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A further understanding of the molecular mechanism of hepatocellular carcinoma (HCC) is necessary to predict a patient's prognosis and develop new targeted gene drugs. This study aims to identify essential genes related to HCC. We used the Weighted Gene Co-expression Network Analysis (WGCNA) and differential gene expression analysis to analyze the gene expression profile of GSE45114 in the Gene Expression Omnibus (GEO) database and The Cancer Genome Atlas database (TCGA). A total of 37 overlapping genes were extracted from four groups of results. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) enrichment analyses were performed on the 37 overlapping genes. Then, we used the STRING database to map the protein interaction (PPI) network of 37 overlapping genes. Ten hub genes were screened according to the Maximal Clique Centrality (MCC) score using the Cytohubba plugin of Cytoscape (including FOS, EGR1, EPHA2, DUSP1, IGFBP3, SOCS2, ID1, DUSP6, MT1G, and MT1H). Most hub genes show a significant association with immune infiltration types and tumor stemness of microenvironment in HCC. According to Univariate Cox regression analysis and Kaplan-Meier survival estimation, SOCS2 was positively correlated with overall survival (OS), and IGFBP3 was negatively correlated with OS. Moreover, the expression of IGFBP3 increased with the increase of the clinical stage, while the expression of SOCS2 decreased with the increase of the clinical stage. In conclusion, our findings suggest that SOCS2 and IGFBP3 may play an essential role in the development of HCC and may serve as a potential biomarker for future diagnosis and treatment. [ABSTRACT FROM AUTHOR]

3 Depletion of SNHG1 enhances the effects of sorafenib in promoting apoptosis and autophagy of sorafenib-resistant cells. " " (P < 0.05) and " " (P < 0.001) indicate a significant difference Reference 1 Li W, Dong X, He C. LncRNA SNHG1 contributes to sorafenib resistance by activating the Akt pathway and is positively regulated by miR-21 in hepatocellular carcinoma cells. [Extracted from the article]

Sorafenib displays a limited efficacy for advanced hepatocellular carcinoma ( HCC). Some patients with HCC initially respond to sorafenib, but eventually succumb to the disease, indicating that the acquired resistance to sorafenib reduces its beneficial effects. No alternative drugs are available after the failure of sorafenib therapy. Therefore, investigation of the mechanisms underlying the acquired resistance and development of second-line treatments for sorafenib-resistant HCC are urgently required. In this study, sorafenib-resistant HCC cells generated from sorafenib-sensitive human HCC cells were shown to overproduce hepatocyte growth factor ( HGF) and overexpress c-Met kinase and its phosphorylated form, leading to the activation of Akt and ERK (extracellular signaling-regulated kinase) pathways. Use of specific c-Met inhibitors enhanced the effects of sorafenib by inhibiting the growth of sorafenib-resistant HCC cells. Akt inhibitors, a class of second-line therapeutic drugs under investigation for treating HCC in clinical trials, enhanced the effects of sorafenib, but also activated the c-Met pathway in sorafenib-resistant cells. Dual inhibition of Akt and c-Met by their respective inhibitors, MK2206 and capmatinib, additively or synergistically suppressed sorafenib-resistant HCC cells in vitro and sorafenib-resistant HCC xenografts in mice. The anticancer activities of MK2206 mainly rely on its ability to induce cell apoptosis and autophagic death, while capmatinib treatment leads to cell cycle arrest at phase G1. These results provide strong evidence for further investigation on the clinical utility of dual inhibition of Akt and c-Met, particularly MK2206 and capmatinib, as a second-line therapy for advanced HCC that has acquired resistance to sorafenib. [ABSTRACT FROM AUTHOR]

In the original article, there was one misplaced image in Fig. 4a (the representative MDM2 blot in Hep3B cells). [ABSTRACT FROM AUTHOR]

