Elevated hepatocyte growth factor expression as an autocrine c-Met activation mechanism in acquired resistance to sorafenib in hepatocellular carcinoma cells

Percentage genome change and chromosome 7q amplification predict sorafenib response in advanced hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) may arise from genomic instability and has dismal outcome. Sorafenib is the first-line treatment for advanced stage HCC, but its therapeutic efficacy is less than 50%. Biomarkers for predicting the therapeutic efficacy of sorafenib administration to patients with advanced HCC are required. Here, we evaluated the role of chromosomal copy number aberrations (CNAs) in patients with advanced HCC who were treated with sorafenib along with their drug response.

Methods

The response to sorafenib treatment of twenty-three HCC patients who developed advanced recurrence after partial hepatectomy was analyzed using the modified Response Evaluation Criteria in Solid Tumors (mRECIST). Formalin fixed paraffin embedded (FFPE) tissue specimens obtained after tumor resection were analyzed using the Affymetrix OncoScan® FFPE assay.

Results

From the 23 patients analyzed in this study, 7 (30.4%) had complete/partial response to sorafenib (CR/PR), 7 (30.4%) had stable disease (SD), and 9 (39.1%) had progressive disease (PD). The mean genome-wide percentage of genome change acquisition via the OncoScan platform was 19.8% for patients with CR/PR/SD and 50.02% in the PD group (p = 0.055). Percentage of genome change above 33% was associated with adverse outcomes for sorafenib treatment in the time-to-progression analysis (p = 0.007) and overall survival (p = 0.096). Among these CNAs, amplification of chromosome 7q, containing the multidrug resistance gene ATP Binding Cassette Subfamily B Member 1 (ACBC1), significantly associated with poor overall survival (p = 0.004) and time-to-progression (p < 0.001).

Conclusions

Higher percentage genome change and amplification of chromosome 7q in advanced HCC is associated with sorafenib resistance.

Profile of Cabozantinib for the Treatment of Hepatocellular Carcinoma: Patient Selection and Special Considerations

Management of advanced hepatocellular carcinoma is challenging. With an increasing number of options for the first and second-line treatment, understanding and developing optimal systemic treatment strategies are crucial. In second line, two tyrosine kinase inhibitors (TKI) and one monoclonal antibody have been approved after sorafenib by both the European Medicines Agency and the Food and Drug Administration based on the results of phase 3 trials: cabozantinib, regorafenib and ramucirumab. Cabozantinib has demonstrated an improved overall survival and progression-free survival in the phase 3 CELESTIAL study in second and third line, in patients in good general condition (performance status 0-1) and with a normal liver function Child-Pugh class A. Analysis of subgroups has shown that even elderly patients over 65 years, or patients with high baseline alpha-fetoprotein ≥400 ng/mL benefit from cabozantinib. The choice in second-line between the three drugs should be based on factors such as previous tolerance of sorafenib, safety profile of drugs and quality of life. In this review, we will analyze clinical data available on cabozantinib, clarifying the choice between the different possible treatments. However, the upcoming of a new standard in first line with the combination atezolizumab and bevacizumab will change the game and will warrant further investigations to define the accurate subsequent sequence of TKIs. Cabozantinib is also actually tested in first-line in combination with atezolizumab, results of the phase 3 COSMIC trial are eagerly awaited.

Diospyros kaki leaves inhibit HGF/Met signaling-mediated EMT and stemness features in hepatocellular carcinoma

Persimmon (Diospyros kaki L.f.) trees are widely cultivated for their edible fruits in Asia. D. kaki leaves are abundant in phytochemicals that have numerous medicinal properties. Hepatocyte growth factor (HGF) and its receptor Met lead to poor prognosis via the promotion of metastasis and chemoresistance in hepatocellular carcinoma (HCC). Therefore, inhibitors targeting the HGF/Met pathway are regarded as promising drugs against HCC. Here, we investigated the effects of D. kaki leaves on HGF-induced epithelial-to-mesenchymal transition (EMT) and stemness traits in HCC. The ethanol extract of D. kaki leaves (EEDK) markedly suppressed HGF-mediated cell migration and invasion through upregulation of CDH1 and downregulation of SNAI1, VIM, MMP1, MMP2, and MMP9. Moreover, EEDK increased the cytotoxicity of sorafenib, which was reduced by HGF, and decreased the expression of the stemness markers KRT19 and CD44. Additionally, we found a clear correlation between stemness and EMT markers in HCC patients. Importantly, EEDK reduced Met activity and attenuated HGF-mediated activation of JNK/c-Jun. Our findings provide new evidence that EEDK can ameliorate HCC with poor prognosis and aggressive phenotype by blocking HGF/Met signaling.

Mini-Review: Cabozantinib in the Treatment of Advanced Renal Cell Carcinoma and Hepatocellular Carcinoma

Cabozantinib is an oral, tyrosine-kinase inhibitor with potent activity against VEGFR2 and MET, along with multiple other tyrosine kinases involved in cancer development and progression. Herein, we will focus on preclinical and clinical studies leading to the approval of cabozantinib in advanced renal cell carcinoma and hepatocellular carcinoma. Covered studies include NCT01100619, CABOSUN, METEOR, NCT00940225 and the CELESTIAL trial. Finally, we review future directions of cabozantinib development by highlighting some ongoing clinical trials.

A Novel Function for KLF4 in Modulating the De-differentiation of EpCAM-/CD133- nonStem Cells into EpCAM+/CD133+ Liver Cancer Stem Cells in HCC Cell Line HuH7

The complex and heterogeneous nature of hepatocellular carcinoma (HCC) hampers the identification of effective therapeutic strategies. Cancer stem cells (CSCs) represent a fraction of cells within tumors with the ability to self-renew and differentiate, and thus significantly contribute to the formation and maintenance of heterogeneous tumor mass. Increasing evidence indicates high plasticity in tumor cells, suggesting that non-CSCs could acquire stem cell properties through de-differentiation or reprogramming processes. In this paper, we reveal KLF4 as a transcription factor that can induce a CSC-like phenotype in non-CSCs through upregulating the EpCAM and E-CAD expression. Our studies indicated that KLF4 could directly bind to the promoter of EpCAM and increase the number of EpCAM⁺/CD133⁺ liver cancer stem cells (LCSCs) in the HuH7 HCC cell line. When KLF4 was overexpressed in EpCAM⁻/CD133⁻ non-stem cells, the expressions of hepatic stem/progenitor cell genes such as CK19, EpCAM and LGR5 were significantly increased. KLF4 overexpressing non-stem cells exhibited greater cell viability upon sorafenib treatment, while the cell migration and invasion capabilities of these cells were suppressed. Importantly, we detected an increased membranous expression and colocalization of β-CAT, E-CAD and EpCAM in the KLF4-overexpressing EpCAM⁻/CD133⁻ non-stem cells, suggesting that this complex might be required for the cancer stem cell phenotype. Moreover, our in vivo xenograft studies demonstrated that with a KLF4 overexpression, EpCAM⁻/CD133⁻ non-stem cells attained an in vivo tumor forming ability comparable to EpCAM⁺/CD133⁺ LCSCs, and the tumor specimens from KLF4-overexpressing xenografts had increased levels of both the KLF4 and EpCAM proteins. Additionally, we identified a correlation between the KLF4 and EpCAM protein expressions in human HCC tissues independent of the tumor stage and differentiation status. Collectively, our data suggest a novel function for KLF4 in modulating the de-differentiation of tumor cells and the induction of EpCAM⁺/CD133⁺ LCSCs in HuH7 HCC cells.

Systemic Therapy for Primary Liver Tumors: Cholangiocarcinoma and Hepatocellular Carcinoma

In the past decade, there has been significant progress in the treatment of primary liver cancer. There has been increasing knowledge of the molecular alterations occurring in these tumors, which is now being translated into patient care. Ongoing clinical trials will further advance the therapeutic options available to patients, including the introduction of molecular targeted therapeutics and immunotherapy approaches. Critical to the success of these new drugs, is the appropriate use of them in the clinic to maximize efficacy and limit toxicity.

State of the Art: Toward Improving Outcomes of Lung and Liver Tumor Biopsies in Clinical Trials-A Multidisciplinary Approach

PURPOSE

National Cancer Institute (NCI)-sponsored clinical trial network studies frequently require biopsy specimens for pharmacodynamic and molecular biomarker analyses, including paired pre- and post-treatment samples. The purpose of this meeting of NCI-sponsored investigators was to identify local institutional standard procedures found to ensure quantitative and qualitative specimen adequacy.

