The action and resistance mechanisms of Lenvatinib in liver cancer

Targeted inhibition of PDGFRA with avapritinib, markedly enhances lenvatinib efficacy in hepatocellular carcinoma in vitro and in vivo: clinical implications

BACKGROUND

Lenvatinib, a tyrosine kinase receptor inhibitor, has emerged as a frontline therapeutic strategy for the management of advanced hepatocellular carcinoma (HCC). However, the modest response rate observed with lenvatinib and the rapid emergence of chemoresistance highlight the urgent need to elucidate the underlying molecular mechanisms. Herein we aimed at identifying the molecular mechanisms underlying lenvatinib resistance in HCC and investigated the efficacy of targeted combination therapies to surmount this chemoresistance.

METHODS

We utilized CRISPR/Cas9 gene knockout screening combined with transcriptome sequencing of lenvatinib-resistant HCC cell lines to identify resistance-associated genes. PDGFRA overexpression was validated in human lenvatinib-resistant HCC cells. We further corroborated the in vitro and in vivo role of PDGFRA in lenvatinib resistance using a PDGFRA inhibitor, avapritinib, employing a mouse orthotopic HCC model, patient-derived organoids (PDO), and patient-derived xenografts (PDX). The association between PDGFRA expression and patient prognosis was also assessed. Mechanistic studies were conducted to elucidate the signaling pathways contributing to lenvatinib resistance mediated by PDGFRA.

RESULTS

PDGFRA overexpression was identified as a key determinant of lenvatinib-resistance in HCC cells. Consistently, ectopic PGDGFRA overexpression conferred lenvatinib resistance upon HCC cells. Treatment with the PDGFRA inhibitor avapritinib sensitized HCC cells to lenvatinib in mouse orthotopic HCC, PDO, and PDX models. Increased PDGFRA expression was correlated with poor prognosis in HCC patients. Mechanistic studies revealed that lenvatinib treatment or PDGFRA overexpression promoted HCC resistance through the PTEN/AKT/GSK-3β/β-catenin signaling pathway.

CONCLUSIONS

Our findings demonstrate that PDGFRA overexpression mediates lenvatinib resistance in HCC and that targeting PDGFRA with avapritinib, surmounts this resistance. Furthermore, the PTEN/AKT/GSK-3β/β-catenin pathway was implicated in lenvatinib resistance, providing a potential therapeutic strategy for HCC patients displaying lenvatinib resistance. Further clinical studies are warranted to validate these findings and to explore the clinical application of PDGFRA-targeted therapies in HCC treatment.

Endometrial cancer: Part II. Multimodality treatment of uterine high-grade serous carcinoma (clinical course II)

The part II (clinical course I) of endometrial cancer (EC) describing the complex clinical course (initial treatment and therapy for the first recurrence at both local-regional and distant metastatic sites) of a 66-year-old woman with uterine high-grade serous carcinoma (HGSC, post-curettage diagnosis) after minimally invasive surgery (MIS) treatment-confirmed absence of residual tumor. In the clinical course I, we discussed the recent trend in using MIS for treating early-stage EC patients, regardless whether histologic types are classified, as well as the rationale of absent following postoperative adjuvant therapy due to no residual tumor of gross specimen after complete staging surgery. The patient had multiple recurrences at both loco-regional and distant sites after 22-month disease-free survival (DFS). After salvage therapy, including incomplete cytoreductive surgery for symptom control, chemotherapy, radiotherapy and final systemic therapy, the patient had a durable response period (10-month treatment plus 9 months of the 2nd progression-free survival [PFS]). The current report is the subsequent clinical course of this patient (clinical course II), which further managed this patient at the second recurrence based on multiple modality treatment to achieve the durable response and significantly improve the quality of life.

