Loss of heterozygosity and microsatellite alteration in testicular tumors

Objective To study the loss of heterozygosity(LOH) and the microsatellite instability (MSI) involved in the development of human testicular tumor. Methods 22 primary testicular tumor DNA samples were examined for loss of heterozygosity(LOH) on chromosomes 3, 5, 9, 17, 18 and X and alteration of microsatellite repeats marker by means of polymerase chain reaction, 8 microsatellite repeats markers being used for the analysis of MSI. Results LOH on chromosome 9q33 34, 5q and 18q21 were observed in 45%, 43% and 25%, respectively. Difference between unrelated microsatellites for tumor and control DNA was detected in 8 of 22(36%) . LOH and/or MSI were observed in 17 of 22(77%) cases. Two cases showed alterations on 5 microsatellite loci, three cases showed alterations on 2 microsatellite loci and three cases on 1 microsatellite locus. 5 of 22(23%) patients showed replication error(RER). Conclusions Tumor suppressor genes on chromosome 9q and 5q, and microsatellite instability might play an important role in the development of human testicular tumor.