Expression And Function Of Long Non-coding RNA IRAIN In Multiple Myeloma

Background: Multiple Myeloma(MM),a common malignancy in hematology,is also feared by many people.The absolute number of patients suffering from this disease originated from abnormal plasma cell cloning is constantly increasing,and the current medical water is still no way to cure MM,so we must pay attention to the breaking of MM.It has been found that lncRNA is closely related to tumor,and lncRNA can play the role of proto-cancer/tumor suppressor genes.LncRNA presents specific disorders in tumor cells and is also released from tumor cells,so monitoring the expression of lncRNA may be able to diagnose tumors and judge the prognosis of tumors.The 3’ non-translation region of lncRNA was found to bind to another class of highly concerned non-coding RNA,namely miRNA,and thus affect the regulation of miRNA on its target mRNA.This is also the most studied mechanism of lncRNA.Our research group has previously reported that the role of mir-125 b in MM is an oncogene.Bioinformatics predicted the target lncRNA of mir-125 b and found an lncRNA named IRAIN that has not been reported in MM.Therefore,we boldly speculated that IRAIN might be a tumor suppressor gene in MM.Objective: Firstly,the expression of IRAIN in MM was studied.Then the expression of IRAIN in MM cells was regulated and the cell proliferation and apoptosis ability were detected.Finally,the targeting relationship between IRAIN and mir-125 b was verified,and whether the function of IRAIN in MM cells was related to mir-125 b was discussed.Methods: IRAIN expression in plasma of 35 MM patients and MM cell lines(MM.1S,U266 和 RPMI-8226)was detected by RT-qPCR.CCK8 and flow cytometry respectively verified the changes in the proliferation and apoptosis abilities of MM cells(U266 and RPMI-8226)that down-regulated the expression of IRAIN.Down-regulated the expressions of IRIAN and mir-125 b in MM cells(U266 and RPMI8226),and then detected the expressions of mir-125 b and IRAIN,respectively.Luciferase reporter gene assay verified whether IRAIN was the target gene of mir-125 b,and whether it could eliminate the effect of knockdown IRAIN on the apoptosis activity ofU266 cells after down-regulating the expression of mir-125 b.Results: the expression of IRAIN in plasma of MM patients and MM cells was down-regulated.Knockdown IRAIN can promote MM cell proliferation and inhibit MM cell apoptosis.Knockdown of IRAIN can up-regulate the expression of mir-125 b,while knockdown of mir-125 b can also up-regulate the expression of IRAIN,IRAIN is the target gene of mir-125 b.Mir-125 b inhibitors can partially eliminate the inhibitory effect of knockdown of IRAIN on the apoptosis of MM cells.Conclusion: the expression of IRAIN in MM was down-regulated.IRAIN can inhibit MM cell proliferation and promote apoptosis.IRAIN promotes the apoptosis of U266 cells by adsorbing miR125 b.