Elevated expression of integrin αv and β5 subunit in laryngeal squamous-cell carcinoma associated with lymphatic metastasis and angiogenesis

Diagnostic, Prognostic, and Therapeutic Role for Angiogenesis Markers in Head and Neck Squamous Cell Carcinoma: A Narrative Review

Despite refinements to diagnostic and therapeutic approaches over the last two decades, the outcome of patients with head and neck squamous cell carcinoma (HNSCC) has not shown substantial improvements, especially regarding those with advanced-stage disease. Angiogenesis is believed to be a turning point in the development of solid tumors, being a premise for mass growth and potential distant dissemination. Cancer-induced angiogenesis is a result of increased expression of angiogenic factors, decreased expression of anti-angiogenic factors, or a combination of both. The assessment of angiogenesis has also emerged as a potentially useful biological prognostic and predictive factor in HNSCC. The aim of this review is to assess the level of current knowledge on the neo-angiogenesis markers involved in the biology, behavior, and prognosis of HNSCC. A search (between 1 January 2012 and 10 October 2022) was run in PubMed, Scopus, and Web of Science electronic databases. After full-text screening and application of inclusion/exclusion criteria, 84 articles are included. The current knowledge and debate on angiogenesis in HNSCC presented in the eligible articles are stratified as follows: (i) diagnostic markers; (ii) prognostic markers; (iii) predictive markers; and (iv) markers with a potential therapeutic role. Angiogenesis is a biological and pathological indicator of malignancies progression and has negative implications in prognosis of some solid tumors; several signals capable of tripping the "angiogenic switch" have also been identified in HNSCC. Although several studies suggested that antiangiogenic agents might be a valuable adjunct to conventional chemo-radiation of HNSCC, their long-term therapeutic value remains uncertain. Further investigations are required on combinations of antiangiogenic agents with conventional chemotherapeutic ones, immunotherapeutic and molecularly targeted agents in HNSCC. Additional data are necessary to pinpoint which patients could benefit most from these treatments.

Epithelial-to-Mesenchymal Transition in Metastasis: Focus on Laryngeal Carcinoma

In epithelial neoplasms, such as laryngeal carcinoma, the survival indexes deteriorate abruptly when the tumor becomes metastatic. A molecular phenomenon that normally appears during embryogenesis, epithelial-to-mesenchymal transition (EMT), is reactivated at the initial stage of metastasis when tumor cells invade the adjacent stroma. The hallmarks of this phenomenon are the abolishment of the epithelial and acquisition of mesenchymal traits by tumor cells which enhance their migratory capacity. EMT signaling is mediated by complex molecular pathways that regulate the expression of crucial molecules contributing to the tumor’s metastatic potential. Effectors of EMT include loss of adhesion, cytoskeleton remodeling, evasion of apoptosis and immune surveillance, upregulation of metalloproteinases, neovascularization, acquisition of stem-cell properties, and the activation of tumor stroma. However, the current approach to EMT involves a holistic model that incorporates the acquisition of potentials beyond mesenchymal transition. As EMT is inevitably associated with a reverse mesenchymal-to-epithelial transition (MET), a model of partial EMT is currently accepted, signifying the cell plasticity associated with invasion and metastasis. In this review, we identify the cumulative evidence which suggests that various aspects of EMT theory apply to laryngeal carcinoma, a tumor of significant morbidity and mortality, introducing novel molecular targets with prognostic and therapeutic potential.

RGDX1 X2 motif regulates integrin αvβ5 binding for pluripotent stem cell adhesion

The arginine-glycine-aspartic acid (RGD) motif is a cell adhesion sequence that binds to integrins. Some RGD-containing peptides promote adhesion of both embryonic stem cells and induced pluripotent stem cells (iPSCs); however, not all such RGD-containing peptides are active. In this study, we elucidated the role of RGD-neighboring sequences on iPSC adhesion using diverse synthetic peptides and recombinant proteins. Our results indicate that iPSC adhesion requires RGDX₁ X₂  sequences, such as RGDVF and RGDNY, and that the X₁ X₂ residues are essential for the adhesion via integrin αvβ5 but not αvβ3. iPSCs express integrin αvβ5 but not αvβ3; therefore, iPSC adhesion requires the RGDX₁ X₂ -containing sequences. The importance of the X₁ X₂ residues was confirmed with both HeLa and A549 cells, which express integrin αvβ5 but not αvβ3. Analysis of RGD-neighboring sequences provides important insights into ligand-binding specificity of integrins. Identification of integrin αvβ5-binding motifs is potentially useful in drug development, drug delivery, cell culture, and tissue engineering.

