[Studies of microsatellite instability and loss of heterozygosity at chromosome 17 in non-small cell lung carcinoma]

Abstract

Objective: To identify the presence of microsatellite instability (MI) and loss of heterozygosity (LOH) in non-small cell lung carcinoma (NSCLC).

Methods: Four microsatellite markers TP53(17p13.1), THRA1 (17q11.2-12), D17S579(17q12-21) and D17S855(17q21) were used to examine 35 cases of NSCLC tumor-normal paired tissues for MI and LOH at chromosome 17 using PCR based analysis.

Results: 22 of 35 tumors(63%) displayed MI or LOH. 14 tumors(40%) exhibited MI, 11 tumors(31%) exhibited LOH, while 3 tumors (9%) exhibited MI and LOH concurrently. The frequency of MI or LOH was obviously higher in the early-stage(stages I and II, 79%) than in the advanced-stage (stage III, 44%), P < 0.05. However, the frequency of MI or LOH had no significant difference between high-grade differentiated NSCLC tumors and low-grade ones, P > 0.05. No relationship was observed between the presence of MI or LOH and the histologic subtype of NSCLC, P > 0.05.

Conclusions: The results suggest that MI and LOH at chromosome 17 may play a significant role in the development of NSCLC. The high frequency of MI or LOH in the early-stage tumors indicates that these genetic alterations could occur early during NSCLC development.