Novel molecular therapies in hepatocellular carcinoma

The combination of Biochanin A and SB590885 potentiates the inhibition of tumour progression in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the most aggressive and frequently diagnosed malignancy of the liver. Despite aggressive therapy, life expectancy of many patients in these cases is extended by only a few months. Hepatocellular carcinoma (HCC) has a particularly poor prognosis and would greatly benefit from more effective therapies.

Methods

The CCK-8 assay and colony formation assays were used to test the cell proliferation and viability. The effects of combination Biochanin A and SB590885 on apoptosis and cell cycle arrest of HCC cells were analysed by flow cytometry. The expression of ERK MAPK and PI3K/AKT/mTOR signalling as well as apoptosis and cell cycle-related proteins in HCC cells were tested by western blotting. The HCC cell xenograft model was established to test the tumor proliferation. Serum and plasma were tested for liver and kidney safety markers (ALP, ALT, AST, total bilirubin, creatinine, urea nitrogen) by using SpectraMax i3X.

Results

The combination of natural product Biochanin A with the BRAF inhibitor SB590885 synergistically suppressed proliferation, and promoted cell cycle arrest and apoptosis in vitro. Furthermore, we demonstrated that the combination of Biochanin A and SB590885 led to increased impairment of proliferation and HCC tumour inhibition through disrupting of the ERK MAPK and the PI3K/AKT pathways in vitro. The volumes tumors and the weights of tumours were significantly reduced by the combination treatment compared to the control or single treatments in vivo. In addition, we found that there was no significant hepatorenal toxicity with the drug combination, as indicated by the hepatorenal toxicity test.

Conclusion

The results identify an effective combination therapy for the most aggressive form of HCC and provide the possibility of therapeutic improvement for patients with advanced HCC.

Preclinical efficacy of a novel dual PI3K/mTOR inhibitor, CMG002, alone and in combination with sorafenib in hepatocellular carcinoma

PURPOSE

Sorafenib has been the only first systemic drug that improves survival of patients with advanced hepatocellular carcinoma (HCC). However, because the response rate of sorafenib is relatively low, novel therapeutic strategies are needed to improve survival in patients with HCC. This study investigated the effect of CMG002 alone and in combination with sorafenib on HCC in vitro and vivo.

METHODS

The effect of a newly developed dual PI3K/mTOR inhibitor, CMG002, on the proliferation of Huh-7 and HepG2 HCC cells was investigated using the MTT assay. Western blotting was performed to assess phosphorylation of the key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways. HepG2 cells were inoculated into mice, which were treated with vehicle, sorafenib, CMG002, and their combinations. Tumor cell proliferation and tumor angiogenesis were evaluated by immunohistochemical analysis of Ki-67 and CD31, respectively. Tumor cell apoptosis was detected by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Levels of key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways were evaluated by western blot analysis.

RESULTS

The combination of sorafenib and CMG002 additively inhibited Huh-7 and HepG2 cell proliferation compared to single-agent treatment. Sorafenib and CMG002 as single agents differentially inhibited or activated key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways. The combination of sorafenib and CMG002 inhibited all key enzymes in the two pathways. Treatment with CMG002 for 4 weeks alone and in combination with sorafenib strongly inhibited tumor growth. CMG002 inhibited HCC cell proliferation, induced apoptosis, and decreased tumor angiogenesis. Furthermore, these effects were enhanced when CMG002 was combined with sorafenib.

CONCLUSIONS

The combination of CMG002 and sorafenib significantly inhibited HCC cell proliferation and tumorigenesis by inhibiting the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways. These findings suggest that CMG002 to be a potential novel candidate treatment for HCC.

Upregulation of FoxP4 in HCC promotes migration and invasion through regulation of EMT

Previous studies have indicated that FoxP1, FoxP2 and FoxP3 play important roles in hepatocellular carcinoma (HCC). However, the effect of FoxP4 in HCC requires further elucidation. The aim of the present study was to explore the roles of FoxP4 in HCC and further decipher the detailed mechanism. In present study, it was found that FoxP4, which is overexpressed in HCC tissues and cell lines, facilitated EMT in HCC cell lines through regulation of Slug. First, increased expression of FoxP4 was identified in 110 pairs of human HCC tumor and their adjacent normal tissues. In addition, the association between FoxP4 expression and clinicopathological features of HCC patients indicated that FoxP4 played vital roles in HCC development. Subsequently, gain- and loss-of-function experiments indicated that FoxP4 promoted cellular proliferation, migration as well invasion. In addition, EMT, a key mechanism during cancer metastasis, was regulated by FoxP4. Furthermore, ChIP and qChIP as well as luciferase reporter assays indicated that Slug, an EMT-associated transcription factor, was transcriptionally regulated by FoxP4. In conclusion, FoxP4 functioned as a tumor promoter in HCC cells by transcriptionally regulating Slug, and the present study highlighted the potential effects of FoxP4 on the prognosis and treatment of HCC.

A Computational Approach to Identify Novel Potential Precursor miRNAs and their Targets from Hepatocellular Carcinoma Cells

Background:

Recent advances in next-generation sequencing technology allow highthroughput RNA-Sequencing to be widely applied in studying coding and non-coding RNA profiling in cells. RNA-Seq data usually contains functional transcriptomic and other small and larger non-coding (nc) RNA sequences. </P><P> Objective: MicroRNAs (miRNAs), a small nc-RNA act as epigenetic markers and the expression of their target genes and pathways that regulate Hepatocellular Carcinoma (HCC), a primary malignancy of the liver. The unreported potential novel miRNAs targeting HCC pathways can be identified from the sequenced data.

Methods:

In this study, we performed a computational identification of novel putative miRNAs and their targets from publicly available high-throughput sequencing Fastq data of human HCC cells HepG2, NorHep and SKHep1, retrieved from NCBI-SRA.

Results:

Totally, 572 unique known precursor miRNAs and 1062 unique novel miRNAs were identified from HepG2, Nor and SKHep1 HCC cell lines. Interestingly, 140 novel miRNAs were predicted to be extensively involved in targeting genes of HCC related pathways such as apoptosis, cell signaling, cell division, cell-cycle arrest, GPCR, MAPK cascade, TOR signaling, TNFSF11 signaling and liver development.

