[Determination of allelic losses in peritumor bronchial mucosa]

Lung cancer is the leading of death in both, women and men in the United States and many European countries. molecular cytogenetic and LOH analyses and LOH analyses of non-small cell lung cancer have shown somatic genetic alterations in a variety of chromosomes such as 1p, 3p, 5q, 8p, 9p, 11p, 11q and 17p. Putative tumor suppressor genes have been located in these lci. Allelic loss at 3p21, 9p21 and 5q21 has been also reported in premalignant epithelial lesions of the bronchus. We investigated 33 cases of NSCLC for LOH at 3p, 5q, 9p and 17p: 22 squamous cell and 11 adeno carcinomas. Normal lymphocytes, tumor cells and normal bronquial cells adjacent to the tumor were microdissected from paraffin embedded tissues. PCR amplification was performed utilizing the specific markers D5S299, D5S346, D3S1300, D9S157, D9S171 and D17S799. Our results show that within the NSCLC tumor cells, LOH was more frequently found at the 5q21 locus (75% of the informative cases), the 3p21 locus (48%) and 17p. Within the normal bronquial cells, LOH was found in 33% of the cases at 5q21 and 33% of the cases at 3p21. In conclusion our results show that LOH can be assessed in normal bronquial mucosae adjacent to NSCLC. We suggest that LOH at these loci may be present before the onset of the malignant growth.