Sorafenib in liver cancer

Polyphyllin I induced ferroptosis to suppress the progression of hepatocellular carcinoma through activation of the mitochondrial dysfunction via Nrf2/HO-1/GPX4 axis

BACKGROUND

Ferroptosis is an emerging iron-dependent programmed cell death mode characterized by lipid peroxidation and iron accumulation, closely associated with Hepatocellular Carcinoma (HCC) progression. Although the impact of Polyphyllin I (PPI), a prominent bioactive constituent derived from Paris polyphylla, on diverse malignancies has been established, the specific role and potential mechanistic pathways through which PPI modulates ferroptosis in HCC remain elusive.

PURPOSE

This study aimed to elucidate the anti-cancer properties and potential mechanisms of PPI in inducing ferroptosis and triggering mitochondrial injury in HCC.

METHODS

Cell viability was assessed using CCK-8 assays. EdU proliferation and colony formation assays were employed to evaluate cell proliferation. A wound-healing assay was performed to assess cell migration. Transwell assay was utilized to evaluate cell invasion. Ferroptosis was evaluated through the utilization of a FerroOrange fluorescent probe, malondialdehyde (MDA) and reduced glutathione (GSH) assay kits, DCFH-DA fluorescent probe, western blotting, and transmission electron microscopy (TEM) analysis. Molecular docking, immunofluorescence, and western blotting were employed to predict and validate the binding and interaction of PPI with Nrf2, HO-1, xCT, and GPX4. Mitochondrial structure and membrane potential changes were evaluated using JC-1 and Mito Tracker Green fluorescent probes. A nude mice xenograft model was constructed to determine the inhibitory effects and the levels of ferroptosis of PPI on HCC through hematoxylin and eosin (H&E), Prussian blue reaction, immunofluorescence staining, immunohistochemistry, and western blotting analysis, in vivo.

RESULTS

PPI exhibited dose-dependent inhibitory effects on the proliferation, invasion, and metastasis of HCC cells mediated by increasing reactive oxygen species (ROS) and MDA levels, promoting Fe2+ accumulation, depleting GSH, and suppressing the expression of xCT and GPX4, thereby inducing ferroptosis in HCC. The induction of ferroptosis by PPI was associated with the binding of PPI to Nrf2, HO-1, and GPX4 proteins, modulating the Nrf2/HO-1/GPX4 antioxidant axis. PPI also induced mitochondrial structural damage and decreased mitochondrial membrane potential (MMP). Inhibition of ferroptosis by ferrostatin-1 (Fer-1) mitigated the mitochondrial disruption induced by PPI. In vivo, PPI inhibited Nrf2/HO-1/GPX4 axis-induced ferroptosis, impeding HCC growth similar to the effects of sorafenib.

CONCLUSION

These results demonstrated that PPI intervention can suppress the proliferation, invasion, and metastasis of HCC cells by enhancing mitochondrial disruption and inducing ferroptosis via the Nrf2/HO-1/GPX4 axis. Consequently, our research advances the frontiers of pharmacodynamics and deepens our comprehension of the intricate mechanisms underpinning PPI. Furthermore, it has yielded an innovative treatment stratagem rooted in the tenets of Traditional Chinese Medicine (TCM), thereby furnishing a novel therapeutic avenue for addressing HCC.

Design, synthesis, and antitumor screening of new thiazole, thiazolopyrimidine, and thiazolotriazine derivatives as potent inhibitors of VEGFR-2

New thiazole, thiazolopyrimidine, and thiazolotriazine derivatives 3-12 and 14a-f were synthesized. The newly synthesized analogs were tested for in vitro antitumor activity against HepG2, HCT-116, MCF-7, HeP-2, and Hela cancer cells. Results indicated that compound 5 displayed the highest potency toward the tested cancer cells. Compound 11b possessed enhanced effectiveness over MCF-7, HepG2, HCT-116, and Hela cancer cells. In addition, compounds 4 and 6 showed promising activity toward HCT-116, MCF-7, and Hela cancer cells and eminent activity against HepG2 and HeP-2 cells. Moreover, compounds 3-6 and 11b were tested for their capability to inhibit vascular endothelial growth factor receptor-2 (VEGFR-2) activity. The obtained results showed that compound 5 displayed significant inhibitory activity against VEGFR-2 (half-maximal inhibitory concentration [IC50 ] = 0.044 μM) comparable to sunitinib (IC50  = 0.100 μM). Also, the synthesized compounds 3-6 and 11b were subjected to in vitro cytotoxicity tests over WI38 and WISH normal cells. It was found that the five tested compounds displayed significantly lower cytotoxicity than doxorubicin toward normal cell lines. Cell cycle analysis proved that compound 5 induces cell cycle arrest in the S phase for HCT-116 and Hela cancer cell lines and in the G2/M phase for the MCF-7 cancer cell line. Moreover, compound 5 induced cancer cell death through apoptosis accompanied by a high ratio of BAX/BCL-2 in the screened cancer cells. Furthermore, docking results revealed that compound 5 showed the essential interaction bonds with VEGFR-2, which agreed with in vitro enzyme assay results. In silico studies showed that most of the analyzed compounds complied with the requirements of good oral bioavailability with minimal toxicity threats in humans.

New theobromine derivatives inhibiting VEGFR-2: design, synthesis, antiproliferative, docking and molecular dynamics simulations

Background: VEGFR-2 is one of the most effective targets in cancer treatment. Aim: The design and semi-synthesis of new theobromine derivatives as potential VEGFR-2 inhibitors. Methods: In vitro and in silico evaluation of the synthesized compounds. Results: Compound 5b demonstrated excellent antiproliferative and VEGFR-2 inhibitory effects with significant apoptotic activity. It modulated the immune response by increasing IL-2 and reducing TNF-α levels. Docking and molecular dynamics simulations revealed the compound's binding affinity with VEGFR-2. Lastly, computational absorption, distribution, metabolism, excretion and toxicity studies indicated the high potential of compound 5b for drug development. Conclusion: Compound 5b could be a promising anticancer agent targeting VEGFR-2.