Background: Cyclooxygenase (COX)-2 is overexpressed in many types of cancers including hepatocellular carcinoma (HCC). Meloxicam, a selective COX-2 inhibitor, has shown potential therapeutic effects against HCC, but the mechanisms accounting for its anti-cancer activities remain unclear. Methods and Findings: Meloxicam inhibited the ability of human HCC cells expressing higher levels of COX-2 to migrate, invade, adhere and form colonies through upregulating the expression of E-cadherin and downregulating the expression of matrix metalloproteinase (MMP) -2. Meloxicam induced cell apoptosis by upregulating pro-apoptotic proteins including Bax and Fas-L, and downregulating anti-apoptotic proteins including survivin and myeloid cell leukemia-1 (Mcl-1), through inhibiting phosphorylation of AKT. Addition of prostaglandin E2 (PGE2), the major product of COX-2, could abrogate the effects of meloxicam on the expression of survivin and myeloid cell leukemia-1 (Mcl-1), but not Bax and Fas-L, indicating that meloxicam induces cell apoptosis via both COX-2-dependent and -independent pathways. Meloxicam also induced cell autophagy by upregulating Beclin 1 and light chain 3-II. Specific inhibition of autophagy by 3-methyladenine and chloroquine had little effect on cell apoptosis but could enhance the pro-apoptotic effects of meloxicam by further upregulating the expression of Bax. Conclusions: Meloxicam executes its antitumor effects by targeting the COX-2/MMP-2/E-cadherin, AKT, apoptotic and autophagic pathways in COX-2-dependent and -independent pathways, and inhibition of cell autophagy could help to overcome the resistance to meloxicam-induced apoptosis in HCC. [ABSTRACT FROM AUTHOR]

Nutlin-3, a selective small-molecule inhibitor of the p53-MDM2 interaction, has been shown to have antitumor activities in various tumors with wild-type p53. However, its effect on hepatocellular carcinoma (HCC) with different types of p53 remains unclear. This study is designed to determine nutlin-3′s antitumor efficacy and underlying mechanisms of action in human HCC cells. Cell viability assay, cell cycle analysis, apoptosis assay, western blot, co- immunoprecipitation and siRNA experiments were analyzed in three human HCC cells. Anti-tumoral effects of nutlin-3 targeting the p53 and p73 pathways were evaluated in HCC cell lines. Nutlin-3 exerted the greatest anti-tumoral effect to three human HCC cells with wild-type p53, mutant p53 and p53-null. Nutlin-3 not only upregulated p53 in HepG2 cells, but also p73 in Huh7 and Hep3B cells, and disrupted p53-MDM2 and p73-MDM2 complexes in HCC cells. The compound inhibited cell proliferation, induced G0/G1 phase arrest, decreased the levels of CyclinD1, CyclinE, CDK2, CDK4, PCNA and E2F-1, and increased the levels of p21 and p27. It also induced apoptosis, increased the Bax/Bcl-2 ratio, then activated caspase-9 and caspase-3. Nutlin-3 has significant anticancer effects against human HCC cells, regardless of p53 status, indicating that it is a promising therapy for human hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

Background and Aims: Cyclooxygenase-2 (COX-2) is associated with carcinogenesis. The aim of this study was to investigate the expression of COX-2 in four hepatocellular carcinoma (HCC) cell lines, and evaluate the effect of a selective COX-2 inhibitor, meloxicam, in HepG2, a high COX-2 expressing cell line. Methods: Expression of COX-2 was detected using RT-PCR, Western blotting and immunohistochemical analysis. Cell proliferation was measured using MTT assay. Cell cycle distribution was determined by flow cytometry. Apoptosis was detected with TUNEL method. Expression of proliferating cell nuclear antigen (PCNA), cell cycle regulatory proteins including cyclins A, B1, D1 and E, and apoptosis-related proteins including Fas, Fas ligand and Bcl-2 were examined using Western blotting. Results: Cyclooxygenase-2 was intensely expressed in HepG2, HLE and BEL7402 cells, but weakly expressed in SMMC-7402 cells. Meloxicam suppressed proliferation of HepG2 cells in a dose- and time-dependent manner, resulting in cell cycle arrest in S phase and cell accumulation in G0/G1 phase. Expression of PCNA, cyclin A but not cyclin B1, cyclin D1 or cyclin E was down-regulated by meloxicam. Meloxicam also induced apoptosis of HepG2 cells, with increased expression of Fas ligand, but the expression of Fas and Bcl-2 was not affected by meloxicam treatment. Conclusions: The present study demonstrates that the specific COX-2 inhibitor meloxicam suppresses proliferation and induces apoptosis in HCC cells that express COX-2, suggesting that COX-2 inhibition may offer a novel chemopreventive and therapeutic approach for HCC. [ABSTRACT FROM AUTHOR]

