Activation of phosphatidylinositol 3-kinase/Akt signaling pathway mediates acquired resistance to sorafenib in hepatocellular carcinoma cells

cGAS suppresses hepatocellular carcinoma independent of its cGAMP synthase activity

Cyclic GMP-AMP synthase (cGAS) is a key innate immune sensor that recognizes cytosolic DNA to induce immune responses against invading pathogens. The role of cGAS is conventionally recognized as a nucleotidyltransferase to catalyze the synthesis of cGAMP upon recognition of cytosolic DNA, which leads to the activation of STING and production of type I/III interferon to fight against the pathogen. However, given that hepatocytes are lack of functional STING expression, it is intriguing to define the role of cGAS in hepatocellular carcinoma (HCC), the liver parenchymal cells derived malignancy. In this study, we revealed that cGAS was significantly downregulated in clinical HCC tissues, and its dysregulation contributed to the progression of HCC. We further identified cGAS as an immune tyrosine inhibitory motif (ITIM) containing protein, and demonstrated that cGAS inhibited the progression of HCC and increased the response of HCC to sorafenib treatment by suppressing PI3K/AKT/mTORC1 pathway in cellular and animal models. Mechanistically, cGAS recruits SH2-containing tyrosine phosphatase 1 (SHP1) via ITIM, and dephosphorylates p85 in phosphatidylinositol 3-kinase (PI3K), which leads to the suppression of AKT-mTORC1 pathway. Thus, cGAS is identified as a novel tumor suppressor in HCC via its function independent of its conventional role as cGAMP synthase, which indicates a novel therapeutic strategy for advanced HCC by modulating cGAS signaling.

Mechanisms of Sorafenib Resistance in HCC Culture Relate to the Impaired Membrane Expression of Organic Cation Transporter 1 (OCT1)

Introduction

Sorafenib, an FDA-approved drug for advanced hepatocellular carcinoma (HCC) treatment, encounters resistance in many patients. Deciphering the mechanisms underlying sorafenib resistance is crucial for devising alternative strategies to overcome it.

Aim

This study aimed to investigate sorafenib resistance mechanisms using a diverse panel of HCC cell lines.

Methods

HCC cell lines were subjected to continuous sorafenib treatment, and stable cell lines (Huh 7.5 and Huh 7PX) exhibiting sustained growth in its presence were isolated. The investigation of drug resistance mechanisms involved a comparative analysis of drug-targeted signal transduction pathways (EGFR/RAF/MEK/ERK/Cyclin D), sorafenib uptake, and membrane expression of the drug uptake transporter.

Results

HCC cell lines (Huh 7.5 and Huh 7PX) with a higher IC50 (10μM) displayed a more frequent development of sorafenib resistance compared to those with a lower IC50 (2-4.8μM), indicating a potential impact of IC50 variation on initial treatment response. Our findings reveal that activated overexpression of Raf1 kinases and impaired sorafenib uptake, mediated by reduced membrane expression of organic cation transporter-1 (OCT1), contribute to sorafenib resistance in HCC cultures. Stable expression of the drug transporter OCT1 through cDNA transfection or adenoviral delivery of OCT1 mRNA increased sorafenib uptake and successfully overcame sorafenib resistance. Additionally, consistent with sorafenib resistance in HCC cultures, cirrhotic liver-associated human HCC tumors often exhibited impaired membrane expression of OCT1 and OCT3.

Conclusion

Intrinsic differences among HCC cell clones, affecting sorafenib sensitivity at the expression level of Raf kinases, drug uptake, and OCT1 transporters, were identified. This study underscores the potential of HCC tumor targeted OCT1 expression to enhance sorafenib treatment response.

Global research status and frontiers on autophagy in hepatocellular carcinoma: a comprehensive bibliometric and visualized analysis

BACKGROUND

An extensive body of research has explored the role of autophagy in hepatocellular carcinoma (HCC), revealing its critical involvement in the disease's pathogenesis, progression, and therapeutic targeting. However, there is a discernible deficit in quantitative, analytical studies concerning autophagy in the context of HCC. Accordingly, this investigation endeavored to meticulously assess the evolution of autophagy research, employing bibliometric citation analysis to offer a comprehensive evaluation of the findings in this field.

METHODS

The authors conducted a literature search on 2 August 2023, to extract relevant publications spanning from 2013 to 2022, indexed in the Science Citation Index-Expanded (SCIE) of the Web of Science Core Collection (WOSCC). Subsequently, the authors performed a bibliometric assessment of the compiled documents using visualization tools such as CiteSpace and VOSviewer.

RESULTS

The search yielded 734 publications penned by 4699 authors, encompassing contributions from 41 countries and 909 institutions, disseminated across 272 journals, and comprising 26 295 co-cited references from 2667 journals. Notably, China led in publication volume with 264 articles (amounting to 35.9%) and exhibited the most robust collaboration with the United States. The mechanisms underlying autophagy's influence on the emergence and advancement of HCC, as well as the implicated proteins and genes, have garnered significant attention. In recent years, investigations of targeting autophagy and the resistance to sorafenib have surfaced as pivotal themes and emerging frontiers in this domain.

CONCLUSIONS

This study rigorously collated and distilled the prevailing research narratives and novel insights on autophagy in HCC. The resultant synthesis provides a substantive foundation for medical professionals and researchers, as well as pivotal implications for future investigative endeavors in this arena.

Comprehensive analysis of m6A modification in immune infiltration, metabolism and drug resistance in hepatocellular carcinoma

N6-methyladenosine (m6A) is important in regulating mRNA stability, splicing, and translation, and it also contributes to tumor development. However, there is still limited understanding of the comprehensive effects of m6A modification patterns on the tumor immune microenvironment, metabolism, and drug resistance in hepatocellular carcinoma (HCC). In this study, we utilized unsupervised clustering based on the expression of 23 m6A regulators to identify m6A clusters. We identified differential m6A modification patterns and characterized m6A-gene-cluster A, which exhibited poorer survival rates, a higher abundance of Treg cells, and increased expression of TGFβ in the tumor microenvironment (TME). Additionally, m6A-gene-cluster A demonstrated higher levels of glycolysis activity, cholesterol metabolism, and fatty acid biosynthesis. We also found that the m6A score was associated with prognosis and drug resistance. Patients with a low m6A score experienced worse prognoses, which were linked to an abundance of Treg cells, upregulation of TGFβ, and increased metabolic activity. HCC patients with a higher m6A score showed improved prognosis following sorafenib treatment and immunotherapy. In conclusion, we reveals the association between m6A modification patterns and the tumor immune microenvironment, metabolism, and drug resistance in HCC. Furthermore, the m6A score holds potential as a predictive factor for the efficacy of targeted therapy and immunotherapy in HCC.

Mechanisms of drug resistance in HCC

HCC comprises ∼80% of primary liver cancer. HCC is the only major cancer for which death rates have not improved over the last 10 years. Most patients are diagnosed with advanced disease when surgical and locoregional treatments are not feasible or effective. Sorafenib, a multikinase inhibitor targeting cell growth and angiogenesis, was approved for advanced unresectable HCC in 2007. Since then, other multikinase inhibitors have been approved. Lenvatinib was found to be noninferior to sorafenib as a first-line agent. Regorafenib, cabozantinib, and ramucirumab were shown to prolong survival as second-line agents. Advances in immunotherapy for HCC have also added hope for patients, but their efficacy remains limited. A large proportion of patients with advanced HCC gain no long-term benefit from systemic therapy due to primary and acquired drug resistance, which, combined with its rising incidence, keeps HCC a highly fatal disease. This review summarizes mechanisms of primary and acquired resistance to therapy and includes methods for bypassing resistance. It addresses recent advancements in immunotherapy, provides new perspectives on the linkage between drug resistance and molecular etiology of HCC, and evaluates the role of the microbiome in drug resistance. It also discusses alterations in signaling pathways, dysregulation of apoptosis, modulations in the tumor microenvironment, involvement of cancer stem cells, changes in drug metabolism/transport, tumor hypoxia, DNA repair, and the role of microRNAs in drug resistance. Understanding the interplay among these factors will provide guidance on the development of new therapeutic strategies capable of improving patient outcomes.

LINC00540 promotes sorafenib resistance and functions as a ceRNA for miR-4677-3p to regulate AKR1C2 in hepatocellular carcinoma

Sorafenib resistance is one of the main causes of poor prognosis in patients with advanced hepatocellular carcinoma (HCC). Long noncoding RNAs (lncRNAs) function as suppressors or oncogenic factors during tumor progression and drug resistance. Here, to identify therapeutic targets for HCC, the biological mechanisms of abnormally expressed lncRNAs were examined in sorafenib-resistant HCC cells. Specifically, we established sorafenib-resistant HCC cell lines (Huh7-S and SMMC7721-S), which displayed an epithelial-mesenchymal transition (EMT) phenotype. Transcriptome sequencing (RNA-Seq) was performed to established differential lncRNA expression profiles for sorafenib-resistant cells. Through this analysis, we identified LINC00540 as significantly up-regulated in sorafenib-resistant cells and a candidate lncRNA for further mechanistic investigation. Functionally, LINC00540 knockdown promoted sorafenib sensitivity and suppressed migration, invasion, EMT and the activation of PI3K/AKT signaling pathway in sorafenib-resistant HCC cells, whereas overexpression of LINC00540 resulted in the opposite effects in parental cells. LINC00540 functions as a competing endogenous RNA (ceRNA) by competitively binding to miR-4677-3p , thereby promoting AKR1C2 expression. This is the first study that demonstrates a role for LINC00540 in enhancing sorafenib resistance, migration and invasion of HCC cells through the LINC00540/miR-4677-3p/AKR1C2 axis, suggesting that LINC00540 may represent a potential therapeutic target and prognosis biomarker for HCC.

