Chromosome 11q13 amplification in head and neck squamous cell carcinoma. Association with poor prognosis

Liprin-α1 contributes to oncogenic MAPK signaling by counteracting ERK activity

PTPRF interacting protein alpha 1 (PPFIA1) encodes for liprin-α1, a member of the leukocyte common antigen-related protein tyrosine phosphatase (LAR-RPTPs)-interacting protein family. Liprin-α1 localizes to adhesive and invasive structures in the periphery of cancer cells, where it modulates migration and invasion in head and neck squamous cell carcinoma (HNSCC) and breast cancer. To study the possible role of liprin-α1 in anticancer drug responses, we screened a library of oncology compounds in cell lines with high endogenous PPFIA1 expression. The compounds with the highest differential responses between high PPFIA1-expressing and silenced cells across cell lines were inhibitors targeting mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinases (ERK) signaling. KRAS proto-oncogene, GTPase (KRAS)-mutated MDA-MB-231 cells were more resistant to trametinib upon PPFIA1 knockdown compared with control cells. In contrast, liprin-α1-depleted HNSCC cells with low RAS activity showed a context-dependent response to MEK/ERK inhibitors. Importantly, we showed that liprin-α1 depletion leads to increased p-ERK1/2 levels in all our studied cell lines independent of KRAS mutational status, suggesting a role of liprin-α1 in the regulation of MAPK oncogenic signaling. Furthermore, liprin-α1 depletion led to more pronounced redistribution of RAS proteins to the cell membrane. Our data suggest that liprin-α1 is an important contributor to oncogenic RAS/MAPK signaling, and the status of liprin-α1 may assist in predicting drug responses in cancer cells in a context-dependent manner.

Molecular and functional insight into focal adhesion kinases: Therapeutic implications for oral malignancies

Oral carcinoma is the sixth most common cancer globally, with one death occurring every hour. Focal adhesion kinase (FAK) is an intercellular protein tyrosine kinase, a key indicator of the development of oral cancer. FAK overexpression leads to the initiation and significant progression of metastasis in head and neck cancers, indicating its vital role in cancer progression and potential as a biomarker for early oral malignant transformation. The present review elaborates on FAK's function in oral malignancies since it could serve as a biomarker of the initial stages of oral malignant transformation and a possible predictive factor for risk assessment.

FADS2 function at the major cancer hotspot 11q13 locus alters fatty acid metabolism in cancer

Dysregulation of fatty acid metabolism and de novo lipogenesis is a key driver of several cancer types through highly unsaturated fatty acid (HUFA) signaling precursors such as arachidonic acid. The human chromosome 11q13 locus has long been established as the most frequently amplified in a variety of human cancers. The fatty acid desaturase genes (FADS1, FADS2 and FADS3) responsible for HUFA biosynthesis localize to the 11q12-13.1 region. FADS2 activity is promiscuous, catalyzing biosynthesis of several unsaturated fatty acids by Δ6, Δ8, and Δ4 desaturation. Our main aim here is to review known and putative consequences of FADS2 dysregulation due to effects on the 11q13 locus potentially driving various cancer types. FADS2 silencing causes synthesis of sciadonic acid (5Z,11Z,14Z-20:3) in MCF7 cells and breast cancer in vivo. 5Z,11Z,14Z-20:3 is structurally identical to arachidonic acid (5Z,8Z,11Z,14Z-20:4) except it lacks the internal Δ8 double bond required for prostaglandin and leukotriene synthesis, among other eicosanoids. Palmitic acid has substrate specificity for both SCD and FADS2. Melanoma, prostate, liver and lung cancer cells insensitive to SCD inhibition show increased FADS2 activity and sapienic acid biosynthesis. Elevated serum mead acid levels found in hepatocellular carcinoma patients suggest an unsatisfied demand for arachidonic acid. FADS2 circular RNAs are at high levels in colorectal and lung cancer tissues. FADS2 circular RNAs are associated with shorter overall survival in colorectal cancer patients. The evidence thusfar supports an effort for future research on the role of FADS2 as a tumor suppressor in a range of neoplastic disorders.