Long Noncoding RNA XIST Promotes Resistance to Lenvatinib in Hepatocellular Carcinoma Cells via Epigenetic Inhibition of NOD2

Background. Hepatocellular carcinoma (HCC) is a severe global health issue that still lacks of effective treatments. Lenvatinib is a novel tyrosine kinase inhibitor (TKI) that has been approved for the treatment of HCC. However, drug resistance is inevitable and limits the clinical application of lenvatinib. Till now, there is still little knowledge about the mechanisms under the resistance to lenvatinib in HCC. Long noncoding RNA (lncRNA) is a group of noncoding RNAs that play essential roles in various physiological activities including the chemoresistance. In the present study, through RNA sequencing, we discovered that lncRNA XIST was upregulated in HCC cells that was insensitive to lenvatinib. Mechanically, we found that lncXIST promotes lenvatinib resistance via activation of EZH2-NOD2-ERK axis in HCC cells. Our data suggest that targeting lncXIST/EZH2/NOD2/ERK axis might be a promising strategy to enhance the efficacy of lenvatinib against HCC cells.

Augmented Efficacy of Uttroside B over Sorafenib in a Murine Model of Human Hepatocellular Carcinoma

We previously reported the remarkable potency of uttroside B (Utt-B), saponin-isolated and characterized in our lab from Solanum nigrum Linn, against HCC. Recently, the U.S. FDA approved Utt-B as an ‘orphan drug’ against HCC. The current study validates the superior anti-HCC efficacy of Utt-B over sorafenib, the first-line treatment option against HCC. The therapeutic efficacies of Utt-B vs. sorafenib against HCC were compared in vitro, using various liver cancer cell lines and in vivo, utilizing NOD.CB17-Prkdcscid/J mice bearing human HCC xenografts. Our data indicate that Utt-B holds an augmented anti-HCC efficacy over sorafenib. Our previous report demonstrated the pharmacological safety of Utt-B in Chang Liver, the normal immortalized hepatocytes, and in the acute and chronic toxicity murine models even at elevated Utt-B concentrations. Here, we show that higher concentrations of sorafenib induce severe toxicity, in Chang Liver, as well as in acute and chronic in vivo models, indicating that, apart from the superior therapeutic benefit over sorafenib, Utt-B is a pharmacologically safer molecule, and the drug-induced undesirable effects can, thus, be substantially alleviated in the context of HCC chemotherapy. Clinical studies in HCC patients utilizing Utt-B, is a contiguous key step to promote this drug to the clinic.

CT-707 overcomes hypoxia-mediated sorafenib resistance in Hepatocellular carcinoma by inhibiting YAP signaling

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Sorafenib is the first-line treatment for advanced HCC, but the anti-cancer effects remain to be improved as indicated by its low response rates and failure to prolong the progression-free survival (PFS). Thus, it is urgent to explore approaches to improve the clinical outcome.

MATERIALS AND METHODS

The effect of Sorafenib in HCC was analyzed by SRB (sulforhodamine B) assay in normoxia and hypoxia, respectively. The different dose combination effect of CT707 and sorafenib was analyzed by SRB assay in hypoxia. Flow cytometry assay was used to detect the cell apoptosis rate with CT707 and sorafenib treatment in hypoxia. Western blotting was used to detect the expression levels of apoptosis -related proteins and the mechanism of CT707 overcome the resistance of sorafenib in hypoxia.

RESULTS

Our study showed that the characteristic intratumor hypoxia of advanced HCC is one of the major factors which mediated the drug resistance towards sorafenib in HCC. And CT-707, a novel multi-kinase inhibitor, could sensitize the hypoxic HCC cells towards sorafenib. Further studies showed that CT-707 abolished the nuclear translocation of Yes Associate-Protein (YAP), which has been demonstrated as one of mechanism of hypoxia-mediated sorafenib-resistance in HCC.

CONCLUSIONS

Overall, this study not only favors the development of this novel multi-kinase inhibitor CT-707 as a therapeutic agent against HCC, but also provides a potential strategy to overcome the hypoxia-mediated resistance to sorafenib in HCC patients.

An Overview on Single-Cell Technology for Hepatocellular Carcinoma Diagnosis

Hepatocellular carcinoma is a primary liver cancer caused by the accumulation of genetic mutation patterns associated with epidemiological conditions. This lethal malignancy exhibits tumor heterogeneity, which is considered as one of the main reasons for drug resistance development and failure of clinical trials. Recently, single-cell technology (SCT), a new advanced sequencing technique that analyzes every single cell in a tumor tissue specimen, aids complete insight into the genetic heterogeneity of cancer. This helps in identifying and assessing rare cell populations by analyzing the difference in gene expression pattern between individual cells of single biopsy tissue which normally cannot be identified from pooled cell gene expression pattern (traditional sequencing technique). Thus, SCT improves the clinical diagnosis, treatment, and prognosis of hepatocellular carcinoma as the limitations of other techniques impede this cancer research progression. Application of SCT at the genomic, transcriptomic, and epigenomic levels to promote individualized hepatocellular carcinoma diagnosis and therapy. The current review has been divided into ten sections. Herein we deliberated on the SCT, hepatocellular carcinoma diagnosis, tumor microenvironment analysis, single-cell genomic sequencing, single-cell transcriptomics, single-cell omics sequencing for biomarker development, identification of hepatocellular carcinoma origination and evolution, limitations, challenges, conclusions, and future perspectives.

Targeting VEGFR-2 by new quinoxaline derivatives: Design, synthesis, antiproliferative assay, apoptosis induction, and in silico studies

Twelve new triazolo[4,3-a]quinoxaline-based compounds are reported as anticancer agents with potential effects against vascular endothelial growth factor receptor-2 (VEGFR-2), using sorafenib as a reference molecule. With sorafenib as the positive control, the antiproliferative effects of the synthesized compounds against MCF-7 and HepG2 cells, as well as their VEGFR-2-inhibitory activities, were assessed. The most powerful VEGFR-2 inhibitor was compound 14a, which had an IC₅₀ value of 3.2 nM, which is very close to that of sorafenib (IC₅₀  = 3.12 nM). Furthermore, compounds 14c and 15d showed potential inhibitory activity against VEGFR-2, with IC₅₀ values of 4.8 and 5.4 nM, respectively. Compound 14a caused apoptosis in HepG2 cells and stopped the cell cycle at the G2/M phase. In HepG2 cells, it also increased the levels of the proteases caspase-3 and caspase-9, as well as the Bax/Bcl-2 ratio. In silico ADMET (absorption, distribution, metabolism, excretion, and toxicity) and toxicity experiments revealed that the synthesized agents had acceptable drug-likeness.