High-Risk Human Papillomavirus and Epstein-Barr Virus Coinfection: A Potential Role in Head and Neck Carcinogenesis

Simple Summary

A subset of carcinomas that arise in the head and neck region show a viral etiology. In fact, a subgroup of oropharyngeal cancers are caused by some types of human papillomavirus (HPV), so-called high-risk (HR)-HPVs, whereas undifferentiated nasopharyngeal carcinomas are etiologically related to Epstein–Barr virus (EBV). However, studies have reported the presence of both HR-HPV and EBV in some types of head and neck cancers. In this review, we discuss the potential contribution and role of HR-HPV/EBV coinfection in head and neck carcinogenesis, as well as the mechanisms that are potentially involved. In addition, HR-HPV/EBV interaction models are proposed.

Abstract

High-risk human papillomaviruses (HR-HPVs) and Epstein–Barr virus (EBV) are recognized oncogenic viruses involved in the development of a subset of head and neck cancers (HNCs). HR-HPVs are etiologically associated with a subset of oropharyngeal carcinomas (OPCs), whereas EBV is a recognized etiological agent of undifferentiated nasopharyngeal carcinomas (NPCs). In this review, we address epidemiological and mechanistic evidence regarding a potential cooperation between HR-HPV and EBV for HNC development. Considering that: (1) both HR-HPV and EBV infections require cofactors for carcinogenesis; and (2) both oropharyngeal and oral epithelium can be directly exposed to carcinogens, such as alcohol or tobacco smoke, we hypothesize possible interaction mechanisms. The epidemiological and experimental evidence suggests that HR-HPV/EBV cooperation for developing a subset of HNCs is plausible and warrants further investigation.

RNF185-AS1 promotes hepatocellular carcinoma progression through targeting miR-221-5p/integrin β5 axis

AIMS

Recently, long noncoding RNAs (lncRNAs) have been reported to play important role in the pathogenesis of various cancers. However, the functions of RNF185-AS1 in hepatocellular carcinoma (HCC) remain unknown.

MATERIALS AND METHODS

The RNF185-AS1 expression in HCC cells and tissues was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The effects of RNF185-AS1 on tumor cell proliferation, migration and invasion were assessed by Cell Counting Kit-8 (CCK8) assay, colony formation assay, transwell assay. The luciferase reporter assay, RNA-binding protein immunoprecipitation assay, qRT-PCR and Western blot were performed to explore and confirm the interaction between RNF185-AS1 and miR-221-5p and integrin β5. The role of RNF185-AS1 in tumor progression was explored through in vivo experiments.

KEY FINDINGS

RNF185-AS1 was highly expressed in HCC tissues and cell lines. High levels of RNF185-AS1 were correlated with advanced TNM stage, distant metastasis and a poorer overall survival rate. RNF185-AS1 knockdown inhibited cell proliferation, migration and invasion. Additionally, RNF185-AS1 acted as a sponge for miR-221-5p and integrin β5 was identified as a target gene of miR-221-5p. Rescue assays showed that miR-221-5p inhibitor or integrin β5 overexpression rescued the function of RNF185-AS1 knockdown on cell proliferation, migration, and invasion. Moreover, we found that RNF185-AS1 knockdown inhibited tumor growth and metastasis.

SIGNIFICANCE

Our study demonstrates that RNF185-AS1 is a new oncogenic lncRNA in HCC and suggests that the RNF185-AS1/miR-221-5p/integrin β5 axis might be a potential therapeutic target for HCC.

