Bcl-2转录抑制因子1在胃癌中的表达及其生物学功能

Expression of Bcl-2 transcription inhibitor 1 in gastric cancer and its biological function

摘要:

背景与目的 失巢凋亡效应分子Bcl-2转录抑制因子1（Bit1）在胃癌组织中存在异常表达，Bit1在胃癌中功能及作用机制如何值得研究。本研究旨在进一步观察Bit1在胃癌组织中的表达，并初步分析其对胃癌细胞生物学行为的影响。方法 用Western blot检测20例原发性胃癌患者癌组织及癌旁组织手术标本中Bit1蛋白的表达；将胃癌BGC-803细胞分别转染Bit1 shRNA慢病毒载体或空病毒载体后，以无处理的野生型BGC-803细胞为空白对照，用细胞免疫荧光实验验证转染效率与Bit1沉默效果，并分别用细胞划痕实验、Transwell侵袭实验、细胞增殖实验及TUNEL实验检测细胞侵袭、迁移、增殖及凋亡情况。结果 Western blot结果显示，与对应癌旁组织比较，Bit1在胃癌组织中蛋白表达水平明显上调（P<0.01）。免疫荧光结果显示，转染成功且Bit1被有效沉默。细胞行为学实验显示，与空白对照细胞比较，转染Bit1 shRNA后的BGC-803细胞的划痕愈合率明显降低、侵袭细胞数量明显减少、细胞增殖活性明显减弱、晚期凋亡细胞数明显增加（均P<0.05）；转染空载体的BGC-803细胞以上细胞行为学指标与空白对照细胞间的差异均无统计学意义（均P>0.05）。结论 Bit1在胃癌中表达上调，并与胃癌细胞的恶性生物学行为密切相关，其有可能是与胃癌发生、发展、预后相关联的生物标志物及潜在治疗靶点。

Abstract:

Background and Aims Anoikis effector Bcl-2 transcription inhibitor 1 (Bit1) is abnormally expressed in gastric cancer tissue, the function and mechanism of Bit1 in gastric cancer is worth studying. This study was conducted to further examine the expression of Bit1 in gastric cancer tissue, and present a preliminary analysis of the effects of Bit1 on the biological behavior of gastric cancer cells.Methods The expressions of Bit1 in the surgical specimens of gastric cancer and corresponding adjacent tissue from 20 patients with primary gastric cancer were determined by Western blot analysis. In gastric cancer BGC-803 cells after transfection with Bit1 shRNA lentivirus or empty lentivirus vector, with the untreated wild type BGC-803 cells as blank control, the transfection efficiency and Bit1 silencing effect were validated by immunofluorescence assay, and then, the invasion, migration, proliferation and apoptosis were Transwell invasion assay, scratch wound assay, CCK-8 assay and TUNEL staining assay, respectively.Results The results of Western blot showed that the expression level of Bit1 protein in gastric cancer tissue was significantly up-regulated compared with corresponding adjacent tissues (P<0.01). The results of immunofluorescence assay demonstrated the successful transfection and effective Bit1 silencing. The results of series of cellular behavior experiments revealed that the wound-healing rate, number of invaded cells, and proliferation ability were all significantly decreased, while the number of late apoptotic cells was significantly increased in BGC-803 cells with Bit1 shRNA transfection compared with blank control cells (all P<0.05); there were no statistical differences in these cellular behavior parameters between BGC-803 cells transfected with empty vector and blank control cells (all P>0.05).Conclusion The expression level of Bit1 is up-regulated in gastric cancer, and it is closely related to the malignant biological behavior of gastric cancer cells, suggesting that Bit1 may be a biomarker associated with the initiation, progression and prognosis as well as a candidate therapeutic target for gastric cancer.