Human tumor cells induce angiogenesis through positive feedback between CD147 and insulin-like growth factor-I

Glucose Promotes EMMPRIN/CD147 and the Secretion of Pro-Angiogenic Factors in a Co-Culture System of Endothelial Cells and Monocytes

Vascular complications in Type 2 diabetes mellitus (T2DM) patients increase morbidity and mortality. In T2DM, angiogenesis is impaired and can be enhanced or reduced in different tissues ("angiogenic paradox"). The present study aimed to delineate differences between macrovascular and microvascular endothelial cells that might explain this paradox. In a monoculture system of human macrovascular (EaHy926) or microvascular (HMEC-1) endothelial cell lines and a monocytic cell line (U937), high glucose concentrations (25 mmole/L) increased the secretion of the pro-angiogenic factors CD147/EMMPRIN, VEGF, and MMP-9 from both endothelial cells, but not from monocytes. Co-cultures of EaHy926/HMEC-1 with U937 enhanced EMMPRIN and MMP-9 secretion, even in low glucose concentrations (5.5 mmole/L), while in high glucose HMEC-1 co-cultures enhanced all three factors. EMMPRIN mediated these effects, as the addition of anti-EMMPRIN antibody decreased VEGF and MMP-9 secretion, and inhibited the angiogenic potential assessed through the wound assay. Thus, the minor differences between the macrovascular and microvascular endothelial cells cannot explain the angiogenic paradox. Metformin, a widely used drug for the treatment of T2DM, inhibited EMMPRIN, VEGF, and MMP-9 secretion in high glucose concentration, and the AMPK inhibitor dorsomorphin enhanced it. Thus, AMPK regulates EMMPRIN, a key factor in diabetic angiogenesis, suggesting that targeting EMMPRIN may help in the treatment of diabetic vascular complications.

The role of Colchicine on actin polymerization dynamics: as a potent anti-angiogenic factor

Over the years, cancer research has focused on different strategies to discover drugs and therapies to treat the metastatic stage of cancer. This stage depends upon the type, and the cause of cancer. One of the central facts about any cancer invasion is the formation of new blood vessels that provide nutrients to these uncontrollably dividing cells. This phenomenon is called angiogenesis and is responsible for tumor progression and metastasis. Tumor angiogenesis is a sequential process wherein various angiogenic factors produced by tumor cells bind to receptors of endothelial cells. This stimulates the cytoskeletal protein, especially actin to reorganize themselves and undergo the process of canalization. The driving force for such membrane transformation is spatially and temporally-regulated by polymerization of submembrane actin filaments. So far, Colchicine has been studied for its effectiveness in controlling microtubule reorganization during cell division, but its role is far from understood on actin polymerization. In our current study, we report the effect of Colchicine on actin polymerization dynamics using biophysical analysis like Right light scattering (RLS), Dynamic light scattering (DLS), Circular dichroism (CD) analysis, Scanning electron microscopy (SEM) study. Isothermal titration calorimetry (ITC) and kinetic measurements. Isothermal titration calorimetry (ITC) indicates multiple site binding for colchicine with actin aggregates. We have checked the in vivo effect of colchicine using end3 cells of Saccharomyces cerevisiae. We also report the anti-angiogenesis activity of colchicine via ex-ovo chicken chorioallantoic membrane (CAM) assay. We predict the target site of binding for the drug by docking studies. Based on our findings, we suggest the 'drug-repurposed' function for colchicine as a potential anti-angiogenic candidate.Communicated by Ramaswamy H. Sarma.

SARS-CoV-2 Entry: At the Crossroads of CD147 and ACE2

In late 2019, the betacoronavirus SARS-CoV-2 was identified as the viral agent responsible for the coronavirus disease 2019 (COVID-19) pandemic. Coronaviruses Spike proteins are responsible for their ability to interact with host membrane receptors and different proteins have been identified as SARS-CoV-2 interactors, among which Angiotensin-converting enzyme 2 (ACE2), and Basigin2/EMMPRIN/CD147 (CD147). CD147 plays an important role in human immunodeficiency virus type 1, hepatitis C virus, hepatitis B virus, Kaposi’s sarcoma-associated herpesvirus, and severe acute respiratory syndrome coronavirus infections. In particular, SARS-CoV recognizes the CD147 receptor expressed on the surface of host cells by its nucleocapsid protein binding to cyclophilin A (CyPA), a ligand for CD147. However, the involvement of CD147 in SARS-CoV-2 infection is still debated. Interference with both the function (blocking antibody) and the expression (knock down) of CD147 showed that this receptor partakes in SARS-CoV-2 infection and provided additional clues on the underlying mechanism: CD147 binding to CyPA does not play a role; CD147 regulates ACE2 levels and both receptors are affected by virus infection. Altogether, these findings suggest that CD147 is involved in SARS-CoV-2 tropism and represents a possible therapeutic target to challenge COVID-19.

