N Zaki Mahdi - Department of Biology, College of Sciences, Mustansiriyah University, Baghdad, Iraq

Cancer is one of the most serious diseases facing humanity, so we urgently need to find a cure which is rarely harmful to the patient as much as possible. It has been approved that arginine deiminase (ADI) can hydrolyze the plasma arginine to citrulline. This hydrolysis activity and reduction in the amount of inter cellular argenine suppress lipopolysaccharide-induced nitric oxide (NO) synthesis. On the other hand arginine depletion, arresting the cell cycle at G۱ phase, Therefore, ADI has considered as a powerful anticancer agents. The aim of the current study was to investigate the lethal effects of ADI purified from Lactobacillus plantarum p۵ strain on murine mammary adenocarcinoma and vero cell lines. Anti-proliferative activity of ADI against murine mammary adenocarcinoma )AMN۳) cell line was evaluated after different incubation time (۳, ۶, ۲۴, ۴۸ and ۷۲ h) of exposure to ۱ µg/mL of ADI compared with Vero (none cancer cell line ) transformed cell line with same conditions. Autophagy process in cancer cells was recognized after three hours of incubation with ADI which was clearly observed in AMN۳ cell line under inverted microscope. First stages of programmed cell death (apoptosis) pathway was only observed in AMN۳ cells after ۲۴ h of incubation with ADI and this process continued with the time until they reached to last stages of apoptosis after ۷۲ h of incubation. The results of the current study showed that the AMN۳ cell line was auxotrophic for arginine because it couldn't produce it in the presence of enzyme which had a robust activity to kill these cancer cells, but Vero none cancer cell line was survive in the presence of ADI because it had the ability to produce arginine.

AMN۳, Arginine Deiminase, Autophagy, Lactobacillus plantarum p۵, Vero