Targeting Liver Cancer Stem Cells: An Alternative Therapeutic Approach for Liver Cancer

Seedless black Vitis vinifera polyphenols suppress hepatocellular carcinoma in vitro and in vivo by targeting apoptosis, cancer stem cells, and proliferation

Hepatocellular carcinoma (HCC) is an aggressive tumor and one of the most challenging cancers to treat. Here, we evaluated the in vitro and in vivo ameliorating impacts of seedless black Vitis vinifera (VV) polyphenols on HCC. Following the preparation of the VV crude extract (VVCE) from seedless VV (pulp and skin), three fractions (VVF1, VVF2, and VVF3) were prepared. The anticancer potencies of the prepared fractions, compared to 5-FU, were assessed against HepG2 and Huh7 cells. In addition, the effects of these fractions on p-dimethylaminoazobenzene-induced HCC in mice were evaluated. The predicted impacts of selected phenolic constituents of VV fractions on the activity of essential HCC-associated enzymes (NADPH oxidase "NADPH-NOX2", histone deacetylase 1 "HDAC1", and sepiapterin reductase "SepR") were analyzed using molecular docking. The results showed that VVCE and its fractions induced apoptosis and collapsed CD133+ stem cells in the studied cancer cell lines with an efficiency greater than 5-FU. VVF1 and VVF2 exhibited the most effective anticancer fractions in vitro; therefore, we evaluated their influences in mice. VVF1 and VVF2 improved liver morphology and function, induced apoptosis, and lowered the fold expression of various crucial genes that regulate cancer stem cells and other vital pathways for HCC progression. For most of the examined parameters, VVF1 and VVF2 had higher potency than 5-FU, and VVF1 showed more efficiency than VVF2. The selected phenolic compounds displayed competitive inhibitory action on NADPH-NOX2, HDAC1, and SepR. In conclusion, these findings declare that VV polyphenolic fractions, particularly VVF1, could be promising safe anti-HCC agents.

Nanoparticles and Mesenchymal Stem Cell (MSC) Therapy for Cancer Treatment: Focus on Nanocarriers and a si-RNA CXCR4 Chemokine Blocker as Strategies for Tumor Eradication In Vitro and In Vivo

Mesenchymal stem cells (MSCs) have a high tropism for the hypoxic microenvironment of tumors. The combination of nanoparticles in MSCs decreases tumor growth in vitro as well as in rodent models of cancers in vivo. Covalent conjugation of nanoparticles with the surface of MSCs can significantly increase the drug load delivery in tumor sites. Nanoparticle-based anti-angiogenic systems (gold, silica and silicates, diamond, silver, and copper) prevented tumor growth in vitro. For example, glycolic acid polyconjugates enhance nanoparticle drug delivery and have been reported in human MSCs. Labeling with fluorescent particles (coumarin-6 dye) identified tumor cells using fluorescence emission in tissues; the conjugation of different types of nanoparticles in MSCs ensured success and feasibility by tracking the migration and its intratumor detection using non-invasive imaging techniques. However, the biosafety and efficacy; long-term stability of nanoparticles, and the capacity for drug release must be improved for clinical implementation. In fact, MSCs are vehicles for drug delivery with nanoparticles and also show low toxicity but inefficient accumulation in tumor sites by clearance of reticuloendothelial organs. To solve these problems, the internalization or conjugation of drug-loaded nanoparticles should be improved in MSCs. Finally, CXCR4 may prove to be a promising target for immunotherapy and cancer treatment since the delivery of siRNA to knock down this alpha chemokine receptor or CXCR4 antagonism has been shown to disrupt tumor-stromal interactions.

