Effects of HOXA1 Gene Antisense Oligonucleotides on Growth of Esophageal Cancer Cells

  Objective  To investigate the effect of antisense oligodeoxynucleotides (ASODN) of Homeobox A1 gene (HOXA1) on proliferation, apoptosis, invasion and migration of esophageal carcinoma cells.

  Methods  The expression of HOXA1 protein in normal esophageal epithelial cells Het-1A and esophageal cancer TE-1, EC9706 and Eca109 cells was detected by Western blot. Screening of highly expressed of HOXA1 protein esophageal squamous cell carcinoma cells for follow-up experiments. HOXA1 antisense oligonucleotide (ASODN) chains, sense oligodeoxynucleotides (SODN) chain, and nonsense oligodeoxy nucleotides (N-ODN) chain were designed. The screened esophageal squamous cell carcinoma cells with high expression were divided into HOXA1 ASODN group (5, 10, 15 μmol/L HOXA1 ASODN transfected Eca109 cells), control group (conventional culture medium, no cell transfection), SODN group (cells transfected with 15 μmol/L of SODN) and N-ODN group (cells transfected with 15 μmol/L N-ODN). Cell viability, apoptosis rate and invasion and migration ability were detected by methylthiazolyldiphenyl-tetrazolium bromide (MTT) method, flow cytometry, transwell chamber respectively; The expression of HOXA1, phosphorylation serine/threonine kinase (p-AKT), proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 2 (MMP-2) and B-cell lymphoma2 (Bcl-2) associated X protein (Bax) protein was detected by Western blot.

  Results  Compared with normal esophageal epithelial cells Het-1A, the expression of HOXA1 protein in human esophageal squamous cell carcinoma cells TE-1, EC9706 and Eca109 was significantly higher (P<0.05). The expression of HOXA1 protein was the highest in Eca109 cells, therefore, Eca109 cells were selected for follow-up experiments. The expression of HOXA1 protein in Eca109 cells transfected with HOXA1 ASODN was significantly decreased (P<0.05). After transfection of Eca109 cells with HOXA1 ASODN, the viability of Eca109 cells decreased with the increase of concentration and time, the difference was significant compared with the control, SODN and N-ODN groups (P<0.05). 15 μmol/L HOXA1 ASODN significantly inhibited cell viability. After 15 μmol/L HOXA1 ASODN was transfected into Eca109 cells, the invasion and migration abilities of cells were significantly decreased, the apoptosis rate was increased, the expressions of p-AKT, PCNA and MMP-2 were significantly decreased, and the expression of Bax was significantly increased (P<0.05).

  Conclusion  Antisense oligodeoxynucleotides of HOXA1 gene can inhibit the proliferation, invasion and migration of esophageal cancer cells, and induce apoptosis. The mechanism is related to the inhibition of PI3K/AKT signaling pathway.