Cripto-1 contributes to stemness in hepatocellular carcinoma by stabilizing Dishevelled-3 and activating Wnt/β-catenin pathway

Hepatocellular carcinoma: signaling pathways and therapeutic advances

Liver cancer represents a major global health concern, with projections indicating that the number of new cases could surpass 1 million annually by 2025. Hepatocellular carcinoma (HCC) constitutes around 90% of liver cancer cases and is primarily linked to factors incluidng aflatoxin, hepatitis B (HBV) and C (HCV), and metabolic disorders. There are no obvious symptoms in the early stage of HCC, which often leads to delays in diagnosis. Therefore, HCC patients usually present with tumors in advanced and incurable stages. Several signaling pathways are dis-regulated in HCC and cause uncontrolled cell propagation, metastasis, and recurrence of HCC. Beyond the frequently altered and therapeutically targeted receptor tyrosine kinase (RTK) pathways in HCC, pathways involved in cell differentiation, telomere regulation, epigenetic modification and stress response also provide therapeutic potential. Investigating the key signaling pathways and their inhibitors is pivotal for achieving therapeutic advancements in the management of HCC. At present, the primary therapeutic approaches for advanced HCC are tyrosine kinase inhibitors (TKI), immune checkpoint inhibitors (ICI), and combination regimens. New trials are investigating combination therapies involving ICIs and TKIs or anti-VEGF (endothelial growth factor) therapies, as well as combinations of two immunotherapy regimens. The outcomes of these trials are expected to revolutionize HCC management across all stages. Here, we provide here a comprehensive review of cellular signaling pathways, their therapeutic potential, evidence derived from late-stage clinical trials in HCC and discuss the concepts underlying earlier clinical trials, biomarker identification, and the development of more effective therapeutics for HCC.

Targeting Hepatic Cancer Stem Cells (CSCs) and Related Drug Resistance by Small Interfering RNA (siRNA)

Tumor recurrence after curative therapy and hepatocellular carcinoma (HCC) cells' resistance to conventional therapies is the reasons for the worse clinical results of HCC patients. A tiny population of cancer cells with a strong potential for self-renewal, differentiation, and tumorigenesis has been identified as cancer stem cells (CSCs). The discovery of CSC surface markers and the separation of CSC subpopulations from HCC cells have been made possible by recent developments in the study of hepatic (liver) CSCs. Hepatic CSC surface markers include epithelial cell adhesion molecules (EpCAM), CD133, CD90, CD13, CD44, OV-6, ALDH, and K19. CSCs have a significant influence on the development of cancer, invasiveness, self-renewal, metastasis, and drug resistance in HCC, and thus provide a therapeutic chance to treat HCC and avoid its recurrence. Therefore, it is essential to develop treatment approaches that specifically and effectively target hepatic stem cells. Given this, one potential treatment approach is to use particular small interfering RNA (siRNA) to target CSC, disrupting their behavior and microenvironment as well as changing their epigenetic state. The characteristics of CSCs in HCC are outlined in this study, along with new treatment approaches based on siRNA that may be used to target hepatic CSCs and overcome HCC resistance to traditional therapies.

Structural and Functional Insights into Dishevelled-Mediated Wnt Signaling

Dishevelled (DVL) proteins precisely control Wnt signaling pathways with many effectors. While substantial research has advanced our understanding of DVL's role in Wnt pathways, key questions regarding its regulatory mechanisms and interactions remain unresolved. Herein, we present the recent advances and perspectives on how DVL regulates signaling. The experimentally determined conserved domain structures of DVL in conjunction with AlphaFold-predicted structures are used to understand the DVL's role in Wnt signaling regulation. We also summarize the role of DVL in various diseases and provide insights into further directions for research on the DVL-mediated signaling mechanisms. These findings underscore the importance of DVL as a pharmaceutical target or biological marker in diseases, offering exciting potential for future biomedical applications.

Hepatocellular-Carcinoma-Derived Organoids: Innovation in Cancer Research

Hepatocellular carcinomas (HCCs) are highly heterogeneous malignancies. They are characterized by a peculiar tumor microenvironment and dense vascularization. The importance of signaling between immune cells, endothelial cells, and tumor cells leads to the difficult recapitulation of a reliable in vitro HCC model using the conventional two-dimensional cell cultures. The advent of three-dimensional organoid tumor technology has revolutionized our understanding of the pathogenesis and progression of several malignancies by faithfully replicating the original cancer genomic, epigenomic, and microenvironmental landscape. Organoids more closely mimic the in vivo environment and cell interactions, replicating factors such as the spatial organization of cell surface receptors and gene expression, and will probably become an important tool in the choice of therapies and the evaluation of tumor response to treatments. This review aimed to describe the ongoing and potential applications of organoids as an in vitro model for the study of HCC development, its interaction with the host's immunity, the analysis of drug sensitivity tests, and the current limits in this field.

Frizzled receptors (FZDs) in Wnt signaling: potential therapeutic targets for human cancers

Frizzled receptors (FZDs) are key contributors intrinsic to the Wnt signaling pathway, activation of FZDs triggering the Wnt signaling cascade is frequently observed in human tumors and intimately associated with an aggressive carcinoma phenotype. It has been shown that the abnormal expression of FZD receptors contributes to the manifestation of malignant characteristics in human tumors such as enhanced cell proliferation, metastasis, chemotherapy resistance as well as the acquisition of cancer stemness. Given the essential roles of FZD receptors in the Wnt signaling in human tumors, this review aims to consolidate the prevailing knowledge on the specific status of FZD receptors (FZD1-10) and elucidate their respective functions in tumor progression. Furthermore, we delineate the structural basis for binding of FZD and its co-receptors to Wnt, and provide a better theoretical foundation for subsequent studies on related mechanisms. Finally, we describe the existing biological classes of small molecule-based FZD inhibitors in detail in the hope that they can provide useful assistance for design and development of novel drug candidates targeted FZDs.

PCK1 attenuates tumor stemness via activating the Hippo signaling pathway in hepatocellular carcinoma

Liver cancer stem cells were found to rely on glycolysis as the preferred metabolic program. Phosphoenolpyruvate carboxylase 1 (PCK1), a gluconeogenic metabolic enzyme, is down-regulated in hepatocellular carcinoma and is closely related to poor prognosis. The oncogenesis and progression of tumors are closely related to cancer stem cells. It is not completely clear whether the PCK1 deficiency increases the stemness of hepatoma cells and promotes the oncogenesis of hepatocellular carcinoma. Herein, the results showed that PCK1 inhibited the self-renewal property of hepatoma cells, reduced the mRNA level of cancer stem cell markers, and inhibited tumorigenesis. Moreover, PCK1 increased the sensitivity of hepatocellular carcinoma cells to sorafenib. Furthermore, we found that PCK1 activated the Hippo pathway by enhancing the phosphorylation of YAP and inhibiting its nuclear translocation. Verteporfin reduced the stemness of hepatoma cells and promoted the pro-apoptotic effect of sorafenib. Thus, combined treatment with verteporfin and sorafenib may be a potential anti-tumor strategy in hepatocellular carcinoma.

GINS1 promotes ZEB1-mediated epithelial-mesenchymal transition and tumor metastasis via β-catenin signaling in hepatocellular carcinoma

GINS1 regulates DNA replication in the initiation and elongation phases and plays an important role in the progression of various malignant tumors. However, the role of GINS1 in hepatocellular carcinoma (HCC) remains largely unclear. In this study, we investigated the role and underlying mechanisms of GINS1 in contributing to HCC metastasis. We found that GINS1 was significantly upregulated in HCC tissues and cell lines, especially in HCC tissues with vascular invasion and HCC cell lines with highly metastatic properties. Additionally, high expression of GINS1 was positively correlated with the progressive clinical features of HCC patients, including tumor number (multiple), tumor size (>5 cm), advanced tumor stage, vascular invasion and early recurrence, suggesting that GINS1 upregulation was greatly involved in HCC metastasis. Moreover, Kaplan-Meier survival analysis revealed that high GINS1 expression predicted a poor prognosis. Both in vitro and in vivo, silencing of GINS1 inhibited proliferation, migration, invasion and metastasis, while overexpression of GINS1 induced opposite effects. Mechanistically, we found that ZEB1 was a crucial regulator of GINS1-induced epithelial-mesenchymal transition (EMT), and GINS1 promoted EMT and tumor metastasis through β-catenin signaling. Overall, the present study demonstrated that GINS1 promoted ZEB1-mediated EMT and tumor metastasis via β-catenin signaling in HCC.

