Expression of CD44 adhesion molecules in nonpapillary renal cell carcinoma and normal kidneys.
OBJECTIVE
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.
Hara
I
I
Department of Urology, Kobe University School of Medicine, Japan.
Miyake
H
H
Yamanaka
K
K
Hara
S
S
Arakawa
S
S
Kamidono
S
S
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis*; D007668:Kidney / Q000378:metabolism*; D007680:Kidney Neoplasms / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020033:Protein Isoforms / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
D018960:Hyaluronan Receptors; D020033:Protein Isoforms