Abstract: Objective To explore the effect of calcium release-activated calcium channel modulator 1(ORAI1) on the proliferation of colon cancer cell line SW480 and its mechanism. Methods The SW480 cells were infected with ORAI1 interference lentivirus . The expressions of ORAI1 mRNA and protein were confirmed by fluorescence quantitative PCR(FQ-PCR) and Western blotting. MTT、colony-forming test and doubling time were used to examined the proliferation of SW480.Flow cytometry was used to detect the periodic variation of SW480 . Confocal microscopy was used to detect the difference of SOCE (store-operated Ca2 + entry, SOCE) in each group. Meanwhile，Western blotting was used to detect the expressions of ERK1/2, p-ERK1/2 and CyclinD1 protein. Results After infected SW480 with ORAI1 interference lentivirus for 72h,significant fluorescence expression can be seen.Compared with the empty vector group and the control group,the expression of ORAI1 was lower (P<0.01),the cells grew slower(P<0.05),the colony-forming ability was decreased (P<0.01), the doubling time was delay(P<0.01)，the proportion of cells in G1 phase was higher(P<0.05) , the Internal flow peak of SOCE was lower(P<0.05), and the expressions of p-ERK1/2 and CyclinD1 proteins were deseased(P<0.01)． Conclusion ORAI1 may regulate the intracellular calcium concentration by SOCE, and further promote the proliferation of SW480 through MAPK signaling pathways.

Key words: ORAI1, SW480, proliferation, SOCE, MAPK pathway