Hypoxia inducible factor 1α expression in colorectal cancer and its correlation with Survivin

Objective To investigate the correlation between the expression levels of hypoxia inducible factor-1α (HIF-1α) and Survivin in human the colorectal carcinomas (CRCs).Methods Plasmid expressing small interfering RNA (siRNA) targeting HIF-1 α mRNA (pSilence-2.1-U6-siRNA ) was constructed and transfected into LS174T cells by Lipofectamine methods.The effect of HIF-1α on the expression of survivin by siRNA targeting HIF-1α mRNA was studied.The expression of survivin and HIF-1α was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.The expression of HIF-1 α and Survivin was investigated by immunohistochemistry in 69 patients with CRCs.Results The successful construction of pSilence-2.1-U6-siRNA plasmid was confirmed by sequencing analysis.HIF-1 α and Survivin expression levels were markedly down-regulated after the siRNA expression vector targeting HIF-1α was transfected into the LS174T cells.The positive rate of HIF-1α protein in CRCs was significantly higher than that in colorectal adenoma lesions ( P ＜ 0.05 ).There was significant difference in the expression of HIF-1α protein between stage Ⅲ and stage Ⅰ-Ⅱ CRCs (P ＜0.01 ).The level of HIF-1αwas positively correlated with that of Survivin protein ( P ＜ 0.05 ) during colorectal tumor progression.Conclusion There is a positive correlation between the expression levels of HIF-1αt and Survivin in tumor progression of human CRCs. Key words: Hypoxia inducible factor-1 α; Survivin; Small interfering RNA; Colorectal carcinoma