Expression Of BIT1Mrna And Protein In Esophageal Squamous Cell Carcinoma And Its Clinical Significance

BackgroundEsophageal cancer is one of the most familiar malignant tumors in the world. Esophageal carcinogenesis is a multifactorial and multistage process. The imbalance of restraining or promoting apoptosis may play an important role in tumor genesis and growth. BIT1(Bcl-2inhibitor of transcriptionl) is found as a protein in2004, acts as a promote apoptosis factor induced by integrin. Some researches consider that BIT1protein is located in the intermembrane space at the physiological state. When the protein is released to cytoplasm, it can combine with AES(amino-terminal enhancer of split) and then induce anoikis. But the physiological function of BIT1isn’t clear. The latest research suggest that BIT1is located in the golgiosome and act as a antiapoptotic function. Currently, there is few different reports about the relation of the BIT1and tumor. The connection between BIT1and esophageal squamous cell carcinoma(ESCC) has never been discussed.To investigate the relationship between BIT1and ESCC, especially between BIT1and the metastasis of ESCC, we use reverse transcriptase polymerase chain reaction(RT-PCR) and immunohistochemistry SABC methods to detect the expression level of BIT1in the tissues of ESCC, tumor adjacent dysplasia and normal mucosa. Then we could supply a novel target spot and opportunity to the early diagnosis and the treatment of ESCC.Methods1. We used semiquantitative RT-PCR to check BIT1mRNA expression of30ESCC tissues which include10metastasis tissues, pairing adjacent atypical hyperplasia epithelium and pairing normal esophageal epithelium.2. We used immunohistochemistry SABC method to check BIT1protein expression of48ESCC which include30lymph node metastasis,47adjacent atypical hyperplasia epithelium and33normal esophageal epithelium.3. On the basis of the data type, We used ANOVA test, LSD test,t test and rank test.Resultsl.The expression of BIT1mRNA in esophageal tissuesThe expression of BIT1mRNA in carcinoma, adjacent atypical hyperplasia epithelium and normal esophageal epithelium were1.747±0.243、0.941±0.178、1.242±0.261, respectively. The expression level of BIT1mRNA in carcinoma was significantly higher than that in adjacent atypical hyperplasia epithelium and normal esophageal epithelium,respectively(P<0.05), but it had no significant difference between adjacent atypical hyperplasia epithelium and normal esophageal epithelium, (P>0.05).2. The relationship between the expression of BIT1mRNA and clinicopathological parametersThe expression of BIT1was not related to age, gender and the invasive depth of tumor(.P>0.05), but it was significantly related to lymph node metastasis,which in carcinoma withlymph node metastasis was significantly higher than that in carcimoma without lymph node metastasis (P<0.001); it was also significantly related to TNM stage,which in the TNM stage Ⅲ and Ⅳ was significantly higher than that in stage I and II (P<0.05).3. The expression of BIT1protein in esophageal tissuesThe overexpression rate of BIT1protein in carcinoma, adjacent atypical hyperplasia epithelium and normal esophageal epithelium were83%(40/48),36.17%(17/47)and6.06%(2/23), respectively. The expression of BIT1protein in carcinoma was significantly higher than that in adjacent atypical hyperplasia epithelium and normal esophageal epithelium,respectively(P<0.05), it in adjacent atypical hyperplasia epitheliumwas also significantly higher than that normal esophageal epithelium(P<0.05).4. The relationship between the expression of BIT1protein and clinicopathological parametersThe overexpression of BIT1protein was not related to age, gender and the histologic grade(P>0.05). But it was significantly related to the lymph node metastasis, TNM stage and the invasive depth of tumor. The expression of BIT1proteinin in carcinoma with lymph node metastasis was significantly higher than that in carcimoma without lymph node metastasis (P<0.05), which in the TNM stage Ⅲ and Ⅳwas significantly higher than that in stage I and II (P<0.05), which in the deep group was significantly higher than that in the superficial group (P<0.05). ConclusionsThe expression of BIT1mRNA and protein in ESCC was higher than that in adjacent atypical hyperplasia epithelium and normal esophageal epithelium, respectively, which in carcinoma withlymph node metastasis was significantly higher than that in carcimoma without lymph node metastasis, which in the TNM stage Ⅲ and Ⅳ was significantly higher than that in stage Ⅰ and Ⅱ, these suggested that the overexpression of BIT1in ESCC was closely associated to the invasion and metastasis of ESCC.