Angiogenesis and the tumor microenvironment: vascular endothelial growth factor and beyond

Dissecting the multifaceted roles of autophagy in cancer initiation, growth, and metastasis: from molecular mechanisms to therapeutic applications

Autophagy is a cytoplasmic defense mechanism that cells use to break and reprocess their intracellular components. This utilization of autophagy is regarded as a savior in nutrient-deficient and other stressful conditions. Hence, autophagy keeps contact with and responds to miscellaneous cellular tensions and diverse pathways of signal transductions, such as growth signaling and cellular death. Importantly, autophagy is regarded as an effective tumor suppressor because regular autophagic breakdown is essential for cellular maintenance and minimizing cellular damage. However, paradoxically, autophagy has also been observed to promote the events of malignancies. This review discussed the dual role of autophagy in cancer, emphasizing its influence on tumor survival and progression. Possessing such a dual contribution to the malignant establishment, the prevention of autophagy can potentially advocate for the advancement of malignant transformation. In contrast, for the context of the instituted tumor, the agents of preventing autophagy potently inhibit the advancement of the tumor. Key regulators, including calpain 1, mTORC1, and AMPK, modulate autophagy in response to nutritional conditions and stress. Oncogenic mutations like RAS and B-RAF underscore autophagy's pivotal role in cancer development. The review also delves into autophagy's context-dependent roles in tumorigenesis, metastasis, and the tumor microenvironment (TME). It also discusses the therapeutic effectiveness of autophagy for several cancers. The recent implication of autophagy in the control of both innate and antibody-mediated immune systems made it a center of attention to evaluating its role concerning tumor antigens and treatments of cancer.

Prognostic correlation between specialized capillary endothelial cells and lung adenocarcinoma

Background

In-depth analysis of the functional changes occurring in endothelial cells (ECs) involved in capillary formation can help to elucidate the mechanism of tumour vascular growth.

Methods

Appropriate datasets were retrieved from the GEO database to obtain single-cell data on LUAD samples and adjacent normal tissue samples. ECs were selected by an automatic annotation program in R and further subdivided based on reported EC marker genes. Functional changes in different types of capillary ECs were then visualized, and the concrete expression was classified by genetic data in the TCGA. Finally, a prognostic model was constructed to predict immunoinfiltration status, survival and drug therapy effects.

Results

The LUAD data contained in the GSE183219 dataset were suitable for our analysis. After dimensionality reduction analysis and cell annotation, EC general capillary and EC aerocyte subsets as capillary specialized phenotypes showed a series of functional changes in tumour samples, with a total of 108 genes found to undergo functional changes. Use of CellPhoneDB revealed a close interaction of activity between ECs. After integration of TCGA, GSE68465 and GSE11969 datasets, the genes obtained were analysed by cluster analysis and risk model construction, identifying 8 genes. Drug sensitivity, immune cell and molecular differences can be accurately predicted.

Conclusions

EC general capillary and EC aerocyte subsets are recognized capillary ECs in the tumour microenvironment, and the functional changes between them are relevant to the prognosis and treatment of LUAD patients and have the potential to be used in target therapy.

Measuring the composition of the tumor microenvironment with transcriptome analysis: past, present and future

Interactions between tumor cells and immune cells in the tumor microenvironment (TME) play a vital role the mechanisms of immune evasion, by which cancer cells escape immune elimination. Thus, the characterization and quantification of different components in the TME is a hot topic in molecular biology and drug discovery. Since the development of transcriptome sequencing in bulk tissue, single cells and spatial dimensions, there are increasing methods emerging to deconvolute and subtype the TME. This review discusses and compares such computational strategies and downstream subtyping analyses. Integrative analyses of the transcriptome with other data, such as epigenetics and T-cell receptor sequencing, are needed to obtain comprehensive knowledge of the dynamic TME.

Dihydroartemisinin inhibits angiogenesis in breast cancer via regulating VEGF and MMP-2/-9

BACKGROUND

Dihydroartemisinin (DHA) is an artemisinin derivative known for its antimalarial properties. It has also shown potential as an anti-tumor and anti-angiogenic agent. However, its specific role in inhibiting angiogenesis in breast cancer is not well understood.

OBJECTIVES

We aimed to investigate the anti-angiogenesis effect of DHA on breast cancer and explore its potential as a therapeutic drug. Our objectives were to assess the impact of DHA on neovascularization induced by MDA-MB-231 cells, evaluate its effects on vessel sprout and tube-formation in vascular endothelial cells, and analyze the expression of key angiogenesis-related proteins.

METHODS

Using a chicken chorioallantoic membrane (CAM) model, we cultured MDA-MB-231 cells and treated them with DHA. We assessed neovascularization and cultured vascular endothelial cells with DHA-treated cell media to evaluate vessel sprout and tube-formation. Protein expression levels of VEGF, MMP-2, and MMP-9 were analyzed using Western blotting.

RESULTS

DHA significantly attenuated neovascularization induced by MDA-MB-231 cells. It also suppressed vessel sprout and tube-formation of HUVEC cells when exposed to DHA-treated cell media. Furthermore, DHA downregulated the expression of VEGF, MMP-2, and MMP-9 proteins. Mechanistically, DHA inhibited the phosphorylation of PI3K, AKT, ERK, and NF-κB proteins in tumor cells.

CONCLUSIONS

Our study provides evidence of the inhibitory effect of DHA on breast cancer angiogenesis. These findings support the potential of DHA as an anti-breast cancer drug and warrant further investigation for its therapeutic applications.

Targeting anticancer immunity in oral cancer: Drugs, products, and nanoparticles

Oral cavity carcinomas are the most frequent malignancies among head and neck malignancies. Oral tumors include not only oral cancer cells with different potency and stemness but also consist of diverse cells, containing anticancer immune cells, stromal and also immunosuppressive cells that influence the immune system reactions. The infiltrated T and natural killer (NK) cells are the substantial tumor-suppressive immune compartments in the tumor. The infiltration of these cells has substantial impacts on the response of tumors to immunotherapy, chemotherapy, and radiotherapy. Nevertheless, cancer cells, stromal cells, and some other compartments like regulatory T cells (Tregs), macrophages, and myeloid-derived suppressor cells (MDSCs) can repress the immune responses against malignant cells. Boosting anticancer immunity by inducing the immune system or repressing the tumor-promoting cells is one of the intriguing approaches for the eradication of malignant cells such as oral cancers. This review aims to concentrate on the secretions and interactions in the oral tumor immune microenvironment. We review targeting tumor stroma, immune system and immunosuppressive interactions in oral tumors. This review will also focus on therapeutic targets and therapeutic agents such as nanoparticles and products with anti-tumor potency that can boost anticancer immunity in oral tumors. We also explain possible future perspectives including delivery of various cells, natural products and drugs by nanoparticles for boosting anticancer immunity in oral tumors.

Ellagic Acid and Cancer Hallmarks: Insights from Experimental Evidence

Cancer is a complex and multifaceted disease with a high global incidence and mortality rate. Although cancer therapy has evolved significantly over the years, numerous challenges persist on the path to effectively combating this multifaceted disease. Natural compounds derived from plants, fungi, or marine organisms have garnered considerable attention as potential therapeutic agents in the field of cancer research. Ellagic acid (EA), a natural polyphenolic compound found in various fruits and nuts, has emerged as a potential cancer prevention and treatment agent. This review summarizes the experimental evidence supporting the role of EA in targeting key hallmarks of cancer, including proliferation, angiogenesis, apoptosis evasion, immune evasion, inflammation, genomic instability, and more. We discuss the molecular mechanisms by which EA modulates signaling pathways and molecular targets involved in these cancer hallmarks, based on in vitro and in vivo studies. The multifaceted actions of EA make it a promising candidate for cancer prevention and therapy. Understanding its impact on cancer biology can pave the way for developing novel strategies to combat this complex disease.