Therapeutic strtegies of glioblastoma (GBM): The current advances in the molecular targets and bioactive small molecule compounds

Glioblastoma (GBM) is the most common aggressive malignant tumor in brain neuroepithelial tumors and remains incurable. A variety of treatment options are currently being explored to improve patient survival, including small molecule inhibitors, viral therapies, cancer vaccines, and monoclonal antibodies. Among them, the unique advantages of small molecule inhibitors have made them a focus of attention in the drug discovery of glioblastoma. Currently, the most used chemotherapeutic agents are small molecule inhibitors that target key dysregulated signaling pathways in glioblastoma, including receptor tyrosine kinase, PI3K/AKT/mTOR pathway, DNA damage response, TP53 and cell cycle inhibitors. This review analyzes the therapeutic benefit and clinical development of novel small molecule inhibitors discovered as promising anti-glioblastoma agents by the related targets of these major pathways. Meanwhile, the recent advances in temozolomide resistance and drug combination are also reviewed. In the last part, due to the constant clinical failure of targeted therapies, this paper reviewed the research progress of other therapeutic methods for glioblastoma, to provide patients and readers with a more comprehensive understanding of the treatment landscape of glioblastoma.

Design, synthesis, docking, ADMET studies, and anticancer evaluation of new 3-methylquinoxaline derivatives as VEGFR-2 inhibitors and apoptosis inducers

Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a critical role in cancer angiogenesis. Inhibition of VEGFR-2 activity proved effective suppression of tumour propagation. Accordingly, two series of new 3-methylquinoxaline derivatives have been designed and synthesised as VEGFR-2 inhibitors. The synthesised derivatives were evaluated in vitro for their cytotoxic activities against MCF-7and HepG2 cell lines. In addition, the VEGFR-2 inhibitory activities of the target compounds were estimated to indicate the potential mechanism of their cytotoxicity. To a great extent, the results of VEGFR-2 inhibition were highly correlated with that of cytotoxicity. Compound 27a was the most potent VEGFR-2 inhibitor with IC50 of 3.2 nM very close to positive control sorafenib (IC50 = 3.12 nM). Such compound exhibited a strong cytotoxic effect against MCF-7 and HepG2, respectively with IC50 of 7.7 and 4.5 µM in comparison to sorafenib (IC50 = 3.51 and 2.17 µM). In addition, compounds 28, 30f, 30i, and 31b exhibited excellent VEGFR-2 inhibition activities (IC50 range from 4.2 to 6.1 nM) with promising cytotoxic activity. Cell cycle progression and apoptosis induction were investigated for the most active member 27a. Also, the effect of 27a on the level of caspase-3, caspase-9, and BAX/Bcl-2 ratio was determined. Molecular docking studies were implemented to interpret the binding mode of the target compounds with the VEGFR-2 pocket. Furthermore, toxicity and ADMET calculations were performed for the synthesised compounds to study their pharmacokinetic profiles.

Design, synthesis and molecular docking of new [1,2,4] triazolo[4,3-a]quinoxaline derivatives as anticancer agents targeting VEGFR-2 kinase

Vascular endothelial growth factor receptor-2 (VEGFR-2) is critically involved in cancer angiogenesis. Blocking of VEGFR-2 signaling pathway proved effective suppression of tumor growth. Accordingly, two series of new triazoloquinoxaline-based derivatives were designed and synthesized as VEGFR-2 inhibitors. All in vitro cytotoxic activities of the synthesized compounds were evaluated against two human cancer cell lines (MCF-7 and HepG2). To confirm the potential mechanism of cytotoxicity, enzymatic assays against VEGFR-2 were estimated for all the target compounds. The results of VEGFR-2 inhibitory activity and cytotoxicity were in high correlation. Compound 22a exhibited the highest cytotoxic effect with IC₅₀ values of 6.2 and 4.9 μM against MCF-7 and HepG2, respectively, comparing to sorafenib (IC₅₀ = 3.53 and 2.18 μM). Such derivative showed the best VEGFR-2 inhibitory activity with an IC₅₀ value of 3.9 nM, which is very close to that of sorafenib (IC₅₀ = 3.13 nM). Moreover, compounds 22b, 23b, and 23e exhibited strong cytotoxic activity with IC₅₀ values ranging from 11.7 to 15.3 μM. Also, these compounds showed promising VEGFR-2 inhibition with IC₅₀ values of 4.2, 5.7, and 4.7 nM, respectively. In silico docking, ADMET, and toxicity studies were carried out for the synthesized compounds. The results revealed that some compounds have a good binding mode against VEGFR-2 and a high level of drug-likeness.

Small molecules in targeted cancer therapy: advances, challenges, and future perspectives

Due to the advantages in efficacy and safety compared with traditional chemotherapy drugs, targeted therapeutic drugs have become mainstream cancer treatments. Since the first tyrosine kinase inhibitor imatinib was approved to enter the market by the US Food and Drug Administration (FDA) in 2001, an increasing number of small-molecule targeted drugs have been developed for the treatment of malignancies. By December 2020, 89 small-molecule targeted antitumor drugs have been approved by the US FDA and the National Medical Products Administration (NMPA) of China. Despite great progress, small-molecule targeted anti-cancer drugs still face many challenges, such as a low response rate and drug resistance. To better promote the development of targeted anti-cancer drugs, we conducted a comprehensive review of small-molecule targeted anti-cancer drugs according to the target classification. We present all the approved drugs as well as important drug candidates in clinical trials for each target, discuss the current challenges, and provide insights and perspectives for the research and development of anti-cancer drugs.

New bis([1,2,4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives as VEGFR-2 inhibitors and apoptosis inducers: Design, synthesis, in silico studies, and anticancer evaluation

A new series of bis([1,2,4]triazolo)[4,3-a:3',4'-c]quinoxaline derivatives were designed and synthesized to have the main essential pharmacophoric features of VEGFR-2 inhibitors. VEGFR-2 inhibitory activities were assessed for the designed compounds. In addition, cytotoxic activity was evaluated for all derivatives against two human cancer cell lines namely, HepG-2 and MCF-7. The most cytotoxic compound 20 h was subjected to further biological investigations including cell cycle, apoptosis, caspase-3, caspase-9, BAX, and Bcl-2 analyses. Different in silico studies as docking, ADMET and toxicity were carried out. The results exhibited that compounds 20b, 20e, 20h and20mshowed promising VEGFR-2 inhibitory activities with IC₅₀values of 5.7, 6.7, 3.2, and 3.1 µM, respectively. Moreover, these promising members exhibited the highest antiproliferative activities against the two cell lines with IC₅₀values ranging from 3.3 to 14.2 µM, comparing to sorafenib (IC₅₀ = 2.17 and 3.43 µM against HepG2 and MCF-7, respectively). Additionally, compound 20h induced cell cycle arrest of HepG2 cells at G2/M phase. Also, such compound increased the progress of apoptosis by 3.5-fold compared to the control. As well, compound 20h showed a significant increase in the level of caspase-3 (2.07-fold), caspase-9 (1.72-fold), and BAX (1.83-fold), and a significant decrease in Bcl-2 level (1.92-fold). The in silico studies revealed that the synthesized compounds have binding pattern like that of sorafenib.