Knockdown of EMMPRIN (OX47) in MRMT-1 Carcinoma Cells Inhibits Tumor Growth and Decreases Cancer-Induced Bone Destruction and Pain

Purpose

Bone destruction and pain caused by cancer is one of the most devastating complications of cancer patients with bone metastases, and it seriously affects the quality of patients’ life. Extracellular matrix metalloproteinase inducer (EMMPRIN) is a cell adhesion molecule with increased expression in a variety of tumors. This study focused to clarify the specific function of EMMPRIN in bone metastasis of breast cancer.

Materials and Methods

Adenovirus with shRNA-EMMPRIN was transfected into MRMT-1 rat breast carcinoma cells, and the MRMT-1 cells with different expression levels of EMMPRIN were implanted into the bone marrow cavity of rat tibia. Next, the effect of down-regulation of EMMPRIN was evaluated as follows: bone damage was detected by X-ray radiological and tartrate-resistant acid phosphatase staining; the tumor burden was evaluated by hematoxylin and eosin staining; the test of pain-related behaviors was assessed used the bilateral paw withdrawal mechanical threshold; and the levels of secretory factors in tumor conditioned medium were determined by using enzyme-linked immunosorbent assay.

Results

We found that down-regulation of EMMPRIN in tumor cells can simultaneously reduce tumor burden, relieve cancer-induced bone destruction and pain.

Conclusion

EMMPRIN is expected to be a therapeutic target for relieving bone metastasis of breast cancer and alleviating cancer-induced bone destruction and pain. The method of targeting EMMPRIN may be a promising strategy for the treatment of cancer in the future.

Primmorph extracts and mesohyls of marine sponges inhibit proliferation and migration of hepatocellular carcinoma cells in vitro

Cancer recurrence and severe side effects of currently being used chemotherapeutic agents reduce their clinical efficacy. Thus, there is a constant need to develop alternative anticancer drugs. Sustainable supply is an important challenge facing marine-based drug discovery. Primmorph, a 3D cell culture system, could provide a sustainable source to produce metabolites for anticancer drugs from marine sponges. In the present work, the anticancer activity of primmorph extracts and mesohyls of Negombata magnifica, Hemimycle arabica, Crella spinulata, and Stylissa carteri sponges was evaluated. Antiproliferative activity was studied in terms of cytotoxicity, colony formation, cell cycle, and apoptosis. Migration was assessed by migration assay and matrix metalloproteinase activity. The expression of proliferation and migration-related genes was analyzed using real time PCR. Migration and proliferation activities of HepG2 cells were inhibited by treatment with primmorph extracts and mesohyls of N. magnifica, H. arabica, and C. spinulata. The mesohyl of S. carteri did not show any anticancer activity although the primmorph extract led to cell cycle arrest. Among the selected sponge species, the primmorph extract of C. spinulata was the most promising anticancer agent regarding antiproliferative and antimigratory activities. In addition, primmorph extracts have the advantage of working under well-defined and controlled conditions, which allows the easy application as a bioreactor.

Non-target Genes Regulate miRNAs-Mediated Migration Steering of Colorectal Carcinoma

MicroRNAs (miRNAs) trigger a two-layer regulatory network directly or through transcription factors and their co-regulators. Unlike miR-375, the role of miR-145 and miR-224 in inhibiting or driving cancer cell migration is controversial. This study is a step towards addressing the potential of miR-375, miR-145 and miR-224 expression modulation to inhibit colorectal carcinoma (CRC) cells migration in vitro through regulation of non-target genes VEGFA, TGFβ1, IGF1, CD105 and CD44. Transwell migration assay results revealed a significant subdue of migration ability of cells transfected with miR-375 and miR-145 mimics and miR-224 inhibitor. Real time PCR data showed that expression of VEGFA, TGFβ1, IGF1, CD105 and CD44 was downregulated as a consequence of exogenous re-expression of miR-375 and inhibition of miR-224. On the other hand, ectopic expression of miR-145 did not affect VEGFA, TGFβ1 and CD44 expression, while it elevated CD105 and suppressed IGF1 expression. MAP4K4, a predicted target of miR-145, was validated as a target that could play a role in miR-145-mediated regulation of migration. At mRNA level, no change was observed in expression of MAP4K4 in cells with restored expression of miR-145, while western blotting analysis revealed a 25% reduction of protein level. By applying luciferase reporter assay, a significant decrease in luciferase activity was observed, supporting that miR-145 directly target 3' UTR of MAP4K4. The study highlighted the involvement of non-target genes VEGFA, TGFβ1, IGF1, CD105 and CD44 in mediating anti- and pro-migratory effect of miR-375 and miR-224, respectively, and validated MAP4K4 as a direct target of anti-migratory miR-145.

Repressing CD147 is a novel therapeutic strategy for malignant melanoma

CD147/basigin, a transmembrane protein, is a member of the immunoglobulin super family. Accumulating evidence has revealed the role of CD147 in the development and progression of various cancers, including malignant melanoma (MM). MM is a malignancy of pigment-producing cells that causes the greatest number of skin cancer-related deaths worldwide. CD147 is overexpressed in MM and plays an important role in cell viability, apoptosis, proliferation, invasion, and metastasis, probably by mediating vascular endothelial growth factor (VEGF) production, glycolysis, and multi-drug resistance (MDR). As a matrix metalloproteinase (MMP) inducer, CD147 could also promote surrounding fibroblasts to secrete abundant MMPs to further stimulate tumor cell invasion. Targeting CD147 has been shown to suppress MM in vitro and in vivo, highlighting the therapeutic potential of CD147 silencing in MM treatment. In this review article, we discuss CD147 and its biological roles, regulatory mechanisms, and potential application as a molecular target for MM.