Wnt/β-Catenin signaling pathway in hepatocellular carcinoma: pathogenic role and therapeutic target

Hepatocellular carcinoma (HCC) is the most common primary malignant liver tumor and one of the leading causes of cancer-related deaths worldwide. The Wnt/β-Catenin signaling pathway is a highly conserved pathway involved in several biological processes, including the improper regulation that leads to the tumorigenesis and progression of cancer. New studies have found that abnormal activation of the Wnt/β-Catenin signaling pathway is a major cause of HCC tumorigenesis, progression, and resistance to therapy. New perspectives and approaches to treating HCC will arise from understanding this pathway. This article offers a thorough analysis of the Wnt/β-Catenin signaling pathway's function and its therapeutic implications in HCC.

Natural products for combating multidrug resistance in cancer

Cancer cells frequently develop resistance to chemotherapeutic therapies and targeted drugs, which has been a significant challenge in cancer management. With the growing advances in technologies in isolation and identification of natural products, the potential of natural products in combating cancer multidrug resistance has received substantial attention. Importantly, natural products can impact multiple targets, which can be valuable in overcoming drug resistance from different perspectives. In the current review, we will describe the well-established mechanisms underlying multidrug resistance, and introduce natural products that could target these multidrug resistant mechanisms. Specifically, we will discuss natural compounds such as curcumin, resveratrol, baicalein, chrysin and more, and their potential roles in combating multidrug resistance. This review article aims to provide a systematic summary of recent advances of natural products in combating cancer drug resistance, and will provide rationales for novel drug discovery.

A signature based on circadian rhythm-associated genes for the evaluation of prognosis and the tumour microenvironment in HNSCC

The morbidity and mortality rates of head and neck squamous cell carcinoma (HNSCC) remain high worldwide. Therefore, there is an urgent need to identify a new prognostic biomarker to guide the personalized treatment of HNSCC patients. Increasing evidence suggests that circadian rhythm genes play an important role in the development and progression of cancer. We aimed to explore the value of circadian rhythm genes in predicting prognosis and guiding the treatment of HNSCC. We first obtained a list of circadian rhythm genes from previous research. The sequencing data were retrieved from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Finally, univariate Cox proportional hazard analysis, least absolute shrinkage and selection operator (LASSO) regression, and multivariate Cox proportional hazard analysis were performed to develop a prognostic signature (Circadian Rhythm-Related Gene Prognostic Index, CRRGPI) consisting of nine circadian rhythm genes. The signature exhibited good performance in predicting overall survival. Patients with low CRRGPI scores had lower metabolic activities and an active antitumour immunity ability. Additionally, a clinical cohort was used to further evaluate the ability of the CRRGPI to predict the efficacy of immune checkpoint inhibitors. In conclusion, the novel circadian rhythm-related gene signature can provide a precise prognostic evaluation with the potential capacity to guide individualized treatment regimens for HNSCC patients.

Phytochemicals as Potential Lead Molecules against Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent form of liver cancer, accounting for 85-90% of liver cancer cases and is a leading cause of cancer-related mortality worldwide. The major risk factors for HCC include hepatitis C and B viral infections, along with chronic liver diseases, such as cirrhosis, fibrosis, and non-alcoholic steatohepatitis associated with metabolic syndrome. Despite the advancements in modern medicine, there is a continuous rise in the annual global incidence rate of HCC, and it is estimated to reach >1 million cases by 2025. Emerging research in phytomedicine and chemotherapy has established the anti-cancer potential of phytochemicals, owing to their diverse biological activities. In this review, we report the major phytochemicals that have been explored in combating hepatocellular carcinoma and possess great potential to be used as an alternative or in conjunction with the existing HCC treatment modalities. An overview of the pre-clinical observations, mechanism of action and molecular targets of some of these phytochemicals is also incorporated.

TWIST1 activates cancer stem cell marker genes to promote epithelial-mesenchymal transition and tumorigenesis in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest cancers worldwide. Overexpression of EMT master transcription factors can promote differentiated cells to undergo cancer reprogramming processes and acquire a stem cell-like status.

METHODS

The KYSE-30 and YM-1 ESCC cell lines were transduced with retroviruses expressing TWIST1 or GFP and analyzed by quantitative reverse transcription PCR (qRT-PCR), chromatin immunoprecipitation (ChIP), and immunostaining to investigate the correlation between TWIST1 and stemness markers expression. Cells expressing TWIST1 were characterized for mRNA candidates by qRT-PCR and for protein candidates by Flow cytometry and Immunocytochemistry. TWIST1-ESCC cells were also evaluated for apoptosis and drug resistance.

RESULTS

Here we identify a role for TWIST1 in the establishment of ESCC cancer stem cell (CSC)-like phenotype, facilitating the transformation of non-CSCs to CSCs. We provide evidence that TWIST1 expression correlates with the expression of CSC markers in ESCC cell lines. ChIP assay results demonstrated that TWIST1 regulates CSC markers, including CD44, SALL4, NANOG, MEIS1, GDF3, and SOX2, through binding to the E-box sequences in their promoters. TWIST1 promoted EMT through E-cadherin downregulation and vimentin upregulation. Moreover, TWIST1 expression repressed apoptosis in ESCC cells through upregulation of Bcl-2 and downregulation of the Bax protein, and increased ABCG2 and ABCC4 transporters expression, which may lead to drug resistance.

CONCLUSIONS

These findings support a critical role for TWIST1 in CSC-like generation, EMT progression, and inhibition of apoptosis in ESCC. Thus, TWIST1 represents a therapeutic target for the suppression of esophageal cell transformation to CSCs and ESCC malignancy.

Circadian gene CSNK1D promoted the progression of hepatocellular carcinoma by activating Wnt/β-catenin pathway via stabilizing Dishevelled Segment Polarity Protein 3

PURPOSE

A variety of studies have connected circadian rhythm to the initiation and progression of hepatocellular carcinoma (HCC). The purpose of this study was to figure out about the circadian genes' profile characteristics, prognostic significance, and targeted values in HCC.

METHODS

The expression profiles and prognostic significance of circadian genes in the cancer genome atlas liver hepatocellular carcinoma (TCGA-LIHC) database were investigated using bioinformatics analysis. The expression features of Casein Kinase 1 Delta (CSNK1D), a robust signature gene, was further detected by immunohistochemistry, western blotting and Real-time quantitative PCR (RT-qPCR) in a local HCC cohort. The effect of CSNK1D on corresponding phenotypes of HCC cells was evaluated using Cell Counting Kit-8 (CCK8), flowcytometry, clone assay, Transwell assay, and xenograft assay. In addition, the underlying mechanisms of CSNK1D in the Wnt/β-catenin signaling were validated by multiple molecular experiments.

RESULTS

Abnormal expression of the Circadian genome was associated with the malignant clinicopathological characteristics of HCC patients. A 10 circadian gene-based signature with substantial prognostic significance was developed using Cox regression and least absolute shrinkage and selection operator (LASSO) analysis. Of them, CSNK1D, significantly elevated in a local HCC cohort, was chosen for further investigation. Silencing or overexpression of CSNK1D significantly reduced or increased proliferation, invasion, sorafenib resistance, xenograft development, and epithelial-mesenchymal transformation (EMT) of HCC cells, respectively. Mechanically, CSNK1D exacerbated the aggressiveness of HCC cells by activating Wnt/β-catenin signaling through interacting with Dishevelled Segment Polarity Protein 3 (DVL3).

CONCLUSIONS

The Circadian gene CSNK1D was found to contribute to HCC progression by boosting the Wnt/β-catenin pathway, hinting that it could be a prospective therapeutic target for HCC.