Exploration of structural requirements for the inhibition of VEGFR-2 tyrosine kinase: Binding site analysis of type II, 'DFG-out' inhibitors

The conserved three-dimensional structure of receptor tyrosine kinases (RTKs) has been varyingly observed in prokaryotes to humans that actively participate in the phosphorylation process of tyrosine residues in the protein, which results in the alteration of protein's function. Mutation and transcriptional or post-translational modifications lead to a deregulation of kinases, which ultimately fallout into the development of pathological conditions like cancer. The human genome encodes two kinds of tyrosine kinases: non-receptor tyrosine kinases (NRTKs) and receptor tyrosine kinases (RTKs). Among these kinases, VEGF/VEGFR-2 signaling cascade is an important target to develop novel small-molecule inhibitors for the therapy of abnormal angiogenesis incorporated with cancer. Due to advances in the knowledge of the catalytic domain and 'DFG-motif' region, selective 'DFG-in' (type I) and 'DFG-out' (type II) VEGFR-2/KDR inhibitors were successfully developed, and some are in different phases of a clinical trial. 'DFG-out' (inactive) confirmation has significant advantages over 'DFG-in' (active) confirmation concerning the affinity of the ATP at the catalytic domain. Further, in the catalytic domain, between front and back cleft, smaller gatekeeper residue (Val916) present; therefore, selectivity against VEGFR-2 could be precisely achieved. In this review, small molecule type II/'DFG-out' inhibitors, their conformation, interaction at receptor binding pocket, and structural requirements to inhibit VEGFR-2 at the molecular level are discussed.HighlightsVEGFR-2 is a type of membrane-bound receptor tyrosine kinases (RTKs) that regulates the process of vasculogenesis and angiogenesis.Small molecule first-generation type I, 'DFG-in' and second-generation type II, 'DFG-out' VEGFR-2 inhibitors exhibit clinical benefits in the treatment of aberrant angiogenesis associated with cancer.Molecular docking of FDA approved and novel type II inhibitors were performed using X-ray crystal structures of VEGFR-2; binding site analysis was carried out.Structural requirements for the inhibition of VEGFR-2 were identified.

mTOR and ERK regulate VKORC1 expression in both hepatoma cells and hepatocytes which influence blood coagulation

Deficiency of γ-glutamyl carboxylation of coagulation factors, as evidenced by the elevated level of Des-γ-carboxyl prothrombin (DCP), is a common feature in hepatocellular carcinoma patients. Additionally, treatment of cancer patients with mTOR inhibitors significantly increases hemorrhagic events. However, the underlying mechanisms remain unknown. In the present study, Vitamin K epoxide reductase complex subunit 1 (VKORC1) was found to be significantly down-regulated in clinical hepatoma tissues and most tested hepatoma cell lines. In vitro investigations showed that VKORC1 expression was promoted by p-mTOR at the translational level and repressed by p-ERK at the transcriptional level. By exploring Hras12V transgenic mice, a hepatic tumor model, VKROC1 was significantly down-regulated in hepatic tumors and showed prolonged activated partial prothrombin time (APTT). In vivo investigations further showed that VKORC1 expression was promoted by p-mTOR and repressed by p-ERK in both hepatoma and hepatocytes. Consistently, APTT and prothrombin time were significantly prolonged under the mTOR inhibitor treatment and significantly shortened under the ERK inhibitor treatment. Conclusively, these findings indicate that mTOR and ERK play crucial roles in controlling VKORC1 expression in both hepatoma and hepatocytes, which provides a valuable molecular basis for preventing hemorrhage in clinical therapies.

Ceramide-Fabricated Co-Loaded Liposomes for the Synergistic Treatment of Hepatocellular Carcinoma

Combination therapy is one of the important methods to improve therapeutic effect on the treatment of hepatocellular carcinoma (HCC). Sorafenib (SF) is a canonical US Food and Drug Administration-approved multikinase molecule inhibitor against HCC. However, therapeutic benefit with Sorafenib alone was usually unsatisfactory. Ceramide (CE) is an endogenous bioactive sphingolipid, which has a strong potential to suppress various tumors. The combination of SF and CE was hoping to exert maximum synergistic antitumor effect through different tumor-suppressible mechanisms. In this respect, SF and CE co-loaded liposomes (SF/CE-liposomes) were developed to verify synergistic antitumor efficacy. The optimal molar ratio of SF and CE was determined through combination index. SF/CE-liposomes were prepared by thin-film hydration method, which exhibited spherical or ellipsoidal shape. Particle size of SF/CE-liposomes was 174 ± 4 nm with homogeneous distribution. Release profile of SF demonstrated that addition of CE imposed no significant impact on the release of SF. SF/CE-liposomes exhibited acceptable stability in different media and desirable storage stability over 30 days at 4°C. In vitro cellular uptake confirmed that SF/CE-liposomes could be efficiently internalized into HepG2 cells. In vitro cytotoxicity evaluation indicated that SF/CE-liposomes exhibited higher cytotoxicity on HepG2 cells. IC₅₀ value of SF/CE-liposomes was 11.5 ± 0.44 μM, which was significantly lower than that of SF-liposomes (^**p < 0.01). Evaluation of in vivo synergistic effect on H22-bearing mice verified that SF/CE-liposomes achieved robust antitumor activity in preventing tumor growth. All results suggested that SF/CE-liposomes might be served as an efficient co-delivery system for improving therapeutic efficacy of HCC.

