Expression of VCAM-1, ICAM-1, E- and P-selectin and tumour-associated macrophages in renal cell carcinoma

Systematic pan-cancer analysis insights into ICAM1 as an immunological and prognostic biomarker

Intercellular adhesion molecule 1 (ICAM1) is a cell surface adhesion glycoprotein in the immunoglobulin supergene family. It is associated with several epithelial tumorigenesis processes, as well as with inflammation. However, the function of ICAM1 in the prognosis of tumor immunity is still unclear. This study aimed to examine the immune function of ICAM1 in 33 tumor types and to investigate the prognostic value of tumors. Using datasets from the Cancer Genome Atlas (TCGA), Genotype Tissue Expression (GTEx), Cancer Cell Lines Encyclopedia (CCLE), Human Protein Atlas (HPA), and cBioPortal, we investigated the role of ICAM1 in tumors. We explored the potential correlation between ICAM1 expression and tumor prognosis, gene mutations, microsatellite instability, and tumor immune cell levels in various cancers. We observed that ICAM1 is highly expressed in multiple malignant tumors. Furthermore, ICAM1 is negatively or positively associated with different malignant tumor prognoses. The expression levels of ICAM1 were correlated with the tumor mutation burden (TMB) in 11 tumors and with MSI in eight tumors. ICAM1 is a gene associated with immune infiltrating cells, such as M1 macrophages and CD8+ T cells in gastric and colon cancer. Meanwhile, the expression of ICAM1 is associated with several immune-related functions and immune-regulation-related signaling pathways, such as the chemokine signaling pathway. Our study shows that ICAM1 can be used as a prognostic biomarker in many cancer types because of its function in tumorigenesis and malignant tumor immunity.

Impact of Fibrinogen, Fibrin Thrombi, and Thrombin on Cancer Cell Extravasation Using In Vitro Microvascular Networks

A bidirectional association exists between metastatic dissemination and the hypercoagulable state associated with many types of cancer. As such, clinical studies have provided evidence that markers associated with elevated levels of coagulation and fibrinolysis correlate with decreased patient survival. However, elucidating the mechanisms underpinning the effects of different components of the coagulation system on metastasis formation is challenging both in animal models and 2D models lacking the complex cellular interactions necessary to model both thrombosis and metastasis. Here, an in vitro, 3D, microvascular model for observing the formation of fibrin thrombi is described, which is in turn used to study how different aspects of the hypercoagulable state associated with cancer affect the endothelium. Using this platform, cancer cells expressing ICAM-1 are shown to form a fibrinogen-dependent bridge and transmigrate through the endothelium more effectively. Cancer cells are also demonstrated to interact with fibrin thrombi, using them to adhere, spread, and enhance their extravasation efficiency. Finally, thrombin is also shown to enhance cancer cell extravasation. This system presents a physiologically relevant model of fibrin clot formation in the human microvasculature, enabling in-depth investigation of the cellular interactions between cancer cells and the coagulation system affecting cancer cell extravasation.

The effects of morphine on vascular cell adhesion molecule 1(VCAM-1) concentration in lung cancer cells

OBJECTIVE

Vascular cell adhesion molecule 1 (VCAM-1) plays an important role in tumour cell adhesion to endothelial cells. Some tumour cells also show aberrant expression of VCAM-1. Toll-like receptor 4 (TLR4) agonists can increase VCAM-1 expression. Morphine, an opioid receptor agonist, is also a TLR4 agonist. In this study, we aimed to evaluate whether morphine increase VCAM-1 expression in a TLR4 dependent manner.

METHODS

A549 Lung cancer cells were treated with different doses of morphine and TLR4 antagonist for 24 and 48 h. TLR4 gene expression was evaluated by real-time PCR and VCAM-1 protein was measured by the enzyme-linked immunosorbent assay (ELISA).

RESULTS

Morphine enhanced mRNA expression of TLR4 and protein level of VCAM-1. TLR4 antagonist returned VCAM-1expression to the normal level.

CONCLUSION

Morphine effects VCAM-1expressions via TLR4 in lung cancer cell line.

The development of multifunctional sulfated polyguluronic acid-based polymeric micelles for anticancer drug delivery

Numerous disseminated tumor cells specifically overexpress P-selectin. Therefore, it was thought to be a potential target for tumor therapy. Herein, we described a novel P-selectin-targeted glycosyl ligand-sulfated polyguluronic acid (PGS), as an oriented carrier of P-selectin-targeted drug delivery system. Specifically, the PGS-SS-DOX polymeric micelles were constructed to confirm the practicability of the PGS carrier as a new P-selectin-targeted ligand. PGS-SS-DOX micelles comprised P-selectin-targeted PGS, doxorubicin (DOX) as an anticarcinogen, and pH/redox dual-sensitive bio-linker facilitating drug release in tumor tissues. In vitro and in vivo data showed that PGS-SS-DOX micelles significantly increased tumor cell killing capacity and exhibited a favorable biocompatibility comparison with Free-DOX. This work proved that PGS was an ideal low immunogenic, biodegradable drug carrier for the delivery of anti-cancer drugs. The facile PGS-SS-drug micelle system provided enormous opportunities for treating disseminated tumors utilizing many irreplaceable anticarcinogens.

Structural characterization of a P-selectin and EGFR dual-targeting fucoidan from Sargassum fusiforme

In this study, we obtained fucoidans SFP, SHP, STP, and FVP from Sargassum fusiforme, Sargassum horneri, Sargassumthunbergii, and Fucus vesiculosus, respectively. Chitosan/fucoidan nanoparticles (Cs/F NPs) were prepared using the fucoidans mentioned above. SFP NPs and SHP NPs showed strong binding abilities to P-selectin and epithelial growth factor receptor (EGFR). Given the yields from the alga, SFP was first selected to explore the structural characteristics of the P-selectin and EGFR dual-targeting fucoidan. SFP had an estimated molecular weight of 739 kDa and was mainly composed of galactose (26.57%, mol%) and fucose (66.81%), with minor amounts of mannose (2.54%), glucosamine (0.42%), and glucose (3.66%). Galactose and fucose accounted for thevast majority. Further investigation, including methylation analysis, one- and two-dimensional nuclear magnetic resonance, and mass spectroscopy, was performed to reveal the fine structure of SFP. The results indicated that SFP mainly consisted of → 3)-α-l-Fucp-(1→, →4)-α-l-Fucp-(1→, →3,4)-α-l-Fucp-(1→, →3)-β-d-Galp-(1→, and minor → 6)-β-d-Galp-(1→, partially sulfated at the C-4 of → 3)-α-l-Fucp-(1→, C-3 of → 4)-α-l-Fucp-(1→, C-3 of → 6)-β-d-Galp-(1→, and C-6 of → 3)-β-d-Galp-(1 → . Sulfated fuco- and galactofuco-segments formed the branches.