Exosomal miR-93 derived from hepatocellular carcinoma cell promotes the sorafenib resistance of hepatocellular carcinoma through PTEN/PI3K/Akt pathway

Exosomal microRNAs (miRNAs) derived from cancer cell is an important regulatory molecule that mediates the formation of tumor drug resistance, but function and mechanisms of exosomal miRNA in sorafenib resistance of hepatocellular carcinoma (HCC) have not been studied. We detected the level and prognosis of miR-93 in HCC by using TCGA HCC database. For confirming the extracted exosome, transmission electron microscopy was used. Cy3-labeled miR-93 and quantitative reverse transcription-polymerase chain reaction were used to prove that exosomal miR-93 derived from HCC cell can be transferred to sensitive HCC cells. CCK8, EdU, and flow cytometer assay were used to confirm the function of exosomal miR-93 in sorafenib resistance of HCC. Bioinformatics software and luciferase reporter assay was used to confirm the direct targeting relationship between PTEN and miR-93. Western blot was used to validate downstream pathways. We found that miR-93 is overexpressed and a prognostic risk factor for the HCC patients. miR-93 was overexpressed in sorafenib resistant HCC cells compared with sensitive cells, and miR-93 contributed to sorafenib resistance of HCC cells through targeting PTEN. miR-93 was enriched in exosomes that secreted from sorafenib resistant cells, and these exosomal miR-93 promote the spread of sorafenib resistant through targeting PTEN to reactivate PI3K/AKT pathway. Therefore, miR-93 can act as a potential therapeutic target for advanced patients with acquired sorafenib resistance.

The pharmacological role of Ginsenoside Rg3 in liver diseases: A review on molecular mechanisms

Liver diseases are a significant global health burden and are among the most common diseases. Ginssennoside Rg3 (Rg3), which is one of the most abundant ginsenosides, has been found to have significant preventive and therapeutic effects against various types of diseases with minimal side effects. Numerous studies have demonstrated the significant preventive and therapeutic effects of Rg3 on various liver diseases such as viral hepatitis, acute liver injury, nonalcoholic liver diseases (NAFLD), liver fibrosis and hepatocellular carcinoma (HCC). The underlying molecular mechanism behind these effects is attributed to apoptosis, autophagy, antioxidant, anti-inflammatory activities, and the regulation of multiple signaling pathways. This review provides a comprehensive description of the potential molecular mechanisms of Rg3 in the development of liver diseases. The article focuses on the regulation of apoptosis, oxidative stress, autophagy, inflammation, and other related factors. Additionally, the review discusses combination therapy and liver targeting strategy, which can accelerate the translation of Rg3 from bench to bedside. Overall, this article serves as a valuable reference for researchers and clinicians alike.

The anti-hepatocellular carcinoma effect of Aidi injection was related to the synergistic action of cantharidin, formononetin, and isofraxidin through BIRC5, FEN1, and EGFR

ETHNOPHARMACOLOGICAL RELEVANCE

Aidi injection (ADI) is a popular anti-tumor Chinese patent medicine, widely used in clinics for the treatment of hepatocellular carcinoma (HCC) with remarkable therapeutic effects through multiple targets and pathways. However, the scientific evidence of the synergistic role of the complex chemical component system and the potential mechanism for treating diseases are ignored and remain to be elucidated.

AIM OF THE STUDY

This study aimed to elucidate and verify the cooperative association between the potential active ingredient of ADI, which is of significance to enlarge our understanding of its anti-HCC molecular mechanisms.

MATERIALS AND METHODS

Firstly, the anti-HCC effect of ADI was evaluated in various HCC cells and the zebrafish xenograft model. Subsequently, a variety of bioinformatic technologies, including network pharmacology, weighted gene co-expression network analysis (WGCNA), meta-analysis of gene expression profiles, and pathway enrichment analysis were performed to construct the competitive endogenous RNA (ceRNA) network of ADI intervention in HCC and to establish the relationship between the critical targets/pathways and the key corresponding components, which were involved in ADI against HCC in a synergistic way and were validated by molecular biology experiments.

RESULTS

ADI exerted remarkable anti-HCC in vitro cells and in vivo zebrafish model, especially that the Hep 3B2.1-7 cell showed substantial sensibility to ADI. The ceRNA network revealed that the EGFR/PI3K/AKT signaling pathway was identified as the promising pathway. Furthermore, the meta-analysis also demonstrated the critical role of BIRC5 and FEN1 as key targets. Finally, the synergistic effect of ADI was revealed by discovering the inhibitory effect of cantharidin on BIRC5, formononetin on FEN1 and EGFR, as well as isofraxidin on EGFR.

CONCLUSION

Our study unveiled that the incredible protective effect of ADI on HCC resulted from the synergistic inhibition effect of cantharidin, formononetin, and isofraxidin on multiple targets/pathways, including BIRC5, FEN1, and EGFR/PI3K/AKT, respectively, providing a scientific interpretation of ADI against HCC and a typical example of pharmacodynamic evaluation of other proprietary Chinese patent medicine.

The Impact of Statins on the Survival of Patients with Advanced Hepatocellular Carcinoma Treated with Sorafenib or Lenvatinib

We aimed to evaluate the survival benefits of coadministering statins and multityrosine kinase inhibitors (TKIs) in patients with advanced hepatocellular carcinoma (HCC). Data from the Health Insurance Review and Assessment Service in Korea (2010-2020) were utilized. Statin use (≥28 cumulative defined daily doses) was analyzed, with 1534 statin users matched to 6136 non-users (1:4 ratio) using propensity scores. Primary and secondary outcomes were overall survival (OS) and progression-free survival (PFS). Statin use significantly improved OS (hazard ratio [HR] 0.77, 95% confidence interval [CI] 0.72-0.82, p < 0.001) and PFS (HR 0.78, 95% CI 0.74-0.84, p < 0.001). Continuous or post-TKI statin users had better OS, while discontinuation after TKI use led to poorer OS. Both lipophilic and hydrophilic statins improved OS and PFS, particularly with ≥730 cumulative defined daily doses. In conclusion, combining statins and TKIs in patients with advanced HCC yielded significant survival benefits, influenced by statin dosage and duration. Continuous statin administration post-TKI treatment is crucial for improving outcomes in patients with HCC.

The role of ncRNA in the co-regulation of autophagy and exosome pathways during cancer progression

Since its discovery a few decades ago, autophagy has been recognized as a crucial signaling pathway, linked to the recycling of cellular components in nutrient stress. Autophagy is a two-way sword, playing a dual role in tumorigenesis. In this catabolic process, dysfunctional organelles, biomolecules, and misfolded proteins are sequestered in the autophagosome and sent to the lysosome for degradation. Alongside, there are cellular messengers called exosomes, which are released from cells and are known to communicate and regulate metabolism in recipient cells. Multivesicular bodies (MVB) act as the intricate link between autophagy and exosome pathways. The continuous crosstalk between the two pathways is coordinated and regulated by multiple players among which ncRNA is the emerging candidates. The exosomes carry varied cargo of which non-coding RNA exerts an immediate regulatory effect on recipient cells. ncRNA is known to exhibit dual behavior in both promoting and inhibiting tumor growth. There is increasing evidence for the involvement of ncRNAs' in the regulation of different hallmarks of cancer. Different ncRNAs are involved in the co-regulation of autophagy and exosome pathways and therefore represent a superior therapeutic approach to target cancer chemoresistance. Here, we will discuss the ncRNA involved in regulating autophagy, and exosomes pathways and its relevance in cancer therapeutics.

MiR-494 induces metabolic changes through G6pc targeting and modulates sorafenib response in hepatocellular carcinoma

BACKGROUND

Metabolic reprogramming is a well-known marker of cancer, and it represents an early event during hepatocellular carcinoma (HCC) development. The recent approval of several molecular targeted agents has revolutionized the management of advanced HCC patients. Nevertheless, the lack of circulating biomarkers still affects patient stratification to tailored treatments. In this context, there is an urgent need for biomarkers to aid treatment choice and for novel and more effective therapeutic combinations to avoid the development of drug-resistant phenotypes. This study aims to prove the involvement of miR-494 in metabolic reprogramming of HCC, to identify novel miRNA-based therapeutic combinations and to evaluate miR-494 potential as a circulating biomarker.

