[Effect of epidermal chalones on the growth of transplantable tumors]

The ethanolic extract of rat skin contains epidermal G1- and G2-chalones which having been added to cell suspension of transplantable squamous-cell cornified carcinoma of mice cervix, inhibits its growth in recipients by 72,6 per cent. The same extract failed to inhibit the growth of transplantable mouse tumours of other histogenesis (hepatoma 22a, leukemia L-1210 and sarcoma 180). When added to cell suspension of transplantable carcinoma of mouse skin which had been anaplized during a long period of transplantation (over 10 years) this extract inhibits its growth by 39,2 per cent only.