The Roles Of Angiogenesis And Cancer Stem Cells In Sorafenib Drug Resistance In Hepatocellular Carcinoma

Integrating single cell analysis and machine learning methods reveals stem cell-related gene S100A10 as an important target for prediction of liver cancer diagnosis and immunotherapy

Background

Hepatocellular carcinoma (LIHC) poses a significant health challenge worldwide, primarily due to late-stage diagnosis and the limited effectiveness of current therapies. Cancer stem cells are known to play a role in tumor development, metastasis, and resistance to treatment. A thorough understanding of genes associated with stem cells is crucial for improving the diagnostic precision of LIHC and for the advancement of effective immunotherapy approaches.

Method

This research combines single-cell RNA sequencing with machine learning techniques to identify vital stem cell-associated genes that could act as prognostic biomarkers and therapeutic targets for LIHC. We analyzed various datasets, applying negative matrix factorization alongside machine learning algorithms to reveal gene expression patterns and construct diagnostic models. The XGBoost algorithm was specifically utilized to identify key regulatory genes related to stem cells in LIHC, and the expression levels and prognostic significance of these genes were validated experimentally.

Results

Our single-cell analysis identified 16 differential prognostic genes associated with liver cancer stem cells. Cluster analysis and diagnostic models constructed using various machine learning techniques confirmed the significance of these 16 genes in the diagnosis and immunotherapy of LIHC. Notably, the XGBoost algorithm identified S100A10 as the stem cell-related gene most relevant to the prognosis of LIHC patients. Experimental validation further supports S100A10 as a potential prognostic marker for this cancer type. Additionally, S100A10 shows a positive correlation with the stem cell marker POU5F1.

Conclusion

The results of this study highlight S100A10 as an essential predictor for liver cancer diagnosis and treatment response, particularly regarding immunotherapy. This research offers valuable insights into the molecular mechanisms underlying LIHC and suggests S100A10 as a promising target for enhancing treatment outcomes in liver cancer patients.

Isolation and identification of patient-derived liver cancer stem cells and development of personalized treatment strategies

BACKGROUND

Liver cancer stem cells (LCSCs) are thought to drive the metastasis and recurrence, however, the heterogeneity of molecular markers of LCSCs has hindered the development of effective methods to isolate them.

METHODS

This study introduced an effective approach to isolate and culture LCSCs from human primary liver cancer (HPLC), leveraging mouse embryonic fibroblasts (MEFs) as feeder cells in conjunction with using defined medium. Isolated LCSCs were further characterized by multiple approaches. Transcriptome sequencing data analysis was conducted to identify highly expressed genes in LCSCs and classify different subtypes of liver cancers.

RESULTS

Total sixteen cell strains were directly isolated from 24 tissues of three types of HPLC without sorting, seven of which could be maintained long-term culture as colony growth on MEFs, which is unique characteristics of stem cells. Even 10 of cloned cells formed the tumors in immunodeficient mice, indicating that those cloned cells were tumorgenic. The histologies and gene expression pattern of human xenografts were very similar to those of HPLC where these cloned cells were isolated. Moreover, putative markers of LCSCs were further verified to all express in cloned cells, confirming that these cells were LCSCs. These cloned LCSCs could be cryopreserved, and still maintained the feature of colony growth on MEFs after the recovery. Compared to suspension culture as conventional approach to culture LCSCs, our approach much better maintained stemness of LCSCs for a long time. To date, these cloned cells could be cultured on MEFs over 12 passages. Moreover, bioinformatics analysis of sequencing data revealed the gene expression profiles in LCSCs, and liver cancers were classified into two subtypes C1 and C2 based on genes associated with the prognosis of LCSCs. Patients of the C2 subtype, which is closely related to the extracellular matrix, were found to be sensitive to treatments such as Cisplatin, Axitinib, JAK1 inhibitors, WNT-c59, Sorafenib, and RO-3306.

CONCLUSION

In summary, this effective approach offers new insights into the molecular landscape of human liver cancers, and the identification of the C2 subtype and its unique response to the treatment pave the way for the creation of more effective, personalized therapeutic strategies.

