Inclusion of New Microsatellite Repeats in Allelic Loss Analysis Excludes Retention of Heterozygosity in the Renal Cell Carcinoma Critical Region in 3p21

A variety of human cancers, including renal cell carcinoma (RCC), show frequent heterozygous deletion events in 3p21.3. An approximate 400-kb segment from within 3p21.3 is suspect of harboring a tumor suppressor gene, as it is homozygously deleted in three lung cancer cell lines and heterozygously deleted in virtually all lung tumors. Loss of heterozygosity (LOH) studies of this segment are hampered by the absence of highly informative markers. We have identified several new nucleotide repeats that map within this region, and have used these to complement our previous LOH studies in RCC. Our present analysis clearly shows that the common region of homozygous deletions in the lung cancer cell lines is always contained within the smallest region of overlap of heterozygous deletions in RCC.