Oxidative stress and ERK1/2 phosphorylation as predictors of outcome in hepatocellular carcinoma patients treated with sorafenib plus octreotide LAR

Deciphering the immune modulation through deep transcriptomic profiling and therapeutic implications of DNA damage repair pattern in hepatocellular carcinoma

AIMS

DNA damage repair (DDR) plays a pivotal role in hepatocellular carcinoma (HCC), driving oncogenesis, progression, and therapeutic response. However, the mechanisms of DDR mediated immune cells and immuno-modulatory pathways in HCC are yet ill-defined.

METHODS

Our study introduces an innovative deep machine learning framework for precise DDR assessment, utilizing single-cell RNA sequencing (scRNA-seq) and bulk RNA-seq data. Single-cell RNA sequencing data were obtained and in total 85,628 cells of primary or post-immunotherapy cases were analyzed. Large-scale HCC datasets, including 1027 patients in house together with public datasets, were used for 101 machine-learning models and a novel DDR feature was derived at single-cell resolution (DDRscore). Druggable targets were predicted using the reverse phase protein array (RPPA) proteomic profiling of 169 HCC patients and RNA-seq data from 22 liver cancer cell lines.

RESULTS

Our investigation reveals a dynamic interplay of DDR with natural killer cells and B cells in the primary HCC microenvironment, shaping a tumor-promoting immune milieu through metabolic programming. Analysis of HCC post-immunotherapy demonstrates elevated DDR levels that induces epithelial-mesenchymal transition and fibroblast-like transformation, reshaping the fibrotic tumor microenvironment. Conversely, attenuated DDR promotes antigen cross-presentation by dendritic cells and CD8+ T cells, modulating the inflammatory tumor microenvironment. Regulatory network analysis identifies the CXCL10-CXCR3 axis as a key determinant of immunotherapeutic response in low DDR HCC, potentially regulated by transcription factors GATA3, REL, and TBX21. Using machine learning techniques by combining bulk RNA-seq data in house together with public datasets, we introduce DDRscore, a robust consensus DDR scoring system to predict overall survival and resistance to PD-1 therapy in HCC patients. Finally, we identify BRAF as a potential therapeutic target for high DDRscore patients.

CONCLUSION

Our comprehensive findings advance our understanding of DDR and the tumor microenvironment in HCC, providing insights into immune regulatory mechanisms mediated via DDR pathways.

Erk1/2-Dependent HNSCC Cell Susceptibility to Erastin-Induced Ferroptosis

Unfavorable clinical outcomes mean that cancer researchers must attempt to develop novel therapeutic strategies to overcome therapeutic resistance in patients with HNSCC. Recently, ferroptosis was shown to be a promising pathway possessing druggable targets, such as xCT (SLC7A11). Unfortunately, little is known about the molecular mechanisms underlying the susceptibility of HNSCC cells to ferroptosis. The goal of this study was to determine whether HNSCC cells with activated Erk1/2 are vulnerable to ferroptosis induction. Our results have shown that xCT (SLC7A11) was overexpressed in malignant tissues obtained from the patients with HNSCC, whereas normal mucosa demonstrated weak expression of the protein. In order to investigate the role of Erk1/2 in the decrease in cell viability caused by erastin, xCT-overexpressing FaDu and SCC25 HNSCC cells were used. The ravoxertinib-dependent inhibition of Erk1/2 signaling led to the decrease in erastin efficacy due to the effect on ROS production and the upregulation of ROS scavengers SOD1 and SOD2, resulting in repressed lipid peroxidation. Therefore, it was concluded that the erastin-dependent activation of ferroptosis seems to be a promising approach which can be further developed as an additional strategy for the treatment of HNSCC. As ferroptosis induction via erastin is strongly dependent on the expression of Erk1/2, this MAP kinase can be considered as a predictor for cancer cells' response to erastin.

Antitumoral and Anti-inflammatory Roles of Somatostatin and Its Analogs in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and affects about 8% of cirrhotic patients, with a recurrence rate of over 50%. There are numerous therapies available for the treatment of HCC, depending on cancer staging and condition of the patient. The complexity of the treatment is also justified by the unique pathogenesis of HCC that involves intricate processes such as chronic inflammation, fibrosis, and multiple molecular carcinogenesis events. During the last three decades, multiple in vivo and in vitro experiments have used somatostatin and its analogs (SSAs) to reduce the proliferative and metastatic potential of hepatoma cells by inducing their apoptosis and reducing angiogenesis and the inflammatory component of HCC. Most experiments have proven successful, revealing several different pathways and mechanisms corresponding to the aforementioned functions. Moreover, a correlation between specific effects and expression of somatostatin receptors (SSTRs) was observed in the studied cells. Clinical trials have tested either somatostatin or an analog, alone or in combination with other drugs, to explore the potential effects on HCC patients, in various stages of the disease. While the majority of these clinical trials exhibited minor to moderate success, some other studies were inconclusive or even reported negative outcomes. A complete evaluation of the efficacy of somatostatin and SSAs is still the matter of intense debate, and, if deemed useful, these substances may play a beneficial role in the management of HCC patients.

Omega-Class Glutathione Transferases of Carcinogenic Liver Fluke, Clonorchis sinensis, Modulate Apoptosis and Differentiation of Host Cholangiocytes

The small liver fluke Clonorchis sinensis causes hepatobiliary ductal infections in humans. Clonorchiasis is characterized histopathologically by ductal dysplasia, hyperplasia and metaplasia, which closely resembles cholangiocarcinoma (CCA). The disruption of programmed cell death is critical for malignant transformation, while molecular events underlying these phenomena have poorly been understood in clonorchiasis-related CCA tumorigenesis. We incorporated recombinant C. sinensis omega-class glutathione transferase (rCsGSTo) 1 or 2 into human intrahepatic biliary epithelial cells (HIBECs) and analyzed pathophysiological alterations of HIBECs upon the application of oxidative stress. rCsGSTos partially but significantly rescued HIBECs from cell death by inhibiting oxidative stress-induced apoptosis (p < 0.01). rCsGSTos modulated transcriptional levels of numerous genes. We analyzed 13 genes involved in programmed cell death (the upregulation of five antiapoptotic and two apoptotic genes, and the downregulation of one antiapoptotic and five apoptotic genes) and 11 genes associated with cell differentiation (the increase in seven and decrease in four genes) that showed significant modifications (p < 0.05). The induction profiles of the mRNA and proteins of these differentially regulated genes correlated well with each other, and mostly favored apoptotic suppression and/or cell differentiation. We detected increased active, phosphorylated forms of Src, PI3K/Akt, NF-κB p65, MKK3/6 and p38 MAPK, but not JNK and ERK1/2. CsGSTos were localized in the C. sinensis-infected rat cholangiocytes, where cytokeratin 19 was distributed. Our results demonstrated that CsGSTos excreted to the biliary lumen are internalized and accumulated in the host cholangiocytes. When cholangiocytes underwent oxidative stressful condition, CsGSTos appeared to be critically involved in both antiapoptotic process and the differentiation of host cholangiocytes through the regulation of target genes following the activation of responsible signal molecules.

Identification of DNA repair-related genes predicting pathogenesis and prognosis for liver cancer

Background

Liver cancer (LC) is one of the most fatal cancers throughout the world. More efficient and sensitive gene signatures that could accurately predict survival in LC patients are vitally needed to promote a better individualized and effective treatment.

Material/methods

422 LC and adjacent normal tissues with both RNA-Seq and clinical data in TCGA were embedded in our study. Gene set enrichment analysis (GSEA) was applied to identify genes and hallmark gene sets that are more valuable for liver cancer therapy. Cox regression analysis was used to identify genes related to overall survival (OS) and build the prediction model. cBioPortal database was used to examine the alterations of the panel mRNA signature. ROC curves and Kaplan–Meier curves were used to validate the prediction model. Besides, the expression of the genes in the model were validated using quantitative real-time PCR in clinical tissue specimens.

Results

The panel of DNA repair-related mRNA signature consisted of seven mRNAs: RFC4 (replication factor C subunit 4), ZWINT (ZW10 interacting kinetochore protein), UPF3B (UPF3B regulator of nonsense mediated mRNA decay), NCBP2 (nuclear cap binding protein subunit 2), ADA (adenosine deaminase), SF3A3 (splicing factor 3a subunit 3) and GTF2H1 (general transcription factor IIH subunit 1). On-line analysis of cBioPortal database found that the expression of the panel mRNA has a wide variation ranging from 7 to 10%. All the mRNAs were significantly upregulated in LC tissues compared to normal tissues (P < 0.05). The risk model is closely related to the OS of LC patients. The hazard ratio (HR) is 2.184 [95% CI (confidence interval) 1.523–3.132] and log-rank P-value < 0.0001. For clinical specimen validation, we found that all of the genes in the model upregulated in liver cancer tissues versus normal liver tissues, which was consistent with the results predicted.

