Sorcin promotes proliferation of hepatocellular carcinoma by regulating VEGFA/B via PI3K pathway.

Hepatocellular carcinoma (HCC) is a highly vascularized tumor, one of the most common and lethal cancer-related tumor deaths worldwide, with cell proliferation playing a key role. In this study our western blot results and data from TAGC demonstrate a strong association between Sorcin (SRI) overexpression and poor outcomes in HCC. Moreover, SRI overexpression was remarkably effective in promoting proliferation in vitro and increasing tumor growth in vivo, which were attenuated by knocking down SRI. Mechanistically, SRI regulated vascular endothelial growth factor A (VEGFA) and vascular endothelial growth factor B (VEGFB) through PI3K/Akt/FOXO1 signal pathway. Overall, our study indicates that SRI stimulates HCC growth by controlling VEGFA/B, which presents a fresh insight into the pathogenesis of hepatocarcinogenesis and a new therapeutic target for HCC.

SCD1 inhibits HBV replication by regulating autophagy under high lipid conditions.

Chronic hepatitis B virus (HBV) infection remains a significant public health concern worldwide. Several metabolic processes regulate HBV DNA replication, including autophagy and lipid metabolism. In this study, we clarified the effect of lipids on HBV replication and elucidated possible mechanisms. We discovered that lipid metabolic gene expression levels were negatively correlated with the HBV DNA in plasma. Our data showed that fatty acid stimulation significantly reduced HBV DNA, hepatitis B surface antigen (HBsAg), and hepatitis B e antigen (HBeAg) levels in HepG2.2.15 cells, which are human hepatoma cell cultures transfected with HBV DNA. The Stearoyl coenzyme A desaturase 1 (SCD1)-autophagy pathway has also been implicated in inhibiting HBV replication by fatty acids stimulation. SCD1 knockdown deregulates the inhibitory effect of fatty acids on HBV by enhancing autophagy. When 3 methyladenine (3MA) was added, the inhibitory effects of specific autophagy inhibitors eliminated the positive effects of SCD1 knockdown on HBV replication. Our results indicate that SCD1 participates in the regulation of inhibition of HBV replication by fatty acids stimulation through regulating autophagy.

Development and validation of a machine learning-based model for varices screening in compensated cirrhosis (CHESS2001): an international multicenter study.

BACKGROUND AND AIMS: The prevalence of high-risk varices (HRV) is low among compensated cirrhotic patients undergoing EGD. Our study aimed to identify a novel machine learning (ML)-based model, named ML EGD, for ruling out HRV and avoiding unnecessary EGDs in patients with compensated cirrhosis. METHODS: An international cohort from 17 institutions from China, Singapore, and India were enrolled (CHESS2001). The variables with the top 3 importance scores (liver stiffness, platelet count, and total bilirubin) were selected by the Shapley additive explanation and input into a light gradient-boosting machine algorithm to develop ML EGD for identification of HRV. Furthermore, we built a web-based calculator for ML EGD, which is free with open access (http://www.pan-chess.cn/calculator/MLEGD_score). Unnecessary EGDs that were not performed and the rates of missed HRV were used to assess the efficacy and safety for varices screening. RESULTS: Of 2794 enrolled patients, 1283 patients formed a real-world cohort from 1 university hospital in China used to develop and internally validate the performance of ML EGD for varices screening. They were randomly assigned into the training (n = 1154) and validation (n = 129) cohorts with a ratio of 9:1. In the training cohort, ML EGD spared 607 (52.6%) unnecessary EGDs with a missed HRV rate of 3.6%. In the validation cohort, ML EGD spared 75 (58.1%) EGDs with a missed HRV rate of 1.4%. To externally test the performance of ML EGD, 966 patients from 14 university hospitals in China (test cohort 1) and 545 from 2 hospitals in Singapore and India (test cohort 2) comprised the 2 test cohorts. In test cohort 1, ML EGD spared 506 (52.4%) EGDs with a missed HRV rate of 2.8%. In test cohort 2, ML EGD spared 224 (41.1%) EGDs with a missed HRV rate of 3.1%. When compared with the Baveno VI criteria, ML EGD spared more screening EGDs in all cohorts (training cohort, 52.6% vs 29.4%; validation cohort, 58.1% vs 44.2%; test cohort 1, 52.4% vs 26.5%; test cohort 2, 41.1% vs 21.1%, respectively; P < .001). CONCLUSIONS: We identified a novel model based on liver stiffness, platelet count, and total bilirubin, named ML EGD, as a free web-based calculator. ML EGD could efficiently help rule out HRV and avoid unnecessary EGDs in patients with compensated cirrhosis. (Clinical trial registration number: NCT04307264.).

