Anti-angiogenesis and metastasis: a tumour and stromal cell alliance

Identification and validation of a novel 17 coagulation-related genes signature for predicting prognostic risk in colorectal cancer

Background

Patients with colorectal cancer commonly experience disturbances in coagulation homeostasis. Activation of the coagulation system contributes to cancer-associated thrombosis as the second risk factor for death in cancer patients. This study intended to discover coagulation-related genes and construct a risk model for colorectal cancer patients' prognosis.

Methods

Coagulation-related genes were identified by searching coagulation-related pathways in the Molecular Signatures Database. Transcriptomic data and clinical data were downloaded from the Cancer Genome Atlas and Gene Expression Omnibus datasets. Univariate Cox and backward stepwise regression were utilized to identify prognosis-related genes and construct a predictive risk model for the training cohort. Next, survival analysis determines the risk model's predictive power, correlation with clinicopathological characteristics, and nomogram. Additionally, we characterized the variances in immune cell infiltration, somatic mutations, immune checkpoint molecules, biological functions, and drug sensitivity between the high- and low-score patients.

Result

Eight hundred forty-five genes were obtained by searching the theme term "coagulation" after de-duplication. After univariate regression analysis, 69 genes correlated with prognosis were obtained from the Cancer Genome Atlas dataset. A signature consisting of 17 coagulation-related genes was established through backward stepwise regression. The Kaplan-Meier curve indicated a worse prognosis for high-score patients. Time-dependent receiver operating characteristic curve analysis demonstrated high accuracy in predicting overall survival. Further, the results were validated by two independent datasets (GSE39582 and GSE17536). Combined with clinicopathological characteristics, the risk model was proven to be an independent prognostic factor to predict poor pathological status and worse prognosis. Furthermore, high-score patients had significantly higher stromal cell infiltration. Low-score patients were associated with high infiltration of resting memory CD4+ T cells, activated CD4+ T cells, and T follicular helper cells. The low-score patients exhibited increased expression of immune checkpoint genes, and this might be relevant to their better prognosis. High-score patients exhibited lower IC50 values of Paclitaxel, Rapamycin, Temozolomide, Cyclophosphamide, etc. The differential signaling pathways mainly involve the calcium signaling pathway and the neuroactive ligand-receptor interaction. Lastly, a nomogram was constructed and showed a good prediction.

Conclusion

The prognostic signature of 17 coagulation-related genes had significant prognostic value for colorectal cancer patients. We expect to improve treatment modalities and benefit more patients through research on molecular features.

Progressions of the correlation between lipid metabolism and immune infiltration characteristics in gastric cancer and identification of BCHE as a potential biomarker

Background

Globally, gastric cancer (GC) is a category of prevalent malignant tumors. Its high occurrence and fatality rates represent a severe threat to public health. According to recent research, lipid metabolism (LM) reprogramming impacts immune cells' ordinary function and is critical for the onset and development of cancer. Consequently, the article conducted a sophisticated bioinformatics analysis to explore the potential connection between LM and GC.

Methods

We first undertook a differential analysis of the TCGA queue to recognize lipid metabolism-related genes (LRGs) that are differentially expressed. Subsequently, we utilized the LASSO and Cox regression analyses to create a predictive signature and validated it with the GSE15459 cohort. Furthermore, we examined somatic mutations, immune checkpoints, tumor immune dysfunction and exclusion (TIDE), and drug sensitivity analyses to forecast the signature's immunotherapy responses.

Results

Kaplan-Meier (K-M) curves exhibited considerably longer OS and PFS (p<0.001) of the low-risk (LR) group. PCA analysis and ROC curves evaluated the model's predictive efficacy. Additionally, GSEA analysis demonstrated that a multitude of carcinogenic and matrix-related pathways were much in the high-risk (HR) group. We then developed a nomogram to enhance its clinical practicality, and we quantitatively analyzed tumor-infiltrating immune cells (TIICs) using the CIBERSORT and ssGSEA algorithms. The low-risk group has a lower likelihood of immune escape and more effective in chemotherapy and immunotherapy. Eventually, we selected BCHE as a potential biomarker for further research and validated its expression. Next, we conducted a series of cell experiments (including CCK-8 assay, Colony formation assay, wound healing assay and Transwell assays) to prove the impact of BCHE on gastric cancer biological behavior.

Discussion

Our research illustrated the possible consequences of lipid metabolism in GC, and we identified BCHE as a potential therapeutic target for GC. The LRG-based signature could independently forecast the outcome of GC patients and guide personalized therapy.

Brassica-derived isothiocyanates as anticancer therapeutic agents and their nanodelivery

The isothiocyanates (ITCs) derived from the precursor glucosinolate molecules present in Brassica vegetables are bioactive organo-sulfur compounds with numerous pharmacologically important properties such as antioxidant, antiinflammatory, antimicrobial, and anticancer. Over the years, ITCs have been the focus of several research investigations associated with cancer treatment. Due to their potent chemo-preventive action, ITCs have been considered to be promising therapeutics for cancer therapy in place of the already existing conventional anticancer drugs. However, their wide spread use at the clinical stage is greatly restricted due to several factors such as low solubility in an aqueous medium, low bioavailability, low stability, and hormetic effect. To overcome these hindrances, nanotechnology can be exploited to develop nano-scale delivery systems that have the potential to enhance stability, and bioavailability and minimize the hermetic effect of ITCs.

Promalignant effects of antiangiogenics in the tumor microenvironment

Antiangiogenic therapies are considered a promising strategy against solid tumors. Their aim is to inhibit the formation of new blood vasculature, thereby reducing the oxygen and nutrient supply to prevent further tumor growth and spreading. However, the strategy has seen limitations, as survival benefits are modest and often accompanied with increased tumor aggressiveness in form of invasion and metastasis. Antiangiogenic induced changes in the tumor microenvironment, such as hypoxia, mechanical stress or extracellular acidification can activate different receptors of tumoral and stromal cells and induce an extensive remodeling of the entire tumor microenvironment, with the overall goal to invade nearby tissues and regain access to the vasculature. In this regard, receptor tyrosine kinases have been studied intensively and especially the inhibition of c-Met has given promising results, characterized by a reduction in invasiveness and prolonged survival. Receptors that sense changes in the extracellular matrix like integrins or proteoglycans can also induce downstream signaling that stimulates the expression of remodeling factors such as new matrix components, enzymes or chemoattractants. Targeting multiple receptors and sensors of cancer cells simultaneously might represent an effective second line treatment that prevents the formation of malignant side effects.

Cuproptosis regulator-mediated patterns associated with immune infiltration features and construction of cuproptosis-related signatures to guide immunotherapy

Background

Liver hepatocellular carcinoma (HCC) is a prevalent cancer that lacks a sufficiently efficient approach to guide immunotherapy. Additionally, cuproptosis is a recently identified regulated cell death program that is triggered by copper ionophores. However, its possible significance in tumor immune cell infiltration is still unclear.

Methods

Cuproptosis subtypes in HCC were identified using unsupervised consensus cluster analysis based on 10 cuproptosis regulators expressions, and a cuproptosis-related risk signature was generated using univariate and LASSO Cox regression and validated using the ICGC data. Moreover, the relationship between signature and tumor immune microenvironment (TME) was studied through tumor immunotherapy responsiveness, immune cell infiltration, and tumor stem cell analysis. Finally, clinical specimens were analyzed using immunohistochemistry to verify the expression of the three genes in the signature.

Results

Two subtypes of cuproptosis regulation were observed in HCC, with different immune cell infiltration features. Genes expressed differentially between the two cuproptosis clusters in the TCGA were determined and used to construct a risk signature that was validated using the ICGC cohort. Greater immune and stromal cell infiltration were observed in the high-risk group and were associated with unfavorable prognosis. Elevated risk scores were linked with higher RNA stemness scores (RNAss) and tumor mutational burden (TMB), together with a greater likelihood of benefitting from immunotherapy.

