Oleanolic Acid (OA) Targeting UNC5B Inhibits Proliferation and EMT of Ovarian Cancer Cell and Increases Chemotherapy Sensitivity of Niraparib

Objective. To investigate the effect of OA on proliferation, migration, and epithelial-mesenchymal transition (EMT) of ovarian cancer cells by inhibiting UNC5B and to study its mechanism. Methods. TCGA database was used to analyze the expression of UNC5B in ovarian cancer and its relationship with prognosis. The expression of UNC5B in ovarian cancer cells was detected by qPCR assay. qRT-PCR was used to detect the changes of EMT markers after different treatments. CCK-8 assay was used to detect cell proliferation, transwell assay was used to evaluate cell migration, and clonogenesis assay was used to evaluate the effect of UNC5B on ovarian cancer cell proliferation. Meanwhile, the synergistic effect of OA on niraparib was evaluated. Results. UNC5B was highly expressed in ovarian cancer, and its expression was negatively correlated with the prognosis of ovarian cancer patients. UNC5B was highly expressed in ovarian cancer cells SKOV3 and OVCA420 compared with normal ovarian epithelial cells. In addition, silencing UNC5B inhibits the proliferation, invasion, clonogenesis, and EMT processes of ovarian cancer cells. OA inhibits proliferation, invasion, and clonogenesis of ovarian cancer cells by inhibiting UNC5B and increases the antitumor activity of niraparib. Conclusion. UNC5B acts as an oncogenic gene in ovarian cancer. OA inhibits ovarian cancer cell proliferation, migration, and EMT by targeting UNC5B and increases the antitumor effect of niraparib. UNC5B is expected to be a new potential therapeutic target for ovarian cancer. OA may be used as an antitumor drug and deserves further study.

Peritoneal Modulators of Endometriosis-Associated Ovarian Cancer

Ovarian cancer is the 4th largest cause of cancer death in women. Approximately 10–15% of women of childbearing age suffer from endometriosis. Endometriosis is defined by the growth and presence of endometrial tissue (lesions) outside of the uterus. The women with endometriosis also have an increased presence of peritoneal fluid (PF) that comprises of inflammatory cells, growth factors, cytokines/chemokines, etc. Epidemiological studies have shown that >3% of women with endometriosis develop ovarian cancer (low-grade serous or endometrioid types). Our hypothesis is that the PF from women with endometriosis induces transformative changes in the ovarian cells, leading to ovarian cancer development. PF from women with and without endometriosis was collected after IRB approval and patient consent. IOSE (human normal ovarian epithelial cells) and TOV-21G cells (human ovarian clear cell carcinoma cell line) were treated with various volumes of PF (no endometriosis or endometriosis) for 48 or 96 h and proliferation measured. Expression levels of epigenetic regulators and FoxP3, an inflammatory tumor suppressor, were determined. A Human Cancer Inflammation and Immunity Crosstalk RT2 Profiler PCR array was used to measure changes in cancer related genes in treated cells. Results showed increased growth of TOV-21G cells treated with PF from women with endometriosis versus without endometriosis and compared to IOSE cells. Endo PF treatment induced EZH2, H3K27me3, and FoxP3. The RT2 PCR array of TOV-21G cells treated with endo PF showed upregulation of various inflammatory genes (TLRs, Myd88, etc.). These studies indicate that PF from women with endometriosis can both proliferate and transform ovarian cells and hence this microenvironment plays a major mechanistic role in the progression of endometriosis to ovarian cancer.

Long non-coding RNA NRSN2-AS1 facilitates tumorigenesis and progression of ovarian cancer via miR-744-5p/PRKX axis

Newly discovered lncRNA neurensin-2 antisense RNA 1 (NRSN2-AS1) has not been well explored in cancers. Ovarian cancer (OV) is a primary gynecologic cancer worldwide and has the highest mortality rate among gynecologic cancers. Hence, the role and underlying mechanisms of NRSN2-AS1 in OV were worth investigating. According to the results of qRT-PCR, NRSN2-AS1 displayed the remarkably high expression in OV cells, in contrast to human ovarian epithelial cells. Based on online database, the expression level of NRSN2-AS1 was significantly higher in OV tissues than that in normal ovarian tissues. The data from functional experiments indicated that NRSN2-AS1 knockdown inhibited OV cell malignant behaviors in vitro and OV tumor growth in vivo. Moreover, mechanism analysis unveiled that NRSN2-AS1 functioned as a miR-744-5p sponge to regulate PRKX expression in OV cells. The results of TOP/FOP flash and western blot assays suggested that NRSN2-AS1/miR-744-5p/PRKX axis modulated the activity of Wnt/β-catenin signaling pathway. In summary, we validated NRSN2-AS1 functioned as a novel oncogenic lncRNA in OV and elucidated its specific molecular mechanism. This work might advance our understanding of OV and provide evidence for supporting NRSN2-AS1 as a potential biomarker for OV treatment.