Perilipin2 inhibits the replication of hepatitis B virus deoxyribonucleic acid by regulating autophagy under high-fat conditions.

BACKGROUND: Chronic hepatitis B virus (HBV) infection is often associated with increased lipid deposition in hepatocytes. However, when combined with non-alcoholic fatty liver disease or hyperlipidemia, it tends to have a lower HBV deoxyribonucleic acid (DNA) load. The relationship between lipid metabolism and HBV DNA replication and its underlying mechanisms are not well understood. AIM: To investigate the relationship between lipid metabolism and HBV DNA replication and its underlying mechanisms. METHODS: 1603 HBsAg-seropositive patients were included in the study. We first explored the relationship between patients' lipid levels, hepatic steatosis, and HBV DNA load. Also, we constructed an HBV infection combined with a hepatic steatosis cell model in vitro by fatty acid stimulation of HepG2.2.15 cells to validate the effect of lipid metabolism on HBV DNA replication in vitro. By knocking down and overexpressing Plin2, we observed whether Plin2 regulates autophagy and HBV replication. By inhibiting both Plin2 and cellular autophagy under high lipid stimulation, we examined whether the Plin2-autophagy pathway regulates HBV replication. RESULTS: The results revealed that serum triglyceride levels, high-density lipoprotein levels, and hepatic steatosis ratio were significantly lower in the HBV-DNA high load group. Logistic regression analysis indicated that hepatic steatosis and serum triglyceride levels were negatively correlated with HBV-DNA load. Stratified analysis by HBeAg showed significant negative correlations between HBV-DNA load and hepatic steatosis ratio in both HBeAg-positive and HBeAg-negative groups. An in vitro cell model was developed by stimulating HepG2.2.15 cells with palmitic acid and oleic acid to study the relationship between HBV-DNA load and lipid metabolism. The results of the in vitro experiments suggested that fatty acid treatment increased lipid droplet deposition and decreased the expression of cell supernatant HBsAg, HBeAg, and HBV DNA load. Western blot and polymerase chain reaction analysis showed that fatty acid stimulation significantly induced Plin2 protein expression and inhibited the expression of hepatocyte autophagy proteins. Inhibition of Plin2 protein expression under fatty acid stimulation reversed the reduction in HBsAg and HBeAg expression and HBV DNA load induced by fatty acid stimulation and the inhibition of cellular autophagy. Knocking down Plin2 and blocking autophagy with 3-methyladenine (3-MA) inhibited HBV DNA replication. CONCLUSION: In conclusion, lipid metabolism is a significant factor affecting HBV load in patients with HBV infection. The in vitro experiments established that fatty acid stimulation inhibits HBV replication via the Plin2-autophagy pathway.

Identification of the Level of Exosomal Protein by Parallel Reaction Monitoring Technology in HCC Patients.

Purpose: Reliable biomarkers for the diagnosis and differential diagnosis of various stages of liver cancer are lacking. In this study, we aim to detect the levels of differentially expressed proteins (DEPs) in serum exosomes of patients with different liver diseases using a sensitive method. Patients and Methods: Exosomes were purified and validated. The expression of DEPs in exosomes from patients with chronic hepatitis B (CHB), liver cirrhosis (LC) and hepatocellular carcinoma (HCC) was validated by parallel reaction monitoring (PRM) technology and Western blotting, and the biological functions were analyzed by bioinformatics analysis. Results: A total of 11 DEPs were identified by PRM technology. Significantly higher level of haptoglobin (Hp) was detected in HCC patients as compared to LC and CHB patients. HCC patients had a significantly lower level of transthyretin (TTR) in the patients with CHB. Among the patients with HCC who undertaken surgery, the postoperative levels of CRP, SERPINA3 and Heparin cofactor 2 (SERPIND1) were significantly reduced compared to their respective preoperative levels. Conclusion: Hp and TTR may be potential markers for early diagnosis of HCC. CRP, SERPINA3 and SERPIND1 may serve as potential prognostic indicators for HCC patients undertaken surgery.