Background: Arsenic trioxide has been demonstrated as an effective anti-cancer drug against leukemia and solid tumors both in vitro and in vivo. However, recent phase II trials demonstrated that single agent arsenic trioxide was poorly effective against hepatocellular carcinoma (HCC), which might be due to drug resistance. Methods: Mutation detection of p53 gene in arsenic trioxide resistant HCC cell lines was performed. The therapeutic effects of arsenic trioxide and Nutlin-3 on HCC were evaluated both in vitro and in vivo. A series of experiments including MTT, apoptosis assays, co-Immunoprecipitation, siRNA transfection, lentiviral infection, cell migration, invasion, and epithelial-mesenchy-mal transition (EMT) assays were performed to investigate the underlying mechanisms. Results: The acquisition of p53 mutation contributed to arsenic trioxide resistance and enhanced metastatic potential of HCC cells. Mutant p53 (Mutp53) silence could re-sensitize HCC resistant cells to arsenic trioxide and inhibit the metastatic activities, while mutp53 overexpression showed the opposite effects. Neither arsenic trioxide nor Nutlin-3 could exhibit obvious effects against arsenic trioxide resistant HCC cells, while combination of them showed significant effects. Nutlin-3 can not only increase the intracellular arsenicals through inhibition of p-gp but also promote the p73 activation and mutp53 degradation mediated by arsenic trioxide. In vivo experiments indicated that Nutlin-3 can potentiate the antitumor activities of arsenic trioxide in an orthotopic hepatic tumor model and inhibit the metastasis to lung. Conclusions: Acquisitions of p53 mutations contributed to the resistance of HCC to arsenic trioxide. Nutlin-3 could overcome arsenic trioxide resistance and inhibit tumor metastasis through p73 activation and promoting mutant p53 degradation mediated by arsenic trioxide.

Background: Gankyrin has shown to be overexpressed in human liver cancers and plays a complex role in hepatocarcinogenesis. Panobinostat (LBH589), a new hydroxamic acid-derived histone deacetylase inhibitor has shown promising anticancer effects recently. Here, we investigated the potential of LBH589 as a form of treatment for hepatocellular carcinoma (HCC). Methods: Gankyrin plasmid was transfected into HCC cells, and the cells were selected for more than 4 weeks by incubation with G418 for overexpression clones. The therapeutic effects of LBH589 were evaluated in vitro and in vivo. Cell proliferation, apoptosis, cell cycle, invasive potential, and epithelial-mesenchy-mal transition (EMT) were examined. Results: LBH589 significantly inhibited HCC growth and metastasis in vitro and in vivo. Western blotting analysis indicated that LBH589 could decrease the expression of gankyrin and subsequently reduced serine-phosphorylated Akt and tyrosine-phosphorylated STAT3 expression although the total Akt and STAT3 were unaffected. LBH589 inhibited metastasis in vitro via down-regulation of N-cadherin, vimentin, TWIST1, VEGF and up-regulation of E-cadherin. LBH589 also induced apoptosis and G1 phase arrest in HCC cell lines. Ectopic expression of gankyrin attenuated the effects of LBH589, which indicates that gankyrin might play an important role in LBH589 mediated anticancer effects. Lastly, in vivo study indicated that LBH589 inhibited tumor growth and metastasis, without discernable adverse effects comparing to control group, with abrogating gankyrin/STAT3/Akt pathway. Conclusions: Our results suggested that LBH589 could inhibit HCC growth and metastasis through down-regulating gankyrin/STAT3/Akt pathway. LBH589 may present itself as a novel therapeutic strategy for HCC.

Background & Aims: Hypoxia-inducible factors (HIFs) and nuclear factor-κB (NF-κB) regulate genes involved in carcinogenesis and progression of cancers including hepatocellular carcinoma (HCC). The von Hippel–Lindau (VHL) protein (pVHL) targets HIFα subunits for destruction and participates in modulating the activity of NF-κB. The present study aimed to investigate whether the overexpression of pVHL synergizes with doxorubicin in the treatment of HCC. Methods: Overexpression of pVHL was induced by infecting mouse HCC Hepa1–6 and H22 cells, or injecting subcutaneous Hepa1–6 tumors in C57BL/c mice, with adenoviral vectors encoding mouse VHL gene. Cell proliferation, apoptosis, tumoral angiogenesis, and gene expression and DNA-binding activity of NF-κB were examined. The therapeutic effects of pVHL were also evaluated in orthotopic Hepa1–6 tumors by intraportal delivery of Ad-VHL. Results: Ad-VHL enhanced the anti-tumor activity of doxorubicin by inhibiting cell proliferation, and causing cell cycle arrest and apoptosis. The Ad-VHL infection downregulated HIF-1α and HIF-2α expression, and inhibited NF-κB activity and the expression of genes involved in apoptosis, proliferation, angiogenesis, invasion, and metastasis. Injection of Ad-VHL into HCC tumors augmented doxorubicin-induced suppression of tumor growth by inhibiting cell proliferation and tumor angiogenesis, and by inducing cell apoptosis. Effects on the expression of HIFαs, activity of NF-κB, and their downstream genes were in accordance with the in vitro findings. Intraportal injection of Ad-VHL enhanced the efficacy of doxorubicin to suppress the growth of orthotopic liver tumors. Conclusions: By targeting HIF and NF-κB, overexpression of pVHL enhances the efficacy of doxorubicin, and warrants consideration as a potential therapeutic strategy for treating HCC. [Copyright &y& Elsevier]

