Background:

Auxotrophic cancers are a leading cause of cancer-related deaths in the world. Because certain cancers are arginine amino acid auxotrophs,

Depletion of extracellular arginine using arginine deiminase (ADI) could be exploited to target such cancers. ADI is a potential anticancer agent against arginine auxotrophic cancers. It catalyzed the hydrolysis of L-arginine to L-citrulline and ammonia.

Purpose of research:

Our study aimed to find new sources of bacterial arginine deiminases from different soil environments in Egypt and their production as anticancer agents by recombinant DNA technology.

Methodology:

This study was designed to screen for ADI-producing bacterial species using a simple and convenient method using metallo-arginine agar selective medium (MAA) and the Nesslarization assay. The isolated samples were characterized based on morphological features, biochemical reactions, and DNA probe hybridization. The antitumor activity of ADI was analyzed by MTT cell viability assay using various cancer cell lines.

Results:

Bacillus cereus strain AH173 was the major ADI-producing bacterial isolate from various soil environments in Egypt. The enzyme of interest showed excellent anticancer activity against L-arginine amino acid auxotrophic cancers. The molecular weight of ADI was 48 kDa. The Km and Vmax values of ADI were 8.75 mmol/L and 8.78 µmol/min. The IC50 for bacterial ADI was 2.42 U/ml for liver cancer cell lines, 2.17 U/ml for melanoma cancer cell lines, 4.63 U/ml for colon cancer cell lines, and 4.53 U/ml for lung adenocarcinoma cell line (Calu-3), 3.12 vs PANC-1 pancreatic cancer cell line, 3.77 vs RCC4 renal cancer cell line