Noncellular components in the liver cancer stem cell niche: Biology and potential clinical implications

Cancer stem cells (CSCs) are now recognized as one of the major root causes of therapy failure and tumor recurrence in hepatocellular carcinoma (HCC). Early studies in the field focused primarily on the intrinsic regulators of CSC maintenance, but in recent years, mounting evidence has demonstrated the presence and role of extrinsic regulators in the tumor microenvironment (TME) in the control of liver CSCs. In addition to direct interaction with cellular components, noncellular components, including the extracellular matrix, hypoxia, nutrient deprivation, and secreted molecules within the tumor stroma and hepatitis viruses, also play a critical role in shaping the CSC niche. In this review, we highlight how various noncellular components in the TME play a role in regulating CSCs and how CSCs secrete components to interact with the TME to generate their own niche, working hand in hand to drive tumor physiology in HCC. In addition, we describe the potential clinical applications of these findings and propose perspectives on future research of noncellular components in the liver CSC niche.

Impact of tumor suppressor genes inactivation on the multidrug resistance phenotype of hepatocellular carcinoma cells

The response of advanced hepatocellular carcinoma (HCC) to pharmacological treatments is unsatisfactory and heterogeneous. Inactivation of tumor suppressor genes (TSGs) by genetic and epigenetic events is frequent in HCC. This study aimed at investigating the impact of frequently altered TSGs on HCC chemoresistance. TSG alterations were screened by in silico analysis of TCGA-LIHC database, and their relationship with survival was investigated. These TSGs were silenced in HCC-derived cell lines using CRISPR/Cas9. TLDA was used to determine the expression of a panel of 94 genes involved in the resistome. Drug sensitivity, cell proliferation, colony formation and cell migration were assessed. The in silico study revealed the down-regulation of frequently inactivated TSGs in HCC (ARID1A, PTEN, CDH1, and the target of p53, CDKN1A). The presence of TP53 and ARID1A variants and the low expression of PTEN and CDH1 correlated with a worse prognosis of HCC patients. In PLC/PRF/5 cells, ARID1A knockout (ARID1AKO) induced increased sensitivity to cisplatin, doxorubicin, and cabozantinib, without affecting other characteristics of malignancy. PTENKO and E-CadKO showed minimal changes in malignancy, resistome, and drug response. In p53KO HepG2 cells, enhanced malignant properties and higher resistance to cisplatin, doxorubicin, sorafenib, and regorafenib were found. This was associated with changes in the resistome. In conclusion, the altered expression and function of several TSGs are involved in the heterogeneity of HCC chemoresistance and other features of malignancy, contributing to the poor prognosis of these patients. Individual identification of pharmacological vulnerabilities is required to select the most appropriate treatment for each patient.

Engineered extracellular vesicles mediated CRISPR-induced deficiency of IQGAP1/FOXM1 reverses sorafenib resistance in HCC by suppressing cancer stem cells

BACKGROUND

Sorafenib resistance poses therapeutic challenges in HCC treatment, in which cancer stem cells (CSCs) plays a crucial role. CRISPR/Cas9 can be utilized as a potential technique to overcome the drug resistance. However, a safe, efficient and target specific delivery of this platform remains challenging. Extracellular vesicles (EVs), the active components of cell to cell communication, hold promising benefits as delivery platform.

RESULTS

Herein we report the normal epithelial cell -derived EVs engineered with HN3(HLC9-EVs) show competing tumor targeting ability. Anchoring HN3 to the membrane of the EVs through LAMP2, drastically increased the specific homing of HLC9-EVs to GPC3⁺Huh-7 cancer cells rather than co-cultured GPC3^-LO2 cells. Combination therapy of HCC with sorafenib and HLC9-EVs containing sgIF to silence IQGAP1 (protein responsible for reactivation of Akt/PI3K signaling in sorafenib resistance) and FOXM1 (self-renewal transcription factor in CSCs attributed to sorafenib resistance), exhibited effective synergistic anti-cancer effect both in vitro and in vivo. Our results also showed that disruption of IQGAP1/FOXM1 resulted in the reduction of CD133⁺ population that contribute to the stemness of liver cancer cells.

CONCLUSION

By reversing sorafenib resistance using combination therapeutic approach with engineered EVs encapsulated CRISPR/Cas9 and sorafenib, our study foreshadows a path for a better, accurate, reliable and successful anti-cancer therapy in the future.

