Sorafenib and 2-Deoxyglucose Synergistically Inhibit Proliferation of Both Sorafenib-Sensitive and -Resistant HCC Cells by Inhibiting ATP Production

Role of lactate and lactate metabolism in liver diseases (Review)

Lactate is a byproduct of glycolysis, and before the Warburg effect was revealed (in which glucose can be fermented in the presence of oxygen to produce lactate) it was considered a metabolic waste product. At present, lactate is not only recognized as a metabolic substrate that provides energy, but also as a signaling molecule that regulates cellular functions under pathophysiological conditions. Lactylation, a post‑translational modification, is involved in the development of various diseases, including inflammation and tumors. Liver disease is a major health challenge worldwide. In normal liver, there is a net lactate uptake caused by gluconeogenesis, exhibiting a higher net lactate clearance rate compared with any other organ. Therefore, abnormalities of lactate and lactate metabolism lead to the development of liver disease, and lactate and lactate metabolism‑related genes can be used for predicting the prognosis of liver disease. Targeting lactate production, regulating lactate transport and modulating lactylation may be potential treatment approaches for liver disease. However, currently there is not a systematic review that summarizes the role of lactate and lactate metabolism in liver diseases. In the present review, the role of lactate and lactate metabolism in liver diseases including liver fibrosis, non‑alcoholic fatty liver disease, acute liver failure and hepatocellular carcinoma was summarized with the aim to provide insights for future research.

Research progress in the metabolic reprogramming of hepatocellular carcinoma (Review)

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and its morbidity is increasing worldwide due to increasing prevalence. Metabolic reprogramming has been recognized as a hallmark of cancer and serves a role in cancer progression. Glucose, lipids and amino acids are three major components whose altered metabolism can directly affect the energy production of cells, including liver cancer cells. Nutrients and energy are indispensable for the growth and proliferation of cancer cells, thus altering the metabolism of hepatoma cells can inhibit the progression of HCC. The present review summarizes recent studies on tumour regulatory molecules, including numerous noncoding RNAs, oncogenes and tumour suppressors, which regulate the metabolic activities of glucose, lipids and amino acids by targeting key enzymes, signalling pathways or interactions between the two. These regulatory molecules can regulate the rapid proliferation of cancer cells, tumour progression and treatment resistance. It is thought that these tumour regulatory factors may serve as therapeutic targets or valuable biomarkers for HCC, with the potential to mitigate HCC drug resistance. Furthermore, the advantages and disadvantages of metabolic inhibitors as a treatment approach for HCC, as well as possible solutions are discussed, providing insights for developing more effective treatment strategies for HCC.

Signaling pathways in liver cancer: pathogenesis and targeted therapy

Liver cancer remains one of the most prevalent malignancies worldwide with high incidence and mortality rates. Due to its subtle onset, liver cancer is commonly diagnosed at a late stage when surgical interventions are no longer feasible. This situation highlights the critical role of systemic treatments, including targeted therapies, in bettering patient outcomes. Despite numerous studies on the mechanisms underlying liver cancer, tyrosine kinase inhibitors (TKIs) are the only widely used clinical inhibitors, represented by sorafenib, whose clinical application is greatly limited by the phenomenon of drug resistance. Here we show an in-depth discussion of the signaling pathways frequently implicated in liver cancer pathogenesis and the inhibitors targeting these pathways under investigation or already in use in the management of advanced liver cancer. We elucidate the oncogenic roles of these pathways in liver cancer especially hepatocellular carcinoma (HCC), as well as the current state of research on inhibitors respectively. Given that TKIs represent the sole class of targeted therapeutics for liver cancer employed in clinical practice, we have particularly focused on TKIs and the mechanisms of the commonly encountered phenomena of its resistance during HCC treatment. This necessitates the imperative development of innovative targeted strategies and the urgency of overcoming the existing limitations. This review endeavors to shed light on the utilization of targeted therapy in advanced liver cancer, with a vision to improve the unsatisfactory prognostic outlook for those patients.

EGR1 suppresses HCC growth and aerobic glycolysis by transcriptionally downregulating PFKL

BACKGROUND

Hepatocellular Carcinoma (HCC) is a matter of great global public health importance; however, its current therapeutic effectiveness is deemed inadequate, and the range of therapeutic targets is limited. The aim of this study was to identify early growth response 1 (EGR1) as a transcription factor target in HCC and to explore its role and assess the potential of gene therapy utilizing EGR1 for the management of HCC.

METHODS

In this study, both in vitro and in vivo assays were employed to examine the impact of EGR1 on the growth of HCC. The mouse HCC model and human organoid assay were utilized to assess the potential of EGR1 as a gene therapy for HCC. Additionally, the molecular mechanism underlying the regulation of gene expression and the suppression of HCC growth by EGR1 was investigated.

RESULTS

The results of our investigation revealed a notable decrease in the expression of EGR1 in HCC. The decrease in EGR1 expression promoted the multiplication of HCC cells and the growth of xenografted tumors. On the other hand, the excessive expression of EGR1 hindered the proliferation of HCC cells and repressed the development of xenografted tumors. Furthermore, the efficacy of EGR1 gene therapy was validated using in vivo mouse HCC models and in vitro human hepatoma organoid models, thereby providing additional substantiation for the anti-cancer role of EGR1 in HCC. The mechanistic analysis demonstrated that EGR1 interacted with the promoter region of phosphofructokinase-1, liver type (PFKL), leading to the repression of PFKL gene expression and consequent inhibition of PFKL-mediated aerobic glycolysis. Moreover, the sensitivity of HCC cells and xenografted tumors to sorafenib was found to be increased by EGR1.

CONCLUSION

Our findings suggest that EGR1 possesses therapeutic potential as a tumor suppressor gene in HCC, and that EGR1 gene therapy may offer benefits for HCC patients.

MAGOH promotes gastric cancer progression via hnRNPA1 expression inhibition-mediated RONΔ160/PI3K/AKT signaling pathway activation

BACKGROUND

Gastric cancer (GC) is associated with high mortality and heterogeneity and poses a great threat to humans. Gene therapies for the receptor tyrosine kinase RON and its spliceosomes are attracting increasing amounts of attention due to their unique characteristics. However, little is known about the mechanism involved in the formation of the RON mRNA alternative spliceosome RONΔ160.

METHODS

Fourteen human GC tissue samples and six normal gastric tissue samples were subjected to label-free relative quantitative proteomics analysis, and MAGOH was identified as a candidate protein for subsequent studies. The expression of MAGOH in clinical specimens was verified by quantitative real-time PCR and western blotting. We then determined the biological function of MAGOH in GC through in vitro and in vivo experiments. RNA pulldown, RNA sequencing and RNA immunoprecipitation (RIP) were subsequently conducted to uncover the underlying mechanism by which MAGOH regulated the formation of RONΔ160.

RESULTS

Proteomic analysis revealed that MAGOH, which is located at key nodes and participates in RNA processing and mRNA splicing, was upregulated in GC tissue and GC cell lines and was associated with poor prognosis. Functional analysis showed that MAGOH promoted the proliferation, migration and invasion of GC cells in vitro and in vivo. Mechanistically, MAGOH inhibited the expression of hnRNPA1 and reduced the binding of hnRNPA1 to RON mRNA, thereby promoting the formation of RONΔ160 to activate the PI3K/AKT signaling pathway and consequently facilitating GC progression.