Expression of Adhesion Molecules in a Gastroduodenal Reflux Murine Model

BACKGROUND

Various adhesion molecules including intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) have been shown to play a role in inflammation as well as contribute to tumor progression and prognosis. We hypothesized that gastroduodenal reflux upregulates ICAM-1 and VCAM-1 expression in the distal esophagus, serving as possible early markers of pathologic esophageal disease.

METHODS

Normal human esophageal epithelial cells (HET1A), Barrett's cells (CPB), and esophageal adenocarcinoma cells (FLO1 and OE33) were treated with deoxycholic acid (DCA) at increasing concentrations for 24 hours. Adhesion molecule expression was assessed using immunoblotting. A surgical mouse reflux model was generated by performing a side-to-side anastomosis between the gastroesophageal junction and the first portion of the duodenum (duodeno-gastroesophageal anastomosis, DGEA). Esophageal sections were evaluated using H&E staining, immunohistochemistry, and immunofluorescence.

RESULTS

DCA induced a significant increase in ICAM-1 and VCAM-1 expression in HET1A, CPB, FLO1, and OE33 cells. Animals undergoing DGEA demonstrated a significant increase in mucosal hyperplasia (p<0.0001) and cellular proliferation (p<0.0001) compared to control animals. Immunofluorescence and western blot analysis of the lower esophagus demonstrated significant upregulation of ICAM-1 (p=0.005), with no change in VCAM-1 expression (p=0.82).

CONCLUSIONS

Our results reveal that ICAM-1 and VCAM-1 are upregulated in response to in vitro reflux treatment of normal esophageal epithelial cells. However, upon investigation using a mouse reflux model, ICAM-1 is noticeably upregulated without a concomitant increase in VCAM-1. These findings identify ICAM-1, but not VCAM-1, as a potential player in early esophageal disease developing from chronic reflux exposure.

Secretory Phospholipase A2 Inhibition Attenuates Adhesive Properties of Esophageal Barrett's Cells

BACKGROUND

Gastroesophageal reflux and Barrett's esophagus are significant risk factors for the development of esophageal adenocarcinoma. Group IIa secretory phospholipase A₂ (sPLA₂) catalyzes the production of various proinflammatory metabolites and plays a critical role in promoting reflux-induced inflammatory changes within the distal esophagus. We hypothesized that inhibition of sPLA₂ in human Barrett's cells would attenuate adhesion molecule expression via decreased activation of nuclear factor kappa B (NF-κB) and decrease cell proliferation, possibly mitigating the invasive potential of Barrett's esophagus.

MATERIALS AND METHODS

Normal human esophageal epithelial cells (HET1A) and Barrett's cells (CPB) were assayed for baseline sPLA₂ expression. CPB cells were treated with a specific inhibitor of sPLA₂ followed by tumor necrosis factor-α. Protein expression was evaluated using immunoblotting. Cell proliferation was assessed using an MTS cell proliferation assay kit. Statistical analysis was performed using the Student's t-test or analysis of variance, where appropriate.

RESULTS

CPB cells demonstrated higher baseline sPLA₂ expression than HET1A cells (P = 0.0005). Treatment with 30 μM sPLA₂ inhibitor significantly attenuated intercellular adhesion molecule-1 (P = 0.004) and vascular cell adhesion molecule-1 (P < 0.0001) expression as well as decreased NF-κB activation (P = 0.002). sPLA₂ inhibition decreased cell proliferation in a dose-dependent manner (P < 0.001 for 15, 20, and 30 μM doses).

CONCLUSIONS

sPLA₂ inhibition in human Barrett's cells decreases cellular adhesive properties and NF-κB activation as well as decreases cell proliferation, signifying downregulation of the inflammatory response and possible attenuation of cellular malignant potential. These findings identify sPLA₂ inhibition as a potential chemopreventive target for premalignant lesions of the esophagus.

Intercellular Adhesion Molecule-1 as Target for CAR-T-Cell Therapy of Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) comprises lethal malignancies with limited treatment options. Chimeric antigen receptor T (CAR-T) cell therapy is an effective immunotherapeutic strategy that has demonstrated unprecedented efficacy in the treatment of hematological malignancies but has shown limited success in the management of some solid tumors. Many malignant tumors are related to increased expression of intercellular adhesion molecule-1 (ICAM1), providing a rationale for ICAM1-specific immunotherapies for the treatment of cancer. Here, we validated the expression of ICAM1 in TNBC tissues. Subsequently, we generated a phage-displayed single-chain variable fragment (scFv) library using splenocytes from ICAM1-immunized mice and selected a novel ICAM1-specific scFv, mG2-scFv. Using mG2-scFv as the extracellular antigen binding domain, we constructed ICAM1-specific CAR-T cells and demonstrated the robust and specific killing of TNBC cell lines in vitro. Most importantly, in the TNBC mouse model, ICAM1-specific CAR-T cells significantly reduced the growth of the TNBC tumor, resulting in long-term remission and improved survival. Together, these results indicated that ICAM1-specific CAR-T cells have high therapeutic potential against ICAM1-positive TNBC tumors.

Co-Delivery of Natural Compounds with a Dual-Targeted Nanoparticle Delivery System for Improving Synergistic Therapy in an Orthotopic Tumor Model

Various natural compounds including epigallocatechin gallate (EGCG) and curcumin (CU) have potential in developing anticancer therapy. However, their clinical use is commonly limited by instability and low tissue distribution. EGCG and CU combined treatment can improve the efficacy with synergistic effects. To improve the synergistic effect and overcome the limitations of low tissue distribution, we applied a dual cancer-targeted nanoparticle system to co-deliver EGCG and CU. Nanoparticles were composed of hyaluronic acid, fucoidan, and poly(ethylene glycol)-gelatin to encapsulate EGCG and CU. Furthermore, a dual targeting system was established with hyaluronic acid and fucoidan, which were used as agents for targeting CD44 on prostate cancer cells and P-selectin in tumor vasculature, respectively. Their effect and efficacy were investigated in prostate cancer cells and a orthotopic prostate tumor model. The EGCG/CU-loaded nanoparticles bound to prostate cancer cells, which were uptaken more into cells, leading to a better anticancer efficiency compared to the EGCG/CU combination solution. In addition, the releases of EGCG and CU were regulated by their pH value that avoided the premature release. In mice, treatment of the cancer-targeted EGCG/CU-loaded nanoparticles significantly attenuated the orthotopic tumor growth without inducing organ injuries. Overall, the dual-targeted nanoparticle system for the co-delivery of EGCG and CU greatly improved its synergistic effect in cancer therapy, indicating its great potential in developing treatments for prostate cancer therapy.

