Regulation of a TGF-β1-CD147 self-sustaining network in the differentiation plasticity of hepatocellular carcinoma cells

Signaling pathways in liver cancer: pathogenesis and targeted therapy

Liver cancer remains one of the most prevalent malignancies worldwide with high incidence and mortality rates. Due to its subtle onset, liver cancer is commonly diagnosed at a late stage when surgical interventions are no longer feasible. This situation highlights the critical role of systemic treatments, including targeted therapies, in bettering patient outcomes. Despite numerous studies on the mechanisms underlying liver cancer, tyrosine kinase inhibitors (TKIs) are the only widely used clinical inhibitors, represented by sorafenib, whose clinical application is greatly limited by the phenomenon of drug resistance. Here we show an in-depth discussion of the signaling pathways frequently implicated in liver cancer pathogenesis and the inhibitors targeting these pathways under investigation or already in use in the management of advanced liver cancer. We elucidate the oncogenic roles of these pathways in liver cancer especially hepatocellular carcinoma (HCC), as well as the current state of research on inhibitors respectively. Given that TKIs represent the sole class of targeted therapeutics for liver cancer employed in clinical practice, we have particularly focused on TKIs and the mechanisms of the commonly encountered phenomena of its resistance during HCC treatment. This necessitates the imperative development of innovative targeted strategies and the urgency of overcoming the existing limitations. This review endeavors to shed light on the utilization of targeted therapy in advanced liver cancer, with a vision to improve the unsatisfactory prognostic outlook for those patients.

Autophagy and the unfolded protein response shape the non-alcoholic fatty liver landscape: decoding the labyrinth

The incidence of nonalcoholic fatty liver disease (NAFLD) is on the rise, mirroring a global surge in diabetes and metabolic syndrome, as its major leading causes. NAFLD represents a spectrum of liver disorders, ranging from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), which can potentially progress to cirrhosis and hepatocellular carcinoma (HCC). Mechanistically, we know the unfolded protein response (UPR) as a protective cellular mechanism, being triggered under circumstances of endoplasmic reticulum (ER) stress. The hepatic UPR is turned on in a broad spectrum of liver diseases, including NAFLD. Recent data also defines molecular mechanisms that may underlie the existing correlation between UPR activation and NAFLD. More interestingly, subsequent studies have demonstrated an additional mechanism, i.e. autophagy, to be involved in hepatic steatosis, and thus NAFLD pathogenesis, principally by regulating the insulin sensitivity, hepatocellular injury, innate immunity, fibrosis, and carcinogenesis. All these findings suggest possible mechanistic roles for autophagy in the progression of NAFLD and its complications. Both UPR and autophagy are dynamic and interconnected fluxes that act as protective responses to minimize the harmful effects of hepatic lipid accumulation, as well as the ER stress during NAFLD. The functions of UPR and autophagy in the liver, together with findings of decreased hepatic autophagy in correlation with conditions that predispose to NAFLD, such as obesity and aging, suggest that autophagy and UPR, alone or combined, may be novel therapeutic targets against the disease. In this review, we discuss the current evidence on the interplay between autophagy and the UPR in connection to the NAFLD pathogenesis.

EMMPRIN promotes spheroid organization and metastatic formation: comparison between monolayers and spheroids of CT26 colon carcinoma cells

Background

In vitro studies often use two-dimensional (2D) monolayers, but 3D cell organization, such as in spheroids, better mimics the complexity of solid tumors. To metastasize, cancer cells undergo the process of epithelial-to-mesenchymal transition (EMT) to become more invasive and pro-angiogenic, with expression of both epithelial and mesenchymal markers.

Aims

We asked whether EMMPRIN/CD147 contributes to the formation of the 3D spheroid structure, and whether spheroids, which are often used to study proliferation and drug resistance, could better model the EMT process and the metastatic properties of cells, and improve our understanding of the role of EMMPRIN in them.

Methods

We used the parental mouse CT26 colon carcinoma (CT26-WT) cells, and infected them with a lentivirus vector to knock down EMMPRIN expression (CT26-KD cells), or with an empty lentivirus vector (CT26-NC) that served as a negative control. In some cases, we repeated the experiments with the 4T1 or LLC cell lines. We compared the magnitude of change between CT26-KD and CT26-WT/NC cells in different metastatic properties in cells seeded as monolayers or as spheroids formed by the scaffold-free liquid overlay method.

Results

We show that reduced EMMPRIN expression changed the morphology of cells and their spatial organization in both 2D and 3D models. The 3D models more clearly demonstrated how reduced EMMPRIN expression inhibited proliferation and the angiogenic potential, while it enhanced drug resistance, invasiveness, and EMT status, and moreover it enhanced cell dormancy and prevented CT26-KD cells from forming metastatic-like lesions when seeded on basement membrane extract (BME). Most interestingly, this approach enabled us to identify that EMMPRIN and miR-146a-5p form a negative feedback loop, thus identifying a key mechanism for EMMPRIN activities. These results underline EMMPRIN role as a gatekeeper that prevents dormancy, and suggest that EMMPRIN links EMT characteristics to the process of spheroid formation.

