Study On The Regulation Of Intracellular Calcium Signal On The Expression Of Cav1, Pdgfb And Ptgs2 Related To Tumor Metastasis

Objective:Based on poorly metastatic FBJ-S1 cells and highly metastatic FBJ-LL cells.which are obtained from FBJ-virus-infected mice osteosarcoma,our research group research on the mechanism underlying tumor metastasis by using modern molecular and cellular biology.GD1a suppresses tumor metastasis by positively regulating Cavl,Stiml expression and negatively regulating Hgf and other gene which are positively related with tumor metastasis expression in FBJ cells.Previous researchers found that calcium is closely related with cancer proliferation and metastasis.Stiml could regulate calcium concentration in the cell,indicating that FBJ-S1 cells has much more calcium concentration.The present work focuses on regulation of Cavl,Pdgfb,Ptgs2 expression by calcium signaling.Results:1.The results shown that calcium concentration is high in poorly metastatic FBJ-S1 cells.In FBJ-S1 cells by using the calcium channel blocker nifedipine,RNA silencing of voltage-dependent L-type calcium channel subunit alpha-1C(Cacnalc),cyclosporin A(a Calcineurin inhibitor),or INCA-6(a nuclear factor of activated T-cells[NFAT]inhibitor),and accumulating evidence indicating that Cavl is positively regulated at the transcriptional level through a novel calcium signaling pathway mediated by L-type calcium channel/Ca2+/Calcineurin/NFAT.This new finding has been confirmed in mouse NIH 3T3 cells and mouse lewis lung carcinoma cells.2.The results shown poorly metastatic FBJ-S1 cells are rich in platelet-derived growth factor-B(Pdgfb)mRNA level expression and our research group investigated whether Pdgfb is regulated by calcium.The results shown that Pdgfb expression was enhanced through Egrl by calcium ionophore,A23187,and using inhibitors described above and ds siRNAs directed to Calmodulin 1/2/3 and Calcineurin in addition to Cacnalc.The results indicates that Pdgfb is positively regulated by calcium signaling pathway.Nifedipine,cyclosporin A,INCA-6 suppress Pdgfb mRNA expression in mouse lewis lung carcinoma cells.3.The results shown that highly metastatic FBJ-LL cells are rich in Ptgs2(Cox2)that yields PGE2 and poor in PGE2 receptor 3(Ptger3,EP3).Endogenous GD1a and calcium signaling positively regulate EP3 mRNA level expression in but negatively regulate Ptgs2 mRNA level expression.Furthermore,Ptgs2 mRNA level expression is negatively regulated by EP3.Conclusion:1.A novel signaling pathway(Cacna1c/Ca2+/Calcineurin/NFAT)positively regulate Cavl expression.2.Cacnalc/Ca2+/Calmodulin/Calcineurin/NFAT/Egrl signaling pathway positively regulate Pdgfb mRNA level expression.3.Endogenous GD1 a positively regulate EP3 but negatively regulate Ptgs2 mRNA level expression.Furthermore,Ptgs2 mRNA level expression is negatively regulated by EP3.Cacnalc/Ca2+/Calcineurin/NFAT signaling pathway positively regulate EP3 but negatively regulate Ptgs2 mRNA level expression.