IGF2BP2 promotes glycolysis and hepatocellular carcinoma stemness by stabilizing CDC45 mRNA via m6A modification

A growing number of studies have shown the prognostic importance of Cell division cycle protein 45 (CDC45) in hepatocellular carcinoma (HCC). This study aims to investigate the biological function and mechanism of CDC45 in HCC. The differential expression and prognostic significance of CDC45 in HCC and normal tissues were analyzed by bioinformatics. CDC45 was knocked down and the biological effects of CDC45 in HCC in vitro and in vivo were measured. Subsequently, using RNA m6A colorimetry and Methylated RNA Immunoprecipitation (MeRIP), the levels of m6A modification of total RNA and CDC45 were evaluated in cells. RIP was applied to establish that CDC45 and insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) interact. A test using actinomycin D was performed to gauge the stability of the CDC45 mRNA. Furthermore, the regulatory role of IGF2BP2 on CDC45 expression in HCC progression was explored by overexpressing IGF2BP2. High expression of CDC45 was correlated with poor prognosis in HCC patients. Knocking down CDC45 inhibited HCC cell proliferation, migration, invasion, EMT, stemness, and glycolysis, and promoted apoptosis, which was verified through in vitro experiments. Additionally, IGF2BP2 was highly expressed in HCC cells, and it was found to interact with CDC45. Knocking down IGF2BP2 resulted in reduced stability of CDC45 mRNA. Moreover, overexpression of IGF2BP2 promoted HCC cell proliferation, migration, invasion, EMT, stemness, and glycolysis, while inhibiting apoptosis, which was reversed by knocking down CDC45. In general, IGF2BP2 promoted HCC glycolysis and stemness by stabilizing CDC45 mRNA via m6A modification. [Figure: see text].

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.

Identification of a necroptosis-related gene signature as a novel prognostic biomarker of cholangiocarcinoma

Background

Cholangiocarcinoma (CHOL) is the most prevalent type of malignancy and the second most common form of primary liver cancer, resulting in high rates of morbidity and mortality. Necroptosis is a type of regulated cell death that appears to be involved in the regulation of several aspects of cancer biology, including tumorigenesis, metastasis, and cancer immunity. This study aimed to construct a necroptosis-related gene (NRG) signature to investigate the prognosis of CHOL patients using an integrated bioinformatics analysis.

Methods

CHOL patient data were acquired from the Gene Expression Omnibus (GEO) (GSE89748, GSE107943) and The Cancer Genome Atlas (TCGA) databases, with NRGs data from the necroptosis pathway in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Univariate and multivariate regression analyses were performed to establish the NRG signatures. Kaplan-Meier (KM) curves were used to evaluate the prognosis of patients with CHOL. Functional enrichment analysis was performed to identify key NRG-associated biological signaling pathways. We also applied integrative multi-omics analysis to the high- and low-risk score groups. Spearman's rank correlation was used to clarify the relationship between the NRG signature and immune infiltration.

Results

65 differentially expressed (DE) NRGs were screened, five of which were selected to establish the prognostic signature of NRG_S based on multivariate Cox regression analysis. We observed that low-risk patients survived significantly longer than high-risk patients. We found that patients with high-risk scores experienced higher immune cell infiltration, drug resistance, and more somatic mutations than patients with low-risk scores. We further found that sensitivities to GW843682X, mitomycin C, rapamycin, and S-trityl-L-cysteine were significantly higher in the low-risk group than in the high-risk group. Finally, we validated the expression of five NRGs in CHOL tissues using the TCGA database, HPA database and our clinical data.

Conclusion

These findings demonstrate that the five-NRG prognostic signature for CHOL patients is reasonably accurate and valid, and it may prove to be of considerable value for the treatment and prognosis of CHOL patients in the future.

Biology of cancer; from cellular and molecular mechanisms to developmental processes and adaptation