Conclusions

Thus, 3D models can help identify mechanisms by which EMMPRIN facilitates tumor and metastasis progression, which might render EMMPRIN as a promising target for anti-metastatic tumor therapy.

SLC3A2, as an indirect target gene of ALDH2, exacerbates alcohol-associated liver cancer via the sphingolipid biosynthesis pathway

Excessive drinking is one of the main causes of liver cancer. In the process of alcohol metabolism, aldehyde dehydrogenase 2 (ALDH2) is the key enzyme of acetaldehyde metabolism. ALDH2 gene deficiency is positively associated with the risk of hepatocellular carcinoma (HCC). However, no studies have shown a connection between ALDH2 and another metabolic regulatory gene, SLC3A2. In this study, we analyzed the expression levels of ALDH2 and SLC3A2 in liver cancer tissues based on the TCGA database. Subsequently, we constructed ALDH2 knockout and SLC3A2 knock-in transgenic mice to check the roles of ALDH2 and SLC3A2 in tumorigenesis in vivo. In addition, we examined the mechanisms of ALDH2 and SLC3A2 in HCC cells using small RNA interference technology. Consistent with previous studies, we also confirmed the functions of ALDH2 in inhibiting hepatocarcinogenesis, while SLC3A2 had the opposite effect. The main finding of this study is that ALDH2 inhibited BSG expression through the TGF-β1 pathway, which indirectly inhibited SLC3A2 expression; subsequently, the sphingolipid metabolism pathway was also inhibited in HCC cells. Therefore, SLC3A2 is a novel target for HCC treatment.

Knocking-Down CD147/EMMPRIN Expression in CT26 Colon Carcinoma Forces the Cells into Cellular and Angiogenic Dormancy That Can Be Reversed by Interactions with Macrophages

Metastasis in colorectal cancer is responsible for most of the cancer-related deaths. For metastasis to occur, tumor cells must first undergo the epithelial-to-mesenchymal transition (EMT), which is driven by the transcription factors (EMT-TFs) Snail, Slug twist1, or Zeb1, to promote their migration. In the distant organs, tumor cells may become dormant for years, until signals from their microenvironment trigger and promote their outgrowth. Here we asked whether CD147/EMMPRIN controls entry and exit from dormancy in the aggressive and proliferative (i.e., non-dormant) CT26 mouse colon carcinoma cells, in its wild-type form (CT26-WT cells). To this end, we knocked down EMMPRIN expression in CT26 cells (CT26-KD), and compared their EMT and cellular dormancy status (e.g., proliferation, pERK/pP38 ratio, vimentin expression, expression of EMT-TFs and dormancy markers), and angiogenic dormancy (e.g., VEGF and MMP-9 secretion, healing of the wounded bEND3 mouse endothelial cells), to the parental cells (CT26-WT). We show that knocking-down EMMPRIN expression reduced the pERK/pP38 ratio, enhanced the expression of vimentin, the EMT-TFs and the dormancy markers, and reduced the proliferation and angiogenic potential, cumulatively indicating that cells were pushed towards dormancy. When macrophages were co-cultured with both types of CT26 cells, the CT26-WT cells increased their angiogenic potential, but did not change their proliferation, state of EMT, or dormancy, whereas the CT26-KD cells exhibited values mostly similar to those of the co-cultured CT26-WT cells. Addition of recombinant TGFβ or EMMPRIN that simulated the presence of macrophages yielded similar results. Combinations of low concentrations of TGFβ and EMMPRIN had a minimal additive effect only in the CT26-KD cells, suggesting that they work along the same signaling pathway. We conclude that EMMPRIN is important as a gatekeeper that prevents cells from entering a dormant state, and that macrophages can promote an exit from dormancy.

CD147 and MMPs as key factors in physiological and pathological processes

Cluster of differentiation 147 (CD147) or extracellular matrix metalloproteinase inducer (EMMPRIN) is a transmembrane glycoprotein that induces the synthesis of matrix metalloproteinases (MMPs). MMPs, as zinc-dependent proteases and versatile enzymes, play critical roles in the degradation of the extracellular matrix (ECM) components, cleaving of the receptors of cellular surfaces, signaling molecules, and other precursor proteins, which may lead to attenuation or activation of such targets. CD147 and MMPs play essential roles in physiological and pathological conditions and any disorder in the expression, synthesis, or function of CD147 and MMPs may be associated with various types of disease. In this review, we have focused on the roles of CD147 and MMPs in some major physiological and pathological processes.