CONCLUSIONS

Our study revealed that MAGOH could promote the formation of RONΔ160 and activate the PI3K/AKT signaling pathway through the inhibition of hnRNPA1 expression. We elucidate a novel mechanism and potential therapeutic targets for the growth and metastasis of GC based on the MAGOH-RONΔ160 axis, and these findings have important guiding significance and clinical value for the future development of effective therapeutic strategies for GC.

Glycolysis maintains AMPK activation in sorafenib-induced Warburg effect

Hepatocellular carcinoma (HCC) is the second deadly cancer in the world and still lacks curative treatment. Aerobic glycolysis, or Warburg effect, is a major resistance mechanism induced by first-line treatment of HCC, sorafenib, and is regulated by the master regulator of metabolism, AMPK. Activation of AMPK is required for resistance; however, activation dynamics of AMPK and its regulation is rarely studied. Engineering cells to express an AMPK activity biosensor, we monitor AMPK activation in single HCC cells in a high throughput manner during sorafenib-induced drug resistance. Sorafenib induces transient activation of AMPK, duration of which is dependent on glucose. Inhibiting glycolysis shortens AMPK activation; whereas increasing glycolysis increases its activation duration. Our data highlight that activation duration of AMPK is important for cancer evasion of therapeutic treatment and glycolysis is a key regulator of activation duration of AMPK.

Carvacrol enhances anti-tumor activity and mitigates cardiotoxicity of sorafenib in thioacetamide-induced hepatocellular carcinoma model through inhibiting TRPM7

AIMS

Sorafenib (Sora) represents one of the few effective drugs for the treatment of advanced hepatocellular carcinoma (HCC), while resistance and cardiotoxicity limit its therapeutic efficacy. This study investigated the effect of transient receptor potential melastatin 7 (TRPM7) inhibitor, carvacrol (CARV), on overcoming Sora resistance and cardiotoxicity in thioacetamide (TAA) induced HCC in rats.

MATERIALS AND METHODS

TAA (200 mg/kg/twice weekly, intraperitoneal) was administered for 16 weeks to induce HCC. Rats were treated with Sora (10 mg/Kg/day; orally) and CARV (15 mg/kg/day; orally) alone or in combination, for six weeks after HCC induction. Liver and heart functions, antioxidant capacity, and histopathology were performed. Apoptosis, proliferation, angiogenesis, metastasis, and drug resistance were assessed by quantitative real time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry.

KEY FINDINGS

CARV/Sora combination significantly improved survival rate, and liver functions, reduced Alpha-Fetoprotein level, and attenuated HCC progression compared with Sora group. CARV coadministration almost obviated Sora-induced changes in cardiac and hepatic tissues. The CARV/Sora combination suppressed drug resistance and stemness by downregulating ATP-binding cassette subfamily G member 2, NOTCH1, Spalt like transcription factor 4, and CD133. CARV boosted Sora antiproliferative and apoptotic activities by decreasing cyclin D1 and B-cell leukemia/lymphoma 2 and increasing BCL2-Associated X and caspase-3.

SIGNIFICANCE

CARV/Sora is a promising combination for tumor suppression and overcoming Sora resistance and cardiotoxicity in HCC by modulating TRPM7. To our best knowledge, this study represents the first study to investigate the efficiency of CARV/ Sora on the HCC rat model. Moreover, no previous studies have reported the effect of inhibiting TRPM7 on HCC.

2-Deoxy-D-Glucose: A Novel Pharmacological Agent for Killing Hypoxic Tumor Cells, Oxygen Dependence-Lowering in Covid-19, and Other Pharmacological Activities

The nonmetabolizable glucose analog 2-deoxy-D-glucose (2-DG) has shown promising pharmacological activities, including inhibition of cancerous cell growth and N-glycosylation. It has been used as a glycolysis inhibitor and as a potential energy restriction mimetic agent, inhibiting pathogen-associated molecular patterns. Radioisotope derivatives of 2-DG have applications as tracers. Recently, 2-DG has been used as an anti-COVID-19 drug to lower the need for supplemental oxygen. In the present review, various pharmaceutical properties of 2-DG are discussed.

Research progress of abnormal lactate metabolism and lactate modification in immunotherapy of hepatocellular carcinoma

Tumors meet their energy, biosynthesis, and redox demands through metabolic reprogramming. This metabolic abnormality results in elevated levels of metabolites, particularly lactate, in the tumor microenvironment. Immune cell reprogramming and cellular plasticity mediated by lactate and lactylation increase immunosuppression in the tumor microenvironment and are emerging as key factors in regulating tumor development, metastasis, and the effectiveness of immunotherapies such as immune checkpoint inhibitors. Reprogramming of glucose metabolism and the "Warburg effect" in hepatocellular carcinoma (HCC) lead to the massive production and accumulation of lactate, so lactate modification in tumor tissue is likely to be abnormal as well. This article reviews the immune regulation of abnormal lactate metabolism and lactate modification in hepatocellular carcinoma and the therapeutic strategy of targeting lactate-immunotherapy, which will help to better guide the medication and treatment of patients with hepatocellular carcinoma.

Role of hypoxia in the tumor microenvironment and targeted therapy

Tumor microenvironment (TME), which is characterized by hypoxia, widely exists in solid tumors. As a current research hotspot in the TME, hypoxia is expected to become a key element to break through the bottleneck of tumor treatment. More and more research results show that a variety of biological behaviors of tumor cells are affected by many factors in TME which are closely related to hypoxia. In order to inhibiting the immune response in TME, hypoxia plays an important role in tumor cell metabolism and anti-apoptosis. Therefore, exploring the molecular mechanism of hypoxia mediated malignant tumor behavior and therapeutic targets is expected to provide new ideas for anti-tumor therapy. In this review, we discussed the effects of hypoxia on tumor behavior and its interaction with TME from the perspectives of immune cells, cell metabolism, oxidative stress and hypoxia inducible factor (HIF), and listed the therapeutic targets or signal pathways found so far. Finally, we summarize the current therapies targeting hypoxia, such as glycolysis inhibitors, anti-angiogenesis drugs, HIF inhibitors, hypoxia-activated prodrugs, and hyperbaric medicine.

Adapalene and Doxorubicin Synergistically Promote Apoptosis of TNBC Cells by Hyperactivation of the ERK1/2 Pathway Through ROS Induction

Doxorubicin is a commonly used chemotherapeutic agent to treat several malignancies, including aggressive tumors like triple-negative breast cancer. It has a limited therapeutic index owing to its extreme toxicity and the emergence of drug resistance. As a result, there is a pressing need to find innovative drugs that enhance the effectiveness of doxorubicin while minimizing its toxicity. The rationale of the present study is that combining emerging treatment agents or repurposed pharmaceuticals with doxorubicin might increase susceptibility to therapeutics and the subsequent establishment of improved pharmacological combinations for treating triple-negative breast cancer. Additionally, combined treatment will facilitate dosage reduction, reducing the toxicity associated with doxorubicin. Recently, the third-generation retinoid adapalene was reported as an effective anticancer agent in several malignancies. This study aimed to determine the anticancer activity of adapalene in TNBC cells and its effectiveness in combination with doxorubicin, and the mechanistic pathways in inhibiting tumorigenicity. Adapalene inhibits tumor cell growth and proliferation and acts synergistically with doxorubicin in inhibiting growth, colony formation, and migration of TNBC cells. Also, the combination of adapalene and doxorubicin enhanced the accumulation of reactive oxygen species triggering hyperphosphorylation of Erk1/2 and caspase-dependent apoptosis. Our results demonstrate that adapalene is a promising antitumor agent that may be used as a single agent or combined with present therapeutic regimens for TNBC treatment.

