Detection of loss of heterozygosity in the APC tumor suppressor gene in nonpapillary renal cell carcinoma by microdissection and polymerase chain reaction.

The role of the APC (adenomatous polyposis coli) tumor suppressor gene in the genesis of nonpapillary renal cell carcinoma is addressed. The frequency of allelic deletion in the APC gene was analyzed using microdissection of the tumor specimens and a PCR (polymerase chain reaction)-based assay for the detection of intragenic loss of heterozygosity (LOH). Twelve of 29 carcinomas investigated were informative (41%). In five of these (42%) LOH was detected in the APC gene, LOH did not correlate with tumor grade or stage. This high frequency of intragenic LOH suggests an implication of the APC gene or a closely linked gene in the genesis of a subset of nonpapillary renal cell carcinoma. The use of a microdissection technique allows the reliable detection of tumor-specific LOH when using a PCR-based assay.