TRAF6 regulates EGF-induced cell transformation and cSCC malignant phenotype through CD147/EGFR

TRAF6, a well-known adapter molecule, plays pivotal role in TLR/IL-1R associated signaling pathway. Although TRAF6 has been shown to have oncogenic activity in various malignant tumors, the details remain unclear. In this study, we demonstrated that TRAF6 facilitates Ras (G12V) and EGF-induced cellular transformation through EGFR. Silencing of TRAF6 expression significantly downregulated AP-1 activity, as well as MMP-2,9 expression after EGF stimulation. Furthermore, we found that TRAF6 plays an essential role in cutaneous squamous cell carcinoma (cSCC) malignant phenotypes, affecting cell growth and migration. CD147/Basigin, a transmembrane glycoprotein belonging to the immunoglobulin superfamily, is over-expressed in tumors and induces tumorigenesis. Our results showed that CD147 formed complex with EGFR and TRAF6. Knockdown of TRAF6 disrupted the CD147-EGFR complex, thereby inducing EGFR endocytosis. Therefore, TRAF6 might be a novel molecular target for cSCC prevention or therapy.

Up-regulated basigin-2 in microglia induced by hypoxia promotes retinal angiogenesis

Retinal microglia cells contribute to vascular angiogenesis and vasculopathy induced by relative hypoxia. However, its concrete molecular mechanisms in shaping retinal angiogenesis have not been elucidated. Basigin, being involved in tumour neovasculogenesis, is explored to exert positive effects on retinal angiogenesis induced by microglia. Therefore, we set out to investigate the expression of basigin using a well-characterized mouse model of oxygen-induced retinopathy, which recapitulated hypoxia-induced aberrant neovessel growth. Our results elucidate that basigin is overexpressed in microglia, which accumulating in retinal angiogenic sprouts. In vitro, conditioned media from microglia BV2 under hypoxia treatment increase migration and tube formation of retinal capillary endothelia cells, compared with media from normoxic condition. The angiogenic capacity of BV2 is inhibited after basigin knockdown by small interfering RNAs. A new molecular mechanism for high angiogenic capacity, whereby microglia cells release basigin via up-regulation of PI3K-AKT and IGF-1 pathway to induce angiogenesis is unveiled. Collectively, our results demonstrate that basigin from hypoxic microglia plays a pivotal pro-angiogenic role, providing new insights into microglia-promoting retinal angiogenesis.

Complex Determinants of Epithelial: Mesenchymal Phenotypic Plasticity in Ovarian Cancer

Unlike most epithelial malignancies which metastasize hematogenously, metastasis of epithelial ovarian cancer (EOC) occurs primarily via transcoelomic dissemination, characterized by exfoliation of cells from the primary tumor, avoidance of detachment-induced cell death (anoikis), movement throughout the peritoneal cavity as individual cells and multi-cellular aggregates (MCAs), adhesion to and disruption of the mesothelial lining of the peritoneum, and submesothelial matrix anchoring and proliferation to generate widely disseminated metastases. This exceptional microenvironment is highly permissive for phenotypic plasticity, enabling mesenchymal-to-epithelial (MET) and epithelial-to-mesenchymal (EMT) transitions. In this review, we summarize current knowledge on EOC heterogeneity in an EMT context, outline major regulators of EMT in ovarian cancer, address controversies in EMT and EOC chemoresistance, and highlight computational modeling approaches toward understanding EMT/MET in EOC.

Morphological analysis of human umbilical vein endothelial cells co-cultured with ovarian cancer cells in 3D: An oncogenic angiogenesis assay

Antiangiogenic therapy for cancer is a strategy targeted at tumour vasculature, often in combination with conventional cytotoxicity treatments. Animal testing is still the most common method used for evaluating the efficacy of new drugs but tissue-engineered in vitro models are becoming more acceptable for replacing and reducing the use of animals in anti-cancer drug screening. In this study, a 3D co-culture model of human endothelial cells and ovarian cancer cells was developed. This model has the potential to mimic the interactions between endothelial cells and ovarian cancer cells. The feasibility of applying this model in drug testing was explored here. The complex morphology of the co-culture system, which features development of both endothelial tubule-like structures and tumour structures, was analysed quantitatively by an image analysis method. The co-culture morphology integrity was maintained for 10 days and the potential of the model for anti-cancer drug testing was evaluated using Paclitaxel and Cisplatin, two common anti-tumour drugs with different mechanisms of action. Both traditional cell viability assays and quantitative morphological analyses were applied in the drug testing. Cisplatin proved a good example showing the advantages of morphological analysis of the co-culture model when compared with mono-culture of endothelial cells, which did not reveal an inhibitory effect of Cisplatin on the tubule-like endothelial structures. Thus, the tubule areas of the co-culture reflected the anti-angiogenesis potential of Cisplatin. In summary, in vitro cancer models can be developed using a tissue engineering approach to more closely mimic the characteristics of tumours in vivo. Combined with the image analysis technique, this developed 3D co-culture angiogenesis model will provide more reproducible and reliably quantified results and reveal further information of the drug's effects on both tumour cell growth and tumour angiogenesis.