Cancer research has been largely focused on the cellular and molecular levels of investigation. Recent data show that not only the cell but also the extracellular matrix plays a major role in the progression of malignancy. In this way, the cells and the extracellular matrix create a specific local microenvironment that supports malignant development. At the same time, cancer implies a systemic evolution which is closely related to developmental processes and adaptation. Consequently, there is currently a real gap between the local investigation of cancer at the microenvironmental level, and the pathophysiological approach to cancer as a systemic disease. In fact, the cells and the matrix are not only complementary structures but also interdependent components that act synergistically. Such relationships lead to cell-matrix integration, a supracellular form of biological organization that supports tissue development. The emergence of this supracellular level of organization, as a structure, leads to the emergence of the supracellular control of proliferation, as a supracellular function. In humans, proliferation is generally involved in developmental processes and adaptation. These processes suppose a specific configuration at the systemic level, which generates high-order guidance for local supracellular control of proliferation. In conclusion, the supracellular control of proliferation act as an interface between the downstream level of cell division and differentiation, and upstream level of developmental processes and adaptation. Understanding these processes and their disorders is useful not only to complete the big picture of malignancy as a systemic disease, but also to open new treatment perspectives in the form of etiopathogenic (supracellular or informational) therapies.

Preparation and pharmacokinetics of glycyrrhetinic acid and cell transmembrane peptides modified with liposomes for liver targeted-delivery

The article presents a hepatocellular carcinoma cell surface-specific ligand glycyrrhetinic acid (GA) and cell-penetrating peptide (TAT) with good cell membrane penetration to modify the anti-tumor drug pingyangmycin (PYM) liver delivery system, which achieve targeted delivery of drugs and improve anti-tumor efficiency. In this study, we synthesized the pingyangmycin liposome modified by glycyrrhetinic acid and cell penetrating peptide(GA-TAT-PYM-L) and evaluated the anti-tumor effect of GA-TAT-PYM-Lin vitro. Using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenylte-trazolium bromidecell proliferation method, GA-TAT-PYM-L had a stronger inhibitory effect on HepG2 cells than the free drug PYM at the same concentration. Acridine orange-ethidium bromide staining assays showed that GA-TAT-PYM-L had stronger apoptosis promotion effects on HepG2 cells in comparison to PYM. Pharmacokinetic studies indicated that, compared with PYM, GA-TAT-PYM-L enhanced mean residence time (MRT_0-∞) and area under curve (AUC_0-∞) by about 2.79-fold and 2.45-fold. TheT_1/2was prolonged to 140.23 ± 14.13 min. Tissue distribution results showed that the PYM concentrations in livers from the GA-TAT-PYM-L group were always higher than other tissues at each monitoring period after 5 min, indicating that GA-TAT-PYM-L can achieve liver targeting.

Screening and Validation of a Carvacrol-Targeting Viability-Regulating Protein, SLC6A3, in Liver Hepatocellular Carcinoma

Background

Liver hepatocellular carcinoma (LIHC) is the second leading cause of tumor-related death in the world. Carvacrol was also found to inhibit multiple cancer types. Here, we proposed that Carvacrol inhibited LIHC.

Methods

We used MTT assay to determine the inhibition of Carvacrol on LIHC cells. BATMAN-TCM was used to predict targets of Carvacrol. These targets were further screened by their survival association and expression in cancer using TCGA data. The bioinformatic screened candidates were further validated in in vitro experiments and clinical samples. Finally, docking models of the interaction of Carvacrol and target protein were conducted.

Results

Carvacrol inhibited the viability of LIHC cell lines. 40 target genes of Carvacrol were predicted, 8 of them associated with survival. 4 genes were found differentially expressed in LIHC vs. normal liver. Among these genes, the expression of SLC6A3 and SCN4A was found affected by Carvacrol in LIHC cells, but only SLC6A3 correlated with the viability inhibition of Carvacrol on LIHC cell lines. A docking model of the interaction of Carvacrol and SLC6A3 was established with a good binding affinity. SLC6A3 knockdown and expression revealed that SLC6A3 promoted the viability of LIHC cells.

Conclusion

Carvacrol inhibited the viability of LIHC cells by downregulating SLC6A3.

