The Expression And Clinical Significance Of MYBL2 In Gastric Adenocarcinoma

BackgroundGastric cancer(GC)is globally one of the most common cancer and the third leading cause of cancer-related deaths currently.In 2015,more than 670,000 people were diagnosed as GC,nearly 500 thousand people died from GC in China.The age standardized incidence rate of GC is 27.10/10 million people.GC is the most common tumor of digestive system in China.Because of the late clinical presentation and atypical symptoms,and the lack of high sensltive and specific biomarkers for clinical screening and early diagnosis,nearly 2/3 of GC patients were diagnosed as advanced GC with poor prognosis.Morover,GC is a complex disease arising from the interacton of environmental and host-associated factors,the complex biological and genetic heterogeneity of GC is also a key contributor to GC’s high mortality.MYBL2 is a member of MYB oncogene family which encodes a class of transcription factors.Its transcription level has been shown to be tightly regulated during the cell cycle by an E2 F dependent mechanism.In late G1 /S phase,MYBL2 transcription level is higher,suggesting that it is involved in activating genes including DNA topoisomerase II and cyclin B1.MYBL2 is also involved in DNA damage repair,spindle formation,affecting the process of cell cycle.It has also been shown to play a role in prevention of apoptosis by activating APo J,Bcl-2 and other antiapoptotic genes.Furthermore,recent publications have shown it to be overexpressed in a number of malignancies,such as breast cancer,colorectal cancer acute myeloid leukemia.Its expression level is associated with poor clinical prognosis.MYBL2 plays a key role in the regulation of gene expression,participates in the process of cell apoptosis,cell senescence and tumorigenesis.However,there are few reports of MYBL2 in gastric cancer.In this study,the levels of MYBL2 m RNA was measured in 45 cases of fresh frozen gastric adenocancinoma tissues and adjacent tissues using RT-PCR.The statistical analysis showed that there was a significant difference between the two groups.On this basis,the expression of MYBL2 protein was detected by immunohistochemistry in 74 cases of paraffin embedded gastric adenocarcinoma tissues and adjacent tissues.The value of MYBL2 in the occurrence,development,diagnosis,prognosis and treatment of gastric cancer were explored further.ObjectiveThe purpose of the study is to detect the expression of MYBL2 in gastric adenocarcinoma tissues and paracancerous tissues,and explore the relationship between the expression of MYBL2 level with clinicalpathological characteristics and prognosis in GC patients.Methods1)Clinicalpathological datas of GC patients were collected.2)The levels of MYBL2 m RNA was measured in 45 cases of fresh frozen gastric adenocancinoma tissues and adjacent tissues using RT-PCR.3)The expression of MYBL2 protein was detected by immunohistochemistry in 74 cases of paraffin embedded gastric adenocarcinoma tissues and adjacent tissues.4)The results of the experimental datas were analyzed by SPSS17.0 software.The difference of MYBL2 m RNA expression between cancer and adjacent tissues was performed by paired T test.The relationship between MYBL2 expression and clinicalpathological characters was analyzed by chi-square test.Survival curves were eatimated by Kaplan-Meier method,and were compared by Log-rank method.Multivariate COX regression model were used to explore the associations of patient outcome and characteristics.Results1)The expression level of MYBL2 m RNA in gastric cancer tissues was higher than that in adjacent tissues(P =0.0008).2)The expression level of MYBL2 protein in gastric cancer tissues was higher than that in adjacent tissues(P =0.000).3)The expression of MYBL2 m RNA and protein was related to the Lauren type,the degree of differentiation and lymph node metastasis.4)The expression of MYBL2 protein was correlated with the prognosis)of gastric adenocarcinoma patients,and the PFS was shorter for those with low MYBL2 expression level(P<0.05).Although 0S in patients with higher MYBL2 expression was shirter,it has not statistically significant(P=0.153).COX multivariate regression analysis showed that the expression of MYBL2 protein and tumor p TNM stage were independent prognostic factors of gastric adenocarcinoma.Conclusion1)The expression of MYBL2 m RNA and protein in gastric adenocarcinoma tissues was higher than that in adjacent tissues.2)The expression of MYBL2 protein was related to the type of Lauren,the degree of differentiation,and lymph node metastasis.3)The MYBL2 expression is associated with poor prognosis in gastric adenocarcinoma patients.The higher expression level of MYBL2 protein,the higher pathological stage,the shorter PFS.