Conclusion

It was found that cuproptosis regulatory patterns may play important roles in the heterogeneity of immune cell infiltration. The risk signature associated with cuproptosis can assess each patient's risk score, leading to more individualized and effective immunotherapy.

Therapeutic Potential of Natural Products in the Treatment of Renal Cell Carcinoma: A Review

Renal cell carcinoma (RCC) is a common cancer of the urinary system. The potential therapeutic effects of certain natural products against renal cell carcinoma have been reported both in vivo and in vitro, but no reviews have been published classifying and summarizing the mechanisms of action of various natural products. In this study, we used PubMed and Google Scholar to collect and screen the recent literature on natural products with anti-renal-cancer effects. The main mechanisms of action of these products include the induction of apoptosis, inhibition of angiogenesis, inhibition of metastasis and reduction of drug resistance. In total, we examined more than 30 natural products, which include kahweol acetate, honokiol, englerin A and epigallocatechin-3-gallate, among others, have demonstrated a variety of anti-renal-cancer effects. In conclusion, natural products may have a wider application in kidney cancer than previously believed and are potential candidates for treatment in RCC.

N6-Methyladenosine Regulator-Mediated Immue Patterns and Tumor Microenvironment Infiltration Characterization in Glioblastoma

Background

Epigenetic modifications, according to emerging evidence, perform a critical role for cellular immune response and tumorigenesis. Nonetheless, the role of N6-methyladenosine modification in shaping of the glioblastoma tumor microenvironment is unknown.

Methods

N6-methyladenosine(m6A) methylation patterns in GBM patients were evaluated via multiple omics analysis of 15 m6A regulators and systematically correlated with tumor immune features. For quantification of N6-methyladenosine methylation patterns of individual patients, GM-score was developed and correlated with clinical and immunological characteristics.

Results

Glioblastoma has two different m6A methylation patterns that are strongly associated with TME characteristics, tumor subtype, immunotherapy response, and patient prognosis. High-GM-score is associated with an immune tolerance phenotype dominated by the IDH1 wild molecular subtype and the Mesenchymal tissue subtype, as well as a high infiltration of immune cells and stromal cells and a poor prognosis. Furthermore, despite higher immune checkpoint expression, individuals with a high-GM-score have a poorer response to anti-CTLA4 immunotherapy regimens due to T-cells dysfunctional. Low-GM-score individuals had an immunodeficient phenotype dominated by IDH mutant molecular subtypes and Proneural tissue subtypes, with less immune cell infiltration and a better prognosis. Furthermore, patients with low-GM-scores had higher microsatellite instability (MSI) and t-cell exclusion scores, as well as a better response to anti-CTLA4 immunotherapy regimens.

Conclusion

This study demonstrated that m6A modification patterns play an important role in the shaping of TME complexity and diversity. The GM-score could identify m6A modification patterns in individual patients, resulting in a more personalization and efficacious anti-tumor immunotherapy strategy.

Immunotherapy Resistance in Glioblastoma

Glioblastoma is the most common malignant primary brain tumor in adults. Despite treatment consisting of surgical resection followed by radiotherapy and adjuvant chemotherapy, survival remains poor at a rate of 26.5% at 2 years. Recent successes in using immunotherapies to treat a number of solid and hematologic cancers have led to a growing interest in harnessing the immune system to target glioblastoma. Several studies have examined the efficacy of various immunotherapies, including checkpoint inhibitors, vaccines, adoptive transfer of lymphocytes, and oncolytic virotherapy in both pre-clinical and clinical settings. However, these therapies have yielded mixed results at best when applied to glioblastoma. While the initial failures of immunotherapy were thought to reflect the immunoprivileged environment of the brain, more recent studies have revealed immune escape mechanisms created by the tumor itself and adaptive resistance acquired in response to therapy. Several of these resistance mechanisms hijack key signaling pathways within the immune system to create a protumoral microenvironment. In this review, we discuss immunotherapies that have been trialed in glioblastoma, mechanisms of tumor resistance, and strategies to sensitize these tumors to immunotherapies. Insights gained from the studies summarized here may help pave the way for novel therapies to overcome barriers that have thus far limited the success of immunotherapy in glioblastoma.

Challenges and Prospects for Designer T and NK Cells in Glioblastoma Immunotherapy

Glioblastoma (GBM) is the most prevalent, aggressive primary brain tumour with a dismal prognosis. Treatment at diagnosis has limited efficacy and there is no standardised treatment at recurrence. New, personalised treatment options are under investigation, although challenges persist for heterogenous tumours such as GBM. Gene editing technologies are a game changer, enabling design of novel molecular-immunological treatments to be used in combination with chemoradiation, to achieve long lasting survival benefits for patients. Here, we review the literature on how cutting-edge molecular gene editing technologies can be applied to known and emerging tumour-associated antigens to enhance chimeric antigen receptor T and NK cell therapies for GBM. A tight balance of limiting neurotoxicity, avoiding tumour antigen loss and therapy resistance, while simultaneously promoting long-term persistence of the adoptively transferred cells must be maintained to significantly improve patient survival. We discuss the opportunities and challenges posed by the brain contexture to the administration of the treatments and achieving sustained clinical responses.

Potential Roles of Iridoid Glycosides and Their Underlying Mechanisms against Diverse Cancer Growth and Metastasis: Do They Have an Inhibitory Effect on Cancer Progression?

Iridoids are glycosides found in plants, having inherent roles in defending them against infection by viruses and microorganisms, and in the rapid repair of damaged areas. The emerging roles of iridoid glycosides on pharmacological properties have aroused the curiosity of many researchers, and studies undertaken indicate that iridoid glycosides exert inhibitory effects in numerous cancers. This review focuses on the roles and the potential mechanism of iridoid glycosides at each stage of cancer development such as proliferation, epithelial mesenchymal transition (EMT), migration, invasion and angiogenesis. Overall, the reviewed literature indicates that iridoid glycosides inhibit cancer growth by inducing cell cycle arrest or by regulating apoptosis-related signaling pathways. In addition, iridoid glycosides suppress the expression and activity of matrix metalloproteinases (MMPs), resulting in reduced cancer cell migration and invasiveness. The antiangiogenic mechanism of iridoid glycosides was found to be closely related to the transcriptional regulation of pro-angiogenic factors, i.e., vascular endothelial growth factors (VEGFs) and cluster of differentiation 31 (CD31). Taken together, these results indicate the therapeutic potential of iridoid glycosides to alleviate or prevent rapid cancer progression and metastasis.

Immune Escape in Glioblastoma Multiforme and the Adaptation of Immunotherapies for Treatment

Glioblastoma multiforme (GBM) is the most frequently occurring primary brain tumor and has a very poor prognosis, with only around 5% of patients surviving for a period of 5 years or more after diagnosis. Despite aggressive multimodal therapy, consisting mostly of a combination of surgery, radiotherapy, and temozolomide chemotherapy, tumors nearly always recur close to the site of resection. For the past 15 years, very little progress has been made with regards to improving patient survival. Although immunotherapy represents an attractive therapy modality due to the promising pre-clinical results observed, many of these potential immunotherapeutic approaches fail during clinical trials, and to date no immunotherapeutic treatments for GBM have been approved. As for many other difficult to treat cancers, GBM combines a lack of immunogenicity with few mutations and a highly immunosuppressive tumor microenvironment (TME). Unfortunately, both tumor and immune cells have been shown to contribute towards this immunosuppressive phenotype. In addition, current therapeutics also exacerbate this immunosuppression which might explain the failure of immunotherapy-based clinical trials in the GBM setting. Understanding how these mechanisms interact with one another, as well as how one can increase the anti-tumor immune response by addressing local immunosuppression will lead to better clinical results for immune-based therapeutics. Improving therapeutic delivery across the blood brain barrier also presents a challenge for immunotherapy and future therapies will need to consider this. This review highlights the immunosuppressive mechanisms employed by GBM cancers and examines potential immunotherapeutic treatments that can overcome these significant immunosuppressive hurdles.