Conclusion:

The predicted novel miRNAs reported in the paper might have a vital role in regulating the molecular mechanism of HCC and thus, further studies on these miRNAs will provide significant clues for researchers into the complex biological process of liver cancer.

Inhibition of insulin-like growth factor 1 receptor enhances the efficacy of sorafenib in inhibiting hepatocellular carcinoma cell growth and survival

Hepatocellular carcinoma (HCC) is the fifth most common primary cancer and second largest cause of cancer-related death worldwide. The first-line oral chemotherapeutic agent sorafenib only increases survival in patients with advanced HCC by less than 3 months. Most patients with advanced HCC have shown limited response rates and survival benefits with sorafenib. Although sorafenib is an inhibitor of multiple kinases, including serine/threonine-protein kinase c-Raf, serine/threonine-protein kinase B-Raf, vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, VEGFR-3, and platelet-derived growth factor receptor β, HCC cells are able to escape from sorafenib treatment using other pathways that the drug insufficiently inhibits. The aim of this study was to identify and target survival and proliferation pathways that enable HCC to escape the antitumor activity of sorafenib. We found that insulin-like growth factor 1 receptor (IGF1R) remains activated in HCC cells treated with sorafenib. Knockdown of IGF1R sensitizes HCC cells to sorafenib treatment and decreases protein kinase B (AKT) activation. Overexpression of constitutively activated AKT reverses the effect of knockdown of IGF1R in sensitizing HCC cells to treatment with sorafenib. Further, we found that ceritinib, a drug approved by the U.S. Food and Drug Administration for treatment of non-small cell lung cancer, effectively inhibits the IGF1R/AKT pathway and enhances the inhibitory efficacy of sorafenib in human HCC cell growth and survival in vitro, in a xenograft mouse model and in the c-Met/β-catenin-driven HCC mouse model. Conclusion: Our study provides a biochemical basis for evaluation of a new combination treatment that includes IGF1R inhibitors, such as ceritinib and sorafenib, in patients with HCC. (Hepatology Communications 2018;2:732-746).

Exogenous hydrogen sulfide promotes hepatocellular carcinoma cell growth by activating the STAT3-COX-2 signaling pathway

The effects of hydrogen sulfide (H₂S) on cancer are controversial. Our group previously demonstrated that exogenous H₂S promotes the development of cancer via amplifying the activation of the nuclear factor-κB signaling pathway in hepatocellular carcinoma (HCC) cells (PLC/PRF/5). The present study aimed to further investigate the hypothesis that exogenous H₂S promotes PLC/PRF/5 cell proliferation and migration, and inhibits apoptosis by activating the signal transducer and activator of transcription 3 (STAT3)-cyclooxygenase-2 (COX-2) signaling pathway. PLC/PRF/5 cells were treated with 500 µmol/l NaHS (a donor of H₂S) for 24 h. The expression levels of phosphorylated (p)-STAT3, STAT3, cleaved caspase-3 and COX-2 were measured by western blot assay. Cell viability was detected by Cell Counting kit-8 assay. Apoptotic cells were observed by Hoechst 33258 staining. The expression of STAT3 and COX-2 messenger RNA (mRNA) was detected by semiquantitative reverse transcription-polymerase chain reaction. The production of vascular endothelial growth factor (VEGF) was evaluated by ELISA. The results indicated that treatment of PLC/PRF/5 cells with 500 µmol/l NaHS for 24 h markedly increased the expression levels of p-STAT3 and STAT3 mRNA, leading to COX-2 and COX-2 mRNA overexpression, VEGF induction, decreased cleaved caspase-3 production, increased cell viability and migration, and decreased number of apoptotic cells. However, co-treatment of PLC/PRF/5 cells with 500 µmol/l NaHS and 30 µmol/l AG490 (an inhibitor of STAT3) or 20 µmol/l NS-398 (an inhibitor of COX-2) for 24 h significantly reverted the effects induced by NaHS. Furthermore, co-treatment of PLC/PRF/5 cells with 500 µmol/l NaHS and 30 µmol/l AG490 markedly decreased the NaHS-induced increase in the expression level of COX-2. By contrast, co-treatment of PLC/PRF/5 cells with 500 µmol/l NaHS and 20 µmol/l NS-398 inhibited the NaHS-induced increase in the expression level of p-STAT3. In conclusion, the findings of the present study provide evidence that the STAT3-COX-2 signaling pathway is involved in NaHS-induced cell proliferation, migration, angiogenesis and anti-apoptosis in PLC/PRF/5 cells, and suggest that the positive feedback between STAT3 and COX-2 may serve a crucial role in hepatocellular carcinoma carcinogenesis.

The Abnormal Expression of MicroRNA-542-3p in Hepatocellular Carcinoma and Its Clinical Significance

Aim

To evaluate the expression of miRNA-542-3p in hepatocellular carcinoma, establish its function, and evaluate whether it could serve as a biomarker for diagnosis and prognosis of HCC patients.

Methods

qRT-PCR analysis was performed to determine the expression level of miRNA-542-3p in normal liver cells and HCC cell lines. Additionally, samples from TCGA consortium and from our patients were analyzed using biostatistical methods to ascertain whether miR-542-3p could be a good biomarker for HCC diagnosis and prognosis. The effects of miRNA-542-3p on HCC were investigated in HCCLM9 cells.

Results

The expression of miRNA-542-3p in HCC cells was significantly downregulated compared with normal liver cells. A lower level of expression of miRNA-542-3p was found in HCC tissue samples than in adjacent normal liver tissue samples from TCGA cases and our patients. Further evaluation revealed that the downregulation was clearly related to aggressive clinicopathological characteristics and affected the prognosis, as low-expressing patients tended to have shorter overall survival. Moreover, cell assays revealed that miR-542-3p overexpression inhibited HCC cell growth and induced apoptosis.

Conclusion

We demonstrated for the first time that miRNA-542-3p appears to function as a novel tumor suppressor in HCC and may serve as a promising prognostic biomarker in HCC patients.

