Effects Of JAK2/STAT3 On The Expression Of HIF-1α、VEGF In A549 Lung Cancer Cell Line

Objective To observe the effects of JAK2/STAT3 on the expression of HIF-1ɑ and VEGF in human lung adenocarcinoma A549 cell line, in order to provide basic theory responsible for non-small cell lung cancer angiogenesis.Methods1. The expression levels of VEGF and HIF-1ɑ in human lung adenocarcinoma A549 cell line after treated with AG490 and CoCL2 for 48 hours were detected by Western blot(①Control;②AG490 50μmol/L;③AG490 100μmol/L;④CoCL2;⑤CoCL2+AG490 50μmol/L; ⑥CoCL2 +AG490 100μmol/L.)2.The mRNA expression levels of VEGF, HIF-1ɑ in human lung adenocarcinoma A549 cell line after treated with AG490 in different concentration for 48 hours were detected by RT-PCR.3.The protein expression of STAT3、P-STAT3 after transfected with STAT3 si RNA in A549 cells were detected by Western blot.The mRNA expression of HIF-1ɑ、VEGF after transfected with STAT3 siRNA in A549 cells were detected by RT-PCR.4.The protein expression levels of VEGF、STAT3、HIF-1ɑ、P-STAT3 in A549 cell line after treatment with IL-6(3.85nmol/L)for 24 hours were detected by Western blot.The mRNA expression levels of HIF-1ɑ、VEGF in A549 cell line after treatment with IL-6(3.85nmol/L)for 24 hours were detected by RT-PCR.Results1.After treated with AG490 for 48 hours, the protein levels of HIF-1α and VEGF were reduced in a concentration-dependent manner. In other words, the protein levels of HIF-1α and VEGF were decreased more with higher AG490 concentration. Hypoxia could increase the protein levels of VEGF and HIF-1α in human lung adenocarcinoma A549 cell line.2.According to the RT-PCR, the mRNA expression of HIF-1α and VEGF aftertreated with AG490 were reduced vs control. What’s more, after treated with AG490 for48 hours, the mRNA expression levels of HIF-1α and VEGF were reduced in a concentration-dependent manner.3. STAT3 si RNA could block STAT3 activation and down-regulated the mRNA expression of VEGF and HIF-1α in human lung adenocarcinoma A549 cell line.4.IL-6 can increase the protein and mRNA expression of HIF-1ɑ and VEGF, not the rotein expression of STAT3, in human lung adenocarcinoma A549 cell line.Conclusions1.Hypoxia could increased the protein levels of VEGF and HIF-1α in human lung adenocarcinoma A549 cell line.2. The JAK2/STAT3 pathway could regulated the mRNA and protein expression of VEGF and HIF-1α in human lung adenocarcinoma A549 cell line.