Anaplerotic nutrient stress drives synergy of angiogenesis inhibitors with therapeutics targeting tumor metabolism

Tumor angiogenesis is a cancer hallmark, and its therapeutic inhibition has provided meaningful, albeit limited, clinical benefit. While anti-angiogenesis inhibitors deprive the tumor of oxygen and essential nutrients, cancer cells activate metabolic adaptations to diminish therapeutic response. Despite these adaptations, angiogenesis inhibition incurs extensive metabolic stress, prompting us to consider such metabolic stress as an induced vulnerability to therapies targeting cancer metabolism. Metabolomic profiling of angiogenesis-inhibited intracranial xenografts showed universal decrease in tricarboxylic acid cycle intermediates, corroborating a state of anaplerotic nutrient deficit or stress. Accordingly, we show strong synergy between angiogenesis inhibitors (Avastin, Tivozanib) and inhibitors of glycolysis or oxidative phosphorylation through exacerbation of anaplerotic nutrient stress in intracranial orthotopic xenografted gliomas. Our findings were recapitulated in GBM xenografts that do not have genetically predisposed metabolic vulnerabilities at baseline. Thus, our findings cement the central importance of the tricarboxylic acid cycle as the nexus of metabolic vulnerabilities and suggest clinical path hypothesis combining angiogenesis inhibitors with pharmacological cancer interventions targeting tumor metabolism for GBM tumors.

The Landscape of Small Leucine-Rich Proteoglycan Impact on Cancer Pathogenesis with a Focus on Biglycan and Lumican

Cancer development is a multifactorial procedure that involves changes in the cell microenvironment and specific modulations in cell functions. A tumor microenvironment contains tumor cells, non-malignant cells, blood vessels, cells of the immune system, stromal cells, and the extracellular matrix (ECM). The small leucine-rich proteoglycans (SLRPs) are a family of nineteen proteoglycans, which are ubiquitously expressed among mammalian tissues and especially abundant in the ECM. SLRPs are divided into five canonical classes (classes I-III, containing fourteen members) and non-canonical classes (classes IV-V, including five members) based on their amino-acid structural sequence, chromosomal organization, and functional properties. Variations in both the protein core structure and glycosylation status lead to SLRP-specific interactions with cell membrane receptors, cytokines, growth factors, and structural ECM molecules. SLRPs have been implicated in the regulation of cancer growth, motility, and invasion, as well as in cancer-associated inflammation and autophagy, highlighting their crucial role in the processes of carcinogenesis. Except for the class I SLRP decorin, to which an anti-tumorigenic role has been attributed, other SLPRs' roles have not been fully clarified. This review will focus on the functions of the class I and II SLRP members biglycan and lumican, which are correlated to various aspects of cancer development.

CXCL10 is a prognostic marker for pancreatic adenocarcinoma and tumor microenvironment remodeling

BACKGROUND

The tumor microenvironment (TME) plays a crucial role in the progression of pancreatic adenocarcinoma (PAAD). However, challenges remain regarding the role played by TME associated genes in the prognosis of PAAD.

METHODS

The scores of tumor infiltrating immune cells (TICs), the immune and stroma scores of 182 PAAD patients in the Cancer Genome Atlas (TCGA) database were determined using CIBERSORT and ESTIMATE calculations. The final genes were identified by protein-protein interaction (PPI) networks and univariate Cox regression of differentially expressed genes. Finally, the correlation between gene expression and TCGA and clinical characteristics of patients in local hospital database was discussed. Gene set enrichment analysis (GSEA), the association between CXCL10 expression and TICs components were conducted.

RESULTS

In TCGA database and local hospital data, CXCL10 expression was correlated with the survival rate and TNM classification of patients with PAAD. Immune-related activities were enriched in the CXCL10 high expression group, while metabolic pathways were enriched in the CXCL10 low expression group. The expression of CXCL10 correlated with the proportion of TICs. CXCL10 expression was correlated with the proportion of TICs.

CONCLUSION

CXCL10 is a potential prognostic marker for PAAD and provide additional insights into the treatment of PAAD based on TME transformation. However, more independent experimentation with the CXCL10 is need.

Changes in Expression of Tumor Suppressor Gene RKIP Impact How Cancers Interact with Their Complex Environment

Tumor microenvironment (TME) is the immediate environment where cancer cells reside in a tumor. It is composed of multiple cell types and extracellular matrix. Microenvironments can be restrictive or conducive to the progression of cancer cells. Initially, microenvironments are suppressive in nature. Stepwise accumulation of mutations in oncogenes and tumor suppressor genes enables cancer cells to acquire the ability to reshape the microenvironment to advance their growth and metastasis. Among the many genetic events, the loss-of-function mutations in tumor suppressor genes play a pivotal role. In this review, we will discuss the changes in TME and the ramifications on metastasis upon altered expression of tumor metastasis suppressor gene RKIP in breast cancer cells.

Synthesis and Biological Evaluation of Potential Oncoimmunomodulator Agents

Fourteen triazole-scaffold derivatives were synthetized and biologically evaluated as potential oncoimmunomodultator agents by targeting both PD-L1 and c-Myc. First, the antiproliferative activity of these molecules on the monocultures of several tumor cell lines (HT-29, A-549, and MCF-7) and on the non-tumor cell line HEK-293 was studied. Then, the effects on the mentioned biological targets were also evaluated. Finally, the effect on cancer cell viability when the molecules were co-cultured with immune cells (Jurkat T cells or THP-1) was also determined. Compounds bearing a bromoophenyl group were selected because of their excellent results, and their effect on IL-6 secretion was also studied. In conclusion, we found compounds that are capable of downregulating c-Myc, as well as influencing and altering the distribution of PD-L1 in tumor cells; the compounds are thus capable of influencing the behavior of defensive cells towards cancer cells. p-Bromophenyltriazol 3 is the most active of these as a PD-L1 and c-Myc downregulator and as a potential immunomodulator agent. Moreover, it exhibits an interesting action on inflammation-related cytokine IL-6.

Anlotinib plus Epirubicin Followed by Anlotinib Maintenance as First-line Treatment for Advanced Soft-tissue Sarcoma: An Open-label, Single-arm, Phase II Trial

PURPOSE

The treatment outcome for locally advanced or metastatic soft-tissue sarcoma (STS) remains unsatisfactory. Anlotinib had demonstrated impressive activity in the subsequent-line treatment of STS. This study investigated the combination of anlotinib and epirubicin followed by anlotinib maintenance as first-line treatment for patients with advanced STS.

PATIENTS AND METHODS

This prospective, open-label, single-arm, phase II trial was conducted in Zhongshan Hospital, Fudan University. Eligible patients were ages 18 years or older and had previously untreated, pathologically confirmed, unresectable locally advanced or metastatic STS. All patients received up to six cycles of anlotinib plus epirubicin followed by anlotinib maintenance until disease progression, unacceptable toxicity, or death. The primary endpoint was the progression-free survival (PFS) rate at 6 months. The study was registered on chictr.org (identifier ChiCTR1900024928).