SIRT5 promotes cell proliferation and invasion in hepatocellular carcinoma by targeting E2F1

Sirtuin 5 (SIRT5) is a member of the NAD+‑dependent class III protein deacetylases. Although it is known that SIRT5 deacetylates and activates urate oxidase in the liver mitochondria of mice, the mechanism of SIRT5 in the proliferation of hepatocellular carcinoma (HCC) remains to be fully elucidated. The present study investigated the expression and functional significance of SIRT5 in HCC, and examined the relevant mechanism. SIRT5 was found to be upregulated in HCC tissues and cell lines, and the higher expression of SIRT5 indicated poorer overall survival. Reverse transcription‑quantitative polymerase chain reaction analysis, western blot analysis, chromatin immunoprecipitation analysis, and luciferase reporter gene, proliferation and Transwell assays were performed to elucidate the function of SIRT5 in the regulation of cell proliferation and invasion in human HCC. Functionally, it was observed that the inhibition of SIRT5 significantly suppressed HCC cell proliferation and invasion, whereas the overexpression of SIRT5 promoted HCC cell proliferation and invasion in vitro. E2F transcription factor 1 (E2F1) was identified as a novel target gene of SIRT5. In addition, the knockdown of SIRT5 induced the expression of E2F1, and the knockdown of E2F1 in HCC cells partially reversed the effect of SIRT5 in promoting cell proliferation and invasion. Collectively, these data provide the first evidence, to the best of our knowledge, that the SIRT5 gene has an important regulatory role in liver carcinogenesis, and may function as a novel potential therapeutic target for HCC.

The antitumor activity of a lactosaminated albumin conjugate of doxorubicin in a chemically induced hepatocellular carcinoma rat model compared to sorafenib

BACKGROUND

Worldwide, consistent survival benefit for chemotherapy in hepatocellular carcinoma (HCC) is a golden goal for concerned researchers. Nexavar^® (sorafenib) is the only approved agent that achieved touchable successes in this regard. Thus, there is a pressing medical need for new promising drugs to improve HCC therapy.

AIMS

our designed lactosaminated albumin conjugate of doxorubicin (L-HSA-DOXO) that rapidly and preferentially accumulates in the liver is compared, for the first time at its MTD, with doxorubicin and sorafenib, not only for antitumor efficacy but also for overall survival.

METHODS

HCC was induced in male Wistar rats with N-nitrosodiethylamine added to drinking water (100mg/L) for 8 weeks. Endpoints were antitumor efficacy, tolerability and overall survival.

RESULTS

L-HSA-DOXO proved to be superior at least over doxorubicin in the majority of assessed endpoints. Circulating AFP-L3% was diminished in L-HSA-DOXO (14.5%) and sorafenib (18.4%) groups compared to DENA (31.1%) and doxorubicin (29.5%) groups. This superiority was further confirmed by Western blot analyses of some novel HCC biomarkers. Survival study reinforced consistent benefits of both L-HSA-DOXO and sorafenib.

CONCLUSIONS

L-HSA-DOXO shows at least comparable activity to sorafenib which clinically achieves only ∼3 months overall survival benefit. Combination of these two agents could act beneficially or synergistically via two different modes of action to fight HCC.

Downregulation of FOXP1 Inhibits Cell Proliferation in Hepatocellular Carcinoma by Inducing G1/S Phase Cell Cycle Arrest

Forkhead box P1 (FOXP1) belongs to a family of winged-helix transcription factors that are involved in the processes of cellular proliferation, differentiation, metabolism, and longevity. FOXP1 can affect cell proliferation and migratory ability in hepatocellular carcinoma (HCC) in vitro. However, little is known about the mechanism of FOXP1 in the proliferation of HCC cells. This study aimed to further explore the function of FOXP1 on the proliferation of HCC cells as well as the relevant mechanism involved. Western blot analysis, tumor xenograft models, and flow cytometry analysis were performed to elucidate the function of FOXP1 in the regulation of cell proliferation in human HCC. We observed that silencing FOXP1 significantly suppressed the growth ability of HCC cells both in vitro and in vivo. In addition, knockdown of FOXP1 induced G1/S phase arrest, and the expression of total and phosphorylated Rb (active type) as well as the levels of E2F1 were markedly decreased at 24 h; however, other proteins, including cyclin-dependent kinase (CDK) 4 and 6 and cyclin D1 did not show noticeable changes. In conclusion, downregulation of FOXP1 inhibits cell proliferation in hepatocellular carcinoma by inducing G1/S phase cell cycle arrest, and the decrease in phosphorylated Rb is the main contributor to this G1/S phase arrest.

Single Agent and Synergistic Activity of the "First-in-Class" Dual PI3K/BRD4 Inhibitor SF1126 with Sorafenib in Hepatocellular Carcinoma

Deregulated PI3K/AKT/mTOR, Ras/Raf/MAPK, and c-Myc signaling pathways are of prognostic significance in hepatocellular carcinoma (HCC). Sorafenib, the only drug clinically approved for patients with advanced HCC, blocks the Ras/Raf/MAPK pathway but it does not inhibit the PI3K/AKT/mTOR pathway or c-Myc activation. Hence, there is an unmet medical need to identify potent PI3K/BRD4 inhibitors, which can be used either alone or in combination with sorafenib to treat patients with advanced HCC. Herein, we show that SF1126 (pan PI3K/BRD4 inhibitor) as single agent or in combination with sorafenib inhibited proliferation, cell cycle, apoptosis, and multiple key enzymes in PI3K/AKT/mTOR and Ras/Raf/MAPK pathway in Hep3B, HepG2, SK-Hep1, and Huh7 HCC cell lines. We demonstrate that the active moiety of the SF1126 prodrug LY294002 binds to and blocks BRD4 interaction with the acetylated histone-H4 chromatin mark protein and displaced BRD4 coactivator protein from the transcriptional start site of MYC in Huh7 and SK-Hep1 HCC cell lines. Moreover, SF1126 blocked expression levels of c-Myc in HCC cells. Treatment of SF1126 either alone or in combination with sorafenib showed significant antitumor activity in vivo Our results establish that SF1126 is a dual PI3K/BRD4 inhibitor. This agent has completed a phase I clinical trial in humans with good safety profile. Our data support the potential future consideration of a phase II clinical trial of SF1126, a clinically relevant dual "first-in-class" PI3K/BRD4 inhibitor in advanced HCC, and a potential combination with sorafenib. Mol Cancer Ther; 15(11); 2553-62. ©2016 AACR.