Biomimetic Co-delivery of Lenvatinib and FePt Nanoparticles for Enhanced Ferroptosis/Apoptosis Treatment of Hepatocellular Carcinoma

Lenvatinib, endorse as a first-line targeted therapy, has demonstrated efficacy in extending the survival span of individuals afflicted with advanced Hepatocellular carcinoma (HCC). However, its therapeutic effect wears off with time, which is ascribed to the cancer cell's tendency to evade and tamper with its usual modes of action, severely limiting its clinical use. This study devises an innovative therapeutic modality involving the synergistic co-delivery of FePt nanoparticles (NPs) and Lenvatinib via poly lactic-co-glycolic acid (PLGA) NPs encase in HCC cell membranes (Len/FePt@CMP NPs). The investigation explores the mechanism through which Lenvatinib induces ferroptosis in HCC, notably by dampening the glutathione peroxidase 4 (GPX4) through the inhibition of fibroblast growth factor receptor 4. FePt NPs are engineered to enhance the efficacy of ferroptosis and apoptosis for HCC treatment. Concurrently, the incorporation of the cancer cell membrane facilitates the targeted accumulation of NPs at the tumor site, leveraging mechanisms of immune evasion and homologous targeting. This enhances ferroptosis/apoptosis treatment efficacy, triggeres by Len/FePt@CMP NPs, is convincingly demonstrated both in vitro and in vivo. The proposed approach has the potential to redefine HCC therapeutic paradigms by overcoming mono-therapeutic limitations in current clinical treatments, showcasing the improved efficacy of a comprehensive strategy.

Protocadherin 17 weakens the lenvatinib resistance of liver cancer through inducing ferroptosis

Lenvatinib has been employed in the treatment of advanced liver cancer; however, its clinical application is significantly impeded by frequent drug resistance. Recent studies have revealed that lenvatinib treatment triggers ferroptosis in liver cancer cells, providing a novel approach to addressing lenvatinib resistance. In this study, we initially validated the induction of ferroptosis by lenvatinib in liver cancer cells. Remarkably, protocadherin 17 (PCDH17), an adhesion-related protein, was found to be down-regulated in liver cancer, and overexpression of PCDH17 could induce ferroptosis in liver cancer cells. Importantly, silencing PCDH17 inhibited the impact of lenvatinib on liver cancer cell ferroptosis, while overexpression of PCDH17 had the opposite effect. These findings were further confirmed using a xenograft tumor model in BALB/c nude mice. Additionally, lenvatinib-resistant (LR) liver cancer cells were generated for additional validation purposes. It was observed that LR-liver cancer cells lost their susceptibility to ferroptosis induction by lenvatinib; however, overexpression of PCDH17 reactivated their sensitivity to ferroptosis. Corresponding results were also verified in BALB/c nude mice models. In conclusion, these results suggest that as a novel regulator of ferroptosis, PCDH17 can alleviate lenvatinib resistance and potentially enhance the therapeutic efficacy of lenvatinib in treating liver cancer.

SOX11 exacerbates ferroptosis to reduce lenvatinib resistance in liver cancer cells by promoting ubiquitination degradation of SREBF1 through upregulating UBE3A

Lenvatinib is one of the most commonly used first-line drugs for liver cancer. However, lenvatinib resistance occurs in a large proportion of patients, posing a significant challenge. Ferroptosis, an iron-dependent form of cell death, plays a pivotal role in overcoming drug resistance. This study investigates the role of SRY-related HMG-box transcription factor 11 (SOX11) in regulating lenvatinib resistance in liver cancer through its impact on ferroptosis. qRT-PCR, western blot, and immunohistochemistry were performed to examine the expression of key molecules in patient samples and cell lines. Functional studies, including cell viability and proliferation assays, colony formation assays, flow cytometry, and measurements of iron metabolism markers, were conducted to explore the biological effects of these molecules. Additionally, Co-IP, ChIP, dual-luciferase reporter assays, and in vivo tumorigenesis experiments were performed to uncover the underlying regulatory mechanisms. Our results showed that UBE3A was markedly downregulated in lenvatinib-resistant liver cancer tissues and cells, and its overexpression markedly reduced lenvatinib resistance in liver cancer cells by promoting ferroptosis. Mechanically, UBE3A reduced lenvatinib resistance in lenvatinib-resistant liver cancer cells by mediating ubiquitination-independent degradation of SREBF1. In addition, SOX11 upregulation reduced lenvatinib resistance in liver cancer cells by promoting ferroptosis through transcriptionally activated UBE3A expression. In summary, SOX11 upregulation promoted ferroptosis in liver cancer cells by promoting SREBF1 ubiquitination degradation through transcriptionally elevating UBE3A expression, thereby sensitizing lenvatinib-resistant liver cancer cells to lenvatinib.

