Identification of downstream target genes regulated by CX43 in hepatocellular carcinoma

Zu-Sen Wang, Zhen Tan, Ze-Hua Wu, Shi-Xiong Zhan, Wei-Dong Guo, Shi-Guo Liu,  Lu Zhang

Abstract:

The aim of study was to identify the downstream target genes of CX43 by Human Transcriptome Array. Therefore, a gene microarray was generated consisting of CX43-overexpressed hepatocellular carcinoma (HCC) cells, transfected with the constructed plasmid and negative controls, to identify candidate genes. Integrated bioinformatic analysis was used to clarify biological functions of the identified genes, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, protein-protein interaction network and survival analysis. The candidate genes were further validated by qRT-PCR in liver cancer tissues and CX43-silenced HCC cells. We have found the mRNA and protein levels of CX43 significantly upregulated in HCC cells transfected with CX43 constructed plasmid. We identified 928 differentially expressed genes including 394 upregulated and 534 downregulated genes, enriched in the cancer related functions and pathways by GO and KEGG pathway analysis. The protein-protein interaction network revealed 9 hub genes in this study. Statistical analysis indicated that upregulation of RALA and SRC was associated with poor prognosis in liver cancer. The differential expressions of 2 candidate genes were further validated in HCC cells and tissues. In conclusion, protein-coding genes RALA and SRC could be target genes of CX43 and therapeutic targets for hepatocellular carcinoma.