Barry L. Ziober

Transcriptomic dissection of tongue squamous cell carcinoma

BackgroundThe head and neck/oral squamous cell carcinoma (HNOSCC) is a diverse group of cancers, which develop from many different anatomic sites and are associated with different risk factors and genetic characteristics. The oral tongue squamous cell carcinoma (OTSCC) is one of the most common types of HNOSCC. It is significantly more aggressive than other forms of HNOSCC, in terms of local invasion and spread. In this study, we aim to identify specific transcriptomic signatures that associated with OTSCC.ResultsGenome-wide transcriptomic profiles were obtained for 53 primary OTSCCs and 22 matching normal tissues. Genes that exhibit statistically significant differences in expression between OTSCCs and normal were identified. These include up-regulated genes (MMP1, MMP10, MMP3, MMP12, PTHLH, INHBA, LAMC2, IL8, KRT17, COL1A2, IFI6, ISG15, PLAU, GREM1, MMP9, IFI44, CXCL1), and down-regulated genes (KRT4, MAL, CRNN, SCEL, CRISP3, SPINK5, CLCA4, ADH1B, P11, TGM3, RHCG, PPP1R3C, CEACAM7, HPGD, CFD, ABCA8, CLU, CYP3A5). The expressional difference of IL8 and MMP9 were further validated by real-time quantitative RT-PCR and immunohistochemistry. The Gene Ontology analysis suggested a number of altered biological processes in OTSCCs, including enhancements in phosphate transport, collagen catabolism, I-kappaB kinase/NF-kappaB signaling cascade, extracellular matrix organization and biogenesis, chemotaxis, as well as suppressions of superoxide release, hydrogen peroxide metabolism, cellular response to hydrogen peroxide, keratinization, and keratinocyte differentiation in OTSCCs.ConclusionIn summary, our study provided a transcriptomic signature for OTSCC that may lead to a diagnosis or screen tool and provide the foundation for further functional validation of these specific candidate genes for OTSCC.

Gene expression signature predicts lymphatic metastasis in squamous cell carcinoma of the oral cavity

Metastasis via the lymphatics is a major risk factor in squamous cell carcinoma of the oral cavity (OSCC). We sought to determine whether the presence of metastasis in the regional lymph node could be predicted by a gene expression signature of the primary tumor. A total of 18 OSCCs were characterized for gene expression by hybridizing RNA to Affymetrix U133A gene chips. Genes with differential expression were identified using a permutation technique and verified by quantitative RT–PCR and immunohistochemistry. A predictive rule was built using a support vector machine, and the accuracy of the rule was evaluated using crossvalidation on the original data set and prediction of an independent set of four patients. Metastatic primary tumors could be differentiated from nonmetastatic primary tumors by a signature gene set of 116 genes. This signature gene set correctly predicted the four independent patients as well as associating five lymph node metastases from the original patient set with the metastatic primary tumor group. We concluded that lymph node metastasis could be predicted by gene expression profiles of primary oral cavity squamous cell carcinomas. The presence of a gene expression signature for lymph node metastasis indicates that clinical testing to assess risk for lymph node metastasis should be possible.

Carbon nanopipettes for cell probes and intracellular injection

We developed integrated, carbon-based pipettes with nanoscale dimensions (CNP) that can probe cells with minimal intrusion, inject fluids into the cells, and concurrently carry out electrical measurements. Our manufacturing technique does not require cumbersome nanoassembly and is amenable to mass production. Using CNPs, we demonstrate the injection of reagents into cells with minimal intrusion and without inhibiting cell growth.

Adhesive Mechanisms Regulating Invasion and Metastasis in Oral Cancer

It is the relentless invasion and growth into surrounding tissue that characterize oral squamous cell carcinoma. Metastasis is perhaps the most challenging and important aspect of cancer progression, in that it generally signifies limited survival and ineffective therapy. Inherent in metastasis is invasion, the process by which cells infiltrate into adjacent tissues, degrading basement membranes and extracellular matrix and disrupting tissue architecture and sometimes organ function. The factors that regulate these processes are complex and likely involve loss of the controls that are normally in place in physiologic tissue modeling. Adhesion receptors and their ligands are important in modulating not only invasion of oral squamous cell carcinoma cells but also their survival and proliferation. Normal oral mucosal epithelial cells use integrins to maintain their anchorage to the basement membrane, whereas the formation of stratifying cell layers depends on the formation of intercellular adhesions mediated by cadherins. The process of squamous cell carcinoma invasion and dissemination requires active cell migration through the extracellular matrix with the simultaneous remodeling of intercellular adhesions. Integrins are clearly important in the invasive process, whereas intercellular adhesion receptors restrain invasion and promote a more differentiated phenotype.