Updates on Larynx Cancer: Risk Factors and Oncogenesis

Laryngeal cancer is a very common tumor in the upper aero-digestive tract. Understanding its biological mechanisms has garnered significant interest in recent years. The development of laryngeal squamous cell carcinoma (LSCC) follows a multistep process starting from precursor lesions in the epithelium. Various risk factors have been associated with laryngeal tumors, including smoking, alcohol consumption, opium use, as well as infections with HPV and EBV viruses, among others. Cancer development involves multiple steps, and genetic alterations play a crucial role. Tumor suppressor genes can be inactivated, and proto-oncogenes may become activated through mechanisms like deletions, point mutations, promoter methylation, and gene amplification. Epigenetic modifications, driven by miRNAs, have been proven to contribute to LSCC development. Despite advances in molecular medicine, there are still aspects of laryngeal cancer that remain poorly understood, and the underlying biological mechanisms have not been fully elucidated. In this narrative review, we examined the literature to analyze and summarize the main steps of carcinogenesis and the risk factors associated with laryngeal cancer.

Cyclins and cyclin-dependent kinases: from biology to tumorigenesis and therapeutic opportunities

The discussion on cell proliferation cannot be continued without taking a look at the cell cycle regulatory machinery. Cyclin-dependent kinases (CDKs), cyclins, and CDK inhibitors (CKIs) are valuable members of this system and their equilibrium guarantees the proper progression of the cell cycle. As expected, any dysregulation in the expression or function of these components can provide a platform for excessive cell proliferation leading to tumorigenesis. The high frequency of CDK abnormalities in human cancers, together with their druggable structure has raised the possibility that perhaps designing a series of inhibitors targeting CDKs might be advantageous for restricting the survival of tumor cells; however, their application has faced a serious concern, since these groups of serine-threonine kinases possess non-canonical functions as well. In the present review, we aimed to take a look at the biology of CDKs and then magnify their contribution to tumorigenesis. Then, by arguing the bright and dark aspects of CDK inhibition in the treatment of human cancers, we intend to reach a consensus on the application of these inhibitors in clinical settings.

Etiologia do Carcinoma Epidermóide de Hipofaringe

A carcinogênese é uma alteração do controle do crescimento celular devido a uma exposição prolongada a algum agente com potencial mutagênico. O tabagismo é um importante determinante do risco de câncer de faringe, e a associação com o etilismo aumenta ainda mais este risco. Fatores nutricionais, como na síndrome de Plummer-Vinson, em que há uma anemia ferropriva, parecem ter também importância. Como apenas uma fração dos indivíduos expostos a tabagismo e etilismo desenvolvem câncer, sugere-se que fatores específicos do hospedeiro estabeleçam suscetibilidade diferente. Assim, o sexo masculino é o mais acometido, bem como a sexta e sétima décadas. Encontrou-se um risco relativo maior com a exposição a certas substâncias. Portadores de um primeiro tumor, exposição a radioterapia prévia e aos vírus da papilomatose humana (HPV) e, menos freqüentemente, EBV, apresentam maior risco de desenvolvimento de um câncer faríngeo. Parece ainda haver uma predisposição familiar, bem como uma correlação com a ativação de oncogens e a inativação de gens supressores de tumores, como o p53.

Liprins in oncogenic signaling and cancer cell adhesion

Liprins are a multifunctional family of scaffold proteins, identified by their involvement in several important neuronal functions related to signaling and organization of synaptic structures. More recently, the knowledge on the liprin family has expanded from neuronal functions to processes relevant to cancer progression, including cell adhesion, cell motility, cancer cell invasion, and signaling. These proteins consist of regions, which by prediction are intrinsically disordered, and may be involved in the assembly of supramolecular structures relevant for their functions. This review summarizes the current understanding of the functions of liprins in different cellular processes, with special emphasis on liprins in tumor progression. The available data indicate that liprins may be potential biomarkers for cancer progression and may have therapeutic importance.