RESULTS

From June 2019 to August 2020, 30 patients were enrolled. By December 2021, the median PFS was 11.5 months [95% confidence interval (CI): 8.6-14.4 months], while the median overall survival was not reached (95% CI: NE-NE). The objective response rate was 13.33% and the disease control rate was 80.0%. The most common adverse events (AE) included anemia (43.3%), nausea/vomiting (40.0%), fatigue (36.7%), leukopenia (30.0%), and proteinuria (10.0%), which were mainly of grade 1 or 2. The most frequent grade 3 or 4 AEs were anemia (10.0%), febrile neutropenia (33.3%), hypothyroidism (3.3%), and leukopenia (3.3%). No treatment-related death occurred.

CONCLUSIONS

The combination of anlotinib and epirubicin followed by anlotinib maintenance demonstrated promising efficacy with a favorable safety profile.

Tannic Acid Exhibits Antiangiogenesis Activity in Nonsmall-Cell Lung Cancer Cells

Nonsmall-cell lung cancer (NSCLC) is the most common type of lung cancer, with a dismal prognosis. NSCLC is a highly vascularized tumor, and chemotherapy is often hampered by the development of angiogenesis. Therefore, suppression of angiogenesis is considered a potential treatment approach. Tannic acid (TA), a natural polyphenol, has been demonstrated to have anticancer properties in a variety of cancers; however, its angiogenic properties have yet to be studied. Hence, in the current study, we investigated the antiproliferative and antiangiogenic effects of TA on NSCLC cells. The (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) (MTS) assay revealed that TA induced a dose- and time-dependent decrease in the proliferation of A549 and H1299 cells. However, TA had no significant toxicity effects on human bronchial epithelial cells. Clonogenicity assay revealed that TA suppressed colony formation ability in NSCLC cells in a dose-dependent manner. The anti-invasiveness and antimigratory potential of TA were confirmed by Matrigel and Boyden chamber studies, respectively. Importantly, TA also decreased the ability of human umbilical vein endothelial cells (HUVEC) to form tube-like networks, demonstrating its antiangiogenic properties. Extracellular vascular endothelial growth factor (VEGF) release was reduced in TA-treated cells compared to that in control cells, as measured by the enzyme-linked immunosorbent assay (ELISA). Overall, these results demonstrate that TA can induce antiproliferative and antiangiogenic effects against NSCLC.

Progress in research of tumor infiltrating lymphocytes in pancreatic cancer

The 5-year survival rate of pancreatic cancer is less than 5%, and the only available treatments, surgery, chemotherapy, and chemoradiation, have shown limited effectiveness. Therefore, alternative treatment strategies are urgently needed. In recent years, tumor infiltrating lymphocyte (TIL) therapy has shown promising successes in the treatment of some types of solid tumors because of its diverse TCR clonality, superior tumor-homing ability, and low off-target toxicity. The significant association between a high TIL density in pancreatic cancer tissue and a good clinical outcome and success of pancreatic cancer-specific TIL expansion ex vivo potentiates the rationality of the TIL therapy in pancreatic cancer. However, there are still many challenges ahead, such as neoantigen screening, rapid cell expansion, and low cytotoxicity. This article reviews the recent advances and limitations of TIL therapy in pancreatic cancer and discusses its future directions.

Asiatic acid inhibits angiogenesis and vascular permeability through the VEGF/VEGFR2 signaling pathway to inhibit the growth and metastasis of breast cancer in mice

Anti-angiogenic medicines have been evaluated as anticancer therapies, however, their use remains limited in clinical practice due to associated adverse effects. Asiatic acid (AA) is known to have broad-spectrum anticancer properties, however, its effects on angiogenesis in breast cancer remain to be fully established. In this study, we analyzed the inhibitory effects of AA on angiogenesis using human umbilical vein endothelial cells (HUVECs) cultured in vitro and on the growth and metastasis of a subcutaneous breast cancer 4T1 tumor model and a lung metastasis model in vivo. AA significantly inhibited HUVECs proliferation, migration, and tube formation in vitro. In vivo, AA significantly reduced the microvascular density and blood vascular permeability in breast cancer tumors and inhibited growth and lung metastasis. AA inhibited the expression of vascular endothelial growth factor (VEGF) in HUVECs and subsequently downregulated the phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2) and its downstream target proteins including ERK1/2, Src, and FAK. These results indicate that AA significantly inhibits angiogenesis and blood vessel permeability through the VEGF/VEGFR2 signal axis to inhibit the growth and metastasis of breast cancer. Our data strongly demonstrate the potential applications of AA in the treatment of breast cancer.

The Effects of Physical Exercise on Tumor Vasculature: Systematic Review and Meta-analysis

A wealth of evidence supports an association between physical exercise, decreased tumor growth rate, and reduced risk of cancer mortality. In this context, the tumor vascular microenvironment may play a key role in modulating tumor biologic behavior. The present systematic review and meta-analysis aimed to summarize the evidence regarding the effects of physical exercise on tumor vasculature in pre-clinical studies. We performed a computerized research on the PubMed, Scopus, and EBSCO databases to identify pre-clinical studies that evaluated the effect of physical exercise on tumor vascular outcomes. Mean differences were calculated through a random effects model. The present systematic review included 13 studies involving 373 animals. From these, 11 studies evaluated chronic intratumoral vascular adaptations and 2 studies assessed the acute intratumoral vascular adaptations to physical exercise. The chronic intratumoral vascular adaptations resulted in higher tumor microvessel density in 4 studies, increased tumor perfusion in 2 studies, and reduced intratumoral hypoxia in 3 studies. Quantitatively, regular physical exercise induced an increased tumor vascularization of 2.13 [1.07, 3.20] (p<0.0001). The acute intratumoral vascular adaptations included increased vascular conductance and reduced vascular resistance, which improved tumor perfusion and attenuated intratumoral hypoxia. In pre-clinical studies, physical exercise seems to improve tumor vascularization.

Incomplete thermal ablation of tumors promotes increased tumorigenesis

PURPOSE

While systemic tumor-stimulating effects can occur following ablation of normal liver linked to the IL-6/HGF/VEGF cytokinetic pathway, the potential for tumor cells themselves to produce these unwanted effects is currently unknown. Here, we study whether partially treated tumors induce increased tumor growth post-radiofrequency thermal ablation (RFA).

METHODS

Tumor growth was measured in three immunocompetent, syngeneic tumor models following partial RFA of the target tumor (in subcutaneous CT26 and MC38 mouse colorectal adenocarcinoma, N = 14 each); and in a distant untreated tumor following partial RFA of target subcutaneous R3230 rat breast adenocarcinoma (N = 12). Tumor cell proliferation (ki-67) and microvascular density (CD34) was assessed. In R3230 tumors, in vivo mechanism of action was assessed following partial RFA by measuring IL-6, HGF, and VEGF expression (ELISA) and c-Met protein (Western blot). Finally, RFA was performed in R3230 tumors with adjuvant c-Met kinase inhibitor or VEGF receptor inhibitor (at 3 days post-RFA, N = 3/arm, total N = 12).

RESULTS

RFA stimulated tumor growth in vivo in residual, incompletely treated surrounding CT26 and MC38 tumor at 3-6 days (p < 0.01). In R3230, RFA increased tumor growth in distant tumor 7 days post treatment compared to controls (p < 0.001). For all models, Ki-67 and CD34 were elevated (p < 0.01, all comparisons). IL-6, HGF, and VEGF were also upregulated post incomplete tumor RFA (p < 0.01). These markers were suppressed to baseline levels with adjuvant c-MET kinase or VEGF receptor inhibition.

CONCLUSION

Incomplete RFA of a target tumor can sufficiently stimulate residual tumor cells to induce accelerated growth of distant tumors via the IL-6/c-Met/HGF pathway and VEGF production.

