Medicine & Pharmacology, Veterinary Medicine; apoptosis; breast cancer; E. coli O157:H7; necrosis; Shiga-like toxin
Apoptosis and cell cycle arrest induction are targeted in the strategy of cancer therapy. Furthermore, bacterial toxin such as shiga-like toxin producing Escherichia coli has been suggested to be used as novel therapeutic agent against tumor malignancies either as independent anti-neoplastic agents or in combination treatment with chemo or radiotherapy. The aim of study was to investigate the potency of shiga-like toxin originated from local strains of E. coli O157:H7 as a new cancer therapy. As many as 10 culture cells T47D cell line were subjected by crude extract Shiga like toxin originated from five local isolates of E. coli O157:H7 i.e. KL-48(2), SM-25(1), SM-7(1), DS-21(4), and one isolate ATCC 43894 as a control with IC50 doses, respectively. The treatment was observed for 24 h, with two replications. An FITC-Annexin V and PI assay was used to observe apoptosis and necrosis effect, and simultaneously with cell cycle analysis using propidium iodide (PI) staining. Results of study showed T47D cell treated with Shiga-like toxin from local strain KL-48 (2) show the lowest viable cell, followed by SM 7(1), ATCC 43894, SM-25(1), DS-21(4) and contrary with control with each percentages as 15.20, 16.36, 22.17, 22.64, 33.86, and 94.36%, respectively. The results were also confirmed by the induction of the cell cycle arrest in phase G0-G1 as inactive phase, i.e. 66.41, 63.37, 61.52, 55.36 and 47.28% for T47D cell treated with toxin of KL-48(2), ATCC 43894, SM 25(1), SM 7(1), and DS 21(4), respectively. These results show tendency deleterious effect of Shiga-like toxin from local isolates on T47D cell, so that concluded they have potency as a good anticancer drug in Gb3-expressing breast cancer.