Abstract: Hepatocellular carcinoma (HCC) is one of the most common malignancies and the third leading cause of cancer mortality world wide. Despite continuing development of new therapies, the prognosis for patients with HCC remains extremely poor. In part, this may relate to molecular abnormalities that stimulate HCC tumorigenesis and also contribute to reduced sensitivity to standard treatment. Increasing evidence has revealed the importance of liver cancer stem cells in hepatocarcinogenesis. Although widely investigated, the signaling pathways important for liver cancer stem cells in liver tumor initiation and progression are poorly understood. The Hippo signaling pathway was identified in Drosophila as an essential regulator of cell proliferation and apoptosis. Recently, Hippo pathway has been implicated in multiple events during development and it has also been proposed to play a vital role in several tumor types, especially in hepatocellular carcinoma. Strong evidences also proved the significant role of the Hippo signaling pathway in oval cell activation. As suggested, hippo signaling has a dual regulation of Hippo in liver tumor suppression as well as transition of oval cells to fully differentiated hepatocytes. Delineation of the malfunction of Hippo signaling pathway in HCC may lead to better understanding of hepatocarcinogenesis, rational medical therapy for HCC and possible therapy for other tumors. Here, we provide a historical review of this potent growth-regulatory pathway in HCC and highlight outstanding questions that will likely be the focus of future investigation. [Copyright &y& Elsevier]

Targeting energy metabolism holds the potential to effectively treat a variety of malignant diseases, and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) is a key regulator of energy metabolism. However, PGC1α′s role in cancer, especially in hepatocellular carcinoma (HCC) remains largely unknown. In the present study, we reported that PGC1α was significantly downregulated in HCC cell lines and specimens. Moreover, reduced expression of PGC1α in tumor cells was correlated with poor prognosis. PGC1α overexpression substantially inhibited cell proliferation and induced apoptosis in vitro and in vivo. On the contrary, the knockdown of PGC1α produced the opposite effect. The mechanism was at least partially due to the upregulation of mitochondrial pyruvate carrier 1 (MPC1) caused by PGC1α, which promoted mitochondrial biogenesis by binding to nuclear respiratory factor 1 (NRF1). Consequently, the production of cellular reactive oxygen species (ROS) caused by mitochondrial oxidation was elevated above a critical threshold for survival. Furthermore, we found that PGC1α could enhance the antitumor activity of sorafenib and doxorubicin in HCC through ROS accumulation-mediated cell death. These results indicate that PGC1α/NRF1-MPC1 axis is involved in HCC progression and could be a promising target for HCC treatment. Image 1 • Low expression of PGC1α and MPC1 was associated with the poor prognosis of HCC. • PGC1α and MPC1 could inhibit HCC cell proliferation and induce apoptosis. • PGC1α/NRF1-MPC1 axis activates mitochondrial biogenesis and drives ROS production. • PGC1α/NRF1-MPC1 axis attenuates HCC progression. • PGC1α could enhance the sensitivity to sorafenib/doxorubicin treatment in HCC. [ABSTRACT FROM AUTHOR]

Abstract: The present study aimed to investigate the anti-cancer effects of hydroxytyrosol (HT) in human hepatocellular carcinoma (HCC) cells. Our results show that HT could inhibit proliferation, induce G2/M cell cycle arrest and apoptosis in human HCC cells. Mechanically, we found that HT could suppress the activation of AKT and nuclear factor-kappa B (NF-κB) pathways. HT also significantly inhibited the tumor growth, angiogenesis and the activation of AKT and NF-κB pathways in an orthotopic model of human HCC in vivo. These data suggest that HT may be a promising candidate agent for the treatment of HCC. [Copyright &y& Elsevier]