Mechanism of apoptosis induction in human hepatocellular carcinoma cells following treatment with a gecko peptides mixture

The aim of the present study was to investigate the apoptotic effect and molecular mechanisms of gecko peptides mixture (GPM) on the human liver carcinoma HepG2 cell line in vitro. The methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay was performed to identify the dose- (0.10, 0.15, 0.20, 0.25 and 0.30 mg/ml) and time-dependent (24, 48 and 72 h) inhibitory effect of GPM on HepG2 cells and their proliferation. Hoechst 33258 staining was carried out to detect the nuclear change coupled with apoptosis induced by GPM. Western blotting was used to evaluate apoptosis-related protein expression changes induced by GPM, including caspase, cytochrome c (Cyt c) and apoptosis-inducing factor (AIF). MTT results showed that GPM significantly inhibited the proliferation of HepG2 cells in a dose- and time-dependent manner. Hoechst 33258 staining demonstrated that GPM induced typical apoptotic morphological changes, while western blotting analysis revealed that GPM increased caspase-3, caspase-9, Cyt c and AIF protein expression levels in HepG2 cells treated with 0.06 or 0.08 mg/ml for 24 h. In conclusion, GPM could induce apoptosis by activating the intrinsic mitochondrial apoptotic pathways.

Functional imaging of hepatocellular carcinoma

Imaging plays a key role in the clinical management of hepatocellular carcinoma (HCC), but conventional imaging techniques have limited sensitivity in visualizing small tumors and assessing response to locoregional treatments and sorafenib. Functional imaging techniques allow visualization of organ and tumor physiology. Assessment of functional characteristics of tissue, such as metabolism, proliferation and stiffness, may overcome some of the limitations of structural imaging. In particular, novel molecular imaging agents offer a potential tool for early diagnosis of HCC, and radiomics may aid in response assessment and generate prognostic models. Further prospective research is warranted to evaluate emerging techniques and their cost-effectiveness in the context of HCC in order to improve detection and response assessment.

Safety and Pharmacokinetics of Lenvatinib in Patients with Advanced Hepatocellular Carcinoma

PURPOSE

To determine the maximum tolerable dose (MTD), safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of lenvatinib in patients with advanced hepatocellular carcinoma (HCC).

EXPERIMENTAL DESIGN

This multicenter, open-label, phase I, dose-escalation study included patients aged 20 to 80 years, refractory to standard therapy, and stratified by hepatic function measured using Child-Pugh (CP) scores: CP-A (score, 5-6) and CP-B (score, 7-8). Lenvatinib was administered continually once daily for 4-week cycles. MTD was defined as the maximum dose associated with ≤ 1 dose-limiting toxicity (DLT) occurring in cycle 1 among 6 patients.

RESULTS

In total, 20 patients (9 in CP-A and 11 in CP-B) were enrolled. The MTD was 12 and 8 mg once daily in CP-A and CP-B, respectively; DLTs included proteinuria, hepatic encephalopathy, and hyperbilirubinemia. The most common grade 3 toxicities included hypertension in CP-A and hyperbilirubinemia in CP-B. Lenvatinib plasma concentration at 24 hours after administration (C24 h) for 12 mg once daily was higher in patients with HCC than in patients with other solid tumors shown in a previous phase I study, but C24 h for 25 mg once daily lenvatinib was comparable. After lenvatinib treatment, the number of circulating endothelial and c-Kit(+) cells decreased and the levels of interleukin (IL)-6, IL10, granulocyte-colony stimulating factor, and vascular endothelial growth factor increased (P < 0.05). Partial responses were observed in 3 patients and tumor shrinkage occurred in 14 patients.

CONCLUSIONS

Lenvatinib (12 mg once daily) demonstrated preliminary efficacy with manageable toxicity and is the recommended dose for phase II studies in patients with HCC and CP-A.

Evaluation of antiangiogenic efficacy in advanced hepatocellular carcinoma: Biomarkers and functional imaging

Many years after therapeutic wilderness, sorafenib finally showed a clinical benefit in patients with advanced hepatocellular carcinoma. After the primary general enthusiasm worldwide, some disappointments emerged particularly since no new treatment could exceed or at least match sorafenib in this setting. Without these new drugs, research focused on optimizing care of patients treated with sorafenib. One challenging research approach deals with identifying prognostic and predictive biomarkers of sorafenib in this population. The task still seems difficult; however appropriate investigations could resolve this dilemma, as observed for some malignancies where other drugs were used.

Silencing of NUF2 inhibits tumor growth and induces apoptosis in human hepatocellular carcinomas

BACKGROUND

As an important component of the NDC80 kinetochore complex, NUF2 is essential for kinetochore-microtubule attachment and chromosome segregation. Previous studies also suggested its involvement in development of various kinds of human cancers, however, its expression and functions in human hepatocellular carcinoma (HCC) are still unclear.

MATERIALS AND METHODS

In the present study, we aimed to test the hypothesis that NUF2 is aberrant in human HCCs and associated with cell growth.

RESULTS

Our results showed significantly elevated expression of NUF2 in human HCC tissues compared to adjacent normal tissues, and high expression of NUF2 in HCC cell lines. Using lentivirus-mediated silencing of NUF2 in HepG2 human HCC cells, we found that NUF2 depletion markedly suppressed proliferation and colony formation capacity in vitro, and dramatically hampered tumor growth of xenografts in vivo. Moreover, NUF2 silencing could induce cell cycle arrest and trigger cell apoptosis. Additionally, altered levels of cell cycle and apoptosis related proteins including cyclin B1, Cdc25A, Cdc2, Bad and Bax were also observed.