Comparative STAT3-Regulated Gene Expression Profile in Renal Cell Carcinoma Subtypes

Renal cell carcinomas (RCC) are heterogeneous and can be further classified into three major subtypes including clear cell, papillary and chromophobe. Signal transducer and activator of transcription 3 (STAT3) is commonly hyperactive in many cancers and is associated with cancer cell proliferation, invasion, migration, and angiogenesis. In renal cell carcinoma, increased STAT3 activation is associated with increased metastasis and worse survival outcomes, but clinical trials targeting the STAT3 signaling pathway have shown varying levels of success in different RCC subtypes. Using RNA-seq data from The Cancer Genome Atlas (TCGA), we compared expression of 32 STAT3 regulated genes in 3 RCC subtypes. Our results indicate that STAT3 activation plays the most significant role in clear cell RCC relative to the other subtypes, as half of the evaluated genes were upregulated in this subtype. MMP9, BIRC5, and BCL2 were upregulated and FOS was downregulated in all three subtypes. Several genes including VEGFA, VIM, MYC, ITGB4, ICAM1, MMP1, CCND1, STMN1, TWIST1, and PIM2 had variable expression in RCC subtypes and are potential therapeutic targets for personalized medicine.

Novel Mesenchymal Stem Cell Strategy in Alleviating Toll-Like Receptor-4, p53 and Nrf2 Signaling in Isoproterenol-Induced Myocardial Infarction in Rat Model

Mesenchymal stem cells (MSCs) are multipotent stromal cells that merit the differentiation into various cell types. The present study was designed to test the hypothesis that the cardioprotective effect of MSCs transplantation and digoxin treatment is mediated via the regulation of messenger RNA gene expression of pro-inflammatory cytokines and apoptotic markers. Myocardial infarction was induced in Wistar rats via isoproterenol injection in a dose of (85 mg/kg, subcutaneously, twice at an interval of 24 h). Four weeks post-MSCs transplantation and digoxin treatment a significant reduction in serum cardiac markers, aspartate aminotransferase, creatine kinase-MB and troponine II was observed. Meanwhile, isoproterenol significantly reduced the gene and protein expression of the oxidative stress marker nuclear-related factor-2 (Nrf2) with a concomitant elevation in (MDA) level and inflammatory markers toll-like receptor-4 (TLR-4), intercellular adhesion molecules (ICAMs) and (VCAM-1). Moreover, apoptotic marker (P53) was significantly down-regulated. This was confirmed by histopathological investigations. It was hypothesized that MSCs transplantation was superior over digoxin treatment regimen in improving heart function.

Quinic Acid-Conjugated Nanoparticles Enhance Drug Delivery to Solid Tumors via Interactions with Endothelial Selectins

Current nanoparticle (NP) drug carriers mostly depend on the enhanced permeability and retention (EPR) effect for selective drug delivery to solid tumors. However, in the absence of a persistent EPR effect, the peritumoral endothelium can function as an access barrier to tumors and negatively affect the effectiveness of NPs. In recognition of the peritumoral endothelium as a potential barrier in drug delivery to tumors, poly(lactic-co-glycolic acid) (PLGA) NPs are modified with a quinic acid (QA) derivative, synthetic mimic of selectin ligands. QA-decorated NPs (QA-NP) interact with human umbilical vein endothelial cells expressing E-/P-selectins and induce transient increase in endothelial permeability to translocate across the layer. QA-NP reach selectin-upregulated tumors, achieving greater tumor accumulation and paclitaxel (PTX) delivery than polyethylene glycol-decorated NPs (PEG-NP). PTX-loaded QA-NP show greater anticancer efficacy than Taxol or PTX-loaded PEG-NP at the equivalent PTX dose in different animal models and dosing regimens. Repeated dosing of PTX-loaded QA-NP for two weeks results in complete tumor remission in 40-60% of MDA-MB-231 tumor-bearing mice, while those receiving control treatments succumb to death. QA-NP can exploit the interaction with selectin-expressing peritumoral endothelium and deliver anticancer drugs to tumors to a greater extent than the level currently possible with the EPR effect.

ICAM1 expression is induced by proinflammatory cytokines and associated with TLS formation in aggressive breast cancer subtypes

Intratumoral formation of tertiary lymphoid structures (TLS) within the tumor microenvironment is considered to be a consequence of antigen challenge during anti-tumor responses. Intracellular adhesion molecule 1 (ICAM1) has been implicated in a variety of immune and inflammatory responses, in addition to associate with triple negative breast cancer (TNBC). In this study, we detected TLS in the aggressive tumor phenotypes TNBC, HER2+ and luminal B, whereas the TLS negative group contained solely tumors of the luminal A subtype. We show that ICAM1 is exclusively expressed in TNBC and HER2 enriched subtypes known to be associated with inflammation and the formation of TLS. Furthermore, cell from normal mammary epithelium and breast cancer cell lines expressed ICAM1 upon stimulation with the proinflammatory cytokines TNFα, IL1β and IFNγ. ICAM1 overexpression was induced in MCF7, MDA-MB-468 and SK-BR-3 cells regardless of hormone receptor status. Taken together, our findings show that ICAM1 is expressed in aggressive subtypes of breast cancer and its expression is inducible by well-known proinflammatory cytokines. ICAM1 may be an attractive molecular target for TNBC, but further investigations elucidating the role of ICAM1 in targeted therapies have to take into consideration selective subtypes of breast cancer.

P-selectin is a nanotherapeutic delivery target in the tumor microenvironment

Disseminated tumors are poorly accessible to nanoscale drug delivery systems because of the vascular barrier, which attenuates extravasation at the tumor site. We investigated P-selectin, a molecule expressed on activated vasculature that facilitates metastasis by arresting tumor cells at the endothelium, for its potential to target metastases by arresting nanomedicines at the tumor endothelium. We found that P-selectin is expressed on cancer cells in many human tumors. To develop a targeted drug delivery platform, we used a fucosylated polysaccharide with nanomolar affinity to P-selectin. The nanoparticles targeted the tumor microenvironment to localize chemotherapeutics and a targeted MEK (mitogen-activated protein kinase kinase) inhibitor at tumor sites in both primary and metastatic models, resulting in superior antitumor efficacy. In tumors devoid of P-selectin, we found that ionizing radiation guided the nanoparticles to the disease site by inducing P-selectin expression. Radiation concomitantly produced an abscopal-like phenomenon wherein P-selectin appeared in unirradiated tumor vasculature, suggesting a potential strategy to target disparate drug classes to almost any tumor.