Targeted therapies for non-HPV-related head and neck cancer: challenges and opportunities in the context of predictive, preventive, and personalized medicine

Head and neck squamous cell carcinoma (HNSCC) develops in the mucosal lining of the upper aerodigestive tract, principally as a result of exposure to carcinogens present in tobacco products and alcohol, with oncogenic papillomaviruses also being recognized as etiological agents in a limited proportion of cases. As such, there is considerable scope for prevention of disease development and progression. However, despite multimodal approaches to treatment, tumor recurrence and metastatic disease are common problems, and clinical outcome is unsatisfactory. As our understanding of the genetics and biochemical aberrations in HNSCC has improved, so the development and use of molecularly targeted drugs to combat the disease have come to the fore. In this article, we review molecular mechanisms that alter signal transduction downstream of the epidermal growth factor receptor (EGFR) as well as those that perturb orderly cell cycle progression, such as p53 mutation, cyclin overexpression, and loss of cyclin-dependent kinase inhibitor function. We outline some of the tactics that have been employed to combat the altered biochemistry. These include blockade of the EGFR using humanized monoclonal antibodies such as cetuximab and small molecule tyrosine kinase inhibitors (TKIs) such as erlotinib/gefitinib and subsequent generations of TKIs, restoration of p53 function using MIRA compounds, and inhibition of cyclin-dependent kinase and aurora kinase activity using drugs such as palbociclib and alisertib. Knowledge of the underlying molecular mechanisms may be utilizable in order to predict disease behavior and tailor therapeutic interventions in a more personalized approach to improve clinical response. Use of liquid biopsy, omics platforms, and salivary diagnostics hold promise in this regard.

Liprin-α1 modulates cancer cell signaling by transmembrane protein CD82 in adhesive membrane domains linked to cytoskeleton

Background

PPFIA1 is located at the 11q13 region commonly amplified in cancer. The protein liprin-α1 encoded by PPF1A1 contributes to the adhesive and invasive structures of cytoskeletal elements and is located at the invadosomes in cancer cells. However, the precise mechanism of liprin-α1 function in cancer progression has remained elusive.

Methods

Invasion regulating activity of liprin-α1 was examined by analyzing the functions of squamous cell carcinoma of head and neck (HNSCC) cell lines in three-dimensional collagen I after RNAi mediated gene knockdown. Transcriptome profiling and Gene Set Enrichment Analysis from HNSCC and breast cancer cells were used to identify expression changes relevant to specific cellular localizations, biological processes and signaling pathways after PPFIA1 knockdown. The significance of the results was assessed by relevant statistical methods (Wald and Benjamini-Hochberg). Localization of proteins associated to liprin-α1 was studied by immunofluorescence in 2D and 3D conditions. The association of PPFIA1 amplification to HNSCC patient survival was explored using The Cancer Genome Atlas data.

Results

In this study, we show that liprin-α1 regulates biological processes related to membrane microdomains in breast carcinoma, as well as protein trafficking, cell-cell and cell-substrate contacts in HNSCC cell lines cultured in three-dimensional matrix. Importantly, we show that in all these cancer cells liprin-α1 knockdown leads to the upregulation of transmembrane protein CD82, which is a suppressor of metastasis in several solid tumors.

Conclusions

Our results provide novel information regarding the function of liprin-α1 in biological processes essential in cancer progression. The results reveal liprin-α1 as a novel regulator of CD82, linking liprin-α1 to the cancer cell invasion and metastasis pathways.

Electronic supplementary material

The online version of this article (10.1186/s12964-018-0253-y) contains supplementary material, which is available to authorized users.