CONCLUSIONS

In conclusion, these results demonstrate that NUF2 plays a critical role in the regulation of HCC cell proliferation and apoptosis, indicating that NUF2 may serve as a potential molecular target for therapeutic approaches.

Differences in antiproliferative effect of STAT3 inhibition in HCC cells with versus without HBV expression

Chronic infection with hepatitis B virus (HBV) plays an important role in the etiology of hepatocellular carcinoma (HCC). Signal transducer and activator of transcription 3 (STAT3) inactivation could inhibit the tumor growth of HCC. In this study, differential antiproliferative effect of STAT3 inhibition was observed with HBV-related HCC cells being more resistant than non-HBV-related HCC cells. Resistance of HBV-related HCC cells to STAT3 inhibition was positively correlated to the expression of HBV. Enhanced ERK activation after STAT3 blockade was detected in HBV-related HCC cells but not in non-HBV-related HCC cells. Combined ERK and STAT3 inhibition eliminates the discrepancy between the two types of HCC cells. Moderate reduced HBV expression was found after STAT3 inhibition. These findings disclose a discrepancy in cellular response to STAT3 inhibition between non-HBV-related and HBV-related HCC cells and underscore the complexity of antiproliferative effect of STAT3 inactivation in HBV-related HCC cells.

The association of common functional polymorphisms in mir-146a and mir-196a2 and hepatocellular carcinoma risk: evidence from a meta-analysis

MicroRNAs (miRNAs) are small non-coding RNA molecules that function as tumor suppressors or oncogenes. Single nucleotide polymorphisms (SNPs) located in the miRNAs influence the function of mature miRNAs and may contribute to cancer development. Studies investigating the association between miR-146a rs2910164 and miR-196a2 rs11614913 polymorphisms and hepatocellular carcinoma (HCC) risk reported inconsistent results. We performed a meta-analysis of all available studies to summarize this situation. Eligible studies were identified by search of electronic databases including PubMed, Embase, and Cochrane library for the period up to August 2014. The association of miR-146a rs2910164 and miR-196a2 rs11614913 polymorphisms and HCC risk was assessed by odds ratios (ORs) together with their 95% confidence intervals (CIs). Finally, a total of 12 studies with 4171 cases and 4901 controls were included for miR-146a rs2910164 polymorphism and 10 studies with 4687 cases and 4990 controls were available for miR-196a2 rs11614913 polymorphism. With respect to miR-146a rs2910164 polymorphism, statistical significant increased HCC risk was found when all studies were pooled into the meta-analysis (GG+CG vs CC: OR = 1.097, 95% CI 1.005-1.197, P = 0.037). In subgroup analyses by ethnicity, source of control, and HWE in controls, significant increase of HCC risk was found in Asians, population-based studies, and studies consistent with HWE, but not in Caucasians, hospital-based studies, and studies inconsistent with HWE. With respect to miR-196a2 rs11614913 polymorphism, no significant association with HCC risk was found in the overall and subgroup analyses. The results suggest that the miR-146a rs2910164 polymorphism contributes to increased HCC susceptibility, especially in Asian populations. Further large and well-designed studies are required to validate this association.

Targeting the insulin-like growth factor pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Only 30%-40% of the patients with HCC are eligible for curative treatments, which include surgical resection as the first option, liver transplantation and percutaneous ablation. Unfortunately, there is a high frequency of tumor recurrence after surgical resection and most HCC seem resistant to conventional chemotherapy and radiotherapy. Sorafenib, a multi-tyrosine kinase inhibitor, is the only chemotherapeutic option for patients with advanced hepatocellular carcinoma. Patients treated with Sorafenib have a significant increase in overall survival of about three months. Therefore, there is an urgent need to develop alternative treatments. Due to its role in cell growth and development, the insulin-like growth factor system is commonly deregulated in many cancers. Indeed, the insulin-like growth factor (IGF) axis has recently emerged as a potential target for hepatocellular carcinoma treatment. To this aim, several inhibitors of the pathway have been developed such as monoclonal antibodies, small molecules, antisense oligonucleotides or small interfering RNAs. However recent studies suggest that, unlike most tumors, HCC development requires increased signaling through insulin growth factor II rather than insulin growth factor I. This may have great implications in the future treatment of HCC. This review summarizes the role of the IGF axis in liver carcinogenesis and the current status of the strategies designed to target the IGF-I signaling pathway for hepatocellular carcinoma treatment.

MicroRNAs in liver cancer: a model for investigating pathogenesis and novel therapeutic approaches

MicroRNAs (miRNAs) constitute a large class of short RNAs (e.g., 20-24 nucleotides in length), whose main function is to posttranscriptionally regulate the expression of protein-coding genes. Their importance in tumorigenesis has been demonstrated over the past decade, and correspondingly, they have emerged as potential therapeutic molecules and targets. Liver cancer is one of the most common neoplastic diseases worldwide, and it currently has a poor prognosis owing to largely ineffective therapeutic options. Liver cancer is also an excellent model for testing miRNA-based therapy approaches as it can be easily targeted with the systemic delivery of oligonucleotides. In recent years, the role of miRNAs in hepatocellular carcinoma (HCC) has been established with molecular studies and the development of animal models. These studies have also provided the basis for evaluating the therapeutic potential of miRNAs, or anti-miRNAs. In general, the safety of miRNAs has been proven and antitumor activity has been observed. Moreover, because of the absence or presence of mild side effects, the prophylactic use of miRNA-based approaches may be foreseen.

