GENETIC ALTERATIONS OF ANDROGEN RECEPTOR GENE IN JAPANESE HUMAN PROSTATE-CANCER

In order to determine the significance of androgen receptor (AR) gene mutations for Japanese prostate cancers, we examined the entire coding region, from exon A to H, in 36 primary lesions, Five in stage A, 12 in stage B, six in stage C and 13 in stage D were subjected to PCR-SSC P analysis for genomic DNA and nucleotide sequencing. Mutations were d etected in five samples (14%). Two in stage D and refractory to anti-a ndrogen treatment showed mis-sense mutations. The other three showed c hanges in the length of the CAG repeat in exon A, with an expansion or a contraction of one repeat unit. However, no association with change s in AR function was indicated because they had not been refractory to hormone therapy. Since these latter three tumors were associated with microsatellite instability, the changes might have been the result of an impairment of mismatch repair. This study indicates that AR gene m utations pray a role, in only a subset of prostate cancer patients, in a treatment-refractory state.