ABSTRACT
PURPOSE: Lactobacillus casei (L. casei) is known to exert anti-proliferation effects on many types of cancer cells. However, the effect of L. casei on liver cancer has not been reported. Accordingly, the aim of this study was to determine the anti-cancer effect of L. casei extract on Huh7 cells. MATERIALS AND METHODS: L. casei ATCC393 extract was prepared and purified. After the treatment of L. casei extract on Huh7 cells, cell viability, cell cycle arrest and cell death were analyzed by flow cytometry. The expression levels of tumor necrosis factor-alpha receptor 1 (TNFR1) and death receptor 3 (DR3) mRNA related with extrinsic apoptosis were assessed by reverse transcription polymerase chain reaction. Additionally, P21 and P27 cell cycle proteins as well as Caspase-3, -8, -9, phospho-Bad and Bcl-2 apoptosis proteins were analyzed by western blot analysis. To determine the effect of L. casei extract on cancer stem-like cells, we analyzed changes in side population fraction through flow cytometry. RESULTS: The cell viability of Huh7 cells treated with L. casei extract was decreased by 77%, potentially owing to increases in the rates of Huh7 cells arrested in the G2/M phase (3% increase) and that underwent apoptosis (6% increase). The expression levels of TNFR1 and DR3 mRNA, as well as P21 and P27 cell cycle proteins, were increased. Meanwhile, the expressions of caspase-8, -9, phospho-Bad and Bcl-2 proteins decreased. However, in the case of side population cells, no remarkable changes were observed. CONCLUSION: L. casei extract exerts a potent anti-tumor effect on the viability of liver cancer cells, although not on cancer stem-like cells.
Subject(s)
Humans , Apoptosis/drug effects , Carcinoma, Hepatocellular/pathology , Caspase 8/metabolism , Caspase 9/metabolism , Cell Cycle Checkpoints/drug effects , Cell Extracts/pharmacology , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Cyclin-Dependent Kinase Inhibitor p27/metabolism , Cytostatic Agents/pharmacology , Flow Cytometry , Gene Expression Regulation, Neoplastic/drug effects , Lacticaseibacillus casei/chemistry , Liver Neoplasms/pathology , Proto-Oncogene Proteins c-bcl-2/metabolism , RNA, Messenger/metabolism , Receptors, Tumor Necrosis Factor, Member 25/metabolism , Receptors, Tumor Necrosis Factor, Type I/metabolism , bcl-Associated Death Protein/metabolismABSTRACT
In a preliminary study, we found that benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (zVAD- fmk), unlike Boc-aspartyl(OMe)-fluoromethylketone (BocD-fmk), at usual dosage could not prevent genistein-induced apoptosis of p815 mastocytoma cells. This study was undertaken to reveal the mechanism underlying the incapability of zVAD-fmk in preventing this type of apoptosis. We observed that 14-3-3 protein level was reduced in genistein-treated cells and that BocD-fmk but not zVAD-fmk prevented the reduction of 14-3-3 protein level and the release of Bad from 14-3-3. We also demonstrated that truncated Bad to Bcl-xL interaction in genistein- treated cells was prevented by BocD-fmk but not by zVAD-fmk treatment. Our data indicate that BocD- fmk, compared to zVAD-fmk, has a certain preference for inhibiting 14-3-3/Bad signalling pathway. We also elucidated that this differential efficacy of BocD-fmk and zVAD-fmk resulted from the different effect in inhibiting caspase-6 and that co-treatment of zVAD-fmk and caspase-6 specific inhibitor substantially prevented genistein-induced apoptosis. Our data shows that caspase-6 plays a role on Bad/14-3-3 pathway in genistein-induced apoptosis of p815 cells, and that the usual dose of zVAD-fmk, in contrast to BocD-fmk, did not prevent caspase-6 acting on 14-3-3/Bad-mediated event.
Subject(s)
Mice , Animals , bcl-Associated Death Protein/metabolism , Signal Transduction/drug effects , Mitochondria/drug effects , Mastocytoma , Hydrocarbons, Fluorinated/pharmacology , Genistein/pharmacology , Enzyme Inhibitors/pharmacology , Cell Line, Tumor , Caspase 6/antagonists & inhibitors , Benzyl Compounds/pharmacology , Apoptosis/drug effects , Amino Acid Chloromethyl Ketones/pharmacology , 14-3-3 Proteins/metabolismABSTRACT
OBJECTIVE@#To observe the change of retinal ganglion cells (RGCs)and the expression of Bad after optic nerve injury, so as to study the changes of optic function level on morphology and molecular.@*METHODS@#The experimental models of optic nerve crush were established in fifty Wistar rats. At the different time after injuries (from one to twenty-eight day), the changes of RGCs were observed under microscope. Immunohistochemiscal technique and computer image analysis methods were performed to observe the changes of Bad in RGCs in rats.@*RESULTS@#The number of RGCs was reduced significantly according to partial lesion of optic nerve crush. An initial loss of RGCs densities was accelerated in one week after nerve crush, two weeks later the trend mitigated. After four weeks, no obvious change were observed. The expression of Bad increased in 3 days, reached peak in 5 days, and declined one week later. No obvious changes were observed after two weeks.@*CONCLUSION@#The expression of Bad lead to the loss of RGCs following optic nerve crush. This is the important reason of loss optic function. The identification on optic nerve injuries should be done at least four weeks later.