Conclusions

Our study demonstrated a mRNA signature including seven mRNA for prognosis prediction of LC. This panel gene signature provides a new criterion for accurate diagnosis and therapeutic target of LC.

Prognostic Stratification Based on a Novel Nomogram for Solitary Large Hepatocellular Carcinoma After Curative Resection

Solitary large hepatocellular carcinoma (SLHCC) is a specific subtype of HCC with unique characteristics. It is of great interest to assess and stratify the prognosis of SLHCCs after curative resection. In this study, we tried to construct a prognostic nomogram for SLHCC following curative resection through a retrospective analysis of 202 SLHCC cases. Seven prognostic factors were identified and integrated to establish a novel prognostic nomogram, which included tumor size, microvascular invasion, tumor differentiation, Ki67 (%), α-fetoprotein (AFP), carbohydrate antigen 125 (CA125), and HBsAg status. The Harrell's concordance index (C-index) of the nomogram for overall survival (OS) in the training, validation, and whole sets was 0.752, 0.703, and 0.733, respectively. Furthermore, the area under the curve (AUC) of the receiver operating characteristic (ROC) curve of the nomogram for predicting 1-, 3-, and 5-year OS indicated that the nomogram had an optimal discrimination of the prognostic prediction for SLHCC. The total score of each patient was calculated based on the nomogram, and patients were divided into three subgroups: low-risk group (total score ≦ 107), medium-risk group (107 < total score ≤ 125), and high-risk group (total score > 125). The 1-, 3-, and 5-year OS rates of the low-risk, medium-risk, and high-risk groups in the whole set were 89.3 vs. 70.1 vs. 33.3%, 76.6 vs. 37.8 vs. 14.5%, and 69.8 vs. 25.1 vs. 12.5%, respectively (P < 0.001). Similar results were shown in terms of the recurrence-free survival (RFS) rate. By analyzing 101 cases of recurrent tumors, transarterial chemoembolization (TACE) plus radiofrequency ablation (RFA)/surgery was found to prolong patient survival when compared to TACE alone in the low-risk group, but not in the medium/high-risk group. In conclusion, our prognostic nomogram successfully stratifies the prognosis for SLHCC after curative resection, which deserves further study in future clinical practice.

lncRNA-POIR promotes epithelial-mesenchymal transition and suppresses sorafenib sensitivity simultaneously in hepatocellular carcinoma by sponging miR-182-5p

Sorafenib (SOR) resistance remains a major obstacle in the effective treatment of hepatocellular carcinoma (HCC). A number of long noncoding RNAs (lncRNAs) are responsible for this chemoresistance. This study aimed to reveal the essential function of a recently defined lncRNA, lncRNA-POIR, in the epithelial-mesenchymal transition (EMT) and SOR sensitivity of HCC cells. SOR-induced cytotoxicity was analyzed via cell counting kit-8 and ethynyl-2'-deoxyuridine incorporation assays, whereas immunoblotting and confocal immunofluorescence were used to determine the expression levels of EMT markers. Furthermore, loss- or gain-of-function approaches were used to demonstrate the role of lncRNA-POIR/miR-182-5p on EMT and SOR sensitivity in HCC. The direct interaction between lncRNA-POIR and miR-182-5p was verified using a luciferase reporter assay. We found that knockdown of lncRNA-POIR sensitized HCC cells to SOR and simultaneously reversed EMT. As expected, miR-182-5p was confirmed as the downstream target of lncRNA-POIR. Moreover, miR-182-5p overexpression clearly reversed EMT and promoted SOR-induced cytotoxicity in representative HCC cells, whereas miR-182-5p downregulation played a contrasting role; miR-182-5p knockdown abolished the modulatory effects of lncRNA-POIR siRNA on EMT and SOR sensitivity. Together, these pieces of data suggest that lncRNA-POIR promotes EMT progression and suppresses SOR sensitivity simultaneously by sponging miR-182-5p. Thus, we proposed a compelling rationale for the use of lncRNA-POIR as a promising predictor of SOR response and as a potential therapeutic target for HCC treatment in the future.

Dendrimer Nanodevices and Gallic Acid as Novel Strategies to Fight Chemoresistance in Neuroblastoma Cells

Human neuroblastoma (NB), a pediatric tumor inclined to relapse, after an initial response to therapy, usually develops resistance. Since several chemotherapeutics exert anticancer effect by increasing reactive oxygen species (ROS), NB cells overproduce antioxidant compounds becoming drugs-resistant. A strategy to sensitize NB cells to chemotherapy involves reducing their antioxidant defenses and inducing ROS overproduction. Concerning this, although affected by several issues that limit their clinical application, antioxidant/pro-oxidant polyphenols, such as gallic acid (GA), showed pro-oxidant anti-cancer effects and low toxicity for healthy cells, in several kind of tumors, not including NB. Herein, for the first time, free GA, two GA-dendrimers, and the dendrimer adopted as GA reservoir were tested on both sensitive and chemoresistant NB cells. The dendrimer device, administered at the dose previously found active versus sensitive NB cells, induced ROS-mediated death also in chemoresistant cells. Free GA proved a dose-dependent ROS-mediated cytotoxicity on both cell populations. Intriguingly, when administered in dendrimer formulations at a dose not cytotoxic for NB cells, GA nullified any pro-oxidant activity of dendrimer. Unfortunately, due to GA, nanoformulations were inactive on NB cells, but GA resized in nanoparticles showed considerable ability in counteracting, at low dose, ROS production and oxidative stress, herein induced by the dendrimer.

Integrated molecular signaling involving mitochondrial dysfunction and alteration of cell metabolism induced by tyrosine kinase inhibitors in cancer

Cancer cells have unlimited replicative potential, insensitivity to growth-inhibitory signals, evasion of apoptosis, cellular stress, and sustained angiogenesis, invasiveness and metastatic potential. Cancer cells adequately adapt cell metabolism and integrate several intracellular and redox signaling to promote cell survival in an inflammatory and hypoxic microenvironment in order to maintain/expand tumor phenotype. The administration of tyrosine kinase inhibitor (TKI) constitutes the recommended therapeutic strategy in different malignancies at advanced stages.

There are important interrelationships between cell stress, redox status, mitochondrial function, metabolism and cellular signaling pathways leading to cell survival/death. The induction of apoptosis and cell cycle arrest widely related to the antitumoral properties of TKIs result from tightly controlled events involving different cellular compartments and signaling pathways. The aim of the present review is to update the most relevant studies dealing with the impact of TKI treatment on cell function. The induction of endoplasmic reticulum (ER) stress and Ca²⁺ disturbances, leading to alteration of mitochondrial function, redox status and phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt)-mammalian target of rapamycin (mTOR) and AMP-activated protein kinase (AMPK) signaling pathways that involve cell metabolism reprogramming in cancer cells will be covered. Emphasis will be given to studies that identify key components of the integrated molecular pattern including receptor tyrosine kinase (RTK) downstream signaling, cell death and mitochondria-related events that appear to be involved in the resistance of cancer cells to TKI treatments.

Role of cellular, molecular and tumor microenvironment in hepatocellular carcinoma: Possible targets and future directions in the regorafenib era

Hepatocellular carcinoma (HCC) remains as one of the major causes of cancer-related mortality, despite the recent development of new therapeutic options. Regorafenib, an oral multikinase inhibitor, is the first systemic therapy that has a survival benefit for patients with advanced HCC that have a poor response to sorafenib. Even though regorafenib has been approved by the FDA, the clinical trial for regorafenib treatment does not show significant improvement in overall survival. The impaired efficacy of regorafenib caused by various resistance mechanisms, including epithelial-mesenchymal transitions, inflammation, angiogenesis, hypoxia, oxidative stress, fibrosis and autophagy, still needs to be resolved. In this review, we provide insight on regorafenib microenvironmental, molecular and cellular mechanisms and interactions in HCC treatment. The aim of this review is to help physicians select patients that would obtain the maximal benefits from regorafenib in HCC therapy.