Vector-mediated Tum-5 expression in neovascular endothelial cells for treating hepatocellular carcinoma

Hypervascular hepatocellular carcinoma (HCC) is one of the leading causes of cancer-associated mortality. Angiogenesis is an important contributor to HCC progression and metastasis; therefore, inhibiting angiogenesis may be an effective method of treating HCC. Tumstatin is a novel type of efficient endogenous vascular endothelial cell growth inhibiting factor. The anti-angiogenic activity of tumstatin is localized to the 54-132 amino acid region (Tum-5). In a previous study performed by our group, the gene fragment encoding Tum-5 was cloned and inserted into a pLXSN retroviral vector. In the present study, the anti-angiogenic effects of Tum-5 and the antitumor effects exerted by the pLXSN-Tum-5 vector in vivo were investigated. The results demonstrated that pLXSN-Tum-5 significantly inhibited the growth of human umbilical vein endothelial cells compared with pLXSN, but had no obvious effect on HepG2 cell growth. Moreover, the antitumor and anti-angiogenic activity of Tum-5 was examined in vivo using a xenograft of H22 HCC cells. The results indicated that pLXSN-Tum-5 significantly inhibited tumor growth following 5 injections over 10 days. The size and weight of tumors in the pLXSN-Tum-5 group were lower than those in the saline and pLXSN groups. Furthermore, immunohistochemical analysis with CD31 antibodies indicated that the average microvessel density in the pLXSN-Tum-5 group were significantly lower than that in the saline and pLXSN groups. These results suggested that Tum-5 exerts its antitumor activity by suppressing vascular endothelial cells. The gene fragment of Tum-5 may be developed as an effective inhibitor of angiogenesis and used to treat patients with HCC.

Insulin-like growth factor axis targeting in cancer and tumour angiogenesis - the missing link

Numerous molecular players in the process of tumour angiogenesis have been shown to offer potential for therapeutic targeting. Initially denoted to be involved in malignant transformation and tumour progression, the insulin-like growth factor (IGF) signalling axis has been subject to therapeutic interference, albeit with limited clinical success. More recently, IGFs and their receptors have received attention for their contribution to tumour angiogenesis, which offers novel therapeutic opportunities. Here we review the contribution of this signalling axis to tumour angiogenesis, the mechanisms of resistance to therapy and the interplay with other pro-angiogenic pathways, to offer insight in the renewed interest in the application of IGF axis targeting agents in anti-cancer combination therapies.

Glucose metabolism in gastric cancer: The cutting-edge

Glucose metabolism in gastric cancer cells differs from that of normal epithelial cells. Upregulated aerobic glycolysis (Warburg effect) in gastric cancer meeting the demands of cell proliferation is associated with genetic mutations, epigenetic modification and proteomic alteration. Understanding the mechanisms of aerobic glycolysis may contribute to our knowledge of gastric carcinogenesis. Metabolomic studies offer novel, convenient and practical tools in the search for new biomarkers for early detection, diagnosis, prognosis, and chemosensitivity prediction of gastric cancer. Interfering with the process of glycolysis in cancer cells may provide a new and promising therapeutic strategy for gastric cancer. In this article, we present a brief review of recent studies of glucose metabolism in gastric cancer, with primary focus on the clinical applications of new biomarkers and their potential therapeutic role in gastric cancer.

EMMPRIN regulates tumor growth and metastasis by recruiting bone marrow-derived cells through paracrine signaling of SDF-1 and VEGF

EMMPRIN, a cell adhesion molecule highly expressed in a variety of tumors, is associated with poor prognosis in cancer patients. Mechanistically, EMMPRIN has been characterized to contribute to tumor development and progression by controlling the expression of MMPs and VEGF. In the present study, by using fluorescently labeled bone marrow-derived cells (BMDCs), we found that the down-regulation of EMMPRIN expression in cancer cells reduces tumor growth and metastasis, and is associated with the reduced recruitment of BMDCs. Further protein profiling studies suggest that EMMPRIN controls BMDC recruitment through regulating the secretion of soluble factors, notably, VEGF and SDF-1. We demonstrate that the expression and secretion of SDF-1 in tumor cells are regulated by EMMPRIN. This study reveals a novel mechanism by which EMMPRIN promotes tumor growth and metastasis by recruitment of BMDCs through controlling secretion and paracrine signaling of SDF-1 and VEGF.