METHODS

Bioinformatics analysis identified miR-494 metabolic targets. QPCR analysis of glucose 6-phosphatase catalytic subunit (G6pc) was performed in HCC patients and preclinical models. Functional analysis and metabolic assays assessed G6pc targeting and miR-494 involvement in metabolic changes, mitochondrial dysfunction, and ROS production in HCC cells. Live-imaging analysis evaluated the effects of miR-494/G6pc axis in cell growth of HCC cells under stressful conditions. Circulating miR-494 levels were assayed in sorafenib-treated HCC patients and DEN-HCC rats.

RESULTS

MiR-494 induced the metabolic shift of HCC cells toward a glycolytic phenotype through G6pc targeting and HIF-1A pathway activation. MiR-494/G6pc axis played an active role in metabolic plasticity of cancer cells, leading to glycogen and lipid droplets accumulation that favored cell survival under harsh environmental conditions. High miR-494 serum levels associated with sorafenib resistance in preclinical models and in a preliminary cohort of HCC patients. An enhanced anticancer effect was observed for treatment combinations between antagomiR-494 and sorafenib or 2-deoxy-glucose in HCC cells.

CONCLUSIONS

MiR-494/G6pc axis is critical for the metabolic rewiring of cancer cells and associates with poor prognosis. MiR-494 deserves attention as a candidate biomarker of likelihood of response to sorafenib to be tested in future validation studies. MiR-494 represents a promising therapeutic target for combination strategies with sorafenib or metabolic interference molecules for the treatment of HCC patients who are ineligible for immunotherapy.

Erratum: Drug resistance mechanism of kinase inhibitors in the treatment of hepatocellular carcinoma

[This corrects the article DOI: 10.3389/fphar.2023.1097277.].

FOXM1 augments sorafenib resistance and promotes progression of hepatocellular carcinoma by epigenetically activating KIF23 expression

Sorafenib has been used to enhance the survival outcome of hepatocellular carcinoma (HCC) patients. But, occurrence resistance to sorafenib subtracts from its therapeutic benefits. Herein, we identified that FOXM1 was markedly upregulated in both tumor samples and sorafenib-resistant HCC tissues. We also demonstrated that patients with decreased FOXM1 expression had longer overall survival (OS) and progression-free survival (PFS) in the cohort of sorafenib-treated patients. For HCC cells resistant to sorafenib, the IC50 value of sorafenib and the expression of FOXM1 were increased. In addition, Downregulation of FOXM1 expression alleviated the occurrence of resistance to sorafenib and reduced the proliferative potential and viability of HCC cells. Mechanically, the suppression of the FOXM1 gene resulted in the downregulation of KIF23 levels. Moreover, downregulation of FOXM1 expression reduced the levels of RNA polymerase II (RNA pol II) and histone H3 lysine 27 acetylation (H3K27ac) on the KIF23 promoter, further epigenetically silencing the production of KIF23. More intriguingly, our results similarly revealed that FDI-6, a specific inhibitor of FOXM1, suppressed the proliferation of HCC cells resistant to sorafenib, as well as upregulation of FOXM1 or KIF23 abolished this effect. In addition, we found that FDI-6 combined with sorafenib significantly improved the therapeutic effect of sorafenib. Collectively, the present results revealed that FOXM augments sorafenib resistance and enhances HCC progression by upregulating KIF23 expression via an epigenetic mechanism, and targeting FOXM1 can be an effective treatment for HCC.

Current therapeutic modalities and chemopreventive role of natural products in liver cancer: Progress and promise

Liver cancer is a severe concern for public health officials since the clinical cases are increasing each year, with an estimated 5-year survival rate of 30%–35% after diagnosis. Hepatocellular carcinoma (HCC) constitutes a significant subtype of liver cancer (approximate75%) and is considered primary liver cancer. Treatment for liver cancer mainly depends on the stage of its progression, where surgery including, hepatectomy and liver transplantation, and ablation and radiotherapy are the prime choice. For advanced liver cancer, various drugs and immunotherapy are used as first-line treatment, whereas second-line treatment includes chemotherapeutic drugs from natural and synthetic origins. Sorafenib and lenvatinib are first-line therapies, while regorafenib and ramucirumab are second-line therapy. Various metabolic and signaling pathways such as Notch, JAK/ STAT, Hippo, TGF-β, and Wnt have played a critical role during HCC progression. Dysbiosis has also been implicated in liver cancer. Drug-induced toxicity is a key obstacle in the treatment of liver cancer, necessitating the development of effective and safe medications, with natural compounds such as resveratrol, curcumin, diallyl sulfide, and others emerging as promising anticancer agents. This review highlights the current status of liver cancer research, signaling pathways, therapeutic targets, current treatment strategies and the chemopreventive role of various natural products in managing liver cancer.

SOCS2 protects against chemical-induced hepatocellular carcinoma progression by modulating inflammation and cell proliferation in the liver

Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancers worldwide, but the precise intracellular mechanisms underlying the progression of this inflammation associated cancer are not well established. SOCS2 protein plays an important role in the carcinogenesis of different tumors by regulating cytokine signalling through the JAK/STAT axis. However, its role in HCC is unclear. Here, we investigate the role of SOCS2 in HCC progression and its potential as HCC biomarker. The effects of SOCS2 in HCC progression were evaluated in an experimental model of diethylnitrosamine (DEN)-induced HCC in C57BL/6 and SOCS2 deficient mice, in cultured hepatic cells, and in liver samples from HCC patients. Mice lacking SOCS2 showed higher liver tumor burden with increased malignancy grade, inflammation, fibrosis, and proliferation than their controls. Protein and gene expression analysis reported higher pSTAT5 and pSTAT3 activation, upregulation of different proteins involved in survival and proliferation, and increased levels of proinflammatory and pro-tumoral mediators in the absence of SOCS2. Clinically relevant, downregulated expression of SOCS2 was found in neoplasia from HCC patients compared to healthy liver tissue, correlating with the malignancy grade. In summary, our data show that lack of SOCS2 increases susceptibility to chemical-induced HCC and suggest the tumor suppressor role of this protein by regulating the oncogenic and inflammatory responses mediated by STAT5 and STAT3 in the liver. Hence, SOCS2 emerges as an attractive target molecule and potential biomarker to deepen in the study of HCC treatment.

Drug resistance mechanism of kinase inhibitors in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer, and it usually occurs following chronic liver disease. Although some progress has been made in the treatment of HCC, the prognosis of patients with advanced HCC is not optimistic, mainly because of the inevitable development of drug resistance. Therefore, multi-target kinase inhibitors for the treatment of HCC, such as sorafenib, lenvatinib, cabozantinib, and regorafenib, produce small clinical benefits for patients with HCC. It is necessary to study the mechanism of kinase inhibitor resistance and explore possible solutions to overcome this resistance to improve clinical benefits. In this study, we reviewed the mechanisms of resistance to multi-target kinase inhibitors in HCC and discussed strategies that can be used to improve treatment outcomes.

HMGCS2 Mediation of Ketone Levels Affects Sorafenib Treatment Efficacy in Liver Cancer Cells

Primary liver cancer is the fifth leading death of cancers in men, and hepatocellular carcinoma (HCC) accounts for approximately 90% of all primary liver cancer cases. Sorafenib is a first-line drug for advanced-stage HCC patients. Sorafenib is a multi-target kinase inhibitor that blocks tumor cell proliferation and angiogenesis. Despite sorafenib treatment extending survival, some patients experience side effects, and sorafenib resistance does occur. 3-Hydroxymethyl glutaryl-CoA synthase 2 (HMGCS2) is the rate-limiting enzyme for ketogenesis, which synthesizes the ketone bodies, β-hydroxybutyrate (β-HB) and acetoacetate (AcAc). β-HB is the most abundant ketone body which is present in a 4:1 ratio compared to AcAc. Recently, ketone body treatment was found to have therapeutic effects against many cancers by causing metabolic alternations and cancer cell apoptosis. Our previous publication showed that HMGCS2 downregulation-mediated ketone body reduction promoted HCC clinicopathological progression through regulating c-Myc/cyclin D1 and caspase-dependent signaling. However, whether HMGCS2-regulated ketone body production alters the sensitivity of human HCC to sorafenib treatment remains unclear. In this study, we showed that HMGCS2 downregulation enhanced the proliferative ability and attenuated the cytotoxic effects of sorafenib by activating expressions of phosphorylated (p)-extracellular signal-regulated kinase (ERK), p-P38, and p-AKT. In contrast, HMGCS2 overexpression decreased cell proliferation and enhanced the cytotoxic effects of sorafenib in HCC cells by inhibiting ERK activation. Furthermore, we showed that knockdown HMGCS2 exhibited the potential migratory ability, as well as decreasing zonula occludens protein (ZO)-1 and increasing c-Myc expression in both sorafenib-treated Huh7 and HepG2 cells. Although HMGCS2 overexpression did not alter the migratory effect, expressions of ZO-1, c-Myc, and N-cadherin decreased in sorafenib-treated HMGCS2-overexpressing HCC cells. Finally, we investigated whether ketone treatment influences sorafenib sensitivity. We showed that β-HB pretreatment decreased cell proliferation and enhanced antiproliferative effect of sorafenib in both Huh7 and HepG2 cells. In conclusion, this study defined the impacts of HMGCS2 expression and ketone body treatment on influencing the sorafenib sensitivity of liver cancer cells.