CD147 contributes to SARS-CoV-2-induced pulmonary fibrosis

COVID-19 patients can develop clinical and histopathological features associated with fibrosis, but the pathogenesis of fibrosis remains poorly understood. CD147 has been identified as a universal receptor for SARS-CoV-2 and its variants, which could initiate COVID-19-related cytokine storm. Here, we systemically analyzed lung pathogenesis in SARS-CoV-2- and its delta variant-infected humanized CD147 transgenic mice. Histopathology and Transmission Electron Microscopy revealed inflammation, fibroblast expansion and pronounced fibrotic remodeling in SARS-CoV-2-infected lungs. Consistently, RNA-sequencing identified a set of fibrosis signature genes. Furthermore, we identified CD147 as a crucial regulator for fibroblast activation induced by SARS-CoV-2. We found conditional knockout of CD147 in fibroblast suppressed activation of fibroblasts, decreasing susceptibility to bleomycin-induced pulmonary fibrosis. Meplazumab, a CD147 antibody, was able to inhibit the accumulation of activated fibroblasts and the production of ECM proteins, thus alleviating the progression of pulmonary fibrosis caused by SARS-CoV-2. In conclusion, we demonstrated that CD147 contributed to SARS-CoV-2-triggered progressive pulmonary fibrosis and identified CD147 as a potential therapeutic target for treating patients with post-COVID-19 pulmonary fibrosis.

Hepatogenesis and hepatocarcinogenesis: Alignment of the main signaling pathways

Development is a symphony of cells differentiation in which different signaling pathways are orchestrated at specific times and periods to form mature and functional cells from undifferentiated cells. The similarity of the gene expression profile in malignant and undifferentiated cells is an interesting topic that has been proposed for many years and gave rise to the differentiation-therapy concept, which appears a rational insight and should be reconsidered. Hepatocellular carcinoma (HCC), as the sixth common cancer and the third leading cause of cancer death worldwide, is one of the health-threatening complications in communities where hepatotropic viruses are endemic. Sedentary lifestyle and high intake of calories are other risk factors. HCC is a complex condition in which various dimensions must be addressed, including heterogeneity of cells in the tumor mass, high invasiveness, and underlying diseases that limit the treatment options. Under these restrictions, recognizing, and targeting common signaling pathways during liver development and HCC could expedite to a rational therapeutic approach, reprograming malignant cells to well-differentiated ones in a functional state. Accordingly, in this review, we highlighted the commonalities of signaling pathways in hepatogenesis and hepatocarcinogenesis, and comprised an update on the current status of targeting these pathways in laboratory studies and clinical trials.

Rs6757 in microRNA-3976 binding site of CD147 confers risk of hepatocellular carcinoma in South Chinese population

Background

Cluster of differentiation 147 (CD147) overexpression plays a key role in the proliferation, differentiation, invasion, metastasis, and prognosis of hepatocellular carcinoma (HCC). The aim of this study was to explore the relationship between rs6757 and the HCC risk in the South Chinese population, and the functional significance of rs6757 by affecting the efficacy of microRNA-3976 (miR-3976) binding to the CD147 3′-UTR.

Methods

We performed a retrospective case-control study to analyze the association between rs6757 and the risk of HCC. We chose candidate microRNAs with the potential of interacting with rs6757 through a series of silico analyses. A luciferase reporter gene assay was implemented to detect the binding extent of microRNAs to each polymorphic allele of rs6757.

Results

An obvious association between rs6757 and the risk of HCC was detected in C vs. T (OR = 1.826, 95% CI [1.263–2.642]), CC vs. TT (OR = 4.513, 95% CI [1.510–13.489]), dominant genetic model (OR = 1.824, 95% CI [1.120–2.965]), and recessive genetic model (OR = 3.765, 95% CI [1.286–11.020]). Bioinformatics analysis indicated that miR-3976 binding sites containing the rs6757-T allele had lower free energies than those with the C allele, the lower free energies, the higher affinities. Luciferase activity was remarkably decreased by miR-3976 binding to the CD147 3′-UTR bearing rs6757 T allele, which could be reversed by miR-3976 inhibitors. Furthermore, miR-3976 reduced the luciferase expression in a manner of dose-dependent when cotransfected with constructs with the CD147-TT-pSICHECK2.

Conclusions

The research we have done suggests that rs6757 confers the CD147 allele-specific translational suppression by miR-3976, which provides a theoretical basis for antineoplastic therapy targeting CD147.

The Multiple Roles of CD147 in the Development and Progression of Oral Squamous Cell Carcinoma: An Overview

Cluster of differentiation (CD)147, also termed extracellular matrix metalloprotease inducer or basigin, is a glycoprotein ubiquitously expressed throughout the human body, the oral cavity included. CD147 actively participates in physiological tissue development or growth and has important roles in reactive processes such as inflammation, immunity, and tissue repair. It is worth noting that deregulated expression and/or activity of CD147 is observed in chronic inflammatory or degenerative diseases, as well as in neoplasms. Among the latter, oral squamous cell carcinoma (OSCC) is characterized by an upregulation of CD147 in both the neoplastic and normal cells constituting the tumor mass. Most interestingly, the expression and/or activity of CD147 gradually increase as healthy oral mucosa becomes inflamed; hyperplastic/dysplastic lesions are then set on, and, eventually, OSCC develops. Based on these findings, here we summarize published studies which evaluate whether CD147 could be employed as a marker to monitor OSCC development and progression. Moreover, we describe CD147-promoted cellular and molecular events which are relevant to oral carcinogenesis, with the aim to provide useful information for assessing whether CD147 may be the target of novel therapeutic approaches directed against OSCC.