Short peptide domains of the Wnt inhibitor sFRP4 target ovarian cancer stem cells by neutralizing the Wnt β-catenin pathway, disrupting the interaction between β-catenin and CD24 and suppressing autophagy

AIMS

One of the hallmarks of cancer stem cells (CSC) is hyperactive Wnt β-catenin signaling due to the decreased presence of Wnt antagonists such as secreted frizzled related protein 4 (SFRP4). Cysteine-rich domain (CRD) and netrin-like domain (NLD) are the two functional domains of SFRP4 having anti-tumor properties. In this study, we have explored the effectiveness of short micropeptides SC-301 (from CRD) and SC-401 (from NLD) on CSC properties, EMT, apoptosis and autophagy in ovarian CSCs enriched from PA-1 and SKOV-3 cell lines.

MAIN METHODS

Gene expression analysis, Western blot and immunocytochemistry were performed on ovarian CSCs to evaluate the inhibitory potential of micropeptides to various CSC associated oncogenic properties. Co-immunoprecipitation was performed to detect the binding of CD24 to β-catenin protein complex. CYTO-ID Autophagy Detection Kit 2.0 was used to monitor autophagic flux in peptide treated CSCs.

KEY FINDINGS

It is clearly seen that the micropeptides derived from both the domains inhibit Wnt pathway, initiate apoptosis, inhibit migration and chemosensitize CSCs. Specifically, CD24, a defining marker of ovarian CSC was suppressed by peptide treatment. Notably, interaction between CD24 and β-catenin was disrupted upon peptide treatment. SFRP4 peptide treatment also suppressed the autophagic process which is crucial for CSC survival.

SIGNIFICANCE

The study demonstrated that although both peptides have inhibitory effects, SC-401 was emphatically more effective in targeting CSC properties and down regulating the Wnt β-catenin machinery.

Cancer Stem Cell and Hepatic Stellate Cells in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common liver cancer. It is highly lethal and has high recurrence. Death among HCC patients occur mainly due to tumor progression, recurrence, metastasis, and chemoresistance. Cancer stem cells (CSCs) are cell subpopulations within the tumor that promote invasion, recurrence, metastasis, and drug resistance. Hepatic stellate cells (HSCs) are important components of the tumor microenvironment (TME) responsible for primary secretory ECM proteins during liver injury and inflammation. These cells promote fibrogenesis, infiltrate the tumor stroma, and contribute to HCC development. Interactions between HSC and CSC and their microenvironment help promote carcinogenesis through different mechanisms. This review summarizes the roles of CSCs and HSCs in establishing the TME in primary liver tumors and describes their involvement in HCC chemoresistance.

Orlistat Resensitizes Sorafenib-Resistance in Hepatocellular Carcinoma Cells through Modulating Metabolism

Sorafenib is one of the options for advanced hepatocellular carcinoma treatment and has been shown to extend median overall survival. However, sorafenib resistance often develops a few months after treatment. Hence, developing various strategies to overcome sorafenib resistance and understand the possible mechanisms is urgently needed. We first established sorafenib-resistant hepatocellular carcinoma (HCC) cells. Then, we found that sorafenib-resistant Huh7 cells (Huh7/SR) exhibit higher glucose uptakes and express elevated fatty acid synthesis and glucose metabolism-related proteins than their parental counterparts (Huh7). The current study investigated whether sorafenib resistance could be reversed by suppressing fatty acid synthesis, using a fatty acid synthase (FASN) inhibitor, orlistat, in HCC cells. FASN inhibition-caused changes in protein expressions and cell cycle distribution were analyzed by Western blot and flow cytometry, and changes in glucose uptakes were also evaluated by ¹⁸F-FDG uptake. Orlistat remarkably enhanced the cytotoxicity of sorafenib in both Huh7 and Huh7/SR cells, and flow cytometry showed that combination treatment significantly increased the sub-G1 population in both cell lines. Western blot revealed that the combination treatment effectively increased the ratio of Bax/Bcl-2 and decreased expressions of pERK; additionally, the combination treatment also strongly suppressed fatty acid synthesis-related proteins (e.g., FASN and SCD) in both cell lines. Lastly, the ¹⁸F-FDG uptake was repressed by the combination treatment in both cell lines. Our results indicated that orlistat-mediated FASN inhibition could overcome sorafenib resistance and enhance cell killing in HCC by changing cell metabolism.

