Bcl2l10 induces metabolic alterations in ovarian cancer cells by regulating the TCA cycle enzymes SDHD and IDH1.

Bcl2­like­10 (Bcl2l10) has both oncogenic and tumor suppressor functions depending on the type of cancer. It has been previously demonstrated that the suppression of Bcl2l10 in ovarian cancer SKOV3 and A2780 cells causes cell cycle arrest and enhances cell proliferation, indicating that Bcl2l10 is a tumor suppressor gene in ovarian cancer cells. The aim of the present study was to identify possible downstream target genes and investigate the underlying mechanisms of action of Bcl2l10 in ovarian cancer cells. RNA sequencing (RNA­Seq) was performed to obtain a list of differentially expressed genes (DEGs) in Bcl2l10­suppressed SKOV3 and A2780 cells. The RNA­Seq data were validated by reverse transcription­quantitative PCR (RT­qPCR) and western blot analysis, and the levels of metabolites after Bcl2l10­knockdown were measured using colorimetric assay kits. Pathway enrichment analysis revealed that the commonly downregulated genes in SKOV3 and A2780 cells after Bcl2l10­knockdown were significantly enriched in metabolic pathways. The analysis of the DEGs identified from RNA­Seq and validated by RT­qPCR revealed that succinate dehydrogenase complex subunit D (SDHD) and isocitrate dehydrogenase 1 (IDH1), which are key enzymes of the TCA cycle that regulate oncometabolite production, may be potential downstream targets of Bcl2l10. Furthermore, Bcl2l10­knockdown induced the accumulation of succinate and isocitrate through the downregulation of SDHD and IDH1. The present study was the first to elucidate the metabolic regulatory functions of Bcl2l10 in ovarian cancer cells, and the results indicated that Bcl2l10 may serve as a potential therapeutic target in ovarian cancer.

miR-4463 regulates aromatase expression and activity for 17ß-estradiol synthesis in response to follicle-stimulating hormone.

OBJECTIVE: The aim of this study was to investigate microRNAs (miRNAs) related to follicle-stimulating hormone (FSH) responsiveness using miRNA microarrays and to identify their target genes to determine the molecular regulatory pathways involved in FSH signaling in KGN cells. METHODS: To change the cellular responsiveness to FSH, KGN cells were treated with FSH receptor (FSHR)-specific small interfering RNA (siRNA) followed by FSH. miRNA expression profiles were determined through miRNA microarray analysis. Potential target genes of selected miRNAs were predicted using bioinformatics tools, and their regulatory function was confirmed in KGN cells. RESULTS: We found that six miRNAs (miR-1261, miR-130a-3p, miR-329-3p, miR-185-5p, miR-144-5p and miR-4463) were differentially expressed after FSHR siRNA treatment in KGN cells. Through a bioinformatics analysis, we showed that these miRNAs were predicted to regulate a large number of genes, which we narrowed down to cytochrome P450 family 19 subfamily A member 1 (CYP19A1) and estrogen receptor alpha (ESR1) as the main targets for miR-4463. Functional analysis revealed that miR-4463 is a regulatory factor for aromatase expression and function in KGN cells. CONCLUSION: In this study, we identified differentially expressed miRNAs related to FSH responsiveness. In particular, upregulation of miR-4463 expression by FSHR deficiency in human granulosa cells impaired 17ß-estradiol synthesis by targeting CYP19A1 and ESR1. Therefore, our data might provide novel candidates for molecular biomarkers for use in research into poor responders.

Bcl2l10 mediates the proliferation, invasion and migration of ovarian cancer cells.

Bcl2l10, also known as Diva, Bcl­b and Boo, is a member of the Bcl2 family of proteins, which are involved in signaling pathways that regulate cell apoptosis and autophagy. Previously, it was demonstrated that Bcl2l10 plays a crucial role in the completion of oocyte meiosis and is a key regulator of Aurora kinase A (Aurka) expression and activity in oocytes. Aurka is overexpressed in several types of solid tumors and has been considered a target of cancer therapy. Based on these previous results, in the present study, the authors aimed to investigate the regulatory role of Bcl2l10 in A2780 and SKOV3 human ovarian cancer cells. The protein expression of Bcl2l10 was examined in human cancer tissues and cell lines, including the ovaries, using a tissue microarray and various human ovarian cancer cell lines. It was found that Bcl2l10 regulated the protein stability and activities of Aurka in ovarian cancer cells. Although apoptosis was not affected, the cell cycle was arrested at the G0/G1 phase by Bcl2l10 knockdown. Of note, cell viability and motility were markedly increased by Bcl2l10 knockdown. On the whole, the findings of this study suggest that Bcl2l10 functions as tumor suppressor gene in ovarian cancer.

Contribution of the PI3K/Akt/PKB signal pathway to maintenance of self-renewal in human embryonic stem cells.

Although basic fibroblast growth factor (FGF2) is generally included in the media for maintenance of human embryonic stem cells (hESCs), the action of FGF2 in these cells has not been well defined. Here, we determined the roles of FGF2 in maintaining hESC self-renewal. Withdrawal of FGF2 from the media led to acquisition of typical differentiated characteristics in hESCs. In the presence of FGF2, which is normally required for proliferation in an undifferentiated state, inhibition of phosphatidylinositol 3-kinase (PI3K)/Akt/PKB signal stimulated differentiation and attenuated the expression of extracellular matrix (ECM) molecules. We suggest that FGF2 maintains hESC self-renewal by supporting stable expression of ECM molecules through activation of the PI3K/Akt/PKB pathway.