METHODS

NCI convened a conference on best biopsy practices, focusing on the clinical research community. Topics discussed were (1) criteria for specimen adequacy in the personalized medicine era, (2) team-based approaches to ensure specimen adequacy and quality control, and (3) risk considerations relevant to academic and community practitioners and their patients.

RESULTS AND RECOMMENDATIONS

Key recommendations from the convened consensus panel included (1) establishment of infrastructure for multidisciplinary biopsy teams with a formalized information capture process, (2) maintenance of standard operating procedures with regular team review, (3) optimization of tissue collection and yield methodology, (4) incorporation of needle aspiration and other newer techniques, and (5) commitment of stakeholders to use of guideline documents to increase awareness of best biopsy practices, with the goal of universally improving tumor biopsy practices.

Tumour evolution in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common form of primary liver cancer, typically develops on the background of chronic liver disease and is an aggressive disease with dismal prognosis. Studies using next-generation sequencing of multiple regions of the same tumour nodule suggest different patterns of HCC evolution and confirm the high molecular heterogeneity in a subset of patients. Different hypotheses have been proposed to explain tumour evolution, including clonal selection or neutral and punctuated acquisition of genetic alterations. In parallel, data indicate a fundamental contribution of nonmalignant cells of the tumour microenvironment to cancer clonal evolution. Delineating these dynamics is crucial to improve the treatment of patients with HCC, and particularly to help understand how HCC evolution drives resistance to systemic therapies. A number of new minimally invasive techniques, such as liquid biopsies, could help track cancer evolution in HCC. These tools might improve our understanding of how systemic therapies affect tumour clonal composition and could facilitate implementation of real-time molecular monitoring of patients with HCC.

The Function of the HGF/c-Met Axis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, leading to a large global cancer burden. Hepatocyte growth factor (HGF) and its high-affinity receptor, mesenchymal epithelial transition factor (c-Met), are closely related to the onset, progression, and metastasis of multiple tumors. The HGF/c-Met axis is involved in cell proliferation, movement, differentiation, invasion, angiogenesis, and apoptosis by activating multiple downstream signaling pathways. In this review, we focus on the function of the HGF/c-Met axis in HCC. The HGF/c-Met axis promotes the onset, proliferation, invasion, and metastasis of HCC. Moreover, it can serve as a biomarker for diagnosis and prognosis, as well as a therapeutic target for HCC. In addition, it is closely related to drug resistance during HCC treatment.

Liver X Receptor Agonism Sensitizes a Subset of Hepatocellular Carcinoma to Sorafenib by Dual-Inhibiting MET and EGFR

Sorafenib is the first approved systemic therapy for advanced hepatocellular carcinoma (HCC) and is the first-line choice in clinic. Sustained activation of receptor tyrosine kinases (RTKs) is associated with low efficacy of sorafenib in HCC. Activation of liver X receptor (LXR) has been reported to inhibit some RTKs. In this study, we found that the LXR agonist enhanced the anti-tumor activity of sorafenib in a subset of HCC cells with high LXR-β/α gene expression ratio. Mechanically, the activation of LXR suppressed sorafenib dependent recruitment of MET and epidermal growth factor receptor (EGFR) in lipid rafts through cholesterol efflux. Our findings imply that LXR agonist can serve as a potential sensitizer to enhance the anti-tumor effect of sorafenib.

Cabozantinib exposure-response analyses of efficacy and safety in patients with advanced hepatocellular carcinoma

Cabozantinib, a multi-kinase inhibitor, is approved in the United States and European Union for treatment of patients with hepatocellular carcinoma following prior sorafenib treatment. In the Phase III CELESTIAL trial, hepatocellular carcinoma patients receiving cabozantinib showed longer overall survival (OS) and progression-free survival (PFS) than those receiving placebo. The approved cabozantinib (Cabometyx^®) dose is 60 mg once daily with allowable dose modifications to manage adverse events (AE). Time-to-event Cox proportional hazard exposure-response (ER) models were developed to characterize the relationship between predicted cabozantinib exposure and the likelihood of various efficacy and safety endpoints. The ER models were used to predict hazard ratios (HR) for efficacy and safety endpoints for starting doses of 60, 40, or 20 mg daily. Statistically significant relationships between cabozantinib exposure and efficacy and safety endpoints were observed. For efficacy endpoints, predicted HR were lower for OS and PFS at 40 and 60 mg relative to the 20 mg dose: HR for death (OS) are 0.84 (40 mg) and 0.70 (60 mg); HR for disease progression/death (PFS) are 0.73 (40 mg) and 0.62 (60 mg). For safety endpoints, predicted HR were lower for palmar-plantar erythrodysaesthesia (PPE), diarrhea, and hypertension at 20 or 40 mg relative to the 60 mg dose: HR for PPE are 0.31 (20 mg) and 0.66 (40 mg); HR for diarrhea are 0.61 (20 mg) and 0.86 (40 mg); HR for hypertension are 0.46 (20 mg) and 0.76 (40 mg). The rate of dose modifications was predicted to increase in patients with lower cabozantinib apparent clearance. OS and PFS showed the greatest benefit at the 60 mg dose. However, higher cabozantinib exposure was predicted to increase the likelihood of AE and subsequent dose reductions appeared to decrease these risks.

Targeted agents for second-line treatment of advanced hepatocellular carcinoma

Over the past ten years, sorafenib, a multikinase inhibitor, has been the standard of care for patients with unresectable hepatocellular carcinoma (HCC) and well-preserved liver function. Recently, lenvatinib, a different multikinase inhibitor, was shown to be non-inferior to sorafenib, in terms of survival, while all other agents previously tested failed to prove non-inferiority (or superiority) when compared to sorafenib. Similarly, in the second-line setting, most investigational drugs failed to provide better survival outcomes than placebo. However, in the last 2 years three positive phase III trials have been published in this setting. The RESORCE trial, a phase III study evaluating regorafenib in HCC patients who experienced disease progression after first-line treatment with sorafenib, showed better outcomes with regorafenib compared to placebo. More recently, the phase III CELESTIAL trial demonstrated the superiority of cabozantinib, a multikinase inhibitor targeting vascular endothelial growth factor receptor, MET, and AXL, vs placebo in the second- and third-line setting in patients progressing on or intolerant to sorafenib. The survival benefits of a sustained anti-angiogenic inhibition were demonstrated also with ramucirumab in the phase III REACH-2 trial in patients previously treated with sorafenib and who had high baseline alpha-fetoprotein levels. Overall, the adverse events reported in these trials were in line with the known safety profiles of the tested agents. After nearly a decade of a certain degree of stagnation, we are now witnessing a period of novel therapeutic advances with multikinase inhibitors and monoclonal antibodies that will likely change the treatment scenario of HCC.

Reactive Oxygen Species-Induced Lipid Peroxidation in Apoptosis, Autophagy, and Ferroptosis

Reactive oxygen species- (ROS-) induced lipid peroxidation plays a critical role in cell death including apoptosis, autophagy, and ferroptosis. This fundamental and conserved mechanism is based on an excess of ROS which attacks biomembranes, propagates lipid peroxidation chain reactions, and subsequently induces different types of cell death. A highly evolved sophisticated antioxidant system exists that acts to protect the cells from oxidative damage. In this review, we discussed how ROS propagate lipid peroxidation chain reactions and how the products of lipid peroxidation initiate apoptosis and autophagy in current models. We also discussed the mechanism of lipid peroxidation during ferroptosis, and we summarized lipid peroxidation in pathological conditions of critical illness. We aim to bring a more global and integrative sight to know how different ROS-induced lipid peroxidation occurs among apoptosis, autophagy, and ferroptosis.

Cabozantinib for the treatment of hepatocellular carcinoma

Introduction: The randomized, placebo-controlled, phase III CELESTIAL trial demonstrated statistically and clinically significant improvement in overall survival with cabozantinib in patients with advanced hepatocellular carcinoma (HCC) previously treated with sorafenib. Most frequently reported adverse events included palmar-plantar erythrodysesthesia, hypertension, increased aspartate aminotransferase, fatigue, and diarrhea. Areas covered: In this review we analyze and discuss preclinical and clinical data of cabozantinib. We summarize efficacy and safety results of phase II and III trials of cabozantinib in the treatment of patients with advanced HCC and we present ongoing trials of cabozantinib in combination with checkpoint inhibitors. Expert opinion: Cabozantinib is a new second-line and the only third-line treatment for patients with advanced HCC, nevertheless some data are still missing to better inform clinical decisions on how to treat specific patient populations. Next trials designs will have to incorporate heavy efforts in terms of translational research to maximize the benefits of such treatments.