Broad Transcriptomic Impact of Sorafenib and Its Relation to the Antitumoral Properties in Liver Cancer Cells

Simple Summary

Hepatocellular carcinoma (HCC) is the fourth most frequent cause of cancer-related mortality worldwide. While ablation, resection and orthotopic liver transplantation are indicated at an early stage of the disease, Sorafenib (Sfb) is the current most administrated first-line treatment for advanced HCC, even though its therapeutic benefit is limited due to the appearance of resistance. Deep knowledge on the molecular consequences of Sfb-treatment is essentially required for optimizing novel therapeutic strategies to improve the outcomes for patients with advanced HCC. In this study, we analyzed differential gene expression changes in two well characterized liver cancer cell lines upon a Sfb-treatment, demonstrating that both lines responded similarly to the treatment. Our results provide valuable information on the molecular action of Sfb on diverse cellular fundamental processes such as DNA repair, translation and proteostasis and identify rationalization issues that could provide a different therapeutic perspective to Sfb.

Abstract

Hepatocellular carcinoma (HCC) is one of the most frequent and essentially incurable cancers in its advanced stages. The tyrosine kinase inhibitor Sorafenib (Sfb) remains the globally accepted treatment for advanced HCC. However, the extent of its therapeutic benefit is limited. Sfb exerts antitumor activity through its cytotoxic, anti-proliferative and pro-apoptotic roles in HCC cells. To better understand the molecular mechanisms underlying these effects, we used RNA sequencing to generate comprehensive transcriptome profiles of HepG2 and SNU423, hepatoblastoma- (HB) and HCC-derived cell lines, respectively, following a Sfb treatment at a pharmacological dose. This resulted in similar alterations of gene expression in both cell lines. Genes functionally related to membrane trafficking, stress-responsible and unfolded protein responses, circadian clock and activation of apoptosis were predominantly upregulated, while genes involved in cell growth and cycle, DNA replication and repair, ribosome biogenesis, translation initiation and proteostasis were downregulated. Our results suggest that Sfb causes primary effects on cellular stress that lead to upregulation of selective responses to compensate for its negative effect and restore homeostasis. No significant differences were found specifically affecting each cell line, indicating the robustness of the Sfb mechanism of action despite the heterogeneity of liver cancer. We discuss our results on terms of providing rationalization for possible strategies to improve Sfb clinical outcomes.

2-Deoxy-D-glucose impedes T cell-induced apoptosis of keratinocytes in oral lichen planus

Oral lichen planus (OLP) is a T cell–mediated immunoinflammatory disease. Glycolysis plays an essential role in T‐cell immune responses. Blocking glycolytic pathway in activated T cells represents a therapeutic strategy for restraint of immunologic process in autoimmune disorders. 2‐Deoxy‐D‐glucose (2‐DG) has been widely used to probe into glycolysis in immune cells. This study was aimed to explore the role of glycolysis inhibition by 2‐DG on regulating immune responses of OLP‐derived T cells. We observed that lactic dehydrogenase A (LDHA) expression was elevated in OLP lesions and local T cells. 2‐DG inhibited the expression of LDHA, p‐mTOR, Hif1α and PLD2 in T cells; meanwhile, it decreased proliferation and increased apoptosis of T cells. T cells treated by 2‐DG showed lower LDHA expression and elevated apoptosis, resulting in a reduced apoptotic population of keratinocytes that were co‐cultured with them, which was related to the decreased levels of IFN‐γ in co‐culture system. Rapamycin enhanced the effects of 2‐DG on immune responses between T cells and keratinocytes. Thus, these findings indicated that OLP‐derived T cells might be highly dependent upon high glycolysis for proliferation, and 2‐DG treatment combined with rapamycin might be an option to alleviate T‐cell responses, contributing to reducing apoptosis of keratinocytes.

Hypoxia, Metabolic Reprogramming, and Drug Resistance in Liver Cancer

Hypoxia, low oxygen (O₂) level, is a hallmark of solid cancers, especially hepatocellular carcinoma (HCC), one of the most common and fatal cancers worldwide. Hypoxia contributes to drug resistance in cancer through various molecular mechanisms. In this review, we particularly focus on the roles of hypoxia-inducible factor (HIF)-mediated metabolic reprogramming in drug resistance in HCC. Combination therapies targeting hypoxia-induced metabolic enzymes to overcome drug resistance will also be summarized. Acquisition of drug resistance is the major cause of unsatisfactory clinical outcomes of existing HCC treatments. Extra efforts to identify novel mechanisms to combat refractory hypoxic HCC are warranted for the development of more effective treatment regimens for HCC patients.

Molecular and Metabolic Reprogramming: Pulling the Strings Toward Tumor Metastasis

Metastasis is a major hurdle to the efficient treatment of cancer, accounting for the great majority of cancer-related deaths. Although several studies have disclosed the detailed mechanisms underlying primary tumor formation, the emergence of metastatic disease remains poorly understood. This multistep process encompasses the dissemination of cancer cells to distant organs, followed by their adaptation to foreign microenvironments and establishment in secondary tumors. During the last decades, it was discovered that these events may be favored by particular metabolic patterns, which are dependent on reprogrammed signaling pathways in cancer cells while they acquire metastatic traits. In this review, we present current knowledge of molecular mechanisms that coordinate the crosstalk between metastatic signaling and cellular metabolism. The recent findings involving the contribution of crucial metabolic pathways involved in the bioenergetics and biosynthesis control in metastatic cells are summarized. Finally, we highlight new promising metabolism-based therapeutic strategies as a putative way of impairing metastasis.

The Yunnan national medicine Maytenus compound inhibits the proliferation of hepatocellular carcinoma (HCC) by suppressing the activation of the EGFR-PI3K-AKT signaling pathway

