Genetic mutations enhance the production of Exotoxin A by Pseudomonas aeruginosa for use as a potential anticancer therapeutic agent

Abstract

Microbial proteins have emerged as promising anticancer agents for various cancer types. Pseudomonas aeruginosa derived‑Exotoxin A is a potent virulence factor that specifically binds to the α2‑macroglobulin cell receptor. It exhibits strong cytotoxicity and potential advantages over conventional cancer treatments due to its ability to penetrate cancer cell membranes and inhibit protein synthesis. In the present study, 20 P. aeruginosa isolates collected from micro‑ biological laboratories between October 2023 and January 2024 were characterized. The isolates were identified using classical biochemical tests, confirmed using an automated identification system, and classified into six groups based on SDS‑PAGE protein banding patterns. The gene encoding Exotoxin A was amplified in one isolate from each group using PCR, yielding a 367‑bp amplicon. To enhance the production of Exotoxin A, random mutations were introduced to the selected isolates using UV irradiation. Exotoxin A was then purified using column chromatography followed by dialysis, resulting in a product with a molecular mass of ~66 kDa as determined by SDS‑PAGE. The cytotoxic effects of crude and purified Exotoxin A were assessed against the MCF‑7 breast cancer cell line. MTT assay results revealed that the half‑maximal inhibitory concentration (IC50) of purified Exotoxin A from a wild‑type isolate was 4.9 µg/ml, whereas the corresponding mutant exhibited an IC50 of 3.6 µg/ml, indicating a 1.4‑fold increase in cytotoxic activity. The findings of the present study highlight the potential of microbial‑derived proteins in cancer therapy. However, further evaluation of these proteins is necessary to explore their therapeutic applicability.