Open AccessTBRG4 silencing promotes progression of squamous cell carcinoma via regulation of CAV-1 expression and ROS formation
Author(s) -
Junqi Wang,
Qin Luo,
Mingwei Liu,
Chao Zhang,
Yong Rui Jia,
Ruifeng Tong,
Litao Yang,
Xiaowei Fu
Publication year - 2020
Publication title -
cellular and molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 71
eISSN - 1165-158X
pISSN - 0145-5680
DOI - 10.14715/cmb/2020.66.2.26
Subject(s) - gene knockdown , cell cycle , apoptosis , reactive oxygen species , cell growth , gene silencing , cell cycle checkpoint , small interfering rna , chemistry , g1 phase , downregulation and upregulation , cancer research , cell , cell culture , microbiology and biotechnology , biology , transfection , biochemistry , genetics , gene
Esophageal cancer is the eighth most common cancer globally. Transforming growth factor β regulator 4 (TBRG4) and caveolin-1 (CAV-1) are implicated in tumor progression. The aim of this study was to investigate the expressions of TBRG4 and CAV-1 in esophageal squamous cell carcinoma (ESCC), and their relationship with reactive oxygen species (ROS) formation. Human ESCC cell lines (EC9706, TE-1, and Eca109), and normal esophageal mucosal cell line (Het-1) were used in this study. The silencing of TBRG4 and/or CAV-1 by sh-RNA or overexpression of CAV-1 after TBRG4 knockdown was used to assess ROS levels. The results showed that down-regulation of TBRG4 reduced CAV-1 expression, and promoted ROS formation in ESCCs (p < 0.01). However, CAV-1 overexpression increased the expression level of TBRG4, but decreased ROS level in EC9706 cells (p < 0.01). Similarly, TBRG4 knockdown significantly reduced CAV-1 expression, promoted ROS formation, and caused cell cycle arrest at G0/G1 phase (p < 0.01). Caveolin-1 (CAV-1) knockdown also promoted cell apoptosis, cellular ROS formation and cell cycle arrest at G0/G1 phase (p < 0.01). However, CAV-1 overexpression in sh-TBRG4-treated EC9706 cells significantly upregulated TBRG4 expression, but significantly reduced the level of ROS, and inhibited cell-cycle arrest and apoptosis (p < 0.01). The enhancements in bcl-2/bax ratio, cytochrome c expression, and ROS levels by sh-TBRG4 were significantly reversed by CAV-1 overexpression in EC9706 cells. These results show that the upregulated expression of TBRG4 or CAV-1 promotes ESCC progression via regulation of intracellular ROS levels and inhibition of mitochondria-dependent apoptotic pathway.