The Expression Of LMO4 In Diffuse Large B Cell Lymphoma And Its Significance

Diffuse large B cell lymphoma(DLBCL)is the most common lymphoid malignancy in adults and the most common type of non-Hodgkin's lymphoma(NHL).The rate is about 31% in Western countries,which is much higher in Asia than in Western developed countries.DLBCL has strong heterogeneity in various aspects,such as morphology,genetics and immunophenotype and so on.DLBCL is mainly concentrated in adult patients,with a median age of 60-70 years,but it may also occur in children clinically.Because of its polymorphism and strong heterogeneity,different patients of DLBCL have obvious differences to the same therapeutic regimen.About 40% of patients in the clinic can achieve sustained remission after receiving chemotherapy.Most patients have a good effect after the clinical application of rituximab(CD20 monoantibody),but at least 30% of patients still have no obvious effect,with high recurrence rate and poor prognosis.Studying the role of genes in the development of DLBCL can help to further understand its molecular mechanism and provide a theoretical basis for clinical treatment of DLBCL.LMO4(LIM-only protein 4)is a transcription factor containing the LIM domain,which is a new member of the LIM-only(LMO)subfamily.It was first discovered by the Maiya team in the animal's nervous system.The LMO protein is a nuclear expressed protein that plays an important role in DNA and protein interactions.The LMO4 protein has been widely studied in epithelial tumors.Wang et al found that LMO4 was highly expressed in about 55% of 153 patients with non-small cell lung cancer.Survival analysis showed that high expression of LMO4 was associated with poor prognosis.Tu et al found that the high expression of LMO4 in patients with psoriasis promoted the differentiation and proliferation of keratinocytes.Ding and colleagues found that LMO4 could regulate BCL-2 and promote the abilities of invasion and migration in HER2-positive breast cancer patients.In addition,high expression levels of LMO4 were associated with tumor size,histological grade and lower survival rates of HER2-positive breast cancer patients.This study revealed that LMO4 may play an important role in the genesis and development of human HER2-positive breast cancer.Nowadays,the expression of LMO4 in lymphoma and its significance are rarely reported at abroad,and none reported at home.Purposes: Exploring the expression of LMO4 in DLBCL and its clinical significance Method:(1)Immunohistochemistry(IHC)was used to detect the expression of LMO4 protein in 123 DLBCL and 60 reactive lymphoproliferative tissue(RLH).(2)Western blot analysis was used to detect the expression of LMO4 protein in diffuse large B-cell lymphoma cell lines SUDHL-4,LY-10,and normal peripheral blood lymphocytes.(3)Design three LMO4 gene interference siRNAs,namely siRNA-985,siRNA-1086, siRNA-873,and design a negative control group(siRNA-NC),which carries the 5' end FAM fluorescent group.Meanwhile,the blank control group(Mock)was estalished.(4)siRNA-LMO4 was separately transferred into LY-10 cells by LipofectamineTM3000. After transfection for 48 hours,the cells were collected and the protein amount of LMO4 was detected by Western Blot.(5)CCK8 method,invasion and migration experiments and flow cytometry were respectively used to investigate the changes of tumor cell proliferation,invasion, migration abilitied and apoptosis rate after transfection.Result:(1)Immunohistochemistry showed that the high expression rate of LMO4 protein in DLBCL was significantly higher than that in RLH(66.7% vs 23.3%,p<0.05).LMO4 expression was significantly correlated with tumor primary location, immunophenotype,IPI stage,and Ann Arbor stage(P<0.05),but there was no significant difference between LMO4 and other clinicopathological parameters.(2)LMO4 protein was highly expressed in diffuse large B-cell lymphoma cell lines SUDHL-4 and LY-10 compared with nomal peripheral blood lymphocyte.(3)The expression of LMO4 protein after transfection of 3 siRNA-LMO4 was down-regulated compared with siRNA-NC group and Mock group.Among which,siRNA-985 was the most effective.(4)The results of CCK8 assay showed that the absorbance values of siRNA-LMO4 group were significantly reduced compared with the negative control group and the blank control group,and the difference was much more significant with the passage of time,and the proliferative ability was significantly lower(p <0.05).(5)Transwell chamber assay showed that the siRNA-LMO4 group had lower invasive and migration ability than the negative control group and the blank control group, with statistical difference(p<0.05).(6)The results of flow cytometry showed that the apoptosis rate of siRNA-LMO4 group was significantly higher than that of the negative control group and the blank control group,with statistical difference(p<0.05).Conclusion:LMO4 had high expression levels in both DLBCL tissues and cells.After the expression level of LMO4 was down-regulated by siRNA,the apoptosis rate of DLBCL cells increased,while its proliferation,invasion and migration ability decreased,which indicated that LMO4 may play an important role in the genesis and development of DLBCL.The specific mechanism of the role of LMO4 in DLBCL remains to be further studied,which can provide a theoretical basis for targeted therapy of DLBCL.