Targeted Therapies for Hepatocellular Carcinoma Treatment: A New Era Ahead-A Systematic Review

Hepatocellular carcinoma (HCC) remains one of the most common malignancies and the third cause of cancer-related death worldwide, with surgery being the best prognostic tool. Among the well-known causative factors of HCC are chronic liver virus infections, chronic virus hepatitis B (HBV) and chronic hepatitis virus C (HCV), aflatoxins, tobacco consumption, and non-alcoholic liver disease (NAFLD). There is a need for the development of efficient molecular markers and alternative therapeutic targets of great significance. In this review, we describe the general characteristics of HCC and present a variety of targeted therapies that resulted in progress in HCC therapy.

Small Molecule Inhibitors for Hepatocellular Carcinoma: Advances and Challenges

According to data provided by World Health Organization, hepatocellular carcinoma (HCC) is the sixth most common cause of deaths due to cancer worldwide. Tremendous progress has been achieved over the last 10 years developing novel agents for HCC treatment, including small-molecule kinase inhibitors. Several small molecule inhibitors currently form the core of HCC treatment due to their versatility since they would be more easily absorbed and have higher oral bioavailability, thus easier to formulate and administer to patients. In addition, they can be altered structurally to have greater volumes of distribution, allowing them to block extravascular molecular targets and to accumulate in a high concentration in the tumor microenvironment. Moreover, they can be designed to have shortened half-lives to control for immune-related adverse events. Most importantly, they would spare patients, healthcare institutions, and society as a whole from the burden of high drug costs. The present review provides an overview of the pharmaceutical compounds that are licensed for HCC treatment and other emerging compounds that are still investigated in preclinical and clinical trials. These molecules are targeting different molecular targets and pathways that are proven to be involved in the pathogenesis of the disease.

Fucoidan inhibits EGFR redistribution and potentiates sorafenib to overcome sorafenib-resistant hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. Although sorafenib is a standard first-line molecule-targeted drug against advanced HCC, the drug resistance development and adverse side effects usually limit its efficacy. This study investigated the effect of fucoidan on the sorafenib sensitivity of sorafenib-resistant human HCC cell line HepG2-SR established by long-time exposure of HepG2 to sorafenib. We demonstrated fucoidan combined with sorafenib synergistically promoted apoptosis and cell cycle arrest whereas inhibited cell migration in HepG2-SR cells. This combination treatment effectively suppressed the cellular epithelial growth factor receptor (EGFR) nuclear distribution and downstream gene transcription. Interestingly, fucoidan bound the cell surface EGFR, dampening EGFR translocation to lipid raft and further nuclear distribution, restoring the sorafenib sensitivity in HepG2-SR cells. Blocking fucoidan-EGFR interaction using EGFR antibody restrained the enhanced anti-tumor effects upon the combined administration. Besides, EGFR knockdown abolished the combination treatment-improved anti-tumor efficacy. This combination also suppressed in vivo xenograft tumor growth in nude mice. Our present study uncovered that fucoidan overcame sorafenib resistance in HCC via its interaction with cell membrane EGFR and further suppression of EGFR redistribution and downstream signaling in sorafenib-resistant cells. Overall, current results suggest that simultaneous treatment of fucoidan and sorafenib might serve as a potential therapeutic strategy against sorafenib-resistant HCC.

Sorafenib combined with STAT3 knockdown triggers ER stress-induced HCC apoptosis and cGAS-STING-mediated anti-tumor immunity

Sorafenib is the first-line treatment for advanced hepatocellular carcinoma (HCC). However, it is difficult to alleviate this disease process using single-agent chemotherapy. Using combination therapies for advanced HCC has become a major trend. Given that STAT3 overexpression is involved in chemotherapy resistance and the immune escape of HCC cells, it has become a potential therapeutic target for HCC in recent years. GEO database analysis showed that STAT3 levels in tumor tissues from non-responders were significantly higher than those in responders to sorafenib. Our studies demonstrated that STAT3 knockdown promoted sorafenib-induced ER stress-induced apoptosis. Importantly, the DNA released by dead HCC cells stimulated the cGAS-STING signaling pathway in CD103⁺ DCs and promoted type I interferon production, thus, enhancing the anti-tumor function of CD8⁺ T and NK cells. In conclusion, our results revealed that the combination strategy of sorafenib and STAT3 knockdown might be a potential treatment strategy for HCC, directly and efficiently disturbing the tumor features of HCC cells while improving the tumor microenvironment via the cGAS-STING-Type I IFNs axis of DCs, inducing anti-HCC immune responses.

Iron Oxide Nanoparticles Functionalized with Fucoidan: a Potential Theranostic Nanotool for Hepatocellular Carcinoma

Fucoidan is a natural sulfated polysaccharide with a large range of biological activities including anticancer and anti-oxidation activities. Hepatocellular carcinoma is the fourth most common aggressive cancer type. The aim of this study was to investigate the bioactivity of free fucoidan versus its vectorization using nanoparticles (NPs) in human hepatoma cells, Huh-7. Iron oxide NPs were functionalized with fucoidan by a one-step surface complexation. NP cellular uptake was quantified by magnetic measurement at various extracellular iron concentrations. Cell invasion and migration were reduced with NPs while free fucoidan increases these events at low fucoidan concentration (≤ 0.5 mM). Concomitantly, a high decrease of reactive oxygen species production related with a decrease of the matrix metalloproteinase-9 activity and an increase of its expression was observed with NPs compared to free fucoidan. A proteomic analysis evidenced that some fucoidan regulated proteins appeared related to protein synthesis, N-glycan processing, and cellular stress. To our knowledge, this is the first study which reveals such activity induced by fucoidan. These results pave the way for USPIO-fucoidan-NPs as potential theranostic nanotool for hepatocellular carcinoma treatment.

Novel Paired Cell Lines for the Study of Lipid Metabolism and Cancer Stemness of Hepatocellular Carcinoma

There are few well-characterized syngeneic murine models for hepatocellular carcinoma (HCC), which limits immunological studies and the development of immunotherapies for HCC. We previously established an oncogene-induced spontaneous HCC mouse model based on transposon-mediated oncogene (AKT and NRASV12) insertion into the genome of hepatocytes to induce tumorigenesis. Two tumor clones with different levels of lipid droplets (LDs) showed similar in vitro growth but distinctive in vivo phenotypes, including divergent proliferative capability and varying induction of myeloid-derived suppressor cells (MDSCs). The two clones showed distinct gene expression related to lipid metabolism, glycolysis, and cancer stemness. Endogenous fatty acid (FA) synthesis and exogenous monounsaturated fatty acid (MUFA) consumption promoted both tumor proliferation and cancer stemness, and upregulated c-Myc in the HCC cell lines. Moreover, the LD^hi HCC cell line expressed a higher level of type II IL-4 receptor, which promoted tumor proliferation through binding IL-4 or IL-13. The chromosomal DNA of two tumor clones, NHRI-8-B4 (LD^hi) and NHRI-1-E4 (LD^lo) showed five identical AKT insertion sites in chromosomes 9, 10, 13, 16 and 18 and two NRAS integration sites in chromosomes 2 and 3. Herein, we describe two novel HCC cell lines with distinct features of lipid metabolism related to cancer stemness and differential interplay with the immune system, and present this syngeneic HCC mouse model as a practical tool for the study of cancer stemness and discovery of new therapies targeting liver cancers.

Clusterin and Related Scoring Index as Potential Early Predictors of Response to Sorafenib in Hepatocellular Carcinoma

Advanced hepatocellular carcinoma (HCC) remains a highly lethal malignancy, although several systemic therapeutic options are available, including sorafenib (SFN), which has been one of the standard treatment agents for almost a decade. As early prediction of response to SFN remains challenging, biomarkers that enable early prediction using a clinically feasible method are needed. Here, we report that the serum secretory form of clusterin (sCLU) protein and its related predictive index are potential beneficial biomarkers for early prediction of SFN response. Using high-throughput screening and subsequent multivariate analysis in the derivation cohort, we found that changes in the concentrations of CLU, vascular cell adhesion molecule-1 (VCAM1), and α-fetoprotein were significantly associated with response to SFN. Furthermore, we confirmed that an increase in CLU serum level 1 month after treatment initiation was significantly associated with shorter progression-free survival. In addition, "NR-index," which comprises these proteins, was evaluated as a tool for accurately predicting the efficacy of SFN and confirmed in the validation cohort. We also established SFN-resistant HepG2 cells (HepG2-SR) and found that sCLU significantly increased in HepG2-SR cells compared with normal HepG2 cells, and confirmed that HepG2-SR cells treated with SFN were resistant to apoptosis. The mechanism underlying activation of sCLU expression in acquired SFN resistance involves aberrant signaling and expression of Akt, mammalian target of rapamycin (mTOR), and a nutrient-related transcription factor, sterol regulatory element binding protein 1c (SREBP-1c). Furthermore, the PI3K and mTOR inhibitor BEZ235 markedly decreased sCLU expression in HepG2-SR cells. Conclusion: These results suggest that measurement of sCLU serum levels and the sCLU-related NR-index are promising clinical tools for the early prediction of SFN response in HCC. Additionally, sCLU-overexpressing HCC might be susceptible to mTOR inhibition.