Cabozantinib in patients with hepatocellular carcinoma failing previous treatment with sorafenib

Over the past 10 years, sorafenib has been the only systemic agent approved for the treatment of patients with unresectable hepatocellular carcinoma. Recently, lenvatinib was demonstrated noninferior to sorafenib, and regorafenib and ramucirumab were demonstrated superior to placebo in patients progressing on sorafenib and in patients with elevated α-fetoprotein-failing sorafenib, respectively. Phase I–II trials of immune checkpoint inhibitors reported promising efficacy signals. Recently, the randomized, placebo-controlled, Phase III CELESTIAL trial demonstrated statistically and clinically significant increase in overall survival from 8 months with placebo to 10.2 months with cabozantinib in patients failing sorafenib. Furthermore, the study showed a significant improvement in all the efficacy end points. Main adverse events were palmar–plantar erythrodysesthesia, hypertension, increased aspartate aminotransferase, fatigue and diarrhea.

Monitoring serum proangiogenic cytokines from hepatocellular carcinoma patients treated with sorafenib

BACKGROUND AND AIM

Several factors, including proangiogenic cytokines, have been reported as predictive markers for the treatment effect of sorafenib in patients with hepatocellular carcinoma (HCC); however, most of them were determined based on one-time measurements before treatment.

METHODS

We consecutively recruited 80 advanced HCC patients who were treated with sorafenib prospectively. Serum levels of eight proangiogenic cytokines and the appearance of adverse events were monitored periodically, and their correlations with the prognoses of the patients were evaluated.

RESULTS

Among six significant risk factors for overall survival in univariate analyses, high angiopoietin-2 (hazard ratio, 2.06), high hepatocyte growth factor (hazard ratio, 2.08), and poor performance status before the treatment (hazard ratio, 2.48) were determined as independent risk factors. In addition, high angiopoietin-2 at the time of progressive disease was a marker of short post-progression survival (hazard ratio, 4.27). However, there was no significant variable that predicted short progression-free survival except the presence of hepatitis B virus surface antigen.

CONCLUSIONS

Predictions of overall survival and post-progression survival were possible by periodically measuring serum proangiogenic cytokines, especially angiopoietin-2, in patients with HCC treated with sorafenib.

M2 macrophages mediate sorafenib resistance by secreting HGF in a feed-forward manner in hepatocellular carcinoma

Background

Sorafenib is the only approved first line systemic therapy for advanced hepatocellular carcinoma (HCC) in the last decade. Tumour resistance to sorafenib has been of major obstacles to improve HCC patient survival.

Methods

We polarised THP-1 cells to M1 and M2 macrophages, performed various in vitro assays and developed sorafenib-resistant xenograft models to investigate the role of tumour-associated macrophages (TAM)-secreted molecules in HCC resistance to the targeted therapy.

Results

We demonstrated M2, but not M1, macrophages not only promote proliferation, colony formation and migration of hepatoma cells but also significantly confer tumour resistance to sorafenib via sustaining tumour growth and metastasis by secreting hepatocyte growth factor (HGF). HGF activates HGF/c-Met, ERK1/2/MAPK and PI3K/AKT pathways in tumour cells. Tumour-associated M2 macrophages were accumulated in sorafenib-resistance tumours more than in sorafenib-sensitive tumours in vivo and produced abundant HGF. HGF chemoattracts more macrophages migrated from surrounding area, regulates the distribution of M2 macrophages and increases hepatoma resistance to sorafenib in a feed-forward manner.

Conclusions

Our results provide new insights into the mechanisms of sorafenib resistance in HCC and rationale for developing new trials by combining sorafenib with a potent HGF inhibitor such as cabozantinib to improve the first line systemic therapeutic efficacy.

Regorafenib reverses HGF-induced sorafenib resistance by inhibiting epithelial-mesenchymal transition in hepatocellular carcinoma

Sorafenib resistance is one of the major obstacles towards achieving a better outcome in patients with advanced hepatocellular carcinoma (HCC), in which aberrant activation of the hepatocyte growth factor (HGF)/mesenchymal‐epithelial transition pathway is frequently observed. Here, we report that HCC cells develop sorafenib resistance following HGF stimulation. Furthermore, HGF activates the downstream extracellular signal‐related kinase (ERK) and signal transducer and activator of transcription 3 (STAT3) pathway and induces epithelial–mesenchymal transition (EMT) by up‐regulating Snail in HCC cells. Inhibition of ERK and STAT3 abolished the rescue effect of HGF by down‐regulating Snail and EMT. Moreover, phosphoinositide 3‐kinase/Akt was also activated in HGF‐treated HCC cells, although it had no effect on Snail expression. Notably, we also found that regorafenib reversed HGF‐induced sorafenib resistance by inhibiting ERK and STAT3, and subsequently down‐regulating Snail and EMT. Taken together, our results indicate that HGF induces sorafenib resistance by activating phosporylated (P)‐ERK/Snail/EMT and P‐STAT3/Snail/EMT pathways. Inhibition of P‐ERK and P‐STAT3 by regorafenib can block HGF‐induced EMT, thereby reversing HGF‐induced sorafenib resistance.

Activation of c-Met in cancer cells mediates growth-promoting signals against oxidative stress through Nrf2-HO-1

Any imbalance between reactive oxygen species (ROS) generation and the anti-oxidant capacity lead to cellular oxidative stress. Many chemotherapeutic agents mediate their cytotoxic functions through the generation of ROS. c-Met, a receptor tyrosine kinase, is over-expressed in renal cancer and plays very crucial role(s) in its growth and survival. Here, we show that c-Met activation protected renal cancer cells from ROS, oxidative stress and cytotoxicity induced by the anti-cancer agent sorafenib (used for renal cancer treatment); and it markedly attenuated sorafenib-induced DNA damage. Activated c-Met promoted the anti-apoptotic proteins (Bcl-2 and Bcl-xL) and inhibited apoptotic cleaved caspase-3. We found that the cytoprotective function of c-Met against sorafenib-induced ROS generation and apoptosis was mediated primarily through the activation of anti-oxidant Nrf2-HO-1. c-Met promoted the nuclear localization of Nrf2 and hindered its binding with the inhibitory protein Keap1. Silencing of Nrf2 attenuated the protective action of c-Met against sorafenib-induced oxidative stress. To evaluate the physiological significance of our findings, in a tumor xenograft model, we observed that a combination treatment with pharmacological inhibitors of c-Met and it's anti-oxidant downstream effecter HO-1 markedly reduced the growth of renal tumor in vivo; it increased the oxidative stress, DNA damage and apoptotic markers in the tumor xenografts, along with reduced tumor vessel density. Our observations indicate that the c-Met-Nrf2-HO-1 pathway plays a vital role in relieving ROS-mediated oxidative stress of renal tumors. Targeting this pathway can significantly increase the oxidative stress to promote apoptotic death of cancer cells.

Inhibition of Cyclin-Dependent Kinase 5: A Strategy to Improve Sorafenib Response in Hepatocellular Carcinoma Therapy

Therapeutic options for patients with advanced-stage hepatocellular carcinoma (HCC) are very limited. The only approved first-line treatment is the multi-tyrosine kinase inhibitor sorafenib, which shows low response rates and severe side effects. In particular, the compensatory activation of growth factor receptors leads to chemoresistance and limits the clinical impact of sorafenib. However, combination approaches to improve sorafenib have failed. Here we investigate the inhibition of cyclin-dependent kinase 5 (Cdk5) as a promising combination strategy to improve sorafenib response in HCC. Combination of sorafenib with Cdk5 inhibition (genetic knockdown by short hairpin RNA or CRISPR/Cas9 and pharmacologic inhibition) synergistically impaired HCC progression in vitro and in vivo by inhibiting both tumor cell proliferation and migration. Importantly, these effects were mediated by a mechanism for Cdk5: A liquid chromatography-tandem mass spectrometry-based proteomic approach revealed that Cdk5 inhibition interferes with intracellular trafficking, a process crucial for cellular homeostasis and growth factor receptor signaling. Cdk5 inhibition resulted in an accumulation of enlarged vesicles and respective cargos in the perinuclear region, considerably impairing the extent and quality of growth factor receptor signaling. Thereby, Cdk5 inhibition offers a comprehensive approach to globally disturb growth factor receptor signaling that is superior to specific inhibition of individual growth factor receptors. Conclusion: Cdk5 inhibition represents an effective approach to improve sorafenib response and to prevent sorafenib treatment escape in HCC. Notably, Cdk5 is an addressable target frequently overexpressed in HCC, and with Dinaciclib, a clinically tested Cdk5 inhibitor is readily available. Thus, our study provides evidence for clinically evaluating the combination of sorafenib and Dinaciclib to improve the therapeutic situation for patients with advanced-stage HCC.