Treatment of Liver Cancer: Role of the Traditional Mongolian Medicine

Liver cancer is an extraordinarily heterogeneous malignancy with relatively high mortality and increasing incidence rate among the so far identified cancers. Improvements in liver cancer therapy have been made in the past decades, but therapeutics against liver cancer are still limited. Traditional Mongolian Medicine, formed and developed by the Mongolian people to maintain health in the medical practice of fighting against diseases, has been recognized as one of the key components of the world healthcare system. Traditional Mongolian Medicine has been used to treat various malignancies, including liver cancer, for a long time in Asia and its advantages have become more and more apparent. Herein, this review made a comprehensive summary of Traditional Mongolian Medicine, including the ideas in the liver cancer treatment, sources of medicines or prescriptions, traditional applications, modern pharmacological research, chemical structure and mechanisms of several monomer compounds isolated from Traditional Mongolian Medicine, with a view to finding promising drugs against liver cancer and expanding the clinical application of Traditional Mongolian Medicine in liver cancer therapy.

Chronic alcohol exposure induces hepatocyte damage by inducing oxidative stress, SATB2 and stem cell‐like characteristics, and activating lipogenesis

Alcohol is a risk factor for hepatocellular carcinoma (HCC). However, the molecular mechanism by which chronic alcohol consumption contributes to HCC is not well understood. The purpose of the study was to demonstrate the effects of chronic ethanol exposure on the damage of human normal hepatocytes. Our data showed that chronic exposure of hepatocytes with ethanol induced changes similar to transformed hepatocytes that is, exhibited colonies and anchorage‐independent growth. These damaged hepatocytes contained high levels of reactive oxygen species (ROS) and showed induction of the SATB2 gene. Furthermore, damaged hepatocytes gained the phenotypes of CSCs which expressed stem cell markers (CD133, CD44, CD90, EpCAM, AFP and LGR5), and pluripotency maintaining factors (Sox‐2, POU5F1/Oct4 and KLF‐4). Ethanol exposure also induced Nanog, a pluripotency maintaining transcription factor that functions in concert with Oct4 and SOX‐2. Furthermore, ethanol induced expression of EMT‐related transcription factors (Snail, Slug and Zeb1), N‐Cadherin, and inhibited E‐cadherin expression in damaged hepatocytes. Ethanol enhanced recruitment of SATB2 to promoters of Bcl‐2, Nanog, c‐Myc, Klf4 and Oct4. Ethanol also induced activation of the Wnt/TCF‐LEF1 pathway and its targets (Bcl‐2, Cyclin D1, AXIN2 and Myc). Finally, ethanol induced hepatocellular steatosis, SREBP1 transcription, and modulated the expression of SREBP1c, ACAC, ACLY, FASN, IL‐1β, IL‐6, TNF‐α, GPC3, FLNB and p53. These data suggest that chronic alcohol consumption may contribute towards the development of HCC by damaging normal hepatocytes with the generation of inflammatory environment, induction of SATB2, stem cell‐like characteristics, and cellular steatosis.

Matrix Stiffness Potentiates Stemness of Liver Cancer Stem Cells Possibly via the Yes-Associated Protein Signal

A hepatocellular carcinoma tissue has mechanical heterogeneity, where the stiffness gradually increases from the core to the invasion front. Furthermore, there is evidence that stem cells from liver cancer (LCSCs) preferentially enrich the invasion front, exhibiting the stiffest modulus in the tumor. LCSCs have the features of stem/progenitor cells and play a vital part in liver cancer development. However, whether matrix stiffness affects LCSC stemness remains unclear. Here, we established a three-dimensional hydrogel for culturing LCSCs to simulate the stiffness of the core and the invasion front of a liver cancer tissue. The results showed that a stiffer matrix (72.2 ± 0.90 kPa) significantly potentiated LCSC stemness as compared with a soft matrix (7.7 ± 0.41 kPa). Moreover, Yes-associated protein signaling might mediate this promotion. Together, our findings illustrate the relationship between matrix stiffness and LCSC stemness, which may aid the production of novel treatment approaches against liver cancer.

Silencing PFKP restrains the stemness of hepatocellular carcinoma cells

BACKGROUND

Glycolysis reprogramming is deeply involved in the progression of hepatocellular carcinoma (HCC), in which HCC cells with stemness traits play important roles as well. Thus, whether platelet isoform of phosphofructokinase 1 (PFKP), a rate-limiting enzyme in glycolysis, contributes to the maintenance of stemness of HCC cells is worth investigation.

