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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Apoptosis, Arginase, Arginine, Argininosuccinate Synthase, Carcinoma, Hepatocellular, Caspase 3, Cell Cycle, Cell Line, Tumor, Cell Proliferation, Cell Survival, Enzyme Induction, Humans, Ki-67 Antigen, Liver Neoplasms, Models, Biological, Pancreatic Neoplasms, Protein Engineering, Recombinant Proteins.
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Does bioengineered arginase I increase caspase-3 expression of hepatocellular and pancreatic carcinoma cells despite induction of argininosuccinate synthetase-1? Context: Hepatocellular and pancreatic carcinomas are often auxotrophic for L-arginine, a semi-essential amino acid. The purpose of this study was to investigate cancer cell death using a significantly more active, cobalt-substituted bioengineered arginase. Panc-1, a human pancreatic carcinoma cell line, and Hep 3B, a human hepatocellular carcinoma cell line, were exposed to L-arginase. Flow cytometry was used to measure expression of Ki-67, caspase-3, and argininosuccinate synthetase-1 (ASS-1) 4 days after treatment. An MTT assay measured proliferation. The Student t test determined statistical significance. Viability decreased by 31% +/- 2% for Panc-1 cells (P < .0001) and 34% +/- 1% (P < .0001) for Hep 3B cells after treatment. Both cell lines demonstrated a 4-fold increase activated caspase-3 expression after high dose treatment (P < .01), and 5-fold increase in ASS-1 expression (P < .002). Ki-67 expression did not vary in Hep 3B cells but decreased for Panc-1 cells (P < .015). The 50% inhibitory concentration was 8-fold higher for Panc-1 cells than for Hep 3B cells (P < .03).
assistant
Increased ASS-1 expression by these cells, in order to increase L-arginine concentration, is inadequate, suggesting a mechanism by which arginine depletion can be used in multimodality therapy for arginine-dependent cancers. Final Decision: yes