MicroRNA‑200a suppresses migration and invasion and enhances the radiosensitivity of NSCLC cells by inhibiting the HGF/c‑Met signaling pathway

Hepatocyte growth factor (HGF), an activator of the c‑Met signaling pathway, is involved in tumor invasiveness, metastasis and radiotherapy resistance. In the present study, a novel HGF regulatory pathway in lung cancer involving micro-RNAs (miRNAs/miR) is described. Immunohistochemical staining and western blot analyses demonstrated that HGF was upregulated and associated with miR‑200a downregulation in non‑small cell lung cancer (NSCLC) samples compared with normal lung tissues. The association between HGF and miR‑200a was associated with the degree of tumor malignancy and cell migration and invasion. miR‑200a negatively regulated HGF expression by targeting the 3'‑untranslated region of the HGF mRNA. miR‑200a overexpression induced HGF downregulation, decreased NSCLC cell migration and invasion, promoted apoptosis, and decreased cell survival in A549 and H1299 cells in response to ionizing radiation. The present results revealed a previously uncharacterized role of miRNA‑200a in regulating tumor malignancy and radiosensitivity by suppressing HGF expression, a key factor in the HGF/c‑Met pathway.

Costunolide isolated from Vladimiria souliei inhibits the proliferation and induces the apoptosis of HepG2 cells

Costunolide (cos) is one of the major sesquiterpenes isolated from the ethyl acetate soluble fraction of the roots of Vladimiria souliei. In order to explore the effects and molecular mechanism of cos, the anti‑proliferative and apoptotic effects of cos against the human hepatoblastoma HepG2 cell line was examined in vitro in the current study. Cell viability was measured using an MTT assay, and IC50 values (indicating the concentration required to achieve half‑maximal inhibition) were calculated to detect the inhibitory effect of cos on HepG2 cell growth. Cell morphology was subsequently observed under an inverted microscope, and cell cycle distribution and apoptosis were detected using flow cytometric analysis. In addition, changes in the protein expression levels of B‑cell lymphoma 2 (Bcl‑2), Bcl‑2‑associated X protein (Bax), and caspases‑3, ‑8 and ‑9 were detected by western blotting. The results of cell analyses indicated that cos treatment inhibited the proliferation and promoted the apoptosis of HepG2 cells in vitro. Cos markedly induced HepG2 cell apoptosis by arresting the cell cycle at the G2/M phase in a dose‑dependent manner. In terms of the underlying mechanism, cos was revealed to inhibit the anti‑apoptotic capacity of the cells, possibly via upregulating the expression levels of Bax protein and caspases‑3, ‑8 and ‑9, and downregulating the expression of Bcl‑2 protein. Taken together, the results of the present study indicate that cos may be a promising candidate for liver cancer therapy, and have provided an insight into the mechanism of action involved in its anti‑cancer properties.

Chemopreventive and antitumor effects of benzyl isothiocynate on HCC models: A possible role of HGF /pAkt/ STAT3 axis and VEGF

BACKGROUND

Benzyl isothiocyanate (BITC) is a member of the isothiocyanate compounds that found in cruciferous vegetables. BITC has a potential anticancer effect in different types of tumors. Few studies referred to the antineoplastic effect of BITC against HCC. The mechanism of BITC concerning retardation of HCC progression is incompletely understood.

AIM OF THE WORK

This study evaluated the role of HGF, pAkt and STAT3 in BITC induced HCC growth retardation.

METHOD

HCC was induced in mice using diethylnitrosamine (DEN) 75 mg/kg once a week for 4 weeks. BITC 10 and 20 mg/kg was given to mice orally each day for 10 weeks. The HCC cell lines HepG2 and Huh-7 were also used to evaluate the effect of BITC on tumor cells behavior. Immunoassay was used to detect expressions of caspase-3 activity, VEGF, MMP-2, TNF-α, HGF and pAkt. STAT3 expression was detected in liver tissues using immunohistochemical staining.

RESULTS

BITC has a potential role in suppressing hepatic precancerous lesion progression in mice. The drug increased caspase-3 activity in tumor cells and inhibited the angiogenic marker VEGF. It also decreased the metastatic marker MMP-2. This anticancer effect of BITC was observed in DEN treated mice as well as in hepatoma cell lines. The reported antineoplastic activity was correlated with downregulation of HGF and its downstream molecules pAkt and STAT3.

CONCLUSION

The effect of BITC on HGF /pAkt/ STAT3 axis has a potential role in both chemopreventive and chemotherapeutic effects of BITC.

ETS-1 induces Sorafenib-resistance in hepatocellular carcinoma cells via regulating transcription factor activity of PXR

Transcription factor E26 transformation specific sequence 1 (ETS-1) is a primary regulator in the metastasis of human cancer cells, especially hepatocellular carcinoma (HCC) cells; and it would affect the prognosis of HCC patients who received chemotherapies. However, the regulatory role of ETS-1 in the resistance of HCC cells to molecular-targeting agent remains poorly understood. In the present work, we demonstrate that high ETS-1 expression correlates with poor prognosis of advanced HCC patients received Sorafenib treatment. Mechanistically, ETS-1 binds to nuclear Pregnane X receptor (PXR) directly and enhances PXR's transcription factor activity, which further leads to the induction of the PXR's downstream multi-drug resistance related genes. Overexpression of ETS-1 accelerates the metabolic clearance of Sorafenib in HCC cells and leads to the better survival and faster migration of those cells. The therapeutic studies show that ETS-1 promotes the Sorafenib-resistance of HCC tumor models and ETS-1 blockade enhances the anti-tumor capacity of Sorafenib by decreasing PXR activation. Thus, our study suggests that ETS-1 could enhance the activation of PXR and be a potential therapeutic target for overcoming Sorafenib resistance in HCC treatment.

A dual-targeting reconstituted high density lipoprotein leveraging the synergy of sorafenib and antimiRNA21 for enhanced hepatocellular carcinoma therapy

Sorafenib (So) is a multi-target kinase inhibitor extensively used in clinic for hepatocellular carcinoma therapy. It demonstrated strong inhibition both in tumor proliferation and tumor angiogenesis, while hampered by associated cutaneous side-effect and drug resistance. The knockdown of miR-21 with antisense oligonucleotides (antimiRNA21) was regarded as an efficient strategy for increasing tumor sensibility to chemotherapy, which could be employed to appreciate the efficacy of So. Herein, we successfully formulated a dual-targeting delivery system for enhanced hepatocellular carcinoma therapy by encapsulating So and antimiRNA21 in RGD pentapeptide-modified reconstituted high-density lipoprotein (RGD-rHDL/So/antimiRNA21). The RGD and apolipoprotein A-I (ApoA-I) on nanoparticles (NPs) could drive the system simultaneously to tumor neovascular and parenchyma by binding to the overexpressed ανβ3-integrin and SR-B1 receptors, achieving precise delivery of therapeutics to maximize the efficacy. A series in vitro and in vivo experiments revealed that co-delivery of So and antimiRNA21 by RGD-rHDL significantly strengthened the anti-tumor and anti-angiogenic effect of So with negligible toxicity towards major organs, reversed drug-resistance and was capable of remodeling tumor environments. The constructed RGD-rHDL/So/antimiRNA21 with improved efficacy and excellent tumor targeting ability provided new idea for chemo-gene combined therapy in hepatocellular carcinoma.