Downregulation of thioredoxin-1-dependent CD95 S-nitrosation by Sorafenib reduces liver cancer

Hepatocellular carcinoma (HCC) represents 80% of the primary hepatic neoplasms. It is the sixth most frequent neoplasm, the fourth cause of cancer-related death, and 7% of registered malignancies. Sorafenib is the first line molecular targeted therapy for patients in advanced stage of HCC. The present study shows that Sorafenib exerts free radical scavenging properties associated with the downregulation of nuclear factor E2-related factor 2 (Nrf2)-regulated thioredoxin 1 (Trx1) expression in liver cancer cells. The experimental downregulation and/or overexpression strategies showed that Trx1 induced activation of nitric oxide synthase (NOS) type 3 (NOS3) and S-nitrosation (SNO) of CD95 receptor leading to an increase of caspase-8 activity and cell proliferation, as well as reduction of caspase-3 activity in liver cancer cells. In addition, Sorafenib transiently increased mRNA expression and activity of S-nitrosoglutathione reductase (GSNOR) in HepG2 cells. Different experimental models of hepatocarcinogenesis based on the subcutaneous implantation of HepG2 cells in nude mice, as well as the induction of HCC by diethylnitrosamine (DEN) confirmed the relevance of Trx1 downregulation during the proapoptotic and antiproliferative properties induced by Sorafenib. In conclusion, the induction of apoptosis and antiproliferative properties by Sorafenib were related to Trx1 downregulation that appeared to play a relevant role on SNO of NOS3 and CD95 in HepG2 cells. The transient increase of GSNOR might also participate in the deactivation of CD95-dependent proliferative signaling in liver cancer cells.

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Sorafenib induces mitochondrial ROS generation, but also acts as nucleophilic scavenger.

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Sorafenib reduces Nrf2-depenent Trx1 expression, and SNO–NOS3 and SNO-CD95 ratios.

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Sorafenib-related antitumoral in vivo activity involves diminution of Trx1 and SNO-CD95.

Protein kinase inhibitor-based cancer therapies: Considering the potential of nitric oxide (NO) to improve cancer treatment

The deregulation of a wide variety of protein kinases is associated with cancer cell initiation and tumor progression. Owing to their indispensable function in signaling pathways driving malignant cell features, protein kinases constitute major therapeutic targets in cancer. Over the past two decades, intense efforts in drug development have been dedicated to this field. The development of protein kinase inhibitors (PKIs) have been a real breakthrough in targeted cancer therapy. Despite obvious successes across patients with different types of cancer, the development of PKI resistance still prevails. Combination therapies are part of a comprehensive approach to address the problem of drug resistance. The therapeutic use of nitric oxide (NO) donors to bypass PKI resistance in cancer has never been tested in clinic yet but several arguments suggest that the combination of PKIs and NO donors may exert a potential anticancer effect. The present review summarized the current state of knowledge on common targets to both PKIs and NO. Herein, we attempt to provide the rationale underlying a potential combination of PKIs and NO donors for future directions and design of new combination therapies in cancer.

Role of BRAF in Hepatocellular Carcinoma: A Rationale for Future Targeted Cancer Therapies

The few therapeutic strategies for advance hepatocellular carcinoma (HCC) on poor knowledge of its biology. For several years, sorafenib, a tyrosine kinase inhibitors (TKI) inhibitor, has been the approved treatment option, to date, for advanced HCC patients. Its activity is the inhibition of the retrovirus-associated DNA sequences protein (RAS)/Rapidly Accelerated Fibrosarcoma protein (RAF)/mitogen-activated and extracellular-signal regulated kinase (MEK)/extracellular-signal regulated kinases (ERK) signaling pathway. However, the efficacy of sorafenib is limited by the development of drug resistance, and the major neuronal isoform of RAF, BRAF and MEK pathways play a critical and central role in HCC escape from TKIs activity. Advanced HCC patients with a BRAF mutation display a multifocal and/or more aggressive behavior with resistance to TKI. Moreover, also long non-coding RNA (lnc-RNA) have been studied in epigenetic studies for BRAF aggressiveness in HCC. So far, lnc-RNA of BRAF could be another mechanism of cancer proliferation and TKI escape in HCC and the inhibition could become a possible strategy treatment for HCC. Moreover, recent preclinical studies and clinical trials evidence that combined treatments, involving alternative pathways, have an important role of therapy for HCC and they could bypass resistance to the following TKIs: MEK, ERKs/ribosomal protein S6 kinase 2 (RSK2), and phosphatidylinositol 3-kinase (PI3K)/mammalian target of rapamycin (mTOR). These initial data must be confirmed in clinical studies, which are currently ongoing. Translational research discoveries could create new strategies of targeted therapy combinations, including BRAF pathway, and they could eventually bring light in new treatment of HCC.

Sorafenib-Induced Apoptosis in Hepatocellular Carcinoma Is Reversed by SIRT1

Sorafenib is a multi-kinase inhibitor and one of the few systemic treatment options for patients with advanced hepatocellular carcinomas (HCCs). Resistance to sorafenib develops frequently and could be mediated by the nicotinamide adenine dinucleotide (NAD)-dependent deacetylase sirtuin (SIRT)1. We aimed to test whether sorafenib efficacy is influenced by cellular NAD levels and NAD-dependent SIRT1 function. We analyzed sorafenib effects on apoptosis induction, NAD salvage, mitochondrial function, and related signaling pathways in HCC cell lines (HepG2, Hep3B, und HUH7) overexpressing SIRT1 or supplemented with the NAD metabolite nicotinamide mononucleotide (NMN) compared to controls. Treatment of HCC cell lines with sorafenib dose-dependently induced apoptosis and a significant decrease in cellular NAD concentrations. The SIRT1 protein was downregulated in HUH7 cells but not in Hep3B cells. After sorafenib treatment, mitochondrial respiration in permeabilized cells was lower, citrate synthase activity was attenuated, and cellular adenosine triphosphate (ATP) levels were decreased. Concomitant to increased phosphorylation of adenosine monophosphate (AMP)-activated protein kinase (AMPK), sorafenib treatment led to decreased activity of the mechanistic target of rapamycin (mTOR), indicative of energy deprivation. Transient overexpression of SIRT1, as well as NAD repletion by NMN, decreased sorafenib-induced apoptosis. We can, therefore, conclude that sorafenib influences the NAD/SIRT1/AMPK axis. Overexpression of SIRT1 could be an underlying mechanism of resistance to sorafenib treatment in HCC.

TARBP2-mediated destabilization of Nanog overcomes sorafenib resistance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a lethal human malignancy and a leading cause of cancer‐related death worldwide. Patients with HCC are often diagnosed at an advanced stage, and the prognosis is usually poor. The multikinase inhibitor sorafenib is the first‐line treatment for patients with advanced HCC. However, cases of primary or acquired resistance to sorafenib have gradually increased, leading to a predicament in HCC therapy. Thus, it is critical to investigate the mechanism underlying sorafenib resistance. Transactivation response element RNA‐binding protein 2 (TARBP2) is a multifaceted miRNA biogenesis factor that regulates cancer stem cell (CSC) properties. The tumorigenicity and drug resistance of cancer cells are often enhanced due to the acquisition of CSC features. However, the role of TARBP2 in sorafenib resistance in HCC remains unknown. Our results demonstrate that TARBP2 is significantly downregulated in sorafenib‐resistant HCC cells. The TARBP2 protein was destabilized through autophagic–lysosomal proteolysis, thereby stabilizing the expression of the CSC marker protein Nanog, which facilitates sorafenib resistance in HCC cells. In summary, here we reveal a novel miRNA‐independent role of TARBP2 in regulating sorafenib resistance in HCC cells.

PDCD2 sensitizes HepG2 cells to sorafenib by suppressing epithelial‑mesenchymal transition

Epithelial-mesenchymal transition (EMT) has an established role in the acquisition of therapeutic resistance. Programmed cell death domain 2 (PDCD2) is involved in the progression of multiple types of cancer. However, its mechanism underlying chemoresistance in liver cancer has not been elucidated. In the present study, it was demonstrated that the sorafenib-resistant HepG2 cell line exhibited EMT and multidrug resistance (MDR) phenotypes, and reduced expression of PDCD2, by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot analysis and Cell Counting Kit-8. Annexin V/fluorescein isothiocyanate and cell migration assays further demonstrated that PDCD2 effectively promoted sorafenib-induced cell apoptosis and reduced cell metastasis. Mechanistically, PDCD2 inhibited the expression of Vimentin and increased the expression of E-cadherin in a Snail-dependent manner by RT-qPCR and western blot analysis. In conclusion, the present study elucidated for the first time, to the best of our knowledge, that PDCD2 sensitizes sorafenib-resistant HepG2 cells to sorafenib by the downregulation of EMT. PDCD2 may serve as a potential therapeutic target in the treatment of sorafenib-resistant liver cancer.