Mechanisms Underlying Biological Effects of Cruciferous Glucosinolate-Derived Isothiocyanates/Indoles: A Focus on Metabolic Syndrome

An inverse correlation between vegetable consumption and the incidence of cancer has long been described. This protective effect is stronger when cruciferous vegetables are specifically consumed. The beneficial properties of vegetables are attributed to their bioactive components like fiber, antioxidants vitamins, antioxidants, minerals, and phenolic compounds. Cruciferous vegetables contain all these molecules; however, what makes them different are their sulfurous components, called glucosinolates, responsible for their special smell and taste. Glucosinolates are inactive biologically in the organism but are hydrolyzed by the enzyme myrosinase released as a result of chewing, leading to the formation of active derivatives such as isothiocyanates and indoles. A considerable number of in vitro and in vivo studies have reported that isothiocyanates and indoles elicit chemopreventive potency through multiple mechanisms that include modulation of phases I and II detoxification pathway enzymes, regulation of cell cycle arrest, and control of cell growth, induction of apoptosis, antioxidant activity, anti-angiogenic effects, and epigenetic regulation. Nuclear erythroid 2-related factor 2 (Nrf2) and Nuclear factor-κB (NF-κB) are key and central regulators in all these processes with a main role in oxidative stress and inflammation control. It has been described that isothiocyanates and indoles regulate their activity directly and indirectly. Today, the metabolic syndrome (central obesity, insulin resistance, hyperlipidemia, and hypertension) is responsible for a majority of deaths worldwide. All components of metabolic syndrome are characterized by chronic inflammation with deregulation of the PI3K/AKT/mTOR, MAPK/EKR/JNK, Nrf2, and NF-κB signaling pathways. The effects of GLSs derivatives controlling these pathways have been widely described in relation to cancer. Changes in food consumption patterns observed in the last decades to higher consumption of ultra-processed foods, with elevation in simple sugar and saturated fat contents and lower consumption of vegetables and fruits have been directly correlated with metabolic syndrome prevalence. In this review, it is summarized the knowledge regarding the mechanisms by which cruciferous glucosinolate derivatives (isothiocyanates and indoles) directly and indirectly regulate these pathways. However, the review places a special focus on the knowledge of the effects of glucosinolates derivatives in metabolic syndrome, since this has not been reviewed before.

The Proportion of Tumour-Stroma in Metastatic Lymph Nodes is An Accurately Prognostic Indicator of Poor Survival for Advanced-Stage Colon Cancers

The importance of tumour microenvironment in tumour behaviour has now become clearer. This study aimed to determine the prognostic effect of the proportion of tumour-stroma (PTS) in metastatic lymph nodes of advanced-stage colon cancers (CCs). We investigated PTS in positive lymph nodes of stage III-IV CC patients who underwent surgical treatment between 2004 and 2014. We used a standard approach in methodology. PTS was significantly associated with prognostic factors in the metastatic lymph nodes (perineural invasion [p = 0.031], lymphatic invasion [p = 0.032], invasive margin [p = 0.043], advanced pT [p = 0.020], and margin involvement [p = 0.034]). In addition, the correlations between PTS estimates (R = 0.704 to 0.617, p < 0.001), the reproducibility of the research (Κappa = 0.72-0.68) and the usefulness of the cut-off value (ROC: 50.33%; AUC = 0.752 [0.667-0.857]) were successful. In univariate analysis, 5-year survival was poor for RFS (p < 0.001), OS (p = 0.001) and LR (p = 0.013) in high PTS patients. Multivariate analysis confirmed that high PTS was an independent worse parameter for RFS (HR = 1.32, 95% CI: 1.17-2.55, p = 0.001) and OS (HR = 1.37, 95% CI: 1.25-1 - 2.56, p = 0.009). In this study, we showed that high PTS in metastatic lymph nodes was a successful prognostic marker for advanced-stage CCs. Also, the standard approach we used for the methodology was successful.

Multiple Targets Directed Multiple Ligands: An In Silico and In Vitro Approach to Evaluating the Effect of Triphala on Angiogenesis

Angiogenesis is critical in both physiological and pathological conditions and targeting angiogenesis is a promising strategy for the development of therapies against cancer; however, cells develop resistance to anti-angiogenic therapy, necessitating a more effective strategy. Natural medicines have been used in anti-cancer therapy for many years, but the mechanisms behind these have not generally been explored. Triphala churna (THL), an Indian ayurvedic herbal formulation made from the dried fruits of three medicinal plants, is used as a herbal drug for the treatment of various diseases, including cancer. THL contains over fifteen phytochemicals with different pharmacological effects, especially inhibition of tumor progression. In this study, we examined the effect of these compounds against different targets using docking and in vitro studies. Results showed that THL has a prediction efficacy of (−)436.7, and it inhibited angiogenesis by blocking multiple components of the VEGF/VEGFR2 signaling pathway. The anti-angiogenic effect was mediated by the combined effect of the two top ranked phytochemicals, punicalagin (−424.8) and chebulagic acid (−414.8). The new approach developed in this study to determine the potential efficacy of herbal formulation could be a useful strategy to assess the efficacy of different herbal formulations.

Tumour vessel remodelling: new opportunities in cancer treatment

Tumour growth critically depends on a supportive microenvironment, including the tumour vasculature. Tumour blood vessels are structurally abnormal and functionally anergic which limits drug access and immune responses in solid cancers. Thus, tumour vasculature has been considered an attractive therapeutic target for decades. However, with time, anti-angiogenic therapy has evolved from destruction to structural and functional rehabilitation as understanding of tumour vascular biology became more refined. Vessel remodelling or normalisation strategies which alleviate hypoxia are now coming of age having been shown to have profound effects on the tumour microenvironment. This includes improved tumour perfusion, release from immune suppression and lower metastasis rates. Nevertheless, clinical translation has been slow due to challenges such as the transient nature of current normalisation strategies, limited in vivo monitoring and the heterogeneity of primary and/or metastatic tumour environments, calling for more tailored approaches to vascular remodelling. Despite these setbacks, harnessing vascular plasticity provides unique opportunities for anti-cancer combination therapies in particular anti-angiogenic immunotherapy which are yet to reach their full potential.

The Role of Isothiocyanates as Cancer Chemo-Preventive, Chemo-Therapeutic and Anti-Melanoma Agents

Many studies have shown evidence in support of the beneficial effects of phytochemicals in preventing chronic diseases, including cancer. Among such phytochemicals, sulphur-containing compounds (e.g., isothiocyanates (ITCs)) have raised scientific interest by exerting unique chemo-preventive properties against cancer pathogenesis. ITCs are the major biologically active compounds capable of mediating the anticancer effect of cruciferous vegetables. Recently, many studies have shown that a higher intake of cruciferous vegetables is associated with reduced risk of developing various forms of cancers primarily due to a plurality of effects, including (i) metabolic activation and detoxification, (ii) inflammation, (iii) angiogenesis, (iv) metastasis and (v) regulation of the epigenetic machinery. In the context of human malignant melanoma, a number of studies suggest that ITCs can cause cell cycle growth arrest and also induce apoptosis in human malignant melanoma cells. On such basis, ITCs could serve as promising chemo-therapeutic agents that could be used in the clinical setting to potentiate the efficacy of existing therapies.