Understanding the role of Cripto-1 in cancer progression and therapeutic strategies

During the initial stages of gastrulation during embryonic differentiation and wound healing, Cripto-1 is a critical protein for human growth. The epithelial adhesion molecules' downregulation, the mesenchymal overexpression, and mobile proteins are important mechanisms by which Cripto-1 initiates epithelial to mesenchymal transition (EMT). As a result, the function of Cripto-1 for inducing EMT to increase cell migration is advantageous during embryogenesis; however, it is deleterious during the formation, growth, and malignant tumor metastasis. The majority of malignancies are reported to have elevated levels of Cripto-1. Cripto-1 can modify cancerous cells through its function in EMT, which enables these cells to migrate via the extracellular matrix, bloodstream, and lymphatic vessels, on their way for metastasizing to other organs. The goal of this review is to explain what role Cripto-1 plays in common cancers and to summarize how therapeutic strategies are used to interfere with this molecule to target cancers.

Wnt/β-Catenin Signaling as a Driver of Stemness and Metabolic Reprogramming in Hepatocellular Carcinoma

Simple Summary

Aberrant Wnt/β-catenin signaling has been reported to play crucial role in pathogenesis of hepatocellular carcinoma (HCC). In this review, we focus on the regulatory role of Wnt/β-catenin signaling in cancer stemness and metabolic reprogramming, which are two emerging hallmarks of cancer. Understanding the role of Wnt/β-catenin signaling in regulation of the above processes reveals novel therapeutic strategy against this deadly disease.

Abstract

Hepatocellular carcinoma (HCC) is a major cause of cancer death worldwide due to its high rates of tumor recurrence and metastasis. Aberrant Wnt/β-catenin signaling has been shown to play a significant role in HCC development, progression and clinical impact on tumor behavior. Accumulating evidence has revealed the critical involvement of Wnt/β-catenin signaling in driving cancer stemness and metabolic reprogramming, which are regarded as emerging cancer hallmarks. In this review, we summarize the regulatory mechanism of Wnt/β-catenin signaling and its role in HCC. Furthermore, we provide an update on the regulatory roles of Wnt/β-catenin signaling in metabolic reprogramming, cancer stemness and drug resistance in HCC. We also provide an update on preclinical and clinical studies targeting Wnt/β-catenin signaling alone or in combination with current therapies for effective cancer therapy. This review provides insights into the current opportunities and challenges of targeting this signaling pathway in HCC.

Mechanisms of resistance to tyrosine kinase inhibitors in liver cancer stem cells and potential therapeutic approaches

The administration of tyrosine kinase inhibitors (TKIs) for the treatment of advanced-stage patients is common in hepatocellular carcinoma (HCC). However, therapy resistance is often encountered, and its emergence eventually curtails long-term clinical benefits. Cancer stem cells (CSCs) are essential drivers of tumor recurrence and therapy resistance; thus, the elucidation of key hallmarks of resistance mechanisms of liver CSC-driven HCC may help improve patient outcomes and reduce relapse. The present review provides a comprehensive summary of the intrinsic and extrinsic mechanisms of TKI resistance in liver CSCs, which mediate treatment failure, and discusses potential strategies to overcome TKI resistance from a preclinical perspective.

LncRNA FGD5-AS1 enhances the proliferation and stemness of hepatocellular carcinoma cells through targeting miR-223 and regulating the expression of ECT2 and FAT1

AIM

Hepatocellular carcinoma (HCC) is common and causes many deaths worldwide. The aim of this study is to explore the mechanism by which long non-coding RNA FGD5-AS1 regulates HCC cell proliferation and stemness.

METHODS

Tumor and normal adjacent tissues were harvested from HCC patients. Real-time quantitative reverse transcription-PCR was applied to examine the expression of FGD5-AS1, miR-223, Epithelial cell transforming sequence 2 (ECT2) and FAT1. The protein levels of ECT2, FAT1, proliferating cell nuclear antigen (PCNA), OCT4, CD133 and CD90 were analyzed by western blot. The localization of FGD5-AS1 was examined by Fluorescence in situ hybridization. Cell proliferation was analyzed with CCK-8 and colony formation assays. Spheroid formation was used for analyzing cell stemness. Gene interaction was examined by RNA immunoprecipitation and luciferase activity assays. A subcutaneous xenograft mouse model was established to analyze HCC growth and stemness in vivo. Immunohistochemistry staining was used to analyze the expression PCNA and OCT4 in subcutaneous tumors.

RESULTS

FGD5-AS1 was upregulated in HCC and its high expression indicated poor prognosis of patients. High expression of FGD5-AS1 enhanced HCC cell proliferation and stemness. Knockdown of FGD5-AS1 restrained tumor growth and stemness in mice. FGD5-AS1 directly sponged miR-223 and promoted the expression of ECT2 and FAT1 in HCC. Both knockdown of miR-223 and overexpression of ECT2 and FAT1 reversed FGD5-AS1 silencing-mediated suppression of HCC cell proliferation and stemness.

CONCLUSION

FGD5-AS1 directly sponged miR-223 and promoted the expression of ECT2 and FAT1 in HCC, thus enhancing HCC cell proliferation and stemness. Our study identifies potential prognostic biomarkers and therapeutic targets for HCC.

New insights into antiangiogenic therapy resistance in cancer: Mechanisms and therapeutic aspects

Angiogenesis is a hallmark of cancer and is required for tumor growth and progression. Antiangiogenic therapy has been revolutionarily developing and was approved for the treatment of various types of cancer for nearly two decades, among which bevacizumab and sorafenib continue to be the two most frequently used antiangiogenic drugs. Although antiangiogenic therapy has brought substantial survival benefits to many cancer patients, resistance to antiangiogenic drugs frequently occurs during clinical treatment, leading to poor outcomes and treatment failure. Cumulative evidence has demonstrated that the intricate interplay among tumor cells, bone marrow-derived cells, and local stromal cells critically allows for tumor escape from antiangiogenic therapy. Currently, drug resistance has become the main challenge that hinders the therapeutic efficacies of antiangiogenic therapy. In this review, we describe and summarize the cellular and molecular mechanisms conferring tumor drug resistance to antiangiogenic therapy, which was predominantly associated with redundancy in angiogenic signaling molecules (e.g., VEGFs, GM-CSF, G-CSF, and IL17), alterations in biological processes of tumor cells (e.g., tumor invasiveness and metastasis, stemness, autophagy, metabolic reprogramming, vessel co-option, and vasculogenic mimicry), increased recruitment of bone marrow-derived cells (e.g., myeloid-derived suppressive cells, tumor-associated macrophages, and tumor-associated neutrophils), and changes in the biological functions and features of local stromal cells (e.g., pericytes, cancer-associated fibroblasts, and endothelial cells). We also review potential biomarkers to predict the response to antiangiogenic therapy in cancer patients, which mainly consist of imaging biomarkers, cellular and extracellular proteins, a certain type of bone marrow-derived cells, local stromal cell content (e.g., pericyte coverage) as well as serum or plasma biomarkers (e.g., non-coding RNAs). Finally, we highlight the recent advances in combination strategies with the aim of enhancing the response to antiangiogenic therapy in cancer patients and mouse models. This review introduces a comprehensive understanding of the mechanisms and biomarkers associated with the evasion of antiangiogenic therapy in cancer, providing an outlook for developing more effective approaches to promote the therapeutic efficacy of antiangiogenic therapy.

CRIPTO Is a Marker of Chemotherapy-Induced Stem Cell Expansion in Non-Small Cell Lung Cancer

Chemotherapy is the mainstay for the treatment of non-small cell lung cancer (NSCLC). However, NSCLC cells are either intrinsically chemoresistant or rapidly develop therapy resistance. Cancer stem cells (CSCs) are widely recognized as the cell population responsible for resistance to systemic therapies, but the molecular responses of CSCs to chemotherapeutic agents are largely unknown. We identified the embryonic protein CRIPTO in stem cell-enriched spheroid cultures of adenocarcinoma (AC) and squamous cell carcinoma (SCC) derived from NSCLC surgical specimens. The CRIPTO-positive population had increased clonogenic capacity and expression of stem cell-related factors. Stemness-related properties were also obtained with forced CRIPTO expression, whereas CRIPTO downregulation resulted in cell cycle blockade and CSCs death. Cell populations positive and negative for CRIPTO expression were interconvertible, and interfering with their reciprocal equilibrium resulted in altered homeostasis of cell expansion both in spheroid cultures and in tumor xenografts. Chemotherapy treatment of NSCLC cells resulted in reduction of cell number followed by increased CRIPTO expression and selective survival of CRIPTO-positive cells. In NSCLC tumor xenografts, chemotherapeutic agents induced partial cell death and tumor stabilization followed by CRIPTO overexpression and tumor progression. Altogether, these findings indicate CRIPTO as a marker of lung CSCs possibly implicated in cancer cell plasticity and post-chemotherapy tumor progression.