STATEMENT OF SIGNIFICANCE

Sorafenib (So) is a multi-target kinase inhibitor which was approved by FDA as first-line drug for hepatocellular carcinoma (HCC) therapy. However, long term application of So in clinic was hampered by serious dermal toxicity and drug resistance. Although numerous researchers were devoted to finding alternatives or therapies as combination treatments with So to reach more desired therapeutic efficacy, the therapeutic options were still limited. The present study prepares RGD pentapeptide decorated biomimic reconstituted high-density lipoprotein (rHDL) loaded with So and antimiRNA21 (RGD-rHDL/So/antimiRNA21) for enhanced HCC therapy. The RGD-rHDL/So/antimiRNA21 NPs offer an effective platform for anti-tumor and anti-angiogenesis therapy in HCC and provide new approach to reverse drug-resistance of So for feasible clinical application.

Cabozantinib in Patients with Advanced and Progressing Hepatocellular Carcinoma

BACKGROUND

Cabozantinib inhibits tyrosine kinases, including vascular endothelial growth factor receptors 1, 2, and 3, MET, and AXL, which are implicated in the progression of hepatocellular carcinoma and the development of resistance to sorafenib, the standard initial treatment for advanced disease. This randomized, double-blind, phase 3 trial evaluated cabozantinib as compared with placebo in previously treated patients with advanced hepatocellular carcinoma.

METHODS

A total of 707 patients were randomly assigned in a 2:1 ratio to receive cabozantinib (60 mg once daily) or matching placebo. Eligible patients had received previous treatment with sorafenib, had disease progression after at least one systemic treatment for hepatocellular carcinoma, and may have received up to two previous systemic regimens for advanced hepatocellular carcinoma. The primary end point was overall survival. Secondary end points were progression-free survival and the objective response rate.

RESULTS

At the second planned interim analysis, the trial showed significantly longer overall survival with cabozantinib than with placebo. Median overall survival was 10.2 months with cabozantinib and 8.0 months with placebo (hazard ratio for death, 0.76; 95% confidence interval [CI], 0.63 to 0.92; P=0.005). Median progression-free survival was 5.2 months with cabozantinib and 1.9 months with placebo (hazard ratio for disease progression or death, 0.44; 95% CI, 0.36 to 0.52; P<0.001), and the objective response rates were 4% and less than 1%, respectively (P=0.009). Grade 3 or 4 adverse events occurred in 68% of patients in the cabozantinib group and in 36% in the placebo group. The most common high-grade events were palmar-plantar erythrodysesthesia (17% with cabozantinib vs. 0% with placebo), hypertension (16% vs. 2%), increased aspartate aminotransferase level (12% vs. 7%), fatigue (10% vs. 4%), and diarrhea (10% vs. 2%).

CONCLUSIONS

Among patients with previously treated advanced hepatocellular carcinoma, treatment with cabozantinib resulted in longer overall survival and progression-free survival than placebo. The rate of high-grade adverse events in the cabozantinib group was approximately twice that observed in the placebo group. (Funded by Exelixis; CELESTIAL ClinicalTrials.gov number, NCT01908426 .).

Vacquinol‑1 induces apoptosis in hepatocellular carcinoma cell

Vacquinol‑1 (Vacq), a quinolone derivative, has recently been reported to display potent antitumor effects in glioblastomas by inducing cellular massive vacuolization and cell death. However, whether Vacq induces cytotoxicities in other types of cancers, and the potential underlying mechanism, remain to be investigated. In the present study, it was revealed that Vacq suppressed cell growth and colony formation in the hepatocellular carcinoma (HCC) cell lines BEL7402 and Huh7. In addition, treatment with Vacq increased the number of early and late apoptotic cells as assessed by flow cytometry with fluorescein isothiocyanate‑conjugated Annexin V and propidium iodide double staining. Notably, the effect by Vacq in the tested cells could be inhibited by pretreatment with a broad specificity caspase inhibitor Z‑VAD‑FMK, suggesting that Vacq may induce apoptosis in HCC cells. Morphologically, exposure to Vacq resulted in nuclear fragmentation and the apoptotic body formation in HCC cells. Furthermore, Vacq treatment increased the cleavage of caspase‑3, caspase‑9 and poly(adenosine diphosphate‑ribose) polymerase‑1. Mechanistic analysis revealed that Vacq upregulated the expressions of pro‑apoptotic proteins [B‑cell lymphoma 2 (bcl‑2)‑associated X protein (Bax) and Bcl‑2‑like protein 11] and downregulated the pro‑survival protein, Bcl‑2, expression in HCC cells. Furthermore, Vacq induced Bax translocation. Of note, Vacq displayed inhibitory effects on patient‑derived HCC cells in two‑dimensional (2D) and three-dimensional (3D) cultures. Taken together, the data suggested that Vacq induced intrinsic apoptosis and may be utilized as an effective reagent for HCC treatment.

Tumor and circulating biomarkers in patients with second-line hepatocellular carcinoma from the randomized phase II study with tivantinib

ARQ 197-215 was a randomized placebo-controlled phase II study testing the MET inhibitor tivantinib in second-line hepatocellular carcinoma (HCC) patients. It identified tumor MET as a key biomarker in HCC.Aim of this research was to study the prognostic and predictive value of tumor (MET, the receptor tyrosine kinase encoded by the homonymous MNNG-HOS transforming gene) and circulating (MET, hepatocyte growth factor [HGF], alpha-fetoprotein [AFP], vascular endothelial growth factor [VEGF]) biomarkers in second-line HCC. Tumor MET-High status was centrally assessed by immunohistochemistry. Circulating biomarkers were centrally analyzed on serum samples collected at baseline and every 4-8 weeks, using medians as cut-off to determine High/Low status. Tumor MET, tested in 77 patients, was more frequently High after (82%) versus before (40%) sorafenib. A significant interaction (p = 0.04) between tivantinib and baseline tumor MET in terms of survival was observed. Baseline circulating MET and HGF (102 patients) High status correlated with shorter survival (HR 0.61, p = 0.03, and HR 0.60, p = 0.02, respectively), while the association between AFP (104 patients) or VEGF (103 patients) status and survival was non-significant.

CONCLUSIONS

Tumor MET levels were higher in patients treated with sorafenib. Circulating biomarkers such as MET and HGF may be prognostic in second-line HCC. These results need to be confirmed in larger randomized clinical trials.

Co-targeting of DNA, RNA, and protein molecules provides optimal outcomes for treating osteosarcoma and pulmonary metastasis in spontaneous and experimental metastasis mouse models

Metastasis is a major cause of mortality for cancer patients and remains as the greatest challenge in cancer therapy. Driven by multiple factors, metastasis may not be controlled by the inhibition of single target. This study was aimed at assessing the hypothesis that drugs could be rationally combined to co-target critical DNA, RNA and protein molecules to achieve saturation attack against metastasis. Independent actions of the model drugs DNA-intercalating doxorubicin, RNA-interfering miR-34a and protein-inhibiting sorafenib on DNA replication, RNA translation and protein kinase signaling in highly metastatic, human osteosarcoma 143B cells were demonstrated by the increase of? H2A.X foci formation, reduction of c-MET expression and inhibition of Erk1/2 phosphorylation, respectively, and optimal effects were found for triple-drug combination. Consequently, triple-drug treatment showed a strong synergism in suppressing 143B cell proliferation and the greatest effects in reducing cell invasion. Compared to single- and dual-drug treatment, triple-drug therapy suppressed pulmonary metastases and orthotopic osteosarcoma progression to significantly greater degrees in orthotopic osteosarcoma xenograft/spontaneous metastases mouse models, while none showed significant toxicity. In addition, triple-drug therapy improved the overall survival to the greatest extent in experimental metastases mouse models. These findings demonstrate co-targeting of DNA, RNA and protein molecules as a novel therapeutic strategy for the treatment of metastasis.

Serine peptidase inhibitor Kunitz type 2 (SPINT2) in cancer development and progression

Understanding the molecular basis and mechanisms involved in neoplastic transformation and progression is important for the development of novel selective target therapeutic strategies. Hepatocyte growth factor (HGF)/c-MET signaling plays an important role in cell proliferation, survival, migration and motility of cancer cells. Serine peptidase inhibitor Kunitz type 2 (SPINT2) binds to and inactivates the HGF activator (HGFA), behaving as an HGFA inhibitor (HAI) and impairing the conversion of pro-HGF into bioactive HGF. The scope of the present review is to recapitulate and review the evidence of SPINT2 participation in cancer development and progression, exploring the clinical, biological and functional descriptions of the involvement of this protein in diverse neoplasias. Most studies are in agreement as to the belief that, in a large range of human cancers, the SPINT2 gene promoter is frequently methylated, resulting in the epigenetic silence of this gene. Functional assays indicate that SPINT2 reactivation ameliorates the malignant phenotype, specifically reducing cell viability, migration and invasion in diverse cancer cell lines. In sum, the SPINT2 gene is epigenetically silenced or downregulated in human cancers, altering the balance of HGF activation/inhibition ratio, which contributes to cancer development and progression.