Identifying In Vitro Cultured Human Hepatocytes Markers with Machine Learning Methods Based on Single-Cell RNA-Seq Data

Cell transplantation is an effective method for compensating for the loss of liver function and improve patient survival. However, given that hepatocytes cultivated in vitro have diverse developmental processes and physiological features, obtaining hepatocytes that can properly function in vivo is difficult. In the present study, we present an advanced computational analysis on single-cell transcriptional profiling to resolve the heterogeneity of the hepatocyte differentiation process in vitro and to mine biomarkers at different periods of differentiation. We obtained a batch of compressed and effective classification features with the Boruta method and ranked them using the Max-Relevance and Min-Redundancy method. Some key genes were identified during the in vitro culture of hepatocytes, including CD147, which not only regulates terminally differentiated cells in the liver but also affects cell differentiation. PPIA, which encodes a CD147 ligand, also appeared in the identified gene list, and the combination of the two proteins mediated multiple biological pathways. Other genes, such as TMSB10, TMEM176B, and CD63, which are involved in the maturation and differentiation of hepatocytes and assist different hepatic cell types in performing their roles were also identified. Then, several classifiers were trained and evaluated to obtain optimal classifiers and optimal feature subsets, using three classification algorithms (random forest, k-nearest neighbor, and decision tree) and the incremental feature selection method. The best random forest classifier with a 0.940 Matthews correlation coefficient was constructed to distinguish different hepatic cell types. Finally, classification rules were created for quantitatively describing hepatic cell types. In summary, This study provided potential targets for cell transplantation associated liver disease treatment strategies by elucidating the process and mechanism of hepatocyte development at both qualitative and quantitative levels.

Mini-Review: Can the Metastatic Cascade Be Inhibited by Targeting CD147/EMMPRIN to Prevent Tumor Recurrence?

Solid tumors metastasize very early in their development, and once the metastatic cell is lodged in a remote organ, it can proliferate to generate a metastatic lesion or remain dormant for long periods. Dormant cells represent a real risk for future tumor recurrence, but because they are typically undetectable and insensitive to current modalities of treatment, it is difficult to treat them in time. We describe the metastatic cascade, which is the process that allows tumor cells to detach from the primary tumor, migrate in the tissue, intravasate and extravasate the lymphatics or a blood vessel, adhere to a remote tissue and eventually outgrow. We focus on the critical enabling role of the interactions between tumor cells and immune cells, especially macrophages, in driving the metastatic cascade, and on those stages that can potentially be targeted. In order to prevent the metastatic cascade and tumor recurrence, we would need to target a molecule that is involved in all of the steps of the process, and evidence is brought to suggest that CD147/EMMPRIN is such a protein and that targeting it blocks metastasis and prevents tumor recurrence.

Active demethylation upregulates CD147 expression promoting non-small cell lung cancer invasion and metastasis

Non-small cell lung cancer (NSCLC) is a fatal disease, and its metastatic process is poorly understood. Although aberrant methylation is involved in tumor progression, the mechanisms underlying dynamic DNA methylation remain to be elucidated. It is significant to study the molecular mechanism of NSCLC metastasis and identify new biomarkers for NSCLC early diagnosis. Here, we performed MeDIP-seq and hMeDIP-seq analyses to detect the genes regulated by dynamic DNA methylation. Comparison of the 5mC and 5hmC sites revealed that the CD147 gene underwent active demethylation in NSCLC tissues compared with normal tissues, and this demethylation upregulated CD147 expression. Significantly high levels of CD147 expression and low levels of promoter methylation were observed in NSCLC tissues. Then, we identified the CD147 promoter as a target of KLF6, MeCP2, and DNMT3A. Treatment of cells with TGF-β triggered active demethylation involving loss of KLF6/MeCP2/DNMT3A and recruitment of Sp1, Tet1, TDG, and SMAD2/3 transcription complexes. A dCas9-SunTag-DNMAT3A-sgCD147-targeted methylation system was constructed to reverse CD147 expression. The targeted methylation system downregulated CD147 expression and inhibited NSCLC proliferation and metastasis in vitro and in vivo. Accordingly, we used cfDNA to detect the levels of CD147 methylation in NSCLC tissues and found that the CD147 methylation levels exhibited an inverse relationship with tumor size, lymphatic metastasis, and TNM stage. In conclusion, this study clarified the mechanism of active demethylation of CD147 and suggested that the targeted methylation of CD147 could inhibit NSCLC invasion and metastasis, providing a highly promising therapeutic target for NSCLC.

