RESUMO
To investigate the effects of cordycepin on proliferation and invasion of pancreatic cancer stem cells (Pan CSC) and its mechanisms, MTT assay was used to investigate the effect of cordycepin on proliferation of Pan CSC. Inverted microscope was used to observe the morphologic change of cells. Propidium iodide staining methods was employed to observe the cell apoptosis. Cell scratch method was used to detect the ability of migration of Pan CSC in each group. RT-PCR and Western blot were used to determine the expression of apoptosis gene and epithelial-mesenchymal transitions (EMT) gene. The growth of Pan CSC was inhibited by cordycepin in a dose-and time-dependent manner, with IC50 107.364 and 48.472 μmol·L-1 at 24 and 48 h, respectively. Moreover, the cell migration was inhibited at the same time. RT-PCR and Western blot results showed that cordycepin decreased the expression of Bcl-2 and activated pro-apoptotic gene levels such as Bax,p53, caspase-3. Furthermore, cordycepin reduced the expression of EMT genes by up-regulation of E-cadherin and down-regulation of N-cadherin. Cordycepin has the ability to inhibit Pan CSC proliferation and invasion by activating p53 pathway as well as suppressing the EMT. This study provides a new basis for inhibition of pancreatic cancer stem cells in the treatment of pancreatic cancer.
RESUMO
The phytase was extracted from solid state leavening of Trichoderma Viride LH374.The crude product was purified by(NH_4)_2SO_4 precipitation,gel filtration and ion exchange chromatography.The purified phyatse was 13.3 times of the raw products,and the extraction ration was 27.1%.The study on the enzymology of phyatse showed that the optimal temperature and pH were 55℃ and 6.0,respectively.The Km value of the phytase was 0.15mmol/L.