Lab-On-A-Chip for Oral Cancer Screening and Diagnosis

Oral squamous cell carcinoma (OSCC) is a disfiguring and deadly cancer. Despite advances in therapy, many patients continue to face a poor prognosis. Early detection is an important factor in determining the survival of patients with OSCC. No accurate, cost‐efficient, and reproducible method exists to screen patients for OSCC. As a result, many patients are diagnosed at advanced stages of the disease. Early detection would identify patients, facilitating timely treatment and close monitoring. Mass screening requires a rapid oral cancer diagnostic test that can be used in a clinical setting. Current diagnostic techniques for OSCC require modern laboratory facilities, sophisticated equipment, and elaborate and lengthy processing by skilled personnel. The lab‐on‐chip technology holds the promise of replacing these techniques with miniaturized, integrated, automated, inexpensive diagnostic devices. This article describes lab‐on‐chip devices for biomarker‐based identification of oral cancer. Similar methods can be employed for the screening of other types of cancers.

The extracellular matrix in oral squamous cell carcinoma: Friend or foe?

Oral squamous cell carcinoma is a disfiguring, highly invasive and metastatic cancer. Despite advances in detection and therapy, many patients will continue to face a poor prognosis. It is well established that the predominate factor determining overall survival in patients with oral squamous cell carcinoma is lymph node involvement. Tumor growth and progression to invasive cancer requires tumor cell interactions with the extracellular matrix. An understanding of how the extracellular matrix influences tumor development and invasion is fundamental in the development of new prognostic indicators and treatment strategies for oral squamous cell carcinoma. In this review, we summarize how changes in the extracellular matrix contribute to oral cancer development.

Lab-on-a-chip technologies for oral-based cancer screening and diagnostics: capabilities, issues, and prospects.

Abstract:u2002 The design of a microfluidic lab‐on‐a‐chip system for point‐of‐care cancer screening and diagnosis of oral squamous cell carcinoma (OSCC) is presented. The chip is based on determining a ∼30‐gene transcription profile in cancer cells isolated from oral fluid samples. Microfluidic cell sorting using magnetic beads functionalized with an antibody against cancer‐specific cell‐surface antigens (e.g., epithelial cell adhesion molecule [EpCAM]) is described. A comprehensive cancer diagnostics chip will integrate microfluidic components for cell lysis, nucleic acid extraction, and amplification and detection of a panel of mRNA isolated from a subpopulation of cancer cells contained in a clinical specimen.

Tumor Deposition of Laminin‐5 and the Relationship With Perineural Invasion

Objectives/Hypothesis Perineural invasion (PNI) is increasingly being recognized as an important indicator of aggressiveness in head and neck squamous cell carcinoma. The mechanisms of PNI are poorly understood. Laminin‐5, an important basement membrane constituent, has been shown to be essential in head and neck squamous cell carcinoma invasion and motility. We hypothesized that tumors exhibiting increased expression of laminin‐5 are more likely to be neurotropic.

Integrins in head and neck squamous cell carcinoma invasion

Objective To relate the invasive properties of different squamous cell cancer cell lines to the function and expression of the integrins.

Dysregulation of Hypoxia Inducible Factor-1α in Head and Neck Squamous Cell Carcinoma Cell Lines Correlates With Invasive Potential†

Objectives/Hypothesis Tumor hypoxia appears to be closely associated with tumor propagation, malignant progression, and resistance to radiotherapy. Hypoxia inducible factor‐1α (HIF‐1α) is a transcription factor that is upregulated under hypoxic conditions and activates hypoxic adaptation pathways which include neovascularization, erythropoiesis, and glycolysis. Hypoxia inducible factor‐1α is under tight regulation with undetectable levels of expression in normoxia and robust expression in hypoxia. Mutations that activate oncogenes or inactivate tumor suppressor genes increase the expression of HIF‐1α. Furthermore, it has been demonstrated that HIF‐1α is overexpressed in head and neck squamous cell carcinoma and that the degree of expression has predictive and prognostic significance for patients undergoing radiotherapy. The study investigated whether overexpression of HIF‐1α in head and neck squamous cell carcinoma results from a physiological response to local hypoxia or from oncogenic mutational progression.