Cell type-specific genotoxicity in estrogen-exposed ovarian and fallopian epithelium

Background Loss of the genomic stability jeopardize genome stability and promote malignancies. A fraction of ovarian cancer (OvCa) arises from pathological mutations of DNA repair genes that result in highly mutagenic genomes. However, it remains elusive why the ovarian epithelial cells are particularly susceptible to the malfunction of genome surveillance system. Methods To explore the genotoxic responses in the unique context of microenvironment for ovarian epithelium that is periodically exposed to high-level steroid hormones, we examined estrogen-induced DNA damage by immunofluorescence in OvCa cell lines, animal and human samples. Results We found that OvCa cells are burdened with high levels of endogenous DNA damage that is not correlated with genomic replication. The elevation of damage burden is attributable to the excessive concentration of bioactive estrogen instead of its chemomimetic derivative (tamoxifen). Induction of DNA lesions by estrogen is dependent on the expression of hormone receptors, and occurs in G1 and non-G1 phases of cell cycle. Moreover, depletion of homologous recombination (HR) genes (BRCA1 and BRCA2) exacerbated the genotoxicity of estrogen, highlighting the role of HR to counteract hormone-induced genome instability. Finally, the estrogen-induced DNA damage was reproduced in the epithelial compartments of both ovarian and fallopian tubes. Conclusions Taken together, our study disclose that estrogen-induced genotoxicity and HR deficiency perturb the genome stability of ovarian and fallopian epithelial cells, representing microenvironmental and genetic risk factors, respectively.

The genes CNV features in the tumor cells in patients with ovarian serous adenocarcinoma.

e13641 Background: Serous adenocarcinoma is the most common subtype of ovarian cancer. Early diagnosis of this disease can significantly improve the prognosis. Development of more effective methods for early diagnosis and identification of more reliable markers require understanding the molecular mechanisms underlying the malignant behavior of ovarian epithelial cells. The aim of the study was to analyze the copy number variation (CNV) of genes that regulate apoptosis, DNA repair, cell proliferation, metabolism and estrogen reception in tumor and normal ovarian cells. Methods: For the study, we used tissue sections from FFPE blocks of 65 patients with serous ovarian adenocarcinoma diagnosis. Tumor and normal ovarian epithelial cells were isolated using laser microdissection with non-contact capture (Palm MicroBeam, Carl Zeiss). DNA was extracted from cells using the phenol-chloroform method. CNV of 33 genes (BRAF, KRAS, EGFR, PIK3CA, PTEN, TP53, BRCA1, BRCA2, PRKCI, NOTCH1, AKT1, BAX, CASP7, CASP3, CASP8, CASP9, MDM2, BCL2, CYP1A1, CYP1A1, CYP1A2, CYP1A2, CYP1A2, CYP1A1, CYP1A2, CYP1, ESR2, GPER, STS, SULT1A, SULT1E1, OCT4, SOX2, C-MYC, SOX18, SCNN1A) were determined by Real-Time qPCR method (reference B2M, GAPDH). Statistical analysis was performed using the Mann-Whitney test. For cluster analysis (Hierarchical Clustering, Euclidean distance) scripts in R were used. Results: A statistically significant (p < 0.005) increase in the CNV of PTEN, MDM2, SOX2, CYP1B1, ESR1, and SULT1E1 by 2.0, 2.0, 1.8, 2.5, 3.0 and 2.0 times, respectively, was found, as well as a 2.0-fold decrease in the CNV of CASP3 and CASP8 in tumor cells relatively to normal ones. Cluster analysis allowed us to distinguish 2 groups of serous adenocarcinoma samples that differed in gene CNV (p < 0.005): in group 1 (n = 40), the copy number of the SOX2, MDM2, ESR1, CYP1B1 and SULT1E1 genes was increased and the copy number of the TP53 and BRCA2 genes was reduced, in group 2 (n = 25), copy number of PTEN, PIK3CA, BCL2 was increased and copy number of BAX, CASP3 and CASP8 was lower. Conclusions: CNV analysis revealed the most characteristic markers of ovarian serous adenocarcinoma cells. Based on the differential CNV, 2 molecular subtypes of serous adenocarcinoma were distinguished.