GENETIC INSTABILITY IN MICROSATELLITE SEQUENCES IN PROSTATE-CANCER

Mutations in microsatellite sequences, especially expansion in the num ber of di- and trinucleotide repeats, have been implicated as the caus e of several heritable disorders, including fragile X syndrome and myo tonic dystrophy. We examined the possibility that a similar mutation m echanism might be involved in human prostate cancer. Our findings indi cate that mutations in microsatellite sequences are frequent in prosta te cancer. Six of thirty patients (20%) had an allele gain in at least one microsatellite sequence; three patients (10%) had allele gains in multiple loci. The new alleles were present in the tumor DNA, but not in the normal DNA. Although we did not detect mutations in the androg en receptor microsatellite sequences, it is likely that this type of m utation affects other genes important in prostate cancer, thereby prom oting tumor development and progression.