TUBB3 promotes growth and invasion of gallbladder cancer cell by Akt/mTOR signal pathway

Aberrant expression of β-tubulin-III (TUBB3) is known that related to aggressive tumor features and poor clinical outcomes. However, there is limited research about TUBB3 expression and its role in the outcomes and the progression of gallbladder cancer. We have measured TUBB3 level in gallbladder cancer samples and cell lines from 2012 to 2016, and tested the effects of TUBB3 in cancer cell growth, apoptosis and cell cycle arrest by using appropriate methods. The results revealed that TUBB3 was significantly over-expressed in gallbladder cancer samples and cell lines, and high TUBB3 level contributed to shorter overall survival in patients. The knockdown of TUBB3 with sh-TUBB3 inhibited the proliferation, migration and invasion of cancer cells. Meanwhile, it promotes apoptosis and changes the cell cycle distribution. Suppression of TUBB3 expression could increase p21 and cyclin B1 expression, and decrease cyclin D1. Xenograft mouse model also showed that low expression of TUBB3 reduced the growth of established gallbladder cancer xenograft in vivo. Furthermore, TUBB3 knockdown significantly decreased phosphorylation of Akt and mTOR in vitro and in vivo. TUBB3 can induce the development of gallbladder cancer by Akt/mTOR signal pathway and we point out a potential therapeutic target for gallbladder cancer treatment.