Roles of PDGF/PDGFR signaling in various organs

Platelet-derived growth factors (PDGFs) ligands and their corresponding receptors, PDGF receptor (PDGFR)α and PDGFRβ, play a crucial role in controlling diverse biological functions, including cell growth, viability and migration. These growth factors bind to PDGFRs, which are receptor tyrosine kinases present on the surface of target cells. The interaction between PDGFs and PDGFRs induces receptor dimerization and subsequent activation through auto-phosphorylation, which in turn triggers a cascade of intracellular signaling pathways. PDGF/PDGFR signaling is essential for maintaining normal physiological functions, including tissue regeneration and growth. However, dysregulation of this signaling pathway leads to pathological conditions, including fibrosis, atherosclerosis, and cancer development in various organs. The pathological impact of PDGF/PDGFR signaling primarily stems from its capacity to promote excessive cell proliferation, enhanced migration, and increased extracellular matrix deposition, resulting in tissue overgrowth, scarring, and abnormal vessel formation. These processes are integral to the pathogenesis of fibrotic, neoplastic, and vascular disorders. Therefore, understanding these pathways is crucial for developing targeted treatments designed to inhibit PDGF/PDGFR signaling in these diseases. This review delves into the dual role of PDGF/PDGFR signaling in both physiological and pathophysiological contexts across different organs and provides insights into current pharmacological therapies designed to target the PDGF signaling pathway.

Mesenchymal Stem Cell-Derived Exosomes in Cancer Resistance Against Therapeutics

Mesenchymal stem cells (MSCs) are specialized cells that can differentiate into various types of cells. MSCs can be utilized to treat cancer. However, a MSC is considered a double-edged sword, because it can promote tumor progression and support cancer cell growth. Likewise, MSC-derived exosomes (MSC-Exos) carry various intracellular materials and transfer them to other cells. MSC-Exos could also cause tumor progression, including brain cancer, breast cancer, hepatic cancer, lung cancer, and colorectal cancer, and develop resistance against therapies, mainly chemotherapy, radiotherapy, and immunotherapy. An MSC-Exo promotes tumor development and causes drug resistance in various cancer types. The mechanisms involved in cancer drug resistance vary depending on the cancer cell heterogeneity and complexity. In this article, we have explained the various biomarkers and mechanisms involved in the tumor and resistance development through MSC-Exos in different cancer types.

Protein Coronation-Induced Cancer Staging-Dependent Multilevel Cytotoxicity: An All-Humanized Study in Blood Vessel Organoids

The protein corona effect refers to the phenomenon wherein nanomaterials in the bloodstream are coated by serum proteins, yet how protein coronated nanomaterials interact with blood vessels and its toxicity implications remain poorly understood. In this study, we investigated protein corona-related vessel toxicity by using an all-humanized assay integrating blood vessel organoids and patient-derived serum. Initially, we screened various nanomaterials to discern how parameters including size, morphology, hydrophobicity, surface charge, and chirality-dependent protein corona difference influence their uptake by vessel organoids. For nanomaterials showing substantial differences in vessel uptake, their protein corona was analyzed by using label-free mass spectra. Our findings revealed the involvement of cancer staging-related cytoskeleton components in mediating preferential uptake by cells, including endothelial and mural cells. Additionally, a transcriptome study was conducted to elucidate the influence of nanomaterials. We confirmed that protein coronated nanomaterials provoke remodeling at both transcriptional and translational levels, impacting pathways such as PI3K-Akt/Hippo/Wnt, and membraneless organelle integrity, respectively. Our study further demonstrated that the remodeling potential of patient-derived protein coronated nanomaterials can be harnessed to synergize with antiangiogenesis therapeutics to improve the outcomes. We anticipate that this study will provide guidance for the safe use of nanomedicine in the future.