Selective Targeting of αvβ5 Integrin in HepG2 Cell Line by RGDechi15D Peptide

Recently, the research community has become increasingly concerned with the receptor αvβ5, a member of the well-known integrin family. Different ongoing studies have evidenced that αvβ5 integrin regulates not only physiological processes but also a wide array of pathological events, suggesting the receptor as a valuable biomarker to specifically target for therapeutic/diagnostic purposes. Remarkably, in some tumors the involvement of the receptor in cell proliferation, tumor dissemination and angiogenesis is well-documented. In this scenario, the availability of a selective αvβ5 antagonist without ‘off-target’ protein effects may improve survival rate in patients with highly aggressive tumors, such as hepatocellular carcinoma. We recently reported a cyclic peptide, RGDechi15D, obtained by structure-activity studies. To our knowledge it represents the first peptide-based molecule reported in the literature able to specifically bind αvβ5 integrin and not cross react with αvβ3. Here we demonstrated the ability of the peptide to diminish both adhesion and invasion of HepG2 cells, an in vitro model system for hepatocellular carcinoma, to reduce the cell proliferation through an apoptotic process, and to interfere with the PI3K pathway. The peptide, also decreases the formation of new vessels in endothelial cells. Taken together these results indicate that the peptide can be considered a promising molecule with properties suited to be assessed in the future for its validation as a selective therapeutic/diagnostic weapon in hepatocarcinoma.

Identification and analysis of dysregulated lncRNA and associated ceRNA in the pathogenesis of keloid

Background

Keloid is an excessive fibrosis disease caused by the abnormal proliferation of collagen fibers following trauma. Previous studies have shown that genetic factors have been considered to play important roles in keloid formation. This study is aimed to investigate the regulatory network of messenger RNAs (mRNAs) microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) in keloid, and identifying its key biomarkers.

Methods

We performed RNA-seq and miRNA-seq on keloid and normal skin samples. Sequencing datasets were analyzed by bioinformatics. Gene ontology (GO) and pathway analysis presented the characteristics of associated protein-coding genes. Differentially expressed ceRNAs were validated by quantitative reverse transcriptase-PCR (qRT-PCR).

Results

We identified a total of 319 lncRNAs, 1,533 mRNAs and 40 miRNAs as keloid-specific RNAs. Both the GO biological processes and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were analyzed for 1,219 specific genes with differentially expressed mRNAs. Then, with 509 key lncRNAs, 25 miRNAs, and 94 mRNAs, we constructed a ceRNA network and explored any potential underlying mechanisms. In the regulation of the actin cytokeleton pathway, we validated 2 pairs of ceRNAs EGFR/miR-370-3p/lnc-GLB1L-1 and ITGB5/ miR-204/ lnc-CASP9-3 in another sample size in keloid.

Conclusions

Through RNA-seq and miRNA-seq, we identified keloid-associated lncRNAs, mRNAs and miRNAs, which can be used as potential therapeutic targets and biomarkers for keloid. Our study may lay a foundation for future pathogenesis studies.

Quantitative and qualitative analysis of integrin subtype expression in melanocytes and melanoma cells

Objectives: Changes in the integrin expression pattern have been associated with the malignant transformation of melanocytes suggesting that integrins may be potential biomarkers as well as molecular targets for individualized therapy. Since there is a lack of comprehensive qualitative and quantitative expression data, we characterized the integrin expression profile in normal and malignant human cells of the melanocytic lineage.Methods: Seven melanoma cell lines as well as normal human melanocytes were investigated in western blots including recombinant integrin subunits for quantification.Results: Expression patterns were heterogeneous. In melanoma, overexpression of α4, α6, αL, β5, and β6 was found. Integrins α7, α9, and β4 were overexpressed in a subset of the melanoma cell lines. Overexpression was defined as a lack of expression in melanocytes but expression in more than half (4) of the melanoma lines. 1.9 to 6.7 × 10⁶ integrin molecules (about 0.3% of total cellular protein) were estimated to be expressed per cell. Expression of integrin αE at the protein level was found in melanoma and melanocytes, to the best of our knowledge, for the first time. Integrins αM and β2 were not detected.Conclusion: Integrins α4, α6, αL, β5, and β6 appear to be overexpressed in melanoma cells. These subunits may serve as biomarkers and/or therapeutic targets.

