DETAILED DELETION MAPPING AT CHROMOSOME 9P21 IN NONSMALL CELL LUNG-CANCER BY MICROSATELLITE ANALYSIS AND FLUORESCENCE IN-SITU HYBRIDIZATION

We examined 82 cases of primary non-small cell lung cancer (NSCLC) for loss of heterozygosity (LOH) at the chromosome 9p21-24 region using 1 6 microsatellite markers, A total of 52 tumors (63%) displayed LOH, an d 25 of these cases displayed LOH for all markers. Two cases had small hemizygous losses confined to the p16 gene and more distal markers, w hereas 3 cases had loss proximal to p16 and extended through marker D9 S126. This latter region has recently been described as another minima l region of loss at 9p21 in lung cancer, However, homozygous deletion of the p16 gene was observed in 18 of 85 cases, with only 5 cases havi ng large deletions extended into the D9S126 region, Furthermore, we di d not observe homozygous deletion at the 9p21 region that excluded the p16 gene, Fluorescence in situ hybridization (FISH) analysis using ge nomic probes spanning either the p16 or Hel-N1 (located at D9S126) gen e was performed in 14 tumors, The results from FISH correlated with th e chromosomal mapping data, suggesting that the p16 region is the majo r target of deletion at chromosome 9p21 in primary NSCLC. (C) 1997 Wil ey-Liss, Inc.