Enhanced Vasculogenic Capacity Induced by 5-Fluorouracil Chemoresistance in a Gastric Cancer Cell Line

Chemotherapy is still widely used as a coadjutant in gastric cancer when surgery is not possible or in presence of metastasis. During tumor evolution, gatekeeper mutations provide a selective growth advantage to a subpopulation of cancer cells that become resistant to chemotherapy. When this phenomenon happens, patients experience tumor recurrence and treatment failure. Even if many chemoresistance mechanisms are known, such as expression of ATP-binding cassette (ABC) transporters, aldehyde dehydrogenase (ALDH1) activity and activation of peculiar intracellular signaling pathways, a common and universal marker for chemoresistant cancer cells has not been identified yet. In this study we subjected the gastric cancer cell line AGS to chronic exposure of 5-fluorouracil, cisplatin or paclitaxel, thus selecting cell subpopulations showing resistance to the different drugs. Such cells showed biological changes; among them, we observed that the acquired chemoresistance to 5-fluorouracil induced an endothelial-like phenotype and increased the capacity to form vessel-like structures. We identified the upregulation of thymidine phosphorylase (TYMP), which is one of the most commonly reported mutated genes leading to 5-fluorouracil resistance, as the cause of such enhanced vasculogenic ability.

GNS561, a New Autophagy Inhibitor Active against Cancer Stem Cells in Hepatocellular Carcinoma and Hepatic Metastasis from Colorectal Cancer

Patients with advanced hepatocellular carcinoma (HCC) or metastatic colorectal cancer (mCRC) have a very poor prognosis due to the lack of efficient treatments. As observed in several other tumors, the effectiveness of treatments is mainly hampered by the presence of a highly tumorigenic sub-population of cancer cells called cancer stem cells (CSCs). Indeed, CSCs are resistant to chemotherapy and radiotherapy and can regenerate the tumor bulk. Hence, innovative drugs that are efficient against both bulk tumor cells and CSCs would likely improve cancer treatment. In this study, we demonstrated that GNS561, a new autophagy inhibitor that induces lysosomal cell death, showed significant activity against not only the whole tumor population but also a sub-population displaying CSC features (high ALDH activity and tumorsphere formation ability) in HCC and in liver mCRC cell lines. These results were confirmed in vivo in HCC from a DEN-induced cirrhotic rat model in which GNS561 decreased tumor growth and reduced the frequency of CSCs (CD90+CD45-). Thus, GNS561 offers great promise for cancer therapy by exterminating both the tumor bulk and the CSC sub-population. Accordingly, a global phase 1b clinical trial in liver cancers was recently completed.

Sorafenib combined with dasatinib therapy inhibits cell viability, migration, and angiogenesis synergistically in hepatocellular carcinoma

PURPOSE

Sorafenib is a multikinase inhibitor used for treatment of advanced hepatocellular carcinoma. Sorafenib resistance may be related to Src-induced cell migration and angiogenesis, which are regulated by cancer stem cell activation and release of vascular endothelial growth factor. Dasatinib is a Src inhibitor that inhibits Src phosphorylation and suppresses Src-associated cell migration and angiogenesis. This study investigated whether combined treatment with dasatinib can overcome sorafenib resistance.

METHODS

Hepatoma cell lines were used for sorafenib and/or dasatinib treatment. Cell viability, cell migration, molecular expressions, and release of vascular endothelial growth factor by hepatoma cells were evaluated. Hepatoma cell culture medium was applied on human umbilical vein endothelial cells to monitor angiogenesis promoted by the hepatoma cells.

RESULTS

Sorafenib and dasatinib combined therapy suppressed cell viability of hepatoma cells synergistically. Dasatinib suppressed sorafenib-induced cell migration via inhibiting sorafenib-induced Src/FAK phosphorylation, cell-to-cell contact and cancer stem cell activation. Culture medium from Chang liver and PLC/PRF/5 cells suppressed angiogenesis of human umbilical vein endothelial cells with any treatment, whereas sorafenib-treated medium of HepG2 cells induced angiogenesis. This sorafenib-induced angiogenesis was then suppressed by dasatinib. Vascular endothelial growth factor released from hepatoma cells was also inhibited by combined treatment.

CONCLUSION

Src/FAK phosphorylation and cancer stem cell activation inducing cell migration and angiogenesis may be the key factors of sorafenib resistance. Sorafenib and dasatinib combined treatment suppresses cell migration and angiogenesis by inhibiting the Src/FAK phosphorylation, cell-to-cell contact, cancer stem cell activation, and release of vascular endothelial growth factor.