Selectin Binding Sites Are Involved in Cell Adhesive Properties of Head and Neck Squamous Cell Carcinoma

The formation of distant metastases often determines the fate of patients with head and neck squamous cell carcinoma (HNSCC). The expression of cell adhesion molecules (CAMs) and their ligands of the leukocyte adhesion cascade has been associated with metastatic competence in several malignant entities. In this study, human HNSCC cell lines were analyzed in vitro and in a spontaneous metastatic xenograft model. Immunohistochemical analyses of several CAMs were performed on xenograft tumors and tissue microarrays (TMA) from 453 patients with head and neck squamous cell carcinomas with full histo-pathological and clinical follow-up data. UTSCC 24A and 24B cells bind to E-selectin in vitro, show E-selectin dependent binding to human umbilical vein endothelial cells (HUVECs), and express sLeX. All HNSCC cells engrafted into severe combined immunodeficient (SCID) mice, and UTSCC 24A cells formed sporadically spontaneous lung metastases. The expression of CAMs varied between the cell lines, but a correlation between tumor growth and metastatic potential did not exist. None of the CAMS or their ligands could be identified to be of prognostic relevance in the TMA study. The in vitro results indicate that E-selectin and sLeX are involved in the adhesion of HNSCC cells to endothelium. However, specific prognostic markers chosen from the leukocyte adhesion cascade for HNSCC were not identified.

The Anti-tumor Activity and Mechanisms of rLj-RGD3 on Human Laryngeal Squamous Carcinoma Hep2 Cells

BACKGROUND

Laryngeal Squamous Cell Carcinoma (LSCC) is a malignant epithelial tumor with poor prognosis and its incidence rate increased recently. rLj-RGD3, a recombinant protein cloned from the buccal gland of Lampetra japonica, contains three RGD motifs that could bind to integrins on the tumor cells.

METHODS

MTT assay was used to detect the inhibitory rate of viability. Giemsa's staining assay was used to observe the morphological changes of cells. Hoechst 33258 and TUNEL staining assay, DNA ladder assay were used to examine the apoptotic. Western blot assay was applied to detect the change of the integrin signal pathway. Wound-healing assay, migration, and invasion assay were used to detect the mobility of Hep2 cells. H&E staining assay was used to show the arrangement of the Hep2 cells in the solid tumor tissues.

RESULTS

In the present study, rLj-RGD3 was shown to inhibit the viability of LSCC Hep2 cells in vitro by inducing apoptosis with an IC50 of 1.23µM. Western blot showed that the apoptosis of Hep2 cells induced by rLj- RGD3 was dependent on the integrin-FAK-Akt pathway. Wound healing, transwells, and western blot assays in vitro showed that rLj-RGD3 suppressed the migration and invasion of Hep2 cells by integrin-FAKpaxillin/ PLC pathway which could also affect the cytoskeleton arrangement in Hep2 cells. In in vivo studies, rLj-RGD3 inhibited the growth, tumor volume, and weight, as well as disturbed the tissue structure of the solid tumors in xenograft models of BALB/c nude mice without reducing their body weights.

CONCLUSION

These results suggested that rLj-RGD3 is an effective and safe suppressor on the growth and metastasis of LSCC Hep2 cells from both in vitro and in vivo experiments. rLj-RGD3 might be expected to become a novel anti-tumor drug to treat LSCC patients in the near future.

Integrated miRNA and mRNA expression analysis uncovers drug targets in laryngeal squamous cell carcinoma patients

OBJECTIVES

The current treatment of laryngeal squamous cell carcinoma (LSCC) is based on radical surgery and radiotherapy resulting in high morbidity. Chemoradiotherapy has been used as alternative to organ sparing; however, several advanced cases presented resistance to treatment, which contributes to a high risk of recurrence and mortality. Coding RNAs and miRNAs have potential to be used as biomarkers or targets for cancer therapy.