Evaluating the Effects of Separate and Concomitant Use of MK-2206 and Salinomycin on Prostate Cancer Cell Line

Background

Prostate cancer is known as one of the most prevalent health disorders in the male population globally. The aim of the current study was to evaluate the effects of separate and concomitant use of MK-2206 and salinomycin on prostate cancer cell line.

Methods

The antitumor potential of separate and concomitant use of MK-2206 and salinomycin was evaluated in a panel of prostate cancer cell line (PC-3). To get insights into the underlying mechanism of action, different assays including the rate of apoptosis, cell viability, and gene expression were performed in treated prostate cancer cells.

Results

A significant reduction was detected in the viability percentage of prostate cancer cells (p< 0.001) and the rate of Akt expression (p< 0.001) in all salinomycin, MK-2206, and salinomycin+MK-2206 groups compared to the negative control group. Furthermore, in comparison with the negative control group, there was a notable increase in both the rate of Bad expression (p< 0.001) and prostate cancer cells apoptosis after salinomycin, MK-2206, and salinomycin+MK-2206 treatments. Moreover, the concomitant use of salinomycin+MK-2206 revealed synergistic improvements regarding the viability of prostate cancer cells and the rate of the Akt and Bad expressions compared to the separate administration of salinomycin and MK-2206 (all p< 0.05).

Conclusion

The findings of the present study may contribute to improving the efficacy of the therapies regarding the management of prostate cancer and providing a beneficial strategy in clinical trials.

Rescuing SLAMF3 Expression Restores Sorafenib Response in Hepatocellular Carcinoma Cells through the Induction of Mesenchymal-to-Epithelial Transition

Background: Acquired resistance to sorafenib in hepatocellular carcinoma (HCC) patients results in poor prognosis. Epithelial-to-mesenchymal transition (EMT) is the major mechanism implicated in the resistance to sorafenib. We have reported the tumor suppressor role of SLAMF3 (signaling lymphocytic activation molecules family 3) in HCC progression and highlighted its implication in controlling the MRP-1 transporter activity. These data suggest the implication of SLAMF3 in sorafenib resistance mechanisms. Methods: We evaluated the resistance to sorafenib in Huh-7 cells treated with progressive doses (Res cells). We investigated the link between acquired resistance to sorafenib and SLAMF3 expression by flow cytometry and Western blot methods. Furthermore, we analyzed the EMT and the stem cell potential of cells resistant to sorafenib. Results: Sorafenib resistance was confirmed in Res cells by analyzing the cell viability in the presence of sorafenib. The mesenchymal transition, in Res cells, was confirmed by high migratory index and the expression of EMT antigens. Interestingly, we found that loss of SLAMF3 expression corresponded to sorafenib-resistant phenotypes. The overexpression of SLAMF3 reversed EMT, decreased metastatic potential and inhibited mTOR/ERK1/2 in Res cells. Conclusions: We propose that rescuing SLAMF3 expression in resistant cells could represent a potential therapeutic strategy to enhance sorafenib efficacy in HCC patients.

Mechanisms of Pharmacoresistance in Hepatocellular Carcinoma: New Drugs but Old Problems

Hepatocellular carcinoma (HCC) is a malignancy with poor prognosis when diagnosed at advanced stages in which curative treatments are no longer applicable. A small group of these patients may still benefit from transarterial chemoembolization. The only therapeutic option for most patients with advanced HCC is systemic pharmacological treatments based on tyrosine kinase inhibitors (TKIs) and immunotherapy. Available drugs only slightly increase survival, as tumor cells possess additive and synergistic mechanisms of pharmacoresistance (MPRs) prior to or enhanced during treatment. Understanding the molecular basis of MPRs is crucial to elucidate the genetic signature underlying HCC resistome. This will permit the selection of biomarkers to predict drug treatment response and identify tumor weaknesses in a personalized and dynamic way. In this article, we have reviewed the role of MPRs in current first-line drugs and the combinations of immunotherapeutic agents with novel TKIs being tested in the treatment of advanced HCC.

Integrated Transcriptomic Analysis Revealed Hub Genes and Pathways Involved in Sorafenib Resistance in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), a high mortality malignancy, has become a worldwide public health concern. Acquired resistance to the multikinase inhibitor sorafenib challenges its clinical efficacy and the survival benefits it provides to patients with advanced HCC. This study aimed to identify critical genes and pathways associated with sorafenib resistance in HCC using integrated bioinformatics analysis. Differentially expressed genes (DEGs) were identified using four HCC gene expression profiles (including 34 sorafenib-resistant and 29 sorafenib-sensitive samples) based on the robust rank aggregation method and R software. Gene ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool. A protein–protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes (STRING), and small molecules reversing sorafenib resistance were searched for using the connectivity map (CMAP) database. Pearson correlation and survival analyses of hub genes were performed using cBioPortal and Gene Expression Profiling and Interactive Analysis (GEPIA). Finally, the expression levels of hub genes in sorafenib-resistant HCC cells were verified using quantitative polymerase chain reaction (q-PCR). A total of 165 integrated DEGs (66 upregulated and 99 downregulated in sorafenib resistant samples compared sorafenib sensitive ones) primarily enriched in negative regulation of endopeptidase activity, extracellular exosome, and protease binding were identified. Some pathways were commonly shared between the integrated DEGs. Seven promising therapeutic agents and 13 hub genes were identified. These findings provide a strategy and theoretical basis for overcoming sorafenib resistance in HCC patients.

Aberrant expression of PI3K/AKT signaling is involved in apoptosis resistance of hepatocellular carcinoma

Phosphatidylinositol 3-kinase (PI3K)/AKT signaling is a crucial pathway for cell survival and proliferation, which are regulated by several growth factors and activated receptors. Upregulated PI3K/AKT signaling molecules were reported in several cancers and they are associated with altered cellular functions, leading to oncogenesis. Here, we have examined the implications of elevated PI3K/AKT expression in the apoptosis resistance of human hepatocellular carcinoma (HCC) Huh7 cells. We showed that PI3K/AKT signaling is significantly upregulated in Huh7 cells by quantitative polymerase chain reaction and protein expression analysis. Also, perversely upregulated PI3K/AKT signaling Huh7 cells are highly resistant to treatment with chemotherapy drugs (docetaxel and sorafenib) and acquired apoptosis resistance through downregulation of tumor suppressor protein PTEN (phosphatase and tensin homolog deleted on chromosome ten). Hence, we have investigated the effect of PTEN overexpression on apoptosis induction in Huh7 cells. We showed that PTEN overexpressed Huh7 cells became more sensitive toward the aforesaid drugs and induced apoptotic cell death due to intracellular reactive oxygen species (ROS) generation. Concurrently, the overexpression of PTEN leads to the activation of mitochondria facilitated intrinsic apoptosis, evidenced by upregulated cytochrome C, caspase 3, and caspase 9. Collectively, our data suggest that the aberrant expression of PI3K/AKT signaling contributes to apoptosis resistance in HCC.

Anti-Hepatocellular Carcinoma Biomolecules: Molecular Targets Insights

This report explores the available curative molecules directed against hepatocellular carcinoma (HCC). Limited efficiency as well as other drawbacks of existing molecules led to the search for promising potential alternatives. Understanding of the cell signaling mechanisms propelling carcinogenesis and driven by cell proliferation, invasion, and angiogenesis can offer valuable information for the investigation of efficient treatment strategies. The complexity of the mechanisms behind carcinogenesis inspires researchers to explore the ability of various biomolecules to target specific pathways. Natural components occurring mainly in food and medicinal plants, are considered an essential resource for discovering new and promising therapeutic molecules. Novel biomolecules normally have an advantage in terms of biosafety. They are also widely diverse and often possess potent antioxidant, anti-inflammatory, and anti-cancer properties. Based on quantitative structure-activity relationship studies, biomolecules can be used as templates for chemical modifications that improve efficiency, safety, and bioavailability. In this review, we focus on anti-HCC biomolecules that have their molecular targets partially or completely characterized as well as having anti-cancer molecular mechanisms that are fairly described.

Traditional Chinese medicine for prevention and treatment of hepatocellular carcinoma: A focus on epithelial-mesenchymal transition

Hepatocellular carcinoma (HCC) is one of the most prevalent malignant cancers worldwide. Epithelial-mesenchymal transition (EMT), which endows epithelial cells with mesenchymal properties, plays an important role in the early stages of metastasis. Conventional cancer therapies have promising effects, but issues remain, such as high rates of metastasis and drug resistance. Thus, exploring and evaluating new therapies is an urgent need. Traditional Chinese medicines (TCMs) have been acknowledged for their multi-target and coordinated intervention effects against HCC. Accumulating evidence indicates that TCM can inhibit the malignancy of cells and the progression of EMT in HCC. However, studies on the effects of TCM on EMT in HCC are scarce. In this review, we summarized recent developments in anti-EMT TCMs and formulae, focusing on their underlying pharmacological mechanisms, to provide a foundation for further research on the exact mechanisms through which TCM affects EMT in HCC.

