The Regulatory Roles And Its Correlative Mechanisms Of SPK1/S1P Signal In Chronic Myelogenous Leukemia Cell

1: BCR/ABL upregulates extracellular S1PObjective We investigated the bcr/abl fusion gene for its influence on SPK1/S1P signal pathway. Methods We transfected bcr/abl fusion gene to non-CML cells, and determined the change of SPK1 expression, activity and S1P secretion. S1P secretion in CML cell line K562 was assayed after pretreatment of BCR/ABL tyrosine kinase inhibitor STI571 and MAPK signal pathway inhibitor PD98059. Results The SPK1 expression, activity and S1P secretion were upregulated in non-CML cell line ECV304 and HL-60 which overexpress bcr/abl fusion gene. S1P secretion was decreased in K562 cells after treatment of STI571 and MAPK. Conclusion SPK1 expression, activity and S1P secretion can be upregulated by bcr/abl fusion gene through MAPK signal pathway.2: Cross-talk between S1P/S1P2 and MAPK Signal PathwayObjective To elucidate the relation between SPK1/S1P2 and MAPK sigal pathway in CML cells. Methods The S1P receptors expression in K562 cells and CML patients'peripheral blood mononuclear cells was determined by RT-PCR assay. The MPAK phosphorylation in K562 cells was determined after treatment of extracelluar S1P. The S1P secretion and MPAK phosphorylation were detected after treatment of DMS and S1P receptor agonist/antagonist. Results K562 cells and CML patients'peripheral blood mononuclear cells express S1P receptors. MAPK phosphorylation can be upregulated by extracellular S1P. DMS decreased S1P secretion and MAPK phsphorylation. S1P receptor 2 antagonist could also reduce MAPK phsphorylation. Conclusion There is cross-talk between MAPK and SPK1/S1P/S1P2 signal pathway.3: Influence of SPK1 gene interference in CML cells Objective To access the influence of SPK1 gene interference on proliferation and apoptosis in CML cells. Methods The adenovirus delivery of SPK1 gene interference was produced in 293 cells. Produced virus which was purifed by CsCl density gradient centrifugation was used to infect CML cells. The proliferation and apoptosis were detected. Results There were no influence on K562 proliferation, but the cells were promoted to apoptosis after SPK1 gene interference. Conclusion SPK1 gene interference can promote cell apoptosis.