MATERIALS AND METHODS

In this study, 36 LSCC and 5 non-neoplastic control samples were investigated using miRNA and mRNA large-scale expression analysis and a cross-validation was performed using the TCGA database (116 LSCC and 12 surrounding normal tissues).

RESULTS

The large-scale profiling revealed the involvement of 28 miRNAs and 817 genes differentially expressed in LSCC. An integrative analysis comprising predicted and experimentally validated miRNA/mRNA interactions (negatively correlated), resulted in 28 miRNAs and 543 mRNAs. Decreased expression of miR-199b was significantly associated with shorter disease-free survival in LSCC (internal and TCGA datasets). The expression levels of selected miRNAs (miR-199b-5p, miR-29c-3p, miR-204-5p, miR-125b-5p and miR-92a-3p) and genes (COL3A1, COL10A1, ERBB4, HMGA2, HLF, TOP2A, MMP3, MMP13, MMP10 and PPP1R3) were confirmed as altered in LSCC by RT-qPCR. Additionally, a drug target prediction analysis revealed drug combinations based on miRNA and mRNA expression, pointing out novel alternatives to optimize the LSCC treatment.

CONCLUSION

Collectively, these findings provide new insights in the LSCC transcriptional deregulation and potential drug targets.

T-DM1-resistant cells gain high invasive activity via EGFR and integrin cooperated pathways

Ado-trastuzumab emtansine (Kadcyla®; T-DM1) is an antibody-drug conjugate developed to treat trastuzumab-resistant disease. Despite initial favorable outcomes, most patients eventually cease to respond due to developing acquired resistance to T-DM1. Currently, there is no targeted therapy to treat T-DM1-resistant disease. To explore novel therapeutic targets to improve therapeutic efficacy of T-DM1, we generated T-DM1-resistant cells using trastuzumab-resistant JIMT1 cells. We found that the loss of human epidermal growth factor receptor 2 confers T-DM1 resistance, which in turn activates a compensatory mechanism that increases epidermal growth factor receptor (EGFR) expression. Upregulation of EGFR increases the protein levels of α5β1 and αVβ3 integrins, resulting in enhanced motility and invasion of T-DM1-resistant cells. This study delineates previously unappreciated relationships between α5β1 and αVβ3 and suggests that specific integrins should be carefully selected as therapeutic targets to treat T-DM1-resistant disease. Specifically, silencing β1 integrin expression by siRNA in T-DM1-resistant cells destabilizes α5, but increases expression of αV, a critical integrin mediating the invasion and metastases in many different cancers. As a consequence, T-DM1-resistant cells gain metastatic potential and become more invasive. This finding is underscored by the fact that β1 integrin blockage induced by an inhibitory antibody, MAB 13, significantly increases invasion of T-DM1-resistant cells. However, the increased cell invasion induced by β1 integrin blockage can be significantly reduced by either EGFR inhibitor or specific siRNA against αV integrin. The discovery of functional cooperation between EGFR and αV integrin in regulating cell growth and invasion provides an opportunity to develop novel therapeutic strategy by dual-targeting EGFR and specific integrin to overcome T-DM1 resistance.

Myocardin-related transcription factor A (MRTF-A) activity-dependent cell adhesion is correlated to focal adhesion kinase (FAK) activity

The regulation of cell-substrate adhesion is tightly linked to the malignant phenotype of tumor cells and plays a role in their migration, invasion, and metastasis. Focal adhesions (FAs) are dynamic adhesion structures that anchor the cell to the extracellular matrix. Myocardin-related transcription factors (MRTFs), co-regulators of the serum response factor (SRF), regulate expression of a set of genes encoding actin cytoskeletal/FA-related proteins. Here we demonstrated that the forced expression of a constitutively active MRTF-A (CA-MRTF-A) in B16F10 melanoma cells induced the up-regulation of actin cytoskeletal and FA proteins, resulting in FA reorganization and the suppression of cell migration. Expression of CA-MRTF-A markedly increased phosphorylation of focal adhesion kinase (FAK) and paxillin, which are important components for FA dynamics. Notably, FAK activation was triggered by the clustering of up-regulated integrins. Our results revealed that the MRTF-SRF-dependent regulation of cell migration requires both the up-regulation of actin cytoskeletal/FA proteins and the integrin-mediated regulation of FA components via the FAK/Src pathway. We also demonstrated that activation of the MRTF-dependent transcription correlates FAK activation in various tumor cells. The elucidation of the correlation between MRTF and FAK activities would be an effective therapeutic target in focus of tumor cell migration.