Objective: To investigate the effects of Maytenus compound on the proliferation of hepatocellular carcinoma (HCC) cells in vitro and in vivo and to explore the underlying mechanism. Methods: The half maximal inhibitory concentration (IC50) values of Maytenus compound in HepG2 and BEL-7402 cells were determined by the MTS assay. HepG2 and BEL-7402 cells were treated with different concentrations of Maytenus compound. MTS assays, colony formation assays and cell cycle analyses were performed to clarify the inhibitory effect of Maytenus compound on the proliferation of HepG2 and BEL-7402 cells in vitro. After subcutaneous injection of HepG2 cells, nude mice were randomly divided into a vehicle control group and a drug intervention group, which were intragastrically administered ddH2O or Maytenus compound, respectively. The inhibitory effect of Maytenus compound on the proliferation of HepG2 cells in vivo was analyzed using subcutaneous tumor growth curves, tumor weight, the tumor growth inhibition rate and the immunohistochemical detection of BrdU-labeled cells in S phase. The organ toxicity of Maytenus compound was initially evaluated by comparing the weight difference and organ index of the two groups of nude mice. The main proteins in the EGFR-PI3K-AKT signaling pathway were detected by Western blot after Maytenus compound intervention in vivo and in vitro. Results: Maytenus compound showed favorable antiproliferation activity against HepG2 and BEL-7402 cells with IC50 values of 79.42±11.71 µg/mL and 78.48±8.87 µg/mL, respectively. MTS assays, colony formation assays and cell cycle analyses showed that Maytenus compound at different concentration gradients within the IC50 concentration range significantly suppressed the proliferation of HepG2 and BEL-7402 cells in vitro and inhibited cell cycle progression from G1 to S phase. Additionally, Maytenus compound, at an oral dose of 2.45 g/kg, dramatically inhibited, without obvious organ toxicity, the proliferation of subcutaneous tumors formed by HepG2 cells in nude mice. In addition, the tumor growth inhibition rate for Maytenus compound was 66.94%. Furthermore, Maytenus compound inhibited the proliferation of liver orthotopic transplantation tumors in nude mice. Western blot analysis showed that Maytenus compound significantly downregulated the expression of p-EGFR, p-PI3K, and p-AKT and upregulated the expression of p-FOXO3a, p27, and p21 in vivo and in vitro. Conclusion: Maytenus compound significantly inhibited the proliferation of HCC cells in vitro and in vivo. The downregulation of the EGFR-PI3K-AKT signaling pathway and subsequent inhibition of cell cycle progression from G1 to S phase is one of the possible mechanisms. Maytenus compound has a high tumor growth inhibition rate and has no obvious organ toxicity, which may make it a potential anti-HCC drug, but the results from this study need to be confirmed by further clinical trials in HCC patients.

Propofol inhibits proliferation, migration, invasion and promotes apoptosis by regulating HOST2/JAK2/STAT3 signaling pathway in ovarian cancer cells

We aimed to investigate the effect of propofol on the growth of human ovarian cancer cells ES2 and OVCAR-3 in vitro by regulating long non-coding RNA HOST2 (human ovarian cancer-specific transcript 2) and the inhibition of JAK2/STAT3 signaling pathway. In the present study, ES-2 and OVCAR-3 cells were firstly treated with different concentrations of propofol (0, 1, 5 and 10 μg/ml). The expression of HOST2 in ES-2 and OVCAR-3 cells were detected by quantitative reverse transcription-PCR (qRT-PCR). Then, the expression of HOST2 was changed by transfection of HOST2 overexpression plasmid into ES-2 and OVCAR-3 cells. Cell proliferation, migration, invasion and apoptosis were performed using CCK-8, wound-healing, Transwell assays and Flow Cytometry. Western blot analysis was performed to detect the expressions of apoptosis-associated proteins and JAK2/STAT3 pathway-related proteins. Results showed that cell viability and intracellular HOST2 expression in ES-2 and OVCAR-3 cells were decreased gradually with the increase of propofol concentration in a dose-dependent manner. Compared with the propofol group, overexpression of HOST2 significantly promoted the cell proliferation, migration, invasion and inhibited apoptosis, and ameliorated the inhibitory effect of propofol on the growth of tumor cells. Western blot analysis showed that compared with propofol group, the expression of Bcl-2 was significantly increased whereas Bax and the ratio of Cleaved caspase3/caspase3 were significantly decreased in pcDNA-HOST2 group. In addition, overexpression of HOST2 significantly enhanced the phosphorylation level of JAK2 and STAT3, and reduced the suppressive effect of propofol on JAK2/STAT3 signaling. Our results illustrated that propofol could significantly inhibit the proliferation, migration, invasion and induce apoptosis of ES-2 and OVCAR-3 cells by downregulating HOST2. The regulation mechanism may be achieved by inhibiting the activation of JAK2/STAT3 signaling pathway.

Increased photodynamic therapy sensitization in tumors using a nitric oxide-based nanoplatform with ATP-production blocking capability

Photodynamic therapy (PDT) efficacy in cancer cells is affected by sub-physiological hypoxia caused by dysregulated and “chaotic” tumor microvasculature. However, current traditional O₂-replenishing strategies are undergoing their own intrinsic deficiencies. In addition, resistance mechanisms activated during PDT also lead the present situation far from satisfactory.

Methods: We propose a nitric oxide (NO)-based theranostic nanoplatform by using biocompatible poly-lactic-co-glycolic acid nanoparticles (PLGA NPs) as carriers, in which the outer polymeric layer embeds chlorin e6 (Ce6) and incorporates L-Arginine (L-Arg). This nanoplatform (L-Arg@Ce6@P NPs) can reduce hyperactive O₂ metabolism of tumor cells by NO-mediated mitochondrial respiration inhibition, which should raise endogenous O₂ tension to counteract hypoxia. Furthermore, NO can also hinder oxidative phosphorylation (OXPHOS) which should cause intracellular adenosine triphosphate (ATP) depletion, inhibiting tumor cells proliferation and turning cells more sensitive to PDT.

Results: When the L-Arg@Ce6@P NPs accumulate in solid tumors by the enhanced permeability and retention (EPR) effect, locally released L-Arg is oxidized by the abundant H₂O₂ to produce NO. In vitro experiments suggest that NO can retard hypoactive O₂ metabolism and save intracellular O₂ for enhancing PDT efficacy under NIR light irradiation. Also, lower intracellular ATP hinders proliferation of DNA, improving PDT sensitization. PDT phototherapeutic efficacy increased by combining these two complementary strategies in vitro/in vivo.

Conclusion: We show that this NO-based nanoplatform can be potentially used to alleviate hypoxia and sensitize tumor cells to amplify the efficacy of phototherapy guided by photoacoustic (PA) imaging.

The oncogenic and clinical implications of lactate induced immunosuppression in the tumour microenvironment

The tumour microenvironment is of critical importance in cancer development and progression and includes the surrounding stromal and immune cells, extracellular matrix, and the milieu of metabolites and signalling molecules in the intercellular space. To support sustained mitotic activity cancer cells must reconfigure their metabolic phenotype. Lactate is the major by-product of such metabolic alterations and consequently, accumulates in the tumour. Lactate actively contributes to immune evasion, a hallmark of cancer, by directly inhibiting immune cell cytotoxicity and proliferation. Furthermore, lactate can recruit and induce immunosuppressive cell types, such as regulatory T cells, tumour-associated macrophages, and myeloid-derived suppressor cells which further suppress anti-tumour immune responses. Given its roles in oncogenesis, measuring intratumoural and systemic lactate levels has shown promise as a both predictive and prognostic biomarker in several cancer types. The efficacies of many anti-cancer therapies are limited by an immunosuppressive TME in which lactate is a major contributor, therefore, targeting lactate metabolism is a priority. Developing inhibitors of key proteins in lactate metabolism such as GLUT1, hexokinase, LDH, MCT and HIF have shown promise in preclinical studies, however there is a corresponding lack of success in human trials so far. This may be explained by a weakness of preclinical models that fail to reproduce the complexities of metabolic interactions in natura. The future of these therapies may be as an adjunct to more conventional treatments.