Tyrosine Kinase Inhibitor Lenvatinib Causes Cardiotoxicity by Inducing Endoplasmic Reticulum Stress and Apoptosis through Activating ATF6, IRE1α and PERK Signaling Pathways

BACKGROUND

Lenvatinib is a tyrosine kinase inhibitor that can improve progression-free survival in patients with thyroid cancer and hepatocellular carcinoma. However, it is limited by adverse cardiovascular events, including hypertension and cardiac dysfunction. Activation of endoplasmic reticulum stress is involved in cardiomyocyte apoptosis.

OBJECTIVE

This study aimed to confirm whether the cardiotoxicity of lenvatinib is associated with endoplasmic reticulum stress by targeting the activating transcription factor 6 (ATF6), inositol- requiring enzyme 1α (IRE1α) and protein kinase RNA-like ER kinase (PERK) signaling pathways.

METHODS

Male C57/BL6 mice were intragastric administration with 30 mg/kg/day lenvatinib. Electrocardiography (ECG) and echocardiography were used to detect arrhythmias and cardiac function. Neonatal rat cardiomyocytes were treated with lenvatinib for 48h. Cell counting kit (CCK8), 2´,7´-dichlorodihydrofluoresceine diacetate (H2DCFHDA), Hoechst 33258 and dihydrorhodamine 123 were respectively used for evaluating cell viability, the level of reactive oxygen species (ROS), nuclear morphological changes and mitochondrial membrane potential (MMP) level.

RESULTS

Lenvatinib remarkably decreased the posterior wall thickness of left ventricle during diastole and systole but caused little decrease to the left ventricular ejection fraction (LVEF, %). Furthermore, lenvatinib greatly prolonged the corrected QT interval (QTc) and altered the morphology of cardiomyocytes. No significant difference in fibrosis was found in mouse cardiac slices. Lenvatinib upregulates apoptosis-related protein expression. In addition, lenvatinib increased ERS-related proteins expression (GRP78, CHOP, and ATF6) and enhanced PERK phosphorylation. In neonatal rat cardiac myocytes, lenvatinib markedly decreased the viability of cardiomyocytes and induced apoptosis. Furthermore, ROS production increased and MMP decreased. Similar to the mice experiment, lenvatinib caused upregulation of apoptosis-related and ERS-related proteins and increased the phosphorylation levels of PERK and IRE1α.

CONCLUSION

Lenvatinib-induced cardiotoxicity is associated with ERS-induced apoptosis by targeting the ATF6, IRE1α, and PERK signaling pathways.

Lenvatinib and immune-checkpoint inhibitors in hepatocellular carcinoma: mechanistic insights, clinical efficacy, and future perspectives

Lenvatinib is a multi-target tyrosine kinase inhibitor widely used in the treatment of hepatocellular carcinoma (HCC). Its primary mechanism of action involves inhibiting signal pathways such as vascular endothelial growth factor receptors (VEGFR) and fibroblast growth factor receptors (FGFR), thereby reducing tumor cell proliferation and angiogenesis and affecting the tumor's immune microenvironment. In the treatment of liver cancer, although lenvatinib monotherapy has shown good clinical effect, the problem of drug resistance is becoming more and more serious. This resistance may be caused by a variety of factors, including genetic mutations, signaling pathway remodeling, and changes in the tumor microenvironment. In order to overcome drug resistance, the combination of lenvatinib and other therapeutic strategies has gradually become a research hotspot, and it is worth noting that the combination of lenvatinib and immune checkpoint inhibitors (ICIs) has shown a good application prospect. This combination not only enhances the anti-tumor immune response but also helps improve therapeutic efficacy. However, combination therapy also faces challenges regarding safety and tolerability. Therefore, studying the mechanisms of resistance and identifying relevant biomarkers is particularly important, as it aids in early diagnosis and personalized treatment. This article reviews the mechanisms of lenvatinib in treating liver cancer, the mechanisms and efficacy of its combination with immune checkpoint inhibitors, the causes of resistance, the exploration of biomarkers, and other novel combination therapy strategies for lenvatinib. We hope to provide insights into the use and research of lenvatinib in clinical and scientific settings, offering new strategies for the treatment of liver cancer.