Des-gamma-carboxy prothrombin antagonizes the effects of Sorafenib on human hepatocellular carcinoma through activation of the Raf/MEK/ERK and PI3K/Akt/mTOR signaling pathways

Despite significant progress, advanced hepatocellular carcinoma (HCC) remains an incurable disease, and the overall efficacy of targeted therapy by Sorafenib remains moderate. We hypothesized that DCP (des-gamma-carboxy prothrombin), a prothrombin precursor produced in HCC, might be one of the reasons linked to the low efficacy of Sorafenib. We evaluated the efficacy of Sorafenib in HLE and SK-Hep cells, both of which are known DCP-negative HCC cell lines. In the absence of DCP, Sorafenib effectively inhibited the growth of HCC and induced cancer cell apoptosis. In the presence of DCP, HCC was resistant to Sorafenib-induced inhibition and apoptosis, as determined by in vitro assays and in mice xenografted with HLE cells. Molecular analysis of HLE xenografted-nude mice showed that DCP activates the transduction of the Ras/Raf/MEK/ERK and Ras/PI3K/Akt/mTOR cascades. DCP might stimulate the formation of compensatory feedback loops in the intricately connected signaling pathways when kinases are targeted by Sorafenib. Our results indicate that DCP antagonizes the inhibitory effects of Sorafenib on HCC through activation of the Ras/Raf/MEK/ERK and Ras/PI3K/Akt/mTOR signaling pathways. Taken together, our findings define a DCP-mediated mechanism of inhibition of Sorafenib in HCC, which is critical for targeting therapy in advanced HCC.

Effect of TALEN-mediated IL-6 knockout on cell proliferation, apoptosis, invasion and anti-cancer therapy in hepatocellular carcinoma (HCC-LM3) cells

Purpose

To determine the exact effect of Interleukin-6 (IL-6) on tumor cell proliferation, apoptosis, invasion, and anti-cancer therapy in hepatocellular carcinoma (HCC).

Experimental Design

IL-6 was disrupted by transcription activator-like effector nucleases (TALEN) in HCCLM3 cells, and was used to evaluate the role of IL-6 on tumor cell proliferation, apoptosis, invasion and key signaling pathways involved in sorafenib and/or IFNα therapy.

Results

IL-6 has no direct effect on cell proliferation and invasion but promotes cell apoptosis and up-regulate IL-33 and VEGF-A expression. IL-6 could attenuate the anti-proliferation effect by sorafenib and combination therapy but facilitate the pro-apoptosis of the combination therapy and augment the pro-invasive effect induced by single treatment. IL-6 could down-regulate p-STAT3, however up-regulate the p-MEK/p-ERK and NF-kB/iNOS expression, and it also facilitated the promotion on p-JAK2 and p-MEK/p-ERK by either sorafenib or IFN-α. in vivo study, IL-6 significantly promotes tumor growth. The combination treatment showed the highest inhibition on tumor growth which is derived from HCCLM3-IL6(-) cells.

Conclusions

IL-6 has no direct effect on cell proliferation and invasion but promotes tumor cell apoptosis in vitro study. Sorafenib and combination therapies are suitable for HCC cells with low or no IL-6 expression confirmed in vivo study.

C2-ceramide enhances sorafenib-induced caspase-dependent apoptosis via PI3K/AKT/mTOR and Erk signaling pathways in HCC cells

Sorafenib as an effective multikinase inhibitor has been approved for the clinical treatment against advanced hepatocellular carcinoma (HCC). HCC treatment requires usually combined therapy because of its complex pathogenesis. Ceramide has been confirmed to induce remarkable apoptosis in human tumor cells and has attracted increasing attention in investigations on combination therapy. In this paper, the anti-HCC effect of sorafenib combined with C2-ceramide was investigated on cell vitality, apoptosis, and migration, and the underlying mechanism was examined using flow cytometry and western blot. Bel7402 cells coincubated with sorafenib and C2-ceramide exhibited lower cell vitality and more irregular cellular morphology and cell cycle arrest. Sorafenib plus C2-ceramide stimulated significantly the production of reactive oxygen species (ROS) and mitochondrial depolarization, which promoted caspases-dependent cell apoptosis as illustrated by related protein expression including caspase 3, caspase 9, Bax, Bcl-2, and cytochrome c. Combination treatment of sorafenib and C2-ceramide inhibited obviously cell growth and proliferation via PI3K/AKT/mTOR and Erk signaling pathways. Furthermore, the combination treatment was proved to inhibit cell migration and epithelial-mesenchymal transition (EMT). These findings indicated that the combination of C2-ceramide and sorafenib provided synergistic inhibitory effects on HCC cells.

Synthesis and Cytotoxic Activity of Biphenylurea Derivatives Containing Indolin-2-one Moieties

In our endeavor towards the development of potent anticancer agents, two different sets of biphenylurea-indolinone conjugates, 5a–s and 8a,b were synthesized. The in vitro cytotoxicity of the synthesized compounds was examined in two human cancer cell lines, namely MCF-7 breast cancer and PC-3 prostate cancer cells using the sulforhodamine B (SRB) colorimetric assay. In particular, the MCF-7 cancer cell line was more susceptible to the synthesized compounds. Compound 5o (IC₅₀ = 1.04 ± 0.10 μM) emerged as the most active member in this study against MCF-7, with 7-fold increased activity compared to the reference drug, doxorubicin (IC₅₀ = 7.30 ± 0.84 μM). Compounds 5l, 5q and 8b also exhibited superior cytotoxic activity against MCF-7 with IC₅₀ values of 1.93 ± 0.17, 3.87 ± 0.31 and 4.66 ± 0.42 μM, respectively. All of the tested compounds were filtered according to the Lipinski and Veber rules and all of them passed the filters. Additionally, several ADME descriptors for the synthesized compounds 5a–s and 8a,b were predicted via a theoretical kinetic study performed using the Discovery Studio 2.5 software.

Sorafenib-based combined molecule targeting in treatment of hepatocellular carcinoma

Sorafenib is the only and standard systematic chemotherapy drug for treatment of advanced hepatocellular carcinoma (HCC) at the current stage. Although sorafenib showed survival benefits in large randomized phase III studies, its clinical benefits remain modest and most often consist of temporary tumor stabilization, indicating that more effective first-line treatment regimens or second-line salvage therapies are required. The molecular pathogenesis of HCC is very complex, involving hyperactivated signal transduction pathways such as RAS/RAF/MEK/ERK and PI3K/AKT/mTOR and aberrant expression of molecules such as receptor tyrosine kinases and histone deacetylases. Simultaneous or sequential abrogation of these critical pathways or the functions of these key molecules involved in angiogenesis, proliferation, and apoptosis may yield major improvements in the management of HCC. In this review, we summarize the emerging sorafenib-based combined molecule targeting for HCC treatment and analyze the rationales of these combinations.

