Abstract
BACKGROUND This study aimed to investigate the effects of metastasis-associated 1 (MTA1) gene expression and gene silencing in human non-small cell lung cancer (NSCLC) cells in vitro and on angiogenesis in tumor xenografts in vivo in nude mice. MATERIAL AND METHODS Human H460 and H1299 NSCLC cell lines underwent transfection with lentiviral transfer plasmids (lenti) and short-interfering RNA (si-RNA) and included a control group, a lenti-MTA1 group, a lenti-si-MTA1 group, a lenti control group, and a si-RNA control group. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect MTA1 gene expression after cell transfection. MTA1 transfection was more effective in H460 cells, which were selected for further in vivo studies. Sixty Balb/c nude mice, containing human H460 cell tumor xenografts, included a control group (N=20), a lenti-MTA1 group (N=20), and a lenti-si-MTA1 group (N=20). Tumor tissue immunohistochemistry was used to detect the expression of MTA1 protein and microvessel density (MVD) using CD31. Western blot was used to quantify the expression of cyclooxygenase-2 (COX-2), angiopoietin 1/2 (Ang1/2), hypoxia-inducible factor 1-a (HIF-1a), and vascular endothelial growth factor (VEGF). RESULTS MTA1 silencing with si-RNA significantly reduced the tumor growth rate in nude mice (p<0.01), reduced tumor MVD, and 70% of mice survived for more than 30 days. MTA1 overexpression resulted in the death of all mice at 30 days after tumor inoculation and upregulated the expression of COX-2, Ang1/2, HIF-1a and VEGF, which were down-regulated by MTA1 silencing. CONCLUSIONS MTA1 gene expression promoted angiogenesis in mouse xenografts from human NSCLC cells.