Methylation Status And Clinical Study Of P57^KIP2 Gene In B Cell Non-hodgkin's Lymphoma

Objective:To investigate the methylation status of p57KIP2 gene in B cell non-Hodgkin's lymphoma(B-NHL)and its clinical significance,lay the foundation for finding new therapeutic targets.Methods:1.General information Collected from January 2012 to May 2016,36 cases of diagnosed NHL patients who admitted to Oncology ? Department in Shanxi Dayi Hospital,20 cases were male,16 were female,male to female ratio was 1:0.8,19-74 years old,the median age was 51 years.All of the patients were diagnosed by lymph node biopsy,which had definite pathological morphology and immunohistochemical diagnosis.The diagnosis was based on the standard of 2008 WHO lymphoid tissue tumor.Among them,B-NHL 32 cases,T cell non-Hodgkin's Lymphoma(T-NHL)4 cases.B-NHL included 21 cases of diffuse large B cell lymphoma(DLBCL),6 cases of mantle cell lymphoma(MCL),4 cases of marginal zone lymphoma(MZL)and 1 case of small lymphocytic lymphoma(SLL).T-NHL patients included 2 cases of T lymphoblastic lymphoma / leukemia(TLBL)and 2 cases of vascular endothelial cell lymphoma(AITL).10 cases of lymphadenitis were taken as control group.Treatment options and efficacy evaluation: DLBCL treatment was refer to "Guidelines for the diagnosis and treatment of diffuse large B cell lymphoma in China(2013 edition)",treated with R-CHOP(rituximab,cyclophosphamide,anthracyclines,vincristine and dexamethasone);MCL,MZL,AITL refer to NCCN clinical practice guidelines,MCL uses Hyper CAVD(A protocol consisting of cyclophosphamide,vincristine,adriamycin,prednisone alternate with B plan consisting of methotrexate,cytarabine)as the main treatment,MZL,AITL use CHOP treatment,T-LBL using BFM90 program.Efficacy evaluation: Reference to the criteria for the evaluation of the efficacy of WHO lymphoma.Follow up: All patients were followed up to January 1,2017,14 cases died,and 1 cases were lost.2.Specimen collection: The specimens of fresh sterile lymph node biopsy before treatment were collected and stored at-80?.3.Research method Extraction of DNA in lymph nodes of patients with tissue DNA extraction kit,using Sodium Bisulfite disposed DNA,then used methylation specific PCR(MSP)combined with denatured high performance liquid chromatography(DHPLC)test p57KIP2 gene methylation.4.Statistic treatment Application of SPSS22.0 software for statistical data processing: Using Mann-Whitney U test with independent samples comparison of methylation status of p57KIP2 gene between cases and controls;Fisher chi square test analysed the relationship between methylation status of p57KIP2 gene and clinical manifestations and laboratory tests;Kaplan-Meier survival analysis was used to analyze the survival of B-NHL patients.Difference was statistically significant(P < 0.05).Results:1.The methylation rate of NHL in patients with p57KIP2 was 27.8%(10/36),p57KIP2 gene methylation was not found in lymph nodes in 10 patients with lymphadenitis.p57KIP2 methylation rate in NHL tissues was higher than that of p57KIP2 in lymph node tissues.The detection rate of p57KIP2 methylation in patients with B-NHL was31.2%(10/32).Methylation of p57KIP2 gene was not detected in T-NHL.The p57KIP2 methylation rate in tumor tissues of patients with B-NHL was higher than that in T-NHL patients with tumor tissues in p57KIP2.Methylation of p57KIP2 gene in patients of DLBCL,MCL,MZL and SLL was 33.3%(7/21)?33.3%(2/6)?25%(1/4).Methylation of p57KIP2 gene was not detected in SLL.2.The methylation of p57KIP2 gene in high lactate dehydrogenase(LDH)group(8/15)was higher than that in LDH group(2/17),the difference was not statistically significant(P=0.021).The methylation of p57KIP2 gene was not significantly related with the patient's age,sex,lymph node involvement,B symptoms,bone marrow involvement,clinical stage,IPI score,Serum beta 2-MG level,Lymphocyte count,Hb count,Plt count,Ki-67 proliferation index and curative effect.(P>0.05),the difference was not statistically significant.3.There was no significant correlation between the methylation of p57KIP2 gene and the overall survival(OS)of the patients,and the difference was not statistically significant(P=0.905).Conclusion:1.The p57KIP2 gene methylation rate of NHL tumor tissue was higher than that of lymph node,and the methylation of p57KIP2 gene in lymphoma tissues had certain specificity;2.The methylation rate of p57KIP2 gene in B-NHL patients with high level of LDH was higher than that in LDH normal group,and the methylation status of p57KIP2 gene may be related to the tumor high load of patients with B-NHL;3.The methylation rate of p57KIP2 gene in B-NHL tumor tissue was higher than that of T-NHL gene in p57KIP2 tumor tissue.