic analysis revealed that USP39 deletion led to globally impaired splicing that is characterized by skipped exons and overrepresentation of introns and intergenic regions. Furthermore, RNA immunoprecipitation sequencing showed that USP39 preferentially binds to exon-intron regions near 5′ and 3′ splicing sites. In particular, USP39 facilitates efficient splicing of HMGA2 and thereby increases the malignancy of ovarian cancer cells. Taken together, our results indicate that USP39 functions as an oncogenic splicing factor in ovarian cancer and represents a potential target for ovarian cancer therapy.

Download Full-text