Blocking CDK1/PDK1/β-Catenin signaling by CDK1 inhibitor RO3306 increased the efficacy of sorafenib treatment by targeting cancer stem cells in a preclinical model of hepatocellular carcinoma

Rationale: Hepatocellular carcinoma (HCC) is an aggressive malignant solid tumor wherein CDK1/PDK1/β-Catenin is activated, suggesting that inhibition of this pathway may have therapeutic potential. Methods: CDK1 overexpression and clinicopathological parameters were analyzed. HCC patient-derived xenograft (PDX) tumor models were treated with RO3306 (4 mg/kg) or sorafenib (30 mg/kg), alone or in combination. The relevant signaling of CDK1/PDK1/β-Catenin was measured by western blot. Silencing of CDK1 with shRNA and corresponding inhibitors was performed for mechanism and functional studies. Results: We found that CDK1 was frequently augmented in up to 46% (18/39) of HCC tissues, which was significantly associated with poor overall survival (p=0.008). CDK1 inhibitor RO3306 in combination with sorafenib treatment significantly decreased tumor growth in PDX tumor models. Furthermore, the combinatorial treatment could overcome sorafenib resistance in the HCC case #10 PDX model. Western blot results demonstrated the combined administration resulted in synergistic down-regulation of CDK1, PDK1 and β-Catenin as well as concurrent decreases of pluripotency proteins Oct4, Sox2 and Nanog. Decreased CDK1/PDK1/β-Catenin was associated with suppression of epithelial mesenchymal transition (EMT). In addition, a low dose of RO3306 and sorafenib combination could inhibit 97H CSC growth via decreasing the S phase and promoting cells to enter into a Sub-G1 phase. Mechanistic and functional studies silencing CDK1 with shRNA and RO3306 combined with sorafenib abolished oncogenic function via downregulating CDK1, with downstream PDK1 and β-Catenin inactivation. Conclusion: Anti-CDK1 treatment can boost sorafenib antitumor responses in PDX tumor models, providing a rational combined treatment to increase sorafenib efficacy in the clinic.

Enhancing anti-tumor efficiency in hepatocellular carcinoma through the autophagy inhibition by miR-375/sorafenib in lipid-coated calcium carbonate nanoparticles

Sorafenib is a first-line drug for hepatocellular carcinoma (HCC). Autophagy has been shown to facilitate sorafenib resistance. miR-375 has been shown to be an inhibitor of autophagy. In this study, miR-375 and sorafenib were co-loaded into calcium carbonate nanoparticles with lipid coating (miR-375/Sf-LCC NPs). The nanoparticles had high loading efficiency and were ∼50 nm in diameter. Besides, the NPs could increase the stability and residence time of both drugs. Moreover, we demonstrated that autophagy was activated in HCC cells by sorafenib but not by miR-375/Sf-LCC NPs. In vitro, miR-375/Sf-LCC NPs exhibited pH-dependent drug release and potent cytotoxicity. In vivo, miR-375/Sf-LCC NPs increased miR-375 and sorafenib uptake in tumor (2 folds compared with Lipofectamine 2000-miR-375 and 2-5 folds compared with free sorafenib). Furthermore, miR-375/Sf-LCC NPs showed greatly enhanced therapeutic efficacy in an HCC xenograft model. These findings suggest that miR-375/Sf-LCC NPs may be a promising agent for the HCC therapy.

STATEMENT OF SIGNIFICANCE

Hepatocellular carcinoma (HCC) is the most common primary liver tumor and the third leading cause of cancer mortality globally. In this manuscript, miR-375 and sorafenib were co-loaded into calcium carbonate nanoparticles with lipid coating (miR-375/Sf-LCC NPs) to treat HCC. We demonstrated that miR-375/Sf-LCC NPs can deliver sorafenib and miR-375 into HCC cells and tumor tissues, increase drug retention time in tumor, significantly inhibit autophagy and produce enhanced anti-tumor effect.

A new inhibitor of glucose-6-phosphate dehydrogenase blocks pentose phosphate pathway and suppresses malignant proliferation and metastasis in vivo

Pentose phosphate pathway (PPP) is a major glucose metabolism pathway, which has a fundamental role in cancer growth and metastasis. Even though PPP blockade has been pointed out as a very promising strategy against cancer, effective anti-PPP agents are not still available in the clinical setting. Here we demonstrate that the natural molecule polydatin inhibits glucose-6-phosphate dehydrogenase (G6PD), the key enzyme of PPP. Polydatin blocks G6PD causing accumulation of reactive oxygen species and strong increase of endoplasmic reticulum stress. These effects are followed by cell cycle block in S phase, an about 50% of apoptosis, and 60% inhibition of invasion in vitro. Accordingly, in an orthotopic metastatic model of tongue cancer, 100 mg/kg polydatin induced an about 30% tumor size reduction with an about 80% inhibition of lymph node metastases and 50% reduction of lymph node size (p < 0.005). Polydatin is not toxic in animals up to a dose of 200 mg/kg and a phase II clinical trial shows that it is also well tolerated in humans (40 mg twice a day for 90 days). Thus, polydatin may be used as a reliable tool to limit human cancer growth and metastatic spread.

Glutathione-mediated antioxidant response and aerobic metabolism: two crucial factors involved in determining the multi-drug resistance of high-risk neuroblastoma

Neuroblastoma, a paediatric malignant tumor, is initially sensitive to etoposide, a drug to which many patients develop chemoresistance. In order to investigate the molecular mechanisms responsible for etoposide chemoresistance, HTLA-230, a human MYCN-amplified neuroblastoma cell line, was chronically treated with etoposide at a concentration that in vitro mimics the clinically-used dose. The selected cells (HTLA-Chr) acquire multi-drug resistance (MDR), becoming less sensitive than parental cells to high doses of etoposide or doxorubicin. MDR is due to several mechanisms that together contribute to maintaining non-toxic levels of H₂O₂. In fact, HTLA-Chr cells, while having an efficient aerobic metabolism, are also characterized by an up-regulation of catalase activity and higher levels of reduced glutathione (GSH), a thiol antioxidant compound. The combination of such mechanisms contributes to prevent membrane lipoperoxidation and cell death. Treatment of HTLA-Chr cells with L-Buthionine-sulfoximine, an inhibitor of GSH biosynthesis, markedly reduces their tumorigenic potential that is instead enhanced by the exposure to N-Acetylcysteine, able to promote GSH synthesis.

Collectively, these results demonstrate that GSH and GSH-related responses play a crucial role in the acquisition of MDR and suggest that GSH level monitoring is an efficient strategy to early identify the onset of drug resistance and to control the patient's response to therapy.

Metformin and insulin impact on clinical outcome in patients with advanced hepatocellular carcinoma receiving sorafenib: Validation study and biological rationale

PURPOSE

In 2015, we published a study on a small series of patients with hepatocellular carcinoma (HCC) treated chronically with metformin for type II diabetes mellitus (DM2) who showed a poorer response to sorafenib. The aim of the present study was to validate the prognostic significance of metformin in HCC patients treated with sorafenib, providing a biological rationale for the mechanism of resistance to sorafenib in patients on chronic metformin therapy, and to clarify the role of sirtuin-3 (SIRT-3), a protein involved in metabolic diseases and acknowledged as a tumour suppressor in HCC, in this resistance.

PATIENTS AND METHODS

We analysed 279 patients consecutively treated with sorafenib for the clinical analysis. Of the 86 (30%) patients with DM2, 52 (19%) were on chronic treatment with metformin and 34 (12%) with insulin. We included 43 patients with HCC for the biological study: 19 (44.1%) were diabetic and 14 (73.7%) of these received metformin for DM2. SIRT-3 expression was investigated by immunohistochemistry (IHC) in formalin-fixed and paraffin-embedded (FFPE) samples.

