ABSTRACT
We investigated the inhibitory effect and mechanism of action of bruceantin (BCT) on the proliferation, invasion and migration of non-small cell lung cancer (NSCLC) cells. The cytotoxic activity of BCT was measured by MTT assay; a colony forming assay, wound healing assay, and a Transwell assay were used to investigate the anti-proliferative, anti-migration, and anti-invasion effects, respectively; immunoblotting and RT-qPCR were used to detect the expression of related proteins, miRNA, and mRNA, respectively, that were involved in cell proliferation, migration, and invasion. Two gene prediction websites were used to predict the downstream target gene of miRNA. Our results show that BCT has a potent cytotoxic effect on NSCLC cell lines, with a half maximal inhibitory concentration (IC50) of BCT against H1299, PC-9, and A549 of 0.12 ± 0.02, 0.31 ± 0.20, and 2.07 ± 0.70 μmol·L-1, respectively. When H1299 cells were treated with 0.03, 0.15, and 0.75 μmol·L-1 BCT for 24 h, the proliferation, migration, and invasive ability were inhibited in a concentration-dependent manner. It is worth noting that the expression level of miRNAs related to cell migration and invasion, such as miR-29a-3p, miR-21-3p, miR-183-5p, and miR-34b-5p increased with the concentration of BCT, especially for miR-29a-3p. Using the two gene prediction websites, we predict that integrin β1 (ITGB1) may be the target gene of miR-29a-3p; immunoblot results further show that a variety of proteins related to cell proliferation, migration, and invasion, such as various proteins of the integrin family, β-catenin, p-Src, and vascular endothelial growth factor, all decreased in a concentration-dependent manner, among which the reduction of ITGB1 protein was the most obvious. RT-qPCR results showed that there was no change in ITGB1 mRNA expression. We speculate that BCT might inhibit the expression of ITGB1 protein by up-regulating miR-29a-3p independent of its mRNA level. The in-depth mechanism needs to be further explored. This study suggests that BCT has the potential for further development in the treatment of NSCLC.
ABSTRACT
Sevoflurane (SEVO) is widely applied as an anesthetic, which exerts antitumor capacity in various cancers, including hepatocellular carcinoma (HCC). Previous studies indicated that long non-coding RNA KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) was upregulated, while microRNA-29a-3p (miR-29a-3p) was downregulated in HCC. Thus, we aimed to explore the roles of KCNQ1OT1 and miR-29a-3p in HCC cells exposed to SEVO. Cell proliferation, apoptosis, migration, and invasion were assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, flow cytometry, and transwell assays, respectively. The levels of genes were determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Furthermore, the interaction between miR-29a-3p and KCNQ1OT1 or chromebox protein homolog 3 (CBX3) was predicted by Starbase or Targetscan, and then confirmed by dual-luciferase reporter assay. We found that the levels of KCNQ1OT1 and CBX3 were decreased, while miR-29a-3p was increased in SEVO-treated HCC cells. KCNQ1OT1 overexpression weakened the inhibitory effects of SEVO on HCC cell proliferation, apoptosis, migration, and invasion. Interestingly, KCNQ1OT1 bound to miR-29a-3p, and miR-29a-3p targeted CBX3. KCNQ1OT1 upregulated CBX3 level by repressing miR-29a-3p expression. Furthermore, KCNQ1OT1 exerted tumor promotion in HCC cells via suppressing miR-29a-3p to regulate CBX3 expression. Collectively, our findings demonstrated that KCNQ1OT1 regulated the antitumor effects of SEVO on HCC cells through modulating the miR-29a-3p/CBX3 axis, providing a theoretical basis for the treatment of HCC.