Lysine Interacts with Frizzled7 to Activate β-Catenin in Satellite Cell-Participated Skeletal Muscle Growth

This work provided an interesting finding of lysine (Lys) control on skeletal muscle growth besides protein synthesis. According to the isobaric tag for relative and absolute quantitation and molecular docking analyses, we found both in in vivo skeletal muscle and in vitro muscle satellite cells (MuSCs) that the frizzled7 (FZD7) expression level was positively correlated with Lys levels and this was consistent with the activation of the Wnt/β-catenin pathway. On the other hand, FZD7 inhibition suppressed the Lys-rescued Wnt/β-catenin pathway, FZD7 knockdown caused cell proliferation, and Wnt/β-catenin pathway restrictions could not be compensated for by Lys or Wnt3a. Furthermore, the combination between Lys and recombinant pig frizzled7 (rpFZD7) protein was confirmed by isothermal titration calorimetry. This finding displayed concrete evidence that Lys is not only a molecular block of protein synthesis but is also a ligand for FZD7 to activate β-catenin to stimulate MuSCs in promoting skeletal muscle growth.

β-Catenin signaling in hepatocellular carcinoma

Deregulated Wnt/β-catenin signaling is one of the main genetic alterations in human hepatocellular carcinoma (HCC). Comprehensive genomic analyses have revealed that gain-of-function mutation of CTNNB1, which encodes β-catenin, and loss-of-function mutation of AXIN1 occur in approximately 35% of human HCC samples. Human HCCs with activation of the Wnt/β-catenin pathway demonstrate unique gene expression patterns and pathological features. Activated Wnt/β-catenin synergizes with multiple signaling cascades to drive HCC formation, and it functions through its downstream effectors. Therefore, strategies targeting Wnt/β-catenin have been pursued as possible therapeutics against HCC. Here, we review the genetic alterations and oncogenic roles of aberrant Wnt/β-catenin signaling during hepatocarcinogenesis. In addition, we discuss the implication of this pathway in HCC diagnosis, classification, and personalized treatment.

Implications of Stemness Features in 1059 Hepatocellular Carcinoma Patients from Five Cohorts: Prognosis, Treatment Response, and Identification of Potential Compounds

Simple Summary

Cancer stemness has been reported to drive hepatocellular carcinoma (HCC) tumorigenesis and treatment resistance. However, comprehensive interpretations of transcriptomic stemness features in HCC patients have not been conducted in multiple cohorts. Our aim was to interpret clinical and therapeutic implications of transcriptional stemness features and explore potential compounds for HCC treatment. We found that transcriptional stemness indexes (mRNAsi) were independently associated with worse HCC prognosis. The HCC stemness risk model (HSRM) developed in this study significantly predicted prognosis and treatment response in various HCC cohorts. Analysis of two stemness subtypes suggested several liver-specific metabolic pathways, and mutations of TP53 and RB1 were associated with HCC transcriptional stemness. Moreover, we also identified potential compounds that target HCC transcriptional stemness. Our findings comprehensively characterized transcriptional stemness as a risk factor in HCC progression and treatment.

Abstract

Cancer stemness has been reported to drive hepatocellular carcinoma (HCC) tumorigenesis and treatment resistance. In this study, five HCC cohorts with 1059 patients were collected to calculate transcriptional stemness indexes (mRNAsi) by the one-class logistic regression machine learning algorithm. In the TCGA-LIHC cohort, we found mRNAsi was an independent prognostic factor, and 626 mRNAsi-related genes were identified by Spearman correlation analysis. The HCC stemness risk model (HSRM) was trained in the TCGA-LIHC cohort and significantly discriminated overall survival in four independent cohorts. HSRM was also significantly associated with transarterial chemoembolization treatment response and rapid tumor growth in HCC patients. Consensus clustering was conducted based on mRNAsi-related genes to divide 1059 patients into two stemness subtypes. On gene set variation analysis, samples of subtype I were found enriched with pathways such as DNA replication and cell cycle, while several liver-specific metabolic pathways were inhibited in these samples. Somatic mutation analysis revealed more frequent mutations of TP53 and RB1 in the subtype I samples. In silico analysis suggested topoisomerase, cyclin-dependent kinase, and histone deacetylase as potential targets to inhibit HCC stemness. In vitro assay showed two predicted compounds, Aminopurvalanol-a and NCH-51, effectively suppressed oncosphere formation and impaired viability of HCC cell lines, which may shed new light on HCC treatment.

TGF-β superfamily co-receptors in cancer

Transforming growth factor-β (TGF-β) superfamily signaling via their cognate receptors is frequently modified by TGF-β superfamily co-receptors. Signaling through SMAD-mediated pathways may be enhanced or depressed depending on the specific co-receptor and cell context. This dynamic effect on signaling is further modified by the release of many of the co-receptors from the membrane to generate soluble forms that are often antagonistic to the membrane-bound receptors. The co-receptors discussed here include TβRIII (betaglycan), endoglin, BAMBI, CD109, SCUBE proteins, neuropilins, Cripto-1, MuSK, and RGMs. Dysregulation of these co-receptors can lead to altered TGF-β superfamily signaling that contributes to the pathophysiology of many cancers through regulation of growth, metastatic potential, and the tumor microenvironment. Here we describe the role of several TGF-β superfamily co-receptors on TGF-β superfamily signaling and the impact on cellular and physiological functions with a particular focus on cancer, including a discussion on recent pharmacological advances and potential clinical applications targeting these co-receptors.

LncRNA LINC00460 takes a stimulating role on hepatocellular carcinoma stemness property

Abundant researches have stated that long noncoding RNAs (lncRNAs) are crucial molecules in intricate progression of various cancers in terms of their influence on cell stemness. However, no research has discussed the role of LINC00460 in the stemness of hepatocellular carcinoma (HCC). RT-qPCR and western blot were utilized to respectively examine the RNA and protein levels. Aldehyde dehydrogenase 1 (ALDH1) assays and sphere formation assay were performed to detect cell stemness property in vitro and in vivo subcutaneous xenograft tumor assay was performed to detect tumor growth. Interaction between RNAs was explored by luciferase reporter assays and RNA pull-down assays. Our results showed that LINC00460 was markedly over-expressed in HCC and silencing LINC00460 impaired cell stemness. Additionally, LINC00460 knockdown curbed proliferation, migration, invasion and epithelial-to-mesenchymal transition (EMT) and drove apoptosis of HCC cells. Further, LINC00460 bound to miR-503-5p and miR-654-3p to protect t-complex 1 (TCP1) from being inhibited by miR-503-5p/miR-654-3p. Rescue experiments confirmed the effect of LINC00460/miR-503-5p/miR-654-3p/TCP1 on HCC cell stemness. In conclusion, LINC00460 aggravated cell stemness in HCC via targeting miR-503-5p/miR-654-3p and TCP1, suggesting that LINC00460 may work as a potential signature for cell stemness in HCC.[Figure: see text].

Whence CRIPTO: The Reemergence of an Oncofetal Factor in 'Wounds' That Fail to Heal

There exists a set of factors termed oncofetal proteins that play key roles in ontogeny before they decline or disappear as the organism's tissues achieve homeostasis, only to then re-emerge in cancer. Although the unique therapeutic potential presented by such factors has been recognized for more than a century, their clinical utility has yet to be fully realized1. This review highlights the small signaling protein CRIPTO encoded by the tumor derived growth factor 1 (TDGF1/Tdgf1) gene, an oft cited oncofetal protein whose presence in the cancer literature as a tumor promoter, diagnostic marker and viable therapeutic target continues to grow. We touch lightly on features well established and well-reviewed since its discovery more than 30 years ago, including CRIPTO's early developmental roles and modulation of SMAD2/3 activation by a selected set of transforming growth factor β (TGF-β) family ligands. We predominantly focus instead on more recent and less well understood additions to the CRIPTO signaling repertoire, on its potential upstream regulators and on new conceptual ground for understanding its mode of action in the multicellular and often stressful contexts of neoplastic transformation and progression. We ask whence it re-emerges in cancer and where it 'hides' between the time of its fetal activity and its oncogenic reemergence. In this regard, we examine CRIPTO's restriction to rare cells in the adult, its potential for paracrine crosstalk, and its emerging role in inflammation and tissue regeneration-roles it may reprise in tumorigenesis, acting on subsets of tumor cells to foster cancer initiation and progression. We also consider critical gaps in knowledge and resources that stand between the recent, exciting momentum in the CRIPTO field and highly actionable CRIPTO manipulation for cancer therapy and beyond.