MicroRNA‑195 is associated with regulating the pathophysiologic process of human laryngeal squamous cell carcinoma

MicroRNAs (miRNAs) have been reported to be associated with the modulation of tumor development, including alterations associated with the development of human laryngeal squamous cell carcinoma (LSCC). The present study was designed to investigate whether miRNA‑195 was associated with the pathophysiologic process of human LSCC and to identify its potential roles and underlying molecular mechanisms. To determine whether miRNA‑195 serves a role in LSCC, reverse transcription‑quantitative polymerase chain reaction was used to detect miRNA‑195 expression in LSCC tissues. The tumor‑suppressive effect of miRNA‑195 was determined by in vitro assays. Gain‑of‑function studies using miRNA‑195 mimics were performed to investigate cell viability, migration and invasion, and apoptosis in the AMC‑HN‑8 cell line. Western blotting was performed to reveal the molecular mechanisms of miRNA‑195 and its downstream signaling pathways in the LSCC AMC‑HN‑8 cell line. The present study demonstrated that miRNA‑195 is downregulated in primary LSCC tumors. Upregulating miRNA‑195 in vitro suppressed cell viability, migration and invasion in AMC‑HN‑8 cells. Overexpression of miRNA‑195 alone in AMC‑HN‑8 cells was sufficient to induce cell apoptosis, as identified by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Compared with the high expression of miRNA‑195 in AMC‑HN‑8 cells, the expression levels of vascular endothelial growth factor receptor‑II protein and downstream signaling pathway proteins, which were associated with cell viability, migration, invasion and apoptosis, were markedly decreased compared with control or miRNA‑195 negative control treatment group. Together, these data suggest the therapeutic potential of miRNA‑195 in modulating cell growth, migration and apoptosis during the pathophysiological progression of LSCC and that miRNA‑195 may serve as a potential therapeutic target in human LSCC.

Integrin-β5, a miR-185-targeted gene, promotes hepatocellular carcinoma tumorigenesis by regulating β-catenin stability

Background

The tumour microenvironment is essential for cancer progress and metastasis. Integrin-β5 (ITGB5), a member of the integrin family, has been implicated to mediate the interactions of cells with the extracellular matrix (ECM) and promote tumorigenesis in several malignancies. However, the role of ITGB5 in hepatocellular carcinoma (HCC) is still unknown.

Methods

The biological function of ITGB5 in HCC was investigated using migration, colony formation assays. The potential molecular mechanism of ITGB5 in regulating HCC tumorigenesis and β-catenin stabilization was investigated by western blotting, co-immunoprecipitation and ubiquitination assays. The expression level of ITGB5 mediated by miR-185 was confirmed by bioinformatic analysis, luciferase assay. The clinical significance of ITGB5 was based on human tissue microarray (TMA) analysis.

Results

Here, we found that the expression of ITGB5 is increased in HCC tissues. Elevated ITGB5 markedly facilitates HCC cell migration and tumorigenesis in vitro and in vivo. Further mechanistic studies revealed that ITGB5, as a partner of β-catenin, directly interacts with β-catenin and inhibits its degradation, thus leading to WNT/β-catenin activity. Subsequently, we also found that ITGB5 is a direct targeted gene of miR-185. The downregulation of miR-185 in HCC cells promotes an increase in ITGB5. An additional increase of ITGB5 is associated with β-catenin upregulation and a miR-185 decrease in HCC tissues.

Conclusions

Our data reveal that the miR-185-ITGB5-β-catenin pathway plays an important role in HCC tumorigenesis, and ITGB5 may be a promising specific target for HCC therapy.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0691-9) contains supplementary material, which is available to authorized users.