Change of Cytokines in Chronic Hepatitis B Patients and HBeAg are Positively Correlated with HBV RNA, Based on Real-world Study.

Background and Aims: The natural course of chronic hepatitis B virus (HBV) infection is widely studied; however, follow-up studies of the same patients are scanty. Here, we studied the dynamic changes of serum HBV RNA and cytokines in hepatitis B virus e antigen (HBeAg)-positive patients treated with entecavir (ETV) to explore the relationship between the HBV serum viral nucleic acids and host immunity. Methods: Thirty-three chronic hepatitis B patients who are HBeAg-positive, with high virus load (HBV DNA >20,000 IU/mL), and received standard nucleos(t)ide analogue (NA) antiviral therapy (ETV) for more than 48 weeks were included. The serum levels of HBV nucleic acids and selected cytokines were measured at 0, 12, 24, and 48 weeks respectively. Results: Serum HBV RNA could still be detected while serum HBV DNA had fallen below the detection limit in patients treated with ETV. There was a strong positive correlation between HBV RNA and HBeAg, with a concomitant decrease in the secretion of cytokines from type 1 helper T (Th1)/type 2 helper T (Th2)/interleukin (IL)-17 producing T (Th17) cells. IL-4 and IL-10 were the main cytokines negatively associated with serum HBV RNA. Conclusions: HBeAg can be used to reflect the load of HBV RNA indirectly, because serum HBV RNA has not been widely used in clinical practice. Meanwhile, serum IL-4 and IL-10 might be explored in combination with HBV RNA in guiding future clinical antiviral therapy.

Research on Mfn2 Gene Expression in Hepatocellular Carcinoma and its Antitumor Mechanism.

Objective: To detect the expression level of the Mfn2 gene in hepatocellular carcinoma (HCC) and adjacent normal liver tissues and further analyze its anticancer effects. Methods: The expression levels of Mfn2, GLS1 and the autophagy-related proteins lc3b and Beclin1 in liver cancer and adjacent tissues in patients with liver cancer were detected by real-time-quantitative polymerase chain reaction (RT-qPCR). The HepG2 human HCC cell line was cultured in vitro, and the Mfn2 protein was stably expressed through transfection of a high Mfn2 expression plasmid. The Cell-Counting Kit-8 (CCK-8) method was used to observe the effect of Mfn2 overexpression on the activity of HepG2 cells. Furthermore, RT-qPCR and Western blotting were performed to detect the effects of Mfn2 overexpression on the protein expression of GLS1, Beclin1 and lc3b. Results: Compared with tissues adjacent to cancer tissues, the mRNA levels of Mfn2, GLS1, Beclin1 and lc3b in liver cancer tissues were lower. Compared with normal hepatocytes, the expression of Mfn2, Beclin1 and lc3b in HCC cells was decreased, but the expression of GLS1 was increased. Compared with the control group (NC) transfected with empty plasmid, Mfn2 overexpression led to significant time-dependent inhibition of HepG2 cell activity and GLS1 protein expression (P < .05). In addition, Mfn2 overexpression induced autophagy by triggering the expression of autophagy-related proteins Beclin-1 and lc3b in HCC cells (all P < .05). The effect of transfection with a high-dose Mfn2 plasmid was more obvious than that of transfection with a low-dose Mfn2 plasmid (all P < .05). Conclusions: The expression of Mfn2, GLS1, Beclin1 and lc3b in HCC was lower than in normal liver tissue. The expression of Mfn2, Beclin1 and lc3b in HCC cells was decreased, but the expression of GLS1 was increased. Overexpression of Mfn2 inhibited GLS1 gene expression by inhibiting the activity of HCC cells and promoted the expression of Beclin1 and lc3b to induce autophagy, thereby exerting an anticancer effect. Further research is needed to clarify the mechanism of Mfn2 activity.

Proteomic analysis revealed common, unique and systemic signatures in gender-dependent hepatocarcinogenesis.

