Objective: To investigate the mechanism of cell cyclin-dependent kinase (KDM5B), a key enzyme driving all cell cycle transitions, promoting HCC progression and metastasis. Methods: The expression of KDM5B in normal li...Objective: To investigate the mechanism of cell cyclin-dependent kinase (KDM5B), a key enzyme driving all cell cycle transitions, promoting HCC progression and metastasis. Methods: The expression of KDM5B in normal liver, HCC and its adjacent tissues was analyzed by RT-PCR and IHC. Lentivirus transfection method was used to construct stable cell lines with KDM5B overexpression and down-regulation, and the role of KDM5B in HCC migration and invasion was detected at cell level and animal level. Western blotting and Transwell experiments were performed to verify the effect of KDM5B and/or CCR2 inhibitors on HCC progression and metastasis by using liver orthotopic transplantation tumor model and immunofluorescence methods. Results: RT-PCR showed that the expression level of KDM5B in HCC was significantly higher than that in adjacent tissues, and the increase of KDM5B was relatively significant. Upregulation of KDM5B in nude mouse liver orthotopic transplantation tumor model can promote the incidence of lung metastasis and shorten the survival time of nude mice, whereas upregulation of KDM5B can reduce the incidence of lung metastasis and prolong the survival time of nude mice. Conclusion: This study clarified the expression of KDM5B in HCC and its function in promoting HCC migration, invasion and metastasis. The molecular mechanism of KDM5B promoting HCC metastasis was revealed, providing a potential therapeutic target for HCC.展开更多
To determine the role of hepatitis B virus X protein (HBx), HBx in regulating hepatic progenitor cell (HPC)-like features in hepatocellular carcinoma (HCC) and the underlying molecular mechanisms.METHODSWe used a retr...To determine the role of hepatitis B virus X protein (HBx), HBx in regulating hepatic progenitor cell (HPC)-like features in hepatocellular carcinoma (HCC) and the underlying molecular mechanisms.METHODSWe used a retrovirus vector to introduce wild type HBx or empty vector into HepG2 cells. We then used these cells to analyze cell proliferation, senescence, transformation, and stem-like features. Gene expression profiling was carried out on Affymetrix GeneChip Human U133A2.0 ver.2 arrays according to the manufacturer’s protocol. Unsupervised hierarchical clustering analysis and Class Comparison analysis were performed by BRB-Array Tools software Version 4.2.2. A total of 238 hepatitis B virus (HBV)-related HCC patients’ array data were used for analyzing clinical features.RESULTSThe histone demethylase KDM5B was significantly highly expressed in HBV-related HCC cases (P < 0.01). In HBV proteins, only HBx up-regulated KDM5B by activating c-myc. Hepatic stem cell (HpSC) markers (EpCAM, AFP, PROM1, and NANOG) were significantly highly expressed in KDM5B-high HCC cases (P < 0.01). KDM5B played an important role in maintaining HpSC-like features and was associated with a poor prognosis. Moreover, inhibition of KDM5B suppressed spheroid formation and cell invasion in vitro.CONCLUSIONHBx activates the histone demethylase KDM5B and induces HPC-like features in HCC. Histone demethylases KDM5B may be an important therapeutic target against HBV-related HCC cases.展开更多
KDM5B is a histone H3K4me2/3 demethylase. The PHD1 domain of KDM5B is critical for demethylation, but the mechanism underlying the action of this domain is unclear. In this paper, we observed that PHDIKDMSB interacts ...KDM5B is a histone H3K4me2/3 demethylase. The PHD1 domain of KDM5B is critical for demethylation, but the mechanism underlying the action of this domain is unclear. In this paper, we observed that PHDIKDMSB interacts with unmethylated H3K4me0. Our NMR structure of PHDIKDMSB in complex with H3K4me0 revealed that the binding mode is slightly different from that of other reported PHD fingers. The disruption of this interaction by double mutations on the residues in the interface （L325A/D328A） decreases the H3K4me2/3 demethylation activity of KDM5B in cells by approximately 50% and increases the transcriptional repression of tumor suppressor genes by approximately twofold. These findings imply that PHDIKDMSB may help maintain KDM5B at target genes to mediate the demethylation activities of KDM5B.展开更多
文摘Objective: To investigate the mechanism of cell cyclin-dependent kinase (KDM5B), a key enzyme driving all cell cycle transitions, promoting HCC progression and metastasis. Methods: The expression of KDM5B in normal liver, HCC and its adjacent tissues was analyzed by RT-PCR and IHC. Lentivirus transfection method was used to construct stable cell lines with KDM5B overexpression and down-regulation, and the role of KDM5B in HCC migration and invasion was detected at cell level and animal level. Western blotting and Transwell experiments were performed to verify the effect of KDM5B and/or CCR2 inhibitors on HCC progression and metastasis by using liver orthotopic transplantation tumor model and immunofluorescence methods. Results: RT-PCR showed that the expression level of KDM5B in HCC was significantly higher than that in adjacent tissues, and the increase of KDM5B was relatively significant. Upregulation of KDM5B in nude mouse liver orthotopic transplantation tumor model can promote the incidence of lung metastasis and shorten the survival time of nude mice, whereas upregulation of KDM5B can reduce the incidence of lung metastasis and prolong the survival time of nude mice. Conclusion: This study clarified the expression of KDM5B in HCC and its function in promoting HCC migration, invasion and metastasis. The molecular mechanism of KDM5B promoting HCC metastasis was revealed, providing a potential therapeutic target for HCC.
