ABSTRACT
Objective:To preliminarily verify the cross talk between tissue factor/active coagulation factor Ⅶ (TF/FⅦa) and epidermal growth factor receptor (EGFR) pathways in human colon cancer cells in culture.Methods:FⅦa was treated to HT-29 (KRAS-wild type) and LoVo (KRAS-mutant) colon cancer cells to activate TF/F Ⅶa pathway,qRT-PCR and Western blot were used to detect the expressions of amphiregulin (AREG) and epiregulin (EREG),ligands of EGFR on mRNA and protein levels,respectively.After knocking down expression of TF by TF-targeted siRNA transfection,FⅦa was treated and mRNA expressions of AREG and EREG were detected to see whether the FⅦa-induced effects were dependent on TF.Expressions of mRNA of TF and FⅦwere detected by qRT-PCR following the activation of EGFR pathway by treatment with epidermal growth factor (EGF) to HT-29 and LoVo cells.Results:After TF/FⅦa pathway was activated,for HT-29 cells,expressions of AREG (on mRNA level) and EREG (both on mRNA and protein level) were significantly down-regulated versus those of control group,gene expressions of AREG and EREG were 0.55 ± 0.09 vs.0.99 ± 0.09,0.67 ± 0.10 vs.1.02 ± 0.02,protein expressions of EREG were 0.54 ± 0.09 vs.1.04 ± 0.13,all P ＜ 0.05.For LoVo cells,expressions of AREG (both on mRNA and protein level) and EREG (on protein level) were significantly up-regulated versus those of control group,gene expression of AREG were 1.87 ± 0.39 vs.0.93 ± 0.23,protein expressions of AREG and EREG were 3.09 ±0.73 vs.1.11 ±0.21,1.53 ±0.19 vs.0.97 ± 0.23,all P ＜0.05.The regulating effect of AREG and EREG mRNA expression by FⅦa in HT-29 and LoVo cells could both be partly blocked by knocking down TF expression.For HT-29 cells,activation of EGFR pathway induced no significant TF mRNA expression,F Ⅶ mRNA expression was not detected.However,for LoVo cells,activation of EGFR pathway induced significantly higher mRNA expressions of both TF and FⅦ,expressions were 1.53 ± 0.23 vs.1.00 ± 0.23,53.20 ± 6.08 vs.1.00 ± 0.15,all P ＜0.05.Conclusion:In colon cancer cell LoVo,when activated,TF/FⅦa pathway and EGFR pathway could interact through upregulating the other pathway's effectors,and mutant KRAS might play a critical role in the two pathways'cross talk.