The roles of CD147 in the progression of gliomas

Gliomas are characterized by their invasiveness, angiogenesis, glycolysis and poor prognosis. Determining how to inhibit angiogenesis and glycolysis and induce cell death in gliomas is essential to the development of an effective therapy. CD147, a highly glycosylated transmembrane glycoprotein with two Ig-like extracellular domains that belongs to the immunoglobulin superfamily, plays an important role in the regulation of tumor invasiveness, angiogenesis and glycolysis by inducing the secretion of matrix metalloproteinases and vascular endothelial growth factor and by interacting with monocarboxylate transporters. In this review, we first summarize the roles played by CD147 in gliomas and then propose that CD147 may be a complementary prognostic biomarker and a possible therapeutic target for glioma treatment.

CD147 promotes Src-dependent activation of Rac1 signaling through STAT3/DOCK8 during the motility of hepatocellular carcinoma cells

Metastasis is considered a dynamic process in tumor development that is related to abnormal migration and invasion. Tumor cells can move as individual cells in two interconvertible modes: mesenchymal-type and amoeboid. Previously, we reported that the interaction between CD147 and Annexin II can inhibit the amoeboid movement in hepatocellular carcinoma (HCC) cells. However, the mechanism of CD147 involved in mesenchymal movement is still unclear. Notably, our results show overexpression of CD147 led to mesenchymal-type movement in HCC cells. Evidence indicated that the mesenchymal-type cell movement induced by CD147 was Src dependent, as observed by confocal microscopy and Rac1 activity assay. The phosphorylation of Src (pY416-Src) can be up-regulated by CD147, and this regulation is mediated by focal adhesion kinase (FAK). Next, we identified DOCK8 as a GEF for Rac1, a key molecule driving mesenchymal-type movement. We also found that Src promotes STAT3 phosphorylation and STAT3 facilitates DOCK8 transcription, thus enhancing DOCK8 expression and Rac1 activation. This study provides a novel mechanism of CD147 regulating mesenchymal-type movement in HCC cells.

Contradictory Relationships between Cancer and Normal Cells and Implications for Anti-cancer Therapy

Cancer treatment remains a serious problem worldwide. Analysis of the relationship between cancer cells and normal cells reveals that these two share characteristics in contradiction, thus could be analyzed by using contradictory principles. Under the theory of contradictory principles, induction of a dormant state or reversal of cancer cells is an important treatment strategy beyond traditional cytotoxic therapy. Normal cells are also the targets and under the influence of anti-cancer treatments and should be considered during therapy. Findings based on crosstalk between these two cell types may offer opportunities for the development of new biomarkers and therapies.

At the crossroad between obesity and gastric cancer

Obesity has reached epidemic proportions worldwide with disproportionate prevalence in different communities and ethnic groups. Recently, the American Medical Association recognized obesity as a disease, which is a significant milestone that opens the possibilities of treating obesity under standardized health plans. Obesity is an inflammatory disease characterized by elevated levels of biomarkers associated with abnormal lipid profiles, glucose levels, and blood pressure that lead to the onset of metabolic syndrome. Interestingly, inflammatory biomarkers, in particular, have been implicated in the risk of developing several types of cancer. Likewise, obesity has been linked to esophageal, breast, gallbladder, kidney, pancreatic, and colorectal cancers. Thus, there exists a link between obesity status and tumor appearance, which may be associated to the differential levels and the circulating profiles of several inflammatory molecules. For example, mediators of the inflammatory responses in both obesity and gastric cancer risk are the same: pro-inflammatory molecules produced by the activated cells infiltrating the inflamed tissues. These molecules trigger pathways of activation shared by obesity and cancer. Therefore, understanding how these different pathways are modulated would help reduce the impact that both diseases, and their concomitant existence, have on society.

Cell expression patterns of CD147 in N-diethylnitrosamine/phenobarbital-induced mouse hepatocellular carcinoma

Overexpression of CD147/basigin in hepatic cells promotes the progression of hepatocellular carcinoma (HCC). Whether CD147 also expressed in liver non-parenchymal cells and associated with HCC development was unknown. The aim of the study was to explore time-dependent cell expression patterns of CD147 in a widely accepted N-diethylnitrosamine/phenobarbital (DEN/PB)-induced HCC mouse model. Liver samples collected at month 1-12 of post-DEN/PB administration were assessed the localization of CD147 in hepatocytes, endothelial cells, hepatic stellate cells, and macrophages. Immunohistochemistry analysis showed that CD147 was upregulated in liver tumors during month 1-8 of DEN/PB induction. Expression of CD147 was positively correlated with cytokeratin 18, a hepatocyte marker (r = 0.7857, P = 0.0279), CD31 (r = 0.9048, P = 0.0046), an endothelial cell marker, and CD68, a macrophage marker (r = 0.7619, P = 0.0368). A significant correlation was also observed between CD147 and alpha-smooth muscle actin (r = 0.8857, P = 0.0333) at DEN/PB initiation and early stage of tumor formation. Immunofluorescence and fluorescence in situ hybridization showed that CD147 co-expressed with cytokeratin 18, CD31, alpha-smooth muscle actin, and CD68. Moreover, there existed positive correlations between CD147 and microvessel density (r = 0.7857, P = 0.0279), CD147 and Ki-67 (r = 0.9341, P = 0.0022) in the development of DEN/PB-induced HCC. In conclusion, our results demonstrated that CD147 was upregulated in the liver parenchymal and mesenchymal cells and involved in angiogenesis and tumor cell proliferation in the development of DEN/PB-induced HCC.