Abnormal expression of EMT-related proteins, S100A4, vimentin and E-cadherin, is correlated with clinicopathological features and prognosis in HCC

We determined the expression of epithelial-mesenchymal transition (EMT) indicator proteins, E-cadherin (E-cad), vimentin (VIM), mucin 1 (MUC1) and S100 calcium-binding protein A4 (S100A4) in hepatocellular carcinoma (HCC) patient tissue samples. We also investigated the relationship between the expression of these proteins and clinicopathologic factors in HCC. Finally, we assessed the potential value of these markers as prognostic indicators of survival in HCC patients. The expression of E-cad, VIM, MUC1 and S100A4 EMT indicator proteins was assessed in tissue microarray HCC tissue sections and corresponding peritumoral normal tissues by immunohistochemistry. In addition, the expression for the four EMT indicator proteins was correlated with clinicopathological features of HCC and patient outcome. Comparison of clinicopathological characteristics and immunohistochemistry by χ(2) analysis revealed that downregulation of E-cad in HCC was significantly associated with later TNM cancer stage (P = 0.012), gross classification (P = 0.018), regional lymph node metastasis (P = 0.036) and liver cirrhosis (P = 0.028). Increased S100A4 expression in HCC was significantly associated with differentiation (P = 0.032), tumor with a complete fibrous capsule (P = 0.031) and portal vein invasion (P = 0.038). High VIM expression in HCC was significantly associated with high serum α-fetoprotein levels (P = 0.016). We also observed that low E-cad expression was significantly associated with overexpression of VIM (P = 0.001). Kaplan-Meier survival and Cox regression analysis revealed that low E-cad expression (HR = 0.164, 95 % CI 0.072 to 0.373, P < 0.001) and high serum α-fetoprotein levels (HR = 2.202, 95 % CI 1.054 to 4.598, P = 0.036) were independent prognostic factors in HCC. Our study demonstrates that high S100A4 and VIM expression and low E-cad expression correlate with an aggressive, malignant phenotype in HCC. These results also support a role for E-cad as a prognostic factor in HCC.

Clinical significance of microRNA 138 and cyclin D3 in hepatocellular carcinoma

BACKGROUND

MicroRNA 138 (miR-138) is recently shown to inhibit tumor growth and block cell cycle arrest of hepatocellular carcinoma (HCC) by targeting cyclin D3 (CCND3). The aim of this study was to investigate the clinical significance of miR-138 and CCND3 in human HCC, which remains unclear.

METHODS

Quantitative real-time polymerase chain reaction analysis was performed to detect the expression levels of miR-138 and CCND3 messenger RNA (mRNA) in 180 self-pairs of HCC and noncancerous liver tissues.

RESULTS

Compared with noncancerous liver tissues, the expression levels of miR-138 in HCC tissues were significantly downregulated (P < 0.001), whereas the expression levels of CCND3 mRNA in HCC tissues were significantly upregulated (P < 0.001). There was a negative correlation between miR-138 and CCND3 mRNA expression in HCC tissues (r = -0.56, P = 0.02). Additionally, statistical analysis showed that the combined miR 138 downregulation and CCND3 upregulation (miR-138-low-CCND3-high) was significantly associated with the advanced tumor-node-metastasis stage (P = 0.008) and the presence of portal vein invasion (P = 0.008) and lymph node metastasis (P = 0.01). More importantly, a significant trend was identified between the combined expression of miR-138-low-CCND3-high in HCC and worsening clinical prognosis. Multivariate survival analysis further recognized miR-138-low-CCND3-high expression as an independent prognostic factor for patients with HCC.

CONCLUSIONS

Our data suggest that the combined expression of miR-138 and its direct target CCND3 may be correlated with significant characteristics of HCC. MiR-138 downregulation and CCND3 upregulation maybe concurrently associated with prognosis in patients with HCC.

Targeted therapies in the treatment of advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common liver cancer and the third leading cause of cancer death. It has been a major worldwide health problem with more new cases being diagnosed each year. The current available therapies for patients with advanced HCC are extremely limited. Therefore, it is of great clinical interests to develop more effective therapies for systemic treatment of advanced HCC. Several promising target-based drugs have been tested in a number of clinical trials. One breakthrough of these efforts is the approved clinical use of sorafenib in patients with advanced HCC. Targeted therapies are becoming an attractive option for the treatment of advanced HCC. In this review, we summarize the most recent progress in clinical targeted treatments of advanced HCC.

Association of IL27 gene polymorphisms and HBV-related hepatocellular carcinoma risk in a Chinese population

BACKGROUND AND OBJECTIVE

Hepatocellular carcinoma (HCC) is multifactorial, and the genetic background may be a crucial etiologic factor. Interleukin-27 (IL-27) is a novel IL-12 family member which plays an important role in antitumor immunity. Mutations in the IL27 gene may lead to altered cytokine production and/or activity and thus modulate individual's susceptibility to HCC. In this study, we investigated the association between IL27 gene polymorphisms and HBV-related diseases risk in a Chinese population.

METHODS

Studied subjects were divided into four groups: 112 patients with chronic hepatitis B (CHB), 65 patients with hepatitis B virus (HBV)-related liver cirrhosis (LC), 107 patients with HBV-related HCC, and 105 healthy controls. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy and polymerase chain reaction-sequence specific primer (PCR-SSP) strategy were used to detect IL27 gene -964A/G and 2905T/G polymorphisms, respectively. DNA sequencing was used to validate genotype results.

RESULTS

There were no significant differences in the genotype and allele frequencies of IL27 gene polymorphisms between the groups of patients and healthy controls. Furthermore, no association was found between the distributions of the haplotypes and HCC risk.

CONCLUSION

These findings indicate that the genetic variants in IL27 gene may not contribute to HCC development. Further studies with large sample size should be conducted to validate this association.

The human sulfatase 2 inhibitor 2,4-disulfonylphenyl-tert-butylnitrone (OKN-007) has an antitumor effect in hepatocellular carcinoma mediated via suppression of TGFB1/SMAD2 and Hedgehog/GLI1 signaling