A Novel Glycoengineered Humanized Antibody Targeting DLK1 Exhibits Potent Anti-Tumor Activity in DLK1-Expressing Liver Cancer Cell Xenograft Models

Delta-like 1 homolog (DLK1), a non-canonical Notch ligand, is highly expressed in various malignant tumors, especially in hepatocellular carcinoma (HCC). CBA-1205 is an afucosylated humanized antibody against DLK1 with enhanced antibody-dependent cellular cytotoxicity (ADCC). The binding characteristics of CBA-1205 were analyzed by enzyme-linked immunosorbent assay and fluorescence-activated cell sorting assay. The ADCC activity of CBA-1205 was assessed. The anti-tumor efficacy of CBA-1205 was evaluated in xenograft mouse models, and toxicity and toxicokinetic profiles of CBA-1205 were evaluated in cynomolgus monkeys. CBA-1205 selectively bound to DLK1 among the Notch ligands and only to monkey and human DLK1. The binding epitope was between epidermal growth factor-like domains 1 and 2 of DLK1, which are not involved in any known physiological functions. The ADCC activity of CBA-1205 was confirmed using human peripheral blood mononuclear cells as effector cells. CBA-1205 as a single agent and in combination with lenvatinib demonstrated long-lasting anti-tumor efficacy, including tumor regression, in two liver cancer xenograft models. The toxicity and toxicokinetic profiles of CBA-1205 in cynomolgus monkeys were favorable. These findings suggest that CBA-1205 has the potential to be a useful therapeutic option for drug treatment in HCC. A phase 1 study is ongoing in patients with advanced cancers (jRCT2080225288, NCT06636435).

Notch signaling in digestive system cancers: Roles and therapeutic prospects

Digestive system cancers rank among the most prevalent malignant tumors, maintaining persistently high incidence and mortality rates. Notch signaling activity, often aberrant in esophageal, gastric, hepatic, pancreatic, and colorectal cancers, plays a pivotal role in the initiation, progression, and therapy resistance of these malignancies. As a highly conserved pathway, Notch signaling is integral to cell differentiation, survival, proliferation, stem cell renewal, development, and morphogenesis. Its dysregulation has been increasingly linked to various diseases, particularly digestive system cancers. In these malignancies, altered Notch signaling influences multiple biological processes, including cell proliferation, invasion, cell cycle progression, immune evasion, drug resistance, and stemness maintenance. Understanding the mechanisms of Notch signaling in digestive system cancers is essential for the development of novel targeted therapies. Numerous Notch pathway-targeting drugs are currently in preclinical studies, demonstrating promising efficacy both as monotherapies and in combination with conventional anti-cancer treatments. This review summarizes recent high-quality findings on the involvement of Notch signaling in digestive system cancers, focusing on the expression changes and pathological mechanisms of its dysregulated components. Special emphasis is placed on the potential of translating Notch-targeted approaches into therapeutic strategies, which hold promise for overcoming the limitations of existing treatments and improving the poor prognosis associated with these cancers.

Hepatitis B Virus-Induced Resistance to Sorafenib and Lenvatinib in Hepatocellular Carcinoma Cells: Implications for Cell Viability and Signaling Pathways