Combinatorial therapy in tumor microenvironment: Where do we stand?

The tumor microenvironment plays a pivotal role in tumor initiation and progression by creating a dynamic interaction with cancer cells. The tumor microenvironment consists of various cellular components, including endothelial cells, fibroblasts, pericytes, adipocytes, immune cells, cancer stem cells and vasculature, which provide a sustained environment for cancer cell proliferation. Currently, targeting tumor microenvironment is increasingly being explored as a novel approach to improve cancer therapeutics, as it influences the growth and expansion of malignant cells in various ways. Despite continuous advancements in targeted therapies for cancer treatment, drug resistance, toxicity and immune escape mechanisms are the basis of treatment failure and cancer escape. Targeting tumor microenvironment efficiently with approved drugs and combination therapy is the solution to this enduring challenge that involves combining more than one treatment modality such as chemotherapy, surgery, radiotherapy, immunotherapy and nanotherapy that can effectively and synergistically target the critical pathways associated with disease pathogenesis. This review shed light on the composition of the tumor microenvironment, interaction of different components within tumor microenvironment with tumor cells and associated hallmarks, the current status of combinatorial therapies being developed, and various growing advancements. Furthermore, computational tools can also be used to monitor the significance and outcome of therapies being developed. We addressed the perceived barriers and regulatory hurdles in developing a combinatorial regimen and evaluated the present status of these therapies in the clinic. The accumulating depth of knowledge about the tumor microenvironment in cancer may facilitate further development of effective treatment modalities. This review presents the tumor microenvironment as a sweeping landscape for developing novel cancer therapies.

Upregulation of Nogo-B by hypoxia inducible factor-1 and activator protein-1 in hepatocellular carcinoma

Nogo-B is an important regulator of tumor angiogenesis. Expression of Nogo-B is remarkably upregulated in multiple tumor types, especially hepatocellular carcinoma (HCC). Here, we show the transcriptional regulation mechanisms of Nogo-B in liver cancer. In response to hypoxia, expression of Nogo-B significantly increased in HCC tissues and cells. The distal hypoxia-responsive element in the promoter was essential for transcriptional activation of Nogo-B under hypoxic conditions, which is the specific site for hypoxia inducible factor-1α (HIF-1α) binding. In addition, Nogo-B expression was associated with c-Fos expression in HCC tissues. Nogo-B expression was induced by c-Fos, yet inhibited by a dominant negative mutant A-Fos. Deletion and mutation analysis of the predicted activator protein-1 binding sites revealed that functional element mediated the induction of Nogo-B promoter activity, which was confirmed by ChIP. These results indicate that HIF-1α and c-Fos induce the expression of Nogo-B depending on tumor microenvironments, such as hypoxia and low levels of nutrients, and play a role in upregulation of Nogo-B in tumor angiogenesis.

Plasmalemma vesicle-associated protein promotes angiogenesis in cholangiocarcinoma via the DKK1/CKAP4/PI3K signaling pathway

Cholangiocarcinoma (CCA) is aggressive and has poor clinical outcomes because of typically delayed diagnosis and a lack of effective non-surgical therapeutic options. Recent studies have shown that plasmalemma vesicle-associated protein (PLVAP) is related to angiogenesis in various tumors, and in vivo PLVAP targeting therapy has been proven effective against hepatocellular carcinoma and pancreatic cancer. The goal of this study was to determine the potential therapeutic utility of targeting PLVAP and thus angiogenesis in CCA and explore the underlying molecular mechanisms. We found that the PLVAP expression levels were significantly higher in CCA tissues when compared with matched adjacent non-tumor tissues obtained from a total of 90 CCA patients; higher expression levels of PLVAP were associated with shorter overall survival of patients. In addition, overexpression of PLVAP was associated with higher micro-vessel density in CCA tissues. In a PLVAP overexpressing CCA patient-derived xenograft model, a novel humanized anti-PLVAP antibody in combination with Gemcitabine plus Cisplatin was significantly inhibited tumor growth. Molecular analysis of CCA cells co-cultured with human umbilical vascular endothelial cells or human hepatic sinusoidal endothelial cells showed that Dickkopf-related protein 1 (DKK1) secreted by CCA cells activated the PI3K/Akt pathway after binding to its receptor, cytoskeleton-associated protein 4 (CKAP4), resulting in the upregulation of PLVAP. Thus, CCA cells increased the angiogenic potency of endothelial cells in a paracrine fashion. Consistently, patients bearing CKAP4 and PLVAP overexpressing tumors had a poor prognosis. In conclusion, the DKK1/CKAP4/PI3K/PLVAP pathway increases angiogenesis in CCA and is therefore a potential anti-angiogenic target.

Construction of a ceRNA Network and a Prognostic lncRNA Signature associated with Vascular Invasion in Hepatocellular Carcinoma based on Weighted Gene Co-Expression Network Analysis

Background: Understanding risk factors for vascular invasion (VI) is crucial for assessing the risk of recurrence and overall prognosis of hepatocellular carcinoma (HCC). This study aimed to construct a prognostic long non-coding RNA (lncRNA) signature and a ceRNA Network associated with vascular invasion in HCC. Methods: Differentially expressed genes (DEGs) of HCC patients associated with VI were identified by analyzing data from TCGA. Weighted gene co-expression network analysis (WGCNA) was used to identify associations between gene expression modules and clinical features. A VI-related prognostic lncRNA signature was then established using univariate, LASSO and multivariate Cox proportional hazards regression analyses. Based on the hub modules identified by the WGCNA, we constructed a VI-related lncRNA-miRNA-mRNA ceRNA network and screened hub lncRNAs for further research. Finally, we conducted in vitro and in vivo experiments to determine the biological roles of the identified hub gene BBOX1-AS1. Results: The key module related to VI and OS was identified using WGCNA, after which a prognostic model consisting of eight lncRNAs was established, and verified using time-dependent receiver operating characteristic (ROC) curve analysis. BBOX1-AS1 was confirmed to be highly expressed in HCC tissues, and its expression was significantly correlated with a poor prognosis. Silencing BBOX1-AS1 in vitro significantly suppressed the proliferation, migration and invasion of HCC cells. In vivo experiments demonstrated that knocking down of BBOX1-AS1 could result in significant decrease of tumor volume and tumor weight. Conclusions: The VI-related lncRNA signature established in this study can be used to predict the clinical outcomes of HCC patients. In addition, we constructed a VI-related lncRNA-miRNA-mRNA ceRNA network and demonstrated that BBOX1-AS1 might be a novel biomarker associated with VI in HCC.

The Stemness-High Human Colorectal Cancer Cells Promote Angiogenesis by Producing Higher Amounts of Angiogenic Cytokines via Activation of the Egfr/Akt/Nf-κB Pathway

Purpose: Cancer stem cells (CSCs) are responsible for cancer metastasis by stimulating tumor angiogenesis via various mechanisms. To elucidate the potential of the stemness-high human colorectal cancer (CRC) cells (i.e., CRCSCs) in activating angiogenesis, effects of the GATA6-overexpressing HCT-116 and HT-29 human CRC clones established previously by us in promoting the angiogenesis of human umbilical vein endothelial cells (HUVECs) were examined. Methods: Angiogenesis-promoting effects (i.e., migration, invasion, DNA synthesis, and tube formation) in HUVECs of the conditioned media (CM) from various human CRC clones were analyzed. MMP activities were assessed using a zymography assay. Western blotting and selective inhibitors were used to dissect the signaling pathway involved. IHC was used to examine the vascular density in tumor xenografts. Results: We found that the conditioned media (CM) collected from the GATA6-overexpressing clones enhanced angiogenesis of HUVECs more effectively which might be attributed partly to a higher MMP-9 production by HUVECs. Subsequently, elevated levels of IL-8 and VEGF-A were detected in the CM whose tube formation-enhancing activities were abolished by the co-treatment with either a VEGFR2 inhibitor or an IL-8 neutralizing antibody. Interestingly, increased production of these cytokines in the GATA6-overexpressing clones was due to an EGFR/AKT-mediated activation of NF-κB. Furthermore, not only were the levels of CD31 and endomucin but also the blood vessel density was much higher in the xenograft tumors grown from these clones. Conclusion: Our findings demonstrate that human CRCSCs promote a stronger angiogenesis by producing higher amounts of angiogenic factors through activation of the EGFR/AKT/NF-κB pathway.

