DIFFERENTIAL RESPONSE OF HUMAN-MELANOMA AND EHRLICH ASCITES-CELLS IN-VITRO TO THE RIBOSOME-INACTIVATING PROTEIN LUFFIN

The cytotoxicity and inhibitory effect on proliferation of the type I ribosome-inactivating protein luffin purified from the seeds of Luffa aegyptiaca were investigated both in human metastatic melanoma cells a nd in murine Ehrlich ascites tumour cells. Results indicate that luffi n from the seeds of Luffa aegyptiaca is cytotoxic to the cell lines te sted, with approximately 10 times greater potency in Ehrlich cells. Lu ffin was found to induce an increase in cytosolic oligonucleosome-boun d DNA in both melanoma and Ehrlich ascites tumour cells, the level of DNA fragmentation in the former cell line being higher than in the lat ter. Experiments with melanoma cells indicate that an increase in cyto solic nucleosomes could be supportive of apoptosis as the type of cell death induced by luffin, (C) 1998 Lippincott Williams & Wilkins.