Phosphorylated FADD is not prognostic for local control in T1-T2 supraglottic laryngeal carcinoma treated with radiotherapy

OBJECTIVE

The Fas-Associated Death Domain (FADD) gene is located in the chromosome 11q13-region and frequently is amplified in head and neck squamous cell carcinoma. Expression of FADD and its phosphorylated isoform (pFADD) have been associated with aggressive tumor growth, lymph node metastasis, and overall survival. Previously, we demonstrated that pFADD expression was related to a significantly improved local control in early stage (tumor [T]1 to T2) glottic laryngeal squamous cell carcinoma (LSCC). The aim of this study was to examine the prognostic value of pFADD and FADD in T1 to T2 supraglottic LSCC treated with primarily radiotherapy.

METHODS

Tumor tissue sections of 60 patients with T1 to T2 supraglottic LSCC treated with primarily radiotherapy were assessed immunohistochemically for expression of pFADD and FADD. Expression percentages and clinical parameters and their associations with clinical outcome were studied using Cox regression and Kaplan-Meier survival analyses. Expression percentages in supraglottic and glottic LSCC were compared using the Mann-Whitney U test.

RESULTS

Expression of pFADD and FADD in supraglottic and glottic LSCC did not significantly differ. In supraglottic LSCC, both pFADD and FADD did not show prognostic value for local control (hazard ratio [HR] 1.00, 95% confidence interval [CI] 0.98-1.03; HR 1.03, 95% CI 0.60-1.78, respectively) and overall survival (HR 0.99, 95% CI 0.98-1.01; HR 1.19, 95% CI 0.83-1.71 respectively). In this cohort, lymph node status was the best predictor for local control (HR 3.73, 95% CI 1.30-10.67).

CONCLUSION

In this homogeneous cohort of T1 to T2 supraglottic LSCC primarily treated with radiotherapy, lymph node status was associated with local recurrence, whereas the expression of pFADD was not.

LEVEL OF EVIDENCE

NA. Laryngoscope, 127:E301-E307, 2017.

Integrated genomics approach to identify biologically relevant alterations in fewer samples

BACKGROUND

Several statistical tools have been developed to identify genes mutated at rates significantly higher than background, indicative of positive selection, involving large sample cohort studies. However, studies involving smaller sample sizes are inherently restrictive due to their limited statistical power to identify low frequency genetic variations.

RESULTS

We performed an integrated characterization of copy number, mutation and expression analyses of four head and neck cancer cell lines - NT8e, OT9, AW13516 and AW8507 - by applying a filtering strategy to prioritize for genes affected by two or more alterations within or across the cell lines. Besides identifying TP53, PTEN, HRAS and MET as major altered HNSCC hallmark genes, this analysis uncovered 34 novel candidate genes altered. Of these, we find a heterozygous truncating mutation in Nuclear receptor binding protein, NRBP1 pseudokinase gene, identical to as reported in other cancers, is oncogenic when ectopically expressed in NIH-3 T3 cells. Knockdown of NRBP1 in an oral carcinoma cell line bearing NRBP1 mutation inhibit transformation and survival of the cells.

CONCLUSIONS

In overall, we present the first comprehensive genomic characterization of four head and neck cancer cell lines established from Indian patients. We also demonstrate the ability of integrated analysis to uncover biologically important genetic variation in studies involving fewer or rare clinical specimens.

Genome-Wide Loss of Heterozygosity and DNA Copy Number Aberration in HPV-Negative Oral Squamous Cell Carcinoma and Their Associations with Disease-Specific Survival

Oral squamous cell cancer of the oral cavity and oropharynx (OSCC) is associated with high case-fatality. For reasons that are largely unknown, patients with the same clinical and pathologic staging have heterogeneous response to treatment and different probability of recurrence and survival, with patients with Human Papillomavirus (HPV)-positive oropharyngeal tumors having the most favorable survival. To gain insight into the complexity of OSCC and to identify potential chromosomal changes that may be associated with OSCC mortality, we used Affymtrix 6.0 SNP arrays to examine paired DNA from peripheral blood and tumor cell populations isolated by laser capture microdissection to assess genome-wide loss of heterozygosity (LOH) and DNA copy number aberration (CNA) and their associations with risk factors, tumor characteristics, and oral cancer-specific mortality among 75 patients with HPV-negative OSCC. We found a highly heterogeneous and complex genomic landscape of HPV-negative tumors, and identified regions in 4q, 8p, 9p and 11q that seem to play an important role in oral cancer biology and survival from this disease. If confirmed, these findings could assist in designing personalized treatment or in the creation of models to predict survival in patients with HPV-negative OSCC.