Berberine induces apoptosis by suppressing the arachidonic acid metabolic pathway in hepatocellular carcinoma

Berberine (BBR) has been suggested as a potential candidate anticancer agent due to its high anticancer activity and multiple mechanisms. In the present study, the inhibitory effect of BBR on hepatocellular carcinoma (HCC) via the suppression of the arachidonic acid (AA) metabolic pathway was investigated. BBR was demonstrated to reduce the viabilities of H22, HepG2 and Bel‑7404 cells, in a dose‑ and time‑dependent manner, and increase the number of apoptotic cells. BBR induced the translocation of apoptosis‑inducing factor between the mitochondria and the nucleus, and had no effects on the protein expression levels of caspase‑3 or ‑9. In addition, BBR significantly suppressed the protein expression levels of cytosolic phospholipase A2 (cPLA2) and cyclooxygenase (COX)‑2 and elevated the content ratio of AA to prostaglandin E2 (PGE2). Furthermore, BBR reduced the volume and weight of tumors in a H22 transplanted tumor model in mice. The results of the present study demonstrated that elevation in the ratio of AA to PGE2 via suppression of the protein expression of cPLA2 and COX‑2 in the AA metabolic pathway is involved in the inhibitory effect of BBR in HCC.

Indoline ureas as potential anti-hepatocellular carcinoma agents targeting VEGFR-2: Synthesis, in vitro biological evaluation and molecular docking

In our effort to develop potent and effective agents with anti-proliferative activity towards HepG2 hepatocellular carcinoma cells with potential inhibitory activity against VEGFR-2, a novel series of 1-(4-((2-oxoindolin-3-ylidene)amino)phenyl)-3-arylureas was designed and synthesized. All the newly prepared ureas 9a-x were evaluated in vitro for their anti-proliferative activity against HepG2 hepatocellular carcinoma cell line. Compounds 9a-c, 9e, 9f, 9j, 9m-o, 9t-v and 9x exhibited good activity against HepG2 cancer cells (IC50 = 1.22 ± 0.11-8.37 ± 0.85 μM) comparable to that of doxorubicin and sorafinib (IC50 = 2.90 ± 0.36 and 3.40 ± 0.25 μM, respectively). These thirteen compounds were further evaluated for their inhibitory activity against VEGFR-2. Compound 9x emerged as the most active counterpart against VEGFR-2 with IC50 value of 0.31 ± 0.04 μM. Furthermore, a molecular docking of the tested compounds was carried out in order to investigate their binding pattern with the prospective target, VEGFR-2 (PDB-code: 4ASD).

Evaluation of 11C-acetate and 18F-FDG PET/CT in mouse multidrug resistance gene-2 deficient mouse model of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) remains a global health problem with unique diagnostic and therapeutic challenges, including difficulties in identifying the highest risk patients. Previous work from our lab has established the murine multidrug resistance-2 mouse (MDR2) model of HCC as a reasonable preclinical model that parallels the changes seen in human inflammatory associated HCC. The purpose of this study is to evaluate modalities of PET/CT in MDR2(-/-) mice in order to facilitate therapeutic translational studies from bench to bedside.

METHODS

18F-FDG and 11C-acetate PET/CT was performed on 12 m MDR2(-/-) mice (n = 3/tracer) with HCC and 12 m MDR2(-/+) control mice (n = 3/tracer) without HCC. To compare PET/CT to biological markers of HCC and cellular function, serum alpha-fetoprotein (AFP), lysophosphatidic acid (LPA), cAMP and hepatic tumor necrosis factor α (TNFα) were quantified in 3-12 m MDR2(-/-) (n = 10) mice using commercially available ELISA analysis. To translate results in mice to patients 11C-acetate PET/CT was also performed in 8 patents suspected of HCC recurrence following treatment and currently on the liver transplant wait list.

RESULTS

Hepatic18F-FDG metabolism was not significantly increased in MDR2(-/-) mice. In contrast, hepatic 11C-acetate metabolism was significantly elevated in MDR2(-/-) mice when compared to MDR2(-/+) controls. Serum AFP and LPA levels increased in MDR2(-/-) mice contemporaneous with the emergence of HCC. This was accompanied by a significant decrease in serum cAMP levels and an increase in hepatic TNFα. In patients suspected of HCC recurrence there were 5 true positives, 2 true negatives and 1 suspected false 11C-acetate negative.

CONCLUSIONS

Hepatic 11C-acetate PET/CT tracks well with HCC in MDR2(-/-) mice and patients with underlying liver disease. Consequently 11C-acetate PET/CT is well suited to study (1) HCC emergence/progression in patients and (2) reduce animal numbers required to study new chemotherapeutics in murine models of HCC.

Vascular endothelial growth factor accelerates establishment of a model of hepatic metastasis in Walker-256 tumor-bearing rats

BACKGROUND

Animal models of secondary liver cancer are limited by the time required for the development of hepatic metastases. The authors administered vascular endothelial growth factor (VEGF) to stimulate tumor growth in a model of hepatic metastasis.

METHODS

A 0.5 to 1.0 mm³ Walker-256 carcinosarcoma tumor tissue was implanted into the livers of 45 Sprague-Dawley rats, randomly assigned to 3 equal groups to receive daily injections (0.1 mL), for 1 week, of either normal saline (control group), 20 mg/L VEGF (VEGF-20 group) or 40 mg/L VEGF (VEGF-40 group). Tumor growth was assessed by magnetic resonance imaging after 3, 7 and 14 days, and overall survival was recorded.

RESULTS

Three days after implantation, no tumors were detected by magnetic resonance imaging in the control group. In contrast, tumors were observed in 50% of rats in the VEGF-20 group and 66.7% of rats in the VEGF-40 group (P < 0.05). By day 7, tumors were detected in 92.8% of rats in the VEGF-20 group, 86.7% of rats in the VEGF-40 group, but only 21.4% of rats in the control group (P < 0.05). Tumor size increased progressively, reaching 1.81 ± 0.08, 2.51 ± 0.12 and 2.67 ± 0.10 cm³ in the control, VEGF-20 and VEGF-40 groups, respectively, 14 days after implantation of tumor tissue. Median survival times were significantly shorter in the VEGF-40 group (15 days) than in the control and VEGF-20 groups (27 and 25, respectively) (both P < 0.05).

