Human prostate cancer cells (DU145) implanted into nude mice are deficient in DNase activity. After administration of a vitamin C/vitamin K3 combination, both alkaline DNase (DNase I) and acid DNase (DNase II) activities were detected in cryosections with a histochemical lead nitrate technique. Alkaline DNase activity appeared 1 hr after vitamin administration, decreased slightly until 2 hr, and disappeared by 8 hr after treatment. Acid DNase activity appeared 2 hr after vitamin administration, reached its highest levels between 4 and 8 hr, and maintained its activity 24 hr after treatment. Methyl green staining indicated that DNase expression was accompanied by a decrease in DNA content of the tumor cells. Microscopic examination of 1-μm sections of the tumors indicated that DNase re-activation and the subsequent degradation of DNA induced multiple forms of tumor cell death, including apoptosis and necrosis. The primary form of vitamin-induced tumor cell death was autoschizis, which is characterized by membrane damage and the progressive loss of cytoplasm through a series of self-excisions. These self-excisions typically continue until the perikaryon consists of an apparently intact nucleus surrounded by a thin rim of cytoplasm that contains damaged organelles.
|Pages (de - à)||109-119|
|Nombre de pages||11|
|journal||Journal of Histochemistry and Cytochemistry|
|Numéro de publication||1|
|Etat de la publication||Publié - 2001|