Anticancer Effect Of Lactobacillus Acidophilus And The Mechanism Of Induced Apoptosis In HT-29 Cells

Lactobacillus acidophilus is one kind of important probiotics, which has anticancer effect. Only part of the mechanism of induce apoptosis in HT-29 cells has been studied, while the majority still need further research. In this study, experiment in vitro culture of HT-29 cells and nude mice subcutaneous transplantation tumor model as two parts to explore the specific mechanisms of induced apoptosis in HT-29 cells.The main methods and results in our research are as follows:Chapter 2: Optimal conditions for L. acidophilus 6074 adhering to HT-29 cells were 48h, 100:1, pH6. Investigating the viability of HT-29 cells treated with L.acidophilus 6074 for 48h, the survival rate decreased by 57.25%, while there was no effect on human colon cells. After HT-29 cells exposed to L. acidophilus 6074 for 48h,many cavitation apoptosis morphology change were found by transmission electron microscopic.Chapter 3 : Further investigation confirmed that apoptosis-inducing ability of L.acidophilus 6074 by Rodamine 123. Results showed that HT-29 cells exposed to L.acidophilus 6074had time and dose dependenton inducing mitochondrial membrane potential(??m) loss. Using Western blot to detect the expression of Cytochrome C?Bax?Bcl-2?caspase-9 and caspase-3.Results showed that HT-29 cells exposed to L.acidophilus 6074 for 24h or 48h can up-regulated expression of Cytochrome C?Bax?caspase-9 and caspase-3,and down- regulated expression of Bcl-2.We can drowed a conclusion that the specific mechanismsof induceing apoptosis in HT-29 cells by L.acidophilus 6074 isapoptotic mitochondrial pathway.Chapter 4: To study the anti-cancer capacity of L. acidophilus 6074 in vivo, we established implant-tumor model in nud mice. Compared with the model group, the high dosegroup continuous 28 days has apoptosis effect, and through the mitochondrial pathway mediated apoptosis of HT-29 cells.In this project, experiment in vitro culture of HT-29 cells and nud mice subcutaneous transplantation tumor model show that the specific mechanisms of induced apoptosis in HT-29 cells isapoptotic mitochondrial pathway on HT-29 cells by L. acidophilus, which providing the theory for development of functional food or medicine, and so on.