Integrins in Head and Neck Squamous Cell Carcinoma (HNSCC): A Review of the Current Literature

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.

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.

Eptifibatide-induced acute profound thrombocytopenia: a case report

BACKGROUND

The interactions among cells or among cells and components of the extracellular matrix, is a crucial pathophysiological process involving some molecules collectively known as adhesion molecules (CAMs). Glycoprotein IIb / IIIa receptors are only restricted to blood platelets and they bind fibrinogen and adhesion proteins such as fibronectin, vitronectin, von Willebrand factor to form cross bridges between adjacent platelets. IIb/IIIa receptor antagonists are an object of intense research activity for target therapy worldwide during the last decades. Three GPIIb/IIIa inhibitors, abciximab, tirofiban, and eptifibatide, have been approved for clinical use. Profound thrombocytopenia is an uncommon but clinically important complication of glycoprotein IIb/IIIa inhibitors.

CASE PRESENTATION

This case report discusses a forty-four-year-old male patient with acute coronary syndrome who underwent percutaneous coronary intervention and developed profound thrombocytopenia within 4 hours of first administration of eptifibatide.

CONCLUSION

This report adds another case of eptifibatide-induced thrombocytopenia to the medical literature and endorses the importance of platelet count monitoring after initiating therapy with this agent.

ADAM 10 is over expressed in oral squamous cell carcinoma and contributes to invasive behaviour through a functional association with αvβ6 integrin

A disintegrin and metalloprotease (ADAM) proteins are upregulated in cancer and can interact with integrin receptors. We investigated whether such interactions may have functional significance in oral squamous cell carcinoma (OSCC). ADAM 10 expression was increased in OSCC tissue and cell lines compared to normal oral mucosa. Silencing of ADAM 10 reduced migration and invasion specifically in OSCC cells over-expressing αvβ6 integrin. This may result from ADAM 10-induced up-regulation of MMPs. We conclude ADAM 10 may influence OSCC invasion by functionally interacting with αvβ6 integrin which we have previously shown is over expressed in OSCC.

Molecular and cellular processes underlying the hallmarks of head and neck cancer

The hallmarks of cancer were updated by Hanahan and Weinberg in 2011. Here we discuss the updated hallmarks in relation to what is known of the molecular and cellular processes underlying the development of head and neck squamous cell carcinoma (HNSCC). Several mechanisms are described, and recent surveys of HNSCC suggest a limited number of mutations, from which more mechanisms may emerge. There are also epigenetic changes to the control of normal processes. More than one mechanism underlies each hallmark. Processes essential to the development of HNSCC need not be essential to the proliferation of the fully developed tumour. Attention is paid to the emerging hallmarks, deregulation of cellular energy metabolism and evasion of immune destruction, and enabling characteristics, genome instability and mutation and tumour-promoting inflammation. HNSCC may adapt to hypoxia, suppress HLA expression, and express Toll-like receptors to facilitate inflammation, which support the proliferation of the tumour.

Evolving 'omics' technologies for diagnostics of head and neck cancer

Squamous cell carcinoma of head and neck (SCCHN) is the sixth most common malignancy and is a major cause of cancer morbidity and mortality worldwide. As with most solid cancers, the cure rate for SCCHN is excellent if tumors are diagnosed early in the course of the disease. Early diagnosis of cancer remains difficult because of the lack of specific symptoms in early disease as well as the limited understanding of etiology and oncogenesis. Advances in proteomics and genomics contribute to the understanding of the pathophysiology of neoplasia, cancer diagnosis and anticancer drug discovery. The powerful 'omics' technologies have opened new avenues towards biomarker discovery, identification of signaling molecules associated with cell growth, cell death, cellular metabolism and early detection of cancer. Analysis of tumor-specific omics profiles provided a unique opportunity to diagnose, classify, and detect malignant disease; to better understand and define the behavior of specific tumors; and to provide direct and targeted therapy. These technologies however still require integration and standardization of techniques and validation against accepted clinical and pathologic parameters. This article provides a summary of technologies, potential clinical applications, and challenges of omics in head and neck cancer.

High-resolution copy number and gene expression microarray analyses of head and neck squamous cell carcinoma cell lines of tongue and larynx

Gene amplifications and deletions are frequent in head and neck squamous cell carcinomas (SCC) but the association of these alterations with gene expression is mostly unknown. Here, we characterized genome-wide copy number and gene expression changes on microarrays for 18 oral tongue SCC (OTSCC) cell lines. We identified a number of altered regions including nine high-level amplifications such as 6q12-q14 (CD109, MYO6), 9p24 (JAK2, CD274, SLC1A1, RLN1), 11p12-p13 (TRAF6, COMMD9, TRIM44, FJX1, CD44, PDHX, APIP), 11q13 (FADD, PPFIA1, CTTN), and 14q24 (ABCD4, HBLD1, LTBP2, ZNF410, COQ6, ACYP1, JDP2) where 9% to 64% of genes showed overexpression. Across the whole genome, 26% of the amplified genes had associated overexpression in OTSCC. Furthermore, our data implicated that OTSCC cell lines harbored similar genomic alterations as laryngeal SCC cell lines We have previously analyzed, suggesting that despite differences in clinicopathological features there are no marked differences in molecular genetic alterations of these two HNSCC sites. To identify genes whose expression was associated with copy number increase in head and neck SCC, a statistical analysis for oral tongue and laryngeal SCC cell line data were performed. We pinpointed 1,192 genes that had a statistically significant association between copy number and gene expression. These results suggest that genomic alterations with associated gene expression changes play an important role in the malignant behavior of head and neck SCC. The identified genes provide a basis for further functional validation and may lead to the identification of novel candidates for targeted therapies. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.

Expression of adhesion molecules during normal pregnancy

We review the available information regarding the role of adhesive molecules as potential participants in the complex events of fertilization, embryogenesis, implantation and placentation. Studies that specifically relate to the expression and modulation of adhesive molecules in fertilization, embryogenesis, and implantation have been identified in the literature and by Medline searches. Cell-cell and cell-extracellular matrix interactions play a critical role in various developmental processes and in the cascade of events that lead to implantation and to the normal development of the fetus during pregnancy. Adhesion molecules influence, directly or indirectly, numerous aspects of cell behaviour, cell migration, cell growth, cell survival, cell proliferation, angiogenesis, invasion and metastasis.