Development of cartilage-like tissue from androgen-dependent Shionogi carcinoma 115 in androgen-depleted hosts.

Androgen-dependent Shionogi carcinoma 115 (SC115) is an undifferentiated medullary carcinoma showing a compact cell pattern. When SC115 was inoculated into castrated DS mice, slowly growing tumors containing cartilage-like tissue developed. The cartilage-like tissue showed close similarities in electron microscopical and histochemical features to normal cartilage tissue. The origin of the cartilage-like cells was investigated by using the electrophoretic pattern of 3-phosphoglycerate kinase (PGK, EC 2.7.2.3) as a marker. The original DS strain had B-type PGK, but we developed a congenic strain with A-type PGK. The SC115 tumor, which had B-type PGK, was grafted into castrated congenic mice with A-type PGK. The cartilage-like tissue that developed was divided into two parts; one part was used for PGK analysis and the other for histological examination. All histologically confirmed cartilage-like tissues had only B-type PGK, suggesting that SC115 cells may change into cartilage-like cells in androgen-depleted conditions.