CONCLUSIONS

Daily VEGF injection (20 mg/L, 1 week) accelerates tumorigenesis without compromising survival, potentially extending the period in which experiments can be conducted in this model.

Adjuvant chemotherapy for patients with primary hepatocellular carcinoma: a meta-analysis

Numerous studies have investigated the effects of adjuvant chemotherapy for primary hepatocellular carcinoma (HCC) patients. We conducted this analysis to evaluate the efficacy of adjuvant chemotherapy in HCC patients after hepatectomy. PubMed/MEDLINE, EMBASE, Cochrane, and other databases were searched for eligible studies. The major endpoints were overall survival (OS) and disease-free survival (DFS). The pooled odds ratio (OR) was calculated using a random-effects model to summarize the results. In the meta-analysis of 13 randomized control trials (RCTs) and 35 observational studies with 4747 patients, hepatectomy plus adjuvant chemotherapy showed superiority over hepatectomy alone in 1-year DFS (OR = 1.86, 1.38-2.51, p < 0.001), 3-year DFS (OR = 2.37, 1.73-3.24, p < 0.001) and 5-year DFS (OR = 1.99, 1.55-2.55, p < 0.001), as well as 1-year OS (OR = 2.16, 95% confidence interval 1.75-2.68, p < 0.001), 3-year OS (OR = 1.77, 1.48-2.13, p < 0.001) and 5-year OS (OR = 1.92, 1.44-2.56, p < 0.001). Subgroup and sensitivity analysis revealed that only adjuvant TACE had significant survival benefits. The meta-analysis of studies involving patients with portal vein tumor thrombus (PVTT), but not other factors related to recurrence risk, revealed favorable outcomes of the Treatment arm over the Control arm. The present study shows that adjuvant chemotherapy can improve outcomes for HCC patients. The benefits of adjuvant TACE have been confirmed whereas the effects of other adjuvant chemotherapy modalities remain uncertain. Adjuvant chemotherapy is likely to be more applicable to certain patient populations for instance those with PVTT, but further research in identifying these patient factors is of importance for tailoring adjuvant therapies to individual patients in the future.

Liver transplantation for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary tumor of the liver and is considered an aggressive tumor with mean survival estimated between 6 and 20 months. Hepatitis B and C are the most common etiologies. Pathological, laboratory and radiologic imaging all aid in diagnosis but much controversy exists in the utilization of any given modality. Many treatment options exist for management of HCC, each has its own limitation. Liver transplantation offers the most reasonable expectation for curative treatment while simultaneously removing the burden of the diseased liver. Still, advancements in the field have thus far not yet matched its potential, although new immunosuppressive and chemotherapy regimen may allow transplantation to push the envelope once again.

Synthesis and characterization of a new class of anti-angiogenic agents based on ruthenium clusters

New triruthenium-carbonyl clusters derivatized with glucose-modified bicyclophosphite ligands have been synthesized. These compounds were found to have cytostatic and cytotoxic activity and depending on the number of bicyclophosphite ligands, and could be tuned for either anti-cancer or specific anti-angiogenic activity. While some compounds had a broad cellular toxicity profile in several cell types others showed endothelial cell specific dose-dependent anti-proliferative and anti-migratory efficacy. A profound inhibition of angiogenesis was also observed in the in vivo chicken chorioallantoic membrane (CAM) model, and consequently, these new compounds have considerable potential in drug design, e.g. for the treatment of cancer.

Metformin inhibits proliferation and enhances chemosensitivity of intrahepatic cholangiocarcinoma cell lines

Metformin is an oral anti-hyperglycemic agent of the biguanide family, which is used first-line for type II diabetes with few side-effects. A recent epidemiological study that included 1,828 potential intrahepatic cholangiocarcinoma (ICC) patients showed that metformin use was significantly associated with a 60% reduction in ICC risk in diabetic patients, demonstrating the potential value of metformin in ICC management. In the present study, we firstly showed that metformin exhibited a dose- and time-dependent anti-proliferation effect on ICC cell lines, by mechanisms including apoptosis induction and cell cycle arrest. Metformin targeted the AMPK/mTORC1 pathway in ICC cells. Furthermore, metformin sensitized ICC cells to certain chemotherapeutic agents, such as sorafenib, 5-fluorouracil and As2O3 by targeting the AMPK/mTOR/HIF-1α/MRP1 pathway and ERK. As it is an inexpensive and widely used antidiabetic drug without severe adverse effects, metformin may be a prospective chemotherapeutic agent or a chemosensitizer in future ICC treatment.

Systemic cytotoxic chemotherapy of patients with advanced hepatocellular carcinoma in the era of sorafenib nonavailability

GOALS

The goal of the study was to compare the efficacy and safety of sorafenib with those of systemic cytotoxic chemotherapy.

BACKGROUND

Sorafenib treatment has shown to improve the survival in patients with advanced hepatocellular carcinoma (HCC) when compared with placebo. However, whether sorafenib controls advanced-stage HCC better than systemic cytotoxic chemotherapy has not been elucidated.

STUDY

We retrospectively reviewed the medical records of 220 patients with measurable advanced HCC who had not received systemic treatment previously between January 2007 and April 2012. Among these patients, 78 had been treated with sorafenib. Another 14 patients who were treated with a 4-weekly regimen of adriamycin, cisplatin, and capecitabine were included as the historical control group for comparison. The median overall survival, the progression-free survival, response rates, and safety profiles were evaluated.

RESULTS

Baseline characteristics were similar between the treatment groups. The median overall survival was 7.2 months [95% confidence interval (CI), 5.6-8.8] in the sorafenib group and 11.2 months (95% CI, 8.1-14.2) in the cytotoxic chemotherapy group (P=0.10). The median progression-free survival was 3.2 months (95% CI, 2.2-4.3) in the sorafenib group and 5.9 months (95% CI, 3.6-8.2) in the cytotoxic chemotherapy group (P=0.07). The deterioration of liver function and neutropenia were the most frequent serious adverse events in the sorafenib and the systemic chemotherapy group.

CONCLUSIONS

Although a direct head-to-head comparison could not be done, there were some patients who showed a good response to systemic cytotoxic chemotherapy. Further assessment is necessary to study the role of chemotherapy in patients who are intolerant or intractable to sorafenib.