The effects of vascularization on tumor development: A systematic review and meta-analysis of pre-clinical studies

PURPOSE

This review aimed to systematize and quantify the existing evidence about the effect of tumor vascularization on its growth, in preclinical studies.

METHODOLOGY

A computerized research on databases PubMed, Scopus and EBSCO was performed to identify studies that evaluate both the vascularization parameters and the development of the tumors in animal models and the mean differences were calculated through a random effects model.

RESULTS

Thirteen studies met the inclusion criteria and were included in the systematic review, of which, 6 studies were included in the meta-analysis. Besides tumor vascular density that all studies evaluated, 3 studies analysed the tumor perfusion, 2 studies the tumor hypoxia and 3 studies assessed the grade of vessel maturation. Most of the studies (11) related decreased tumor vascularization and a concomitant inhibition of tumor growth or metastasis development. Quantitatively, the decrease in tumor vascularization contributed to a significant decrease in the tumor growing rate of 5.23 (-9.20, -1.26).

CONCLUSION

A reduced level of tumor vascularization seems to be able to inhibit tumor growth and progression.

Identification of SARS-CoV-2 Proteins Binding Human mRNAs As a Novel Signature Predicting Overall Survival in Hepatocellular Carcinoma

The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the virus causing coronavirus disease 2019 (COVID-19), has been confirmed in cancers through binding specific mRNAs to invade human cells. Therefore, the aim of this study described here was to develop and validate novel SARS-CoV-2 proteins binding human mRNAs (SPBRs) signature to predict overall survival (OS) in hepatocellular carcinoma (HCC). Using multivariate Cox regression analysis, a set of SPBRs was identified to establish a multigene signature in the Cancer Genome Atlas repositories cohort. Furthermore, a nomogram was established based on the signature and clinical risk factors to improve risk stratification for individual patients. External validation was performed in the International Cancer Genome Consortium (ICGC) cohort. A six-SPBR signature was built to classify patients into two risk groups using a risk score with different OS in two cohorts (all p < 0.0001). Multivariate regression analysis demonstrated the signature was an independent predictor of HCC. Moreover, the signature presented an excellent diagnostic power in differentiating HCC and normal tissues. Gene set enrichment analysis demonstrated that high-risk group was closely enriched in cell cycle, DNA replication, microRNAs in cancer, and cytokine-cytokine receptor interaction. The novel signature demonstrated great clinical value in predicting the OS for patients with HCC, and will provide a good reference between cancer research and SARS-CoV-2 and help individualized treatment in HCC.

Hepatic Stellate Cells and Hepatocarcinogenesis

Hepatic stellate cells (HSCs) are a significant component of the hepatocellular carcinoma (HCC) tumor microenvironment (TME). Activated HSCs transform into myofibroblast-like cells to promote fibrosis in response to liver injury or chronic inflammation, leading to cirrhosis and HCC. The hepatic TME is comprised of cellular components, including activated HSCs, tumor-associated macrophages, endothelial cells, immune cells, and non-cellular components, such as growth factors, proteolytic enzymes and their inhibitors, and other extracellular matrix (ECM) proteins. Interactions between HCC cells and their microenvironment have become topics under active investigation. These interactions within the hepatic TME have the potential to drive carcinogenesis and create challenges in generating effective therapies. Current studies reveal potential mechanisms through which activated HSCs drive hepatocarcinogenesis utilizing matricellular proteins and paracrine crosstalk within the TME. Since activated HSCs are primary secretors of ECM proteins during liver injury and inflammation, they help promote fibrogenesis, infiltrate the HCC stroma, and contribute to HCC development. In this review, we examine several recent studies revealing the roles of HSCs and their clinical implications in the development of fibrosis and cirrhosis within the hepatic TME.

Oroxylin A suppresses ACTN1 expression to inactivate cancer-associated fibroblasts and restrain breast cancer metastasis

Tumor initiation and progression are not only ascribed to the behavior of cancer cells, but also profoundly influenced by the tumor microenvironment. Inside, cancer-associated fibroblasts (CAFs) have become key factors to accelerate growth and metastasis for the abundance in most solid tumors. Our group previously reported that Oroxylin A (OA), a flavone from Scutellaria Baicalensis Georgi, possess the ability to suppress growth and invasion of several tumor cells. However, the regulatory effect of OA on stromal microenvironment is poorly understood. In this study, breast cancer-induced fibroblasts and primary breast CAFs from MMTV-PyMT mice were used to evaluate the influence of OA on the activation of fibroblasts. Results showed that OA could decrease the expression of α-SMA, fibronectin, vimentin and matrix metalloproteinases (MMPs). Thus, OA-deactivated CAFs did not further promote the proliferation and invasion in breast cancer cells. In vivo experiments, OA could also impede tumor metastasis through exhausting progressive CAFs. Mechanically, OA could specifically bind ACTN1 and significantly inhibit its expression to prevent CAF activation. As a consequence, OA could decrease the phosphorylation of FAK and STAT3, and reduce the secretion of CCL2 in CAFs. Altogether, OA could remodel stromal microenvironment and it is a potential therapeutic agent in breast cancer.

Danger matrix molecules orchestrate CD14/CD44 signaling in cancer development

The tumor matrix together with inflammation and autophagy are crucial regulators of cancer development. Embedded in the tumor stroma are numerous proteoglycans which, in their soluble form, act as danger-associated molecular patterns (DAMPs). By interacting with innate immune receptors, the Toll-like receptors (TLRs), DAMPs autonomously trigger aseptic inflammation and can regulate autophagy. Biglycan, a known danger proteoglycan, can regulate the cross-talk between inflammation and autophagy by evoking a switch between pro-inflammatory CD14 and pro-autophagic CD44 co-receptors for TLRs. Thus, these novel mechanistic insights provide some explanation for the plethora of reports indicating that the same matrix-derived DAMP acts either as a promoter or suppressor of tumor growth. In this review we will summarize and critically discuss the role of the matrix-derived DAMPs biglycan, hyaluronan, and versican in regulating the TLR-, CD14- and CD44-signaling dialogue between inflammation and autophagy with particular emphasis on cancer development.

Cellular backpacks for macrophage immunotherapy

Adoptive cell transfers have emerged as a disruptive approach to treat disease in a manner that is more specific than using small-molecule drugs; however, unlike traditional drugs, cells are living entities that can alter their function in response to environmental cues. In the present study, we report an engineered particle referred to as a "backpack" that can robustly adhere to macrophage surfaces and regulate cellular phenotypes in vivo. Backpacks evade phagocytosis for several days and release cytokines to continuously guide the polarization of macrophages toward antitumor phenotypes. We demonstrate that these antitumor phenotypes are durable, even in the strongly immunosuppressive environment of a murine breast cancer model. Conserved phenotypes led to reduced metastatic burdens and slowed tumor growths compared with those of mice treated with an equal dose of macrophages with free cytokine. Overall, these studies highlight a new pathway to control and maintain phenotypes of adoptive cellular immunotherapies.

