Proteomic Analysis of Mitochondrial Proteins on the Mechanism of Apoptotic Under Amorphophallus konjac Tuber (KONJAC) Extracts in Gastric Cancer Cell

Objectives: We have analyzed the influence of Amorphophallus konjac tuber (KONJAC) extracts on protein expression of mitochondrial in cell line SGC-7901, identified those differentially expressed by mass spectrometry, and built a network of differentially expressed proteins using software. This provided the basis for a study of the molecular mechanisms of the anti-gastric cancer effects. Method: The cell viability was evaluated by cell counting kit-8. Cell apoptosis assay was used to detect cell apoptosis. Two-dimensional gel electrophoresis and MALDI-TOF-MS analysis was applied to identify the differentially-expressed mitochondrial protein treatment with or without KONJAC extracts. Ingenuity Pathways Analysis (IPA) software was to analysis an interacting protein. Result: Proliferation of SGC-7901 cells was reduced and early apoptosis increased after treatment with KONJAC extracts. Two-dimensional gel electrophoresis and MALDI-TOF-MS analysis showed that 682 protein spots in control group and 643 protein spots in the KONJAC extract treated group. Twenty proteins were identified that showed 10 up-regulated and 10 down-regulated proteins in these arrays. Bioinformatic IPA network analysis showed that ubiquitin-conjugating enzyme 2(E2) was located in the center of the network. Thus, the inhibition of cell proliferation and promotion of apoptosis by KONJAC extracts may be through ubiquitin conjugating enzyme-mediated mitochondrial apoptotic pathways. Conclusion: These results indicate that KONJAC extract-induced apoptosis and inhibit proliferation in SGC-7901 cells is mediated by pathways involving in mitochondrial apoptotic, gene transcription, cell cycle, oxidative stress response and energy metabolism. KONJAC extracts could be promising as a treatment for gastric cancer.