Liver-specific over-expression of Cripto-1 in transgenic mice promotes hepatocyte proliferation and deregulated expression of hepatocarcinogenesis-related genes and signaling pathways

In this study, we investigated the role of embryonic gene Cripto-1 (CR-1) in hepatocellular carcinoma (HCC) using hepatocyte-specific CR-1-overexpressing transgenic mice. The expression of truncated 1.7-kb CR-1 transcript (SF-CR-1) was significantly higher than the full-length 2.0-kb CR-1 transcript (FL-CR-1) in a majority of HCC tissues and cell lines. Moreover, CR-1 mRNA and protein levels were significantly higher in HCC tissues than adjacent normal liver tissues. Hepatocyte-specific over-expression of CR-1 in transgenic mice enhanced hepatocyte proliferation after 2/3 partial hepatectomy (2/3 PHx). CR-1 over-expression significantly increased in vivo xenograft tumor growth of HCC cells in nude mice and in vitro HCC cell proliferation, migration, and invasion. CR-1 over-expression in the transgenic mouse livers deregulated HCC-related signaling pathways such as AKT, Wnt/β-catenin, Stat3, MAPK/ERK, JNK, TGF-β and Notch, as well as expression of HCC-related genes such as CD5L, S100A8, S100A9, Timd4, Orm2, Orm3, PDK4, DMBT1, G0S2, Plk2, Plk3, Gsta1 and Gsta2. However, histological signs of precancerous lesions, hepatocyte dysplasia or HCC formation were not observed in the livers of 3-, 6- or 8-month-old hepatocyte-specific CR-1-overexpressing transgenic mice. These findings demonstrate that liver-specific CR-1 overexpression in transgenic mice deregulates signaling pathways and genes associated with HCC.

Cancer chemoprevention through Frizzled receptors and EMT

Frizzled (FZD) transmembrane receptors are well known for their role in β-catenin signaling and development and now understanding of their role in the context of cancer is growing. FZDs are often associated with the process of epithelial to mesenchymal transition (EMT) through β-catenin, but some also influence EMT through non-canonical pathways. With ten different FZDs, there is a wide range of activity from oncogenic to tumor suppressive depending on the tissue context. Alterations in FZD signaling can occur during development of premalignant lesions, supporting their potential as targets of chemoprevention agents. Agonizing or antagonizing FZD activity may affect EMT, which is a key process in lesion progression often targeted by chemoprevention agents. Recent studies identified a specific FZD as important for activity of an EMT inhibiting chemopreventive agent and other studies have highlighted the previously unrecognized potential for targeting small molecules to FZD receptors. This work demonstrates the value of investigating FZDs in chemoprevention and here we provide a review of FZDs in cancer EMT and their potential as chemoprevention targets.

New Insights into Cancer Targeted Therapy: Nodal and Cripto-1 as Attractive Candidates

The transforming growth factor beta (TGF-β) signaling is fundamental for correct embryonic development. However, alterations of this pathway have been correlated with oncogenesis, tumor progression and sustaining of cancer stem cells (CSCs). Cripto-1 (CR-1) and Nodal are two embryonic proteins involved in TGF-β signaling. Their expression is almost undetectable in terminally differentiated cells, but they are often re-expressed in tumor cells, especially in CSCs. Moreover, cancer cells that show high levels of CR-1 and/or Nodal display more aggressive phenotypes in vitro, while in vivo their expression correlates with a worse prognosis in several human cancers. The ability to target CSCs still represents an unmet medical need for the complete eradication of certain types of tumors. Given the prognostic role and the selective expression of CR-1 and Nodal on cancer cells, they represent archetypes for targeted therapy. The aim of this review is to clarify the role of CR-1 and Nodal in cancer stem populations and to summarize the current therapeutic strategy to target CSCs using monoclonal antibodies (mAbs) or other molecular tools to interfere with these two proteins.

Afatinib induces pro-survival autophagy and increases sensitivity to apoptosis in stem-like HNSCC cells

Afatinib, a second-generation tyrosine kinase inhibitor (TKI), exerts its antitumor effects in head and neck squamous cell carcinoma (HNSCC) by inducing intrinsic apoptosis through suppression of mTORC1. However, the detailed mechanism and biological significance of afatinib-induced autophagy in HNSCC remains unclear. In the present study, we demonstrated that afatinib induced mTORC1 suppression-mediated autophagy in HNSCC cells. Further mechanistic investigation revealed that afatinib stimulated REDD1-TSC1 signaling, giving rise to mTORC1 inactivation and subsequent autophagy. Moreover, ROS generation elicited by afatinib was responsible for the induction of the REDD1-TSC1-mTORC1 axis. In addition, pharmacological or genetic inhibition of autophagy sensitized HNSCC cells to afatinib-induced apoptosis, demonstrating that afatinib activated pro-survival autophagy in HNSCC cells. Importantly, in vitro and in vivo assays showed that afatinib caused enhanced apoptosis but weaker autophagy in stem-like HNSCC cells constructed by CDH1 knockdown. This suggested that blocking autophagy has the potential to serve as a promising strategy to target HNSCC stem cells. In conclusion, our findings suggested that the combination treatment with afatinib and autophagy inhibitors has the potential to eradicate HNSCC cells, especially cancer stem cells in clinical therapy.

An Immunohistochemical Study of β-catenin Expression and Immune Cell Population in Metastatic Carcinoma to the Liver

The liver is the commonest site of cancer metastasis. In this study, we asked whether the immune tumor microenvironment in liver metastases was governed by the β-catenin activation status of the tumor. To this end, we analyzed CD8 and FoxP3 immunohistochemical expression against β-catenin expression status of the tumor in a cohort of 52 liver samples with metastatic carcinoma. The results showed that colorectal primary constituted the largest proportion of metastatic carcinoma showing β-catenin overexpression. Intra-tumoral CD8 count was lower and FoxP3 count was higher when compared with the non-tumoral liver parenchyma. β-catenin overexpression was associated with a lower CD8 count in the tumor region (p = 0.003). In summary, our findings are in support of an altered immune tumor microenvironment vs. the non-tumor liver tissues in the metastatic site. Suppression of CD8 count was associated with activated Wnt/β-catenin signaling in the metastatic tumor.

A Comprehensive Prognostic and Immunological Analysis of a New Three-Gene Signature in Hepatocellular Carcinoma

There are few reports on the role of genes associated with the mRNA expression-based stemness index (mRNAsi) in the prognosis and immune regulation of hepatocellular carcinoma (HCC). This study is aimed at analyzing the expression profile and prognostic significance of a new mRNAsi-based three-gene signature in HCC. This three-gene signature was identified by analyzing mRNAsi data from the Cancer Genome Atlas (TCGA) HCC dataset. The prognostic value of the risk score based on the three-gene signature was evaluated by Cox regression and Kaplan-Meier analysis and then verified in the International Cancer Genome Consortium (ICGC) database. Meanwhile, the correlations between the risk score and immune cell infiltration patterns, microsatellite instability (MSI), tumor mutation burden (TMB), immune checkpoint molecules, hypoxia-related genes, immunotherapy response, and compounds targeting the gene signature were explored, respectively. The results showed that compared with normal liver tissues, the mRNAsi score of HCC tissues was significantly increased. PTDSS2, MRPL9, and SOCS were the genes most related to mRNAsi in HCC tissues. Survival analysis results suggested the risk score based on the three-gene signature was an independent predictor of the prognosis for patients with HCC. The nomogram combining the risk score and pathological stage showed a good predictive ability for the overall survival of patients with HCC patients. Meanwhile, the risk score was significantly related to immune cell infiltration patterns, MSI, TMB, several immune checkpoint molecules, and hypoxia-related genes. In addition, the risk score was associated with the immunotherapy response, and fifteen potential therapeutic drugs targeting the three-gene signature were identified. Therefore, we propose to use this three-gene signature including PTDSS2, MRPL9, and SOCS as a potential prognostic biomarker for HCC.