Targeting cyclin-dependent kinases in human cancers: from small molecules to Peptide inhibitors

Cyclin-dependent kinases (CDK/Cyclins) form a family of heterodimeric kinases that play central roles in regulation of cell cycle progression, transcription and other major biological processes including neuronal differentiation and metabolism. Constitutive or deregulated hyperactivity of these kinases due to amplification, overexpression or mutation of cyclins or CDK, contributes to proliferation of cancer cells, and aberrant activity of these kinases has been reported in a wide variety of human cancers. These kinases therefore constitute biomarkers of proliferation and attractive pharmacological targets for development of anticancer therapeutics. The structural features of several of these kinases have been elucidated and their molecular mechanisms of regulation characterized in depth, providing clues for development of drugs and inhibitors to disrupt their function. However, like most other kinases, they constitute a challenging class of therapeutic targets due to their highly conserved structural features and ATP-binding pocket. Notwithstanding, several classes of inhibitors have been discovered from natural sources, and small molecule derivatives have been synthesized through rational, structure-guided approaches or identified in high throughput screens. The larger part of these inhibitors target ATP pockets, but a growing number of peptides targeting protein/protein interfaces are being proposed, and a small number of compounds targeting allosteric sites have been reported.

Multi-tiered genomic analysis of head and neck cancer ties TP53 mutation to 3p loss

Head and neck squamous cell carcinoma (HNSCC) is characterized by aggressive behavior with a propensity for metastasis and recurrence. Here we report a comprehensive analysis of the molecular and clinical features of HNSCC that govern patient survival. We find that TP53 mutation is frequently accompanied by loss of chromosome 3p, and that the combination of both events associates with a surprising decrease in survival rates (1.9 years versus >5 years for TP53 mutation alone). The TP53-3p interaction is specific to chromosome 3p, rather than a consequence of global genome instability, and validates in HNSCC and pan-cancer cohorts. In Human Papilloma Virus positive (HPV+) tumors, in which HPV inactivates TP53, 3p deletion is also common and associates with poor outcomes. The TP53-3p event is modified by mir-548k expression which decreases survival even further, while it is mutually exclusive with mutations to RAS signaling. Together, the identified markers underscore the molecular heterogeneity of HNSCC and enable a new multi-tiered classification of this disease.

Prognostic significance of TMEM16A, PPFIA1, and FADD expression in invasive ductal carcinoma of the breast

Background

11q13 region is a frequently amplified locus in human malignancies. Among the genes located in this region, FADD is one of the alleged driving genes. Because amplification is not generally confined to a single gene and amplified genes may not show increased expression, we need to evaluate clinical significance of changes occurring in 11q13 region to understand their roles in carcinogenesis. Therefore, we screened expressions of FADD and closely located genes (PPFIA1 and TMEM16A) and evaluated the expressions to find clinical significance in invasive ductal carcinoma of the breast.

Methods

Ninety-eight cases of invasive ductal carcinoma of the breast were collected. Using archival tissues resected from the cases, we built a tissue microarray and used it in immunohistochemistry. We evaluated the association of FADD, PPFIA1, and TMEM16A expression scores with clinicopathological parameters, including disease-free survival.

Results

FADD expression was associated with T stage (P = 0.046). The combined score of FADD, PPFIA1, and TMEM16A gene expressions was associated with perineural invasion (P = 0.022). Although individual gene expressions of TMEM16A, FADD, and PPFIA1 failed to show significant association with disease-free survival, combined gene expression scores did show association with disease-free survival (P = 0.034).