7‑Difluoromethyl‑5,4'‑dimethoxygenistein exerts anti‑angiogenic effects on acute promyelocytic leukemia HL‑60 cells by inhibiting the TLR4/NF‑κB signaling pathway

Angiogenesis plays an important role in the development and metastasis of tumors, and anti-angiogenesis agents are used to treat tumors. For example, the acute promyelocytic leukemia (APL) may be treated with arsenic trioxide. Angiogenesis in APL is a multi-step dynamic equilibrium process coordinated by various angiogenic stimulators and inhibitors, which play key roles in the occurrence, progression and chemosensitivity of this disease. Our research group previously synthesized 7-difluoromethyl-5,4′-dimethoxygenistein (DFMG), and found that it inhibits angiogenesis during atherosclerotic plaque formation. In the present study, the effect and mechanism of DFMG in angiogenesis induced by APL HL-60 cells was investigated using a chick embryo chorioallantoic membrane model and Matrigel tubule formation assays. The results obtained revealed an anti-angiogenesis effect of DFMG towards HL-60 cells. When the Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling pathway was inhibited, the anti-angiogenic effect of DFMG was further enhanced. However, when the TLR4/NF-κB signaling pathway was activated, the anti-angiogenic effect of DFMG was attenuated. These results demonstrated that DFMG inhibits angiogenesis induced by APL HL-60 cells, and provides insights into the mechanism by which DFMG inhibits the TLR4/NF-κB signaling pathway. In conclusion, in the present study, the anti-angiogenesis effect of DFMG on APL has been reported, and the mechanism by which DFMG induced the anti-angiogenesis effect was explored. These findings have provided a potential new drug candidate for the treatment of patients with APL.

Carcinoma and Sarcoma Microenvironment at a Glance: Where We Are

Cells and extracellular matrix (ECM) components represent the multifaceted and dynamic environment that distinguishes each organ. Cancer is characterized by the dysregulation of the composition and structure of the tissues, giving rise to the tumor milieu. In this review, we focus on the microenvironmental analysis of colorectal cancer (CRC) and rhabdomyosarcoma (RMS), two different solid tumors. While a lot is known about CRC environment, for RMS, this aspect is mostly unexplored. Following the example of the more complete CRC microenvironmental characterization, we collected and organized data on RMS for a better awareness of how tissue remodeling affects disease progression.

Inhibition of the PI3K-AKT-mTOR pathway suppresses the adipocyte-mediated proliferation and migration of breast cancer cells

Objective: Although it is well known that adipocyte significantly affects breast cancer progression, its mechanism has not been fully understood. Here, we analyzed the effect of adipocytes on breast cancer progression including cell proliferation and migration. Materials and Methods: We treated the conditioned media obtained from mouse 3T3-L1-derived or human adipose tissue-derived mesenchymal stem cells (hAMSC)-derived adipocytes to breast cancer cells, MCF-7 and MDA-MB-231. And then, cells viability and proliferation were analyzed using MTT assays and colony forming assays, respectively. Also mRNA expression of inflammatory cytokines and proteins expression in main signal pathway were analyzed by RT-qPCR and immunoblotting, respectively. Results: Adipocyte-derived conditioned media increased the proliferation and migration of MCF-7 and MDA-MB-231 cells while little effects in a human normal immortalized mammary epithelial cell line MCF10A. In addition, adipocyte-derived conditioned media induced phosphorylation of AKT and mTOR and upregulated the expression of target genes of the PI3K-AKT-mTOR pathway including IL6, IL1β, IL1α and TNFα in breast cancer cells. Furthermore, BEZ235 a dual inhibitor of PI3K and mTOR significantly decreased the adipocyte-mediated the proliferation and migration of breast cancer cells. Conclusion: Adipocyte-derived conditioned media enhance the proliferation and migration of breast cancer cells through the PI3K-AKT-mTOR pathway, supporting the importance of heterotypic interactions between breast cancer cells and adipocytes in the tumor microenvironment.

Pathologic assessment of tumor-associated macrophages and their histologic localization in invasive breast carcinoma

BACKGROUND

Tumor-associated macrophages (TAMs) are important in regulating cross-talk between tumor cells and tumor microenvironment. TAMs are involved in multiple steps of tumor progression and invasion. This study aimed to compare CD163 expression with the widely used CD68 pan-macrophage marker in invasive breast carcinoma. Furthermore, it focused on assessing the significance of TAMs localization in relation to clinicopathological parameters.

RESULTS

CD68 and CD163 immunohistochemical expressions within TAMs infiltrating both tumor nest (TN) and tumor stroma (TS) were evaluated in 60 specimens with invasive breast carcinoma. High CD68-positive stromal TAMs was significantly related to larger tumor, nodal metastasis and vascular invasion (p = 0.003, 0.037, 0.032, respectively), whereas high CD163-positive stromal TAMs was significantly related to larger tumors, nodal metastasis, stage III tumors, vascular invasion, estrogen receptor (ER) negativity, and triple-negative subtype (p = 0.023, < 0.001, 0.001, 0.022, 0.002, 0.017, respectively). On multivariate analysis, high CD68-positive TAMs infiltrating TS was significantly associated with larger tumor and positive nodal metastasis (p = 0.006 and 0.016, respectively), whereas high CD163 TAMs density within TS was significantly associated with positive vascular invasion, nodal metastasis, and molecular subtypes (p = 0.003, 0.001, and 0.009, respectively).

CONCLUSION

TAMs within tumor stroma and tumor nest have different levels of association with poor prognostic parameters. So, it is of great importance to consider the histologic localization of TAMs in addition to the degree of TAMs infiltration.

Cancer Modeling-on-a-Chip with Future Artificial Intelligence Integration

Cancer is one of the leading causes of death worldwide, despite the large efforts to improve the understanding of cancer biology and development of treatments. The attempts to improve cancer treatment are limited by the complexity of the local milieu in which cancer cells exist. The tumor microenvironment (TME) consists of a diverse population of tumor cells and stromal cells with immune constituents, microvasculature, extracellular matrix components, and gradients of oxygen, nutrients, and growth factors. The TME is not recapitulated in traditional models used in cancer investigation, limiting the translation of preliminary findings to clinical practice. Advances in 3D cell culture, tissue engineering, and microfluidics have led to the development of "cancer-on-a-chip" platforms that expand the ability to model the TME in vitro and allow for high-throughput analysis. The advances in the development of cancer-on-a-chip platforms, implications for drug development, challenges to leveraging this technology for improved cancer treatment, and future integration with artificial intelligence for improved predictive drug screening models are discussed.

Growth hormone in the tumor microenvironment

Tumor development is a multistep process whereby local mechanisms enable somatic mutations during preneoplastic stages. Once a tumor develops, it becomes a complex organ composed of multiple cell types. Interactions between malignant and non-transformed cells and tissues create a tumor microenvironment (TME) comprising epithelial cancer cells, cancer stem cells, non-tumorous cells, stromal cells, immune-inflammatory cells, blood and lymphatic vascular network, and extracellular matrix. We review reports and present a hypothesis that postulates the involvement of growth hormone (GH) in field cancerization. We discuss GH contribution to TME, promoting epithelial-to-mesenchymal transition, accumulation of unrepaired DNA damage, tumor vascularity, and resistance to therapy. Arch Endocrinol Metab. 2019;63(6):568-75.