基金supported by the National Natural Science Foundation of China(No.3146028631660307+7 种基金31260252)the Natural Science Foundation of Xizang(Tibet) Autonomous Region(No.2015ZR-13-192016ZR)Innovation program of University Young Teacher,Tibet Autonomous Region(QC2016-29)the Social Science Foundation of the Chinese Ministry of Education(No.12YJA850011)the School Foundation of Xizang Minzu University(No.11myY20)Xizang Minzu University graduate practice and innovation project in 2016(No.2016MDYJS001)
基金Supported by Grant-in-Aid for Scientific Research(KAKENHI)(C),No.15K08992(to Oishi N)Core-to-Core Program,B.Asia-Africa Science Platforms,the Japan Society for the Promotion of Science(to Kaneko S)
文摘To determine the role of hepatitis B virus X protein (HBx), HBx in regulating hepatic progenitor cell (HPC)-like features in hepatocellular carcinoma (HCC) and the underlying molecular mechanisms.METHODSWe used a retrovirus vector to introduce wild type HBx or empty vector into HepG2 cells. We then used these cells to analyze cell proliferation, senescence, transformation, and stem-like features. Gene expression profiling was carried out on Affymetrix GeneChip Human U133A2.0 ver.2 arrays according to the manufacturer’s protocol. Unsupervised hierarchical clustering analysis and Class Comparison analysis were performed by BRB-Array Tools software Version 4.2.2. A total of 238 hepatitis B virus (HBV)-related HCC patients’ array data were used for analyzing clinical features.RESULTSThe histone demethylase KDM5B was significantly highly expressed in HBV-related HCC cases (P < 0.01). In HBV proteins, only HBx up-regulated KDM5B by activating c-myc. Hepatic stem cell (HpSC) markers (EpCAM, AFP, PROM1, and NANOG) were significantly highly expressed in KDM5B-high HCC cases (P < 0.01). KDM5B played an important role in maintaining HpSC-like features and was associated with a poor prognosis. Moreover, inhibition of KDM5B suppressed spheroid formation and cell invasion in vitro.CONCLUSIONHBx activates the histone demethylase KDM5B and induces HPC-like features in HCC. Histone demethylases KDM5B may be an important therapeutic target against HBV-related HCC cases.
文摘KDM5B is a histone H3K4me2/3 demethylase. The PHD1 domain of KDM5B is critical for demethylation, but the mechanism underlying the action of this domain is unclear. In this paper, we observed that PHDIKDMSB interacts with unmethylated H3K4me0. Our NMR structure of PHDIKDMSB in complex with H3K4me0 revealed that the binding mode is slightly different from that of other reported PHD fingers. The disruption of this interaction by double mutations on the residues in the interface （L325A/D328A） decreases the H3K4me2/3 demethylation activity of KDM5B in cells by approximately 50% and increases the transcriptional repression of tumor suppressor genes by approximately twofold. These findings imply that PHDIKDMSB may help maintain KDM5B at target genes to mediate the demethylation activities of KDM5B.