The inhibition of ABCB1/MDR1 or ABCG2/BCRP enables doxorubicin to eliminate liver cancer stem cells

Two ATP-binding cassette transporters, ABCB1/MDR1 and ABCG2/BCRP, are considered the most critical determinants for chemoresistance in hepatocellular carcinoma. However, their roles in the chemoresistance in liver cancer stem cells remain elusive. Here we explored the role of inhibition of MDR1 or ABCG2 in sensitizing liver cancer stem cells to doxorubicin, the most frequently used chemotherapeutic agent in treating liver cancer. We show that the inhibition of MDR1 or ABCG2 in Huh7 and PLC/PRF/5 cells using either pharmacological inhibitors or RNAi resulted in the elevated level of intracellular concentration of doxorubicin and the accompanied increased apoptosis as determined by confocal microscopy, high-performance liquid chromatography, flow cytometry, and annexin V assay. Notably, the inhibition of MDR1 or ABCG2 led to the reversal of the chemoresistance, as evident from the enhanced death of the chemoresistant liver cancer stem cells in tumorsphere-forming assays. Thus, the elevation of effective intracellular concentration of doxorubicin via the inhibition of MDR1 or ABCG2 represents a promising future strategy that transforms doxorubicin from a traditional chemotherapy agent into a robust killer of liver cancer stem cells for patients undergoing transarterial chemoembolization.

Cripto-1 as a Potential Target of Cancer Stem Cells for Immunotherapy

Simple Summary

Cancer immunotherapy is gaining attention as a potential fourth treatment following surgery, chemotherapy, and radiation therapy. Cancer stem cells have recently been recognized and validated as a key target for cancer treatment. Cripto-1, which is a GPI-anchored membrane-bound protein that functions as a co-receptor of Nodal, is a marker of cancer stem cells. Since Nodal is a member of the TGF-β family, which performs an important role in stem cells and cancer stem cells, the inhibition of Cripto-1 could be a strategy by which to block Nodal signaling and thereby suppress cancer stem cells. We propose that Cripto-1 may be a novel target for cancer immunotherapy.

Abstract

The immune system has been found to be suppressed in cancer patients. Cancer cells are extremely resistant to chemotherapeutic drugs, conventional immunotherapy, or cancer antigen vaccine therapy. Cancer immunotherapy, which is mainly based on immune checkpoint inhibitors, such as those for PD-1, PD-L1, and CTLA4, is an effective treatment method. However, no immunotherapeutic target has been found that retains validity in the face of tumor diversity. The transforming growth factor (TGF)-β cytokine family possesses broad biological activity and is involved in the induction and/or transdifferentiation of helper T cells, which are important in immunotherapy. Nodal is a member of the TGF-β family playing important roles in tissue stem cells and cancer stem cells (CSCs), interacting with the co-receptor Cripto-1, as well as with Activin type IB (Alk4) and Activin typeIIreceptors, and maintaining stemness and Notch and Wnt/β-catenin signaling in CSCs. In recent years, it has been reported that Cripto-1 could be a potential therapeutic target in CSCs. Here, we review the accumulated literature on the molecular mechanisms by which Cripto-1 functions in CSCs and discuss the potential of Cripto-1 as an immunotherapeutic target in CSCs.

Microvesicles - promising tiny players' of cancer stem cells targeted liver cancer treatments: The interesting interactions and therapeutic aspects

Liver cancer is one of the most malignant cancers worldwide with poor prognosis. Intracellular mediators like microvesicles (MVs) and cancer stem cells (CSCs) are considered as potential candidates in liver cancer progression. CSCs receive stimuli from the tumor microenvironment to initiate tumor formation in which it's secreted MVs play a noteworthy role. The phenotypic conversion of tumor cells during epithelial-to-mesenchymal transition (EMT) is a key step in tumor invasion and metastasis which indicates that the diverse cell populations within the primary tumor are in a dynamic balance and can be regulated by cell to cell communication via secreted microvesicles. Thus, in this review, we aim to highlight the evidences that suggest CSCs are crucial for liver cancer development where the microvesicles plays an important part in the maintenance of its stemness properties. In addition, we summarize the existing evidences that support the concept of microvesicles, the tiny particles have a big role behind the rare immortal CSCs which controls the tumor initiation, propagation and metastasis in liver cancer. Identifying interactions between CSCs and microvesicles may offer new insights into precise anti-cancer therapies in the future.

BEZ235 Increases the Sensitivity of Hepatocellular Carcinoma to Sorafenib by Inhibiting PI3K/AKT/mTOR and Inducing Autophagy

Acquired resistance of hepatocellular carcinoma (HCC) to sorafenib (SFB) is the main reason for the failure of SFB treatment of the cancer. Abnormal activation of the PI3K/AKT/mTOR pathway is important in the acquired resistance of SFB. Therefore, we investigated whether BEZ235 (BEZ) could reverse acquired sorafenib resistance by targeting the PI3K/mTOR pathway. A sorafenib-resistant HCC cell line Huh7^R was established. MTT assay, clone formation assay, flow cytometry, and immunofluorescence were used to analyze the effects of BEZ235 alone or combined with sorafenib on cell proliferation, cell cycle, apoptosis, and autophagy of Huh7 and Huh7^R cells. The antitumor effect was evaluated in animal models of Huh7^R xenografts in vivo. Western blot was used to detect protein levels of the PI3K/AKT/mTOR pathway and related effector molecules. In vitro results showed that the Huh7^R had a stronger proliferation ability and antiapoptosis effect than did Huh7, and sorafenib had no inhibitory effect on Huh7^R. SFB + BEZ inhibited the activation of the PI3K/AKT/mTOR pathway caused by sorafenib. Moreover, SFB + BEZ inhibited the proliferation and cloning ability, blocked the cell cycle in the G0/G1 phase, and promoted apoptosis in the two cell lines. The autophagy level in Huh7^R cells was higher than in Huh7 cells, and BEZ or SFB + BEZ further promoted autophagy in the two cell lines. In vivo, SFB + BEZ inhibited tumor growth by inducing apoptosis and autophagy. We concluded that BEZ235 enhanced the sensitivity of sorafenib through suppressing the PI3K/AKT/mTOR pathway and inducing autophagy. These observations may provide the experimental basis for sorafenib combined with BEZ235 in trial treatment of HCC.

The interplay of UBE2T and Mule in regulating Wnt/β-catenin activation to promote hepatocellular carcinoma progression

Emerging evidence indicates the role of cancer stem cells (CSCs) in tumor relapse and therapeutic resistance in patients with hepatocellular carcinoma (HCC). To identify novel targets against liver CSCs, an integrative analysis of publicly available datasets involving HCC clinical and stemness-related data was employed to select genes that play crucial roles in HCC via regulation of liver CSCs. We revealed an enrichment of an interstrand cross-link repair pathway, in which ubiquitin-conjugating enzyme E2 T (UBE2T) was the most significantly upregulated. Consistently, our data showed that UBE2T was upregulated in enriched liver CSC populations. Clinically, UBE2T overexpression in HCC was further confirmed at mRNA and protein levels and was correlated with advanced tumor stage and poor patient survival. UBE2T was found to be critically involved in the regulation of liver CSCs, as evidenced by increases in self-renewal, drug resistance, tumorigenicity, and metastasis abilities. Mule, an E3 ubiquitin ligase, was identified to be the direct protein binding partner of UBE2T. Rather than the canonical role of acting as a mediator to transfer ubiquitin to E3 ligases, UBE2T is surprisingly able to physically bind and regulate the protein expression of Mule via ubiquitination. Mule was found to directly degrade β-catenin protein, and UBE2T was found to mediate liver CSC functions through direct regulation of Mule-mediated β-catenin degradation; this effect was abolished when the E2 activity of UBE2T was impaired. In conclusion, we revealed a novel UBE2T/Mule/β-catenin signaling cascade that is involved in the regulation of liver CSCs, which provides an attractive potential therapeutic target for HCC.

