Recently, the school of food and pharmaceutical engineering of Nanjing Normal University published a paper entitled "effect of Lactobacillus acidophilus CICC 6074 s? Layer protein on colon cancer HT-29 cell promotion and apoptosis" in the Journal of agricultural and food chemistry, the top magazine in the first area of agricultural and Forestry Sci. Associate Professor Guo Yuxing is the corresponding author, doctoral student Zhang Tao is the first author, and Nanjing Normal University is the first signing unit.
Research background:
Colon cancer is a kind of high incidence malignant tumor, which seriously threatens human health and life safety. The incidence rate of incidence of colon cancer is related to many factors such as diet, heredity, living habits and environment. Some studies have shown that long-term consumption of fermented dairy products can reduce the incidence rate of colon cancer and prevent or inhibit the function of colon cancer. However, the mechanism of reducing the incidence rate of colon cancer is not clear.
Lactobacillus acidophilus is an important member of Lactobacillus, which has an important role in regulating the intestinal immune system and enhancing the immunity of the body. To play these prebiotic functions, the premise is that Lactobacillus adheres to the intestinal epithelial cells. S-layer protein of Lactobacillus acidophilus is a kind of protein lattice structure with biological activity widely existing on the cell surface, which maintains the morphological structure of cells It plays an important role in protecting bacteria, mediating intestinal colonization and receptor recognition, inhibiting bacterial adhesion and immune regulation. Our previous research found that Lactobacillus acidophilus CICC 6074 S- layer protein has the functions of intestinal adhesion and immune system regulation. Since immunotherapy is considered as a potential cancer treatment method, we predict that S- layer protein may have potential cytotoxic effect on colon cancer cells. The purpose of this study is to explore the specific mechanism of Lactobacillus acidophilus cicc6074 S-layer protein inhibiting the growth of colon cancer cells.
Research content:
MTT assay showed that different concentrations of s-lamin significantly inhibited the proliferation of colon cancer HT-29 cells. Flow cytometry, RT-qPCR and Western blot showed that S-layer protein blocked HT-29 cells in G1 phase of cell cycle by up regulating p53, p21 and p16, down regulating the expression of CDK1 and cyclin B. The morphological changes of HT-29 cells were observed by transmission electron microscopy. It was found that the cells treated with s-lamin showed obvious apoptosis characteristics, including chromatin concentration, nuclear fragmentation and vacuole. Furthermore, it was found that s-lamin could induce HT-29 cell apoptosis through death receptor apoptosis pathway and mitochondrial pathway, and inhibit cell invasion by inhibiting PI3K / Akt pathway and FasL synthesis.
Conclusion:
The S-layer protein of Lactobacillus acidophilus cicc6074 can inhibit the proliferation of colon cancer HT-29 cells by blocking cell cycle, inducing apoptosis and mediating immune escape. S-layer protein may be a potential anticancer drug.
Original link: https://doi.org/10.1021/acs.jafc.9b06909
Brief introduction of corresponding author:
Guo Yuxing, female, member of the Communist Party of China, Changshu, Jiangsu Province, Nanjing Normal University, associate professor, master tutor. Research fields include probiotic development, dairy processing and food function factors. In 2016, the third level training object of the fifth "333 high level talent training project" of Jiangsu Province was supported by scientific research projects; the fifth batch of Nanjing Normal University's 100 young leading talents training program was selected in 2016; and the outstanding bone dry teachers of the blue project of Nanjing Normal University were trained in 2012. Visiting scholar, University of California, Davis. Member of the youth working committee of China Animal Products Processing Research Association; editorial board member of food research and development; member of Nanjing nutrition society; evaluation expert of National Natural Science Foundation and Zhejiang Natural Science Foundation. He has published more than 20 SCI papers in high-level academic journals such as J. agric. Food Chem and applied for and authorized 14 national invention patents. At present, there are two NSFC projects in charge of research. It has won many awards such as Zhejiang science and technology progress award, Jiangsu Science and Technology Progress Award and Ningbo Science and technology progress award.