title: Mechanism of sensitivity of cultured pancreatic carcinoma to asparaginase.
abstract: The effects of E. coli L-asparaginase on cultured human pancreatic carcinoma (MIA PaCa-2) have been studied. The enzyme (1 U/ml) inhibited growth and protein synthesis in both MIA PaCa-2 and PANC-1, another pancreatic carcinoma cell line, but had little or no effect on human breast carcinoma or melanoma cells. The inhibition of protein synthesis by E. coli L-asparaginase was largely reversed by L-glutamine but not by L-asparagine. The growth of both MIA PaCa-2 and PANC-1 showed absolute dependence on L-glutamine. These results indicate that the effect of E. coli L-asparaginase on cultured pancreatic carcinoma cells is exerted at least in part through its L-glutaminase activity. Although the addition of L-glutamine to the culture appeared to prevent cell death caused by L-asparaginase, it did not restore the ability of the cells to proliferate. Asparaginase derived from vibrio succinogenes, which is virtually free of L-glutaminase activity, was equally inhibitory to MIA PaCa-2 cell growth but did not affect protein synthesis. It is concluded that the inhibition of growth of cultured pancreatic carcinoma cells by E. coli asparaginase is a combined function of both its L-asparaginase and L-glutaminase activity.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001215:Asparaginase / Q000494:pharmacology*; D001216:Asparagine / Q000494:pharmacology; D001943:Breast Neoplasms / Q000378:metabolism; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects*; D002478:Cells, Cultured; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D004926:Escherichia coli; D005260:Female; D005973:Glutamine / Q000494:pharmacology; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D008545:Melanoma / Q000378:metabolism; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D010190:Pancreatic Neoplasms / Q000378:metabolism; D012334:RNA, Neoplasm / Q000096:biosynthesis*; D014733:Vibrio
chemical_list: D000596:Amino Acids; D004273:DNA, Neoplasm; D006023:Glycoproteins; D009363:Neoplasm Proteins; D012334:RNA, Neoplasm; D005973:Glutamine; D001216:Asparagine; D001215:Asparaginase