Vilà M R, Nicolás A, Morote J, de I, Meseguer A
Centre d'Investigacions en Bioquímica i Biologia Molecular (CIBBIM), Hospitals Universitaris Vall d'Hebron, Barcelona, Spain.
Cancer. 2000 Jul 1;89(1):152-64.
Renal cell carcinoma (RCC) comprises 85% of renal tumors and displays a great capacity to metastasize. The lack of diagnostic and prognostic markers complicates its early detection and in the majority of cases metastases are present at the time of diagnosis.
The current study reports on the identification of differentially expressed genes in RCC using random arbitrarily primed polymerase chain reaction (RAP-PCR).
Four genes were identified, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH), lactate dehydrogenase A (LDH A), human leukocyte antigen A (HLA A), and ferritin. GAPDH and HLA A were found to be overexpressed in 100% of the tumors and LDH A was increased in > 85% of the tumors analyzed compared with normal kidney counterparts. For GAPDH and LDH A higher protein levels in the tumors also were determined by Western blot analysis. Differential expression did not appear to correlate with gene amplification events as demonstrated by Southern blot analysis, indicating that regulatory mechanisms controlling the expression of these genes were altered. Finally, ferritin was judged to have a variable expression because it was decreased in approximately 50% of the tumors and augmented in 20%. The implications in proliferation and differentiation of all these genes were analyzed in RCC cell lines grown at different stages of confluency and additional information was obtained regarding expression of the GAPDH gene in proliferating primary cultures of normal and tumor cells derived from the same kidney samples.
The authors conclude that RAP-PCR is a useful technique with which to identify rapidly differentially expressed genes in a given system. In addition, they also conclude that GAPDH is a potent marker of cell proliferation in kidney tumor cells whose overexpression appears to be a late event in the development of RCC.
肾细胞癌（RCC）占肾肿瘤的85%，具有很强的转移能力。缺乏诊断和预后标志物使其早期检测变得复杂，并且在大多数病例中，诊断时已出现转移。
本研究报告了使用随机任意引物聚合酶链反应（RAP-PCR）鉴定RCC中差异表达基因的情况。
鉴定出四个基因，包括甘油醛-3-磷酸脱氢酶（GAPDH）、乳酸脱氢酶A（LDH A）、人类白细胞抗原A（HLA A）和铁蛋白。与正常肾组织相比，GAPDH和HLA A在100%的肿瘤中过表达，LDH A在超过85%的分析肿瘤中表达增加。通过蛋白质印迹分析也确定了肿瘤中GAPDH和LDH A的蛋白质水平更高。如Southern印迹分析所示，差异表达似乎与基因扩增事件无关，表明控制这些基因表达的调节机制发生了改变。最后，铁蛋白被判定具有可变表达，因为它在大约50%的肿瘤中减少，在20%的肿瘤中增加。在不同汇合阶段生长的RCC细胞系中分析了所有这些基因在增殖和分化中的作用，并获得了关于来自同一肾脏样本的正常和肿瘤细胞增殖原代培养物中GAPDH基因表达的更多信息。
作者得出结论，RAP-PCR是一种在给定系统中快速鉴定差异表达基因有用的技术。此外，他们还得出结论，GAPDH是肾肿瘤细胞中细胞增殖的有效标志物，其过表达似乎是RCC发展中的晚期事件。
