Investigation of the Effect of Lactobacillus Brevis Bacteria on the Expression of Rel A, IKB, and Casp3 Genes in HT29 Colon Cancer Cells

Studies have shown that probiotic bacteria inhibit the onset and progression of carcinogenesis through different pathways. Our objective in this study was to determine the effect of probiotic bacteria on the expression of growth-related genes Rel A, IKB, and Casp3 in HT29 colon cancer cells

In this study, the Lactobacillus brevis probiotic bacteria were first cultured, and after the supply of media conditioning, they were treated on HT29 cancer cells. The bacterium’s cytotoxic effect (bacterial T cells) was investigated using a microculture tetrazolium test (MTT). DNA was extracted from the treated cells, and a DNA Ladder assay was performed. Also, the 4′,6-diamidino-2-phenylindole (DAPI) test was performed to show cell apoptosis. After ribonucleic acid  (RNA) extraction and complementary DNA (cDNA) preparation to determine the mechanism of the effect of this bacterium on cellular signaling, the expression of growth-related genes Rel A, IKB, and Cas3 was measured using a real-time polymerase chain reaction (PCR) method.

The microculture tetrazolium (MTT) test showed that L. b bacteria inhibit HT29 cells’ proliferation, induce apoptosis in these cells, and inhibit Rel A gene proliferation by increasing IKB gene expression. Also, 4′,6-diamidino-2-phenylindole (DAPI), and DNA ladder assay following the treatment of HT29 cells regarding the mentioned bacteria showed qualitative changes in cell apoptosis. In addition, real-time polymerase chain reaction (PCR) results showed that L. b increased Casp3 gene expression in HT29 colon cancer cells (P=0.038).

Our findings indicate that L. b stimulates the apoptotic cell signaling pathway in HT29 colon cancer cells. It can be used as a new treatment strategy or therapy for colon cancer treatment.