RESULTS

In HCC patients undergoing chronic treatment with metformin, the use of sorafenib was associated with poor progression-free survival (PFS) and overall survival (OS) (1.9 and 6.6 months, respectively) compared to 3.7 months and 10.8 months, respectively, for patients without DM2 and 8.4 months and 16.6 months, respectively, for patients on insulin (P < .0001). We also observed that SIRT-3 protein expression was significantly higher in patients treated with metformin than in those not taking this medication (65% versus 25%, respectively) (P = .013).

CONCLUSIONS

Our findings could be attributed to increased tumour aggressiveness and resistance to sorafenib caused by chronic treatment with metformin.

Molecular mechanisms governing microRNA-125a expression in human hepatocellular carcinoma cells

MicroRNA-125a-5p (miR-125a) is a vertebrate homolog of lin-4, the first discovered microRNA, and plays a fundamental role in embryo development by downregulating Lin-28 protein. MiR-125a is also expressed in differentiated cells where it generally acts as an antiproliferative factor by targeting membrane receptors or intracellular transductors of mitogenic signals. MiR-125a expression is downregulated in several tumors, including hepatocellular carcinoma (HCC) where it targets sirtuin-7, matrix metalloproteinase-11, VEGF-A, Zbtb7a, and c-Raf. In this study, we have isolated the transcription promoter of human miR-125a and characterized its activity in HCC cells. It is a TATA-less Pol II promoter provided with an initiator element and a downstream promoter element, located 3939 bp upstream the genomic sequence of the miRNA. The activity of the promoter is increased by the transcription factor NF-kB, a master regulator of inflammatory response, and miR-125a itself was found to strengthen this activation through inhibition of TNFAIP3, a negative regulator of NF-kB. This finding contributes to explain the increased levels of miR-125a observed in the liver of patients with chronic hepatitis B.

Development of hepatocellular cancer induced by long term low fat-high carbohydrate diet in a NAFLD/NASH mouse model

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease. It can progress to nonalcoholic steatohepatitis (NASH) and, in a percentage of cases, to hepatocarcinogenesis. The strong incidence in western countries of obesity and metabolic syndrome, whose NAFLD is the hepatic expression, is thought to be correlated to consumption of diets characterized by processed food and sweet beverages. Previous studies described high-fat diet-induced liver tumors. Conversely, the involvement of low-fat/high-carbohydrate diet in the progression of liver disease or cancer initiation has not been described yet. Here we show for the first time hepatic cancer formation in low-fat/high-carbohydrate diet fed NAFLD/NASH mouse model. Animals were long term high-fat, low-fat/high-carbohydrate or standard diet fed. We observed progressive liver damage in low-fat/high-carbohydrate and high-fat animals after 12 and, more, 18 months. Tumors were detected in 20% and 50% of high-fat diet fed mice after 12 and 18 months and, interestingly, in 30% of low-fat/high-carbohydrate fed animals after 18 months. No tumors were detected in standard diet fed mice. Global increase of hepatic interleukin-1β, interleukin-6, tumor necrosis factor-α and hepatocyte growth factor was detected in low-fat/high-carbohydrate and high-fat with respect to standard diet fed mice as well as in tumor with respect to non-tumor bearing mice. A panel of 15 microRNAs was analyzed: some of them revealed differential expression in low-fat/high-carbohydrate with respect to high-fat diet fed groups and in tumors. Data here shown provide the first evidence of the involvement of low-fat/high-carbohydrate diet in hepatic damage leading to tumorigenesis.

Oxidative Stress Promotes Doxorubicin-Induced Pgp and BCRP Expression in Colon Cancer Cells Under Hypoxic Conditions

P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP) are ATP binding cassette (ABC) transporters that are overexpressed in different drug-resistant cancer cell lines. In this study, we investigated whether doxorubicin promotes Pgp and/or BCRP expression to induce drug resistance in colon cancer cells under hypoxic conditions. We analyzed HIF-1α activity via ELISA, Pgp, and BCRP expression by qRT-PCR and the relationship between doxorubicin uptake and ABC transporter expression via confocal microscopy in HT-29WT and HT-29 doxorubicin-resistant colon cancer cells (HT-29DxR). These cells were treated with doxorubicin and/or CoCl₂ (chemical hypoxia), and reactive oxygen species inductors. We found that the combination of chemically induced hypoxia and doxorubicin promoted Pgp mRNA expression within 24 h in HT-29WT and HT-29DxR cells. Both doxorubicin and CoCl₂ alone or in combination induced Pgp and BCRP expression, as demonstrated via confocal microscopy in each of the above two cell lines. Thus, we surmised that Pgp and BCRP expression may result from synergistic effects exerted by the combination of doxorubicin-induced ROS production and HIF-1α activity under hypoxic conditions. However, HIF-1α activity disruption via the administration of E3330, an APE-1 inhibitor, downregulated Pgp expression and increased doxorubicin delivery to HT-29 cells, where it served as a substrate for Pgp, indicating the existence of an indirect relationship between Pgp expression and doxorubicin accumulation. Thus, we concluded that Pgp and BCRP expression can be regulated via cross-talk between doxorubicin and hypoxia, promoting drug resistance in HT-29 WT, and HT-29DxR cells and that this process may be ROS dependent. J. Cell. Biochem. 118: 1868-1878, 2017. © 2017 Wiley Periodicals, Inc.

Increased expression of urotensin II is associated with poor prognosis in hepatocellular carcinoma

Urotensin II (UII) and the urotensin II receptor (UT) exhibit mitogenic effects on tumor growth. Our previous study demonstrated that the UII/UT system is upregulated in hepatocellular carcinoma (HCC) and may enhance the proliferation of human hepatoma cells. However, the clinical significance of UII/UT expression in HCC remains unclear. The present study assessed UII messenger RNA (mRNA) expression in 129 surgical specimens obtained from HCC patients using reverse transcription quantitative-polymerase chain reaction. The association between UII mRNA expression and clinicopathological parameters and overall survival rates was also investigated. The results revealed that UII and UT mRNA expression was significantly increased in HCC tissue compared with adjacent non-cancerous liver tissue (P<0.001). Furthermore, a significant correlation was identified between UII expression and histological differentiation (P<0.01), tumor size (P<0.01) and tumor stage (P=0.026). Kaplan-Meier survival analysis indicated that overall survival time was significantly shorter in patients with high UII expression, compared with those with low UII expression (P<0.001). Multivariate analyses indicated that UII expression was an independent predictor of overall survival (odds ratio, 1.12; P<0.001). In addition, UII mRNA was correlated with vascular endothelial growth factor mRNA expression. Therefore, UII expression is an independent biomarker for the prognosis of patients with HCC and thus, the UII/UT system may present a novel therapeutic target for the treatment of HCC.

A novel prognostic biomarker SPC24 up-regulated in hepatocellular carcinoma

SPC24 is an important component of the nuclear division cycle 80 (Ndc80) kinetochore complex, which plays an essential role in the coupling of kinetochore to spindle microtubules (MTs) and the accurate segregation of chromosomes during mitosis. However, the functional role of SPC24 in hepatocellular carcinoma (HCC) remains unknown. Here, we detected the expression of SPC24 in HCC and analyzed its association with clinicopathologic features and prognosis of HCC patients. The expression of SPC24 mRNA was investigated in 212 cases of paired HCC and adjacent liver tissues by quantitative real-time PCR (qRT-PCR) and in the tissues of 20 HCC patients by semi-quantitative RT-PCR. Additionally, the expression of SPC24 protein was detected in 69 cases of HCC by immunohistochemistry (IHC) or in 2 cases of HCC tissues by Western-blotting. Furthermore, small interfering RNA (siRNA)-mediated silencing of SPC24 was employed in SMMC7721 and HepG2 human HCC cells to investigate cell proliferation, invasion and apoptosis. Survival curves were plotted using the Kaplan-Meier method, and differences in survival probability were obtained using the log-rank test. Independent predictors associated with disease-free survival (DFS) and overall survival (OS) were analyzed using the Cox proportional-hazards regression model. In this study, we showed that SPC24 was noticeably increased in HCC tissues compared to normal adjacent noncancerous tissues, at both mRNA and protein levels. High expression of SPC24 was significantly correlated with alpha-fetoprotein (AFP) (p = 0.044), median size (p = 0.030), tumor number (p = 0.019), and Barcelona-Clinic Liver Cancer (BCLC) stage (p = 0.015). Kaplan-Meier analysis showed that the DFS and OS of high SPC24 expression group was significantly shorter than that of low SPC24 expression group (p < 0.001; p = 0.001; respectively). The prognostic impact of SPC24 was further confirmed by stratified survival analysis. Importantly, multivariate analysis identified SPC24 upregualtion (p = 0.001), PVTT (p = 0.007), size of tumor > 5 cm (p < 0.001) as independent risk factors of DFS after resection, and SPC24 upregualtion (p < 0.001), PVTT (p = 0.029), size of tumor > 5 cm (p = 0.002), recurrence (p < 0.001) as independent prognostic factors for the OS of HCC patients. Additionally, siRNA-mediated silencing of SPC24 dramatically suppressed cell growth, adhesion, invasion and increased apoptosis in HCC cells. In conclusion, these results showed for the first time that SPC24 expression was significantly up-regulated in HCC, which may act as a novel prognostic biomarker for patients suffering from this deadly disease. Additionally, silence of SPC24 inhibiting HCC cell growth indicated that SPC24 may be a promising molecular target for HCC therapy.