METHODS

PFKP levels were compared between human hepatocellular carcinoma and adjacent normal tissues by Western blotting and immunohistochemistry. The relationship between PFKP expression and clinic pathological features was also analyzed. Furthermore, the colony formation capabilities and the levels of stemness markers (ALDH1, CD44, CD133, Sox-2) as well as β-catenin were compared between HCC cells either undergoing PFKP silencing or overexpression.

RESULTS

PFKP levels were higher in HCC as compared to normal hepatic tissues. Silencing PFKP decreased HCC proliferation, colony formation capabilities, and levels of stemness markers and β-catenin; whereas overexpressing PFKP demonstrated the opposite effects.

CONCLUSION

PFKP promoted HCC proliferation and contributed to the maintenance of HCC stemness. Silencing PFKP could restrain the stemness of HCC, suggesting that PFKP may be a potential therapeutic target for HCC treatment.

Multiple targeted self-emulsifying compound RGO reveals obvious anti-tumor potential in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly vascularized, inflammatory, and abnormally proliferating tumor. Monotherapy is often unable to effectively and comprehensively inhibit the progress of HCC. In present study, we selected ginsenoside Rg3, ganoderma lucidum polysaccharide (GLP), and oridonin as the combined therapy. These three plant monomers play important roles in anti-angiogenesis, immunological activation, and apoptosis promotion, respectively. However, the low solubility and poor bioavailability seriously hinder their clinical application. To resolve these problems, we constructed a new drug, Rg3, GLP, and oridonin self-microemulsifying drug delivery system (RGO-SMEDDS). We found that this drug effectively inhibits the progression of HCC by simultaneously targeting multiple signaling pathways. RGO-SMEDDS restored immune function by suppressing the production of immunosuppressive cytokine and M2-polarized macrophages, reduced angiogenesis by downregulation of vascular endothelial growth factor and its receptor, and retarded proliferation by inhibiting the epidermal growth factor receptor EGFR/AKT/epidermal growth factor receptor/protein kinase B/glycogen synthase kinase-3 (GSK3) signaling pathway. In addition, RGO-SMEDDS showed considerable safety in acute toxicity tests. Results from this study show that RGO-SMEDDS is a promising therapy for the treatment of HCC.

Mechanisms involved in selecting and maintaining neuroblastoma cancer stem cell populations, and perspectives for therapeutic targeting

Pediatric neuroblastomas (NBs) are heterogeneous, aggressive, therapy-resistant embryonal tumours that originate from cells of neural crest (NC) origin and in particular neuroblasts committed to the sympathoadrenal progenitor cell lineage. Therapeutic resistance, post-therapeutic relapse and subsequent metastatic NB progression are driven primarily by cancer stem cell (CSC)-like subpopulations, which through their self-renewing capacity, intermittent and slow cell cycles, drug-resistant and reversibly adaptive plastic phenotypes, represent the most important obstacle to improving therapeutic outcomes in unfavourable NBs. In this review, dedicated to NB CSCs and the prospects for their therapeutic eradication, we initiate with brief descriptions of the unique transient vertebrate embryonic NC structure and salient molecular protagonists involved NC induction, specification, epithelial to mesenchymal transition and migratory behaviour, in order to familiarise the reader with the embryonic cellular and molecular origins and background to NB. We follow this by introducing NB and the potential NC-derived stem/progenitor cell origins of NBs, before providing a comprehensive review of the salient molecules, signalling pathways, mechanisms, tumour microenvironmental and therapeutic conditions involved in promoting, selecting and maintaining NB CSC subpopulations, and that underpin their therapy-resistant, self-renewing metastatic behaviour. Finally, we review potential therapeutic strategies and future prospects for targeting and eradication of these bastions of NB therapeutic resistance, post-therapeutic relapse and metastatic progression.