How does the tumor microenvironment play a role in hepatobiliary tumors?

The tumor microenvironment (TME) is defined as the structural and dynamic network of cellular and non-cellular interactions between malignant cells and the surrounding non-malignant matrix. Hepatocellular carcinoma (HCC) and pancreatic ductal adenocarcinoma (PDAC) are two of the most challenging gastrointestinal malignancies. Despite clinical advancements in understanding tumor biology and growth of the chemotherapeutic industry, there have been no corresponding improvements in prognosis and overall survival of HCC and PDAC. Both of these cancers have a very intimate relationship with their surrounding environment; the TME is thought to actively participate in initiating and sustaining these malignancies. Individual TME constituents play a vital role in chemoresistance and recurrence after surgery and have been established as independent prognostic factors. This review article will highlight the diverse structural components, key signaling pathways, and extracellular matrices of HCC and PDAC and discuss their crosstalk with tumor cells to promote growth and metastasis. The article will also summarize the latest laboratory and clinical research based on therapeutic targets identified within the TME of both HCC and PDAC.

Effect of the Wnt/β-catenin signaling pathway on apoptosis, migration, and invasion of transplanted hepatocellular carcinoma cells after transcatheter arterial chemoembolization in rats

This study aims to investigate the influence of the Wnt/β-catenin signaling pathway on apoptosis, migration, and invasion of transplanted hepatocellular carcinoma (HCC) cells after transcatheter arterial chemoembolization (TACE) in rat models. A total of 80 rats were grouped into sham, TACE, Wnt-C59, and TACE + Wnt-C59 groups (n = 20). Ten days after model establishment, 10 rats in each group were executed to perform pathological examination and follow-up experiment, and the remaining 10 rats in each group were reared to observe the survival condition. RT-qPCR and Western blotting were applied to determine the expressions of Wnt1, β-catenin, cyclin D1, c-met, vimentin, E-cadherin, and vascular endothelial growth factor (VEGF). ELISA was performed to measure the serum alpha-fetoprotein (AFP) content of rats. Flow cytometry was used to evaluate cell apoptosis rate and transwell assay to examine cell migration and invasion. Compared with the TACE group, the Wnt-C59 and TACE + Wnt-C59 groups showed increased apoptosis and survival time (the TACE + Wnt-C59 group > the Wnt-C59 group). Compared with the sham group, the TACE + Wnt-C59 groups showed decreased cancer tissue weight and expressions of Wnt1, β-catenin, cyclin D1, vimentin, c-met, and VEGF, but increased E-cadherin expression. Compared with the TACE group, the Wnt-C59 and TACE + Wnt-C59 groups showed decreased AFP level, migration, and invasion (the TACE + Wnt-C59 group < the Wnt-C59 group). These findings indicate inhibition of the Wnt/β-catenin signaling pathway improves therapeutic effect on TACE via suppressing migration, invasion, and promoting apoptosis of transplanted HCC cells in rats.

Cabozantinib in hepatocellular carcinoma: results of a phase 2 placebo-controlled randomized discontinuation study

Background

Cabozantinib, an orally bioavailable inhibitor of tyrosine kinases including MET, AXL, and VEGF receptors, was assessed in patients with hepatocellular carcinoma (HCC) as part of a phase 2 randomized discontinuation trial with nine tumor-type cohorts.

Patients and methods

Eligible patients had Child-Pugh A liver function and ≤1 prior systemic anticancer regimen, completed ≥4 weeks before study entry. The cabozantinib starting dose was 100 mg daily. After an initial 12-week cabozantinib treatment period, patients with stable disease (SD) per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.0 were randomized to cabozantinib or placebo. The primary endpoint of the lead-in stage was objective response rate (ORR) at week 12, and the primary endpoint of the randomized stage was progression-free survival (PFS).

Results

Among the 41 HCC patients enrolled, the week 12 ORR was 5%, with 2 patients achieving a confirmed partial response (PR). The week 12 disease control rate (PR or SD) was 66% (Asian subgroup: 73%). Of patients with ≥1 post-baseline scan, 78% had tumor regression, with no apparent relationship to prior sorafenib therapy. Alpha-fetoprotein (AFP) response (>50% reduction from baseline) occurred in 9 of the 26 (35%) patients with elevated baseline AFP and ≥1 post-baseline measurement. Twenty-two patients with SD at week 12 were randomized. Median PFS after randomization was 2.5 months with cabozantinib and 1.4 months with placebo, although this difference was not statistically significant. Median PFS and overall survival from Day 1 in all patients were 5.2 and 11.5 months, respectively. The most common grade 3/4 adverse events, regardless of attribution, were diarrhea (20%), hand-foot syndrome (15%), and thrombocytopenia (15%). Dose reductions were utilized in 59% of patients.

Conclusions

Cabozantinib has clinical activity in HCC patients, including objective tumor responses, disease stabilization, and reductions in AFP. Adverse events were managed with dose reductions.

Trial registration number

NCT00940225.

Targeting multiple oncogenic pathways for the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common forms of liver cancer diagnosed worldwide. HCC occurs due to chronic liver disease and is often diagnosed at advanced stages. Chemotherapeutic agents such as doxorubicin are currently used as first-line agents for HCC therapy, but these are non-selective cytotoxic molecules with significant side effects. Sorafenib, a multi-targeted tyrosine kinase inhibitor, is the only approved targeted drug for HCC patients. However, due to adverse side effects and limited efficacy, there is a need for the identification of novel pharmacological drugs beyond sorafenib. Several agents that target and inhibit various signaling pathways involved in HCC are currently being assessed for HCC treatment. In the present review article, we summarize the diverse signal transduction pathways responsible for initiation as well as progression of HCC and also the potential anticancer effects of selected targeted therapies that can be employed for HCC therapy.

Activation of Focal Adhesion Kinase and Src Mediates Acquired Sorafenib Resistance in A549 Human Lung Adenocarcinoma Xenografts

Despite encouraging clinical results with sorafenib monotherapy in patients with KRAS-mutant non-small-cell lung cancer (NSCLC), the overall survival benefit of this drug is limited by the inevitable development of acquired resistance. The exact mechanism underlying acquired sorafenib resistance in KRAS-mutant NSCLC is unclear. In this study, the mechanism of acquired sorafenib resistance was explored using a biologically relevant xenograft model, which was established by using the A549 human lung adenocarcinoma cell line and an in vivo-derived, sorafenib-resistant A549 subline (A549/SRFres). Results from the initial study demonstrated that sorafenib treatment significantly decreased E-cadherin (P < 0.05) levels but significantly increased matrix metallopeptidase 9 (MMP9) levels (P < 0.01) in A549/SRFres tumors, whereas expression levels of phospho-protein kinase B (AKT), phospho-focal adhesion kinase (FAK), and phospho-Src were elevated in sorafenib-treated A549 and A549/SRFres tumors. We next examined whether concomitant dasatinib treatment could overcome acquired sorafenib resistance by blocking the FAK/Src escape route that mediates resistance. Despite the observed in vitro synergy between sorafenib and dasatinib, the in vivo antitumor effect of half-dose sorafenib-dasatinib combination therapy was inferior to that of the full-dose sorafenib treatment. Although the sorafenib-dasatinib combination effectively inhibited Src and AKT phosphorylation, it did not block the Y576/577-FAK phosphorylation, nor did it decrease vimentin protein expression; unexpectedly, it increased Y397-FAK phosphorylation and MMP9 protein expression in tumors. These results suggest that acquired sorafenib resistance in KRAS-mutant A549 xenografts involves the compensatory activation of FAK and Src, and Src inhibition alone is insufficient to diminish sorafenib-promoted epithelial-mesenchymal transition process and invasive potentials in tumors.