Hepatocellular Carcinoma Differentiation: Research Progress in Mechanism and Treatment

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Although progress has been made in diagnosis and treatment, morbidity and mortality continue to rise. Chronic liver disease and liver cirrhosis are still the most important risk factors for liver cancer. Although there are many treatments, it can only be cured by orthotopic liver transplantation (OLT) or surgical resection. And the worse the degree of differentiation, the worse the prognosis of patients with liver cancer. Then it can be considered that restoring a better state of differentiation may improve the prognosis. The differentiation treatment of liver cancer is to reverse the dedifferentiation process of hepatocytes to liver cancer cells by means of drugs, improve the differentiation state of the tumor, and restore the normal liver characteristics, so as to improve the prognosis. Understanding the mechanism of dedifferentiation of liver cancer can provide ideas for drug design. Liver enrichment of transcription factors, imbalance of signal pathway and changes of tumor microenvironment can promote the occurrence and development of liver cancer, and restoring its normal level can inhibit the malignant behavior of tumor. At present, some drugs have been proved to be effective, but more clinical data are needed to support the effectiveness and reliability of drugs. The differentiation treatment of liver cancer is expected to become an important part of the treatment of liver cancer in the future.

Novel Cellular Therapies for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer related death worldwide. Most patients present with advanced disease, and current gold-standard management using tyrosine kinase inhibitors or immune checkpoint inhibitors (ICIs) offers modest clinical benefit. Cellular immune therapies targeting HCC are currently being tested in the laboratory and in clinical trials. Here, we review the landscape of cellular immunotherapy for HCC, defining antigenic targets, outlining the range of cell therapy products being applied in HCC (such as CAR-T and TCR-T), and exploring how advanced engineering solutions may further enhance this therapeutic approach.

Cellular heterogeneity and plasticity in liver cancer

Hepatocarcinogenesis involves complex genetic and cellular dysregulations which drive the formation of hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, with extensive heterogeneity. In contrast to the broad spectrum of molecularly driven therapies available for defined patient groups in certain cancer types, unfortunately the treatment options for HCC are highly limited. The lack of representative molecular and cellular signatures in the heterogeneous HCC tumors that can effectively guide the choice of the most appropriate treatment among the patients unavoidably limits the treatment outcome. Advancement and wide availability of the next-generation sequencing technologies have empowered us to examine and capture not only the detailed genetic alterations of the HCC cells but also the precise composition of different cell types within the tumor microenvironment and their interactions with the HCC cells at an unprecedented level. The information generated has provided new insight and better defined the inter-patient intertumoral heterogeneity, intra-patient intratumoral heterogeneity as well as the plasticity of HCC cells. These collectively provide a robust scientific basis in guiding the development and use of targeted therapy and immunotherapy. To complement, liquid biopsy coupled with high-sensitivity sequencing could potentially be adopted as a more practical and safer approach to detect and reflect the tumor heterogeneity in HCC patients in guiding the choice of treatment and monitoring disease progression.

The dichotomous role of TGF-β in controlling liver cancer cell survival and proliferation

Hepatocellular carcinoma (HCC) is the major form of primary liver cancer and one of the most prevalent and life-threatening malignancies globally. One of the hallmarks in HCC is the sustained cell survival and proliferative signals, which are determined by the balance between oncogenes and tumor suppressors. Transforming growth factor beta (TGF-β) is an effective growth inhibitor of epithelial cells including hepatocytes, through induction of cell cycle arrest, apoptosis, cellular senescence, or autophagy. The antitumorigenic effects of TGF-β are bypassed during liver tumorigenesis via multiple mechanisms. Furthermore, along with malignant progression, TGF-β switches to promote cancer cell survival and proliferation. This dichotomous nature of TGF-β is one of the barriers to therapeutic targeting in liver cancer. Thereafter, understanding the underlying molecular mechanisms is a prerequisite for discovering novel antitumor drugs that may specifically disable the growth-promoting branch of TGF-β signaling or restore its tumor-suppressive arm. This review summarizes how TGF-β inhibits or promotes liver cancer cell survival and proliferation, highlighting the functional switch mechanisms during the process.