Background/Objectives: Sorafenib and lenvatinib are tyrosine kinase inhibitors used in hepatocellular carcinoma (HCC) treatment. This study investigates how hepatitis B virus (HBV) infection affects their efficacy in HepG2 hepatoma cells. Methods: HepG2 and HBV-infected HepG2/2215 cells were treated with varying concentrations of both drugs. The cell viability, cell cycle gene expression, cycle progression, and phosphorylation levels of ERK and AKT were analyzed. Results: The HBV-infected cells showed significant alterations in their cell cycle gene expressions, with an 80-fold increase in CCND2 expression and a higher proportion of cells in the G2/M phase, indicating enhanced proliferation. While both drugs decreased HepG2 cell viability in a concentration-dependent manner, HBV infection conferred resistance, as evidenced by the increased viable cells in the HepG2/2215 cultures. Sorafenib and lenvatinib decreased key cyclin and cyclin-dependent kinase expressions in uninfected cells, with less effect on the HBV-infected cells. Both drugs lowered the pERK and pAKT levels in the HepG2 cells. In the HBV-infected cells, sorafenib reduced the pERK and pAKT levels to a lesser extent. However, treatment with lenvatinib elevated the levels of pERK and pAKT. Conclusions: In conclusion, HBV infection increases resistance to both sorafenib and lenvatinib in hepatoma cells by influencing the cell cycle regulatory genes and critical signaling pathways. However, the resistance mechanisms likely differ between the two medications.

Effects of three flavonoids on the metabolism of lenvatinib

Lenvatinib is a first-line therapy for the treatment of hepatocellular carcinoma (HCC), an active multi-target tyrosine kinase inhibitor (TKI). The interaction between Traditional Chinese Medicine (TCM) and chemicals has increasingly become a research hotspot. The objective of this study was to pinpoint the effects of three flavonoids on the metabolism of lenvatinib. Enzyme reaction system was established and optimized in vitro, and in vivo experiments were conducted in Sprague-Dawley (SD) rats, where the analytes were detected by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). We found that among three flavonoids, luteolin and myricetin had strong inhibitory effects on lenvatinib metabolism, with half-maximal inhibitory concentration (IC50) values of 11.36 ± 0.46 µM and 11.21 ± 0.81 µM in rat liver microsomes (RLM), respectively, and 6.89 ± 0.43 µM and 12.32 ± 1.21 µM in human liver microsomes (HLM), respectively. In Sprague-Dawley rats, the combined administration of lenvatinib and luteolin obviously expanded the exposure to lenvatinib; however, co-administered with myricetin did not have any changes, which may be due to the poor bioavailability of myricetin in vivo. Furthermore, the inhibitory type of luteolin on lenvatinib showed an un-competitive in RLM and a mixed in HLM. Collectively, flavonoids with liver protection, especially luteolin, may inhibit lenvatinib metabolism in vitro and in vivo.

EVA1A reverses lenvatinib resistance in hepatocellular carcinoma through regulating PI3K/AKT/p53 signaling axis

Lenvatinib is a commonly used first-line drug for the treatment of advanced hepatocellular carcinoma (HCC). However, its clinical efficacy is limited due to the drug resistance. EVA1A was a newly identified tumor suppressor, nevertheless, the impact of EVA1A on resistance to lenvatinib treatment in HCC and the potential molecular mechanisms remain unknown. In this study, the expression of EVA1A in HCC lenvatinib-resistant cells is decreased and its low expression was associated with a poor prognosis of HCC. Overexpression of EVA1A reversed lenvatinib resistance in vitro and in vivo, as demonstrated by its ability to promote cell apoptosis and inhibit cell proliferation, invasion, migration, EMT, and tumor growth. Silencing EVA1A in lenvatinib-sensitive parental HCC cells exerted the opposite effect and induced resistance to lenvatinib. Mechanistically, upregulated EVA1A inhibited the PI3K/AKT/MDM2 signaling pathway, resulting in a reduced interaction between MDM2 and p53, thereby stabilizing p53 and enhancing its antitumor activity. In addition, upregulated EVA1A suppressed the PI3K/AKT/mTOR signaling pathway and promoted autophagy, leading to the degradation of mutant p53 and attenuating its oncogenic impact. On the contrary, loss of EVA1A activated the PI3K/AKT/MDM2 signaling pathway and inhibited autophagy, promoting p53 proteasomal degradation and mutant p53 accumulation respectively. These findings establish a crucial role of EVA1A loss in driving lenvatinib resistance involving a mechanism of modulating PI3K/AKT/p53 signaling axis and suggest that upregulating EVA1A is a promising therapeutic strategy for alleviating resistance to lenvatinib, thereby improving the efficacy of HCC treatment.