Conclusions

FADD, TMEM16A, and PPFIA1 gene expressions as a whole were associated with disease-free survival in breast cancer.

Cortactin, another player in the Lyn signaling pathway, is over-expressed and alternatively spliced in leukemic cells from patients with B-cell chronic lymphocytic leukemia

Cortactin, an actin binding protein and Lyn substrate, is up-regulated in several cancers and its level is associated with increased cell migration, metastasis and poor prognosis. The identification that the Src kinase Lyn and its substrate HS1 are over-expressed in B-cell chronic lymphocytic leukemia and involved in resistance to chemotherapy and poor prognosis, prompted us to investigate the role of cortactin, an HS1 homolog, in the pathogenesis and progression of this disorder. In this study, we observed that cortactin is over-expressed in leukemic cells of patients (1.10 ± 0.12) with respect to normal B lymphocytes (0.19 ± 0.06; P=0.0065). Fifty-three percent of our patients expressed the WT mRNA and p80/85 protein isoforms, usually lacking in normal B lymphocytes which express the SV1 variant and the p70/75 protein isoforms. Moreover, we found an association of the cortactin overexpression and negative prognostic factors, including ZAP-70 (P<0.01), CD38 (P<0.01) and somatic hypermutations in the immunoglobulin heavy-chain variable region (P<0.01). Our results show that patients with B-cell chronic lymphocytic leukemia express high levels of cortactin with a particular overexpression of the WT isoform that is lacking in normal B cells, and a correlation to poor prognosis, suggesting that this protein could be relevant in the pathogenesis and aggressiveness of the disease.

Heterogeneity of 11q13 region rearrangements in laryngeal squamous cell carcinoma analyzed by microarray platforms and fluorescence in situ hybridization

We reinvestigated rearrangements occurring in region q13 of chromosome 11 aiming to: (i) describe heterogeneity of the observed structural alterations, (ii) estimate amplicon size and (iii) identify of oncogenes involved in laryngeal cancer progression as potential targets for therapy. The study included 17 cell lines derived from laryngeal cancers and 34 specimens from primary laryngeal tumors. The region 11q13 was analyzed by fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH) and gene expression microarray. Next, quantitative real time PCR was used for chosen genes to confirm results from aCGH and gene expression microarray. The observed pattern of aberrations allows to distinguish three ways, in which gain and amplification involving 11q13 region may occur: formation of a homogeneously staining region; breakpoints in/near 11q13, which lead to the three to sevenfold increase of the copy number of 11q13 region; the presence of additional copies of the whole chromosome 11. The minimal altered region of gain and/or amplification was limited to ~1.8 Mb (chr.11:69,395,184-71,209,568) and comprised mostly 11q13.3 band which contain 12 genes. Five, out of these genes (CCND1, ORAOV1, FADD, PPFIA1, CTTN) had higher expression levels in comparison to healthy controls. Apart from CCND1 gene, which has an established role in pathogenesis of head and neck cancers, CTTN, ORAOV1 and FADD genes appear to be oncogene-candidates in laryngeal cancers, while a function of PPFIA1 requires further studies.

Impact of genetic targets on therapy in head and neck squamous cell carcinoma

Despite advances in surgical technique, radiation therapy and chemotherapy, the mortality from head and neck squamous cell carcinoma (HNSCC) has not improved significantly. Squamous cell carcinoma is caused by tobacco use, alcohol consumption and infection with high-risk types of human papillomavirus. It is the 6th most common cancer in the world, with upwards of 45,000 new cases reported yearly in the United States alone.In recent years, there has been a significant increase in the understanding of the molecular and genetic pathogenesis of head and neck cancer, shedding light on the unexpected heterogeneity of the disease. Genetic analysis has led to new classification schemes for HNSCC, with different subgroups exhibiting different prognoses. In addition, multiple targets in aberrant signaling pathways have been identified using increasingly sophisticated bio-informatics tools. Advances in technology have allowed for novel delivery mechanisms to introduce genetic material into cells to produce a therapeutic effect by targeting cancer cells via a number of different approaches.A pressing need to develop novel therapies to augment current treatment modalities has led to a number of translational studies involving gene therapy in the treatment of HNSCC. This article will focus on a review of the most recent developments in molecular biology of head and neck squamous cell carcinoma in regards to possible targets for gene therapy, as well as the array of novel therapeutic strategies directed at these targets.