MiR-590-5p regulates cell proliferation, apoptosis, migration and invasion in oral squamous cell carcinoma by targeting RECK

OBJECTIVE

To discover the role of miR-590-5p in oral squamous cell carcinoma (OSCC) progression and the corresponding mechanism via the targeting RECK.

METHODS

OSCC (n=85) and normal oral tissues (n=60) were collected to quantify the miR-590-5p expression by using qRT-PCR. Then SCC-15 and OEC-M1 cells were selected and divided into Mock, inhibitor NC, miR-590-5p inhibitor, si-RECK and miR-590-5p inhibitor + si-RECK groups. Dual-luciferase reporter gene assay was used to verify if miR-590-5p could target RECK. The biological behaviors of OSCC cells were evaluated by MTT, Wound-healing, Transwell and Flow cytometry. The expression of miR-590-5p and RECK was measured by qRT-PCR and Western blotting , respectively.

RESULTS

Overexpression of miR-590-5p was found in OSCC tissues. The expression of miR-590-5p was significantly associated with the clinical TNM stage, differentiation degree, and lymph node metastasis of OSCC. RECK was identified as a direct target of miR-590-5p. Compared with the Mock group, cells in the miR-590-5p inhibitor group were decreased in terms of proliferation, invasion, and migration, and increased in cell apoptosis, accompanied by down-regulated miR-590-5p, Bcl-2/Bax and MMP-9, and up-regulated RECK. By contrast, si-RECK group presented completely opposite changes, and si-RECK reversed the inhibitory effect of miR-590-5p inhibitor on the OSCC cell growth.

CONCLUSION

MiR-590-5p expression was obviously increased in OSCC, and inhibiting miR-590-5p enhanced the expression of its target gene RECK, thereby suppressing proliferation, migration and invasion of OSCC cells and promoting apoptosis of OSCC cells.

TRIM32/USP11 Balances ARID1A Stability and the Oncogenic/Tumor-Suppressive Status of Squamous Cell Carcinoma

Squamous cell carcinoma (SCC) is an aggressive epithelial malignancy, yet the molecular mechanisms underlying SCC development are elusive. ARID1A is frequently mutated in various cancer types, but both mutation rates and expression levels of ARID1A are ubiquitously low in SCCs. Here, we reveal that excessive protein degradation mediated by the ubiquitin-proteasome system (UPS) contributes to the loss of ARID1A expression in SCC. We identify that the E3 ligase TRIM32 and the deubiquitinase USP11 play key roles in controlling ARID1A stability. TRIM32 depletion inhibits SCC cell proliferation, metastasis, and chemoresistance by stabilizing ARID1A, while USP11 depletion promotes SCC development by promoting ARID1A degradation. We show that syndecan-2 (SDC2) is the downstream target of both ARID1A and USP11 and that SDC2 depletion abolishes the oncogenic function of ARID1A loss. In summary, our data reveal UPS-mediated protein degradation as a mechanism underlying ARID1A loss and propose an important role for the TRIM32/USP11-ARID1A-SDC2 axis in SCC.

Tumor Suppressor Gene XEDAR Promotes Differentiation and Suppresses Proliferation and Migration of Gastric Cancer Cells Through Upregulating the RELA/LXRα Axis and Deactivating the Wnt/β-Catenin Pathway

X-linked ectodermal dysplasia receptor (XEDAR) is a new member of the tumor necrosis factor receptor (TNFR) family that induces cell death. The purpose of this study is to determine the tumor-suppressive potential of XEDAR in the development and differentiation of gastric cancer (GC). XEDAR levels were analyzed in human GC tissues and adjacent normal tissues by immunohistochemistry (IHC), quantitative real-time reverse transcription PCR (RT-qPCR), and Western blot analysis. We found that XEDAR expression was significantly downregulated in GC tissues and further decreased in low differentiated GC tissues. Overexpression of XEDAR in MKN45 and MGC803 cells suppressed the ability of cell proliferation and migration, whereas silencing XEDAR showed the opposite effect. Additionally, XEDAR silencing resulted in the upregulation of the differentiation molecular markers β-catenin, CD44 and Cyclin D1 at the protein levels, whereas XEDAR overexpression showed the opposite effect. Notably, XEDAR positively regulated the expression of liver X receptor alpha (LXRα) through upregulating the RELA gene that was characterized as a transcription factor of LXRα in this study. Inhibition of LXRα by GSK2033 or activation of the Wnt/β-catenin pathway by Wnt agonist 1 impaired the effect of XEDAR overexpression on differentiation of MKN45 cells. Moreover, inhibition of RELA mediated by siRNA could promote cell proliferation/migration and rescue the effect of XEDAR overexpression on cell behaviors and expression of genes. Subsequently, overexpression of XEDAR suppressed the growth of GC cells in vivo. Taken together, our findings showed that XEDAR could promote differentiation and suppress proliferation and invasion of GC cells.

CRIPTO antagonist ALK4L75A-Fc inhibits breast cancer cell plasticity and adaptation to stress

BACKGROUND

CRIPTO is a multi-functional signaling protein that promotes stemness and oncogenesis. We previously developed a CRIPTO antagonist, ALK4L75A-Fc, and showed that it causes loss of the stem cell phenotype in normal mammary epithelia suggesting it may similarly inhibit CRIPTO-dependent plasticity in breast cancer cells.

METHODS

We focused on two triple negative breast cancer cell lines (MDA-MB-231 and MDA-MB-468) to measure the effects of ALK4L75A-Fc on cancer cell behavior under nutrient deprivation and endoplasmic reticulum stress. We characterized the proliferation and migration of these cells in vitro using time-lapse microscopy and characterized stress-dependent changes in the levels and distribution of CRIPTO signaling mediators and cancer stem cell markers. We also assessed the effects of ALK4L75A-Fc on proliferation, EMT, and stem cell markers in vivo as well as on tumor growth and metastasis using inducible lentiviral delivery or systemic administration of purified ALK4L75A-Fc, which represents a candidate therapeutic approach.

RESULTS

ALK4L75A-Fc inhibited adaptive responses of breast cancer cells under conditions of nutrient and ER stress and reduced their proliferation, migration, clonogenicity, and expression of EMT and cancer stem cell markers. ALK4L75A-Fc also inhibited proliferation of human breast cancer cells in stressed tumor microenvironments in xenografts and reduced both primary tumor size and metastatic burden.

CONCLUSIONS

Cancer cell adaptation to stresses such as nutrient deprivation, hypoxia, and chemotherapy can critically contribute to dormancy, metastasis, therapy resistance, and recurrence. Identifying mechanisms that govern cellular adaptation, plasticity, and the emergence of stem-like cancer cells may be key to effective anticancer therapies. Results presented here indicate that targeting CRIPTO with ALK4L75A-Fc may have potential as such a therapy since it inhibits breast cancer cell adaptation to microenvironmental challenges and associated stem-like and EMT phenotypes.

Glycochenodeoxycholic acid induces stemness and chemoresistance via the STAT3 signaling pathway in hepatocellular carcinoma cells

The poor prognosis of hepatocellular carcinoma (HCC) is primarily attributed to its high frequency of recurrence and resistance to chemotherapy. Epithelial-to-mesenchymal transition (EMT) and the acquisition of cancer stem cells (CSCs) are the fundamental drivers of chemoresistance in HCC. Glycochenodeoxycholic acid (GCDC), a component of bile acid (BA), has been reported to induce necrosis in primary human hepatocytes. In the present work, we investigated the function of GCDC in HCC chemoresistance. We found that GCDC promoted chemoresistance in HCC cells by down-regulating and up-regulating the expression of apoptotic and anti-apoptotic genes, respectively. Furthermore, GCDC induced the EMT phenotype and stemness in HCC cells and activated the STAT3 signaling pathway. These findings reveal that GCDC promotes chemoresistance in HCC by inducing stemness via the STAT3 pathway and could be a potential target in HCC chemotherapy.