Role of liver ICAM-1 in metastasis

Intercellular adhesion molecule (ICAM)-1, is a transmembrane glycoprotein of the immunoglobulin (Ig)-like superfamily, consisting of five extracellular Ig-like domains, a transmembrane domain and a short cytoplasmic tail. ICAM-1 is expressed in various cell types, including endothelial cells and leukocytes, and is involved in several physiological processes. Furthermore, it has additionally been reported to be expressed in various cancer cells, including melanoma, colorectal cancer and lymphoma. The majority of studies to date have focused on the expression of the ICAM-1 on the surface of tumor cells, without research into ICAM-1 expression at sites of metastasis. Cancer cells frequently metastasize to the liver, due to its unique physiology and specialized liver sinusoid capillary network. Liver sinusoidal endothelial cells constitutively express ICAM-1, which is upregulated under inflammatory conditions. Furthermore, liver ICAM-1 may be important during the development of liver metastasis. Therefore, it is necessary to improve the understanding of the mechanisms mediated by this adhesion molecule in order to develop host-directed anticancer therapies.

New insights into the heterogeneity and functional diversity of human mesenchymal stem cells

Mesenchymal stem cells (MSCs) are being tested in several biological systems and clinical settings with the aim of exploring their therapeutic potentials for a variety of diseases. MSCs are also known to be heterogeneous populations with variable functions. In the context of this multidimensional complexity, a recurrent question is what source or population of MSCs is suitable for specific clinical indications. Here, we reported that the biological features of MSCs varied with the individual donor, the tissue source, the culture condition and the subpopulations. Placental chorionic villi (CV) derived MSCs exhibited superior activities of immunomodulation and pro-angiogenesis compared to MSCs derived from bone marrow (BM), adipose and umbilical cord (UC). We identified a subpopulation of CD106(VCAM-1)+MSCs, which are present richly in placental CV, moderately in BM, and lowly in adipose and UC. The CD106+MSCs possess significantly increased immunomodutory and pro-angiogenic activities compared to CD106-MSCs. Analysis of gene expression and cytokine secretion revealed that CD106+MSCs highly expressed several immnumodulatory and pro-angiogenic cytokines. Our data offer new insights on the identification and selection of suitable source or population of MSCs for clinical applications. Further efforts should be concentrated on standardizing methods which will ultimately allow the validation of MSC products with defined biomarkers as predictive of potency in suitable pre-clinical models and clinical settings.

Breast cancer metastasis: Putative therapeutic role of vascular cell adhesion molecule-1

BACKGROUND

Breast cancer is a notable cause of cancer-related death in women worldwide. Metastasis to distant organs is responsible for ~90% of this death. Breast cells convert to malignant cancer cells after acquiring the capacity of invasion/intravasation into surrounding tissues and, finally, extravasation/metastasis to distant organs (i.e., lymph nodes, lungs, bone, brain). Metastasis to distant organs depends on interactions between disseminated tumor cells (DTCs) and the endothelium of blood vessels present in the tumor microenvironment. Among several known endothelial adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) has been found to be involved in this process. It has been shown that VCAM-1 is aberrantly expressed in breast cancer cells and that it can bind to its natural ligand α4β1integrin, also denoted as very late antigen 4 (VLA-4). This binding appears to be responsible for the metastasis of breast cancer cells to lung, bone and brain. The α4β1 integrin - VCAM-1 interaction thus represents a potential therapeutic target for metastatic breast cancer cells. The development of inhibitors of this interaction may be instrumental for the clinical management of breast cancer patients.

CONCLUSIONS

This study focuses on recent progress on the role of VCAM-1, an important glycoprotein belonging to the immunoglobulin (Ig) superfamily of cell surface adhesion molecules in breast cancer angiogenesis, survival and metastasis. Targeting VCAM-1, expressed on the surface of breast cancer cells, and/or its specific ligand VLA-4/α4β1 integrin, expressed on cells at the site of metastasis, may be a useful strategy to reduce breast cancer cell invasion and metastasis. Various approaches to therapeutically target VCAM-1 and VLA-4 are also discussed.

β-Catenin promotes cell proliferation, migration, and invasion but induces apoptosis in renal cell carcinoma

β-Catenin (CTNNB1 gene coding protein) is a component of the Wnt signaling pathway that has been shown to play an important role in the formation of certain cancers. Abnormal accumulation of CTNNB1 contributes to most cancers. This research studied the involvement of β-catenin in renal cell carcinoma (RCC) cell proliferation, apoptosis, migration, and invasion. Proliferation, cell cycle, and apoptosis were analyzed by using Cell Counting Kit-8 and by flow cytometry. Migration and invasion assays were measured by transwell analysis. Real-time polymerase chain reaction and Western blot analysis were used to detect the expression of CTNNB1, ICAM-1, VCAM-1, CXCR4, and CCL18 in RCC cell lines. It was found that CTNNB1 knockdown inhibited cell proliferation, migration, and invasion and induced apoptosis of A-498 cells. CTNNB1 overexpression promoted cell proliferation, migration, and invasion and inhibited apoptosis of 786-O cells. Moreover, knockdown of CTNNB1 decreased the levels of ICAM-1, VCAM-1, CXCR4, and CCL18 expression, but CTNNB1 overexpression increased the expression of ICAM-1, VCAM-1, CXCR4, and CCL18. Further in vivo tumor formation study in nude mice indicated that inhibition of CTNNB1 delayed the progress of tumor formation through inhibiting PCNA and Ki67 expression. These results indicate that CTNNB1 could act as an oncogene and may serve as a promising therapeutic strategy for RCC.

Tumour-specific PI3K inhibition via nanoparticle-targeted delivery in head and neck squamous cell carcinoma

Alterations in PIK3CA, the gene encoding the p110α subunit of phosphatidylinositol 3-kinase (PI3Kα), are frequent in head and neck squamous cell carcinomas. Inhibitors of PI3Kα show promising activity in various cancer types, but their use is curtailed by dose-limiting side effects such as hyperglycaemia. In the present study, we explore the efficacy, specificity and safety of the targeted delivery of BYL719, a PI3Kα inhibitor currently in clinical development in solid tumours. By encapsulating BYL719 into P-selectin-targeted nanoparticles, we achieve specific accumulation of BYL719 in the tumour milieu. This results in tumour growth inhibition and radiosensitization despite the use of a sevenfold lower dose of BYL719 compared with oral administration. Furthermore, the nanoparticles abrogate acute and chronic metabolic side effects normally observed after BYL719 treatment. These findings offer a novel strategy that could potentially enhance the efficacy of PI3Kα inhibitors while mitigating dose-limiting toxicity in patients with head and neck squamous cell carcinomas.