Development and Evaluation of Paclitaxel and Curcumin Dry Powder for Inhalation Lung Cancer Treatment

Despite the effort to develop efficient targeted drug delivery for lung cancer treatment, the outcome remains unsatisfactory with a survival rate of 15% after 5 years of diagnosis. Inhalation formulation is an ideal alternative that could ensure the direct deposition of chemotherapeutics to the lungs. However, the design of an inhalable formulation that could simultaneously achieve a high local chemotherapeutic dose to the solid tumor and exert low pulmonary toxicities is a challenge, as the presence of 10–30% of chemotherapeutics in the lung is sufficient to induce toxicity. Therefore, this study aimed to develop a simple dry powder inhalation (DPI) formulation containing a model chemotherapeutic agent (paclitaxel, PTX) and a natural antioxidant (curcumin, CUR) that acts to protect healthy lung cells from injury during direct lung delivery. The co-jet-milling of CUR and PTX resulted in formulations with suitable aerosol performance, as indicated in the high fine particle fractions (FPF) (>60%) and adequate mass median aerodynamic diameter (MMAD). The CUR/PTX combination showed a more potent cytotoxic effect against lung cancer cells. This is evident from the induction of apoptosis/necrotic cell death and G2/M cell cycle arrests in both A549 and Calu-3 cells. The increased intracellular ROS, mitochondrial depolarization and reduced ATP content in A549 and Calu-3 cells indicated that the actions of CUR and PTX were associated with mitochondrial oxidative stress. Interestingly, the presence of CUR is crucial to neutralize the cytotoxic effects of PTX against healthy cells (Beas-2B), and this is dose-dependent. This study presents a simple approach to formulating an effective DPI formulation with preferential cytotoxicity towards lung cancer.

Transcriptomics-Based Drug Repurposing Approach Identifies Novel Drugs against Sorafenib-Resistant Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma (HCC), a type of liver cancer, remains a treatment challenge due to late detection and resistance to currently approved drugs. It takes 15–20 years for a single new drug to become FDA approved. The purpose of this study was to expedite identification of novel drugs against drug-resistant HCC. For this, we matched gene expression alterations in resistant HCC with gene expression changes caused by treatment of cancer cells with drugs already FDA approved for other diseases to find the drug that can reverse the resistance-related changes. Among the identified drugs, we validated the growth inhibitory effect of two drugs, identified their mechanism in HCC and, thus, provided proof of concept evidence for validity of this drug repurposing approach with potential for use in personalized medicine.

Abstract

Objective: Hepatocellular carcinoma (HCC) is frequently diagnosed in patients with late-stage disease who are ineligible for curative surgical therapies. The majority of patients become resistant to sorafenib, the only approved first-line therapy for advanced cancer, underscoring the need for newer, more effective drugs. The purpose of this study is to expedite identification of novel drugs against sorafenib resistant (SR)-HCC. Methods: We employed a transcriptomics-based drug repurposing method termed connectivity mapping using gene signatures from in vitro-derived SR Huh7 HCC cells. For proof of concept validation, we focused on drugs that were FDA-approved or under clinical investigation and prioritized two anti-neoplastic agents (dasatinib and fostamatinib) with targets associated with HCC. We also prospectively validated predicted gene expression changes in drug-treated SR Huh7 cells as well as identified and validated the targets of Fostamatinib in HCC. Results: Dasatinib specifically reduced the viability of SR-HCC cells that correlated with up-regulated activity of SRC family kinases, its targets, in our SR-HCC model. However, fostamatinib was able to inhibit both parental and SR HCC cells in vitro and in xenograft models. Ingenuity pathway analysis of fostamatinib gene expression signature from LINCS predicted JAK/STAT, PI3K/AKT, ERK/MAPK pathways as potential targets of fostamatinib that were validated by Western blot analysis. Fostamatinib treatment reversed the expression of genes that were deregulated in SR HCC. Conclusion: We provide proof of concept evidence for the validity of this drug repurposing approach for SR-HCC with implications for personalized medicine.

New insights on sorafenib resistance in liver cancer with correlation of individualized therapy

Liver cancer is highly malignant and insensitive to cytotoxic chemotherapy and is associated with very poor patient prognosis. In 2007, the small-molecule targeted drug sorafenib was approved for the treatment of advanced liver cancer. In the subsequent ten years, sorafenib has been the only first-line therapeutic targeted drug for advanced hepatocellular carcinoma (HCC). However, a number of clinical studies show that a considerable percentage of patients with liver cancer are insensitive to sorafenib. The number of patients who actually benefit significantly from sorafenib treatment is very limited, and the overall efficacy of sorafenib is far from satisfactory, which has attracted the attention of researchers. Based on previous studies and reports, this article reviews the potential mechanisms of sorafenib resistance (SR) and summarizes the biomarkers and clinicopathological indicators that might be used for predicting sorafenib response and developing personalized therapy.

Is the era of sorafenib over? A review of the literature

Hepatocellular carcinoma (HCC) is one of the most severe diseases worldwide. For the different stages of HCC, there are different clinical treatment strategies, such as surgical therapy for the early stage, and transarterial chemoembolization (TACE) and selective internal radiation therapy (SIRT) for intermediate-stage disease. Systemic treatment, which uses mainly targeted drugs, is the standard therapy against advanced HCC. Sorafenib is an important first-line therapy for advanced HCC. As a classically effective drug, sorafenib can increase overall survival markedly. However, it still has room for improvement because of the heterogeneity of HCC and acquired resistance. Scientists have reported the acquired sorafenib resistance is associated with the anomalous expression of certain genes, most of which are also related with HCC onset and development. Combining sorafenib with inhibitors targeting these genes may be an effective treatment. Combined treatment may not only overcome drug resistance, but also inhibit the expression of carcinoma-related genes. This review focuses on the current status of sorafenib in advanced HCC, summarizes the inhibitors that can combine with sorafenib in the treatment against HCC, and provides the rationale for clinical trials of sorafenib in combination with other inhibitors in HCC. The era of sorafenib in the treatment of HCC is far from over, as long as we find better methods of medication.

2-Deoxy-D-glucose enhances the anti-cancer effects of idarubicin on idarubicin-resistant P388 leukemia cells

Cancer cells switch from mitochondrial oxidative phosphorylation to glycolysis, even in the presence of normal oxygen concentrations. Inhibition of the glycolytic pathway is therefore a critical strategy in cancer therapy. A non-metabolic glucose analog, 2-deoxy-D-glucose (2-DG), has been the focus of research on glycolytic inhibitors for use in cancer treatment. The current study examined the anti-cancer effects of 2-DG on idarubicin (IDA)-resistant P388 (P388/IDA) leukemia cells. P388/IDA cells were established following continuous exposure of IDA to P388 cells. Characterization of P388/IDA cells revealed increased lactate production and glucose consumption compared with P388 parent cells. The results of a cell viability assay determined that 2-DG induces higher toxicity in P388/IDA cells compared with P388 cells. Although 2-DG also exhibits endoplasmic reticulum (ER) stress-inducing activity, the cytotoxic effect of the ER stress inducer, tunicamycin, on P388/IDA cells was lower than that of P388 cells. A combination of 2-DG and IDA enhanced P388/IDA cell death compared with each agent alone. The results indicated that P388 cells activated glycolysis after acquiring IDA resistance and therefore, inhibition of the glycolytic pathway via 2-DG might be a useful strategy for cancer therapy against IDA- resistant leukemia cells.