Photodynamic Therapy Mediated by Aloe-Emodin Inhibited Angiogenesis and Cell Metastasis Through Activating MAPK Signaling Pathway on HUVECs

Photodynamic therapy is a clinically used, minimally invasive therapeutic procedure that involves the application of photosensitizers which can locate in target cells and so be irradiated at a corresponding wavelength. Laser light irradiation activation of photosensitizers generates free reactive oxygen species, which induces selective cytotoxic activity in target cells. Within recent years, aloe-emodin as a photosensitizer has been successfully applied in photodynamic therapy applications. Angiogenesis plays an important role in tumor growth and metastasis; thus, the development of a novel target treatment for angiogenesis is essential in order to improve treatment therapeutics for cancer treatment. An essential step in angiogenesis involves the formation of tube-like structures during matrix degradation, rearrangement, and apoptosis of endothelial cells. In the present study, we investigated the mechanisms of photocytotoxicity induced by aloe-emodin in human umbilical vein endothelial cells. Analysis of cell proliferation results noted a significant decrease in cultured cells which received various concentrations of aloe-emodin and photodynamic therapy–induced light doses. Additionally, mitochondrial mechanisms of apoptotic cell death were observed in aloe-emodin photodynamic therapy–treated cells, as tube formation assays noted angiogenesis suppression after treatment. The capacity of migration and invasion of human umbilical vein endothelial cells was measured using the transwell assay and demonstrated that aloe-emodin photodynamic therapy significantly inhibited the migration and invasion of human umbilical vein endothelial cells. The expression of p38, extracellular signal-regulated kinase, the c-Jun N-terminal kinases, and vascular endothelial growth factor suggested that the cellular metastasis was related to mitogen-activated protein kinase signal pathway. Furthermore, disorganization of F action cytoskeleton components was observed after aloe-emodin photodynamic therapy. Overall, the findings from this study suggest that aloe-emodin photodynamic therapy inhibited angiogenesis and cellular metastasis in human umbilical vein endothelial cells by activating the mitogen-activated protein kinase apoptotic signaling cell death pathway.

Roles of Myeloid-Derived Suppressor Cells in Cancer Metastasis: Immunosuppression and Beyond

Metastasis is the direst face of cancer, and it is not a feature solely dependent on cancer cells; however, a complex interaction between cancer cells and host causes this process. Investigating the mechanisms of metastasis can lead to its control. Myeloid-derived suppressor cells (MDSCs) are key components of tumor microenvironment that favor cancer progression. These cells result from altered myelopoiesis in response to the presence of tumor. The most recognized function of MDSCs is suppressing anti-tumor immune responses. Strikingly, these cells are among important players in cancer dissemination and metastasis. They can exert their effect on metastatic process by affecting anti-cancer immunity, epithelial-mesenchymal transition, cancer stem cell formation, angiogenesis, establishing premetastatic niche, and supporting cancer cell survival and growth in metastatic sites. In this article, we review and discuss the mechanisms by which MDSCs contribute to cancer metastasis.

Tumor microenvironmental factors have prognostic significances in advanced gastric cancer

Tumor microenvironment is important in the progression and survival of cancer cells. We evaluated the prognostic significance of tumor stroma percentage (TSP), Klintrup-Mäkinen (KM) grade, which reflects the density of inflammatory cells of the tumor, and Glasgow microenvironment score (GMS), a combination of TSP and KM grade, in advanced gastric cancers. A total of 196 pT3 and pT4 gastric cancers were histologically evaluated using TSP, KM grade, and GMS. These were correlated with other clinicopathologic factors including patients' survival. High TSP (78 cases), low KM grade (124 cases), and higher GMS (score 0, 72 cases; 1, 53 cases; and 2, 71 cases) were correlated with poor differentiation, diffuse type, presence of lymphovascular invasion, perineural invasion, and lymph node metastasis. High TSP was significantly correlated with low KM grade (p < 0.001). High TSP (HR, 3.079, 95% CI, 1.612-5.883, p = 0.001), low KM grade (3.201, 1.774-5.776, p < 0.001), and higher GMS (12.274, 3.684-40.895, p < 0.001) were independent poor prognostic factors. TSP, KM grade, and GMS are significantly associated with clinicopathologic behavior and patients' survival. Assessing these factors is a feasible and cost-effective way to identify tumor microenvironment with different biological features and prognosis of gastric cancer patients.

RNA activating-double stranded RNA targeting flt-1 promoter inhibits endothelial cell proliferation through soluble FLT-1 upregulation

Short-activating RNA (saRNA), which targets gene promoters, has been shown to increase the target gene expression. In this study, we describe the use of an saRNA (Flt a-1) to target the flt-1 promoter, leading to upregulation of the soluble isoform of Flt-1 and inhibition of angiogenesis. We demonstrate that Flt a-1 increased sFlt-1 mRNA and protein levels, while reducing VEGF expression. This was associated with suppression of human umbilical vascular endothelial cell (HUVEC) proliferation and cell cycle arrest at the G0/G1 phase. HUVEC migration and tube formation were also suppressed by Flt a-1. An siRNA targeting Flt-1 blocked the effects of Flt a-1. Flt a-1 effects were not mediated via argonaute proteins. However, trichostatin A and 5'-deoxy-5'-(methylthio) adenosine inhibited Flt a-1 effects, indicating that histone acetylation and methylation are mechanistically involved in RNA activation of Flt-1. In conclusion, RNA activation of sFlt-1 can be used to inhibit angiogenesis.

Current Challenges of Cancer Anti-angiogenic Therapy and the Promise of Nanotherapeutics

With growing interest in cancer therapeutics, anti-angiogenic therapy has received considerable attention and is widely administered in several types of human cancers. Nonetheless, this type of therapy may induce multiple signaling pathways compared with cytotoxics and lead to worse outcomes in terms of resistance, invasion, metastasis, and overall survival (OS). Moreover, there are important challenges that limit the translation of promising biomarkers into clinical practice to monitor the efficiency of anti-angiogenic therapy. These pitfalls emphasize the urgent need for discovering alternative angiogenic inhibitors that target multiple angiogenic factors or developing a new drug delivery system for the current inhibitors. The great advantages of nanoparticles are their ability to offer effective routes that target the biological system and regulate different vital processes based on their unique features. Limited studies so far have addressed the effectiveness of nanoparticles in the normalization of the delicate balance between stimulating (pro-angiogenic) and inhibiting (anti-angiogenic) factors. In this review, we shed light on tumor vessels and their microenvironment and consider the current directions of anti-angiogenic and nanotherapeutic treatments. To the best of our knowledge, we consider an important effort in the understanding of anti-angiogenic agents (often a small volume of metals, nonmetallic molecules, or polymers) that can control the growth of new vessels.

The prophylactic and therapeutic effects of Momordica charantia methanol extract through controlling different hallmarks of the hepatocarcinogenesis

Inspite of the wide facilities for controlling cancer growth, there are little drugs to inhibit its metastasis or prevent its angiogenesis. Discovering such natural or synthetic multi-targeted agent that might strike different targets is considered as a vital goal for tumor controlling. In a previous study, the chemoprotective effect of methanol extract of Momordicacharantia (MEMC) on albino western rats bearing hepatocarcinogenesis was evaluated. The mechanism by which MEMC exert its anticancer properties was unknown. Therefore, we aimed in this study to investigate the possible role of MEMC as anti-proliferative, anti-angiogenic and anti-metastatic agent to exert its chemoprotective effect. The study was conducted on sixty albino western rats divided into six groups, 10 rats each. Diethylnitrosamine (DENA) was injected intraperitoneally (i.p.) at a dose of 200 mg/kg body weight once, 2 weeks later rats were received carbon tetrachloride (CCl₄₎ subcutaneously (3 ml/kg/week) continued for 10 weeks. MEMC was orally produced to rats (40 mg/kg) alone, as well as before, at the same time and after DENA injection. Cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), caspase-3,-8 (Casp-3,-8), histone deacetylase (HDAC) and matrixmetalloproteinases-2,-9 (MMP-2,-9) were evaluated. MEMC treatment significantly decreased Cox-2, VEGF, HDAC and MMP-2,-9 and increased Casp-3,-8 as compared to DENAgroup,which demonstrated that the anticancer effect of MEMC may be through the inhibition of angiogenesis, proliferation and metastasis and the activation of apoptosis. The improvement in before-treated group was more pronounced than that in after- and simultaneous-treated groups, indicating thatMEMC may act as a prophylactic agent more than being a therapeutic agent.