RGD-Binding Integrins in Head and Neck Cancers

Alterations in integrin expression and function promote tumour growth, invasion, metastasis and neoangiogenesis. Head and neck cancers are highly vascular tumours with a tendency to metastasise. They express a wide range of integrin receptors. Expression of the αv and β1 subunits has been explored relatively extensively and linked to tumour progression and metastasis. Individual receptors αvβ3 and αvβ5 have proved popular targets for diagnostic and therapeutic agents but lesser studied receptors, such as αvβ6, αvβ8, and β1 subfamily members, also show promise. This review presents the current knowledge of integrin expression and function in squamous cell carcinoma of the head and neck (HNSCC), with a particular focus on the arginine-glycine-aspartate (RGD)-binding integrins, in order to highlight the potential of integrins as targets for personalised tumour-specific identification and therapy.

Current relevance of hypoxia in head and neck cancer

Head and Neck cancer (HNC) is a complex mix of cancers and one of the more common cancers with a relatively poor prognosis. One of the factors that may assist us in predicting survival and allow us to adjust our treatment strategies is the presence of tumor hypoxia. In this overview we aim to evaluate the current evidence and potential clinical relevance of tumor hypoxia in head and neck cancer according to an extensive search of current literature.An abundance of evidence and often contradictory evidence is found in the literature. Even the contradictory evidence and comparisons are difficult to judge as criteria and methodologies differ greatly, furthermore few prospective observational studies exist for verification of the pre-clinical studies. Despite these discrepancies there is clear evidence of associations between prognosis and poor tumor oxygenation biomarkers such as HIF-1α, GLUT-1 and lactate, though these associations are not exclusive. The use of genetic markers is expanding and will probably lead to significantly more and complex evidence. The lack of oxygenation in head and neck tumors is of paramount importance for the prediction of treatment outcomes and prognosis. Despite the wide array of conflicting evidence, the drive towards non-invasive prediction of tumor hypoxia should continue.

Combined targeting of TGF-β1 and integrin β3 impairs lymph node metastasis in a mouse model of non-small-cell lung cancer

Background

Transforming Growth Factor beta (TGF-β) acts as a tumor suppressor early in carcinogenesis but turns into tumor promoter in later disease stages. In fact, TGF-β is a known inducer of integrin expression by tumor cells which contributes to cancer metastatic spread and TGF-β inhibition has been shown to attenuate metastasis in mouse models. However, carcinoma cells often become refractory to TGF-β-mediated growth inhibition. Therefore identifying patients that may benefit from anti-TGF-β therapy requires careful selection.

Methods

We performed in vitro analysis of the effects of exposure to TGF-β in NSCLC cell chemotaxis and adhesion to lymphatic endothelial cells. We also studied in an orthotopic model of NSCLC the incidence of metastases to the lymph nodes after inhibition of TGF-β signaling, β3 integrin expression or both.

Results

We offer evidences of increased β3-integrin dependent NSCLC adhesion to lymphatic endothelium after TGF-β exposure. In vivo experiments show that targeting of TGF-β and β3 integrin significantly reduces the incidence of lymph node metastasis. Even more, blockade of β3 integrin expression in tumors that did not respond to TGF-β inhibition severely impaired the ability of the tumor to metastasize towards the lymph nodes.

Conclusion

These findings suggest that lung cancer tumors refractory to TGF-β monotherapy can be effectively treated using dual therapy that combines the inhibition of tumor cell adhesion to lymphatic vessels with stromal TGF-β inhibition.