Head and neck squamous cell carcinomas (HNSCC) often harbour PIK3CA mutations but PI3Kα inhibitors can cause some side effects. Here, the authors develop P-selectin targeted nanoparticles to enhance tumour-specific delivery of a PI3Kα inhibitor to HNSCC PDX and orthotopic xenograft models.

VCAM-1+ placenta chorionic villi-derived mesenchymal stem cells display potent pro-angiogenic activity

Introduction

Mesenchymal stem cells (MSCs) represent a heterogeneous cell population that is promising for regenerative medicine. The present study was designed to assess whether VCAM-1 can be used as a marker of MSC subpopulation with superior angiogenic potential.

Methods

MSCs were isolated from placenta chorionic villi (CV). The VCAM-1^+/− CV-MSCs population were separated by Flow Cytometry and subjected to a comparative analysis for their angiogenic properties including angiogenic genes expression, vasculo-angiogenic abilities on Matrigel in vitro and in vivo, angiogenic paracrine activities, cytokine array, and therapeutic angiogenesis in vascular ischemic diseases.

Results

Angiogenic genes, including HGF, ANG, IL8, IL6, VEGF-A, TGFβ, MMP₂ and bFGF, were up-regulated in VCAM-1⁺CV-MSCs. Consistently, angiogenic cytokines especially HGF, IL8, angiogenin, angiopoitin-2, μPAR, CXCL1, IL-1β, IL-1α, CSF2, CSF3, MCP-3, CTACK, and OPG were found to be significantly increased in VCAM-1⁺ CV-MSCs. Moreover, VCAM-1⁺CV-MSCs showed remarkable vasculo-angiogenic abilities by angiogenesis analysis with Matrigel in vitro and in vivo and the conditioned medium of VCAM-1⁺ CV-MSCs exerted markedly pro-proliferative and pro-migratory effects on endothelial cells compared to VCAM-1⁻CV-MSCs. Finally, transplantation of VCAM-1⁺CV-MSCs into the ischemic hind limb of BALB/c nude mice resulted in a significantly functional improvement in comparison with VCAM-1⁻CV-MSCs transplantation.

Conclusions

VCAM-1⁺CV-MSCs possessed a favorable angiogenic paracrine activity and displayed therapeutic efficacy on hindlimb ischemia. Our results suggested that VCAM-1⁺CV-MSCs may represent an important subpopulation of MSC for efficient therapeutic angiogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-016-0297-0) contains supplementary material, which is available to authorized users.

Reprogramming the tumor microenvironment: tumor-induced immunosuppressive factors paralyze T cells

It has become evident that tumor-induced immuno-suppressive factors in the tumor microenvironment play a major role in suppressing normal functions of effector T cells. These factors serve as hurdles that limit the therapeutic potential of cancer immunotherapies. This review focuses on illustrating the molecular mechanisms of immunosuppression in the tumor microenvironment, including evasion of T-cell recognition, interference with T-cell trafficking, metabolism, and functions, induction of resistance to T-cell killing, and apoptosis of T cells. A better understanding of these mechanisms may help in the development of strategies to enhance the effectiveness of cancer immunotherapies.

Tumor necrosis factor-alpha-converting enzyme activities and tumor-associated macrophages in breast cancer

The role of the tumor microenvironment especially of tumor-associated macrophages (TAMs) in the progression and metastatic spread of breast cancer is well established. TAMs have primarily a M2 (wound-healing) phenotype with minimal cytotoxic activities. The mechanisms by which tumor cells influence TAMs to display a pro-tumor phenotype are still debated although the key roles of immunomodulatory cytokines released by tumor cells, including colony-stimulating factor 1, tumor necrosis factor (TNF) and soluble TNF receptors 1/2, soluble vascular cell adhesion molecule 1, soluble interleukin 6 receptor and amphiregulin, have been demonstrated. Importantly, these factors are released through ectodomain shedding by the activities of the tumor necrosis factor-alpha-converting enzyme (TACE/ADAM17). The role of TACE activation leading to autocrine effects on tumor progression has been extensively studied. In contrast, limited information is available on the role of tumor cell TACE activities on TAMs in breast cancer. TACE inhibitors, currently in clinical trials, will certainly affect TAMs and subsequently treatment outcomes based on the substrates it releases. Furthermore, whether targeting a subset of the molecules shed by TACE, specifically those leading to TAMs with altered functions and phenotype, holds greater therapeutic promises than past clinical trials of TACE antagonists' remains to be determined. Here, the potential roles of TACE ectodomain shedding in the breast tumor microenvironment are reviewed with a focus on the release of tumor-derived immunomodulatory factors shed by TACE that directs TAM phenotypes and functions.

Activation of VCAM-1 and its associated molecule CD44 leads to increased malignant potential of breast cancer cells

VCAM-1 (CD106), a transmembrane glycoprotein, was first reported to play an important role in leukocyte adhesion, leukocyte transendothelial migration and cell activation by binding to integrin VLA-1 (α4β1). In the present study, we observed that VCAM-1 expression can be induced in many breast cancer epithelial cells by cytokine stimulation in vitro and its up-regulation directly correlated with advanced clinical breast cancer stage. We found that VCAM-1 over-expression in the NMuMG breast epithelial cells controls the epithelial and mesenchymal transition (EMT) program to increase cell motility rates and promote chemoresistance to doxorubicin and cisplatin in vitro. Conversely, in the established MDAMB231 metastatic breast cancer cell line, we confirmed that knockdown of endogenous VCAM-1 expression reduced cell proliferation and inhibited TGFβ1 or IL-6 mediated cell migration, and increased chemosensitivity. Furthermore, we demonstrated that knockdown of endogenous VCAM-1 expression in MDAMB231 cells reduced tumor formation in a SCID xenograft mouse model. Signaling studies showed that VCAM-1 physically associates with CD44 and enhances CD44 and ABCG2 expression. Our findings uncover the possible mechanism of VCAM-1 activation facilitating breast cancer progression, and suggest that targeting VCAM-1 is an attractive strategy for therapeutic intervention.

