Role Of Hedgehog Signaling Pathway In Angiopoiesis In-vitro Of Human Gastric Cancer SGC-7901Cells

Objective The incidence of gastric cancer in our country shows risingtrend, serious impacting on human health。The present study confirmed thatHedgehog(Hh) signaling pathway can promote the origination anddevelopment of various cancers by regulating cell cycle, adhesion,invasion,angiopoiesis and apoptosis. Glioma-associated oncogene homolog(Gli1) asthe key factor of the evaluation of the pathway activation has beenextensively studied. Platelet-derived growth factor(DPDGF-D) as a stronglypro-tumor-angiogenesis factor, has been shown abnormally high expressionin a various cancers. The Hh signaling pathway can regulate the expressionof PDGF-D to influence the angiopoiesis is not yet clear.In our stuy,we usecyclopamine(a special antagonist of Hh signling pathway) to treat withSGC-7901cells, The expressions of Gli1,PDGF-D and the ability ofangiopoiesis before and after treatment were analyzed to investigate the roleof Hh signaling pathway in angiopoiesis of human gastric cancer SGC-7901cells in vitro as well as the relevant mechanism.Methods SGC-7901and Human umbilical vein endothelial cell （HUVEC）wereculturedbyroutinemethod.SGC-7901cellsweredividedinto control group A and test groups B and C. The cells in group A wereuntreated， while those in groups B and C with cyclopamine at finalconcentrations of5and10μmol/L respectively，and further cultured for48h. The expressions of glioma-associated oncogene homolog（Gli1）andplatelet-derived growth factor D（PDGF-D）in SGC-7901cells of variousgroups were determined by IFA，while the ability of angiopoiesis before andafter treatment by tube formation assay and vasculogenic mimicry（VM）formation assay. The expressions of Gli1and PDGF-D at mRNA and proteinlevels were determined by RT-PCR and Western blot respectively，betweenwhich the relationship was analyzed.Results Gli1and PDGF-D were expressed in SGC-7901cells ofvarious groups. As compared with those in control group，the abilities ofangiopoiesis in vitro of SGC-7901cells in test groups showed adose-dependent decrease（P<0.05），while the expressions of Gli1andPDGF-D at mRNA and protein levels decreased significantly（P<0.05）.However，the expressions of Gli1at both mRNA and protein levels werepositively related to those ofPDGF-D，withr values of0.829and0.786respectively（P<0.05）.Conclusion cyclopamine can significantly suppress Gli1mRNA andprotein expression, thus reduce the formation of the structure of SGC-7901cells and HUVEC cells in vitro. Hh signaling pathway may promotethe angiopoiesis of tumor by regulating the expression of PDGF-D with Gli1.