The Expression Of MiR-150 And The Role On Cell Function In Conjunctival Mucosa-associated Lymphoid Tissue (MALT) Lymphoma

1.Background and ObjectiveMarginal zone B cell lymphoma of mucosa-associated lymphoid tissue,MALT lymphoma for short,accounting for 7% ~ 8% of all the B cell lymphomas,can be seen in the gastrointestinal tract,lung,thyroid,oral,ocular adnexal and other parts.Ocular MALT lymphoma in the eye is common in the elderly orbital malignant tumors,accounting for China's ocular adnexal lymphoma(OAL)for more than 80%.Ocular MALT lymphoma can occur in conjunctiva,lacrimal gland,eyelids,orbit,etc.In recent years,with the development of tumor detection technology,the change of people's living environment and living habits,the incidence of ocular MALT lymphoma has been risen,but the pathogenesis of this disease is not very clear.Therefore,the study of the pathogenesis of ocular MALT lymphoma has a crucial role in clinical diagnosis,treatment and prognosis.Micro RNAs(mi RNAs)are a class of non-coding small RNAs with about 18 to 25 nt,which are prevalent in plants and animals.In recent years,research on the expression of mi RNAs in tumor regulation has become a hot topic.Mi RNAs are further involved in a series of important life processes such as cell proliferation,differentiation,apoptosis and embryonic development through transcriptional regulation of targeted m RNAs by cleavage or transcriptional repression.Mi R-150 is a non-coding small molecule RNA consisting of 22 nucleotides located on human chromosome 19q13.33,which plays an important role in maturation,embryonic development and stem cell differentiation of B cells and T cells.In our previous study,we found that the expression of mi R-150 was significantly increased in conjunctival MALT lymphoma.The target protein of mi R-150 was detected by targetscan and combined with the expression profile of MALT lymphoma,we selected mi R-150 targeting tumor suppressor gene cbl-b.It is speculated that mi R-150 had a regulatory relationship with cbl-b and played an important role in the development and progression of conjunctival MALT lymphoma.Objective: To investigate the expressions of mi R-150 and cbl-b in MALT lymphoma,and to explore the effect of mi R-150 on the cell function and biological behavior of lymphoma cells and its potential molecular mechanism.2.Methods and Results(1)Detection of expressions of mi R-150 and cbl-b in conjunctival MALT lymphoma specimensIn this study,a total of 3 patients with MALT lymphoma admitted in the Department of Ophthalmology,Changzheng Hospital of Second Military Medical University from July 2016 to October 2016,all the patients were Han nationality,male,aged between 40-70 years old.All patients had excluded other diseases except conjunctival MALT lymphoma.All cases were treated by surgery,and confirmed as MALT lymphoma by postoperative pathology in our hospital,experimental tumors and control tissues were fresh specimens cut during the surgery.Real-time quantitative PCR was used to detect mi R-150 and cbl-b expressions in tumor and adjacent tissues.The results showed that the expression of mi R-150 was significantly up-regulated in the tumor tissues while the expression of cbl-b was down-regulated in the adjacent tissues.(2)Culture of B cell lymphoma cells(RPMI 8226)and detection of transfection efficiency of mi R-150 inhibitorRPMI8226 cells as a commonly used human B lymphoma cell line,was selected as the object of this study,and transfected with mi R-150 inhibitor to observe and record the transfection situation.The results indicated that DMRIE-C 1.5 ?L and micro RNA 2 ?L without serum had the best transfection outcome.(3)Inhibitory effects of mi R-150 on proliferation,migration,invasion and apoptosis of RPMI 8226 cellsIn this experiment,successfully transfected RPMI 8226 cell lines with mi R-150 inhibitor was used for investigating mi R-150 effect on cell function and biological behavior of RPMI 8226 cells.RPMI 8226 cells were divided into transfection negative control group and mi R-150 inhibitory group to perform CCK-8,Flow cytometry and Transwell assay.Results showed:(1)After transfected for 120 h,inhibition of mi R-150 could significantly inhibited proliferation of RPMI 8226 cells compared with the negative control group,there was significant difference between the two groups,P<0.001;(2)Compared with the control group and the negative control group,the apoptosis rate of mi R-150 inhibitor group was significantly increased(P<0.001);(3)Inhibition of mi R-150 could inhibit the migration and invasion of RPMI8226 cells(P<0.05).3.ConclusionThrough the above experiments,we concluded that: the expression of mi R-150 was significantly up-regulated in the conjunctival MALT lymphoma,while the expression of the tumor suppressor gene cbl-b in the conjunctival MALT lymphoma was significantly down-regulated;further in vitro studies indicated that inhibiting the expression of mi R-150 cells could have inhibitory effect on related biological function and characteristics of B cell lymphoma cell(RPMI 8226),indicating that mi R-150 may play an important role in the development of conjunctival MALT lymphoma,and its tumor suppressor target gene cbl-b is also expected to be a new target molecule for conjunctival MALT lymphoma.