Exploration of target genes of HOXA13 in esophageal squamous cell carcinoma cell line.

Homeobox genes encode transcriptional factors which regulate cell proliferation and differentiation and have been found to be deregulated in many tumors. Previously, we found that the median survival time of patients with ESCC (Esophageal squamous cell carcinoma) expressing HOXA13 was significantly shorter than those with HOXA13-negative ESCC and we also demonstrated that knockdown of HOXA13 blocked cell proliferation in vitro and in vivo. In this study, we examined the protein expression changes after HOXA13 knockdown by 2-dimentional electrophoresis. Forty-five spots were significantly different, among which 24 were down-regulated and 21 were up-regulated after HOXA13 knockdown. The proteins from 14 gel-spots were further characterized by MALDI-TOF MS, among which, AnnexinA2, MnSOD and ERAB, are validated by Western Blot analysis. Transcriptional target analysis revealed that HOXA13 regulated several cell signaling pathways that are critically involved in cell proliferation, survival and migration. These results provide an additional support to a hypothesis that HOXA13 might participate in the carcinogenesis of ESCC.