Secreted GRP78 activates EGFR-SRC-STAT3 signaling and confers the resistance to sorafeinib in HCC cells

Acquired resistance is a common phenomenon for HCC patients who undergone sorafenib treatment, however the mechanism by which acquired resistance develops remains elusive. In this study, we found that GRP78 could be detected in the serum samples of HCC patients and the conditional medium of multiple HCC cell lines, suggesting that GRP78 is secreted by HCC cells. Further studies showed that secreted GRP78 facilitated the proliferation and inhibited the apoptosis induced by sorafenib both in HCC cell lines and in tumor xenografts. We further found that secreted GRP78 could interact physically with EGFR, therefore activates EGFR signaling pathway. knockdown of EGFR decreased secreted GRP78 induced phosphorylation of SRC and STAT3. By contrast, overexpression of EGFR further enhanced the phosphorylation of SRC and STAT3 induced by secreted GRP78, suggesting the critical role of EGFR in secreted GRP78 conferred resistance to sorafeinib. Moreover, inhibition of SRC by PP2 antagonized the resistance to sorafenib and inhibited the activation of STAT3 conferred by secreted GRP78. Taken together, our results showed that secreted GRP78 could interact with EGFR, activate EGFR-SRC-STAT3 signaling, conferring the resistance to sorafenib.

Lenalidomide as second-line therapy for advanced hepatocellular carcinoma: exploration of biomarkers for treatment efficacy

BACKGROUND

Lenalidomide has immunomodulatory and anti-angiogenic effects and showed moderate anti-tumour efficacy in patients with. advanced hepatocellular carcinoma (HCC) AIM: To explore potential biomarkers of lenalidomide efficacy as second-line therapy for HCC.

METHODS

Eligible patients were diagnosed with advanced HCC, documented progression on sorafenib, and Child-Pugh class A liver function. Patients received 25 mg/day lenalidomide orally on days 1-21 every 4 weeks. The primary endpoint was 6 month progression-free survival rate. Early α-fetoprotein response was defined as a > 20% decline of α-fetoprotein levels from baseline within the first 4 weeks of treatment. Vascular response, evaluated using dynamic contrast-enhanced magnetic resonance imaging, was defined as a > 40% decline in K^trans after 2 weeks of treatment. The percentage of peripheral blood lymphocyte subsets were also analysed.

RESULTS

Fifty-five patients were enrolled. The response rate was 13%, and the disease-control rate was 53%. The 6 month progression-free survival rate was 9.1%. The median progression-free and overall survival was 1.8 months and 8.9 months respectively. Early α-fetoprotein response was significantly associated with higher disease-control rate (76% vs 22%, P = .001) and longer progression-free survival (P = .020). Vascular response was not associated with any treatment outcomes. Patients with a high pre-treatment B cell percentage were more likely to have disease control (70% vs 36%, P = .010) and exhibited longer progression-free survival (P < .001) and overall survival (P = .042).

CONCLUSIONS

Lenalidomide exhibited moderate activity as second-line therapy for advanced HCC. Its immunomodulatory effects should be further explored (www.clinicaltrials.gov NCT01545804).

Serum and tissue markers in hepatocellular carcinoma and cholangiocarcinoma: clinical and prognostic implications

HCC represents the sixth most common cancer worldwide and the second leading cause of cancer-related death. Despite the high incidence, treatment options for advanced HCC remain limited and unsuccessful, resulting in a poor prognosis. Despite the major advances achieved in the diagnostic management of HCC, only one third of the newly diagnosed patients are presently eligible for curative treatments. Advances in technology and an increased understanding of HCC biology have led to the discovery of novel biomarkers. Improving our knowledge about serum and tissutal markers could ultimately lead to an early diagnosis and better and early treatment strategies for this deadly disease. Serum biomarkers are striking potential tools for surveillance and early diagnosis of HCC thanks to the non-invasive, objective, and reproducible assessments they potentially enable. To date, many biomarkers have been proposed in the diagnosis of HCC. Cholangiocarcinoma (CCA) is an aggressive malignancy, characterized by early lymph node involvement and distant metastasis, with 5-year survival rates of 5%-10%. The identification of new biomarkers with diagnostic, prognostic or predictive value is especially important as resection (by surgery or combined with a liver transplant) has shown promising results and novel therapies are emerging. However, the relatively low incidence of CCA, high frequency of co-existing cholestasis or cholangitis (primary sclerosing cholangitis –PSC- above all), and difficulties with obtaining adequate samples, despite advances in sampling techniques and in endoscopic visualization of the bile ducts, have complicated the search for accurate biomarkers. In this review, we attempt to analyze the existing literature on this argument.

Stathmin decreases cholangiocarcinoma cell line sensitivity to staurosporine-triggered apoptosis via the induction of ERK and Akt signaling

Cholangiocarcinoma is a rare, but highly fatal malignancy. However, the intrinsic mechanism involved in its tumorigenesis remains obscure. An urgent need remains for a promising target for cholangiocarcinoma biological therapies. Based on comparative proteomical technologies, we found 253 and 231 different spots in gallbladder tumor cell lines and cholangiocarcinoma cell lines, respectively, relative to non-malignant cells. Using Mass Spectrometry (MS) and database searching, we chose seven differentially expressed proteins. High Stathmin expression was found in both cholangiocarcinoma and gallbladder carcinoma cells. Stathmin expression was validated using immunohistochemistry and western blot in cholangiocarcinoma tissue samples and peritumoral tissue. It was further revealed that high Stathmin expression was associated with the repression of staurosporine-induced apoptosis in the cholangiocarcinoma cell. Moreover, we found that Stathmin promoted cancer cell proliferation and inhibited its apoptosis through protein kinase B (Akt) and extracellular signal-regulated kinase (ERK) signaling. Integrin, β1 appears to serve as a partner of Stathmin induction of ERK and Akt signaling by inhibiting apoptosis in the cholangiocarcinoma cell. Understanding the regulation of anti-apoptosis effect by Stathmin might provide new insight into how to overcome therapeutic resistance in cholangiocarcinoma.

Ganoderic acid A inhibits proliferation and invasion, and promotes apoptosis in human hepatocellular carcinoma cells

Ganoderic acid A (GA-A), a triterpenoid, has been demonstrated to suppress cell proliferation in various cancers, including breast cancer and osteosarcoma. However, its effect on human hepatocellular carcinoma (HCC) remains to be elucidated. The present study aimed to investigate the effect of GA-A on HCC cells in vitro. The HepG2 and SMMC7721 human HCC cell lines were treated with differing concentrations of GA-A for 24, 48 and 72 h. The cell growth rate, cell cycle and apoptosis, migration and invasion were determined using a Cell Counting Kit-8, flow cytometry and transwell assays, respectively. The expression of apoptosis-associated proteins was detected via western blot analysis. GA-A significantly inhibited the proliferation of human HCC HepG2 and SMMC7721 cells in a dose-dependent manner. Furthermore, GA-A induced cell cycle arrest at the G0/G1 phase and apoptosis, and suppressed the migration and invasion of HCC cells. Furthermore, GA-A decreased the expression of cyclin D1 and increased the expression of p21 and cleaved caspase-3. In conclusion, GA-A suppressed the proliferation of human HCC cells in vitro and may act as a promising natural therapeutic reagent in the treatment of HCC.

The Therapeutic Targeting of HGF/c-Met Signaling in Hepatocellular Carcinoma: Alternative Approaches

The poor prognosis of hepatocellular carcinoma (HCC), one of the most devastating cancers worldwide, is due to frequent recurrence and metastasis. Among the metastatic factors in the tumor microenvironment, hepatocyte growth factor (HGF) has been well known to play critical roles in tumor progression, including HCC. Therefore, c-Met is now regarded as the most promising therapeutic target for the treatment of HCC. However, there are still concerns about resistance and the side effects of using conventional inhibitors of c-Met, such as tyrosine kinase inhibitors. Recently, many alternative strategies of c-Met targeting have been emerging. These include targeting the downstream effectors of c-Met, such as hydrogen peroxide-inducible clone 5 (Hic-5), to block the reactive oxygen species (ROS)-mediated signaling for HCC progression. Also, inhibition of endosomal regulators, such as PKCε and GGA3, may perturb the c-Met endosomal signaling for HCC cell migration. On the other hand, many herbal antagonists of c-Met-dependent signaling, such as saponin, resveratrol, and LZ-8, were identified. Taken together, it can be anticipated that more effective and safer c-Met targeting strategies for preventing HCC progression can be established in the future.

Dual inhibition of Akt and c-Met as a second-line therapy following acquired resistance to sorafenib in hepatocellular carcinoma cells

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.

