Background: A number of molecular changes observed by varied conventional methods, including loss of heterozygosity (LOH) on chromosome 3, have been associated with primary lung cancer. To further define the locus of chromosome 3p allele loss in lung cancer, we performed LOH study by using innovative laser capture microdissection and WAVE DNA Fragment Analysis.
Material/methods: Thirty-eight paired specimens from patients with adenocarcinoma of the lung were used for this study. Formalin-fixed, paraffin-embedded tissue from normal stromal cells or lymphocytes and adenocarcinoma were collected using laser capture microdissection. DNA was extracted and amplified by PCR using six polymorphic DNA markers for chromosome 3. PCR products were analyzed by both gel electrophoresis and WAVE DNA Fragment Analysis.
Results: LOH at 3p22-24 was found in tumor cells from twelve out of thirty-eight patients (32%) when analyzed by WAVE DNA Fragment Analysis and LOH was found in tumor cells from nine out of thirty-eight patients (23%) when analyzed by gel electrophoresis. LOH was found in normal control from one out of thirty-eight patients.
Conclusions: 1. Our results suggest putative tumor suppressor gene(s) is present in a region at 3p22-24, which may play a role in carcinogenesis of lung cancer. 2. Laser capture microdissection is essential tool for defined LOH studies. 3. WAVE DNA Fragment Analysis is an accurate, sensitive and automated tool for analysis of DNA fragments.