Evaluation of a xenogeneic vascular endothelial growth factor-2 vaccine in two preclinical metastatic tumor models in mice

In this study, a xenogeneic DNA vaccine encoding for human vascular endothelial growth factor receptor-2 (hVEGFR-2) was evaluated in two murine tumor models, the B16-F10 melanoma and the EO771 breast carcinoma model. The vaccine was administered by intradermal injection followed by electroporation. The immunogenicity and the biological efficacy of the vaccine were tested in (1) a prophylactic setting, (2) a therapeutic setting, and (3) a therapeutic setting combined with surgical removal of the primary tumor. The tumor growth, survival, and development of an immune response were followed. The cellular immune response was measured by a bioluminescence-based cytotoxicity assay with vascular endothelial growth factor-2 (VEGFR-2)-expressing target cells. Humoral immune responses were quantified by enzyme-linked immunosorbent assay (ELISA). Ex vivo bioluminescence imaging and immunohistological observation of organs were used to detect (micro)metastases. A cellular and humoral immune response was present in prophylactically and therapeutically vaccinated mice, in both tumor models. Nevertheless, survival in prophylactically vaccinated mice was only moderately increased, and no beneficial effect on survival in therapeutically vaccinated mice could be demonstrated. An influx of CD3+ cells and a slight decrease in VEGFR-2 were noticed in the tumors of vaccinated mice. Unexpectedly, the vaccine caused an increased quantity of early micrometastases in the liver. Lung metastases were not increased by the vaccine. These early liver micrometastases did however not grow into macroscopic metastases in either control or vaccinated mice when allowed to develop further after surgical removal of the primary tumor.

T-lymphocyte homing: an underappreciated yet critical hurdle for successful cancer immunotherapy

Advances in cancer immunotherapy have offered new hope for patients with metastatic disease. This unfolding success story has been exemplified by a growing arsenal of novel immunotherapeutics, including blocking antibodies targeting immune checkpoint pathways, cancer vaccines, and adoptive cell therapy (ACT). Nonetheless, clinical benefit remains highly variable and patient-specific, in part, because all immunotherapeutic regimens vitally hinge on the capacity of endogenous and/or adoptively transferred T-effector (T_eff) cells, including chimeric antigen receptor (CAR) T cells, to home efficiently into tumor target tissue. Thus, defects intrinsic to the multi-step T-cell homing cascade have become an obvious, though significantly underappreciated contributor to immunotherapy resistance. Conspicuous have been low intralesional frequencies of tumor-infiltrating T-lymphocytes (TILs) below clinically beneficial threshold levels, and peripheral rather than deep lesional TIL infiltration. Therefore, a T_eff cell 'homing deficit' may arguably represent a dominant factor responsible for ineffective immunotherapeutic outcomes, as tumors resistant to immune-targeted killing thrive in such permissive, immune-vacuous microenvironments. Fortunately, emerging data is shedding light into the diverse mechanisms of immune escape by which tumors restrict T_eff cell trafficking and lesional penetrance. In this review, we scrutinize evolving knowledge on the molecular determinants of T_eff cell navigation into tumors. By integrating recently described, though sporadic information of pivotal adhesive and chemokine homing signatures within the tumor microenvironment with better established paradigms of T-cell trafficking under homeostatic or infectious disease scenarios, we seek to refine currently incomplete models of T_eff cell entry into tumor tissue. We further summarize how cancers thwart homing to escape immune-mediated destruction and raise awareness of the potential impact of immune checkpoint blockers on T_eff cell homing. Finally, we speculate on innovative therapeutic opportunities for augmenting T_eff cell homing capabilities to improve immunotherapy-based tumor eradication in cancer patients, with special focus on malignant melanoma.

The prognostic value and pathobiological significance of Glasgow microenvironment score in gastric cancer

PURPOSE

To evaluate the prognostic value and pathobiological significance of Glasgow microenvironment score (GMS), a parameter based on tumor stroma percentage and inflammatory cell infiltration, in gastric cancer.

METHODS

A total of 225 cases of gastric cancer were histologically reviewed, and GMS was evaluated for each case. The association between GMS and patients' survival was investigated. Then the relationship between GMS and mismatch repair (MMR) status, Epstein-Barr virus (EBV) infection were determined using immunohistochemistry (IHC) and in situ hybridization, and the expression of PD1/PD-L1 was examined. Furthermore, the amount of cancer-associated fibroblasts (CAFs), the content and maturity of collagen components were detected using IHC, Picrosirius Red staining and second harmonic generation imaging.

RESULTS

GMS was significantly associated with clinical outcomes of gastric cancer, and multivariate analysis indicated that GMS was an independent factor (HR 1.725, P = 0.002). Low GMS was a manifestation of better prognosis and inflammatory tumor microenvironment, which was related to MMR deficiency (P = 0.042) and EBV infection (P = 0.032), and within this microenvironment, expression of PD-L1 in carcinoma cells (P = 0.030) or in inflammatory cells (P = 0.029) was significantly higher. In contrast, high GMS linked to a poorer survival and desmoplastic stroma, in which there existed markedly increased CAFs and collagen deposition.

CONCLUSION

GMS can serve as a useful prognostic factor for gastric cancer, and according to GMS, the tumor microenvironment in this cancer type may be partially classified as inflammatory or desmoplastic microenvironment that possesses different pathobiological features.

Immunotherapeutic Targeting of Tumor-Associated Blood Vessels

Pathological angiogenesis occurs during tumor progression and leads in the formation of an abnormal vasculature in the tumor microenvironment (TME). The tumor vasculature is disorganized, tortuous and leaky, resulting in high interstitial pressure and hypoxia in the TME, all of which are events that support tumor growth and survival. Given the sustaining role of the tumor vasculature, it has become an increasingly attractive target for the development of anti-cancer therapies. Antibodies, tyrosine kinase inhibitors and cancer vaccines that target pro-angiogenic factors, angiogenesis-associated receptors or tumor blood vessel-associated antigens continue to be developed and tested for therapeutic efficacy. Preferred anti-angiogenic protocols include those that "normalize" the tumor-associated vasculature which reduce hypoxia and improve tumor blood perfusion, resulting in tumor cell apoptosis, decreased immunosuppression, and enhanced effector immune cell infiltration/tumoricidal action within the TME.

Intracellular and intercellular signaling networks in cancer initiation, development and precision anti-cancer therapy: RAS acts as contextual signaling hub

Cancer initiation and development are increasingly perceived as systems-level phenomena, where intra- and inter-cellular signaling networks of the ecosystem of cancer and stromal cells offer efficient methodologies for outcome prediction and intervention design. Within this framework, RAS emerges as a 'contextual signaling hub', i.e. the final result of RAS activation or inhibition is determined by the signaling network context. Current therapies often 'train' cancer cells shifting them to a novel attractor, which has increased metastatic potential and drug resistance. The few therapy-surviving cancer cells are surrounded by massive cell death triggering a primordial adaptive and reparative general wound healing response. Overall, dynamic analysis of patient- and disease-stage specific intracellular and intercellular signaling networks may open new areas of anticancer therapy using multitarget drugs, drugs combinations, edgetic drugs, as well as help design 'gentler', differentiation and maintenance therapies.