Pluripotency inducing Yamanaka factors: role in stemness and chemoresistance of liver cancer

Introduction: Liver cancer is a major cause of mortality and is characterized by the transformation of cells into an uncontrolled mass of tumor cells with many genetic and epigenetic changes, which lead to the development of tumors. A small subpopulation of cell population known as Cancer Stem Cells (CSCs) is responsible for cancer stemness and chemoresistance. Yamanaka factors [octamer-binding transcription factor 4 (OCT4), SRY (sex-determining region Y)-box 2 (SOX2), kruppel-like factor 4 (KLF4), and Myelocytomatosis (MYC); OSKM] are responsible for cancer cell stemness, chemoresistance, and recurrence.Area covered: We cover recent discoveries and investigate the role of OSKM in inducing pluripotency and stem cell-like properties in various cancers with special emphasis on liver cancer. We review Yamanaka factors' role in stemness and chemoresistance of liver cancer.Expert opinion: In CSCs, including liver CSCs, the deregulation of various signaling pathways is one of the major reasons for stemness and drug resistance and is primarily due to OSKM. OSKM are responsible for tumor heterogeneity which renders targeting drug useless after a certain period. These factors can be exploited to understand the underlying mechanism of cancer stemness and resistance to chemotherapeutic drugs.

A novel focal adhesion related gene signature for prognostic prediction in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly heterogeneous disease. Reduced expression of focal adhesion is considered as an important prerequisite for tumor cell invasion and metastasis. However, the prognostic value of focal adhesion related genes in HCC remains to be further determined. In this study, RNA expression profiles were downloaded from public databases. A five focal adhesion related gene signature model was established by the least absolute shrinkage and selection operator Cox regression analysis, which categorized patients into high- and low-risk groups. Multivariate Cox regression analysis showed that the risk score was an independent predictor for overall survival. Single-sample gene set enrichment analysis revealed that immune status was different between the two risk groups, and tumor-related pathways were enriched in high-risk group. The risk score was significantly associated with tumor grade, tumor stage, immune scores, and immune infiltrate types. Pearson correlation showed that the expression level of prognostic genes was associated with anti-tumor drug sensitivity. Besides, the mRNA and protein expression of prognostic genes was significantly different between HCC tissues and adjacent non-tumorous tissues in our separate cohort. Taken together, a novel focal adhesion related gene signature can be used for prognostic prediction in HCC, which may be a therapeutic alternative.

Simultaneously target of normal and stem cells-like gastric cancer cells via cisplatin and anti-CD133 CAR-T combination therapy

CD133 + cancer stem cells mediate chemoresistance in multiple aggressive cancers, and anti-CD133 chimeric antigen receptor T (CAR-T) cells are designed to selectively target cisplatin-resistant gastric cancer stem cells in this investigation. The relative CD133 expression was detected in gastric cancer patients before and after cisplatin treatment. Anti-CD133 CAR-T cells were incubated with cisplatin-exposed CD133⁺ BGC-823 cells to evaluate the killing efficacy. At the same time, the canonical T cell activation markers were assayed by fluorescence-activated cell sorting, and the functional cytokine profile was detected with enzyme-linked immunosorbent assays. In addition to the percentage of CD133 positive stem cell-like cells, the volume and weight of subcutaneous tumors in BGC-823, KATO III and MKN-28 xenograft models were measured to evaluate the anti-tumor activity of cisplatin and anti-CD133 CAR-T combination strategy. After cisplatin treatment, both human samples and BGC-823 cells showed up-regulated CD133 expression. Anti-CD133 CAR-T cells exhibited pronounced killing efficiency against cisplatin-exposed CD133⁺ BGC-823 cells with up-regulated activation markers and cytotoxicity cytokine production. Moreover, cisplatin and anti-CD133 CAR-T combination treatment inhibited tumor progression in three different xenograft models with diminished CD133 positive stem cell-like cell infiltration. These results indicate that cisplatin and anti-CD133 CAR-T combination strategy can simultaneously target normal and stem cell-like gastric cancer cells to improve the treatment outcome.