Emerging role of tumor-associated macrophages as therapeutic targets in patients with metastatic renal cell carcinoma

Tumor-associated macrophages (TAMs) derived from peripheral blood monocytes recruited into the renal cell carcinoma (RCC) microenvironment. In response to inflammatory stimuli, macrophages undergo M1 (classical) or M2 (alternative) activation. M1 cells produce high levels of inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-12, IL-23 and IL-6, while M2 cells produce anti-inflammatory cytokines, such as IL-10, thus contributing to RCC-related immune dysfunction. The presence of extensive TAM infiltration in RCC microenvironment contributes to cancer progression and metastasis by stimulating angiogenesis, tumor growth, and cellular migration and invasion. Moreover, TAMs are involved in epithelial-mesenchymal transition of RCC cancer cells and in the development of tumor resistance to targeted agents. Interestingly, macrophage autophagy seems to play an important role in RCC. Based on this scenario, TAMs represent a promising and effective target for cancer therapy in RCC. Several strategies have been proposed to suppress TAM recruitment, to deplete their number, to switch M2 TAMs into antitumor M1 phenotype and to inhibit TAM-associated molecules. In this review, we summarize current data on the essential role of TAMs in RCC angiogenesis, invasion, impaired anti-tumor immune response and development of drug resistance, thus describing the emerging TAM-centered therapies for RCC patients.

Role of natural and adaptive immunity in renal cell carcinoma response to VEGFR-TKIs and mTOR inhibitor

Angiogenesis and immunosuppression work hand-in-hand in the renal cell carcinoma (RCC) microenvironment. Tumor growth is associated with impaired antitumor immune response in RCC, which involves T cells, natural killer cells, dendritic cells (DCs) and macrophages. Vascular endothelial growth factor receptor (VEGFR), such as sorafenib, sunitinib, pazopanib and axitinib, and mammalian target of rapamycin (mTOR) inhibitors, such as temsirolimus and everolimus, do exert both antiangiogenic and immunomodulatory functions. Indeed, these agents affect neutrophil migration, as well as T lymphocyte-DC cross-talk, DC maturation and immune cell metabolism and reactivity. In this review, we overview the essential role of innate and adaptive immune response in RCC proliferation, invasion and metastasis and the relationship between tumor-associated immune cells and the response to targeted agents approved for the treatment of metastatic RCC.

Regulation of self-ligands for activating natural killer cell receptors

Natural killer (NK) cells are able to lyse infected and tumor cells while sparing healthy cells. Recognition of diseased cells by NK cells is governed by several activating and inhibitory receptors. We review numerous pathways that have been implicated in the regulation of self-ligands for activating receptors, including NKG2D, DNAM-1, LFA-1, NKp30, NKp44, NKp46, NKp65, and NKp80 found on NK cells and some T cells. Understanding how the regulation of self-encoded ligand expression is regulated may provide novel avenues for future therapeutic approaches to infections and cancer.

Antibody drug-conjugates targeting the tumor vasculature: Current and future developments

Reducing the blood supply of tumors is one modality to combat cancer. Monoclonal antibodies are now established as a key therapeutic approach for a range of diseases. Owing to the ability of antibodies to selectively target endothelial cells within the tumor vasculature, vascular targeting programs have become a mainstay in oncology drug development. However, the antitumor activity of single agent administration of conventional anti-angiogenic compounds is limited and the improvements in patient survival are most prominent in combinations with chemotherapy. Furthermore, prolonged treatment with conventional anti-angiogenic drugs is associated with toxicity and drug resistance. These circumstances provide a strong rationale for novel approaches to enhance the efficacy of mAbs targeting tumor vasculature such as antibody-drug conjugates (ADCs).Here, we review trends in the development of ADCs targeting tumor vasculature with the aim of informing future research and development of this class of therapeutics.

Pathogenic angiogenesis in IBD and experimental colitis: new ideas and therapeutic avenues

Angiogenesis is now understood to play a major role in the pathology of chronic inflammatory diseases and is indicated to exacerbate disease pathology. Recent evidence shows that angiogenesis is crucial during inflammatory bowel disease (IBD) and in experimental models of colitis. Examination of the relationship between angiogenesis and inflammation in experimental colitis shows that initiating factors for these responses simultaneously increase as disease progresses and correlate in magnitude. Recent studies show that inhibition of the inflammatory response attenuates angiogenesis to a similar degree and, importantly, that inhibition of angiogenesis does the same to inflammation. Recent data provide evidence that differential regulation of the angiogenic mediators involved in IBD-associated chronic inflammation is the root of this pathological angiogenesis. Many factors are involved in this phenomenon, including growth factors/cytokines, chemokines, adhesion molecules, integrins, matrix-associated molecules, and signaling targets. These factors are produced by various vascular, inflammatory, and immune cell types that are involved in IBD pathology. Moreover, recent studies provide evidence that antiangiogenic therapy is a novel and effective approach for IBD treatment. Here we review the role of pathological angiogenesis during IBD and experimental colitis and discuss the therapeutic avenues this recent knowledge has revealed.

Vascular Cell Adhesion Molecule 1 Predicts Cancer-Free Survival in Clear Cell Renal Carcinoma Patients

PURPOSE

Vascular cell adhesion molecule 1 (VCAM1) is a cell surface glycoprotein implicated in various pathophysiologic conditions. We measured VCAM1 expression levels in tumor tissues and evaluated its significance and prognostic use in renal cell carcinoma (RCC).

EXPERIMENTAL DESIGN

We used real-time quantitative PCR to examine the VCAM1 expression levels of a total of 485 sporadic renal tumors, including 429 clear cell, 21 papillary, 17 chromophobe, 11 oncocytomas, and 7 collecting duct carcinomas. We retrospectively examined the relationship of this expression to various clinicopathologic variables and the von Hippel-Lindau alteration status. We evaluated its significance with respect to patient survival rates using the Cox regression model combined with the split-sample method.

RESULTS

Compared with normal kidney samples (n = 43), VCAM1 was significantly up-regulated in clear cell RCC and papillary RCC, whereas it was down-regulated in chromophobe RCC and oncocytoma. In clear cell RCC, VCAM1 expression levels were apparently high in patients asymptomatic at presentation and in patients with small tumor size, low-stage, low-grade, microvascular invasion-negative, and von Hippel-Lindau alteration-positive tumors. Univariate analyses showed that VCAM1 high expression is strongly associated with better outcomes in clear cell and papillary RCCs. Further, Cox multivariate analysis models combined with the split-sample method revealed that this association is significant only in cancer-free survival for patients with clear cell RCC after curative surgical resection.

CONCLUSIONS

VCAM1 expression levels were found to be histologically subtype specific in renal tumors. Determination of the VCAM1 expression level as a biomarker can provide useful prognostic information for patients with clear cell RCC.