Metformin and Dichloroacetate Suppress Proliferation of Liver Cancer Cells by Inhibiting mTOR Complex 1

The Warburg effect is important for cancer cell proliferation. This phenomenon can be flexible by interaction between glycolysis and mitochondrial oxidation for energy production. We aimed to investigate the anticancer effects of the pyruvate dehydrogenase kinase inhibitor, dichloroacetate (DCA) and the mitochondrial respiratory complex I inhibitor metformin in liver cancer cells. The anticancer effect of DCA and/or metformin on HepG2, PLC/PRF5 human liver cancer cell lines, MH-134 murine hepatoma cell lines, and primary normal hepatocytes using MTT assay. Inhibition of lactate/ATP production and intracellular reactive oxygen species generation by DCA and metformin was investigated. Inhibition of PI3K/Akt/mTOR complex I was evaluated to see whether it occurred through AMPK signaling. Anticancer effects of a combination treatment of DCA and metformin were evaluated in HCC murine model. The results showed that metformin and DCA effectively induced apoptosis in liver cancer cells. A combination treatment of metformin and DCA did not affect viability of primary normal hepatocytes. Metformin upregulated glycolysis in liver cancer cells, thereby increasing sensitivity to the DCA treatment. Metformin and DCA inhibited mTOR complex I signaling through upregulated AMPK-independent REDD1. In addition, metformin and DCA increased reactive oxygen species levels in liver cancer cells, which induced apoptosis. A combination treatment of metformin and DCA significantly suppressed the tumor growth of liver cancer cells using in vivo xenograft model. Taken together, the combined treatment of metformin and DCA suppressed the growth of liver cancer cells. This strategy may be effective for patients with advanced liver cancer.

The selective serotonin reuptake inhibitors enhance the cytotoxicity of sorafenib in hepatocellular carcinoma cells

Sertraline and fluoxetine are the two most commonly used selective serotonin reuptake inhibitors (SSRIs) in the treatment of depression. Accumulating evidence has revealed that SSRIs can reduce the risk of hepatocellular carcinoma (HCC), but their therapeutic effects in HCC have not yet been elucidated. Previous studies have reported that sertraline and fluoxetine can suppress the growth of gastric carcinoma, melanoma and nonsmall cell lung cancers by inhibiting the mammalian target rapamycin (mTOR) activity. In this study, we found that sertraline and fluoxetine blocked the protein kinase B (AKT)/mTOR pathway and suppressed the growth of HCC cells in vitro, in xenografts and in diethylnitrosamine/carbon tetrachloride (DEN/CCL4)-induced primary liver mouse model. Sertraline and fluoxetine can synergize with sorafenib, the first approved standard therapy for advanced HCC, to inhibit the viability of HCC cells in vitro and in vivo. In addition, the combination of sorafenib and SSRIs synergistically inhibited the effects of the AKT/mTOR pathway. These results reveal novel therapeutic effects of a combination of SSRIs and sorafenib in HCC.

eIF4E-eIF4G complex inhibition synergistically enhances the effect of sorafenib in hepatocellular carcinoma

The clinical efficacy of sorafenib in hepatocellular carcinoma (HCC) is disappointing due to its low response rate and high rates of adverse effects. The eukaryotic translation initiation factor 4F (eIF4F) complex, mainly consisting of eIF4E-eukaryotic translation initiation factor 4G (eIF4G) interaction, is involved in the induction of drug resistance. Herein, we aimed to demonstrate that eIF4E-eIF4G complex inhibition enhanced the effect of sorafenib. The antiproliferation effect of combined treatment was evaluated by MTT assay and colony formation assay. Flow cytometry was used to detect the early cell apoptosis and cell cycle. The specific mechanism was demonstrated using western blot and lentivirus transfection. The combination of sorafenib with eIF4E-eIF4G inhibitors 4E1RCat (structural) or 4EGI-1 (competitive) synergistically inhibited the cell viability and colony formation ability of HCC cells. Moreover, the combined treatment induced more early apoptosis than sorafenib alone through downregulating the Bcl-2 expression. Besides, the coadministration of sorafenib and 4E1RCat or 4EGI-1 synergistically inhibited the expressions of eIF4E, eIF4G and phospho-4E-BP1 in HCC cells while blocking the phosphorylation of 4E-BP1 with lentiviral transfection failed to increase the sensitivity of HCC cells to sorafenib treatment. PI3K-AKT-mTOR signaling was also inhibited by the combined treatment. In a word, eIF4E-eIF4G complex inhibition synergistically enhances the effect of sorafenib in HCC treatment.

Y-box binding protein 1 augments sorafenib resistance via the PI3K/Akt signaling pathway in hepatocellular carcinoma

BACKGROUND

Sorafenib is the first-line treatment for patients with advanced hepatocellular carcinoma (HCC). Y-box binding protein 1 (YB-1) is closely correlated with tumors and drug resistance. However, the relationship between YB-1 and sorafenib resistance and the underlying mechanism in HCC remain unknown.

AIM

To explore the role and related mechanisms of YB-1 in mediating sorafenib resistance in HCC.

METHODS

The protein expression levels of YB-1 were assessed in human HCC tissues and adjacent nontumor tissues. Next, we constructed YB-1 overexpression and knockdown hepatocarcinoma cell lines with lentiviruses and stimulated these cell lines with different concentrations of sorafenib. Then, we detected the proliferation and apoptosis in these cells by terminal deoxynucleotidyl transferase dUTP nick end labeling, flow cytometry and Western blotting assays. We also constructed a xenograft tumor model to explore the effect of YB-1 on the efficacy of sorafenib in vivo. Moreover, we studied and verified the specific molecular mechanism of YB-1 mediating sorafenib resistance in hepatoma cells by digital gene expression sequencing (DGE-seq).

RESULTS

YB-1 protein levels were found to be higher in HCC tissues than in corresponding nontumor tissues. YB-1 suppressed the effect of sorafenib on cell proliferation and apoptosis. Consistently, the efficacy of sorafenib in vivo was enhanced after YB-1 was knocked down. Furthermore, KEGG pathway enrichment analysis of DGE-seq demonstrated that the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was essential for the sorafenib resistance induced by YB-1. Subsequently, YB-1 interacted with two key proteins of the PI3K/Akt signaling pathway (Akt1 and PIK3R1) as shown by searching the BioGRID and HitPredict websites. Finally, YB-1 suppressed the inactivation of the PI3K/Akt signaling pathway induced by sorafenib, and the blockade of the PI3K/Akt signaling pathway by LY294002 mitigated YB-1-induced sorafenib resistance.

CONCLUSION

Overall, we concluded that YB-1 augments sorafenib resistance through the PI3K/Akt signaling pathway in HCC and suggest that YB-1 is a key drug resistance-related gene, which is of great significance for the application of sorafenib in advanced-stage HCC.

Targeting Na+ /K+ -ATPase by berbamine and ouabain synergizes with sorafenib to inhibit hepatocellular carcinoma

BACKGROUND AND PURPOSE

The multikinase inhibitor sorafenib is a first-line drug for advanced hepatocellular carcinoma. The response to sorafenib varies among hepatocellular carcinoma patients and many of the responders suffer from reduced sensitivity after long-term treatment. This study aims to explore a novel strategy to potentiate or maximize the anti-hepatocellular carcinoma effects of sorafenib.

EXPERIMENTAL APPROACH

We used hepatocellular carcinoma cell lines, western blotting, various antagonists, siRNA and tumour xenografts mouse model to determine the anti- hepatocellular carcinoma effects of sorafenib in combination with berbamine or other Na⁺ /K⁺ -ATPase ligands.

KEY RESULTS

Berbamine and the cardiotonic steroid, ouabain, synergize with sorafenib to inhibit hepatocellular carcinoma cells growth. Mechanistically, berbamine induces Src phosphorylation in Na⁺ /K⁺ -ATPase-dependent manner, leading to the activation of p38MAPK and EGFR-ERK pathways. The Na⁺ /K⁺ -ATPase ligand ouabain also induces Src, EGFR, type I insulin-like growth factor receptor, ERK1/2 and p38MAPK phosphorylation in hepatocellular carcinoma cells. Treatment of hepatocellular carcinoma cells with Src or EGFR inhibitor inhibits the induction of ERK1/2 phosphorylation by berbamine. Moreover, sorafenib inhibits the induction of Src, p38MAPK, EGFR and ERK1/2 phosphorylation by berbamine and ouabain. Importantly, combination of sorafenib with berbamine or ouabain synergistically inhibits both sorafenib-naïve and sorafenib-resistant hepatocellular carcinoma cells growth. Co-treatment of hepatocellular carcinoma cells with berbamine and sorafenib significantly induces cell death and significantly inhibits hepatocellular carcinoma xenografts growth in vivo.

