Abstract
Content of androgen receptor, retention of injected testosterone and karyotype of SC115, androgen-dependent tumor, were compared with those of CS2, an androgen-independent subline derived from SC115. Although Bmax was less than that of SC115, androgen receptor was present in the cytosol and the nuclear extract from CS2. To examine the ability for androgen retention, a large amount of testosterone was injected into tumor-bearing mice, and the amount of androgen in the crude nuclear and postnuclear fractions of tumors was compared. In both fractions, retention of injected androgen was higher in the SC115 than in the CS2. Since most of the injected testosterone was not metabolized in the tissues and the injection of testosterone 5α-reductase inhibitor showed no significant influence on the growth rate of the SC115, intracellular active androgen was assumed to be testosterone in these tumor cells. As the CS2was tetraploid, the androgen independency of the CS2 seems to be related to chromosomal changes.
