The Probiotic Bacteria Induce Apoptosis in Breast and Colon Cancer Cells: An Immunostimulatory Effect

Background: Uncontrolled cell proliferation and resistance to apoptosis are the main characteristics of cancer cells. Therefore, a substance with the capability to induce apoptosis in cancer cells could be known as an anti-cancer material. Probiotics are useful microorganisms that are crucial for the host’s health.Materials and Methods: In the present study, we evaluated the synergic effect of probiotic bacteria on the cytotoxic potency of cancer cells and apoptosis genes expression. Lactobacillus acidophilus and Bifidobacterium bifidum were cultured in MRS broth and then MTT test was performed on AGS, MCF-7, and peripheral mononuclear cells after treatment with the bacterial corpse. β-actin, Bcl2, Bax, TNF-α, and IFN-γ gene expression were evaluated in treated cell lines by real-time PCR method. Results: The result of cytotoxicity assay showed that bacterial corpse has higher cytotoxicity effects on cancer cells compared with normal cells. Results of gene expression demonstrated that Bcl2 and Bax gene expression significantly increased in cancer cells and TNF-α gene expression remarkably increased in normal cells as compared with the control group. Conclusion: Probiotic bacterial corpse can induce apoptosis in cancer cells. In normal cells, the immune system shifts responses toward Th1 and inflammatory cytokines.‎