Redox Homeostasis and Metabolism in Cancer: A Complex Mechanism and Potential Targeted Therapeutics

Reactive Oxygen Species or "ROS" encompass several molecules derived from oxygen that can oxidize other molecules and subsequently transition rapidly between species. The key roles of ROS in biological processes are cell signaling, biosynthetic processes, and host defense. In cancer cells, increased ROS production and oxidative stress are instigated by carcinogens, oncogenic mutations, and importantly, metabolic reprograming of the rapidly proliferating cancer cells. Increased ROS production activates myriad downstream survival pathways that further cancer progression and metastasis. In this review, we highlight the relation between ROS, the metabolic programing of cancer, and stromal and immune cells with emphasis on and the transcription machinery involved in redox homeostasis, metabolic programing and malignant phenotype. We also shed light on the therapeutic targeting of metabolic pathways generating ROS as we investigate: Orlistat, Biguandes, AICAR, 2 Deoxyglucose, CPI-613, and Etomoxir.

Microbiota-derived SSL6 enhances the sensitivity of hepatocellular carcinoma to sorafenib by down-regulating glycolysis

Enhancing the sensitivity of hepatocellular carcinoma (HCC) cells to sorafenib (SFN) is an essential clinical bottleneck to be solved. Here we report that the expression of CD47 negatively correlated with HCC sensitivity to SFN. The microbiota-derived Staphylococcal superantigen-like protein 6 (SSL6) inhibited CD47 and promoted SFN-induced apoptosis of HCC cells Huh-7 and MHCC97H. Mechanistically, the sensitivity of HCC cells to SFN was inhibited by elevated Warburg effect (glycolysis), and SSL6 down-regulated PI3K/Akt-mediated glycolysis by blocking CD47. Knockdown of CD47 also dampened glycolysis and sensitized HCC cells to SFN. Moreover, SFN-resistant HCC cells exhibited enhanced glycolysis and CD47 expression. SSL6 significantly re-sensitized the resistant HCC cells to SFN. More importantly, we identified the anti-tumor effect of SSL6 in combination with SFN in HCC-bearing mice. Our results clarify the mechanism by which SSL6 enhances SFN sensitivity in HCC cells, providing a molecular basis for combination targeted therapy with microbiota-derived SSL6 to treat HCC.

Simvastatin re-sensitizes hepatocellular carcinoma cells to sorafenib by inhibiting HIF-1α/PPAR-γ/PKM2-mediated glycolysis

BACKGROUND

Hepatocellular carcinoma (HCC) is a common primary malignant tumor which usually progresses to an advanced stage because of late diagnosis. Sorafenib (Sora) is a first line medicine for advanced stage HCC; however, it has been faced with enormous resistance. Simvastatin (Sim) is a cholesterol-lowering drug and has been reported to inhibit tumor growth. The present study aims to determine whether Sora and Sim co-treatment can improve Sora resistance in HCC.

METHODS

The HCC cell line LM3 and an established Sora-resistant LM3 cell line (LM3-SR) were used to study the relationship between Sora resistance and aerobic glycolysis. Cell proliferation, apoptosis and glycolysis levels were analyzed by western blotting, flow cytometry analysis and biomedical tests. A xenograft model was also used to examine the effect of Sim in vivo. Detailed mechanistic studies were also undertaken by the use of activators and inhibitors, and lentivirus transfections.

RESULTS

Our results demonstrated that the resistance to Sora was associated with enhanced aerobic glycolysis levels. Furthermore, LM3-SR cells were more sensitive to Sim than LM3 cells, suggesting that combined treatment with both Sora and Sim could enhance the sensitivity of LM3-SR cells to Sora. This finding may be due to the suppression of the HIF-1α/PPAR-γ/PKM2 axis.

CONCLUSIONS

Simvastatin can inhibit the HIF-1α/PPAR-γ/PKM2 axis, by suppressing PKM2-mediated glycolysis, resulting in decreased proliferation and increased apoptosis in HCC cells, and re-sensitizing HCC cells to Sora.

Competitive glucose metabolism as a target to boost bladder cancer immunotherapy

Bladder cancer - the tenth most frequent cancer worldwide - has a heterogeneous natural history and clinical behaviour. The predominant histological subtype, urothelial bladder carcinoma, is characterized by high recurrence rates, progression and both primary and acquired resistance to platinum-based therapy, which impose a considerable economic burden on health-care systems and have substantial effects on the quality of life and the overall outcomes of patients with bladder cancer. The incidence of urothelial tumours is increasing owing to population growth and ageing, so novel therapeutic options are vital. Based on work by The Cancer Genome Atlas project, which has identified targetable vulnerabilities in bladder cancer, immune checkpoint inhibitors (ICIs) have arisen as an effective alternative for managing advanced disease. However, although ICIs have shown durable responses in a subset of patients with bladder cancer, the overall response rate is only ~15-25%, which increases the demand for biomarkers of response and therapeutic strategies that can overcome resistance to ICIs. In ICI non-responders, cancer cells use effective mechanisms to evade immune cell antitumour activity; the overlapping Warburg effect machinery of cancer and immune cells is a putative determinant of the immunosuppressive phenotype in bladder cancer. This energetic interplay between tumour and immune cells leads to metabolic competition in the tumour ecosystem, limiting nutrient availability and leading to microenvironmental acidosis, which hinders immune cell function. Thus, molecular hallmarks of cancer cell metabolism are potential therapeutic targets, not only to eliminate malignant cells but also to boost the efficacy of immunotherapy. In this sense, integrating the targeting of tumour metabolism into immunotherapy design seems a rational approach to improve the therapeutic efficacy of ICIs.

The microenvironmental and metabolic aspects of sorafenib resistance in hepatocellular carcinoma

In most cases, sorafenib-resistant HCC cells exhibit significant mesenchymal phenotype and stemness features. In this context, tumor cells might undergo cell fate transition in response to sorafenib or other targeted drugs in the presence or absence of genetic mutations. Therefore, understanding the major characteristics of drug-resistant cells state helps to discover new treatments that overcome drug resistance. To note, little is known about the metabolic or microenvironmental aspects of the certain tumor cell states beyond the genome. This review mainly focuses on the underlying mechanisms of acquired sorafenib resistance based on CSCs and EMT models, which explain tumor heterogeneity and have been considered the major cause of secondary sorafenib resistance. In particular, it discusses how the tumor microenvironment and tumor metabolism regulate cell stemness, mesenchymal state, and sorafenib resistance through epigenetic regulations, and provides reliable targets that might have synergetic effect with sorafenib.

2-Deoxy-d-Glucose and Its Analogs: From Diagnostic to Therapeutic Agents

The ability of 2-deoxy-d-glucose (2-DG) to interfere with d-glucose metabolism demonstrates that nutrient and energy deprivation is an efficient tool to suppress cancer cell growth and survival. Acting as a d-glucose mimic, 2-DG inhibits glycolysis due to formation and intracellular accumulation of 2-deoxy-d-glucose-6-phosphate (2-DG6P), inhibiting the function of hexokinase and glucose-6-phosphate isomerase, and inducing cell death. In addition to glycolysis inhibition, other molecular processes are also affected by 2-DG. Attempts to improve 2-DG’s drug-like properties, its role as a potential adjuvant for other chemotherapeutics, and novel 2-DG analogs as promising new anticancer agents are discussed in this review.