Endothelial progenitor cell number and ERK phosphorylation serve as predictive and prognostic biomarkers in advanced hepatocellular carcinoma patients treated with sorafenib

Sorafenib is an oral anti-angiogenic multi-kinase inhibitor used for systemic therapy in patients with advanced hepatocellular carcinoma (HCC) who are not suitable candidates for surgery or liver transplantation. An earlier study conducted with HCC tumor tissue suggested that ERK phosphorylation (pERK), a downstream target of sorafenib, may serve as a potential biomarker for therapeutic efficacy of sorafenib. However, no study thus far has utilized a minimal invasive procedure to predict HCC patient responsiveness to sorafenib. We evaluated the biomarker utility of circulating endothelial progenitor cells (EPCs) frequency and intracellular pERK levels in EPCs in peripheral blood obtained pre- and post-sorafenib therapy or after transarterial chemoembolistaion (TACE). A statistically significant reduction in the level of ERK phosphorylation and in the absolute number of EPCs was detected following in vivo sorafenib treatment (p < 0 .01 for both). In contrast, the decrease in the level of ERK phosphorylation and EPC number was either marginally significant or insignificant in patients treated with TACE (p = 0.05 and 0.06, respectively). In vitro sorafenib treatment of pre- and post-samples from the same patient cohort inhibited ERK phosphorylation levels in EPCs and decreased the number of EPCs at all doses tested (p = 0.01). Our findings support that the evaluation of both the circulating EPC frequency and the level of ERK phosphorylation in EPCs may serve as potential non-invasive biomarkers of sorafenib efficacy, both as predictor of treatment outcome and efficacy during drug treatment.

Self-assembling nanoparticles encapsulating zoledronic acid revert multidrug resistance in cancer cells

The overexpression of ATP binding cassette (ABC) transporters makes tumor cells simultaneously resistant to several cytotoxic drugs. Impairing the energy metabolism of multidrug resistant (MDR) cells is a promising chemosensitizing strategy, but many metabolic modifiers are too toxic in vivo. We previously observed that the aminobisphosphonate zoledronic acid inhibits the activity of hypoxia inducible factor-1α (HIF-1α), a master regulator of cancer cell metabolism. Free zoledronic acid, however, reaches low intratumor concentration. We synthesized nanoparticle formulations of the aminobisphosphonate that allow a higher intratumor delivery of the drug. We investigated whether they are effective metabolic modifiers and chemosensitizing agents against human MDR cancer cells in vitro and in vivo.

At not toxic dosage, nanoparticles carrying zoledronic acid chemosensitized MDR cells to a broad spectrum of cytotoxic drugs, independently of the type of ABC transporters expressed. The nanoparticles inhibited the isoprenoid synthesis and the Ras/ERK1/2-driven activation of HIF-1α, decreased the transcription and activity of glycolytic enzymes, the glucose flux through the glycolysis and tricarboxylic acid cycle, the electron flux through the mitochondrial respiratory chain, the synthesis of ATP. So doing, they lowered the ATP-dependent activity of ABC transporters, increasing the chemotherapy efficacy in vitro and in vivo. These effects were more pronounced in MDR cells than in chemosensitive ones and were due to the inhibition of farnesyl pyrophosphate synthase (FPPS), as demonstrated in FPPS-silenced tumors.

Our work proposes nanoparticle formulations of zoledronic acid as the first not toxic metabolic modifiers, effective against MDR tumors.

PD-1+ and Foxp3+ T cell reduction correlates with survival of HCC patients after sorafenib therapy

BACKGROUND

Sorafenib is an oral antiangiogenic agent administered in advanced-stage hepatocellular carcinoma (HCC). Based on preclinical and human studies, we hypothesized that, in addition to its antiangiogenic properties, sorafenib may beneficially reduce the extent of the immunosuppressive network in HCC patients. To test this hypothesis, we examined whether alterations in the immunosuppressive burden of advanced-stage HCC patients correlated with clinical outcome.

METHODS

In before and after sorafenib treatment, blood samples collected from 19 patients with advanced HCC, the frequency of PD-1⁺ T cells, Tregs, and myeloid derived suppressor cells (MDSC) were quantified by multiparameter FACS. Cytokine levels in plasma were determined by ELISA.

RESULTS

Overall survival (OS) was significantly impacted by the reduction in the absolute number of both CD4⁺PD-1⁺ T cells and CD8⁺PD-1⁺ T cells following sorafenib treatment. Significant decreases in the frequency and absolute number of Foxp3⁺ Tregs were also observed, and a statistically significant improvement in OS was noted in patients exhibiting a greater decrease in the number of Foxp3⁺ Tregs. The ratio of CD4⁺CD127⁺PD-1^- T effector cells to CD4⁺Foxp3⁺PD-1⁺ Tregs was significantly increased following treatment with sorafenib. Increased frequency of CD4⁺CD127⁺ T effector cells in the posttreatment samples significantly correlated with OS.

CONCLUSION

This study is the first to our knowledge to demonstrate the potent immunomodulatory effects of sorafenib therapy on PD-1⁺ T cells and Tregs and the ensuing correlation with survival. These phenotypes could serve as predictive biomarkers to identify HCC patients who are likely to benefit from sorafenib treatment.

TRIAL REGISTRATION

Registration is not required for observational studies.

FUNDING

This study was supported by NCI Core Grant to RPCI (NIH P30 CA016056) and discretionary funds to Y. Thanavala.

The role and mechanism of autophagy in sorafenib targeted cancer therapy

Targeting kinase inhibitors (TKIs) are effective tools for treating advanced cancer. However, acquired resistance represents a roadblock in the use of TKIs, such as sorafenib, for cancer therapy. Understanding the acquisition of resistance to sorafenib will help doctors to cope with acquired resistance to TKIs in general and to develop personalized medicine strategies for cancer patients. Autophagy is a biological process that occurs in normal organisms. However, it is also a component of multiple disease processes, including cancer development and progression. However, the roles of autophagy in cancer and in response to cancer therapy are controversial. In this review, we summarize the progress in autophagy and sorafenib resistance research, which is representative of acquired resistance to targeted cancer therapy.

Pathophysiological mechanisms and therapeutic potentials of macrophages in non-alcoholic steatohepatitis

INTRODUCTION

Non-alcoholic steatohepatitis (NASH), a hepatic manifestation of metabolic syndrome, is a major cause of morbidity and healthcare burden worldwide. While the molecular pathogenesis of NASH remains unclear and therapeutic options are limited, inflammation is recognized as an essential factor for NASH development. Factors that link NASH to inflammation are macrophages and their secreted cytokines.

AREAS COVERED

This review summarizes the current knowledge of macrophage-mediated molecular pathways in NASH to shed insights on potential pharmacotherapeutic applications.

EXPERT OPINION

Macrophages are not only known for their role of phagocytosis in innate immunity, but also for both extrinsic and intrinsic regulation of inflammatory functions of many cytokines. Recent advances have revealed the effects of macrophage recruitment and polarization on the development of NASH. We and others have shown that the proliferation of hepatic macrophages and the subsequent production of pro-inflammatory cytokines initiates inflammatory cascades, orchestrates activities of transcription factors involved in lipid metabolism/translocation, and modulates programmed cell death. Together, these findings support the pathophysiological role of macrophages in the pathogenesis of NASH. Thus, evaluating potential therapeutic targets against the infiltration and/or polarization of specific macrophage subtypes is of clinical interest for alleviation of early-stage NASH, with the goal of halting disease progression.

