The Expression And Clinicopathological Significance Of APOBEC3B In Gastroenteropancreatic Neuroendocrine Neoplasm

Objective:This article aims to detect APOBEC3B(apolipoprotein B mRNA-editing enzyme catalytic polypeptide 3B),which reveals the expression of apolipoprotein B mRNA-editing enzyme catalytic polypeptide 3B in gastrointestinal pancreatic neuroendocrine tumors,and analyzes the expression and clinical pathological parameters(age,gender,tumor size,histological grade classification,lymph node metastasis,clinical stage,etc.).Additionally,this article explores the relationship between APOBEC3 B expression in gastroenteropancreatic neuroendocrine neoplasm(GEP-NEN)and clinicopathological significance were investigated.Method:(1)The expression of APOBEC3 B mRNA in 50 cases of gastrointestinal pancreatic neuroendocrine tumors was detected by RT-qPCR(real-time quantitative polymerase chain reaction)method.Twenty of the specimens with paraneoplastic tissue were selected as controls.(2)The expression of APOBEC3 B protein in 70 tissue samples from the first part of the experiment was detected by immunohistochemical staining,and the correlation between APOBEC3 B protein expression and mRNA expression was analyzed;after expansion of the specimen,156 cases of gastrointestinal pancreatic neuroendocrine were selected.The tumors were examined for the expression of APOBEC3 B in tumor tissues,and the relationship between APOBEC3 B and clinicopathological parameters related to gastrointestinal pancreatic neuroendocrine tumors was analyzed.Conclusion:(1)Of the 50 GEP-NEN specimens,9 were neuroendocrine tumor G1(NETG1)and 17 were neuroendocrine tumor G2(NETG2),and 13 were neuroendocrine carcinoma(NEC).There were 11 cases of mixed adenoendocrine carcinom(MANEC).The expression of APOBEC3 B mRNA in NETG1 and NETG2 was higher than that in NEC and MANEC(P<0.05),but there was no significant difference in the expression of APOBEC3 B mRNA between NETG1 and NETG2(P>0.05).There was no significant difference in the expression of APOBEC3 B mRNA between NEC and MANEC(P>0.05).(2)There was significant correlation between the expression of APOBEC3 B protein and the expression of APOBEC3 B mRNA,and the expression of APOBEC3 B protein was consistent with the mRNA expression(P<0.001).(3)After expanding the specimens,a total of 206 cases of immunohistochemical staining were performed,including 42 cases of NETG1,37 cases of NETG2,79 cases of NEC,and 48 cases of MANEC.The positive expression rate of APOBEC3 B protein in gastrointestinal pancreatic neuroendocrine tumors reached 45.6%,and showed different degrees of expression.The positive rate of APOBEC3 B protein in NETG1(81.0%)and NETG2(86.5%)was significantly higher than NEC(25.3%)and MANEC(16.7%),the difference was statistically significant(P<0.05);By contrast,no difference was found between NEC and MANEC(P>0.05),in NETG1 and NETG2.(4)Univariate analysis showed that the expression of APOBEC3 B protein was correlated with gender,age,site of tumor,histological grade,tumor size,clinical stage,lymph node metastasis,and vascular invasion.The difference was statistically significant(P<0.05),and the neuronal invasion was not significantly related to the expression of APOBEC3 B protein(P>0.05).(5)Multivariate analysis showed that tumor size(P<0.05)and histological grade classification(P<0.05)were independent influencing factors of APOBEC3 B protein expression in GEP-NEN patients,while gender,age,clinical stage,tumor site,lymph node metastasis and vascular invasion were excluded(P>0.05).Conclusion:(1)APOBEC3B mRNA and its protein were differentially expressed in gastrointestinal pancreatic neuroendocrine tumor tissues.APOBEC3 B protein is highly expressed in well-differentiated tumors(NETG1 and NETG2),suggesting that APOBEC3 B gene may be associated with the onset of neuroendocrine tumors and low expression in NEC and MANEC,further demonstrating that neuroendocrine and neuroendocrine cancers may differ.The pathogenesis of APOBEC3 B may have different roles in NET and NEC.(2)The expression of APOBEC3 B was related to tumor size and tumor histological grade classification.By contrast,gender,age,location of tumor,clinical stage,occurrence of vascular invasion,and lymph node metastasis didn't affected APOBEC3 B expression.