Abstract: Sorafenib, the first-line systemic drug for advanced hepatocellular carcinoma (HCC), has demonstrated limited benefits with very low response rates. Thus it is essential to investigate the underlying mechanisms for the resistance to sorafenib and seek potential strategy to enhance its efficacy. Hypoxic cells inside solid tumors are extremely resistant to therapies as their survival ability is increased due to the cellular adaptive response to hypoxia, which is controlled by hypoxia-inducible factor (HIF)-1 and HIF-2. Sorafenib inhibits HIF-1α synthesis, making the hypoxic response switch from HIF-1α- to HIF-2α-dependent pathways and providing a mechanism for more aggressive growth of tumors. The present study has demonstrated that upregulation of HIF-2α induced by sorafenib contributes to the resistance of hypoxic HCC cells by activating the transforming growth factor (TGF)-α/epidermal growth factor receptor (EGFR) pathway. Blocking the TGF-α/EGFR pathway by gefitinib, a specific EGFR inhibitor, reduced the activation of STAT (signal transducer and activator of transcription) 3, AKT and ERK (extracellular signal-regulated kinase), and synergized with sorafenib to inhibit proliferation and induce apoptosis of hypoxic HCC cells. Transfection of HIF-2α siRNA into HCC cells downregulated the expression of VEGF (vascular endothelial growth factor), cyclin D1, HIF-2α and TGF-α, and inhibited the activation of EGFR. HIF-2α siRNA inhibited the proliferation and promoted the apoptosis of HCC cells in vitro, and synergized with sorafenib to suppress the growth of HCC tumors in vivo. The results indicate that targeting HIF-2α-mediated activation of the TGF-α/EGFR pathway warrants further investigation as a potential strategy to enhance the efficacy of sorafenib for treating HCC. [Copyright &y& Elsevier]

Abstract: Hepatocellular carcinoma (HCC) is a highly lethal malignancy mostly because of de novo and acquired resistance to conventional chemotherapy. Constitutive activation of Akt and nuclear factor-κB (NF-κB) represent major cellular abnormalities associated with both the pathogenesis and therapeutic resistance of HCC. The aim of the present study was to determine whether genistein, a natural Akt/NF-κB inhibitor, could enhance the anti-HCC efficacy of ATO both in vitro and in vivo. Our results demonstrated that genistein not only potentiated the proliferation-inhibiting and apoptosis-inducing effect of ATO on human HCC cell lines in vitro, but also dramatically augmented its suppressive effect on both tumor growth and angiogenesis in nude mice. The mechanism is at least partially due to the suppressive effect of genistein both on the proper and ATO-induced Akt activation, and on the activity of NF-κB, and the latter correlated with the suppression of NF-κB regulated gene products, including cyclin D1, Bcl-xL, Bcl-2, c-myc, COX-2, and VEGF. These data suggest that the combination of ATO with genistein presents a promising therapeutic approach for the treatment of HCC. [ABSTRACT FROM AUTHOR]

Abstract: Background/Aims: B7H3 immunogene therapy is able to completely eradicate tumors when combined with an anti-vascular agent. The aim of this study was to determine whether vasostatin, a potent anti-angiogenic agent, could synergize with B7H3-mediated immunotherapy to combat hepatocellular carcinoma (HCC). Methods: Vasostatin and B7H3 expression plasmids were constructed, and the in vitro and in vivo expression and anti-angiogenic activity of recombinant vasostatin were measured. The anti-tumor activities of B7H3 and vasostatin alone and in combination were assessed using single and multiple H22 tumor models. Results: Gene transfer of vasostatin inhibited the proliferation of aortic endothelial cells, and angiogenesis in the chorioallantoic membrane assay. Subcutaneous H22 tumors established in BALB/c mice were completely eradicated in response to intratumoral injection of B7H3-expressing plasmids followed 24h later by vasostatin-expressing plasmids. In contrast, neither vasostatin nor B7H3 monotherapy was effective. Gene transfer of vasostatin inhibited tumor angiogenesis and enhanced infiltration of NK cells, whereas B7H3 therapy activated CD8+ and NK cells and increased their infiltration into tumors, and enhanced the levels of circulating IFN-γ. B7H3 and vasostatin combination gene therapy was effective in combating a systemic challenge of parental H22 cells, and caused the complete regression of multiple distant tumor nodules. Conclusions: Combining vasostatin anti-angiogenic therapy with B7H3-mediated immunotherapy warrants investigation as a therapeutic strategy to combat HCC, and other malignancies. [Copyright &y& Elsevier]