Deficiency of CD147 Attenuated Non-alcoholic Steatohepatitis Progression in an NLRP3-Dependent Manner

Cluster of differentiation 147 (CD147) is a transmembrane glycoprotein belonging to the immunoglobulin superfamily. CD147 overexpression has been reported to facilitate the development of hepatocellular carcinoma (HCC) and influence immunologic disorders. Although increased expression of CD147 was reported in non-alcoholic steatohepatitis (NASH), functions of CD147 in NASH have not been evaluated. Firstly, we confirmed that CD147 expression was increased in the liver tissues from methionine-choline-deficient (MCD) diet-induced NASH model mice and NASH patients. Mice with hepatocyte-specific CD147 deletion exhibited attenuated NASH phenotypes, including reduced steatosis, liver injury, hepatocyte apoptosis and inflammatory cytokines IL-1β/IL-18 secretion. Following the administration of the MCD diet, NLRP3 expression was increased gradually along with CD147 expression. Furthermore, CD147 deletion inhibited the NF-κB/NLRP3 signaling pathway in both MCD diet-induced mice and primary hepatocytes. Finally, CypA inhibitor TMN355 attenuated liver steatosis and injury and inhibited NF-κB/NLRP3 signaling pathway. Therefore, our results suggest that CD147 played a vital role in NASH pathogenesis by regulating the inflammatory response, and CypA/CD147 could be attractive therapeutic targets for NASH treatment.

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.

Hepatic CD147 knockout modulates liver steatosis and up-regulates autophagy in high-fat-diet-induced NAFLD mice

Nonalcoholic fatty liver disease (NAFLD) represents a global health problem. Impaired autophagy has been implicated in the pathogenesis of NAFLD, and CD147 is recognized to regulate lipid metabolism in a variety of cell types. This study was initiated with the aim to identify molecular makers expressed in hepatocytes that are significantly altered during the pathogenesis of NAFLD and closely associated with hepatic steatosis and autophagy. In this study, CD147 was found to be significantly associated with steatosis and autophagy in both clinical patients with NAFLD and NAFLD mouse models. In high-fat-diet-induced NAFLD mice, hepatic-specific CD147 knockout markedly reduced body weight, liver weight, serum aspartate aminotransaminase (AST) and alanine aminotransaminase (ALT), and liver steatosis. In addition, hepatic CD147 gene knockout noticeably promoted autophagy in NAFLD mice (LC3 expression was increased with decreased P62 expression; molecular markers of autophagy). Moreover, we found that CD147 expression was significantly associated with AKT/mTOR signaling pathway; thus, suggesting that CD147 is involved in the regulation of autophagy and steatosis in NAFLD. In conclusion, this study has provided in vivo evidence for the putative role of CD147 in the pathogenesis of NAFLD and a valuable experimental basis for considering CD147 as a therapeutic target to prevent hepatic steatosis in patients with NAFLD.

Doxycycline Inducible Chimeric Antigen Receptor T Cells Targeting CD147 for Hepatocellular Carcinoma Therapy

Chimeric antigen receptor T cell (CAR-T) therapy to hematological malignancies has demonstrated tremendous clinical outcomes. However, the therapeutic efficacy of CAR-T cells in solid tumors remains limited due to the scarcity of tumor-specific antigen targets and the poor infiltration of CAR-T cells into tumor tissue. In this study, we developed a novel inducible CAR-T cell system which targets CD147, a tumor-associated antigen for hepatocellular carcinoma (HCC). To minimize potential toxicities of CAR-T cell therapy, the Tet-On 3G system was introduced to induce CD147CAR expression in the right place at the right time. Specifically, Tet-CD147CAR lentiviral vector (LV-Tet-CD147CAR) was constructed, which comprised CD147CAR controlled by the Tet-On system. Tet-CD147CART cells were successfully generated from activated T cells by infection with LV-Tet-CD147CAR. Proliferation, cytotoxicity, and cytokine secretion of Tet-CD147CART cells were significantly increased against CD147-positive cancer cells in the presence of doxycycline (Dox) compared to Tet-CD147CART cells in the absence of Dox and PBMCs. Consistently, in vivo studies indicated that the tumor growth in nude mice was significantly inhibited by (Dox+) Tet-CD147CART cells through multiple intratumoral administration. Taken together, our results indicated that the expression and activity of CD147CAR were controlled by Dox both in vitro and in vivo, which facilitated decreased toxicity and adverse effects to CAR-T cell therapy. Moreover, this study provides viable evidence in support of the potential benefits and translation of this strategy of CAR-T cells targeting CD147 for the treatment of patients with HCC.

Contextual Regulation of TGF-β Signaling in Liver Cancer

Primary liver cancer is one of the leading causes for cancer-related death worldwide. Transforming growth factor beta (TGF-β) is a pleiotropic cytokine that signals through membrane receptors and intracellular Smad proteins, which enter the nucleus upon receptor activation and act as transcription factors. TGF-β inhibits liver tumorigenesis in the early stage by inducing cytostasis and apoptosis, but promotes malignant progression in more advanced stages by enhancing cancer cell survival, EMT, migration, invasion and finally metastasis. Understanding the molecular mechanisms underpinning the multi-faceted roles of TGF-β in liver cancer has become a persistent pursuit during the last two decades. Contextual regulation fine-tunes the robustness, duration and plasticity of TGF-β signaling, yielding versatile albeit specific responses. This involves multiple feedback and feed-forward regulatory loops and also the interplay between Smad signaling and non-Smad pathways. This review summarizes the known regulatory mechanisms of TGF-β signaling in liver cancer, and how they channel, skew and even switch the actions of TGF-β during cancer progression.