The biological function and clinical utilization of CD147 in human diseases: a review of the current scientific literature

CD147 or EMMPRIN is a member of the immunoglobulin superfamily in humans. It is widely expressed in human tumors and plays a central role in the progression of many cancers by stimulating the secretion of matrix metalloproteinases (MMPs) and cytokines. CD147 regulates cell proliferation, apoptosis, and tumor cell migration, metastasis and differentiation, especially under hypoxic conditions. CD147 is also important to many organ systems. This review will provide a detailed overview of the discovery, characterization, molecular structure, diverse biological functions and regulatory mechanisms of CD147 in human physiological and pathological processes. In particular, recent studies have demonstrated the potential application of CD147 not only as a phenotypic marker of activated regulatory T cells but also as a potential diagnostic marker for early-stage disease. Moreover, CD147 is recognized as an effective therapeutic target for hepatocellular carcinoma (HCC) and other cancers, and exciting clinical progress has been made in HCC treatment using CD147-directed monoclonal antibodies.

Novel aspects of the liver microenvironment in hepatocellular carcinoma pathogenesis and development

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer that is derived from hepatocytes and is characterised by high mortality rate and poor prognosis. While HCC is driven by cumulative changes in the hepatocyte genome, it is increasingly recognised that the liver microenvironment plays a pivotal role in HCC propensity, progression and treatment response. The microenvironmental stimuli that have been recognised as being involved in HCC pathogenesis are diverse and include intrahepatic cell subpopulations, such as immune and stellate cells, pathogens, such as hepatitis viruses, and non-cellular factors, such as abnormal extracellular matrix (ECM) and tissue hypoxia. Recently, a number of novel environmental influences have been shown to have an equally dramatic, but previously unrecognized, role in HCC progression. Novel aspects, including diet, gastrointestinal tract (GIT) microflora and circulating microvesicles, are now being recognized as increasingly important in HCC pathogenesis. This review will outline aspects of the HCC microenvironment, including the potential role of GIT microflora and microvesicles, in providing new insights into tumourigenesis and identifying potential novel targets in the treatment of HCC.

Adenoviral-mediated gene transfer of insulin-like growth factor 1 enhances wound healing and induces angiogenesis

BACKGROUND

Chronic wounds are characterized by a wound healing and neovascularization deficit. Strategies to increase neovascularization can significantly improve chronic wound healing. Insulin-like growth factor (IGF)-1 is reported to be a keratinocyte mitogen and is believed to induce angiogenesis via a vascular endothelial growth factor (VEGF)-dependent pathway. Using a novel ex vivo human dermal wound model and a diabetic-impaired wound healing murine model, we hypothesized that adenoviral overexpression of IGF-1 (Ad-IGF-1) will enhance wound healing and induce angiogenesis through a VEGF-dependent pathway.

METHODS

Ex vivo: 6-mm full-thickness punch biopsies were obtained from normal human skin, and 3-mm full-thickness wounds were created at the center. Skin explants were maintained at air liquid interface. Db/db murine model: 8-mm full-thickness dorsal wounds in diabetic (db/db) mice were created. Treatment groups in both human ex vivo and in vivo db/db wound models include 1×10(8) particle forming units of Ad-IGF-1 or Ad-LacZ, and phosphate buffered saline (n=4-5/group). Cytotoxicity (lactate dehydrogenase) was quantified at days 3, 5, and 7 for the human ex vivo wound model. Epithelial gap closure (hematoxylin and eosin; Trichrome), VEGF expression (enzyme-linked immunosorbent assay), and capillary density (CD 31+CAPS/HPF) were analyzed at day 7.

RESULTS

In the human ex vivo organ culture, the adenoviral vectors did not demonstrate any significant difference in cytotoxicity compared with phosphate buffered saline. Ad-IGF-1 overexpression significantly increases basal keratinocyte migration, with no significant effect on epithelial gap closure. There was a significant increase in capillary density in the Ad-IGF-1 wounds. However, there was no effect on VEGF levels in Ad-IGF-1 samples compared with controls. In db/db wounds, Ad-IGF-1 overexpression significantly improves epithelial gap closure and granulation tissue with a dense cellular infiltrate compared with controls. Ad-IGF-1 also increases capillary density, again with no significant difference in VEGF levels in the wounds compared with control treatments.

CONCLUSIONS

In two different models, our data demonstrate that adenoviral-mediated gene transfer of IGF-1 results in enhanced wound healing and induces angiogenesis via a VEGF-independent pathway. Understanding the underlying mechanisms of IGF-1 effects on angiogenesis may help produce novel therapeutics for chronic wounds or diseases characterized by a deficit in neovascularization.