CONCLUSION AND IMPLICATIONS

Berbamine or other Na⁺ /K⁺ -ATPase ligands have a potential for improving sorafenib responsiveness in hepatocellular carcinoma. Targeting Na⁺ /K⁺ -ATPase represents a novel strategy to potentiate the anti- hepatocellular carcinoma effects of sorafenib.

3-hydroxyanthranic acid increases the sensitivity of hepatocellular carcinoma to sorafenib by decreasing tumor cell stemness

Sorafenib is the FDA-approved first-line target drug for HCC patients. However, sorafenib only confers 3–5 months of survival benefit with <30% of HCC patients. Thus, it is necessary to develop a sensitizer for hepatocellular carcinoma (HCC) to sorafenib. Here, we report that in representative HCC cell lines (SMMC-7721 and PLC8024) that are insensitive to sorafenib, 3-HAA (50 μM) significantly enhances cell sensitivity to sorafenib to an extent that could not be explained by additive effects. In nude mice carrying HCC xenograft, tumor growth is inhibited by sorafenib (10 mg/kg/day) or 3-HAA (100 mg/kg/day) alone. When used in combination, the treatment effectively prevents the xenograft from growing. In a set of mechanistic experiments, we find enhanced AKT activation and increased proportion of CD44⁺CD133⁺ cells in sorafenib-resistant HCC cells and tissues. The proportion of CD44⁺CD133⁺ cells is reduced upon 3-HAA treatment in both cultured cells and mouse xenografts, suggesting that 3-HAA could decrease the stemness of HCC. We also detect decreased phosphorylation of AKT, a regulator of the GSK3β/β-catenin signaling upon 3-HAA treatment. The AKT activator SC79 activates GSK3 β/β-catenin signaling while the Wnt inhibitor XAV-939 abolishes 3-HAA inhibition of HCC growth in vitro and in mice. The current study demonstrates that 3-HAA sensitizes HCC cells to sorafenib by reducing tumor stemness, suggesting it is a promising molecule for HCC therapy.

Elucidating the Molecular Basis of Sorafenib Resistance in HCC: Current Findings and Future Directions

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide. Sorafenib is the first multi-tyrosine kinase inhibitor approved for HCC and it has represented the standard of care for advanced HCC for almost 10 years, offering a survival benefit when compared to placebo. However, this benefit is limited, showing rare objective responses and a disease control rate approaching 50–60%, with most patients experiencing disease progression at 6 months. These scant results dictate the urgent need for strategies to overcome both primary and acquired resistance. Herein we report several mechanisms supporting resistance to sorafenib in HCC patients, including activation of oncogenic pathways. Among these, the AKT/mTOR pathway plays a crucial role being at the crossroad of multiple driving events. Autophagy, multidrug-resistant phenotype, hypoxia-related mechanisms and endoplasmic reticulum stress are gaining more and more relevance as crucial events driving the response to anticancer drugs, including sorafenib. Several HCC-specific miRNAs take part to the regulation of these cellular processes. Remarkably, molecularly targeted strategies able to overcome resistance in these settings have also been reported. So far, the vast majority of data has been derived from laboratory studies, which means the need for an extensive validation. Indeed, most of the possible drug associations displaying promising effects in improving sorafenib efficacy herein described derive from preclinical explorations. Notably, data obtained in animal models can be inconsistent with regard to the human disease for efficacy, safety, side effects, best formulation and pharmacokinetics. However, they represent the necessary preliminary step to improve the management of advanced HCC.

The Endless Sources of Hepatocellular Carcinoma Heterogeneity

Simple Summary

Tumor heterogeneity in liver cancer is a major contributor to the high lethality rate found in patients suffering from this disease. The therapeutic outcomes are drastically affected by this heterogeneity, which complicates patient stratification and response prediction. Better understanding of all the factors that can contribute to this heterogeneity will be critical to improve our understanding of liver cancer, in order to optimize the outcome of patients.

Abstract

Hepatocellular carcinoma (HCC) represents a global health problem. The incidence keeps increasing and current therapeutic options confer limited benefits to the patients. Tumor heterogeneity plays a central role in this context, limiting the availability of predictive biomarkers and complicating the criteria used to choose the most suitable therapeutic option. HCC heterogeneity occurs at different levels: within the population (inter-patient heterogeneity) and within tumors from the same patient (intra-patient and intra-tumor heterogeneity). Experts in the field have made many efforts to classify the patients based on clinicopathological characteristics and molecular signatures; however, there is still much work ahead to be able to integrate the extra-tumor heterogeneity that emerges from the complexity of the tumor microenvironment, which plays a critical role in the pathogenesis of the disease and therapy responses. In this review, we summarize tumor intrinsic and extrinsic sources of heterogeneity of the most common etiologies of HCC and summarize the most recent discoveries regarding the evolutionary trajectory of liver cancer cells and the influence of tumor-extrinsic factors such as the microbiome and the host immune system. We further highlight the potential of novel high-throughput methodologies to contribute to a better understanding of this devastating disease and to the improvement of the clinical management of patients.

Circular RNA hsa_circ_0003288 induces EMT and invasion by regulating hsa_circ_0003288/miR-145/PD-L1 axis in hepatocellular carcinoma

Background

Epithelial-mesenchymal transition (EMT) has been associated with wound healing, tumorigenesis, and metastasis. Circular RNAs (circRNAs) are functional non-coding RNAs involved in multiple human cancers. However, whether and how circRNAs contribute to the EMT in hepatocellular carcinomas (HCC) remains to be deciphered. In this study, we investigated the regulation and function of hsa_circ_0003288 on programmed death-1 ligand 1 (PD-L1) during EMT and HCC invasiveness.

Methods

Hsa_circ_0003288 expression was measured by real-time quantitative reverse transcriptase PCR (qRT-PCR). Luciferase reporter assays, RNA pull-down assay and fluorescence in situ hybridization (FISH) were used to determine the correlation between hsa_circ_0003288 and miR-145 and between miR-145 and PD-L1. Furthermore, ectopic overexpression and siRNA-mediated downregulation of hsa_circ_0003288, transwell assays, and in vivo studies were used to determine the function of hsa_circ_0003288 on the EMT and invasiveness of L02 and HCC cells.

Results

miR-145 directly targeted the PD-L1 3′-untranslated region (UTR) region, and hsa_circ_0003288 acted as a miR-145 sponge to regulate PD-L1 expression. Overexpression of hsa_circ_0003288 increased PD-L1 levels and promoted EMT, migration, and invasiveness of L02 cells. These observations were reversed after knockdown of hsa_circ_0003288 in HepG2 and Huh7 cells. Overexpression of PD-L1 rescued EMT, migration, and invasiveness of HepG2 and Huh7 cells after knockdown of hsa_circ_0003288. Furthermore, hsa_circ_0003288 knockdown reduced EMT in in vivo studies. Hsa_circ_0003288/PD-L1 axis was found to mediate the metastatic phenotypes via the PI3K/Akt pathway in HCC. Additionally, expression levels of hsa_circ_0003288 were increased and positively correlated with PD-L1 expression in HCC tissues.

Conclusion

Our findings demonstrated that hsa_circ_0003288 promoted EMT and invasion of HCC via the hsa_circ_0003288/miR-145/PD-L1 axis through the PI3K/Akt pathway. Targeting hsa_circ_0003288 may be a therapeutic strategy for the treatment of HCC.

LncRNA HOTAIR contributes Taxol-resistance of hepatocellular carcinoma cells via activating AKT phosphorylation by down-regulating miR-34a

Drug resistance of Taxol leads to the treatment failure in hepatocellular carcinoma (HCC). LncRNA HOTAIR have drawn increasing attention in various diseases; its function and mechanism in Taxol-resistance in HCC remain unclear. In the present study, the two Taxol resistant HCC cell lines (HepG2/Taxol and SMMC7721/Taxol) were induced. The qRT-PCR data exhibited that over-expressed HOTAIR as well as low-expressed miR-34a were founded in HepG2/Taxol and SMMC7721/Taxol cells. HOTAIR knockdown suppresses proliferation, invasion and promotes apoptosis of in HepG2/Taxol and SMMC7721/Taxol cells through up-regulating miR-34a by MTT assay, transwell invasion assays and flow cytometry, while down-regulation of miR-34a had an opposite effect on reversing Taxol resistance. Cleaved caspase-3 and Bax were significantly up-regulated by si-HOTAIR transfection, while Bcl-2 level exhibited opposite trend. Besides, HOTAIR knockdown impaired Taxol-resistance in HCC by accommodating Akt phosphorylation and Wnt/β-catenin signaling via interacting with miR-34a. The present study may afford a valuable target for treating Taxol-resistance in HCC.

