Effects of moderate hypoxia on invasion and metastasis of colon carcinoma cell line HT-29 in vitro / 第三军医大学学报

ABSTRACT

Objective To investigate the correlation between moderate hypoxia and maliglant transformation of colon carcinoma cell line HT-29.Methods Hypoxic conditions were produced according to p(O2)of tumor in vivo.The heterotypic adhesiveness of HT-29 cells was detected by MTT assay.Their reaction to the hypoxic environment was determined via invasion across a Matrigel-coated Transwell filter.At 0,6,12,24 and 48 h after hypoxia,MMP-2/9 activities were assessed by gelatin zymography,and osteopontin mRNA and protein levels by RT-PCR and Western blot respectively.NF-?B/p65 levels in nucleus was measured by Western blot after extraction of nucleic protein.Results After 24-hour moderate hypoxia,the heterotypic adhesiveness and invasive capacity of HT-29 cells were significantly enchanced.MMP-2,MMP-9 activities under moderate hypoxia for 6 h showed no significant change as compared with that under normoxia,then gradually up-regulated and reached the peak at 24 h.They showed no significant difference between 24 h and 48 h after hypoxia.The expression trend of osteopontin mRNA,protein and NF-?B/p65 protein in nucleus was similar to that of MMP-2,MMP-9 under moderate hypoxia.Conclusion Moderate hypoxia could induce maliglant transformation in HT-29 cells through enhancing heterotypic adhesiveness and invasive capacity and upregulating MMP-2,MMP-9 activities.OPN-NF-?B may be an important regulatory pathway besides HIF-1 under hypoxic condition,which involves maliglant phenotype induced by moderate hypoxia.