The prognostic implications of microvascular density and lymphatic vessel density in esophageal squamous cell carcinoma: Comparative analysis between the traditional whole sections and the tissue microarray

Focal distribution of microvascular and lymphatic vessels is a critical issue in cancer, and is measured by tissue microarray (TMA) construction from paraffin-embedded surgically obtained tissues, a process that may not accurately reflect true focal distribution. The aim of this study was to assess the concordance of microvascular density (MVD) and lymphatic vessel density (LVD) in TMAs with corresponding whole sections, and to correlate the MVD or LVD with clinicopathological parameters in 124 cases of esophageal squamous cell carcinoma (ESCC). MVD, determined by CD105 immunohistochemistry of whole sections, was strongly associated with lymph node metastasis (p=0.000) and pTNM stage (p=0.001). Kaplan-Meier survival analysis showed that increasing CD105 microvessel count correlated with decreasing survival (p<0.001). The same result was acquired when MVD was calculated from tissue microarrays. Analysis of continuous data showed a highly significant correlation between whole sections and TMA data (Pearson r=0.522, p<0.001). Increasing LVD, as determined by D2-40 immunohistochemistry of whole sections, correlated with decreasing survival, but this relationship was undetectable using TMAs. In conclusion, we demonstrate that for the selected endothelial markers, TMAs can provide a realistic and reliable estimate of the extent of MVD, but not LVD in ESCC samples.

Overexpression of integrin αv correlates with poor prognosis in colorectal cancer

AIMS

Integrin αv subunits are involved in tumour angiogenesis and tumour progression in various types of cancers. Clinical trials evaluating agents targeting integrin αv are ongoing. Integrin αv expression has been reported in several cancers in association with tumour progression or poor survival. However, no study has addressed the prognostic influence of integrin αv expression on survival of patients with colorectal cancer (CRC).

METHODS

Immunohistochemical staining of integrin αv was performed in 198 CRC samples to evaluate its prognostic significance.

RESULTS

High expression of integrin αv was observed in 58.1% (115/189) of colorectal adenocarcinoma samples, while only in 11.5% (3/26) of tubular adenoma samples and in none of normal mucosa or hyperplastic polyp samples. It was more frequently found in female patients and less frequently observed in well differentiated tumours. The proportion of cases with high expression of integrin αv showed an increasing trend with increased T stage (p=0.032), N stage (p=0.006) and TNM stage (p=0.001). Patients displaying exuberant expression of integrin αv showed shorter overall survival (p=0.001) and disease-free survival (p=0.004). Elevated integrin αv expression was an independent prognostic factor for overall survival (HR: 2.04, 95% CI 1.16 to 3.56; p=0.013) and disease-free survival (HR: 2.19, 95% CI 1.16 to 4.13; p=0.015).

CONCLUSIONS

Overexpression of integrin αv is associated with advanced T and N stage and as an independent prognostic factor in CRC.

Cilengitide, a small molecule antagonist, targeted to integrin αν inhibits proliferation and induces apoptosis of laryngeal cancer cells in vitro

Cilengitide is a chemical synthesis cyclopeptide containing RGD sequence, which can be used as a small molecule antagonist targeted to integrin αν (ITGAV). The aim of present study was to investigate the effect on proliferation and cell apoptosis of the cilengitide in laryngeal cancer cells. In the study, we have treatmented the cultured cells of laryngeal cancer (Hep-2) with cilengitide. After the medication, the proliferation of the Hep-2 cells was detected by MTT assay, the expression of ITGAV was detected by RT-PCR and the activity of caspase-3 protein was detected by a specialized kit. RGD linear peptides (GRGDSP), non-RGD linear peptide (GRGESP), and 5-fluorouracil (5-Fu) were used as controls. Results showed that the proliferation of Hep-2 cells was signally inhibited by the cilengitide with a time and dose compliance. Its inhibition effect was significantly higher than that of 5-Fu and GRGDSP, but the GRGESP showed no obvious inhibitory effect. After intervene of cilengitide, the activity of caspase-3 protein of Hep-2 cells was significantly increased, and the expression of ITGAV was significantly decreased. 5-Fu significantly inhibited the proliferation of Hep-2 cells, but no significant changes of ITGAV expression were observed. In conclusion, cilengitide can significantly down-regulate ITGAV expression and inhibit cell proliferation in laryngeal cancer cells, it will also to induce cell apoptosis through caspase-3 pathway. Therefore, it could be as a kind of effective chemotherapy drugs that will be used in clinical treatment of the laryngeal cancer.