SMARCD3 Overexpression Promotes Epithelial-Mesenchymal Transition in Gastric Cancer

This study investigates the role of SMARCD3 in gastric cancer by comparing its expression in signet ring cell (SRC) and well-differentiated (WD) groups within gastric cancer cell lines and tissues. We observed elevated SMARCD3 levels in the SRC group compared to the WD group. Functional analysis was conducted through both SMARCD3 knock-in and knock-out methods. Kaplan-Meier survival analysis indicated that higher SMARCD3 expression correlates with poorer overall survival in gastric cancer patients (HR 2.16, p < 0.001). SMARCD3 knock-out cells showed decreased proliferation, migration, invasion, and expression of epithelial-mesenchymal transition (EMT) markers, contrasting with results from temporary and stable SMARCD3 overexpression experiments, which demonstrated increased cell area and irregularity (p < 0.001). Further analysis revealed that SMARCD3 overexpression in MKN-74 cells significantly enhanced p-AKT-S473 and p-ERK levels (p < 0.05), and in KATO III cells, it increased β-catenin and PI3Kp85 activities (p < 0.05). Conversely, these activities decreased in SNU 601 cells following SMARCD3 depletion. The study concludes that SMARCD3 overexpression may serve as a negative prognostic marker and a potential therapeutic target in gastric cancer treatment due to its role in promoting EMT.

Liver cancer wars: plant-derived polyphenols strike back

Liver cancer currently represents the leading cause of cancer-related death worldwide. The majority of liver cancer arises in the context of chronic inflammation and cirrhosis. Surgery, radiation therapy, and chemotherapy have been the guideline-recommended treatment options for decades. Despite enormous advances in the field of liver cancer therapy, an effective cure is yet to be found. Plant-derived polyphenols constitute a large family of phytochemicals, with pleiotropic effects and little toxicity. They can drive cellular events and modify multiple signaling pathways which involves initiation, progression and metastasis of liver cancer and play an important role in contributing to anti-liver cancer drug development. The potential of plant-derived polyphenols for treating liver cancer has gained attention from research clinicians and pharmaceutical scientists worldwide in the last decades. This review overviews hepatic carcinogenesis and briefly discusses anti-liver cancer mechanisms associated with plant-derived polyphenols, specifically involving cell proliferation, apoptosis, autophagy, angiogenesis, oxidative stress, inflammation, and metastasis. We focus on plant-derived polyphenols with experiment-based chemopreventive and chemotherapeutic properties against liver cancer and generalize their basic molecular mechanisms of action. We also discuss potential opportunities and challenges in translating plant-derived polyphenols from preclinical success into clinical applications.

Chloroquine and Chemotherapeutic Compounds in Experimental Cancer Treatment

Chloroquine (CQ) and its derivate hydroxychloroquine (HCQ), the compounds with recognized ability to suppress autophagy, have been tested in experimental works and in clinical trials as adjuvant therapy for the treatment of tumors of different origin to increase the efficacy of cytotoxic agents. Such a strategy can be effective in overcoming the resistance of cancer cells to standard chemotherapy or anti-angiogenic therapy. This review presents the results of the combined application of CQ/HCQ with conventional chemotherapy drugs (doxorubicin, paclitaxel, platinum-based compounds, gemcitabine, tyrosine kinases and PI3K/Akt/mTOR inhibitors, and other agents) for the treatment of different malignancies obtained in experiments on cultured cancer cells, animal xenografts models, and in a few clinical trials. The effects of such an approach on the viability of cancer cells or tumor growth, as well as autophagy-dependent and -independent molecular mechanisms underlying cellular responses of cancer cells to CQ/HCQ, are summarized. Although the majority of experimental in vitro and in vivo studies have shown that CQ/HCQ can effectively sensitize cancer cells to cytotoxic agents and increase the potential of chemotherapy, the results of clinical trials are often inconsistent. Nevertheless, the pharmacological suppression of autophagy remains a promising tool for increasing the efficacy of standard chemotherapy, and the development of more specific inhibitors is required.