Role of Alpha-Fetoprotein in Hepatocellular Carcinoma Drug Resistance

Hepatocellular carcinoma (HCC) is a major type of primary liver cancer and a major cause of cancer-related deaths worldwide because of its high recurrence rate and poor prognosis. Surgical resection is currently the major treatment measure for patients in the early and middle stages of the disease. Because due to late diagnosis, most patients already miss the opportunity for surgery upon disease confirmation, conservative chemotherapy (drug treatment) remains an important method of comprehensive treatment for patients with middle- and late-stage liver cancer. However, multidrug resistance (MDR) in patients with HCC severely reduces the treatment effect and is an important obstacle to chemotherapeutic success. Alpha-fetoprotein (AFP) is an important biomarker for the diagnosis of HCC. The serum expression levels of AFP in many patients with HCC are increased, and a persistently increased AFP level is a risk factor for HCC progression. Many studies have indicated that AFP functions as an immune suppressor, and AFP can promote malignant transformation during HCC development and might be involved in the process of MDR in patients with liver cancer. This review describes drug resistance mechanisms during HCC drug treatment and reviews the relationship between the mechanism of AFP in HCC development and progression and HCC drug resistance.

Design, synthesis and biological evaluation of a new thieno[2,3-d]pyrimidine-based urea derivative with potential antitumor activity against tamoxifen sensitive and resistant breast cancer cell lines

Breast cancer (BC) and endocrine resistance to chemotherapy are challenging problems where angiogenesis plays fundamental roles. Thus, targeting of VEGFR-2 signalling pathway has been an attractive approach. In this study, we synthesised a new sorafenib analogue, thieno[2,3-d]pyrimidine based urea derivative, KM6. It showed 65% inhibition of VEGF2 tyrosine kinase activity and demonstrated a potential antitumor activity in TAM-resistant, LCC2, and its parental MCF7 BC cells. KM6 retained the sensitivity of LCC2 through upregulation of key enzymes of apoptosis and proteins of cell death including caspases 3, 8, 9, P53, BAX/BCL-2 ratio and LDH in media. It downregulated mRNA expression of Ki-67, survivin, Akt, and reduced levels of ROS and glucose uptake. Moreover, KM6 reduced the levels of inflammation markers PGE2, COX2, IL-1β and IL6 and metastasis markers MMP-2 and MMP-9. In conclusion, KM6 is a promising compound for ER + and TAM-resistant BC with many potential antitumor and polypharmacological mechanisms.

The kynurenine derivative 3-HAA sensitizes hepatocellular carcinoma to sorafenib by upregulating phosphatases

Objectives: Sorafenib is the only FDA-approved first-line target drug for HCC patients. However, sorafenib merely confers 3-5 months of survival benefit with less than 30% of HCC patients sensitive to sorafenib therapy. Thus, it's necessary to develop a sensitizer for hepatocellular carcinoma (HCC) to sorafenib. Methods: The principal component analysis, gene ontology, and KEGG analysis are utilized following RNA-sequencing. The mass spectrometry analysis following immunoprecipitation is performed to discover the phosphatase targets. Most importantly, both the cell line-derived xenograft (CDX) and the patient-derived xenograft (PDX) mouse model are used to determine the effect of 3-HAA on sorafenib-resistant HCC in vivo. Results: In nude mice carrying HCC xenograft, tumor growth is inhibited by sorafenib or 3-HAA alone. When used in combination, the treatment particularly prevents the xenograft from growing. Combined treatment also suppresses the growth of sorafenib-resistant (≥30mg/kg) PDXs. In a set of mechanistic experiments, we find enhanced AKT activation and decreased apoptotic cells in de novo and acquired sorafenib-resistant HCC cells and tissues. 3-HAA decreases AKT phosphorylation and increases the apoptosis of HCC in both cultured cells and mouse xenografts by upregulation of phosphatases PPP1R15A/DUSP6. PPP1R15A/PPP1α directly reduces Akt phosphorylation while DUSP6 decreases Akt activity through inhibiting PDK1. The AKT activator abolishes 3-HAA inhibition of HCC growth in vitro and in mice. Conclusion: This study demonstrates that 3-HAA sensitizes HCC cells to sorafenib by upregulation of phosphatases, suggesting it as a promising molecule for HCC therapy.

Hepatitis B virus induces sorafenib resistance in liver cancer via upregulation of cIAP2 expression

BACKGROUND

HBV promotes cell survival by upregulating the expression of the cellular inhibitor of apoptosis protein 2 (cIAP2), however whether it is involved in HBV-induced sorafenib resistance in liver cancer remains unclear.

METHODS

cIAP2 overexpression and knockdown was adopted to assess the involvement of cIAP2 in HBV-induced sorafenib resistance. Anti-HBV drug lamivudine and Akt inhibitor were used to investigate the impact of HBV replication on cIAP2 expression and sorafenib resistance. Xenotransplantation mouse model was used to confirm the data on cell lines in vitro.

RESULTS

Liver cancer cell line HepG2.215 showed increased cIAP2 expression and enhanced resistance to sorafenib. Upon sorafenib treatment, overexpression of cIAP2 in HepG2 lead to decreased cleaved caspase 3 level and increased cell viability, while knockdown of cIAP2 in HepG2.215 resulted in increased level of cleaved caspase 3 and decreased cell viability, suggesting the involvement of cIAP2 in HBV-induced sorafenib resistance. Furthermore, anti-HBV treatment reduced cIAP2 expression and partially restored sorafenib sensitivity in HepG2.215 cells. Xenotransplantation mouse model further confirmed that co-treatment with lamivudine and sorafenib could reduce sorafenib-resistant HepG2.215 tumor cell growth.

CONCLUSION

cIAP2 is involved in HBV-induced sorafenib resistance in liver cancer and anti-HBV treatments reduce cIAP2 expression and partially restore sorafenib sensibility.

Identification of Biomarkers Based on Bioinformatics Analysis: The Expression of Ubiquitin-Conjugating Enzyme E2T (UBE2T) in the Carcinogenesis and Progression of Hepatocellular Carcinoma

BACKGROUND The purpose of this study was to screen and identify key genes in the occurrence and development of hepatocellular carcinoma (HCC) based on bioinformatics analysis. MATERIAL AND METHODS Three Gene Expression Omnibus (GEO) series (GSE) - GSE121248, GSE87630, and GSE84598 - were downloaded from the GEO database. GEO2R was used to screen different genes and a Venn diagram was drawn to screen coexpressed differentially expressed genes (DEGs). Coexpressed DEGs were obtained by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, a protein-protein interaction network diagram was produced by Cytoscape, and module genes were calculated by the Molecular Complex Detection Cytoscape plug-in. Finally, overall survival, progression-free survival, and relapse-free survival analysis of the key genes selected were performed using the online Kaplan-Meier plotter. For the target genes, the online network UCSC Cancer Genome Browser was used to analyze the gene expression profiles of the grade and vascular invasion of HCC. RESULTS A total of 296 coexpressed DEGs were obtained from the 3 GSEs and 12 key genes were obtained from the modular analysis. Survival analysis showed that the upregulated genes UBE2T and FBLN5 were involved in the poor prognosis of HCC. Furthermore, the expression of UBE2T was significantly related to the grade and vascular invasion of HCC. CONCLUSIONS The expression of the UBE2T gene was significantly upregulated in HCC tissue compared to in normal liver tissue. UBE2T may be a new marker for the diagnosis and subsequent therapy of HCC.

Recent Advances in Multi-target Drugs Targeting Protein Kinases and Histone Deacetylases in Cancer Therapy

Protein Kinase Inhibitors (PKIs) and Histone Deacetylase Inhibitors (HDACIs) are two important classes of anticancer agents and have provided a variety of small molecule drugs for the treatment of various types of human cancers. However, malignant tumors are of a multifactorial nature that can hardly be "cured" by targeting a single target, and treatment of cancers hence requires modulation of multiple biological targets to restore the physiological balance and generate sufficient therapeutic efficacy. Multi-target drugs have attracted great interest because of their advantages in the treatment of complex cancers by simultaneously targeting multiple signaling pathways and possibly leading to synergistic effects. Synergistic effects have been observed in the combination of kinase inhibitors, such as imatinib, dasatinib, or sorafenib, with an array of HDACIs including vorinostat, romidepsin, or panobinostat. A considerable number of multi-target agents based on PKIs and HDACIs have been developed. In this review, we summarize the recent literature on the development of multi-target kinase-HDAC inhibitors and provide our view on the challenges and future directions on this topic.

LXRα activation and Raf inhibition trigger lethal lipotoxicity in liver cancer

The success of molecular therapies targeting specific metabolic pathways in cancer is often limited by the plasticity and adaptability of metabolic networks. Here we show that pharmacologically induced lipotoxicity represents a promising therapeutic strategy for the treatment of hepatocellular carcinoma (HCC). LXRα-induced liponeogenesis and Raf-1 inhibition are synthetic lethal in HCC owing to a toxic accumulation of saturated fatty acids. Raf-1 was found to bind and activate SCD1, and conformation-changing DFG-out Raf inhibitors could disrupt this interaction, thereby blocking fatty acid desaturation and inducing lethal lipotoxicity. Studies in genetically engineered and nonalcoholic steatohepatitis-induced HCC mouse models and xenograft models of human HCC revealed that therapies comprising LXR agonists and Raf inhibitors were well tolerated and capable of overcoming therapy resistance in HCC. Conceptually, our study suggests pharmacologically induced lipotoxicity as a new mode for metabolic targeting of liver cancer.