IL-6/STAT3 Signaling Contributes to Sorafenib Resistance in Hepatocellular Carcinoma Through Targeting Cancer Stem Cells

Background

Sorafenib is the standard first-line treatment for advanced hepatocellular carcinoma (HCC), even though acquired resistance to sorafenib has been found in many HCC patients, resulting in poor prognosis. Accumulating evidence demonstrates that liver cancer stem cells (LCSCs) contribute to sorafenib resistance in HCC. The inflammatory factor interleukin 6 (IL-6) plays a role in sorafenib resistance in HCC. However, the mechanism by which IL-6 in LCSCs is involved in the process of HCC sorafenib resistance remains elusive.

Methods

In this study, the sorafenib-resistant cell line PLC/PRF/5-R was generated by the concentration gradient method, and cell viability was determined by the CCK-8 assay. LCSCs were isolated from the PLC/PRF/5-R cell line by flow cytometry, and tumorigenesis was confirmed in nude mice. Blockade of IL-6 cells was achieved by lentiviral-mediated interference. The protein levels of stem cell markers (EpCAM, CD44), stemness markers (Oct3/4, β-catenin), and hepatocyte differentiation markers (glucose-6-phosphate, AFP) were measured by Western blotting analysis. Finally, a xenograft model was used to evaluate the function of IL-6 in the sorafenib resistance of HCC.

Results

The stable sorafenib-resistant HCC cell line PLC/PRF/5-R was established and showed significant epithelial–mesenchymal transition (EMT) characteristics; the isolated resistant LCSCs from PLC/PRF/5-R were more tumorigenic than the control LCSCs. We showed that IL-6, IL-6R, STAT3 and GP130 expression were dramatically increased in resistant LCSCs compared to control LCSCs. Downregulation of IL-6 expression with short hairpin RNA (shRNA) restored sorafenib sensitivity in resistant LCSCs, suggesting the critical roles of IL-6/STAT3 in inducing sorafenib resistance. Furthermore, a xenograft tumor model showed that IL-6 downregulation improved the antitumor effect of sorafenib.

Conclusion

LCSCs play an important role in sorafenib-resistant HCC, and inhibition of the IL-6/STAT3 signaling pathway improves the antitumor effects of sorafenib against HCC in vitro and in vivo. These findings demonstrate that IL-6 in LCSCs may function as a novel target for combating sorafenib resistance in HCC.

Roles of circRNAs in the tumour microenvironment

The tumour microenvironment (TME) constitutes the area surrounding the tumour during its development and has been demonstrated to play roles in cancer-related diseases through crosstalk with tumour cells. Circular RNAs (circRNAs) are a subpopulation of endogenous noncoding RNAs (ncRNAs) that are ubiquitously expressed in eukaryotes and have multiple biological functions in the regulation of cancer onset and progression. An increasing number of studies have shown that circRNAs participate in the multifaceted biological regulation of the TME. However, details on the mechanisms involved have remained elusive until now. In this review, we analyse the effects of circRNAs on the TME from various perspectives, including immune surveillance, angiogenesis, hypoxia, matrix remodelling, exo-circRNAs and chemoradiation resistance. Currently, the enormous potential for circRNA use in targeted therapy and as noninvasive biomarkers have drawn our attention. We emphasize the prospect of targeting circRNAs as an essential strategy to regulate TME, overcome cancer resistance and improve therapeutic outcomes.

Recent Advancements of Nanomedicine towards Antiangiogenic Therapy in Cancer

Angiogenesis is a process of generation of de-novo blood vessels from already existing vasculature. It has a crucial role in different physiological process including wound healing, embryonic development, and tumor growth. The methods by which therapeutic drugs inhibit tumor angiogenesis are termed as anti-angiogenesis cancer therapy. Developments of angiogenic inhibiting drugs have various limitations causing a barrier for successful treatment of cancer, where angiogenesis plays an important role. In this context, investigators developed novel strategies using nanotechnological approaches that have demonstrated inherent antiangiogenic properties or used for the delivery of antiangiogenic agents in a targeted manner. In this present article, we decisively highlight the recent developments of various nanoparticles (NPs) including liposomes, lipid NPs, protein NPs, polymer NPs, inorganic NPs, viral and bio-inspired NPs for potential application in antiangiogenic cancer therapy. Additionally, the clinical perspectives, challenges of nanomedicine, and future perspectives are briefly analyzed.