Hepatocellular carcinoma (HCC) is the most common liver cancer and is highly malignant. Male prevalence and frequent activation of the Ras signaling pathway are distinct characteristics of HCC. However, the underlying mechanisms remain to be elucidated. By exploring Hras12V transgenic mice showing male-biased hepatocarcinogenesis, we performed a high-throughput comparative proteomic analysis based on tandem-mass-tag (TMT) labeling combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) on the tissue samples obtained from HCC (T) and their paired adjacent precancerous (P) of Hras12V transgenic male and female mice (Ras-Tg) and normal liver (W) of wild-type male and female mice (Non-Tg). The further validation and investigation were performed using quantitative real-time PCR and western blot. Totally, 5193 proteins were quantified, originating from 5733 identified proteins. Finally, 1344 differentially expressed proteins (DEPs) (quantified in all examined samples; |ratios| ≥ 1.5, p < 0.05) were selected for further analysis. Comparison within W, P, and T of males and females indicated that the number of DEPs in males was much higher than that in females. Bioinformatics analyses showed the common and unique cluster-enriched items between sexes, indicating the common and gender-disparate pathways towards HCC. Expression change pattern analysis revealed HCC positive/negative-correlated and ras oncogene positive/negative-correlated DEPs and pathways. In addition, it showed that the ras oncogene gradually and significantly reduced the responses to sex hormones from hepatocytes to hepatoma cells and therefore shrunk the gender disparity between males and females, which may contribute to the cause of the loss of HCC clinical responses to the therapeutic approaches targeting sex hormone pathways. Additionally, gender disparity in the expression levels of key enzymes involved in retinol metabolism and terpenoid backbone/steroid biosynthesis pathways may contribute to male prevalence in hepatocarcinogenesis. Further, the biomarkers, SAA2, Orm2, and Serpina1e, may be sex differences. In conclusion, common and unique DEPs and pathways toward HCC initiated by ras oncogene from sexually dimorphic hepatocytes provide valuable and novel insights into clinical investigation and practice.

Extracellular Vesicle-Associated mir-21 and mir-144 Are Markedly Elevated in Serum of Patients With Hepatocellular Carcinoma.

Aim: The aim of this study was to observe the possible change of microRNAs (miRNAs) in serum extracellular vesicles (EVs) from hepatocellular carcinoma (HCC) patients. Methods: The serum EVs were purified from 17 healthy donors, 16 chronic hepatitis B (CHB) patients and 24 HCC patients. The sequenced microRNAs in the purified EVs were analyzed to obtain highly differentially expressed genes (DEGs). Finally, the expression pattern of DEGs was validated using qRT-PCR. Results: We found that the expression of hsa-miR-21-5p and hsa-miR-144-3p were significantly higher in EVs and liver cancer tissues compared with serum and the distal liver tissues in HCC patients. The ratio of hsa-miR-144-3p/hsa-miR-21-5p was significantly decreased in the patients with CHB but significantly increased in patients with HCC developed from CHB (P < 0.05). Hsa-144-3p/hsa-miR-21-5p exhibited greater performance than alpha-fetoprotein (AUC 0.780, 95% CI 0.601-0.960, versus AUC 0.626, 95% CI 0.410-0.843) in ROC curve analysis. Conclusion: Extracellular vesicle-associated hsa-miR-21-5p and hsa-miR-144-3p are markedly elevated in serum of patients with HCC. The potential role of these microRNAs in the pathogenesis of HCC is worth of further study.

Combination of MicroRNAs and Cytokines: a Method for Better Evaluation of Acute-on-Chronic Liver Failure.

BACKGROUND: The aim was to establish expression profiles of microRNAs (miRNAs) in Peripheral Blood Mononuclear Cells (PBMC) and of plasma cytokines from the patients with hepatitis B virus related acute-on-chronic liver failure (HBV-ACLF) and high-risk of acute-on-chronic liver failure (ACLF) patients as well as healthy people and to examine the relationships between these profiles and clinical features. METHODS: Herein, we collected PBMCs and plasma from peripheral blood of HBV-ACLF and ACLF patients as well as healthy people. Microarray, real-time qPCR, and ELISA assays were used. RESULTS: In this study, we found 39 miRNAs including miR-146a, miR-150, and miR-29a downregulated and 5 miRNAs elevated in PBMCs from HBV-ACLF patients compared to healthy controls. However, elevated plasma levels of cytokines such as TNF-α, IFN-α, and TGF-ß were found in PBMCs from HBV-ACLF patients compared with the controls, but no significant difference was found between the high-risk and control groups. MiR-146a, miR-150, miR-29a, PTA, and anti-HBc were positively correlated with the survival of ACLF patients, while TNFα, IFN-α, INR, and TBiL were negatively correlated with the survival of these patients. CONCLUSIONS: Combined examination of miRNAs in PBMCs and cytokines in plasma together is a better method for monitoring and evaluating HBV-ACLF patients.