Basolateral CD147 induces hepatocyte polarity loss by E-cadherin ubiquitination and degradation in hepatocellular carcinoma progress

Hepatocytes are epithelial cells with highly specialized polarity. The disorder and loss of hepatocyte polarity leads to a weakness of cell adhesion and connection, the induction of epithelial-mesenchymal transition, and eventually the occurrence of hepatocellular carcinoma (HCC). Cluster of differentiation 147 (CD147), a tumor-related glycoprotein, promotes epithelial-mesenchymal transition and the invasion of HCC. However, the function of CD147 in hepatocyte depolarization is unknown. Here we identified that CD147 was basolaterally polarized in hepatocyte membrane of liver tissues and HepG2 cells. CD147 not only promoted transforming growth factor-β1-mediated hepatocyte polarity loss but also directly induced endocytosis and down-regulation of E-cadherin which contributed to hepatocyte depolarization. Overexpression of CD147 induced Src activation and subsequently recruited ubiquitin ligase Hakai for E-cadherin ubiquitination and lysosomal degradation, leading to decreases of partitioning defective 3 expression and β-catenin nuclear translocation. This signal transduction was initiated by competitive binding of CD147 with integrin β1 that interrupted the interaction between the Arg-Gly-Asp motif of fibronectin and integrin β1. The specific antibodies targeting integrin α5 and β1 reversed the decrease of E-cadherin and partitioning defective 3 levels induced by CD147 overexpression. In human liver tissues, CD147 polarity rates significantly declined from liver cirrhosis (71.4%) to HCC (10.4%). CD147-polarized localization negatively correlated with Child-Pugh scores in human liver cirrhosis (r = -0.6092, P < 0.0001) and positively correlated with differentiation grades in HCC (r = 0.2060, P = 0.004). HCC patients with CD147-polarized localization had significantly better overall survival than patients with CD147 nonpolarity (P = 0.021).

CONCLUSION

The ectopic CD147-polarized distribution on basolateral membrane promotes hepatocyte depolarization by activation of the CD147-integrin α5β1-E-cadherin ubiquitination-partitioning defective 3 decrease and β-catenin translocation signaling cascade, replenishing a molecular pathway in hepatic carcinogenesis. (Hepatology 2018;68:317-332).

p-Hydroxylcinnamaldehyde slows the progression of 4NQO-induced oesophageal tumourigenesis via the RhoA-MAPK signaling pathway

p-Hydroxylcinnamaldehyde isolated from the Cochinchina momordica seed (CMSP) has been identified to inhibit growth and metastasis in oesophageal squamous cell carcinoma (ESCC) by inducing differentiation. The aim of the present study was to evaluate the effect and underlying mechanism of CMSP on 4-nitroquinoline 1-oxide (4NQO)-induced oesophageal tumourigenesis. In the present study, a mouse model of oesophageal preneoplastic lesions was established by providing 4NQO-containing drinking water to C57BL/6 mice. The effect of CMSP on tumourigenesis induced by the chemical mutagen and the effect of CMSP on immune function were investigated. The results showed that the incidence and pathological stage of atypical hyperplasia in oesophageal tissues were significantly reduced in CMSP-treated mice compared with untreated mice. Immunohistochemistry and pull-down assay results revealed that the expression levels of p-ERK1/2, p-SAPK/JNK, and GTP-RhoA were significantly decreased in the oesophageal tissue of CMSP-treated mice. In addition, the proportions of CD4⁺ T cells, CD8⁺ T cells, and NK cells were increased, while the proportion of CD4⁺ CD25⁺ regulatory T cells (Tregs) was decreased, in the peripheral blood of CMSP-treated mice. These results indicated that CMSP could hamper 4NQO-induced oesophageal tumourigenesis by regulating the RhoA-ERK/JNK signaling pathway and promoting immune system function, thus providing a new potential strategy for treating preneoplastic lesions of the oesophagus.

Experimental study on TGF-β1-mediated CD147 expression in oral submucous fibrosis

OBJECTIVE

Although previous evidence indicates that CD147 is closely involved in the progression of organ fibrosis and various signaling pathways have been proven to regulate its expression, the role of CD147 in oral submucous fibrosis (OSF) remains largely unknown.

METHODS

In this study, we investigated the expression of CD147 and transforming growth factor β1 (TGF-β1) in human samples of an OSF tissue array by immunohistopathology. Pearson's correlation analysis was conducted to explore the correlation between CD147 and TGF-β1. Immunofluorescence and Western blotting were used to investigate to levels of CD147 in Human Oral Keratinocytes (HOKs) followed by TGF-β1 or LY2157299, an inhibitor of TGF-β1 receptor and arecoline stimulation.