Ibrutinib Potentiates Antihepatocarcinogenic Efficacy of Sorafenib by Targeting EGFR in Tumor Cells and BTK in Immune Cells in the Stroma

Hepatocellular carcinoma (HCC), the most prevalent primary liver cancer, is a leading cause of cancer-related death worldwide because of rising incidence and limited therapy. Although treatment with sorafenib or lenvatinib is the standard of care in patients with advanced-stage HCC, the survival benefit from sorafenib is limited due to low response rate and drug resistance. Ibrutinib, an irreversible tyrosine kinase inhibitor (TKI) of the TEC (e.g., BTK) and ErbB (e.g., EGFR) families, is an approved treatment for B-cell malignancies. Here, we demonstrate that ibrutinib inhibits proliferation, spheroid formation, and clonogenic survival of HCC cells, including sorafenib-resistant cells. Mechanistically, ibrutinib inactivated EGFR and its downstream Akt and ERK signaling in HCC cells, and downregulated a set of critical genes involved in cell proliferation, migration, survival, and stemness, and upregulated genes promoting differentiation. Moreover, ibrutinib showed synergy with sorafenib or regorafenib, a sorafenib congener, by inducing apoptosis of HCC cells. In vivo, this TKI combination significantly inhibited HCC growth and prolonged survival of immune-deficient mice bearing human HCCLM3 xenograft tumors and immune-competent mice bearing orthotopic mouse Hepa tumors at a dose that did not exhibit systemic toxicity. In immune-competent mice, the ibrutinib-sorafenib combination reduced the numbers of BTK⁺ immune cells in the tumor microenvironment. Importantly, we found that the BTK⁺ immune cells were also enriched in the tumor microenvironment in a subset of primary human HCCs. Collectively, our findings implicate BTK signaling in hepatocarcinogenesis and support clinical trials of the sorafenib-ibrutinib combination for this deadly disease.

Nanomedicine as a putative approach for active targeting of hepatocellular carcinoma

The effectiveness of chemotherapy in hepatocellular carcinoma (HCC) is restricted by chemo-resistance and systemic side effects. To improve the efficacy and safety of chemotherapeutics in HCC management, scientists have attempted to deliver these drugs to malignant tissues using targeted carriers as nanoparticles (NPs). Among the three types of NPs targeting (active, passive, and stimuli-responsive), active targeting is the most commonly investigated in HCC treatment. Despite the observed promising results so far, clinical research on nanomedicine targeting for HCC treatment still faces many challenges.These include batch-to-batch physicochemical properties' variations, limiting large scale production and insufficient data on human and environmental toxicities. This review summarized the characteristics of different nanocarriers, ligands, targeted receptors on HCC cells and provided recommendations to overcome the challenges, facing this novel line of treatment for HCC.

Hexokinase-II Inhibition Synergistically Augments the Anti-tumor Efficacy of Sorafenib in Hepatocellular Carcinoma

This study aimed to examine whether inhibition of hexokinase (HK)-II activity enhances the efficacy of sorafenib in in-vivo models of hepatocellular carcinoma (HCC), and to evaluate the prognostic implication of HK-II expression in patients with HCC. We used 3-bromopyruvate (3-BP), a HK-II inhibitor to target HK-II. The human HCC cell line was tested as both subcutaneous and orthotopic tumor xenograft models in BALB/c nu/nu mice. The prognostic role of HK-II was evaluated in data from HCC patients in The Cancer Genome Atlas (TCGA) database and validated in patients treated with sorafenib. Quantitative real-time PCR, western blot analysis, and immunohistochemical staining revealed that HK-II expression is upregulated in the presence of sorafenib. Further analysis of the endoplasmic reticulum-stress network model in two different murine HCC models showed that the introduction of additional stress by 3-BP treatment synergistically increased the in vivo/vitro efficacy of sorafenib. We found that HCC patients with increased HK-II expression in the TCGA database showed poor overall survival, and also confirmed similar results for TCGA database HCC patients who had undergone sorafenib treatment. These results suggest that HK-II is a promising therapeutic target to enhance the efficacy of sorafenib and that HK-II expression might be a prognostic factor in HCC.

Oxidized Vitamin C (DHA) Overcomes Resistance to EGFR-targeted Therapy of Lung Cancer through Disturbing Energy Homeostasis

Switching aerobic respiration to anaerobic glycolysis of cancer cells plays an important role in development and progression of acquired resistance. Since vitamin C enabled the inhibition of glycolysis of cancer cells, and erlotinib-resistant sub-line of HCC827 (ER6 cells) switched its metabolic features to higher glycolysis for survival, we hypothesize that vitamin C is able to inhibit glycolysis of ER6 cells. In this study, we found that both reduced vitamin C and oxidized vitamin C (DHA) could selectively suppress the viability of ER6 cells. DHA was efficient in inhibiting glycolysis and leading to energy crisis, which could be one mechanism for overcoming drug resistance to erlotinib of ER6 cells. Our data suggest that applying DHA could be a novel treatment strategy for NSCLC with acquired resistance to targeted therapy.

Deoxynivalenol Affects Cell Metabolism and Increases Protein Biosynthesis in Intestinal Porcine Epithelial Cells (IPEC-J2): DON Increases Protein Biosynthesis

Deoxynivalenol (DON) is a toxin found in cereals as well as in processed products such as pasta, and causes substantial economic losses for stock breeding as it induces vomiting, reduced feeding, and reduced growth rates in piglets. Oxidative phosphorylation, TCA-cycle, transcription, and translation have been hypothesized to be leading pathways that are affected by DON. We used an application of high and low glucose to examine oxidative phosphorylation and anaerobic glycolysis. A change in the metabolic status of IPEC-J2 was observed and confirmed by microarray data. Measurements of oxygen consumption resulted in a significant reduction, if DON attacks from the basolateral. Furthermore, we found a dose-dependent effect with a significant reduction at 2000 ng/mL. In addition, SLC7A11 and PHB, the genes with the highest regulation in our microarray analyses under low glucose supply, were investigated and showed a variable regulation on protein level. Lactate production and glucose consumption was investigated to examine the impact of DON on anaerobic glycolysis and we observed a significant increase in 2000 bl^high and a decrease in 2000 ap^high. Interestingly, both groups as well as 200 bl^high showed a significant higher de novo protein synthesis when compared to the control. These results indicate the direct or indirect impact of DON on metabolic pathways in IPEC-J2.

The role of miR-122 in the dysregulation of glucose-6-phosphate dehydrogenase (G6PD) expression in hepatocellular cancer

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. Thus, a better understanding of molecular aberrations involved in HCC pathogenesis is necessary for developing effective therapy. It is well established that cancer cells metabolize energy sources differently to rapidly generate biomass. Glucose-6-phosphate-dehydrogenase (G6PD), the rate-limiting enzyme of the Pentose Phosphate Pathway (PPP), is often activated in human malignancies to generate precursors for nucleotide and lipid synthesis. Here, we determined the clinical significance of G6PD in primary human HCC by analyzing RNA-seq and clinical data in The Cancer Genome Atlas. We found that the upregulation of G6PD correlates with higher tumor grade, increased tumor recurrence, and poor patient survival. Notably, liver-specific miR-122, which is essential for metabolic homeostasis, suppresses G6PD expression by directly interacting with its 3'UTR. Luciferase reporter assay confirmed two conserved functional miR-122 binding sites located in the 3'-UTR of G6PD. Furthermore, we show that ectopic expression of miR-122 and miR-1, a known regulator of G6PD expression coordinately repress G6PD expression in HCC cells. These miRNAs also reduced G6PD activity in HepG2 cells that express relatively high activity of this enzyme. Collectively, this study provides evidence that anti-HCC efficacy of miR122 and miR-1 could be mediated, at least in part, through inhibition of PPP by suppressing the expression of G6PD.

