RB PROTEIN ALTERATION IN HEPATOCELLULAR CARCINOMA (HCC)

初步研究表明，Rb肿瘤抑制因子的突变 在某些与乙肝病毒相关的人肝细胞癌中可发现该基因 (肝癌)；然而，这些突变在RB基因组中的位置 还没有确定。在本研究中，Rb基因的异常 用单链构象多态方法分析外显子12-23 (SSCP)使用五个重叠的片段，每个片段为129至337个核苷酸。 对5株人肝癌细胞系进行了研究。(所有突变或 在其他人类癌症中报道的Rb基因缺失包括 外显子12-23的部分。)。用细胞总RNA合成c DNA； 然后用聚合酶链式反应(PCR)扩增cdna片段。 P标记的引物，用SSCP进行分析。 在HLE和HLE细胞系中发现Rb基因在外显子17-21处缺失 HLF，并定位于细胞系Hep3B的外显子20-21。检测的外显子是正常的 在细胞系PLC/PRF/5和HU-7中。这些缺失(或剪接位点 Rb基因的突变(外显子跳过)似乎在 在某些情况下发生肝癌，正如在其中三个细胞中观察到的那样 台词。其中两个细胞系似乎具有正常的外显子12-23，尽管 尚未排除杂合缺失或外显子跳过的可能性。这个 这两个细胞系中Rb的明显缺乏变化可能反映了 肿瘤发展的异质性。Rb基因的异常不会 似乎与整合的乙肝病毒的存在或缺失有关- 这些细胞系中的DNA。

Preliminary studies have shown that mutations of the RB tumor suppressor gene can be found in some HBV related human hepatocellular carcinomas (HCC); however, the locations of these mutations within the RB genome have not been determined. In the present study, abnormalities of the RB gene were analyzed within exons 12-23 by single-strand conformation polymorphism (SSCP) using five overlapping segments of 129 to 337 nucleotides each. Five cell lines derived from human HCCs were studied. (All mutations or deletions of the RB gene reported in other human cancers have encompassed portions of exons 12-23.). Total cellular RNA was used to synthesize cDNA; cDNA fragments were then amplified by polymerase chain reaction (PCR) using p-labeled primers and analyzed by SSCP. Deletion in the RB cDNA were found in exons 17-21 in cell lines HLE and HLF, and in exons 20-21 in cell line Hep3B. The exons examined were normal in cell lines PLC/PRF/5 and HUH-7. These deletions (or splice-site mutations with exon-skipping) in the RB gene appear to play a role in hepatocarcinogenesis in some cases, as observed in three of these cell lines. Two of the cell lines appeared to have normal exons 12-23, although a heterozygous deletion or exon-skipping has not yet been ruled out. The apparent lack of alterations of RB in these two cell lines may reflect the heterogeneity of tumor development. The abnormalities of RB gene does not appear to be correlated with the presence or the absence of integrated HBV- DNA in these cell lines.