The effect of kinetin, kinetin ribofuranoside and gibberellic acid upon cultures of skin and mammary carcinoma and cystic disease.

Kinetin and kinetin ribofuranoside have been tested on tissue cultures of adult human skin, breast carcinomas, and cystic disease of the breast. Outgrowths of epi thelium from skin cultures were retarded by kinetin and completely inhibited by kinetin ribofuranoside when treated with 1.0 mg. per cent. A concentration of 0.1 mg. per cent of kinetin had no effect on the extent or population of cells in the zone of epithelial outgrowth from skin. There was no effect from kinetin at either 0.1 or 1.0 nig. per cent on outgrowths of fibroblasts and epithelial cells from carcinomas and cystic disease. Kinetin ribofuranoside equally reduced the outgrowth of fibroblasts and epithelial cells at a concentration of 1.0 mg. per cent but had no effect at 0.1 mg. per cent on cultures of carcinomas and cystic disease. Gibberellic acid (0.1-2.5 mg. per cent) had no effect upon the outgrowths of fibroblasts or epithelium from tissue cul tures of adult human skin, breast carcinomas, or cystic disease of the breast.