Characterization of macrophage subpopulations in colon cancer using tissue microarrays

AIMS

To determine the pattern of macrophage infiltration in colon cancers and its correlation with clinicopathological characteristics.

METHODS AND RESULTS

Colon cancers from 100 patients were arrayed into a tissue microarray (TMA). Four cores per tumour were taken: three from the invasion front (IF) and one from the tumour surface (TS). Macrophages were quantified by immunohistochemistry with antibodies to the PG-M1, KP-1, MRP8, MRP14 and MRP8/14 antigens. The number of macrophages was significantly higher in the TS cores than in the IF cores and both tumour sites showed a higher number of macrophages than the normal mucosa. The number of macrophages decreased in higher stage tumours. The different tumour-associated macrophage (TAM) subpopulations were positively correlated with each other.

CONCLUSIONS

The increased number of macrophages in cancers compared with normal colon mucosa indicates that macrophages are attracted to the tumour site. However, decreasing macrophages in higher stage colon cancers suggest that this attraction decreases with tumour progression.

Specific Occlusion of Murine and Human Tumor Vasculature by VCAM-1–Targeted Recombinant Fusion Proteins

BACKGROUND

The tumor vasculature is increasingly recognized as a target for cancer therapy. We developed and evaluated recombinant fusion proteins targeting the coagulation-inducing protein soluble tissue factor (sTF) to the luminal tumor endothelial antigen vascular cell adhesion molecule 1 (VCAM-1, CD106).

METHODS

We generated fusion proteins consisting of sTF fused to antibody fragments directed against mouse or human VCAM-1 and characterized them in vitro by flow cytometry, surface plasmon resonance, and two-stage coagulation assays. Their therapeutic effects were tested in three human xenograft tumor models: L540rec Hodgkin lymphoma, Colo677 small-cell lung carcinoma, and Colo677/HDMEC small-cell lung carcinoma with human vasculature. Toxicity was analyzed by histologic examination of organs and determination of laboratory blood parameters.

RESULTS

The fusion proteins bound VCAM-1 with nanomolar affinities and had the same coagulation activity as an sTF standard. Xenograft tumor-bearing mice treated with fusion protein (FP) alone or in combination with lipopolysaccharide (FP/L) or doxorubicin (FP/D) exhibited tumor-selective necrosis (L540rec tumors: 74% tumor necrosis [95% confidence interval {CI} = 55% to 93%] with FP/L versus 13% tumor necrosis [95% CI = 4% to 22%] with vehicle; Colo677 tumors: 26% [95% CI = 16% to 36%] with FP versus 8% [95% CI = 2% to 14%] with vehicle); tumor growth delay (Colo677/HDMEC: mean tumor weights after 3 days = 42 mg in FP-treated mice versus 71 mg in vehicle-treated mice, difference = 29 mg, 95% CI = 8 to 100, Mann-Whitney P = .008); and some tumor regressions (one of seven FP-treated Colo677 tumor-bearing mice and two of seven FP/D-treated mice). The fusion protein was well tolerated.

CONCLUSIONS

Recombinant tissue factor-based fusion proteins directed against an intraluminal tumor endothelial cell marker induce tumor-selective intravascular coagulation, tumor tissue necrosis, and tumor growth delay.

Estimation of concentration of chosen adhesive factors in suprarenal tumours of 'incidentaloma' type

The role of adhesive molecules in the pathogenesis of adrenal gland tumours formation remains unclear. Here we present the concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intracellular adhesion molecule-1 (sICAM-1) in the blood of patients with adrenal "incidentaloma". We found that the mean concentrations of sVCAM and sICAM in the serum of the patients with adrenocortical cancers were significantly higher than those of the patients with benign adenomas or control cases. These results suggest that the levels of adhesion molecules may be a marker of malignancy of adrenal incidentalomas.

Association of VCAM-1 overexpression with oncogenesis, tumor angiogenesis and metastasis of gastric carcinoma

AIM: To investigate the relationship between the expression of vascular cell adhesion molecule-1 (VCAM-1) and oncogenesis, tumor angiogenesis and metastasis in gastric carcinoma, and to evaluate the clinical significance of serum VCAM-1 levels in gastric cancer.

METHODS: Specimens from 41 patients with gastric cancer, 8 patients with benign gastric ulcer, and 10 healthy subjects were detected for the expression of VCAM-1 by immunohistochemistry. Microvessel density (MVD) was measured by counting the endothelial cells immunostained with the monoclonal antibody CD34 at × 200 magnification. Serum VCAM-1 concentrations were measured by an enzyme linked immunosorbent assay in the 41 gastric cancer patients before surgery, and at 7 d after surgery as well as in 25 healthy controls. The association between preoperative serum VCAM-1 levels and clinicopathological features, and their changes following surgery was evaluated. In addition, serum carcinoembryonic antigen (CEA) was also examined.

RESULTS: Of the 41 gastric cancer tissues, 31 (75.6%) were VCAM-1 positive. The VCAM-1 positive gastric cancers were more invasive and classified in the more advanced stage than the VCAM-1 negative ones. The VCAM-1 positive cancers were associated with more lymph node metastases than VCAM-1-negative ones (P < 0.05). The expression of VCAM-1 was detected in tissues of two of the eight patients with gastric ulcer and two of the 10 healthy controls. The expression of VCAM-1 in gastric cancer patients was significantly more frequent than that in the healthy controls and ulcer group (both P < 0.05). MVD in VCAM-1 expressing tissues was higher than that in VCAM-1 negative tissues (t = 2.13, P < 0.05). Serum VCAM-1 levels in gastric cancer patients were significantly higher than those in controls (t = 3.4, P < 0.05). There was a significant association between serum VCAM-1 levels and disease stage, as well as invasion depth of the tumor and the presence of distant metastases. The concentrations of serum CEA in gastric cancer were higher than normal controls. Both serum VCAM-1 and CEA levels decreased significantly after radical resection of the primary tumor (P < 0.05). Furthermore, the serum levels of VCAM-1 were positively correlated with the expression of VCAM-1 in the tumor tissue (r = 0.85, P < 0.05).

CONCLUSION: The expression of VCAM-1 is closely related to oncogenesis, tumor angiogenesis and metastasis in gastric carcinoma. Serum VCAM-1 level in gastric cancer patients is significantly increased compared with normal controls, which decreases significantly after radical resection of the primary tumor. The serum concentration of VCAM-1 may be considered as an effective marker of tumor burden of gastric cancer. Moreover, overexpression of VCAM-1 in gastric cancer tissue is likely a major source of serum VCAM-1.