The Action of Discoidin Domain Receptor 2 in Basal Tumor Cells and Stromal Cancer-Associated Fibroblasts Is Critical for Breast Cancer Metastasis

High levels of collagen deposition in human and mouse breast tumors are associated with poor outcome due to increased local invasion and distant metastases. Using a genetic approach, we show that, in mice, the action of the fibrillar collagen receptor discoidin domain receptor 2 (DDR2) in both tumor and tumor-stromal cells is critical for breast cancer metastasis yet does not affect primary tumor growth. In tumor cells, DDR2 in basal epithelial cells regulates the collective invasion of tumor organoids. In stromal cancer-associated fibroblasts (CAFs), DDR2 is critical for extracellular matrix production and the organization of collagen fibers. The action of DDR2 in CAFs also enhances tumor cell collective invasion through a pathway distinct from the tumor-cell-intrinsic function of DDR2. This work identifies DDR2 as a potential therapeutic target that controls breast cancer metastases through its action in both tumor cells and tumor-stromal cells at the primary tumor site.

Tumor-Associated Neutrophils Recruit Macrophages and T-Regulatory Cells to Promote Progression of Hepatocellular Carcinoma and Resistance to Sorafenib

BACKGROUND & AIMS

Neutrophils can either promote or inhibit tumor progression, depending on the tumor microenvironment, via release of cytokines. Neither the factors produced by tumor-associated neutrophils (TANs) nor their effects on tumor progression have been characterized. We investigated the roles of TANs in progression of hepatocellular carcinoma (HCC) using cell lines and immune cells isolated from patients.

METHODS

We performed studies with HepG2, PLC/PRF/5, MHCC97H, and HCCLM3 human and Hepa1-6 and H22 mouse HCC cell lines; expression of chemokines and cytokines were knocked down with small hairpin RNAs. Cells were analyzed in chemotaxis assays and as growth as tumors in mice. HCC tissues and peripheral blood were collected from 20 patients undergoing curative resection or 20 healthy individuals (controls) in 2012 at Zhongshan Hospital in China. TANs and peripheral blood neutrophils (PBNs) were isolated and exposed to conditioned media from HCC cell lines; reverse-transcription polymerase chain reaction was used to quantify the expression of cytokines and chemokines. We collected neutrophils from another 60 patients undergoing curative resection for HCC in 2012 to measure the production of C-C motif chemokine ligand 2(CCL2) and CCL17. Patients were followed up until March 15, 2014. For immunohistochemical analyses, we collected HCC tissues and paired, adjacent, nontumor cirrhotic liver tissues from 832 HCC patients undergoing curative resection from 2006 through 2008. All patients were followed up until March 15, 2013. To study the effects of sorafenib, we collected clinical and pathology data from 46 patients who underwent curative resection in 2010.

RESULTS

CCL2 and CCL17 were the cytokines most highly expressed by TANs and HCC cell-activated PBNs. Levels of CCL2 and CCL17 messenger RNAs and proteins were significantly higher in TANs than in PBNs, and increased in patients with HCC recurrence. CCL2 and CCL17 messenger RNA and proteins also increased when PBNs were exposed to conditioned media from HCC cell lines. Immunohistochemical analysis of a tissue microarray showed that CCL2+ and CCL17+ cells, which also expressed the neutrophil marker CD66b, were distributed throughout the HCC stroma, but not in tumor cells or the adjacent nontumor liver cells. The number of CCL2+ or CCL17+ TANs correlated with tumor size, microvascular invasion, tumor encapsulation, tumor differentiation, and stage. Patients whose tumors had lower levels of CCL2+ or CCL17+ cells had longer survival times than those with higher numbers of these cells. TAN-conditioned media, as well as recombinant CCL2 and CCL17, increased the migratory activity of the macrophages and T-regulatory (Treg) cells from patients or mice with HCC to a greater extent that PBN-conditioned media. Neutralizing antibodies against CCL2 and CCL17, or their receptors C-C chemokine receptor 2 and C-C chemokine receptor 4, reduced the migratory activities of macrophage and Treg cells. HCC cell lines injected into mice formed larger tumors when they were co-injected with TANs and formed more pulmonary metastases; these tumors were infiltrated by Ly6G+ cells, F4/80+ macrophages, and Foxp3+ Treg cells. In a phosphokinase array of human PBNs, levels of phosphorylated AKT and P38 increased after exposure to conditioned media from all 4 HCC cell types. Pharmacologic inhibitors of AKT and P38 inhibited secretion of CCL2 and CCL17 by these PBNs. In tumor-bearing mice, sorafenib increased the numbers of TANs and levels of CCL2 and CCL17 in tumors. HCC tissues from patients who received sorafenib before surgery contained more TANs than tissues from patients who did not receive sorafenib. In knockdown cells, HCC cell-derived CXCL5 was the strongest effector of neutrophil migration under hypoxic conditions. In mice, the combination of sorafenib and TAN depletion inhibited tumor growth and neovascularization to a greater extent than sorafenib alone.

CONCLUSIONS

TANs recruit macrophages and Treg cells to HCCs to promote their growth, progression, and resistance to sorafenib.

A Bayesian Nonparametric Approach for Functional Data Classification with Application to Hepatic Tissue Characterization

Computed tomography perfusion (CTp) is an emerging functional imaging technology that provides a quantitative assessment of the passage of fluid through blood vessels. Tissue perfusion plays a critical role in oncology due to the proliferation of networks of new blood vessels typical of cancer angiogenesis, which triggers modifications to the vasculature of the surrounding host tissue. In this article, we consider a Bayesian semiparametric model for the analysis of functional data. This method is applied to a study of four interdependent hepatic perfusion CT characteristics that were acquired under the administration of contrast using a sequence of repeated scans over a period of 590 seconds. More specifically, our modeling framework facilitates borrowing of information across patients and tissues. Additionally, the approach enables flexible estimation of temporal correlation structures exhibited by mappings of the correlated perfusion biomarkers and thus accounts for the heteroskedasticity typically observed in those measurements, by incorporating change-points in the covariance estimation. This method is applied to measurements obtained from regions of liver surrounding malignant and benign tissues, for each perfusion biomarker. We demonstrate how to cluster the liver regions on the basis of their CTp profiles, which can be used in a prediction context to classify regions of interest provided by future patients, and thereby assist in discriminating malignant from healthy tissue regions in diagnostic settings.

Chrysin-organogermanium (IV) complex induced Colo205 cell apoptosis-associated mitochondrial function and anti-angiogenesis

Colorectal cancer, a kind of malignant cancer, has more than 1 million new patients and results in 0.5 million deaths every year globally based on the estimation of Globocan in 2008. One of the most important issues against colon cancer is tumor metastasis. Anti-angiogenesis, a form of targeted therapy uses drugs or other substances to prevent the new blood vessel formation, which is critical for tumor metastasis. In our previous studies, we have demonstrated a simple method to synthesize Chry-Ge complex through the reaction between chrysin and triphenylgermanium bromide. In this work, we investigated the mechanism of Chry-Ge induced Colo205 cell apoptosis. We found that Chry-Ge could induce apoptosis in Colo205 cells in mitochondrial-dependent pathway, cause the reorganization of cytoskeleton and induce the damage of nucleus in Colo205 cells. Besides, Chry-Ge was also found to induce membrane ultrastructural changes in Colo205 cells by AFM. Further, we found that Chry-Ge can inhibit tube formation of human umbilical vascular endothelial cell in vitro. Chry-Ge was also tested in vivo in the chicken chorioallantoic membrane (CAM) assay and found to inhibit bFGF-treated CAMs development. These results suggested that Chry-Ge could induce Colo205 cell apoptosis by mitochondrial pathway and anti-angiogenesis, highlighting the use of organic germanium agents for the treatment of colorectal cancer.

Design, synthesis and biological evaluation of imidazopyridine/imidazopyrimidine-benzimidazole conjugates as potential anticancer agents

A series of imidazopyridine/imidazopyrimidine-benzimidazole conjugates (11a–t) were synthesized and evaluated for their antiproliferative activity.

Evaluation of a tumor microenvironment-based prognostic score in primary operable colorectal cancer

PURPOSE

The tumor microenvironment is recognized as an important determinant of progression and outcome in colorectal cancer. The aim of the present study was to evaluate a novel tumor microenvironment-based prognostic score, based on histopathologic assessment of the tumor inflammatory cell infiltrate and tumor stroma, in patients with primary operable colorectal cancer.

