Defective DNA repair genes in a primary culture of human renal cell carcinoma.
OBJECTIVE
Genomic stability is maintained by error-free DNA replication, repair, and recombination. To determine if repair genes contribute to genomic instability, we used a newly established cell line RCC-AJR (from clear-cell renal cell carcinoma) to examine hMSH2 (a mismatch-repair gene) and the gene encoding DNA beta polymerase (polbeta; a known contributor to base-excision repair).


METHODS
Coding sequences of hMSH2 and polbeta were amplified by the polymerase chain reaction (PCR) using RNA from RCC-AJR cells and matched normal kidney (NK) cells from the same patient. Nucleotide sequences of the PCR products were determined by the dideoxy-DNA method and direct sequencing. Expressions of repair genes were assayed by Western blotting. Microsatellite stability in RCC-AJR cells was assayed by alteration in (CA)n repeats.


RESULTS
In the RCC-AJR cells, we detected (a) a deletion of 1476 bp encoding 492 amino acids of hMSH2 cDNA, (b) an 87-bp deletion in the polbeta coding sequence, (c) truncated forms of hMSH2 and polbeta proteins, and (d) microsatellite instability.


CONCLUSIONS
This study provides evidence of alterations in hMSH2 and polbeta in the homogeneous cell population of an RCC-AJR tumor culture. The data indicate that repair genes may help preserve genomic stability in this cell line. We believe that this new primary RCC-AJR cell line will prove a useful model for investigating the cascade of genetic events in renal cells that leads to renal carcinogenesis.
Chen
H C
HC
Department of Cancer Biology/NB40, Lerner Research Institute, The Cleveland Clinic Foundation, OH 44195, USA.
Bhattacharyya
N
N
Wang
L
L
Recupero
A J
AJ
Klein
E A
EA
Harter
M L
ML
Banerjee
S
S
D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000473:pathology; D019951:DNA Polymerase beta / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins; D017353:Gene Deletion; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics* / Q000473:pathology; D018895:Microsatellite Repeats / Q000235:genetics; D051718:MutS Homolog 2 Protein; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; D019951:DNA Polymerase beta; C497172:MSH2 protein, human; D051718:MutS Homolog 2 Protein