This study investigated the enhanced antiproliferative effect of Lactobacillus casei strain Shirota (LcS) on geniposide actions in human oral squamous carcinoma HSC-3 cells. An MTT assay, flow cytometry, qPCR assay, western blot and HPLC were used for this study. The concentration of 1.0 × 10⁶ CFU/mL of LcS had no effect on the HOK normal oral epithelial cells and HSC-3 cancer cells. The 25 and 50 µg/mL geniposide concentrations also had no impact on HOK normal oral epithelial cells, but they had remarkable inhibitory effects on the growth of HSC-3 cancer cells, which are enhanced in the presence of LcS. By the flow cytometry assay, the LcS-geniposide-H (1.0 × 10⁶ CFU/mL LcS and 50 µg/mL geniposide)-treated HSC-3 cancer cells had the largest number of cells undergoing apoptosis compared to cells treated with other combinationsand obviously more than cells treated with only geniposide-H (50 µg/mL geniposide). Geniposide-H could increase the mRNA and protein expressions of caspase-3, caspase-8, caspase-9, Bax, p53, p21, IκB-α, Fas, FasL, TIMP-1, and TIMP-2 as well as decrease those of Bcl-2, Bcl-xL, HIAP-1, HIAP-2, NF-κB, COX-2, iNOS, MMP-2, and MMP-9 compared to other groups of cells, and LcS further enhanced these changes, with results that are greater than for the cells treated with only a high concentration of geniposide. The results of this study show thatLcS enhanced the antiproliferative effect of geniposide in HSC-3 cancer cells.
Keywords: Lactobacillus casei strain Shirota; antiproliferative effect; geniposide; human oral squamous carcinoma HSC-3 cells.