Improved antitumor activity of epirubicin-loaded CXCR4-targeted polymeric nanoparticles in liver cancers

A liver-targeted drug delivery system (CX-EPNP) composed of PLGA/TPGS was prepared and characterized. The surface of nanoparticle was conjugated with LFC131 peptide to increase the specific interaction of carrier with CXCR4 overexpressing liver cancers to enhance the Epirubicin (EPI) delivery to tumors. The particles were nanosized with size than 150 nm and portrayed a sustained release kinetics suggesting its suitability for cancer targeting. The in vitro cell uptake results showed that the introduction of LFC131 to the nanoparticles could increase significantly the affinity to human hepatic carcinoma cells (HepG2) with approximately a 3-fold improvement in cellular uptake than non-targeted one. A specific receptor-mediated uptake was observed by confocal laser scanning microscopy. In addition, CX-EPNP showed remarkable cytotoxicity towards HepG2 cells, and could effectively inhibit tumor growth. The more significant EPI accumulation from CX-EPNP in the cancer cells gave rise to the enhanced EPI cytotoxicity and cell apoptosis. The CX-EPNP distributed mostly in the xenograft tumor after intravenous administration to mice and adequately remained in the blood for at least 24h. It seemed that CX-EPNP upon intravenous injection avoided rapid recognition by Kupffer cells and adequately remained in the blood. These findings suggest that CX-EPNP could effectively inhibit the growth of liver tumors in situ and could potentially reduce the systemic side effects. However, extensive investigation is still needed to assess the possible applications of the CX-EPNP in humans.

Predictive biomarkers of sorafenib efficacy in advanced hepatocellular carcinoma: Are we getting there?

Sorafenib is the current standard treatment for advanced hepatocellular carcinoma (HCC), but its efficacy is modest with low response rates and short response duration. Predictive biomarkers for sorafenib efficacy are necessary. However, efforts to determine biomarkers for sorafenib have led only to potential candidates rather than clinically useful predictors. Studies based on patient cohorts identified the potential of blood levels of angiopoietin-2, hepatocyte growth factor, insulin-like growth factor-1, and transforming growth factor-β1 for predicting sorafenib efficacy. Alpha-fetoprotein response, dynamic contrast-enhanced magnetic resonance imaging, and treatment-related side effects may serve as early surrogate markers. Novel approaches based on super-responders or experimental mouse models may provide new directions in biomarker research. These studies identified tumor amplification of FGF3/FGF4 or VEGFA and tumor expression of phospho-Mapk14 and phospho-Atf2 as possible predictive markers that await validation. A group effort that considers various prognostic factors and proper collection of tumor tissues before treatment is imperative for the success of future biomarker research in advanced HCC.

Folate-decorated anticancer drug and magnetic nanoparticles encapsulated polymeric carrier for liver cancer therapeutics

Nanoparticulate system with theranostic applications has attracted significant attention in cancer therapeutics. In the present study, we have developed a novel composite PLGA NP co-encapsulated with anticancer drug (sorafenib) and magnetic NP (SPION). We have successfully developed nanosized folate-conjugated PEGylated PLGA nanoparticles (SRF/FA-PEG-PLGA NP) with both anticancer and magnetic resonance property. We have showed that FA-conjugated NP exhibits sustained drug release and enhanced cellular uptake in BEL7402 cancer cells. The targeted NP effectively suppressed the tumor cell proliferation and has improved the anticancer efficacy than that of free drug or non-targeted one. Additionally, enhanced MRI properties demonstrate this formulation has good imaging agent characteristics. Finally, SRF/FA-PEG-PLGA NP effectively inhibited the colony forming ability indicating its superior anticancer effect. Together, these multifunctional nanoparticles would be most ideal to improve the therapeutic response in cancer and holds great potential to be a part of future nanomedicine. Our unique approach could be extended for multiple biomedical applications.

Levofolene modulates apoptosis induced by 5-fluorouracil through autophagy inhibition: clinical and occupational implications

5-Fluorouracil (5-FU), often used in combination with levofolene (LF), can induce, as an important side effect, the hand-foot syndrome (HFS) due to toxicity on keratinocytes. This can also damage workers involved in its handling. In the present study, we investigated the mechanisms of the toxicity induced by 5-FU alone or together with LF on human keratinocytes in culture. We found that the two drugs, as expected, had potentiating activity on keratinocyte growth inhibition and that this effect was mediated by induction of apoptosis. In our experimental model, an increased autophagic vacuole accumulation was observed in keratinocytes treated with 5-FU as a significant increase of the monodansylcadaverine (MDC) labeling (marker of late autophagy vacuoles) was recorded. However, the synergism of 5-FU with LF on apoptotic occurrence was not paralleled by a similar increase in autophagic vacuoles at 72 h suggesting an antagonistic effect of LF on autophagy elicited by 5-FU. Differential effects on reactive oxygen species (ROS) elevation in cells treated with 5-FU alone or the combination between 5-FU and LF were also observed. 5-FU induced a time-dependent increase of both O²⁻ and lipid peroxidation while the combination of 5-FU and LF caused a stronger intracellular O²⁻ increase only at 24 h while at 48 and 72 h its effect was lower when compared with that one of 5-FU alone. On the other hand, the addition of LF to 5-FU caused a stronger increase of lipid peroxidation at 48 and 72 h, but its effects were significantly lower at 24 h. These results suggest for the first time that LF potentiates the cytotoxicity of 5-FU on keratinocytes likely through the antagonism on autophagy escape pathway and consequent apoptosis potentiation.

Enhanced therapeutic efficacy and cytotoxicity of doxorubicin-loaded vitamin E – Pluronic micelles against liver cancer

In this study, a new polymeric micelle delivery system was developed to increase the therapeutic efficacy of doxorubicin (DOX) and to reduce its associated side effects.

Curcumin ameliorate DENA-induced HCC via modulating TGF-β, AKT, and caspase-3 expression in experimental rat model

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. In laboratory animal models, diethylnitrosamine (DENA) is a well-known agent that has a potent hepatocarcinogenic effect that is used to induce HCC. As curcumin has a potent anti-inflammatory effect with strong therapeutic potential against a variety of cancers, our present study aims to investigate its curative effects and the possible mechanisms of action against DENA-induced HCC in male rats. Investigation of biochemical and molecular parameters of HCC animal model liver showed an overexpression of TGF-β and Akt proteins accompanied with a significant reduction of the proapoptotic marker caspase-3. DENA-induced hepatic cellular injury resulted also in a significant increase in liver function marker enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lipid peroxides in this group. Curcumin treatment partially reversed DENA-induced damage as it reduced the overexpression of the angiogenic and anti-apoptotic factors TGF-β and Akt and improved caspase-3 expression. Also, it could partially normalize the serum values of liver marker enzymes and lipid peroxidation and improve liver architecture. Curcumin shows a unique chemotherapeutic effect in reversing DENA-induced HCC in rat model. This effect is possibly mediated through its proapoptotic, antioxidant, anti-angiogenic, as well as antimitotic effects. It interferes and modulates cell signaling pathways and hence turns death signals and apoptosis on within tumor cells.

Distinct subpopulations of head and neck cancer cells with different levels of intracellular reactive oxygen species exhibit diverse stemness, proliferation, and chemosensitivity

Head and neck squamous cell carcinoma (HNSCC) is driven by cancer-initiating cells (CIC), but their maintenance mechanisms are obscure. For hematopoietic stem cells, low levels of intracellular reactive oxygen species (ROS(Low)) is known to help sustain stemness properties. In this report, we evaluated the hypothesis that ROS(Low) character conferred CIC properties in HNSCC. Sphere cultures define CIC in HNSCC cell populations (HN-CIC). We found that ROS(Low) cells in HN-CIC defined in this manner were more numerous than in parental HNSCC cells. Further, ROS(Low) cells frequently coexpressed CIC surface markers such as memGrp78 and Glut3. Exploiting flow cytometry to sort cells on the basis of their ROS level, we found that isolated ROS(Low) cells displayed relatively more CIC properties, including quiescence, chemoresistance, in vitro malignant properties, and tumorigenicity. Pharmacological depletion of ROS modulators in cisplatin-treated HN-CIC reduced CIC properties, enhancing cell differentiation and enhancing cisplatin-induced cell death. Overall, our work defined cell subpopulations in HNSCC on the basis of differential intracellular ROS levels, which associated with stemness and chemoresistance properties. On the basis of our findings, we suggest that strategies to promote intracellular ROS levels may heighten the efficacy of conventional chemotherapy used for HNSCC treatment.

