evaluation of l-methioninase as a targeted anticancer agent in colorectal cancer and renal cell carcinoma

The employment of l-methioninase (l-met), an enzyme degrading l-methionine, as a possible anticancer therapy has been provided that it selectively destroys cancer cells, which require methionine to grow. many tumor tissues have a limited capacity for methionine production and depend on exogenous supplies of this amino acid. therefore, they could be selectively attacked by methioninase-based treatment. the present study was carried out to investigate the effect of l-met on cancer cells, especially colorectal cancer (hct-116) and renal cell carcinoma (a498), and its potential as a therapeutic agent. various techniques, such as ammonium sulfate precipitation, dialysis, ion-exchange chromatography, and gel filtration chromatography, were employed in this study for enzyme purification of l-met. cytotoxicity testing was performed against hct-116 and a498 cells in the range of 25-200 µg/ml concentration by the mtt assay for viable cell quantification, total nuclear intensity (tni), and cell membrane permeability (cmp). the statistical analysis was done using one-way anova and dunnett's multiple comparisons test to compare multiple groups. the optimal temperature for enzyme activity was 37° c, with ph 7 offering the best enzyme stability. further investigation into incubation time revealed that a 48-hour period maximized enzyme yield. the enzyme was purified using a combination of ammonium sulfate precipitation, ion-exchange chromatography, and gel filtration, achieving a 4.6-fold increase in purity. characterization of the purified enzyme revealed a molecular weight of approximately 55 kda, with optimal activity at ph 7 and 37°c. the enzyme demonstrated strong potential for therapeutic applications, showing dose-dependent cytotoxicity against colorectal cancer (hct-116) and renal cancer (a498) cell lines, with significant inhibitory effects at concentrations as low as 25 µg/ml for colorectal cancer cells. the study highlights the potential of p. aeruginosa-derived l-met showed strong activity in colorectal cancer, while activity in renal cell carcinoma was lower or inconclusive.