Novel expression of vascular cell adhesion molecule-1 (CD106) by squamous epithelium in experimental acute graft-versus-host disease

Vascular cell adhesion molecule-1 (VCAM-1; CD106), the receptor for VLA-4, is an important mediator of adhesive and co-stimulatory interactions that govern cutaneous immune responses. Initial studies designed to elucidate temporal aspects of endothelial adhesion molecule induction in murine acute graft-versus-host disease (aGVHD) revealed unexpected and novel VCAM-1 expression by cutaneous and mucosal epithelial cells. Immunohistochemical techniques confirmed VCAM-1 staining as early as 7 days after transplantation in a distinctive subpopulation of squamous epithelial cells that normally occupy focal domains within the epidermal basal cell layer, the follicular infundibulum, and the dorsal lingual epithelium. Specifically, VCAM-1 expression was intimately associated with rete ridge-like prominences in footpad epidermis and in dorsal lingual epithelium. VCAM-1, as evaluated by serial section-labeling techniques, was preferentially expressed at sites of early epithelial infiltration by CD4(+) T cells. Western blot analysis confirmed expression of the 110-kd isoform of VCAM-1 in epithelium isolated from aGVHD animals, and immunoelectron microscopy demonstrated VCAM-1 reactivity restricted exclusively to epithelial cell plasma membranes. It is concluded that VCAM-1 is selectively expressed by discrete squamous epithelial subpopulations in murine aGVHD. As such, VCAM-1 may play a previously unrecognized role in mediating interactions between donor effector T lymphocytes and host epithelial cell targets.

Adhesion molecules in human pancreatic cancer

BACKGROUND AND OBJECTIVES

Adhesion molecules are cell surface glycoproteins that are important in cell-to-cell and cell-to-extracellular matrix interactions. In the present study, we analyzed the adhesion molecules ICAM-1 (intercellular adhesion molecule-1), VCAM-1 (vascular cell adhesion molecule-1), and ELAM-1 (endothelial leukocyte adhesion molecule-1) in human pancreatic cancer.

METHODS

ICAM-1, VCAM-1, and ELAM-1 were analyzed in 20 pancreatic cancer specimens and 20 normal pancreatic tissues. mRNA expression encoding ICAM-, VCAM-1, and ELAM-1 was assessed with Northern blot analysis. The distribution and localization of ICAM-1, VCAM-1, and ELAM-1 was determined in the pancreatic specimens by immunohistochemistry.

RESULTS

Northern blot analysis revealed a 5.4-fold increase of ICAM-1 (P<0.01) and a 3.7-fold increase in VCAM-1 (P<0.01) mRNA expression in cancer samples in comparison with normal controls. In contrast, ELAM-1 mRNA levels did not show significant differences between the cancer and the normal tissues. Immunohistochemical analysis of cancer tissues showed strong immunostaining for ICAM-1 and VCAM-1, and faint immunostaining for ELAM-1 in the pancreatic cancer cells. Fibrotic or noncancerous pancreatic tissue adjacent to the cancer mass was devoid of any immunoreactivity for ICAM-1, ELAM-1, and VCAM-1. In contrast, the normal pancreas exhibited no immunoreactivity of ICAM-1, ELAM-1, and VCAM-1.

CONCLUSIONS

Enhanced expression of ICAM-1 and VCAM-1 in human pancreatic cancers suggests a role in tumor pathogenesis. The increase of these adhesion molecules might influence the detachment of cancer cells in the primary tumor, might contribute to cancer cell migration and the spread of cancer cells to distant organs, or both.

Expression of cell adhesion molecules, their ligands and tumour necrosis factor alpha in the liver of patients with metastatic gastrointestinal carcinomas

The expression of the following cell adhesion molecules, their beta1 and beta2 integrin ligands and the cytokine tumour necrosis factor-alpha (TNF-alpha) was investigated by light and electron microscope immunohistochemistry in the liver tissue in 20 patients with colorectal and gastric cancer also presenting with liver metastases: intercellular adhesion molecule-1 (ICAM-1), vascular endothelial adhesion molecule-1 (VCAM-1), E-selectin, leucocyte function-associated antigen-1 (LFA-1), macrophage antigen-1 (Mac-1), and very late antigen-4 (VLA-4). We have found a parallel enhancement of the adhesion molecules and of TNF-alpha in liver sinusoids surrounding metastases. The expression of ICAM-1 was enhanced on sinusoidal cells in all zones of the acinus. VCAM-1 immune reactivity was diffuse but less intensive in the lobule. E-selectin expression was observed in sinusoidal cells attached to metastases. In tumour metastases the expression of ICAM-1, VCAM-1, and E-selectin was visible on the tumour vascular endothelium. Tumour infiltrating host cells sowing positive immunoreactivity for ICAM-1, VCAM-1, LFA-1, Mac-1, and VLA-4 were located mainly at the boundary between liver parenchyma and the metastasis. At the ultrastructural level, ICAM-1-positive immune deposits were observed on the cellular membrane and in some transport vesicles of gastric metastatic cells. Further, the expression of all adhesion molecules was confirmed to sinusoidal endothelial cells and tumour vessels. It is concluded that the enhanced expression of adhesion molecules in liver sinusoids could be a marker for the assessment of the ability of sinusoidal endothelial cells to control the recruitment of leukocytes and monocytes to the metastatic site. They could also direct the adhesion of new circulating tumour cells to sinusoidal endothelium.

Quantification and in situ localization of MCP-1 mRNA and its relation to the immune response of renal cell carcinoma

Malignant tumours are usually accompanied by an immune response. Chemokines such as MCP-1 have been claimed to be potent inducers of such tumour-associated reactions. In the present study MCP-1 mRNA was quantified by competitive reverse transcription polymerase reaction and localised by in situ hybridisation in renal cell carcinoma tissue in comparison to tumour-free tissue of the same nephrectomy specimen. MCP-1 mRNA levels were correlated with the immune cell infiltrate, the density of CD31(+)microvessels, and the endothelial expression of ICAM-1, VCAM-1, E-, and P-selectin. In only seven of 19 cases, MCP-1 mRNA levels in carcinoma tissue were increased in comparison to tumour-free tissue. Within tumour tissue, mRNA transcripts could be localised in tumour cells, microvessel endothelia, and in tumour-associated macrophages. A correlation between MCP-1 mRNA levels and the density of immune cells, especially macrophages, the microvessel density, and the expression of adhesion molecules could not be observed. Therefore, MCP-1 seems to be of minor importance for the induction of an immune response in renal cell carcinomas regarding at least the parameters analysed in this study.