Local probiotic Lactobacillus brevis downregulates LPAR1 and LPAR2 gene expression and reduces invasion of MDA-MB-231 and MCF-7 breast cancercell lines

Introduction: Breast cancer (BC) is the second leading cause of cancer deaths in the world. Studies suggest that the lysophosphatidic acid (LPA) gene is the cause of invasion and metastasis in malignant cancers, including BC. In addition, the PI3K/ PAK1/ ERK cascade in cancer cells helps metastatic BC. It has been observed that LPA can stimulate reactive oxygen species production, which is an important mediator of LPA to stimulate the migration of BC cells and activate the PI3K/ PAK1/ ERK signaling pathway. Methods: This study aimed to evaluate the Lactobacillus brevis probiotic supernatant’s effectiveness in reducing LPA expression in BC cell lines. MCF-7 and MDA-MB-231 cell lines were treated with supernatant of local Lactobacillus brevis for 24 and 48h. mRNA expression levels of LPAR1 and LPAR2 genes were evaluated by qRT-PCR. Furthermore, an invasion assay was performed to assess these cell lines’ invasion rate following treatment. Results: The results indicated a remarkable decline in the survival rate of treated cells. LPAR1 and LPAR2 gene expression declined in MDA-MB-231 and MCF-7 cells. Moreover, the invasion rate of these cells was reduced following treatment. Conclusion: Considering Lactobacillus brevis supernatant’s cytotoxic effects on cancerous cells, this bacteria could be thought of as a promising application for a possible treatment approach with fewer adverse reactions. However, more research is obviously needed. In the future, probiotics could be used in conjunction with currently available therapies.