人乳腺癌组织中核糖核酸酶抑制因子基因的表达分析

Analysis of Gene Expression of Ribonuclease Inhibitor in Human Breast Cancer Tissue

背景与目的:核糖核酸酶抑制因子(ribonucleaseinhibitor,RI)是一种多功能的酸性糖蛋白,人胎盘中富含RI。我们的前期研究表明,从人胎盘中提纯的RI能明显抑制小鼠某些实体瘤(S180肉瘤、Ca761乳腺癌和H22肝癌)的生长。本研究的目的是观察人乳腺癌组织中RI基因的表达水平。方法:采用RT-PCR及毛细管电泳(capillaryelectrophoresis,CE)法检测人乳腺癌组织中RImRNA的表达水平,采用Westernblot方法检测人乳腺癌组织中RI的含量。结果:与对照乳腺组织相比,乳腺癌组织RT-PCR产物的电泳条带较窄;乳腺癌组织Westernblot的斑点较小。乳腺癌组织RT-PCR产物毛细管电泳吸收曲线峰高及峰宽明显小于对照乳腺组织;乳腺癌组织和对照乳腺组织RT-PCR产物毛细管电泳吸收峰面积积分值分别是(3.320±0.365)×106和(4.385±0.880)×106,两组间比较有显著性差异(P<0.01)。结论:与正常乳腺组织相比,人乳腺癌组织中RImRNA表达水平明显降低,RI蛋白含量也明显减少,表明人乳腺癌组织中RI基因表达明显下调。

BACKGROUND & OBJECTIVE: Ribonuclease inhibitor (RI), which is ri ch in human placenta, is a multi-functional acidic glycoprotein. Our previous s tudies showed that the growth of some solid tumors (S180 sarcoma, Ca761 breast c ancer, and H22 hepatoma) could be significantly inhibited by RI extracted and pu rified from human placenta. This study was designed to observe the change of RI gene expression in human breast cancer tissue. METHODS: The expression level of RI mRNA was determined by reverse transcription-polymerase chain reaction (RT- PCR) and capillary electrophoresis (CE). The RI content was determined by Wester n blot analysis. RESULTS: The electrophoretic stripes of the RT-PCR products of the breast cancer tissues were narrower and the plaques of Western blot of the breast cancer tissues were smaller compared with the control breast tissues. The peak altitude and width of capillary electrophoretic absorptive curve of the RT -PCR product of the breast cancer tissue were clearly smaller than that of the control breast tissue. The capillary electrophoresis integral values of the abso rptive peak areas of RT-PCR product of the breast cancer tissue and the control breast tissue were (3.320±0.365)×106 and (4.385±0.880)×106, respectively. T he comparison between two groups reveals a remarkably difference (P< 0.01). CONC LUSION: The gene expression of RI is clearly down-regulated in human breast can cer tissue that the RI mRNA level is remarkably lower and RI content also reduce s significantly in human breast cancer tissue.