EXPERIMENTAL DESIGN

Using routine pathologic sections, the tumor inflammatory cell infiltrate and stroma were assessed using Klintrup-Mäkinen (KM) grade and tumor stroma percentage (TSP), respectively, in 307 patients who had undergone elective resection for stage I-III colorectal cancer. The clinical utility of a cumulative score based on these characteristics was examined.

RESULTS

On univariate analysis, both weak KM grade and high TSP were associated with reduced survival (HR, 2.42; P = 0.001 and HR, 2.05; P = 0.001, respectively). A cumulative score based on these characteristics, the Glasgow Microenvironment Score (GMS), was associated with survival (HR, 1.93; 95% confidence interval, 1.36-2.73; P < 0.001), independent of TNM stage and venous invasion (both P < 0.05). GMS stratified patients in to three prognostic groups: strong KM (GMS = 0), weak KM/low TSP (GMS = 1), and weak KM/high TSP (GMS = 2), with 5-year survival of 89%, 75%, and 51%, respectively (P < 0.001). Furthermore, GMS in combination with node involvement, venous invasion, and mismatch repair status further stratified 5-year survival (92% to 37%, 93% to 27%, and 100% to 37%, respectively).

CONCLUSIONS

The present study further confirms the clinical utility of assessment of the tumor microenvironment in colorectal cancer and introduces a simple, routinely available prognostic score for the risk stratification of patients with primary operable colorectal cancer.

ASC, a bioactive steroidal saponin from Ophitopogin japonicas, inhibits angiogenesis through interruption of Src tyrosine kinase-dependent matrix metalloproteinase pathway

As angiogenesis is an important target for antitumour drugs, the agents that inhibit angiogenesis may help reduce the use of chemotherapy by blocking tumour blood supply. In this study, we investigated a potent angiogenesis inhibitor, ASC, a steroidal saponin compound, which has been purified from Ophitopogin japonicus (L.f) Ker.-Gawl. Our observations showed that ASC significantly suppressed human umbilical vein endothelial cell (HUVECs) growth both in vitro and in vivo. This may be resulted from the G2/M cell cycle arrest effects of ASC. Moreover, ASC inhibited HUVECs invasion and tube formation processes, which were associated with endothelial cells remodelling. A mechanism study indicated that ASC down-regulated the expression of Src tyrosine kinase, further leading to the blockage of Akt-dependent matrix metalloproteinases (mainly for MMP-9) signalling pathway, which was functionally associated with angiogenic blood vessels. Finally, ASC significantly inhibited angiogenesis and MMPs/VEGF expression in the subcutaneously injected matrigel in C57/BL mice. These findings suggest that ASC might be a potential drug candidate in anti-angiogenesis and anticancer therapies.

Surface density of vascular endothelial growth factor modulates endothelial proliferation and differentiation

Therapeutic strategies aim to regulate vasculature either by encouraging vessel growth for tissue engineering or inhibiting vascularization around a tumor. Vascular endothelial growth factor (VEGF) is essential to these processes, and there are several strategies that manipulate VEGF signaling. Here we develop a method to control the surface density of VEGF, which is covalently attached to tissue culture polystyrene (TCPS), and explore cellular responses to surfaces with varying VEGF densities. We show that the crosslinker reduces but does not eliminate the biological activity of soluble VEGF as measured by endothelial proliferation. However, endothelial cells cultured on surfaces of covalently bound VEGF did not proliferate in response to surface cues. Interestingly, compared to cells incubated with soluble VEGF (10 ng/ml) and cultured on TCPS, lower cell proliferation was observed when endothelial cells were cultured on high VEGF surface densities (5.9 ng/cm(2)), whereas higher cell proliferation occurred when cells were cultured on low surface densities (0.04 ng/cm(2)). High density surfaces (5.9 ng/cm(2)) also acted in synergy with an inhibitor of VEGF receptors to further suppress endothelial cell proliferation. We also examined the effect of VEGF surfaces on endothelial differentiation of mesenchymal stem cells. No effect was observed when cells were cultured on VEGF surfaces; however, the VEGF surfaces acted in synergy with an inhibitor of VEGF receptors to decrease the ability of differentiated cells to form vascular networks. Together, these results suggest that surface density of bound VEGF can be used to modulate cell behavior and inhibit an angiogenic response.

Lectin-like oxidized LDL receptor-1 is an enhancer of tumor angiogenesis in human prostate cancer cells

Altered expression and function of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) has been associated with several diseases such as endothelial dysfunction, atherosclerosis and obesity. In these pathologies, oxLDL/LOX-1 activates signaling pathways that promote cell proliferation, cell motility and angiogenesis. Recent studies have indicated that olr1 mRNA is over-expressed in stage III and IV of human prostatic adenocarcinomas. However, the function of LOX-1 in prostate cancer angiogenesis remains to be determined. Our aim was to analyze the contribution of oxLDL and LOX-1 to tumor angiogenesis using C4-2 prostate cancer cells. We analyzed the expression of pro-angiogenic molecules and angiogenesis on prostate cancer tumor xenografts, using prostate cancer cell models with overexpression or knockdown of LOX-1 receptor. Our results demonstrate that the activation of LOX-1 using oxLDL increases cell proliferation, and the expression of the pro-angiogenic molecules VEGF, MMP-2, and MMP-9 in a dose-dependent manner. Noticeably, these effects were prevented in the C4-2 prostate cancer model when LOX-1 expression was knocked down. The angiogenic effect of LOX-1 activated with oxLDL was further demonstrated using the aortic ring assay and the xenograft model of tumor growth on chorioallantoic membrane of chicken embryos. Consequently, we propose that LOX-1 activation by oxLDL is an important event that enhances tumor angiogenesis in human prostate cancer cells.

Tumour microenvironments induce expression of urokinase plasminogen activator receptor (uPAR) and concomitant activation of gelatinolytic enzymes

Background

The urokinase plasminogen activator receptor (uPAR) is associated with poor prognosis in oral squamous cell carcinoma (OSCC), and increased expression of uPAR is often found at the invasive tumour front. The aim of the current study was to elucidate the role of uPAR in invasion and metastasis of OSCC, and the effects of various tumour microenvironments in these processes. Furthermore, we wanted to study whether the cells’ expression level of uPAR affected the activity of gelatinolytic enzymes.

Methods

The Plaur gene was both overexpressed and knocked-down in the murine OSCC cell line AT84. Tongue and skin tumours were established in syngeneic mice, and cells were also studied in an ex vivo leiomyoma invasion model. Soluble factors derived from leiomyoma tissue, as well as purified extracellular matrix (ECM) proteins, were assessed for their ability to affect uPAR expression, glycosylation and cleavage. Activity of gelatinolytic enzymes in the tissues were assessed by in situ zymography.

Results

We found that increased levels of uPAR did not induce tumour invasion or metastasis. However, cells expressing low endogenous levels of uPAR in vitro up-regulated uPAR expression both in tongue, skin and leiomyoma tissue. Various ECM proteins had no effect on uPAR expression, while soluble factors originating from the leiomyoma tissue increased both the expression and glycosylation of uPAR, and possibly also affected the proteolytic processing of uPAR. Tumours with high levels of uPAR, as well as cells invading leiomyoma tissue with up-regulated uPAR expression, all displayed enhanced activity of gelatinolytic enzymes.

Conclusions

Although high levels of uPAR are not sufficient to induce invasion and metastasis, the activity of gelatinolytic enzymes was increased. Furthermore, several tumour microenvironments have the capacity to induce up-regulation of uPAR expression, and soluble factors in the tumour microenvironment may have an important role in the regulation of posttranslational modification of uPAR.