Egr-1 regulates irradiation-induced autophagy through Atg4B to promote radioresistance in hepatocellular carcinoma cells

Although hepatocellular carcinoma (HCC) is usually response to radiation therapy, radioresistance is still the major obstacle that limits the efficacy of radiotherapy for HCC patients. Therefore, further investigation of underlying mechanisms in radioresistant HCC cells is warranted. In this study, we determined the effect of early growth response factor (Egr-1) on irradiation-induced autophagy and radioresistance in HCC cell lines SMMC-7721 and HepG2. We showed that autophagy-related gene 4B (Atg4B) is induced by Egr-1 upon ionizing radiation (IR) in HCC cells. Luciferase reporter assays and chromatin immunoprecipitation (ChIP) revealed that Egr-1 binds to the Atg4B promoter to upregulate its expression in HCC cells. Suppression of Egr-1 function by dominant-negative Egr-1 dampens IR-induced autophagy, cell migration, and increases cell sensitivity to radiotherapy. Together, these results suggest that Egr-1 contributes to HCC radioresistance through directly upregulating target gene Atg4B, which may serve as a protective mechanism by preferential activation of the autophagy.

The regulatory role of heparin on c-Met signaling in hepatocellular carcinoma cells

The role of heparin as an anticoagulant is well defined; however, its role in tumorigenesis and tumor progression is not clear yet. Some studies have shown that anticoagulant treatment in cancer patients improve overall survival, however, recent clinical trials have not shown a survival benefit in cancer patients receiving heparin treatment. In our previous studies we have shown the inhibitory effects of heparin on Hepatocyte Growth Factor (HGF)-induced invasion and migration in hepatocellular carcinoma (HCC) cells. In this study, we showed the differential effects of heparin on the behaviors of HCC cells based on the presence or absence of HGF. In the absence of HGF, heparin activated HGF/c-Met signaling and promoted motility and invasion in HCC cells. Heparin treatment led to c-Met receptor dimerization and activated c-Met signaling in an HGF independent manner. Heparin-induced c-Met activation increased migration and invasion through ERK1/2, early growth response factor 1 (EGR1) and Matrix Metalloproteinases (MMP) axis. Interestingly, heparin modestly decreased the proliferation of HCC cells by inhibiting activatory phosphorylation of Akt. The inhibition of c-Met signaling reversed heparin-induced increase in motility and invasion and, proliferation inhibition. Our study provides a new perspective into the role of heparin on c-Met signaling in HCC.

c-MET as a Potential Therapeutic Target in Ovarian Clear Cell Carcinoma

In this study, we investigated the therapeutic effects of c-MET inhibition in ovarian clear cell carcinoma (OCCC). Expression levels of c-MET in the epithelial ovarian cancers (EOCs) and normal ovarian tissues were evaluated using real-time PCR. To test the effects of c-MET inhibitors in OCCC cell lines, we performed MTT and apoptosis assays. We used Western blots to evaluate the expression of c-MET and its down-stream pathway. In vivo experiments were performed to test the effects of c-MET inhibitor on tumor growth in orthotopic mouse xenografts of OCCC cell line RMG1 and a patient-derived tumor xenograft (PDX) model of OCCC. c-MET expression was significantly greater in OCCCs compared with serous carcinomas and normal ovarian tissues (p < 0.001). In in vitro study, inhibition of c-MET using c-MET inhibitors (SU11274 or crizotinib) significantly decreased the proliferation, and increased the apoptosis of OCCC cells. SU11274 decreased expression of the p-c-MET proteins and blocked the phosphorylation of down-stream proteins Akt and Erk. Furthermore, SU11274 treatment significantly decreased the in vivo tumor weight in xenograft models of RMG1 cell and a PDX model for OCCC compared to control (p = 0.004 and p = 0.009, respectively).

Integrative biomarker analyses indicate etiological variations in hepatocellular carcinoma

BACKGROUND & AIMS

The purpose of this study was to determine whether biomarkers from baseline plasma and archival tissue specimens collected from patients enrolled in the EVOLVE-1 trial - a randomized phase 3 study of everolimus in hepatocellular carcinoma (HCC) - were associated with prognosis, etiology or ethnicity.

METHODS

Circulating plasma levels of bFGF, PLGF, VEGF, VEGF-D, c-Kit, collagen IV, sVEGFR1 and VEGFR2 were measured by ELISA (N=503). Protein levels of IGF-1R, c-Met, mTOR, Tsc2 were assayed by immunohistochemistry (N=125). Genomic DNA sequencing was conducted on a panel of 287 cancer-related genes (N=69).

RESULTS

Patients with baseline plasma concentrations of VEGF or sVEGFR1 above the cohort median had significantly shorter overall survival. These plasma biomarkers retained prognostic significance in a multivariate Cox regression model with geographic region, macroscopic vascular invasion and alpha fetoprotein AFP levels. Membranous c-Met protein levels were significantly lower for Asian patients, as well as for hepatitis B viral etiology. The prevalence of genetic changes were similar to previous reports, along with a trend towards higher PTEN and TSC2 mutations among Asians.

CONCLUSIONS

The angiogenesis biomarkers VEGF and sVEGFR1 were independent prognostic predictors of survival in patients with advanced HCC. Potential differences in c-Met and mTOR pathway activation between Asian and non-Asian patients should be considered in future clinical trials.

LAY SUMMARY

Our study demonstrates that circulating angiogenesis biomarkers can predict the survival outcome in patients with advanced hepatocellular carcinoma independent of the clinical variables. There is etiology and ethnicity variation in molecular pathway activation in hepatocellular carcinoma, which should be considered for future clinical trial design of targeted therapy.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01035229.

Effect of adipocyte-secreted factors on EpCAM+/CD133+ hepatic stem cell population

Recent epidemiological studies have associated obesity with a variety of cancer types including HCC. However, the tumor initiating role of obesity in hepatocarcinogenesis is still unknown. The objective of this paper is to investigate the effect of adipocyte-secreted factors on EpCAM+/CD133+ cancer stem cells and to identify which factors play a role in modulating hepatic cancer stem cell behavior. Our results demonstrated that adipocyte-secreted factors affect motility and drug resistance of EpCAM+/CD133+ cells. When incubated with adipocyte conditioned media, EpCAM+/CD133+ cells exhibited augmented motility and reduced sorafenib-induced apoptosis. Using array-based system, we identified secretion of several cytokines such as IL6, IL8 and MCP1 by cultured adipocytes and activation of c-Met, STAT3 and ERK1/2 signaling pathways in EpCAM+/CD133+ cells incubated with adipocyte conditioned media. Treating EpCAM+/CD133+ cancer stem cells with IL6 receptor blocking antibody or c-Met inhibitor SU11274 both reduced the increase in motility; however SU11274 had greater effect on relieving protection from sorafenib-induced apoptosis. These results indicate that adipocyte-secreted factors might regulate cancer stem cell behavior through several signaling molecules including c-Met, STAT3 and ERK1/2 and inhibition of these signaling pathways offer novel strategies in targeting the effect of adipose-derived cytokines in cancer.

Elevated hepatocyte growth factor expression as an autocrine c-Met activation mechanism in acquired resistance to sorafenib in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and the third leading cause of cancer‐related deaths worldwide. Limitations in HCC treatment result due to poor prognosis and resistance against traditional radiotherapy and chemotherapies. The multikinase inhibitor sorafenib is the only FDA approved drug available for advanced HCC patients, and development of second‐line treatment options for patients who cannot tolerate or develop resistance to sorafenib is an urgent medical need. In this study, we established sorafenib‐resistant cells from Huh7 and Mahlavu cell lines by long‐term sorafenib exposure. Sorafenib‐resistant HCC cells acquired spindle‐shape morphology, upregulated mesenchymal markers, and showed significant increase in both migration and invasion abilities compared to their parental counterparts. Moreover, after long‐term sorafenib treatment, HCC cells showed induction of hepatocyte growth factor (HGF) synthesis and secretion along with increased levels of c‐Met kinase and its active phosphorylated form, indicating autocrine activation of HGF/c‐Met signaling. Importantly, the combined treatment of the resistant cells with c‐Met kinase inhibitor SU11274 and HGF neutralizing antibody significantly reversed the increased invasion ability of the cells. The combined treatment also significantly augmented sorafenib‐induced apoptosis, suggesting restoration of sorafenib sensitivity. These results describe, for the first time, compensatory upregulation of HGF synthesis leading to autocrine activation of HGF/c‐Met signaling as a novel cellular strategy in the acquisition of sorafenib resistance. Therefore, we suggest that combinatorial therapeutic strategies with HGF and c‐Met inhibitors comprise promising candidates for overcoming sorafenib resistance.