Effects of NVP-BEZ235 on the proliferation, migration, apoptosis and autophagy in HT-29 human colorectal adenocarcinoma cells.

The phosphoinositide 3 kinase (PI3K)/Akt/mammalian target of the rapamycin (mTOR) pathway plays a significant role in colorectal adenocarcinoma. NVP-BEZ235 (dactolisib) is a novel dual inhibitor of PI3K/mTOR. The effects of NVP-BEZ235 in human colorectal adenocarcinoma are still unclear. In the present study, we aimed to explore the proliferation, migration, apoptosis and autophagy in HT-29 human colorectal adenocarcinoma cells. HT-29 human colorectal adenocarcinoma cells were treated with NVP-BEZ235 (0, 0.001, 0.01, 0.1, 1 and 3 µM) for 24 and 48 h, respectively. Cells were also treated with NVP-BEZ235 (0.1 µM), DDP (100, 300 and 1,000 µM), and NVP-BEZ235 (0.1 µM) combined with DDP (100, 300 and 1,000 µM) respectively, and cultured for 24 h after treatment. MTT assay was utilized to evaluate the effects of NVP-BEZ235 alone or NVP-BEZ235 combined with cis-diamminedichloroplatinum (DDP) on proliferation of HT-29 cells. Cell wound-scratch assay was used detect cell migration. In addition, expression of microtubule-associated proteins 1A/1B light chain 3B (MAP1LC3B and LC3B) in HT-29 cells was detected by immunofluorescence at 48 h after NVP-BEZ235 (1 µM) treatment. Expression of proteins involved in cell cycle and proliferation (p-Akt, p-mTOR and cyclin D1), apoptosis (cleaved caspase-3), and autophagy (cleaved LC3B and Beclin-1) were detected by western blot analysis. NVP-BEZ235 inhibited the proliferation and migration of HT-29 human colorectal adenocarcinoma cells. NVP-BEZ235 decreased protein expression of p-Akt, p-mTOR and cyclin D1, and increased protein expression of cleaved caspase-3, cleaved LC3B and Beclin-1 as the concentrations and the incubation time of NVP-BEZ235 increased. In addition, NVP-BEZ235 and DDP had synergic effects in inhibiting cell proliferation and migration. The expression of protein involved in apoptosis (cleaved caspase-3) was higher in drug combination group compared to the NVP-BEZ235 single treatment group. NVP-BEZ235 inhibited the proliferation and migration, and induced apoptosis and autophagy of HT-29 human colorectal adenocarcinoma cells.