Human sulfatase 2 (SULF2) functions as an oncoprotein in hepatocellular carcinoma (HCC) development by promoting tumor growth and metastasis via enhancement of fibroblast growth factor-2/extracellular signal-regulated kinase and WNT/β-catenin signaling. Recent results implicate that SULF2 activates the transforming growth factor beta (TGFB) and Hedgehog/GLI1 pathways in HCC. OKN-007 is a novel phenyl-sulfonyl compound that inhibits the enzymatic activity of SULF2. To investigate the antitumor effect of OKN-007 in HCC, we treated Huh7 cells, which express high levels of SULF2, with OKN-007 and found that it significantly promoted tumor cell apoptosis and inhibited cell proliferation, viability, and migration. To understand the action of OKN-007 on SULF2, we used Huh7 cells which normally express SULF2 and Hep3B cells that do not normally express SULF2. Utilizing Huh7 cells transfected with short hairpin RNA targeting SULF2 and transfection of Hep3B cells with a SULF2 plasmid to enhance SULF2 expression, we showed that the antitumor activity of OKN-007 was more pronounced in cells expressing SULF2. Furthermore, in vivo experiments verified that OKN-007 repressed tumor growth significantly. These results identify SULF2 as an important target of the antitumor effect of OKN-007. To determine the molecular mechanism of the antitumor effect of OKN-007, both TGFB1/SMAD and Hedgehog/GLI1 signaling pathway activity were measured by Western blot and SMAD- or GLI-reporter luciferase assays. We found that both signaling pathways were inhibited by OKN-007. Together, these results show that OKN-007 can suppress TGFB1/SMAD and Hedgehog/GLI1 signaling via its inhibition of SULF2 enzymatic activity. We conclude that OKN-007 or more potent derivatives may be promising agents for the treatment of HCC.

Pro-apoptotic effects of tectorigenin on human hepatocellular carcinoma HepG2 cells

AIM: To investigate the effects of tectorigenin on human hepatocellular carcinoma (HCC) HepG2 cells.

METHODS: Tectorigenin, one of the main components of rhizome of Iris tectorum, was prepared by simple methods, such as extraction, filtration, concentration, precipitation and recrystallization. HepG2 cells were incubated with tectorigenin at different concentrations, and their viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was detected by morphological observation of nuclear change, agarose gel electrophoresis of DNA ladder, and flow cytometry with Hoechst 33342, Annexin V-EGFP and propidium iodide staining. Generation of reactive oxygen species was quantified using DCFH-DA. Intracellular Ca²⁺ was monitored by Fura 2-AM. Mitochondrial membrane potential was monitored using Rhodamine 123. Release of cytochrome c from mitochondria to cytosol was detected by Western blotting. Activities of caspase-3, -8 and -9 were investigated by Caspase Activity Assay Kit.

RESULTS: The viability of HepG2 cells treated by tectorigenin decreased in a concentration- and time-dependent manner. The concentration that reduced the number of viable HepG2 cells by 50% (IC₅₀) after 12, 24 and 48 h of incubation was 35.72 mg/L, 21.19 mg/L and 11.06 mg/L, respectively. However, treatment with tectorigenin at 20 mg/L resulted in a very slight cytotoxicity to L02 cells after incubation for 12, 24 or 48 h. Tectorigenin at a concentration of 20 mg/L greatly inhibited the viability of HepG2 cells and induced the condensation of chromatin and fragmentation of nuclei. Tectorigenin induced apoptosis of HepG2 cells in a time- and dose-dependent manner. Compared with the viability rate, induction of apoptosis was the main mechanism of the anti-proliferation effect of tectorigenin in HepG2 cells. Furthermore, tectorigenin-induced apoptosis of HepG2 cells was associated with the generation of reactive oxygen species, increased intracellular [Ca²⁺]_i, loss of mitochondrial membrane potential, translocation of cytochrome c, and activation of caspase-9 and -3.

CONCLUSION: Tectorigenin induces apoptosis of HepG2 cells mainly via mitochondrial-mediated pathway, and produces a slight cytotoxicity to L02 cells.

Targeted therapy for hepatocellular carcinoma: novel agents on the horizon

Hepatocellular carcinoma (HCC) is the most common liver cancer, accounting for 90% of primary liver cancers. In the last decade it has become one of the most frequently occurring tumors worldwide and is also considered to be the most lethal of the cancer systems, accounting for approximately one third of all malignancies. Although the clinical diagnosis and management of early-stage HCC has improved significantly, HCC prognosis is still extremely poor. Furthermore, advanced HCC is a highly aggressive tumor with a poor or no response to common therapies. Therefore, new effective and well-tolerated therapy strategies are urgently needed. Targeted therapies have entered the field of anti-neoplastic treatment and are being used on their own or in combination with conventional chemotherapy drugs. Molecular-targeted therapy holds great promise in the treatment of HCC. A new therapeutic opportunity for advanced HCC is the use of sorafenib (Nexavar). On the basis of the recent large randomized phase III study, the Sorafenib HCC Assessment Randomized Protocol (SHARP), sorafenib has been approved by the FDA for the treatment of advanced HCC. Sorafenib showed to be able to significantly increase survival in patients with advanced HCC, establishing a new standard of care. Despite this promising breakthrough, patients with HCC still have a dismal prognosis, as it is currently the major cause of death in cirrhotic patients. Nevertheless, the successful results of the SHARP trial underscore the need for a comprehensive understanding of the molecular pathogenesis of this devastating disease. In this review we summarize the most important studies on the signaling pathways implicated in the pathogenesis of HCC, as well as the newest emerging drugs and their potential use in HCC management.

Targeting the insulin-like growth factor 1 receptor (IGF1R) signaling pathway for cancer therapy

INTRODUCTION

The IGF system controls growth, differentiation, and development at the cellular, organ and organismal levels. IGF1 receptor (IGF1R) signaling is dysregulated in many cancers. Numerous clinical trials are currently assessing therapies that inhibit either growth factor binding or IGF1R itself. Therapeutic benefit, often in the form of stable disease, has been reported for many different cancer types.

AREAS COVERED

Canonical IGF signaling and non-canonical pathways involved in carcinogenesis. Three recent insights into IGF1R signaling, namely hybrid receptor formation with insulin receptor (INSR), insulin receptor substrate 1 nuclear translocation, and evidence for IGF1R/INSR as dependence receptors. Different approaches to targeting IGF1R and mechanisms of acquired resistance. Possible mechanisms by which IGF1R signaling supports carcinogenesis and specific examples in different human tumors.

EXPERT OPINION

Pre-clinical data justifies IGF1R as a target and early clinical trials have shown modest efficacy in selected tumor types. Future work will focus upon assessing the usefulness or disadvantages of simultaneously targeting the IGF1R and INSR, biomarker development to identify potentially responsive patients, and the use of IGF1R inhibitors in combination therapies or as an adjunct to conventional chemotherapy.