[Current status of molecular targeted therapies in hepatocellular carcinoma]

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death in Korea. Curative treatment is only possible when the disease is diagnosed at the early stage. The prognosis of patients with HCC is even dismal in advanced stages. No systemic cytotoxic chemotherapy has proven to be beneficial in overall survival. Recently, the understanding of the molecular pathogenesis led to the development of new therapies. With the evidence of dysregulation of critical genes associated with cellular proliferation, growth factor signaling, cell cycling, apoptosis, and angiogenesis in HCC, a number of molecular target agents are under clinical trials. Sorafenib is the first systemic anticancer drug which has proven to gain survival benefit in the global as well as Asia-Pacific trials. However, the survival gain is still modest, and further efforts to improve outcomes in patients with HCC are necessary by developing novel drugs or combining other forms of therapies. This article will review signaling pathways in HCC and introduce molecular target agents under investigation currently.

Establishment of stable reporter expression for in vivo imaging of nuclear factor-κB activation in mouse liver

The nuclear factor-κB (NF-κB) signaling pathway plays a critical role in a multitude of cellular processes. Activation of the NF-κB transcription factor family is essential for the initiation of inflammation, immunity, cell proliferation and apoptosis through a list of responsive genes. In hepatic tissue, activation of the NF-κB pathway has been implicated in a number of pathological conditions. Here we described a mouse model for noninvasive quantification of NF-κB activation in the hepatic tissues. Mice were subjected to hydrodynamic delivery with a mixture of pattB-NF-κB-Fluc reporter and φC31o integrase vector. Hepatic expression of φC31o integrase mediated chromosomal integration of the pattB-NF-κB-Fluc reporter, resulting in stable luciferase expression at 300 days post transfection. We applied noninvasive imaging and were able to detect NF-κB activation under acute liver injury and hepatitis conditions. During hepatectomy-induced liver regeneration, NF-κB activation was detected locally in the tissues at the surgery site. Treatment with Sorafenib suppressed NF-κB activation, accompanied with perturbation of liver regeneration. In conclusion, we established a method for stable transfection of the hepatic tissues and applied the transfected mice to longitudinal monitoring of NF-κB activity under pathological conditions. Further exploration of this methodology for establishment of other disease models and for evaluation of novel pharmaceuticals is likely to be fruitful.

Systemic therapy for hepatocellular carcinoma (HCC): from bench to bedside

Primary liver cancer is the fifth most common cancer worldwide and the third most common cause of cancer mortality. For patients with early resectable disease, surgical resection or transplantation is considered a potentially curative modality for hepatocellular carcinoma (HCC); on the other hand, for patients with unresectable or metastatic disease, treatment is essentially palliative and prior to the approval of sorafenib, there was no globally approved systemic treatment for patients presenting with unresectable or metastatic HCC. Sorafenib is the only systemic treatment to demonstrate a statistically significant but modest overall survival benefit in a large phase III trial. Thus, novel systemic approaches represent a high unmet medical need in advanced HCC. In this review article, we will try to take a journey through the history of systemic therapeutic options for HCC passing through the current standard options and exploring the potential new systemic options for this disease.

Low glucose promotes CD133mAb-elicited cell death via inhibition of autophagy in hepatocarcinoma cells

CD133 on cancer stem cells is a potential therapeutic target. In this study, CD133 antibody (CD133mAb) treatment resulted in cell death in hepatoma LM3, HepG2, Hep3B and Huh-7 cells, especially under low glucose condition. The treatment also inhibited formation of spheroids, colonies, and xenograft tumors. Ectopic CD133 enabled hepatocyte L02 to be suppressed by CD133mAb and increased spheroid formation. CD133mAb caused cell death in primary HCC cells and sensitized them to Doxorubicin and Cisplatin. The antibody effect was attributed to suppressing autophagy and promoting necrotic cell death. Therefore, targeting CD133 under low glucose condition is a potential therapeutic approach for hepatocarcinomas.

Discovery of hybrid dual N-acylhydrazone and diaryl urea derivatives as potent antitumor agents: design, synthesis and cytotoxicity evaluation

Based on the hybrid pharmacophore design concept, a novel series of dual diaryl urea and N-acylhydrazone derivatives were synthesized and evaluated for their in vitro cytotoxicity by the standard MTT assay. The pharmacological results indicated that most compounds exhibited moderate to excellent activity. Moreover, compound 2g showed the most potent cytotoxicity against HL-60, A549 and MDA-MB-231 cell lines, with IC₅₀ values of 0.22, 0.34 and 0.41 μM, respectively, which was 3.8 to 22.5 times more active than the reference compounds sorafenib and PAC-1. The promising compound 2g thus emerges as a lead for further structural modifications.

Hepatitis C virus-related hepatocellular carcinoma: An insight into molecular mechanisms and therapeutic strategies

Hepatitis C virus (HCV) infects more than 170 million people worldwide, and thereby becomes a series global health challenge. Chronic infection with HCV is considered one of the major causes of end-stage liver disease including cirrhosis and hepatocellular carcinoma. Although the multiple functions of the HCV proteins and their impacts on the modulation of the intracellular signaling transduction processes, the drive of carcinogenesis during the infection with HCV, is thought to result from the interactions of viral proteins with host cell proteins. Thus, the induction of mutator phenotype, in liver, by the expression of HCV proteins provides a key mechanism for the development of HCV-associated hepatocellular carcinoma (HCC). HCC is considered one of the most common malignancies worldwide with increasing incidence during the past decades. In many countries, the trend of HCC is attributed to several liver diseases including HCV infection. However, the development of HCC is very complicated and results mainly from the imbalance between tumor suppressor genes and oncogenes, as well as from the alteration of cellular factors leading to a genomic instability. Besides the poor prognosis of HCC patients, this type of tumor is quite resistance to the available therapies. Thus, understanding the molecular mechanisms, which are implicated in the development of HCC during the course of HCV infection, may help to design a general therapeutic protocol for the treatment and/or the prevention of this malignancy. This review summarizes the current knowledge of the molecular mechanisms, which are involved in the development of HCV-associated HCC and the possible therapeutic strategies.

Vascular endothelial growth factor (VEGF) receptors: drugs and new inhibitors

The recent launch onto the market of five VEGFR inhibitors indicates the therapeutic value of these agents and the importance of the research in the field of angiogenesis inhibitors for future oncologic therapy. In this Perspective we briefly report the inhibitors that are in clinical use, while we dedicate two wider sections to the compounds that are in clinical trials and to the new derivatives appearing in the literature. We especially consider the medicinal chemistry aspect of the topic and report the structure-activity relationship studies and the binding mode of some inhibitors as well as the biological data of the compounds discovered in the past 5 years.