[Effect of epidermal chalones on the proliferation and differentiation of tumors of the lower lip in mice].

Methylcholanthrene solution was applied to the lower lip mucosa of 110 CC57 BR male mice during 2 months. Simultaneously with or after methylcholanthrene application part of mice was injected into the lower lip with ethanolic extract of rat skin containing epidermal G1 and G2 chalones. The remaining mice were injected with liver chalones or were left intact. Administration of the epidermal chalone produced the tumor growth retention, and the increased frequency of tumour regression, promoted tumor differentiation and decreased tumor invasion. The results indicate the possibility of using chalones as inhibitors of tumor growth.