Anti-tumour effects of PIM kinase inhibition on progression and chemoresistance of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a biologically aggressive cancer. Targeted therapy is in need to tackle challenges in the treatment perspective. A growing body of evidence suggests a promising role of pharmacological inhibition of PIM (proviral integration site for Moloney murine leukaemia virus) kinase in some human haematological and solid cancers. Yet to date, the potential application of PIM inhibitors in HCC is still largely unexplored. In the present study we investigated the pre-clinical efficacy of PIM inhibition as a therapeutic approach in HCC. Effects of PIM inhibitors on cell proliferation, migration, invasion, chemosensitivity, and self-renewal were examined in vitro. The effects of PIM inhibitors on tumour growth and chemoresistance in vivo were studied using xenograft mouse models. Potential downstream molecular mechanisms were elucidated by RNA sequencing (RNA-seq) of tumour tissues harvested from animal models. Our findings demonstrate that PIM inhibitors SGI-1776 and PIM447 reduced HCC proliferation, metastatic potential, and self-renewal in vitro. Results from in vivo experiments supported the role of PIM inhibition in suppressing of tumour growth and increasing chemosensitivity of HCC toward cisplatin and doxorubicin, the two commonly used chemotherapeutic agents in trans-arterial chemoembolisation (TACE) for HCC. RNA-seq analysis revealed downregulation of the MAPK/ERK pathway upon PIM inhibition in HCC cells. In addition, LOXL2 and ICAM1 were identified as potential downstream effectors. Taken together, PIM inhibitors demonstrated remarkable anti-tumourigenic effects in HCC in vitro and in vivo. PIM kinase inhibition is a potential approach to be exploited in formulating adjuvant therapy for HCC patients of different disease stages. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Beneficial effects of Cripto-1 for transarterial chemoembolization in hepatocellular carcinoma

Cripto-1 may act as an independent predictor for prognosis in hepatocellular carcinoma (HCC). However, the function of Cripto-1 in HCC cells and its response to postoperative transarterial chemoembolization (TACE) in HCC patients remains unclearly. Up-regulated Cripto-1 expression boosted the ability of cell proliferation, migration and invasion in HCC cells in vitro. While opposite results were observed in HCC cells with down-regulated Cripto-1 expression. Cripto-1 expression was correlated with epithelial-mesenchymal transition (EMT) relevant biomarkers. Furthermore, in high Cripto-1 expression patients, those with adjuvant TACE had favorable TTR and OS times. On contrary, adjuvant TACE may promote tumor recurrence but had no influence on OS time in patients with low Cripto-1 expression. In different subgroups of vascular invasion, larger tumor size or liver cirrhosis, patients with adjuvant TACE had longer TTR and OS times than those without TACE in patients with high Cripto-1 expression, while they could not obtain benefits from adjuvant TACE in patients with low-expressed Cripto-1 expression. In conclusion, Cripto-1 may be a potential prognostic factor in predicting outcome of HCC patients with TACE therapy, and combined with Cripto-1 and tumor features may be helpful to stratify patients with respect to prognosis and response to adjuvant TACE.

A Multidisciplinary Review of the Roles of Cripto in the Scientific Literature Through a Bibliometric Analysis of its Biological Roles

Cripto is a small glycosylphosphatidylinisitol (GPI)-anchored and secreted oncofetal protein that plays important roles in regulating normal physiological processes, including stem cell differentiation, embryonal development, and tissue growth and remodeling, as well as pathological processes such as tumor initiation and progression. Cripto functions as a co-receptor for TGF-β ligands such as Nodal, GDF1, and GDF3. Soluble and secreted forms of Cripto also exhibit growth factor-like activity and activate SRC/MAPK/PI3K/AKT pathways. Glucose-Regulated Protein 78 kDa (GRP78) binds Cripto at the cell surface and has been shown to be required for Cripto signaling via both TGF-β and SRC/MAPK/PI3K/AKT pathways. To provide a comprehensive overview of the scientific literature related to Cripto, we performed, for the first time, a bibliometric analysis of the biological roles of Cripto as reported in the scientific literature covering the last 10 years. We present different fields of knowledge in comprehensive areas of research on Cripto, ranging from basic to translational research, using a keyword-driven approach. Our ultimate aim is to aid the scientific community in conducting targeted research by identifying areas where research has been conducted so far and, perhaps more importantly, where critical knowledge is still missing.

Casticin inhibits stemness of hepatocellular carcinoma cells via disrupting the reciprocal negative regulation between DNMT1 and miR-148a-3p

Casticin (CAS) is a polymethyl flavonoid from Fructus viticis and has multiple pharmacological activities, including anticancer. However, whether the molecular mechanism underlying CAS represses stemness characteristics in hepatocellular carcinoma (HCC) cells involves intervention in the reciprocal negative regulation between DNA methyltransferase 1 (DNMT1) and miR-148a-3p has not yet been reported. In this study, the effect of CAS on stemness characteristics of HCC cells and its mechanism were investigated. Results showed that CAS selectively reduced the viabilities of HCC cells but not L02 cells, as determined by CCK-8 assay. Importantly, the sub-cytotoxic concentrations of CAS could inhibit the stemness characteristics in HCC cells, as demonstrated by the expression of stemness biomarkers (CD44, EpCAM, Bmi1, Nanog, and Oct4), sphere forming assay, RT-qPCR, and Western blotting. In addition, CAS repressed DNMT1 activity and expression and increased miR-148a-3p. The effect of CAS on stemness characteristics was abolished by stable DNMT1 overexpression. MiR-148a-3p overexpression enhanced the reduction of CAS on stemness characteristics. DNMT1 overexpression promoted miR-148a-3p promoter hypermethylation as detected by methylation-specific PCR (MSP), which repressed its expression. Conversely, miR-148a-3p repressed DNMT1 expression by specific site binding to 3'-UTR of DNMT1 mRNA, as determined by luciferase assay. Moreover, the combination of CAS and agomir-148a-3p had robust effects on tumor suppression as compared to the sole activity of either molecule in nude mouse xenograft experiments in vivo. The findings suggested that CAS could inhibit stemness characteristics in HCC cells by interruption of the reciprocal negative regulation between DNMT1 and miR-148a-3p.

Cancer stemness in hepatocellular carcinoma: mechanisms and translational potential

Cancer stemness, referring to the stem-cell-like phenotype of cancer cells, has been recognised to play important roles in different aspects of hepatocarcinogenesis. A number of well-established cell-surface markers already exist for liver cancer stem cells, with potential new markers of liver cancer stem cells being identified. Both genetic and epigenetic factors that affect various signalling pathways are known to contribute to cancer stemness. In addition, the tumour microenvironment—both physical and cellular—is known to play an important role in regulating cancer stemness, and the potential interaction between cancer stem cells and their microenvironment has provided insight into the regulation of the tumour-initiating ability as well as the cellular plasticity of liver CSCs. Potential specific therapeutic targeting of liver cancer stemness is also discussed. With increased knowledge, effective druggable targets might be identified, with the aim of improving treatment outcome by reducing chemoresistance.

Prognostic value of cripto-1 expression in non-small-cell lung cancer patients: a systematic review and meta-analysis

Aim: This systematic review and meta-analysis aimed to analyze the association between cripto-1 expression and prognosis as well as clinicopathological features of non-small-cell lung cancer (NSCLC) patients. Methods: The electronic databases for all articles about NSCLC and cripto-1 expression were searched. Results: Twelve articles were enrolled in this meta-analysis (3130 samples). In NSCLC patients, cripto-1 was expressed higher than in normal tissues. Cripto-1 expression was closely correlated with lymph node metastasis, histological differentiation and advanced clinical stage of NSCLC patients, but not related to smoking, age and gender. Pooled hazard ratios found that high cripto-1 expression had poor overall survival and progression-free survival. Conclusion: Cripto-1 could serve as a novel biomarker for predicting poor prognosis in NSCLC patients.

Cripto-1 localizes to dynamic and shed filopodia associated with cellular migration in glioblastoma cells

Cripto-1 is a protein participating in tissue orientation during embryogenesis but has also been implicated in a wide variety of cancers, such as colon, lung and breast cancer. Cripto-1 plays a role in the regulation of different pathways, including TGF-β/Smad and Wnt/β-catenin, which are highly associated with cell migration both during embryonal development and cancer progression. Little is known about the detailed subcellular localization of cripto-1 and how it participates in the directional movement of cells. In this study, the subcellular localization of cripto-1 in glioblastoma cells was investigated in vitro with high-resolution microscopy techniques. Cripto-1 was found to be localized to dynamic and shed filopodia and transported between cells through tunneling nanotubes. Our results connect the refined subcellular localization of cripto-1 to its functions in cellular orientation and migration.