PKI-587 and sorafenib targeting PI3K/AKT/mTOR and Ras/Raf/MAPK pathways synergistically inhibit HCC cell proliferation

BACKGROUND

Deregulated Ras/Raf/MAPK and PI3K/AKT/mTOR signaling pathways are found in hepatocellular carcinoma (HCC). This study aimed to test the inhibitory effects of PKI-587 and sorafenib as single agents or in combination on HCC (Huh7 cell line) proliferation.

MATERIALS AND METHODS

(3)H-thymidine incorporation and MTT assay were used to assess Huh7 cell proliferation. Phosphorylation of the key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways was detected by Western blot.

RESULTS

We found that PKI-587 is a more potent PI3K/mTOR inhibitor than PI-103. Combination of PKI-587 and sorafenib was a more effective inhibitor of Huh7 proliferation than the combination of PI-103 and sorafenib. Combination of PKI-587 and sorafenib synergistically inhibited epidermal growth factor (EGF)-stimulated Huh7 proliferation compared with monodrug therapy. EGF increased phosphorylation of Ras/Raf downstream signaling proteins MEK and ERK; EGF-stimulated activation was inhibited by sorafenib. However, sorafenib, as a single agent, increased AKT (Ser473) phosphorylation. EGF-stimulated AKT (ser473) activation was inhibited by PKI-587. PKI-587 is a potent inhibitor of AKT (Ser473), mTOR (Ser2448), and S6K (Thr389) phosphorylation; in contrast, rapamycin stimulated mTOR complex 2 substrate AKT(Ser473) phosphorylation although it inhibited mTOR complex 1 substrate S6K phosphorylation. PKI-587, as a single agent, stimulated MEK and ERK phosphorylation. However, when PKI-587 and sorafenib were used in combination, they inhibited all the tested kinases in the Ras/Raf /MAPK and PI3K/AKT/mTOR pathways.

CONCLUSION

The combination of PKI-587 and sorafenib has the advantage over monodrug therapy on inhibition of HCC cell proliferation by blocking both PI3K/AKT/mTOR and Ras/Raf/MAPK signaling pathways.

AKR1B10 expression is associated with less aggressive hepatocellular carcinoma: a clinicopathological study of 168 cases

BACKGROUND/AIMS

The detoxification enzyme AKR1B10, a member of the aldo-keto reductase superfamily, is discussed as a new biomarker candidate for hepatocellular carcinoma (HCC). Only rare clinicopathological data on AKRB1B10 in HCC exist. This retrospective study determines the diagnostic and prognostic relevance of AKR1B10 expression in HCC and its relationship to a series of clinicopathological parameters including underlying aetiological factors.

METHODS

A series of 168 patients with HCCs treated either by surgical resection (n=92) or liver transplantation (n=76) were investigated after construction of a tissue micro-array. Immunohistochemically confirmed AKR1B10 expression was correlated with clinicopathologically relevant parameters as well as proliferative activity (indicated by Ki-67 immunostaining) and apoptosis (terminal deoxyribonucleotide transferase-mediated dUTP nick-end labelling).

RESULTS

AKR1B10 overexpression is significantly associated with lower pT-classification (P=0.030) and highly statistically associated with an underlying viral hepatitis (P<0.001) and the presence of cirrhosis (P<0.001). In addition, loss of AKR1B10 expression correlates with increased proliferative activity (Ki-67, P=0.001). Kaplan-Meier survival analysis of the resection group reveals a poorer prognosis in patients with AKR1B10-negative HCCs compared with patients with strongly positive HCCs (P=0.046).

CONCLUSIONS

This study confirms and expands data on the expression of AKR1B10 in HCC, suggesting that this enzyme is a valuable novel biomarker candidate for staging of HCC, especially in patients with underlying virus hepatitis or cirrhosis, and may present a new therapeutic target for multimodal therapy concepts. We confirm its prognostic value and conclude that high expression of AKR1B10 reflects a less aggressive tumour behaviour.

XRCC1 genetic polymorphism Arg399Gln and hepatocellular carcinoma risk: a meta-analysis

BACKGROUND

Studies investigating the association between X-ray repair cross-complementing group 1 (XRCC1) genetic polymorphism Arg399Gln and hepatocellular carcinoma (HCC) risk report conflicting results. The aim of this study was to quantitatively summarize the evidence for such a relationship.

METHODS

Two investigators independently searched the Medline, Embase, CNKI and Chinese Biomedicine Database. Summary odds ratios (ORs) and 95% confidence intervals (95% CIs) for XRCC1 polymorphism and HCC were calculated in a fixed-effects model (the Mantel-Haenszel method) and a random-effects model (the DerSimonian and Laird method) when appropriate. The pooled ORs were performed for a codominant model (Gln/Gln vs. Arg/Arg, Arg/Gln vs. Arg/Arg), a dominant model (Gln/Gln+Arg/Gln vs. Arg/Arg) and a recessive model (Gln/Gln vs. Arg/Gln+Arg/Arg).

RESULTS

This meta-analysis included 11 case-control studies, which included 2208 HCC cases and 3265 controls. Overall, the variant genotypes (Gln/Gln and Arg/Gln) of Arg399Gln were not associated with HCC risk when compared with the wild-type Arg/Arg homozygote (Gln/Gln vs. Arg/Arg, OR=1.01, 95% CI=0.79-1.28; Arg/Gln vs. Arg/Arg, OR=1.09, 95% CI=0.81-1.45). Similarly, no associations were found in the dominant and recessive models (dominant model, OR=1.12, 95% CI=0.85-1.47; recessive model, OR=0.99, 95% CI=0.79-1.25). Limiting the analysis to the studies within Hardy-Weinberg equilibrium, the results were persistent and robust. When stratifying for ethnicity, country/region and source of controls, no evidence of a significant association was observed in any subgroup. No publication bias was found in the present study.

CONCLUSION

No association is found between the XRCC1 polymorphism Arg399Gln and the risk of HCC.