CircATL2 enhances paclitaxel resistance of ovarian cancer via impacting miR-506-3p/NFIB axis.

Circular RNAs (circRNAs) play vital regulatory roles in the development of ovarian cancer (OC). However, the functions of circRNA Atlastin GTPase 2 (circATL2) in paclitaxel (PTX) resistance of OC are still unclear. As a result, circATL2 was upregulated in PTX-resistant OC tissues and cells. CircATL2 knockdown reduced IC50 of PTX, inhibited colony formation ability and promoted cell cycle arrest and apoptosis in PTX-resistant OC cells. Silencing of circATL2 restrained PTX resistance in vivo. Furthermore, miR-506-3p could be targeted by circATL2 and miR-506-3p inhibition reversed the impacts of circATL2 knockdown on PTX resistance and cell progression in PTX-resistant OC cells. NFIB was identified as the target of miR-506-3p. MiR-506-3p overexpression suppressed PTX resistance and malignant behaviors of PTX-resistant OC cells, with NFIB elevation rescued the impacts. To summarize, circATL2 promoted the resistance of OC to PTX by sponging miR-506-3p to upregulate NFIB expression, providing a new sight in chemoresistance of OC.

Capilliposide from Lysimachia capillipes promotes terminal differentiations and reverses paclitaxel resistance in A2780T cells of human ovarian cancer by regulating Fos/Jun pathway.

Objective: To investigate the potential effect of Lysimachia capillipes capilliposide (LCC) on the chemo sensitivity and the stemness of human ovarian cancer cells. Methods: Cell Counting Kit-8 (CCK8) was used to measure the IC50 values. The apoptosis of cells was measured through flow cytometry. Evaluation of the stemness and differentiation markers was performed by the immunoblotting and the immunostaining assays. RNA-seq was performed through the Illumina HiSeq PE150 platform and differentially expressed genes (DEGs) were screened out through the bioinformation analysis. Overexpression or knockdown of Fos gene was achieved by shRNA transfection. Results: Pre-exposure of A2780T cells with 10 µg/mL LCC sensitized them to paclitaxel, of which the IC50 value reduced from 8.644 µmol/L (95%CI: 7.315-10.082 µmol/L) to 2.5 µmol/L (95%CI: 2.233-2.7882 µmol/L). Exposure with LCC enhanced the paclitaxel-induced apoptosis and inhibited the colony formation of A2780T cells. LCC exposure reduced the expression of cancer stemness markers, ALDH1, Myd88 and CD44, while promoting that of terminal differentiation markers, NFATc1, Cathepsin K and MMP9. RNA-seq analysis revealed that the expressions of FOS and JUN were upregulated in LCC-treated A2780T cells. A2780T cells overexpressing Fos gene displayed increased paclitaxel-sensitivity and reduced cell stemness, and shared common phenotypes with LCC-treated A2780T cells. Conclusion: These findings suggested that LCC promoted terminal differentiations of ovarian cancer cells and sensitized them to paclitaxel through activating the Fos/Jun pathway. LCC might become a novel therapy that targets at cancer stem cells and enhances the chemotherapeutic effect of ovarian cancer treatments.