Zhigang Xiao1, Zhan Qu2, Zhikang Chen3, Zhixue Fang1, Ke Zhou1, Zhongcheng Huang1, Xiong Guo3, Yang Zhang3. 1. Department of general surgery, Hunan Provincial People's Hospital, the First Affiliated Hospital of Hunan Normal University, Changsha, China. 2. General Surgery Department, Xiangya Hospital, Central South University, Changsha, China. 3. Colorectal anal surgical department, Hepatobiliary and Enteric Surgery Center, Xiangya Hospital, Central South University, Changsha, China.
Abstract
BACKGROUND/AIMS: HOX transcript antisense RNA (HOTAIR) plays a vital role in carcinogenesis. However, its functional and regulatory roles remain unclear. In this study, we aimed to investigate its biological function and clinical significance in human colorectal cancer (CRC). METHODS: We examined the expression levels of lncRNA HOTAIR and miR-203a-3p in CRC tissues and CRC cell lines by qRT-PCR. Gain and loss-of-function assays were performed to examine the effects of HOTAIR and miR-203a-3p on the proliferation and chemoresistance of CRC cells. The possible mechanisms of HOTAIR were also explored by fluorescence reporter assay and Western blot. RESULTS: The expressions of HOTAIR were upregulated in CRC tissue tissues compared to adjacent control tissues. We also found HOTAIR was downregulated by miR-203a-3p in CRC cell lines. Both HOTAIR knockdown and miR-203a-3p overexpression in CRC cell lines led to inhibited cell proliferation and reduced chemoresistance. We also determined that β-catenin and GRG5 were inhibitory targets of miR-203a-3p, and that Wnt/β-catenin signaling was inhibited by both HOTAIR knockdown and miR-203a-3p overexpression. Significantly, we found that increased expression of miR-203a-3p is essential for cell proliferation repression, chemoresistance reduction, and Wnt/β-catenin signaling inhibition induced by HOTAIR knockdown. CONCLUSIONS: Our study demonstrated that the lncRNA HOTAIR could regulate the progression and chemoresistance of CRC via modulating the expression levels of miR-203a-3p and the activity of Wnt/β-catenin signaling pathway.
BACKGROUND/AIMS: HOX transcript antisense RNA (HOTAIR) plays a vital role in carcinogenesis. However, its functional and regulatory roles remain unclear. In this study, we aimed to investigate its biological function and clinical significance in humancolorectal cancer (CRC). METHODS: We examined the expression levels of lncRNA HOTAIR and miR-203a-3p in CRC tissues and CRC cell lines by qRT-PCR. Gain and loss-of-function assays were performed to examine the effects of HOTAIR and miR-203a-3p on the proliferation and chemoresistance of CRC cells. The possible mechanisms of HOTAIR were also explored by fluorescence reporter assay and Western blot. RESULTS: The expressions of HOTAIR were upregulated in CRC tissue tissues compared to adjacent control tissues. We also found HOTAIR was downregulated by miR-203a-3p in CRC cell lines. Both HOTAIR knockdown and miR-203a-3p overexpression in CRC cell lines led to inhibited cell proliferation and reduced chemoresistance. We also determined that β-catenin and GRG5 were inhibitory targets of miR-203a-3p, and that Wnt/β-catenin signaling was inhibited by both HOTAIR knockdown and miR-203a-3p overexpression. Significantly, we found that increased expression of miR-203a-3p is essential for cell proliferation repression, chemoresistance reduction, and Wnt/β-catenin signaling inhibition induced by HOTAIR knockdown. CONCLUSIONS: Our study demonstrated that the lncRNA HOTAIR could regulate the progression and chemoresistance of CRC via modulating the expression levels of miR-203a-3p and the activity of Wnt/β-catenin signaling pathway.