Data_Sheet_5_Effects of Lactobacillus acidophilus KLDS1.0901 on Proliferation and Apoptosis of Colon Cancer Cells.XLS

Colon cancer is the most common type of malignant tumor. The cytotoxicity effect of lactic acid bacteria may be active by inhibiting cancer cell proliferation, producing anticancer compounds, and inducing apoptosis in cancer cells, but the mechanism is unclear. Our previous study revealed that Lactobacillus acidophilus KLDS1.0901 has good probiotic properties. In this study, We screened out the highest inhibition rate of L. acidophilus KLDS1.0901 and assessed the effects on the proliferation of HT-29, Caco-2, and IEC-6 cells. Then, the apoptosis mechanism of HT-29 cells was studied when treated with L. acidophilus KLDS1.0901. Results showed that L. acidophilus KLDS1.0901 inhibited the proliferation of HT-29 and Caco-2 cells in a dose-dependent manner and reached the maximum under the condition of multiplicity of infection (MOI) = 100 (rate of Lactobacillus to cells) at 48 h. With the increase in time and MOI, reactive oxygen species in HT-29 cells, the apoptosis rates of HT-29 cells were increased, and the amount of blue fluorescence of the cells was also increased after Hoechst 33258 staining. Furthermore, L. acidophilus KLDS1.0901 reduced the mitochondrial membrane potential of HT-29 cells. Notably, 1,133 differentially expressed genes were screened by transcriptomics research, including 531 up-regulated genes and 602 down-regulated genes. These genes were involved in the nuclear factor κB and PI3K-AKT signaling pathways related to the apoptosis of HT-29 cells. These findings suggested that L. acidophilus KLDS1.0901 has the potential to be used in the development of a new type of functional foods for adjuvant treatment of colon cancer.

结肠癌是最常见的恶性肿瘤类型。乳酸菌可通过抑制癌细胞增殖、产生抗癌化合物及诱导癌细胞凋亡发挥细胞毒性效应，但其具体作用机制尚未阐明。本团队前期研究表明，嗜酸乳杆菌（Lactobacillus acidophilus）KLDS1.0901具备优良的益生菌特性。本研究中，我们筛选得到抑菌活性最优的嗜酸乳杆菌KLDS1.0901，并评估了其对HT-29、Caco-2及IEC-6细胞增殖的影响；随后探究了嗜酸乳杆菌KLDS1.0901干预HT-29细胞后的凋亡调控机制。研究结果显示，嗜酸乳杆菌KLDS1.0901可呈剂量依赖性抑制HT-29与Caco-2细胞的增殖，并在感染复数（multiplicity of infection, MOI）=100（乳酸菌与细胞的比例）、干预48小时时达到最大抑制效果。随着干预时间延长与MOI值升高，HT-29细胞内活性氧水平、细胞凋亡率均显著上升，经赫斯特33258（Hoechst 33258）染色后，细胞的蓝色荧光信号强度也随之增加。此外，嗜酸乳杆菌KLDS1.0901可降低HT-29细胞的线粒体膜电位。值得注意的是，通过转录组学分析，我们共筛选得到1133个差异表达基因，其中上调基因531个，下调基因602个；上述差异基因参与了与HT-29细胞凋亡相关的核因子κB（nuclear factor κB）及PI3K-AKT信号通路。本研究结果表明，嗜酸乳杆菌KLDS1.0901有望用于开发辅助治疗结肠癌的新型功能性食品。