Challenges and opportunities for siRNA-based cancer treatment.

As one of the life-threatening diseases involving multi-step genetic and epigenetic disorders, cancer has long been a dynamic research area for siRNA-based therapy as half of the current siRNA-based clinical trials are involved in oncology. However, despite consistent enthusiasm in the academic world, siRNA-based cancer treatment still faces obstacles and difficulties in clinical development. In this article, we discuss key challenges facing siRNA-based cancer treatment revealed from recent clinical and preclinical studies, including chemical modification, tumour penetration, endosomal escape, target selection and off-target effects. In addition, opportunities and avenues for translating siRNA technology from bench to oncologic clinics are explored.

Molecular pathogenesis of hereditary hemochromatosis.

Hereditary hemochromatosis (HH) is an inherited iron overload disorder characterized by normal iron-driven erythropoiesis and abnormal iron metabolism, leading to excess iron deposited in parenchymal cells of liver, heart, and endocrine glands. Iron hormone, hepcidin, plays a critical role in iron homeostasis through interaction with ferroportin (FPN), a major cellular iron exporter. Hepcidin is encoded by hepcidin antimicrobial peptide (HAMP). Mutations in hepcidin and any genes that regulate the biology of hepcidin, including hemochromatosis genes (HFE), Hemojuvelin (HJV), transferring receptor 2 (TFR2) and FPN, result in hemochromatosis. The identification of hepcidin and its role will provide a better understanding for pathogenesis of HH.

Superior Performance of Aptamer in Tumor Penetration over Antibody: Implication of Aptamer-Based Theranostics in Solid Tumors.

Insufficient penetration of therapeutic agents into tumor tissues results in inadequate drug distribution and lower intracellular concentration of drugs, leading to the increase of drug resistance and resultant failure of cancer treatment. Targeted drug delivery to solid tumors followed by complete drug penetration and durable retention will significantly improve clinical outcomes of cancer therapy. Monoclonal antibodies have been commonly used in clinic for cancer treatment, but their limitation of penetrating into tumor tissues still remains because of their large size. Aptamers, as "chemical antibodies", are 15-20 times smaller than antibodies. To explore whether aptamers are superior to antibodies in terms of tumor penetration, we carried out the first comprehensive study to compare the performance of an EpCAM aptamer with an EpCAM antibody in theranostic applications. Penetration and retention were studied in in vitro three-dimensional tumorspheres, in vivo live animal imaging and mouse colorectal cancer xenograft model. We found that the EpCAM aptamer can not only effectively penetrate into the tumorsphere cores but can also be retained by tumor sphere cells for at least 24 h, while limited tumor penetration by EpCAM antibody was observed after 4 h incubation. As observed from in vivo live animal imaging, EpCAM aptamers displayed a maximum tumor uptake at around 10 min followed by a rapid clearance after 80 min, while the signal of peak uptake and disappearance of antibody appeared at 3 h and 6 h after intravenous injection, respectively. The signal of PEGylated EpCAM aptamers in xenograft tumors was sustained for 26 h, which was 4.3-fold longer than that of the EpCAM antibody. Consistently, there were 1.67-fold and 6.6-fold higher accumulation of PEGylated aptamer in xenograft tumors than that of antibody, at 3 h and 24 h after intravenous administration, respectively. In addition, the aptamer achieved at least a 4-time better tumor penetration in xenograft tumors than that of the antibody at a 200 µm distances from the blood vessels 3 h after intravenous injection. Taken together, these data indicate that aptmers are superior to antibodies in cancer theranostics due to their better tumor penetration, more homogeneous distribution and longer retention in tumor sites. Thus, aptamers are promising agents for targeted tumor therapeutics and molecular imaging.

Wilson's disease: a comprehensive review of the molecular mechanisms.

