LIN28在膀胱癌和膀胱癌细胞系中的表达及意义

Expression and Significance of LIN28 in Bladder Cancer and Bladder Cancer Cell Lines

目的:探讨LIN28在膀胱癌组织和细胞系中表达情况,以及与microRNA初级Let-7g(pri-Let-7g)之间关系,推测其可能临床意义及对肿瘤进展的影响。方法:采用常规RT-PCR、miRNA转录、免疫荧光和免疫组化方法,检测LIN28 mRNA和pri-Let-7g表达,以及LIN28蛋白表达定位。结果:2例膀胱癌细胞系均表达LIN28 mRNA,T24表达较强,免疫荧光显示这两个细胞系均表达LIN28蛋白,阳性部位位于细胞胞质,T24荧光强度强于5637。所选10例膀胱癌和相应癌旁组织均表达LIN28 mRNA,二者并无明显不同,与临床分级也无明确关系。免疫组化显示癌组织LIN28表达阳性并定位于胞质,而癌旁正常组织LIN28表达为阴性。此外,两个细胞系pri-Let-7g表达较强,而癌和癌旁组织的pri-Let-7g表达强度无明显差异,需进一步检测其成熟Let-7g在这些组织中是否存在不同,以明确这些miRNA是否发生生物合成的转录后阻断。结论:明确T24和5637两个膀胱癌细胞系均可作为研究LIN28、Let-7与其相应靶基因关系的体外实验模型。尽管并不确定膀胱癌和癌旁组织LIN28、Let-7g表达强度与临床分级是否相关,但至少明确LIN28/LIN28在膀胱癌中表达,为探讨LIN28和Let-7在泌尿系统来源的其他恶性肿瘤中的作用提供借鉴和实验依据。

Objective：To investigate the expression of LIN28 and microRNA primary Let-7g （pri-Let-7g） in bladder cancer and bladder cancer cell lines, as well as to speculate its possible clinical significance and impact on tumor progression. Methods： RT-PCR and miRNA transcription were performed to detect the expression of LIN28 and pri-Let-7g in bladder tissue and bladder cancer cell lines^Immunofluorescence and Immunohistochemistry were used to detect the LIN28 protein location on bladder tissue and Cell lines. Results： LIN28 mRNA was detected in T24 and 5637 cell lines,and its level was higher in T24 than that of 5637. LIN28 protein was located in the cyto- plasm of T24 and 5637. The LIN28 mRNA and pri-Let-7g were expressed in 10 paired tissue samples,and signifi- cant differences were not existed in bladder cancer and adjacent normal tissues, respectively. Moreover, the obvious relationship between the clinical classification and the levels of LIN28 mRNA or pri-Let-7g was not indicated. The mature Let-7g should be detectd in further study to identify whether miRNA Let-7g occurred post-transcriptional block in miRNA biosynthesis. In addition,the pri-Let-7g was also expressed in T24 and 5637 cell lines. The immu- nohistochemistry results were indicated that LIN28 was positive in cancer tissues but was negative in adjacent nor- mal tissues. Conclusions..T24 and 5637 bladder cancer cell lines can be servedd as models to explore the relationship between LIN28 and Let-7 with its associated target genes in vitro. Although this relationship is not evident for the expression level of LIN28 or Let-7g and clinical classification,it is clear that LIN28/LIN28 is expressed in bladder cancer. This study will provide the reference and experimental dates for the other cancer of the urinary system.