Purpose: HOXA13  is a transcription factor of the Homeobox (HOX ) gene family, which is highly evolutionarily conserved. HOXA13  is upregulated and associated with oncogenic properties in some cancers. Here, we studied the potential mechanism of HOXA13 -mediated proliferation and metastasis in gastric cancer (GC).
Methods: Quantitative real-time PCR, Western blot, and immunohistochemistry were used to detect HOXA13 expression levels in GC. In vitro and in vivo assays were performed to investigate the function of HOXA13  in GC cell proliferation, migration, and invasion. RNA-Seq transcriptome analysis was performed to study the underlying mechanism of HOXA13 -mediated aggressiveness in GC.
Results: HOXA13 mRNA and protein expression levels were upregulated in GC tissues. According to Cell Counting Kit-8 and colony formation assays, we found that HOXA13  overexpression promoted proliferation. Flow cytometry analysis showed that HOXA13  overexpression or knockdown led to G1-S phase transition or G1 phase arrest, respectively. Western blot analysis results showed that HOXA13 overexpression increased cyclin D1 expression, while knockdown decreased its expression. Wound healing and transwell assay results demonstrated that HOXA13  overexpression promoted the migration and invasion of GC cells. Western blot analysis results also showed that HOXA13 overexpression upregulated N-cadherin and vimentin and downregulated E-cadherin, while HOXA13 knockdown led to the opposite results, indicating that HOXA13 might participate in epithelial to mesenchymal transition. These results were verified in vivo by tumor xenograft and metastasis assays. Mechanistically, using RNA-Seq transcriptome analysis, we found that Erk1/2 activation played an important role in HOXA13 -induced GC progression.
Conclusion: Our results show that HOXA13  plays an important role in GC development. HOXA13  overexpression promotes proliferation and metastasis partly via activation of Erk1/2 in GC. Thus, HOXA13, together with Erk1/2, may be promising targets for novel anticancer strategies.
Keywords: gastric cancer, HOXA13 , Erk1, Erk2, proliferation, metastasis