Adenoviral-mediated gene transfer of insulin-like growth factor 1 enhances wound healing and induces angiogenesis

BACKGROUND

Chronic wounds are characterized by a wound healing and neovascularization deficit. Strategies to increase neovascularization can significantly improve chronic wound healing. Insulin-like growth factor (IGF)-1 is reported to be a keratinocyte mitogen and is believed to induce angiogenesis via a vascular endothelial growth factor (VEGF)-dependent pathway. Using a novel ex vivo human dermal wound model and a diabetic-impaired wound healing murine model, we hypothesized that adenoviral overexpression of IGF-1 (Ad-IGF-1) will enhance wound healing and induce angiogenesis through a VEGF-dependent pathway.

METHODS

Ex vivo: 6-mm full-thickness punch biopsies were obtained from normal human skin, and 3-mm full-thickness wounds were created at the center. Skin explants were maintained at air liquid interface. Db/db murine model: 8-mm full-thickness dorsal wounds in diabetic (db/db) mice were created. Treatment groups in both human ex vivo and in vivo db/db wound models include 1×10(8) particle forming units of Ad-IGF-1 or Ad-LacZ, and phosphate buffered saline (n=4-5/group). Cytotoxicity (lactate dehydrogenase) was quantified at days 3, 5, and 7 for the human ex vivo wound model. Epithelial gap closure (hematoxylin and eosin; Trichrome), VEGF expression (enzyme-linked immunosorbent assay), and capillary density (CD 31+CAPS/HPF) were analyzed at day 7.

RESULTS

In the human ex vivo organ culture, the adenoviral vectors did not demonstrate any significant difference in cytotoxicity compared with phosphate buffered saline. Ad-IGF-1 overexpression significantly increases basal keratinocyte migration, with no significant effect on epithelial gap closure. There was a significant increase in capillary density in the Ad-IGF-1 wounds. However, there was no effect on VEGF levels in Ad-IGF-1 samples compared with controls. In db/db wounds, Ad-IGF-1 overexpression significantly improves epithelial gap closure and granulation tissue with a dense cellular infiltrate compared with controls. Ad-IGF-1 also increases capillary density, again with no significant difference in VEGF levels in the wounds compared with control treatments.

CONCLUSIONS

In two different models, our data demonstrate that adenoviral-mediated gene transfer of IGF-1 results in enhanced wound healing and induces angiogenesis via a VEGF-independent pathway. Understanding the underlying mechanisms of IGF-1 effects on angiogenesis may help produce novel therapeutics for chronic wounds or diseases characterized by a deficit in neovascularization.

Inhibition effects of gold nanoparticles on proliferation and migration in hepatic carcinoma-conditioned HUVECs

Tumor angiogenesis is a complicated process based upon a sequence of interactions between tumor and vessel endothelial cells. Tumor conditioned medium has been widely used to stimulate endothelial cells in vitro angiogenesis. This work was aimed to investigate the effects of gold nanoparticles (GNPs) on angiogenesis in hepatic carcinoma-conditioned endothelial cells. Human umbilical vein endothelial cells (HUVECs) were cultured with conditioned medium (CM) from the human hepatocarcinoma cell line HepG2 (HepG2-CM), and then treated with different concentrations of GNPs. The effects of GNPs on the viability, migration and active VEGF level of HUVECs were investigated by MTT assay, wound healing assay and transwell chamber assay, and ELISA assay, respectively. The data showed that GNPs significantly inhibited HUVECs proliferation and migration induced by HepG2-CM, and also reduced the levels of active VEGF in the co-culture system. Then, the alterations in morphology and ultrastructure of HUVECs detected by atomic force microscopy (AFM) showed that there appeared obvious pseudopodia, larger membrane particle sizes and much rougher surface in HUVECs after HepG2-CM treatment, which were all reversed after GNPs treatment. Changes in cytoskeleton of HUVECs determined by immunocytochemistry demonstrated that GNPs treatment remarkably inhibited the activation effect of HepG2-CM on HUVECs, which was associated with the disruption of actin filaments induced by GNPs. This study indicates that GNPs can significantly inhibit HepG2-CM activated endothelial cell proliferation and migration through down-regulation of VEGF activity and disruption of cell morphology, revealing the potential applications of GNPs as antiangiogenic agent for the treatment of hepatic carcinoma.

3D in vitro tissue models and their potential for drug screening

INTRODUCTION

The development of one standard, simplified in vitro three-dimensional tissue model suitable to biological and pathological investigation and drug-discovery may not yet be feasible, but standardized models for individual tissues or organs are a possibility. Tissue bioengineering, while concerned with finding methods of restoring functionality in disease, is developing technology that can be miniaturized for high throughput screening (HTS) of putative drugs. Through collaboration between biologists, physicists and engineers, cell-based assays are expanding into the realm of tissue analysis. Accordingly, three-dimensional (3D) micro-organoid systems will play an increasing role in drug testing and therapeutics over the next decade. Nevertheless, important hurdles remain before these models are fully developed for HTS.

AREAS COVERED

We highlight advances in the field of tissue bioengineering aimed at enhancing the success of drug candidates through pre-clinical optimization. We discuss models that are most amenable to high throughput screening with emphasis on detection platforms and data modeling.