The GH-IGF-SST system in hepatocellular carcinoma: biological and molecular pathogenetic mechanisms and therapeutic targets

Hepatocellular carcinoma (HCC) is the sixth most common malignancy worldwide. Different signalling pathways have been identified to be implicated in the pathogenesis of HCC; among these, GH, IGF and somatostatin (SST) pathways have emerged as some of the major pathways implicated in the development of HCC. Physiologically, GH-IGF-SST system plays a crucial role in liver growth and development since GH induces IGF1 and IGF2 secretion and the expression of their receptors, involved in hepatocytes cell proliferation, differentiation and metabolism. On the other hand, somatostatin receptors (SSTRs) are exclusively present on the biliary tract. Importantly, the GH-IGF-SST system components have been indicated as regulators of hepatocarcinogenesis. Reduction of GH binding affinity to GH receptor, decreased serum IGF1 and increased serum IGF2 production, overexpression of IGF1 receptor, loss of function of IGF2 receptor and appearance of SSTRs are frequently observed in human HCC. In particular, recently, many studies have evaluated the correlation between increased levels of IGF1 receptors and liver diseases and the oncogenic role of IGF2 and its involvement in angiogenesis, migration and, consequently, in tumour progression. SST directly or indirectly influences tumour growth and development through the inhibition of cell proliferation and secretion and induction of apoptosis, even though SST role in hepatocarcinogenesis is still opened to argument. This review addresses the present evidences suggesting a role of the GH-IGF-SST system in the development and progression of HCC, and describes the therapeutic perspectives, based on the targeting of GH-IGF-SST system, which have been hypothesised and experimented in HCC.

Short-term diet and moderate exercise in young overweight men modulate cardiocyte and hepatocarcinoma survival by oxidative stress

The present study was designed to evaluate the effects of diet lifestyle on extending lifespan and reducing liver cancer risk. Young overweight men (n = 20), without metabolic syndrome, were placed in a 3-week residential program on a low-fat diet and moderate aerobic exercise. In each subject, pre- and postintervention fasting blood were collected for evaluating levels of serum lipids, and oxidative stress markers. Using subject sera and cardiomyocyte (H9C2) culture systems, we measured heat shock protein 27 and 90 expression, lipid accumulation, and oxidative stress marker levels. After 3-weeks of diet, significant reductions (P < 0.05) in body mass index, serum lipids and lipid ratios, and oxidative markers were recorded. In vitro, we observed that the addition of postintervention sera increased H9C2 cell number and reduced HSP27 and 90 expression, mitochondrial superoxide anion, and lipid accumulation with a parallel increase in nitric oxide (NO) production (all P < 0.01). At the same time, postintervention sera decreased human liver hepatocellular carcinoma cell line (HepG-2) proliferation, lipid accumulation, oxidative stress, and extracellular-signal-regulated kinases (ERK1/2) activity. Lifestyle modification in young overweight men, without metabolic syndrome, could ameliorate cardiocyte survival and reduce hepatocellular carcinoma cell proliferation.

Notch3 inhibition enhances sorafenib cytotoxic efficacy by promoting GSK3b phosphorylation and p21 down-regulation in hepatocellular carcinoma

Sorafenib (Nexavar), a multiple kinase inhibitor, is the only clinically approved drug for patients with advanced HCC. However, its therapeutic success is limited by the emergence of drug resistance. Here we found that p21 and pGSK3β^Ser9 are major players in the resistance to sorafenib. We recently reported that aberrant Notch3 expression in HCC contributes to doxorubicin resistance in vitro and, therefore, we focused on the mechanisms that associate Notch3 to acquired drug resistance. In this study we first found that Notch3 inhibition significantly increased the apoptosis inducing effect of sorafenib in HCC cells via specific down-regulation of p21 and up-regulation of pGSK3β^Ser9. Using a mouse xenograft model we further found that Notch3 depletion combined with 21 days of sorafenib treatment exerts a substantial antitumor effect in vivo. Interestingly, we showed that, upon exposure to sorafenib treatment, Notch3 depleted xenografts maintain lower levels of p21 and higher levels of pGSK3β^Ser9 than control xenografts. Thus, this study demonstrated that inhibition of Notch3 signaling prevents HCC-mediate drug resistance and sensitizes HCC cells to sorafenib. Finally, we validated our in vitro and in vivo results in primary human HCCs showing that Notch3 protein expression positively correlated with p21 protein expression and negatively correlated with pGSK3β^Ser9 expression. In conclusion, the results presented in this study demonstrated that Notch3 silencing enhances the effect of sorafenib by overcoming drug resistance. Notch3 inhibition in combination with sorafenib can be a promising strategy for treatment of HCC.

Liver cancer cells: targeting and prolonged-release drug carriers consisting of mesoporous silica nanoparticles and alginate microspheres

A new microsphere consisting of inorganic mesoporous silica nanoparticles (MSNs) and organic alginate (denoted as MSN@Alg) was successfully synthesized by air-dynamic atomization and applied to the intracellular drug delivery systems (DDS) of liver cancer cells with sustained release and specific targeting properties. MSN@Alg microspheres have the advantages of MSN and alginate, where MSN provides a large surface area for high drug loading and alginate provides excellent biocompatibility and COOH functionality for specific targeting. Rhodamine 6G was used as a model drug, and the sustained release behavior of the rhodamine 6G-loaded MSN@Alg microspheres can be prolonged up to 20 days. For targeting therapy, the anticancer drug doxorubicin was loaded into MSN@Alg microspheres, and the (lysine)4-tyrosine-arginine-glycine-aspartic acid (K₄YRGD) peptide was functionalized onto the surface of MSN@Alg for targeting liver cancer cells, hepatocellular carcinoma (HepG2). The results of the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay and confocal laser scanning microscopy indicate that the MSN@Alg microspheres were successfully uptaken by HepG2 without apparent cytotoxicity. In addition, the intracellular drug delivery efficiency was greatly enhanced (ie, 3.5-fold) for the arginine-glycine-aspartic acid (RGD)-labeled, doxorubicin-loaded MSN@Alg drug delivery system compared with the non-RGD case. The synthesized MSN@Alg microspheres show great potential as drug vehicles with high biocompatibility, sustained release, and targeting features for future intracellular DDS.

A mechanistic study on the cardiotoxicity of 5-fluorouracil in vitro and clinical and occupational perspectives

Fluoropyrimidines are key agents for the treatment of gastrointestinal tract adenocarcinomas. The possible cardiotoxic effects in patients and occupationally exposed workers are multifactorial and remain a puzzle to solve for investigators. In the present study, we study what cell death pathways and what doses can determine direct cardiotoxic effects of 5-fluorouracil (5-FU) and doxorubicin (DOXO) on rat cardiocytes (H9c2) and a human colon adenocarcinoma (HT-29) cell line, already reported to be sensitive to 5-FU. We have found that 5-FU induced 50% growth inhibition (IC:50) at 72 h with concentrations of 400 μM and 4 μM on H9c2 and HT-29, respectively. Moreover, we have found that the addition of Levofolinic Acid (LF) to 5-FU potentiated the growth inhibition induced by 5-FU. The growth inhibition induced by 5-FU alone or in combination with LF in cardiocytes was paralleled by an increase of thiobarbituric acid-reactive species (Tbars) and end products of nitric oxide (NO) suggesting the increase of the oxidative stress status in cardiocytes. Interestingly, these effects were strongly potentiated by the addition of LF, a biochemical modulator of 5-FU activity. Our data suggest that agents such as 5-FU different from anthracyclines, conventionally related to the induction of cardiotoxic effects, can also induce cardiocyte damage paralleled by oxidative stress. The strategies based upon the use of scavengers could be used in order to prevent this effect.

Animal models in studies of cardiotoxicity side effects from antiblastic drugs in patients and occupational exposed workers

Cardiotoxicity is an important side effect of cytotoxic drugs and may be a risk factor of long-term morbidity for both patients during therapy and also for staff exposed during the phases of manipulation of antiblastic drugs. The mechanism of cardiotoxicity studied in vitro and in vivo essentially concerns the formation of free radicals leading to oxidative stress, with apoptosis of cardiac cells or immunologic reactions, but other mechanisms may play a role in antiblastic-induced cardiotoxicity. Actually, some new cytotoxic drugs like trastuzumab and cyclopentenyl cytosine show cardiotoxic effects. In this report we discuss the different mechanisms of cardiotoxicity induced by antiblastic drugs assessed using animal models.