Lai S, Benedict W F, Silver S A, El-Naggar A K
Department of Pathology, the University of Texas, M.D. Anderson Cancer Center, Houston 77030, USA.
Hum Pathol. 1997 Jun;28(6):693-7. doi: 10.1016/s0046-8177(97)90178-7.
Alteration of the retinoblastoma (RB) gene, located on chromosome 13q14, has been implicated in the pathogenesis and biological behavior of several human cancers. We investigated the RB gene status by Western blotting and immunohistochemical analysis, as well as loss of heterozygosity (LOH) at the RB locus in 21 primary human renal neoplasms (including 3 oncocytomas). In only 1 of 21 tumors was there a discrepancy between Western blot and immunochemical staining. Overall, LOH was noted in 6 of 12 informative cases. However, only one of the tumors with LOH at the RB locus had loss of RB protein expression by both Western blot and immunohistochemical analysis. Loss of RB function was found in 4 of 18 carcinomas and in none of 3 oncocytomas as determined by absent RB nuclear staining in tumor cells. LOH at chromosome 13q14 was more noted in high-grade, DNA aneuploid, high-stage tumors and in patients with poor outcome. These results imply that (1) there is likely another tumor-suppressor gene on chromosome 13 involved in renal carcinogenesis, (2) LOH at chromosome 13q loci may be associated with aggressive behavior, and (3) the loss of RB function may have a role in a subset of renal carcinomas.
位于13q14染色体上的视网膜母细胞瘤（RB）基因的改变与几种人类癌症的发病机制和生物学行为有关。我们通过蛋白质免疫印迹法和免疫组织化学分析，以及对21例原发性人类肾肿瘤（包括3例嗜酸细胞瘤）中RB基因座杂合性缺失（LOH）情况进行了研究。在21例肿瘤中，只有1例蛋白质免疫印迹法和免疫化学染色结果存在差异。总体而言，在12例信息充分的病例中有6例出现了LOH。然而，在RB基因座出现LOH的肿瘤中，只有1例通过蛋白质免疫印迹法和免疫组织化学分析均显示RB蛋白表达缺失。通过肿瘤细胞中RB核染色缺失确定，在18例癌中有4例发现RB功能缺失，而3例嗜酸细胞瘤中均未发现。13q14染色体上的LOH在高级别、DNA非整倍体、高分期肿瘤以及预后较差的患者中更为常见。这些结果表明：（1）13号染色体上可能存在另一个参与肾癌发生的肿瘤抑制基因；（2）13q基因座的LOH可能与侵袭性行为有关；（3）RB功能缺失可能在一部分肾癌中起作用。
