Expression of CD44 adhesion molecules in nonpapillary renal cell carcinoma and normal kidneys.

摘要

OBJECTIVES: To analyze the relationship between the alterations in the expression of the CD44 gene in nonpapillary renal cell carcinoma (RCC) and several clinicopathologic factors. METHODS: The expression of the CD44 gene in 10 human RCC cell lines, 60 nonpapillary RCC tumor samples, and 15 normal kidney samples was investigated by reverse-transcription polymerase chain reaction (RT-PCR) using a set of primers capable of amplifying all CD44 variant isoforms. The results were analyzed with respect to several clinicopathologic factors. RESULTS: Nine of the 10 human RCC cell lines predominantly expressed the standard CD44 isoform (CD44s); CD44v10 was the major isoform in the 10th RCC cell line. The 15 normal kidney samples revealed the identical CD44 gene expression pattern; that is, CD44s, CD44v8-10, and CD44v10 were detectable in normal kidneys, and among them, CD44s was expressed most dominantly. In the 60 nonpapillary RCC samples, CD44s, CD44v8-10, and CD44v10 were the major isoforms in 46 (77%), 11 (18%), and 3 (5%) cases, respectively. Furthermore, the incidence of the predominant expression of CD44v8-10 in high-stage RCC was significantly higher than that in low-stage RCC. CD44s was more frequently expressed as a major isoform in clear cell RCC than in other histologic types of RCC. CONCLUSIONS: The results of this study show that the alternative splicing pattern of CD44 gene in RCC is different in each histologic type of RCC and suggest that CD44v8-10 upregulation in the progression of nonpapillary RCC is important.