Jumonji domain-containing 6 (JMJD6) identified as a potential therapeutic target in ovarian cancer

Jumonji domain-containing 6 (JMJD6) is a candidate gene associated with tumorigenesis, and JMJD6 overexpression predicts poor differentiation and unfavorable survival in some cancers. However, there are no studies reporting the expression of JMJD6 in ovarian cancer, and no JMJD6 inhibitors have been developed and applied to targeted cancer therapy research. In the present study, we found that the high expression of JMJD6 in ovarian cancer was correlated with poor prognosis in ovarian cancer. A potential inhibitor (SKLB325) was designed based on the crystal structure of the jmjC domain of JMJD6. This molecule significantly suppressed proliferation and induced apoptosis in a dose-dependent manner in SKOV3 cell lines as detected by CCK-8 cell proliferation assays and flow cytometry. A Matrigel endothelial tube formation assay showed that SKLB325 inhibited capillary tube organization and migration in HUVECs in vitro. We also observed that JMJD6 colocalized with p53 protein in the nucleus, with mRNA and protein expression of p53 as well as its downstream effectors significantly increasing both in vitro and in intraperitoneal tumor tissues treated with SKLB325. In addition, SKLB325 significantly reduced the intraperitoneal tumor weight and markedly prolonged the survival of tumor-bearing mice. Taken together, our findings suggest that JMJD6 may be a marker of poor prognosis in ovarian cancer and that SKLB325 may be a potential candidate drug for the treatment of ovarian cancer.

Elevated pre-existing lymphocytic infiltrates in tumour stroma predict poor prognosis in resectable urothelial carcinoma of the bladder

AIMS

Lymphocytic infiltrates are predominantly distributed in the tumour stroma, and represents the tumour-related immune response. The aim of this study was to elucidate the prognostic value of stromal lymphocytic infiltrates (SLI) in resectable urothelial carcinoma of the bladder (UCB).

METHODS AND RESULTS

The prognostic significance of SLI in UCB was assessed in a discovery cohort (n = 226; 60 deaths) and in a validation cohort (n = 417; 103 deaths). SLI was categorised into intense (≥50% SLI) and non-intense (<50% SLI). A multivariable Cox model was used to analyse the associations of SLI score with overall survival (OS) and disease-free survival. Immunofluorescence staining was used to examine the composition and phenotypes of SLI. The median follow-up times were 58.1 and 64.9 months in the discovery and validation cohorts, respectively. SLI was intense in 38.1% of patients in the discovery cohort and in 20.9% of patients in the validation cohort (P < 0.001). SLI score had independent prognostic value for OS [hazard ratio (HR) 2.132; P = 0.016] and disease-specific survival (DSS) (HR 1.952; P = 0.04) in the discovery cohort, which was confirmed in the validation cohort (OS: HR 1.636; P = 0.023; DSS: HR 1.627; P = 0.029). SLI score was positively associated with histological grade, tumour stage and lymph node status in both cohorts. Moreover, in the stroma, SLI displayed a broad spectrum of inhibitory immune cells, by expressing several major immune checkpoint molecules, i.e. programmed cell death protein 1, programmed death-ligand 1, indoleamine 2,3-dioxygenase, and T-cell immunoglobulin and mucin domain 3.

CONCLUSION

Intense pre-existing SLI was validated as a reliable marker of poorer prognosis for survival in UCB patients, which may add to the prognostic significance of the TNM classification.

Synthesis, anticancer activity, structure–activity relationship and binding mode of interaction studies of substituted pentanoic acids

Aim: Simultaneous inhibition of MMP-2 and HDAC8 may be an effective strategy to target cancer. Methodology: In continuation of our earlier efforts, a series of substituted pentanoic acids (1–18) were synthesized and checked for their biological activity along with some earlier reported compounds (19 –35). Results: Compounds 18 and 31 were found to induce apoptosis effectively in a dose-dependent fashion in Jurkat-E6.1 cell line. They reduced the expression of both MMP-2 and HDAC8 effectively. 31 also produced prominent intensity of fluorescence to bring nick in Jurkat-E6.1 cells. 31 also showed cellular arrest in sub-G0 phase. Conclusion: Such compounds may be useful to battle against cancer.

Post-transcriptional regulation of miRNA-15a and miRNA-15b on VEGFR gene and deer antler cell proliferation

Background

Deer antler is the only regenerative organ in mammals, the regeneration of antler is not only the regeneration of bone tissue, but also accompanied by the regeneration of nerves, blood vessels and so on. The purpose of the current study was to explore the effect of miRNA-15a and miRNA-15b on the regulation of sika deer vascular endothelial growth factor receptor (VEGFR) during rapid antler growth.

Materials and methods

The VEGFR 3′-UTR was analyzed by bioinformatics software to identify the highly matched miRNAs. After transfected with miRNA mimics, the expression of selected miRNAs were measured by RT-qPCR and the relative expression level of VEGFR protein was detected by Western Blot. Dual-luciferase activity assay was used to determine the target relationship between VEGFR and miRNAs. The cartilage cell proliferation and telomerase activity were measured by MTT kit and TRAP assay, respectively.

Results

The VEGFR 3′-UTR contains a binding site for miRNA-15a and miRNA-15b. Over-expression of miRNA-15a and miRNA-15b, which significantly reduced the expression level of VEGFR protein, inhibited the proliferation of cartilage cells, and decreased the telomerase activity of cartilage cells in vitro.

Conclusion

miRNA-15a and miRNA-15b represent novel regulatory factors of VEGFR expression in deer antler.

Overview of tissue kallikrein and kallikrein-related peptidases in breast cancer

The kallikrein family comprises tissue kallikrein and 14 kallikrein-related peptidases (KLKs) recognized as a subgroup of secreted trypsin- or chymotrypsin-like serine proteases. KLKs are expressed in many cellular types where they regulate important physiological activities such as semen liquefaction, immune response, neural development, blood pressure, skin desquamation and tooth enamel formation. Tissue kallikrein, the oldest member and kinin-releasing enzyme, and KLK3/PSA, a tumor biomarker for prostate cancer are the most prominent components of the family. Additionally, other KLKs have shown an abnormal expression in neoplasia, particularly in breast cancer. Thus, increased levels of some KLKs may increase extracellular matrix degradation, invasion and metastasis; other KLKs modulate cell growth, survival and angiogenesis. On the contrary, KLKs can also inhibit angiogenesis and produce tumor suppression. However, there is a lack of knowledge on how KLKs are regulated in tumor microenvironment by molecules present at the site, namely cytokines, inflammatory mediators and growth factors. Little is known about the signaling pathways that control expression/secretion of KLKs in breast cancer, and further how activation of PAR receptors may contribute to functional activity in neoplasia. A better understanding of these molecular events will allow us to consider KLKs as relevant therapeutic targets for breast cancer.

Axl signaling is an important mediator of tumor angiogenesis

The growth of primary tumors as well as metastatic neoplastic lesions is strongly dependent on the cancer cells’ ability to initiate their own vascular network. This process, angiogenesis, which involves the proliferation, migration, and invasion of endothelial cells, is critically dependent on a variety of signaling molecules that target specific receptors, most notably tyrosine kinases. One receptor tyrosine kinase associated with poor prognosis, metastasis, and outcome in a variety of tumor types, is Axl. Although the role of Axl in tumor cell migration and invasion are well recognized, little is known about the involvement of Axl signaling in the initiation of angiogenesis. Here, we show that Axl inhibition in tumor cells decreases the secretion of pro-angiogenic factors and impairs functional properties of endothelial cells in vitro and in vivo. These data indicate that Axl signaling is an important contributor to tumor angiogenesis.