Wilson's disease (WD), also known as hepatolenticular degeneration, is an autosomal recessive inherited disorder resulting from abnormal copper metabolism. Reduced copper excretion causes an excessive deposition of the copper in many organs such as the liver, central nervous system (CNS), cornea, kidney, joints, and cardiac muscle where the physiological functions of the affected organs are impaired. The underlying molecular mechanisms for WD have been extensively studied. It is now believed that a defect in P-type adenosine triphosphatase (ATP7B), the gene encoding the copper transporting P-type ATPase, is responsible for hepatic copper accumulation. Deposited copper in the liver produces toxic effects via modulating several molecular pathways. WD can be a lethal disease if left untreated. A better understanding of the molecular mechanisms causing the aberrant copper deposition and organ damage is the key to developing effective management approaches.

Nucleic acid aptamer-guided cancer therapeutics and diagnostics: the next generation of cancer medicine.

Conventional anticancer therapies, such as chemo- and/or radio-therapy are often unable to completely eradicate cancers due to abnormal tumor microenvironment, as well as increased drug/radiation resistance. More effective therapeutic strategies for overcoming these obstacles are urgently in demand. Aptamers, as chemical antibodies that bind to targets with high affinity and specificity, are a promising new and novel agent for both cancer diagnostic and therapeutic applications. Aptamer-based cancer cell targeting facilitates the development of active targeting in which aptamer-mediated drug delivery could provide promising anticancer outcomes. This review is to update the current progress of aptamer-based cancer diagnosis and aptamer-mediated active targeting for cancer therapy in vivo, exploring the potential of this novel form of targeted cancer therapy.

Aptamer-mediated cancer gene therapy.

Cancer as a genetic disorder is one of the leading causes of death worldwide. Conventional anticancer options such as chemo- and/or radio-therapy have their own drawbacks and could not provide a cure in most cases at present. More effective therapeutic strategies with less side effects are urgently needed. Aptamers, also known as chemical antibodies, are single strand DNA or RNA molecules that can bind to their target molecules with high affinity and specificity. Such site-specific binding ability of aptamers facilitates the delivery and interaction of exogenous nucleic acids with diseased genes. Thus, aptamer-guided gene therapy has emerged as a promising anticancer strategy in addition to the classic treatment regimen. Aptamers can directly deliver anti-cancer nucleic acids, e.g. small interfering RNA, micro RNA, antimicroRNA and small hairpin RNA, to cancer cells or function as a targeting ligand to guide nanoparticles containing therapeutic nucleic acids. This review focuses on recent progress in aptamer-mediated gene therapy for the treatment of hepatocellular carcinoma and other types of cancers, shedding light on the potential of this novel approach of targeted cancer gene therapy.

Non alcoholic steatohepatitis a precursor for hepatocellular carcinoma development.

Hepatocellular carcinoma (HCC) is increasing in prevalence and is one of the most common cancers in the world. Chief amongst the risks of attaining HCC are hepatitis B and C infection, aflatoxin B1 ingestion, alcoholism and obesity. The later has been shown to promote non alcoholic fatty liver disease, which can lead to the inflammatory form non alcoholic steatohepatitis (NASH). NASH is a complex metabolic disorder that can impact greatly on hepatic function. The mechanisms by which NASH promotes HCC are only beginning to be characterized. Here in this review, we give an overview of the recent novel mechanisms published that have been associated with NASH and subsequent HCC progression. We will focus our discussion on inflammation and gut derived inflammation and how they contribute to NASH driven HCC.

Inflammation and cancer stem cells.

Cancer stem cells are becoming recognised as being responsible for metastasis and treatment resistance. The complex cellular and molecular network that regulates cancer stem cells and the role that inflammation plays in cancer progression are slowly being elucidated. Cytokines, secreted by tumour associated immune cells, activate the necessary pathways required by cancer stem cells to facilitate cancer stem cells progressing through the epithelial-mesenchymal transition and migrating to distant sites. Once in situ, these cancer stem cells can secrete their own attractants, thus providing an environment whereby these cells can continue to propagate the tumour in a secondary niche.

Cancer stem cells: A contentious hypothesis now moving forward.

Cancer stem cells are a progressive concept to account for the cell biological nature of cancer. Despite the controversies regarding the cancer stem cell model, it has the potential to provide a foundation for new innovative treatment targeting the roots of cancer. The last two years have witnessed exceptional progress in cancer stem cell research, in particular on solid tumours, which holds promise for improved treatment outcomes. Here, we review recent advances in cancer stem cell research, discuss challenges in the field and explore future strategies and opportunities in cancer stem cell studies to overcome resistance to chemotherapy.