EXPERT OPINION

Modeling 3D tissues to mimic in-vivo architecture remains a major challenge. As technology advances to provide novel methods of HTS analysis, so do potential pitfalls associated with such models and methods. We remain hopeful that integration of biofabrication with HTS will significantly reduce attrition rates in drug development.

Azathioprine desensitizes liver cancer cells to insulin-like growth factor 1 and causes apoptosis when it is combined with bafilomycin A1

Hepatoblastoma is a primary liver cancer that affects children, due to the sensitivity of this tumor to insulin-like growth factor 1 (IGF-1). In this paper we show that azathioprine (AZA) is capable of inhibiting IGF1-mediated signaling cascade in HepG2 cells. The efficiency of AZA on inhibition of proliferation differs in the evaluated cell lines as follows: HepG2 (an experimental model of hepatoblastoma)>Hep3B (derived from a hepatocellular carcinoma)>HuH6 (derived from a hepatoblastoma)>>HuH7 (derived from a hepatocellular carcinoma)=Chang Liver cells (a non-malignant cellular model). The effect of AZA in HepG2 cells has been proven to derive from activation of Ras/ERK/TSC2, leading to activation of mTOR/p70S6K in a sustained manner. p70S6K phosphorylates IRS-1 in serine 307 which leads to the uncoupling between IRS-1 and p85 (the regulatory subunit of PI3K) and therefore causing the lack of response of HepG2 to IGF-1. As a consequence, proliferation induced by IGF-1 is inhibited by AZA and autophagy increases leading to senescence of HepG2 cells. Our results suggest that AZA induces the autophagic process in HepG2 activating senescence, and driving to deceleration of cell cycle but not to apoptosis. However, when simultaneous to AZA treatment the autophagy was inhibited by bafilomycin A1 and the degradation of regulatory proteins of cell cycle (e.g. Rb, E2F, and cyclin D1) provoked apoptosis. In conclusion, AZA induces resistance in hepatoblastoma cells to IGF-1, which leads to autophagy activation, and causes apoptosis when it is combined with bafilomycin A1. We are presenting here a novel mechanism of action of azathioprine, which could be useful in treatment of IGF-1 dependent tumors, especially in its combination with other drugs.

Annexin A2 promotes the migration and invasion of human hepatocellular carcinoma cells in vitro by regulating the shedding of CD147-harboring microvesicles from tumor cells

It has been reported that Annexin A2 (ANXA2) is up-regulated in hepatocellular carcinoma (HCC), but the roles of ANXA2 in the migration and invasion of HCC cells have not been determined. In this study, we found that ANXA2-specific siRNA (si-ANXA2) significantly inhibited the migration and invasion of HCC cells co-cultured with fibroblasts in vitro. In addition, the production of MMP-2 by fibroblasts cultured in supernatant collected from si-ANXA2-transfected HCC cells was notably down-regulated. ANXA2 was also found to be co-localized and co-immunoprecipitated with CD147. Further investigation revealed that the expression of ANXA2 in HCC cells affected the shedding of CD147-harboring membrane microvesicles, acting as a vehicle for CD147 in tumor-stromal interactions and thereby regulating the production of MMP-2 by fibroblasts. Together, these results suggest that ANXA2 enhances the migration and invasion potential of HCC cells in vitro by regulating the trafficking of CD147-harboring membrane microvesicles.

Meeting the challenge of ascites in ovarian cancer: new avenues for therapy and research

Malignant ascites presents a considerable clinical challenge to the management of ovarian cancer, but also provides a wealth of opportunities for translational research. The accessibility of ascitic fluid and its cellular components make it an excellent source of tumour tissue for the investigation of prognostic and predictive biomarkers, pharmacodynamic markers and for molecular profiling analysis. In this Opinion article, we discuss recent advances in our understanding of its pathophysiology, the development of new methods to characterize its molecular features and how these findings can be used to improve the treatment of malignant ascites, particularly in the context of ovarian cancer.

Obesity-driven inflammation and cancer risk: role of myeloid derived suppressor cells and alternately activated macrophages

During carcinogenesis, tumors induce dysfunctional development of hematopoietic cells. Myeloid lineage cells, in the form of myeloid derived suppressor cells (MDSCs) and alternatively polarized M2 macrophages, influence almost all types of cancers by regulating diverse facets of immunosuppression, angiogenesis, cell proliferation, growth and metastasis. One-third of Americans are obese, and accumulating evidence suggests that obesity is a risk factor for various cancers. However, the relationship between these immune players and obesity are not well-described. In this review, we evaluate potential mechanisms through which different aspects of obesity, namely insulin resistance, increased estrogen, adiposity and low grade chronic inflammation from adipose tissue macrophages, may coalesce to promote MDSC induction and M2 macrophage polarization, thereby facilitating cancer development. Detailed understanding of the interplay between obesity and myeloid mediated immunosuppression may provide novel avenues for therapeutic targeting, with the goal to reduce the challenge obesity presents towards gains made in cancer outcomes.