Tumor mechanisms of resistance to immune attack

The immune system plays a key role in the interactions between host and tumor. Immune selection pressure is a driving force behind the sculpting and evolution of malignant cancer cells to escape this immune attack. Several common tumor cell-based mechanisms of resistance to immune attack have been identified and can be broadly categorized into three main classes: loss of antigenicity, loss of immunogenicity, and creation of an immunosuppressive microenvironment. In this review, we will discuss in detail the relevant literature associated with each class of resistance and will describe the relevance of these mechanisms to human cancer patients. To conclude, we will outline the implications these mechanisms have for the treatment of cancer using currently available therapeutic approaches. Immunotherapy has been a successful addition to current treatment approaches, but many patients either do not respond or quickly become resistant. This reflects the ability of tumors to continue to adapt to immune selection pressure at all stages of development. Additional study of immune escape mechanisms and immunotherapy resistance mechanisms will be needed to inform future treatment approaches.

S-nitrosylation and its role in breast cancer angiogenesis and metastasis

S-nitrosylation, the modification by nitric oxide of free sulfhydryl groups in cysteines, has become an important regulatory mechanism in carcinogenesis and metastasis. S-nitrosylation of targets in tumor cells contributes to metastasis regulating epithelial to mesenchymal transition, migration and invasion. In the tumor environment, the role of S-nitrosylation in endothelium has not been addressed; however, the evidence points out that S-nitrosylation of endothelial proteins may regulate angiogenesis, adhesion of tumor cells to the endothelium, intra and extravasation of tumor cells and contribute to metastasis.

Activated Wnt signaling promotes growth and progression of AFP-producing gastric cancer in preclinical models

Background

Characterized by elevated AFP levels in serum, AFP-producing gastric cancer (APGC) is a very special type of gastric cancer (GC) that is difficult to treat and has poor prognosis. However, little is known about the role of AFP in GC, which was investigated in this study with in vitro and in vivo experiments.

Methods

APGC cells were established with lentivirus infection and validated by PCR assay and ELISA in HCG27 and AGS cells. Cell growth, migration, and invasion were determined by CCK8, transwell assays, and animal experiments. RNA sequencing, Western blot, dual-luciferase-reporter assays, and RNA interference were employed to understand mechanisms underlying AFP activity, followed by therapeutic investigations for APGC.

Results

APGC cells featured significantly increased AFP levels in cellular supernatants. AFP potentiated growth and aggression in GC cell lines and their derived xenografts. Wnt-signaling activation was responsible for AFP function, indicated by decreased Axin 1 and pGSK3β, followed by cascade activation of β-catenin, downstream transcription factors TCF1/TCF7, and the target gene – c-Myc. Wnt-signaling blockade by Axin 1 rescue or pathway inhibitor XAV939 reversed AFP function, suggesting the potential therapeutic value of APGC.

Conclusion

AFP played a critical role in APGC through activating Wnt signaling, and targeting Wnt pathways might be a promising strategy against APGC.

Krüppel like factor 6 splice variant 1 (KLF6-SV1) overexpression recruits macrophages to participate in lung cancer metastasis by up-regulating TWIST1

The aim of this study was to investigate the mechanism by which KLF6-SV1 promoted lung cancer metastasis through tumor-associated macrophages (TAMs). Plasmid transfection was used to construct cells that upregulated or silenced gene. Tumor-bearing mouse model was established using A549 cells. SP staining was performed to detect the CD163 and CD68. Six-well plates and Transwell chamber were used for co-culture of lung cancer A549 cells and macrophages. CCK-8 and Transwell assay were applied to detected the cell viability and migration respectively. Protein and mRNA were tested by Western blot and quantitative real-time polymerase chain reaction (qRT-PCR).KLF6-SV1 overexpression promoted the expression levels of TWIST1 and CCL2, and also induce macrophage polarization to M2 and epithelial-mesenchymal transition (EMT). In vitro experiments showed that KLF6-SV1 might regulate the migration of lung cancer cells by regulating the expression of TWIST1 and CCL-2. M2 macrophages did not affect the expression of KLF6-SV1, TWIST1 and CCL-2. The co-culture system could up-regulate the EMT of A549 cells.Overexpression of KLF6-SV1 promoted the expression of TWIST1 and CCL2, and up-regulation of TWIST1 expression might promote the infiltration of M2 macrophages, which promoted the involvement of EMT in the metastasis of lung cancer cells.

Challenges facing antiangiogenesis therapy: The significant role of hypoxia-inducible factor and MET in development of resistance to anti-vascular endothelial growth factor-targeted therapies

It is now fully recognized that along with multiple physiological functions, angiogenesis is also involved in the fundamental process and pathobiology of several disorders including cancer. Recent studies have fully established the role of angiogenesis in cancer progression as well as invasion and metastasis. Consequently, many therapeutic agents such as monoclonal antibodies targeting angiogenesis pathway have been introduced in clinic with the hope for improving the outcomes of cancer therapy. Bevacizumab (Avastin®) was the first anti-vascular endothelial growth factor (VEGF) targeting monoclonal antibody developed with this purpose and soon received its accelerated US Food and Drug Administration (FDA) approval for treatment of patients with metastatic breast cancer in 2008. However, the failure to meet expecting results in different follow-up studies, forced FDA to remove bevacizumab approval for metastatic breast cancer. Investigations have now revealed that while suppressing VEGF pathway initially decreases tumor progression rate and vasculature density, activation of several interrelated pathways and signaling molecules following VEGF blockade compensate the insufficiency of VEGF and initially blocked angiogenesis, explaining in part the failure observed with bevacizumab single therapy. In present review, we introduce some of the main pathways and signaling molecules involved in angiogenesis and then propose how their interconnection may result in development of resistance to bevacizumab.

Effect of Stromal Cells in Tumor Microenvironment on Metastasis Initiation

The cellular environment where tumor cells reside is called the tumor microenvironment (TME), which consists of borders, blood vessels, lymph vessels, extracellular matrix (ECM), stromal cells, immune/inflammatory cells, secreted proteins, RNAs and small organelles. By dynamically interacting with tumor cells, stromal cells participate in all stages of tumor initiation, progression, metastasis, recurrence and drug response, and consequently, affect the fate of patients. During the processes of tumor evolution and metastasis initiation, stromal cells in TME also experience some changes and play roles in both the suppression and promotion of metastasis, while the overall function of stromal cells is beneficial for cancer cell survival and movement. In this review, we examine the effects of stromal cells in TME on metastasis initiation, including angiogenesis, epithelial-mesenchymal transition (EMT) and invasion. We also highlight functions of proteins, RNAs and small organelles secreted by stromal cells in their influences on multiple stages of tumor metastasis.

Renin-angiotensin inhibitors reprogram tumor immune microenvironment: A comprehensive view of the influences on anti-tumor immunity

Renin-angiotensin system inhibitors (RASi) have shown potential anti-tumor effects that may have a significant impact in cancer therapy. The components of the renin-angiotensin system (RAS) including both, conventional and alternative axis, appear to have contradictory effects on tumor biology. The mechanisms by which RASi impair tumor growth extend beyond their function of modulating tumor vasculature. The major focus of this review is to analyze other mechanisms by which RASi reprogram the tumor immune microenvironment. These involve impairing hypoxia and acidosis within the tumor stroma, regulating inflammatory signaling pathways and oxidative stress, modulating the function of the non-cellular components and immune cells, and regulating the cross-talk between kalli krein kinin system and RAS.