RESULTS

We found that CD147 was highly expressed in both HOKs and the fibrotic oral mucosa and that this expression was correlated with TGF-β1 expression. Additionally, CD147 levels were significantly associated with the fibrosis stage. The TGF-β1 signaling pathway was found to be mainly responsible for CD147 up-regulation after arecoline treatment whereas inhibition of TGF-β1 down-regulated CD147 expression.

CONCLUSION

Our findings suggest arecoline promotes CD147 expression via the TGF-β1 signaling pathway in HOKs, whereas overexpression of CD147 may promote OSF progression.

N-glycosylation by N-acetylglucosaminyltransferase V enhances the interaction of CD147/basigin with integrin β1 and promotes HCC metastasis

While the importance of protein N-glycosylation in cancer cell migration is well appreciated, the precise mechanisms by which N-acetylglucosaminyltransferase V (GnT-V) regulates cancer processes remain largely unknown. In the current study, we report that GnT-V-mediated N-glycosylation of CD147/basigin, a tumor-associated glycoprotein that carries β1,6-N-acetylglucosamine (β1,6-GlcNAc) glycans, is upregulated during TGF-β1-induced epithelial-to-mesenchymal transition (EMT), which correlates with tumor metastasis in patients with hepatocellular carcinoma (HCC). Interruption of β1,6-GlcNAc glycan modification of CD147/basigin decreased matrix metalloproteinase (MMP) expression in HCC cell lines and affected the interaction of CD147/basigin with integrin β1. These results reveal that β1,6-branched glycans modulate the biological function of CD147/basigin in HCC metastasis. Moreover, we showed that the PI3K/Akt pathway regulates GnT-V expression and that inhibition of GnT-V-mediated N-glycosylation suppressed PI3K signaling. In summary, β1,6-branched N-glycosylation affects the biological function of CD147/basigin and these findings provide a novel approach for the development of therapeutic strategies targeting metastasis. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Differentiation-inducing therapeutic effect of Notch inhibition in reversing malignant transformation of liver normal stem cells via MET

Background

Liver cancer stem cells (LCSCs) are the key factors for cancer metastasis, recurrent, and drug resistance. LCSCs are originated from either hepatocytes dedifferentiation or differentiation arresting of liver normal stem cells (LNSCs). Differentiation-inducing therapy is a novel strategy in solid tumors. Furthermore, Notch signaling pathway has been proved to play important role in the process of hepatocytes differentiation. In previous study, a malignant transformation cellular model of LNSCs has been built up, and in this study we are trying to illustrate whether inhibition of Notch can reverse this malignant tendency and drive these malignant cells back to differentiate into mature hepatocytes.

Results

Inhibition of Notch signaling pathway can down-regulate the stemness-related cancer markers, lower the proliferative status, alleviate the invasive characteristic, or attenuate the metastasis tendency. What is more, it can help the malignantly transformed cells to regain the mature hepatic function of glucagon synthesis, urea metabolism, albumin production, and indocyanine-green (ICG) clearance.

Materials and Methods

HOX transcript antisense RNA (HOTAIR) expression was enhanced in LNSCs via lentivirus transduction to set up the malignant transformation cellular model. Then, a Notch inhibitor was applied to induce malignantly transformed cells differentiate into mature hepatocytes, and malignant abilities of proliferation, invasiveness, tumorigenesis as well as mature hepatocyte function were observed and compared.

Conclusions

The data demonstrate that the anti-tumor effects of Notch inhibition may lie not only on killing the cancer cells or LCSCs directly, it can also induce the LCSCs differentiation into mature hepatocytes via mesenchymal-epithelial transition (MET) progress or downgrade the malignancy.

CD147 expression was positively linked to aggressiveness and worse prognosis of gastric cancer: a meta and bioinformatics analysis

CD147 (also named as Basigin or EMMPRIN) might promote cancer invasion and metastasis by inducing MMP and VEGF synthesis in tumor microenvironment. We performed a systematic meta and bioinformatics analysis through multiple online databases up to March 14, 2017. Up-regulated CD147 expression was found in gastric cancer, compared with normal mucosa (p < 0.05). The male patients with gastric cancer showed higher CD147 expression than the female ones (p < 0.0001). CD147 expression was positively correlated with tumor size, depth of invasion, lymph node metastasis, TNM staging and unfavorable prognosis of gastric cancer (p < 0.05). At mRNA level, CD147 expression was higher in intestinal-type and mixed-type gastric carcinomas than normal tissues (p < 0.05). CD147 mRNA expression was negatively associated with histological grading and dedifferentiation of gastric cancer (p < 0.05). A higher CD147 mRNA expression was negatively correlated with overall and progression-free survival rates of all cancer patients, even stratified by clinicopathological features (p < 0.05). These findings indicated that CD147 expression might be employed as a potential marker to indicate gastric carcinogenesis and subsequent progression, even prognosis.