CD44 positive and sorafenib insensitive hepatocellular carcinomas respond to the ATP-competitive mTOR inhibitor INK128

The mTOR pathway is activated in about 50% of patients with hepatocellular carcinoma (HCC). In an effort to identify new pathways and compounds to treat advanced HCC, we considered the ATP-competitive mTOR inhibitor INK128. ATP-competitive mTOR inhibitors attenuate both mTORC1 and mTORC2. INK128 was evaluated in sorafenib sensitive and insensitive HCC cell lines, CD44low and CD44high HCC and those cell lines with acquired sorafenib resistance. CD44 was significantly increased in Huh7 cells made resistant to sorafenib. Forced expression of CD44 enhanced cellular proliferation and migration, and rendered the cells more sensitive to the anti-proliferative effects of INK128. INK128 suppressed CD44 expression in HCC cells while allosteric mTOR inhibitors did not. CD44 inhibition correlated with 4EBP1 phosphorylation status. INK128 showed better anti-proliferative and anti-migration effects on the mesenchymal-like HCC cells, CD44high HCC cells compared to the allosteric mTOR inhibitor everolimus. Moreover, a combination of INK128 and sorafenib showed improved anti-proliferative effects in CD44high HCC cells. INK128 was efficacious at reducing tumor growth in CD44high SK-Hep1 xenografts in mice when given as monotherapy or in combination with sorafenib. Since the clinical response to sorafenib is highly variable, our findings suggest that ATP-competitive mTOR inhibitors may be effective in treating advanced, CD44-expressing HCC patients who are insensitive to sorafenib.

Nutritional shortage augments cisplatin-effects on murine melanoma cells

Melanoma incidence increases every year worldwide and is responsible for 80% of skin cancer deaths. Due to its metastatic potential and resistance to almost any treatments such as chemo, radio, immune and targeted-therapy, the patients still have a poor prognosis, especially at metastatic stage. Considering that, it is crucial to find new therapeutic approaches to overcome melanoma resistance. Here we investigated the effect of cisplatin (CDDP), one of the chemotherapeutic agents used for melanoma treatment, in association with nutritional deprivation in murine melanoma cell lines. Cell death and autophagy were evaluated after the treatment with cisplatin, nutritional deprivation and its association using an in vitro model of murine melanocytes malignant transformation to metastatic melanoma. Our results showed that nutritional deprivation augmented cell death induced by cisplatin in melanoma cells, especially at the metastatic subtype, with slight effects on melanocytes. Mechanistic studies revealed that although autophagy was present at high levels in basal conditions in melanoma cells, was not essential for cell death process that involved mitochondrial damage, reactive oxygen species production and possible glycolysis inhibition. In conclusion, nutritional shortage in combination with chemotherapeutic drugs as cisplatin can be a valuable new therapeutic strategy to overcome melanoma resistance.

Reprograming of Glucose Metabolism by Zerumbone Suppresses Hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the most prevalent and highly aggressive liver malignancy with limited therapeutic options. Here, the therapeutic potential of zerumbone, a sesquiterpene derived from the ginger plant Zingiber zerumbet, against HCC was explored. Zerumbone inhibited proliferation and clonogenic survival of HCC cells in a dose-dependent manner by arresting cells at the G₂-M phase and inducing apoptosis. To elucidate the underlying molecular mechanisms, a phosphokinase array was performed that showed significant inhibition of the PI3K/AKT/mTOR and STAT3 signaling pathways in zerumbone-treated HCC cells. Gene expression profiling using microarray and analysis of microarray data by Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) revealed that zerumbone treatment resulted in significant deregulation of genes regulating apoptosis, cell cycle, and metabolism. Indeed, tracing glucose metabolic pathways by growing HCC cells with ¹³C₆-glucose and measuring extracellular and intracellular metabolites by 2D nuclear magnetic resonance (NMR) spectroscopy showed a reduction in glucose consumption and reduced lactate production, suggesting glycolytic inhibition. In addition, zerumbone impeded shunting of glucose-6-phosphate through the pentose phosphate pathway, thereby forcing tumor cells to undergo cell-cycle arrest and apoptosis. Importantly, zerumbone treatment suppressed subcutaneous and orthotopic growth and lung metastasis of HCC xenografts in immunocompromised mice. In conclusion, these findings reveal a novel and potentially effective therapeutic strategy for HCC using a natural product that targets cancer cell metabolism.Implications: Dietary compounds, like zerumbone, that impact cell cycle, apoptosis, and metabolic processes may have therapeutic benefits for HCC patients. Mol Cancer Res; 16(2); 256-68. ©2017 AACR.

Combined Inhibitions of Glycolysis and AKT/autophagy Can Overcome Resistance to EGFR-targeted Therapy of Lung Cancer

Efficacy of EGFR-targeted tyrosine kinase inhibitors (TKIs), such as erlotinib, to treat human non-small cell lung cancers (NSCLCs) with activating mutations in EGFR is not persistent due to drug resistance. Reprogramming in energy (especially glucose) metabolism plays an important role in development and progression of acquired resistance in cancer cells. We hypothesize that glucose metabolism in EGFR-TKI sensitive HCC827 cells and erlotinib-resistant sub-line of HCC827 (which we name it as erlotinib-resistant 6, ER6 cells in this study) is different and targeting glucose metabolism might be a treatment strategy for erlotinib-resistant NSCLCs. In this study, we found increased glucose uptakes, significant increase in glycolysis rate and overexpression of glucose transporter 1 in ER6 cells compared to its parental cells HCC827. We also found AKT and autophagy of ER6 cells were more activated than HCC827 cells after glucose starvation. Combining glucose deprivation and AKT or autophagy inhibitor could synergize and overcome the acquired resistance against EGFR-targeted therapy for NSCLCs. Our data suggest that the combinations of inhibitors of AKT or autophagy together with glucose deprivation could be novel treatment strategies for NSCLC with acquired resistance to targeted therapy.

Chemotherapy for hepatocellular carcinoma: The present and the future

Hepatocellular carcinoma (HCC) is the most common primary tumor of the liver. Its relationship to chronic liver diseases, in particular cirrhosis, develops on a background of viral hepatitis, excessive alcohol intake or metabolic steatohepatitis, leads to a high incidence and prevalence of this neoplasia worldwide. Despite the spread of HCC, its treatment it’s still a hard challenge, due to high rate of late diagnosis and to lack of therapeutic options for advanced disease. In fact radical surgery and liver transplantation, the most radical therapeutic approaches, are indicated only in case of early diagnosis. Even local therapies, such as transarterial chemoembolization, find limited indications, leading to an important problem regarding treatment of advanced disease. In this situation, until terminal HCC occurs, systemic therapy is the only possible approach, with sorafenib as the only standard treatment available. Anyway, the efficacy of this drug is limited and many efforts are necessary to understand who could benefit more with this treatment. Therefore, other molecules for a targeted therapy were evaluated, but only regorafenib showed promising results. Beside molecular target therapy, also cytotoxic drugs, in particular oxaliplatin- and gemcitabine-based regimens, and immune-checkpoint inhibitors were tested with interesting results. The future of the treatment of this neoplasia is linked to our ability to understand its mechanisms of resistance and to find novel therapeutic targets, with the objective to purpose individualized approaches to patients affected by advanced HCC.