ABSTRACT
This study was aimed to explore the influence of breast cancer associated fibroblasts (CAFs) in migration and invasion of breast cancer cell line MCF-7,and investigate whether hepatocyte growth factor (HGF) is involved in this process.Primary breast CAFs and their corresponding normal breast fibroblasts (NFs) were obtained by collagenase digestion.On the basis of the co-culture,the migration and invasion capacity of MCF-7 cells was compared between CAFs and NFs by Transwell.The difference in the HGF expression between them was detected by ELISA.The secretion of HGF was knocked down by using RNA interference technology in CAFs.Then the changes of migration and invasion capacity of MCF-7 cells were investigated by Transwell.Eventually,we isolated high-purity CAFs and NFs,and the CAFs had a stronger ability in promoting MCF-7 migration and invasion than the NFs.ELISA results demonstrated that CAFs secreted higher HGF,and the capacity of MCF-7 migration and invasion was declined after knocking down the secretion of HGF in CAFs by RNA interference.It is suggested that CAFs can promote MCF-7 migration and invasion through HGF in vitro.
ABSTRACT
Chemotherapy is the preferred therapeutic approach for advanced ovarian cancer,but a suceessful long-term treatment is prevented by the development of drug resistance.Recent works have underlined the involvement of non-coding RNAs,microRNAs (miRNAs) in cancer development,with several conjectures regarding their possible involvement in the evolution of drug resistance.This study is to investigate the promoting effects and mechanism of miR-125b involved in the development of chemoresistance in ovarian cancer.The different expression of miR-125b in cisplatin-sensitive ovarian cancer cell line (OV2008) and its resistant variant (C13*) was identified by real-time PCR.An in vitro cytotoxicity assay and apoptosis assay using CCK-8 assay and flow cytometry,were carried out to detect the effect of miR-125b and Bak1 on cisplatin resistance of cells.Real-time PCR,Western blotting and luciferase reporter assay were used to detect whether Bak1 is a target of miR-125b.As compared with OV2008 cells,the expression levels of miR-125b in C13* cells were increased.It was found that the up-regulation of microRNA-125b caused a marked inhibition of cisplatin-induced cytotoxicity and apoptosis and a subsequent increase in the resistance to cisplatin in OV2008 and C13* cells.Moreover,Bakl was a direct target of miR-125b,and down-regulation of Bak1 suppressed cisplatin-induced apoptosis and led to an increased resistance to cisplatin.Our study indicates that miR-125b has a significantly promoting effect on chemoresistance of C13* cells and up-regulation of miR-125b expression contributes to cisplatin resistance through suppression of Bakl expression.This finding has important implications in the development of targeted therapeutics for overcoming cisplatin resistance in ovarian cancer.
ABSTRACT
Recent evidence has suggested that Akt2 plays an important role in the protection of cells from paclitaxel(PTX)-induced apoptosis and control of the cell cycle.In addition,some scholars suggested that the PTX sensitivity depends on a functional spindle assembly checkpoint.In the present study,we investigated the role of the Akt2/Bub1 cross-talking in apoptosis and cell cycle after exposure of the A2780 ovarian cancer cells to paclitaxel(PTX).Recombinant expression plasmid WT-Akt2 was transfected into A2780 cells by lipofectamine2000,and then the expression level of Akt2 gene was detected by using RT-PCR and Western blotting.Cell apoptosis and cell cycle were detected by flow cytometry and Hoechst 33342 staining after treatment with PTX.Moreover,we compared the expression level of Bubl in different groups by Western blotting.Our study showed that up-regulation of Akt2 contributed to A2780 ovarian cancer cells overriding PTX-induced G2/M arrest,and inhibited Bub1 expression.Our findings might shed light on the molecular mechanism of PTX-induced resistance in ovarian cancer and help develop novel anti-neoplastic strategies.