Lysosomes in Malignant Skin Tumours
Journal/Book: (Reprinted from Nature Vol. 215 No. 5103 pp. 861-862 1967). 1967;
Abstract: Department of Immunology Institute of Dermatology St. John's Hospital for Diseases of the Skin London In the course of a study an the histochemistry of experimentally induced carcinogenesis in mouse skin I observed that a few applications of benzpyrene to the skin induced apparent activation of lysosomes in the epidermis1. I considered it of interest to examine the state of lysosomes in the final tumour stage especially in tumours classified as malignant. Tumours were induced in the skin of mice (A2G strain) by weekly paintings with 05 ml. of 08 per cent solution of benzpyrene in liquid paraffin. Tumours began to develop at between 30 and 40 weeks. The skin tumours were diagnosed as malignant when an histological examination the epidermal tumour cell masses had infiltrated into the underlying panniculus carnosus muscle2. Frozen sections of the tumour samples were cut by the "controlled-temperature freeze sectioning method" of Cunningham et al.3. Acid phosphatase was demonstrated by Holt's modification of the Gomori method4 5. In normal mouse skin an incubation time of 20 min in the Gomori medium produced well stained particles in the epidermis. These stained cytoplasmic particles have been shown to possess similar characteristics to the biochemically defined lysosomes6. After incubation for 1 h the intensity of staining for the enzyme was so great as to mask completely the presence of discrete cytoplasmic particles. . . .