dihydroteleocidin-b and debromoaplysiatoxin

Topics: Alkaloids; Animals; Cell Adhesion; Cell Aggregation; Cell Transformation, Neoplastic; Enzyme Induction; Humans; Isomerism; Lactones; Lyngbya Toxins; Marine Toxins; Mice; Mollusk Venoms; Neoplasms; Ornithine Decarboxylase; Phorbols; Tetradecanoylphorbol Acetate

Three potent tumor promoters of different classes, 12-O-tetradecanoylphorbol-13-acetate, dihydroteleocidin B, and aplysiatoxin, and two moderate tumor promoters, mezerein and debromoaplysiatoxin, enhanced the frequency of appearance of cadmium-resistant Chinese hamster lung cells when the cells were exposed to cytotoxic levels of CdCl2. With these compounds, the activity to induce cadmium-resistant cells correlated well with the potency of tumor-promoting activity. Cadmium resistance, which persisted after removal of the tumor promoters, was associated with the overproduction of metallothionein I messenger RNA. The amplified metallothionein I genes were shown by Southern blotting experiments. The relevance of the gene amplification caused by tumor promoters is discussed in relation to cancer development and progression.

Topics: Alkaloids; Animals; Cadmium; Carcinogens; Cell Line; Cricetinae; Cricetulus; Diterpenes; Gene Amplification; Genes; Lactones; Lung; Lyngbya Toxins; Metallothionein; Mollusk Venoms; Phorbol Esters; Terpenes; Tetradecanoylphorbol Acetate

Topics: Alkaloids; Animals; Carcinogens; Cell Adhesion; Cell Differentiation; Cocarcinogenesis; Enzyme Induction; Female; Lactones; Lyngbya Toxins; Mice; Neoplasms, Experimental; Ornithine Decarboxylase; Skin Neoplasms