AmotL2 disrupts apical-basal cell polarity and promotes tumour invasion

The establishment and maintenance of apical-basal cell polarity is essential for the functionality of glandular epithelia. Cell polarity is often lost in advanced tumours correlating with acquisition of invasive and malignant properties. Despite extensive knowledge regarding the formation and maintenance of polarity, the mechanisms that deregulate polarity in metastasizing cells remain to be fully characterized. Here we show that AmotL2 expression correlates with loss of tissue architecture in tumours from human breast and colon cancer patients. We further show that hypoxic stress results in activation of c-Fos-dependent expression of AmotL2 leading to loss of polarity. c-Fos/hypoxia-induced p60 AmotL2 interacts with the Crb3 and Par3 polarity complexes retaining them in large vesicles and preventing them from reaching the apical membrane. The resulting loss of polarity potentiates the response to invasive cues in vitro and in vivo in mice. These data provide a molecular mechanism how hypoxic stress deregulates cell polarity during tumour progression.

3D cell culture systems modeling tumor growth determinants in cancer target discovery

Phenotypic heterogeneity of cancer cells, cell biological context, heterotypic crosstalk and the microenvironment are key determinants of the multistep process of tumor development. They sign responsible, to a significant extent, for the limited response and resistance of cancer cells to molecular-targeted therapies. Better functional knowledge of the complex intra- and intercellular signaling circuits underlying communication between the different cell types populating a tumor tissue and of the systemic and local factors that shape the tumor microenvironment is therefore imperative. Sophisticated 3D multicellular tumor spheroid (MCTS) systems provide an emerging tool to model the phenotypic and cellular heterogeneity as well as microenvironmental aspects of in vivo tumor growth. In this review we discuss the cellular, chemical and physical factors contributing to zonation and cellular crosstalk within tumor masses. On this basis, we further describe 3D cell culture technologies for growth of MCTS as advanced tools for exploring molecular tumor growth determinants and facilitating drug discovery efforts. We conclude with a synopsis on technological aspects for on-line analysis and post-processing of 3D MCTS models.

The relationship between tumour stroma percentage, the tumour microenvironment and survival in patients with primary operable colorectal cancer

BACKGROUND

Tumour stroma percentage (TSP) has previously been reported to predict survival in patients with colorectal cancer (CRC); however, whether this is independent of other aspects of the tumour microenvironment is unknown. In the present study, the relationship between TSP, the tumour microenvironment and survival was examined in patients undergoing elective, curative CRC resection.

PATIENTS AND METHODS

Patients undergoing resection at a single centre (1997-2008) were identified from a prospective database. TSP was measured at the invasive margin and its association with cancer-specific survival (CSS) and clinicopathological characteristics examined.

RESULTS

Three hundred and thirty-one patients were included in the analysis. TSP was associated with CSS in patients with stage I-III disease [hazard ratio (HR) 1.84, 95% confidence interval (CI) 1.17-2.92, P = 0.009], independent of age, systemic inflammation, N stage, venous invasion and Klintrup-Mäkinen score. Furthermore, TSP was associated with reduced CSS in patients with node-negative disease (HR 2.14, 95% CI 1.01-4.54, P = 0.048) and those who received adjuvant chemotherapy (HR 2.83, 95% CI 1.23-6.53, P = 0.015), independent of venous invasion and host inflammatory responses. TSP was associated with several adverse pathological characteristics, including advanced T and N stage. Furthermore, TSP was associated with an infiltrative invasive margin and inversely associated with necrosis.

CONCLUSIONS

The TSP was a significant predictor of survival in patients undergoing elective, curative CRC resection, independent of adverse pathological characteristics and host inflammatory responses. In addition, TSP was strongly associated with local tumour growth and invasion.

Roadblocks to translational advances on metastasis research

Promising advances in cancer therapy stemming from an increasing understanding of the molecular and genetic underpinnings of the tumorigenic process have been fueled by a strong, determined scientific community, influential patient advocacy groups and committed funding bodies. Despite these efforts, the development of effective drugs to prevent systemic dissemination of cancer cells or to eliminate overt metastasis in secondary organs remains a challenge to both researchers and physicians. In an attempt to tackle the most relevant and timely translational issues, a meeting held in 2012 as a result of a successful partnership between the Volkswagen Foundation and Nature Medicine brought together a group of metastasis research experts to identify the most important hurdles and help create a framework for potential clinical and translational strategies.

Expression of angiogenic factors in hepatocarcinogenesis: Identification by antibody arrays

Angiogenesis plays a pivotal role in the progression and metastasis of hepatocellular carcinoma (HCC). However, the expression of a wide range of angiogenic factors remains obscure in HCC. The purpose of the present study was to determine the expression of various angiogenic factors related to hepatocarcinogenesis. We examined the expression of 19 angiogenic factors using antibody arrays in human tissues of various liver diseases, including HCC. We also studied the expression of 19 angiogenic factors in the human HCC cell lines PLC/PRF/5, Hep 3B, HuH7, HLE, HLF and Li-7 and the normal hepatocyte cell line ACBRI3716. In human tissues, although the expression of acidic fibroblast growth factor (aFGF) was found to increase from normal liver to chronic hepatitis, its expression remained unchanged in the transition from chronic hepatitis to HCC. Vascular endothelial growth factor (VEGF) was elevated in liver cirrhosis, but the amounts remained unchanged in the transition from liver cirrhosis to HCC. In contrast, either interleukin-8 (IL-8) or basic fibroblast growth factor (bFGF) was upregulated in HCC. In the HCC cell lines PLC/PRF/5, Hep 3B and HuH-7, the expression of IL-8 was elevated. Although IL-8 was not elevated, bFGF was upregulated in the other HCC cell lines HLE, HLF and Li-7. Thus, either IL-8 or bFGF was upregulated in HCC cell lines and in HCC tissue samples. These data suggest that the upregulation of either IL-8 or bFGF is closely related to the transition from liver cirrhosis into HCC. Therefore, the analysis of the expression of these cytokines using protein arrays may identify novel therapies for individual patients with HCC.

Tumor cell-mediated neovascularization and lymphangiogenesis contrive tumor progression and cancer metastasis

Robust neovascularization and lymphangiogenesis have been found in a variety of aggressive and metastatic tumors. Endothelial sprouting angiogenesis is generally considered to be the major mechanism by which new vasculature forms in tumors. However, increasing evidence shows that tumor vasculature is not solely composed of endothelial cells (ECs). Some tumor cells acquire processes similar to embryonic vasculogenesis and produce new vasculature through vasculogenic mimicry, trans-differentiation of tumor cells into tumor ECs, and tumor cell-EC vascular co-option. In addition, tumor cells secrete various vasculogenic factors that induce sprouting angiogenesis and lymphangiogenesis. Vasculogenic tumor cells actively participate in the formation of vascular cancer stem cell niche and a premetastatic niche. Therefore, tumor cell-mediated neovascularization and lymphangiogenesis are closely associated with tumor progression, cancer metastasis, and poor prognosis. Vasculogenic tumor cells have emerged as key players in tumor neovascularization and lymphangiogenesis and play pivotal roles in tumor progression and cancer metastasis. However, the mechanisms underlying tumor cell-mediated vascularity as they relate to tumor progression and cancer metastasis remain unclear. Increasing data have shown that various intrinsic and extrinsic factors activate oncogenes and vasculogenic genes, enhance vasculogenic signaling pathways, and trigger tumor neovascularization and lymphangiogenesis. Collectively, tumor cells are the instigators of neovascularization. Therefore, targeting vasculogenic tumor cells, genes, and signaling pathways will open new avenues for anti-tumor vasculogenic and metastatic drug discovery. Dual targeting of endothelial sprouting angiogenesis and tumor cell-mediated neovascularization and lymphangiogenesis may overcome current clinical problems with anti-angiogenic therapy, resulting in significantly improved anti-angiogenesis and anti-cancer therapies.