Experimental Study On The Expressions, Significances And Relationships Of HIF-1α, PTEN, P53, VHL And FIH-1 In Colorectal Carcinoma

CarcinomaObject:Our research was to detect expression of HIF-1α (hypoxia-inducible factorlalpha),VEGF(vascular endothelial growth factor),CD34 and PCNA(proliferating cell nuclear antigen) in colorectal cancerous tissue and adjacent tissue,and explore the role of HIF-1α in angiogenesis and Proliferation of colorectal carcinoma.Methods:Semiquantitative RT-PCR assay was employed to detect the expression of HIF-1α mRNA, VEGF mRNA in 42 patients with colorectal carcinoma;Expression of PCNA and CD34 was measured by SP immunohistochemistry;Spearman rank correlation was used to analyze the correlation between them.Results:Expression level of HIF-1α and VEGF in colorectal carcinoma was significantly higher than that in adjacent tissue (t=12.47,P=0.00;t=17.36,P=0.00);Both expression have no relatonship with location and gender,but has positive correlation with Dukes stage (t=6.43,P=0.00;t=-5.83,P=0.01);MVD and PI in cancerous tissue were higher than that in adjacent tissue,its level were high in Dukes stage C+D than that in Dukes stage A+B;Expression of HIF-1α mRNA was positively correlated with VEGF , MVD and PI( r=0.968,P<0.05;r=0.717,P<0.05;r=0.731,P<0.05);Expression of VEGF mRNA was also positively correlated with MVD(r=0.680,P<0.05).Conclusion:This results suggest that overexpression of HIF-1α and VEGF may play an important role in occurrence and development of colorectal carcinoma;HIF-1α , by inducing transcription of assosiated genes ,promote the angiogenesis and cellular proliferation of colorectal carcinoma. Altogether, HIF-1α is a possible target in colorectal carcinoma molecular therapy.Part two:To Value the Significance of HIF-1 a N PTEN> P53 Expression inColorectal Carcinoma and Correlationship among ThemObject: The purpose of this study was to research the role of HIF-1 a in colorectal carcinoma and correlationships between HIF-1 a and PTEN,P53.Methods: Using RT-PCR to detect the expression of HIF-1 a mRNA,PTEN mRNA,P53 mRNA in 42 patients with colorectal caicinoma.Results: The expression of HIF-1 a mRNA in colorectal carcinoma was higher than that in paired para-carcinoma 0=12.47^=0.00);The expression level of HIF-1 a mRNA was positive correlation with Dukes stage;The expression level of PTEN mRNA,P53 mRNA was lower in colorectal carcinoma than that in paired para-carcinoma(f=-8.25,P=0.00,f=-13.11,P=0.00);there were certain negative correlation between HIF-1 a and oncogene PTEN(r=-0.355,P=0.01,),P53 (r=-0.291,P=0.03).Conclusion: The overexpression of HIF-1 a may play an important role in the development and matastasis of colorectal carcinoma;The loss or mutation of anti-oncogene PTEN and P53.may lead to increased HIF-1 a in colorectal carcinoma.Part three:Expression of VHL mRNA and FIH-1 mRNA in ColorectalCarcinoma and Its Effect on HIF-1 a Protein LevelObject: To detect mRNA expressions of VHL and FIH-1 in colorectal cancer ,and explore their effect on HIF-1 a protein level.Methods: Semiquantitative RT-PCR assay was used to detect the expressions of VHL mRNA,FIH-l mRNA in 42 patients with colorectal cancer;Expression of HIF-1 a protein was measured by SP immunohistochemistry;Spearman rank correlation was used to analyze the correlation between them.Results: mRNA levels of VHL and FIH-1 in colorectal cancer were significantly lower than those in adjacent tissue (f=-10.14^=0.00;f=-15.26,P=0.00);Both expressions decreased as Dukes stage increased,and the expression in Dukes A+B stage were significantly higher than those in Dukes C+Dstage (f=2.84,P=0.01;t=-5.13^=0.00);Their expressions are no relationship with tumor location and gender.In 42 cases of colorectal cancer,positive rate of HIF-1 a protein was 69.1%(29/42),the expression in Dukes C+D stage(80.0%,24/30) was significantly higher than that in Dukes A+B stage (41.7%,5/12),(f=5.89rP=0.02);it was negative in adjacent tissue;Spearman rank correlation displayed that the expressions of VHL mRNA and FIH-1 mRNA were negatively correlated with the HIF-1 a protein level(r=-0.97,P<0.01;r=-0.66,P<0.01).Conclusion: The overexpression of HIF-1 a may play an important role in the development and matastasis of colorectal cancer;The decrease of VHL mRNA and FIH-1 mRNA expressions is closely correlated with the increase of HIF-1 a protein level in colorectal cancer.