Cyclin D1-a prognostic marker in oropharyngeal squamous cell carcinoma that is tightly associated with high-risk human papillomavirus status

Human papillomavirus-related oropharyngeal squamous cell carcinoma has a unique biology and improved prognosis. A new focus is to identify prognostic biomarkers specifically in this human papillomavirus-positive cohort. We analyzed cyclin D1 immunostaining on a tissue microarray of patients with known clinical follow-up and p16 and human papillomavirus status (by E6/E7 RNA in situ hybridization). Cyclin D1 staining was read visually and digitally. Cutoffs of 5%, 10%, and 30% were separately analyzed as was linear intensity data derived from the image analysis. For the 202 tumors, cyclin D1 expression was > 10% in 25.7% (visual) and 35.5% (digital) of the cases. It was > 30% in 15.8% (visual) and 16.5% (digital) of the cases. High cyclin D1 by both methods, cutoffs, and expression intensity was associated with poorer overall, disease-free, and disease-specific survival in univariate analysis. However, low cyclin D1 expression was also tightly associated with human papillomavirus RNA (P < 1.0 × 10(-18) for all cutoffs) and p16 positivity (P < 1.0 × 10(-14) for all cutoffs). In multivariate analysis using the digital 30% cutoff (the strongest cyclin D1 assessment method), only T stage, p16 status, smoking, and treatment approach associated with survival. Intensity of cyclin D1 expression did, however, significantly substratify the human papillomavirus RNA-positive patients into prognostic subgroups independent of other variables. In summary, cyclin D1 overexpression correlates strongly with patient survival in oropharyngeal squamous cell carcinoma, but its relationship with human papillomavirus status is very tight, and the complex nature of this correlation likely limits any clinical application for cyclin D1 assessment.

Prognostic implications of micoRNA miR-195 expression in human tongue squamous cell carcinoma

Background

miR-195 is aberrantly expressed in multiple types of disease. But little is known about the dysregulation of miR-195 in tongue squamous cell carcinoma (TSCC). In this study, we investigated the roles of miR-195 in the development and progression of TSCC.

Methods

Using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), we evaluated miR-195 expression in TSCC samples from 81 patients. Overall survival of these patients was examined using Kaplan–Meier curves with log-rank tests and the Cox proportional hazards model. The expression of two known miR-195 target genes, Cyclin D1 and Bcl-2, was also examined in the TSCC samples by immunohistochemistry. The effects of miR-195 overexpression on cell cycle progression and apoptosis and its effects on the expression of Cyclin D1 and Bcl-2 were examined in transfected TSCC cell lines (SCC-15 and Cal27) using fluorescence-activated cell sorting assays, luciferase reporter assays, and Western blots.

Results

Reduced miR-195 expression was associated with tumor size and the clinical stage of TSCC tumors. Kaplan–Meier survival analysis indicated that the TSCC patients with reduced expression of miR-195 had poor overall survival and in multivariable analyses low levels of miR-195 emerged as an independent prognostic factor for this clinical outcome. Levels of miR-195 expression were inversely correlated with the expression of Cyclin D1 and Bcl-2. Overexpression of miR-195 inhibited cell cycle progression, promoted apoptosis, and reduced Cyclin D1 and Bcl-2 expression in two TSCC cell lines.

Conclusions

miR-195 may have potential applications as a prognostic factor for TSCC patients.

Regulation of protein kinase C inactivation by Fas-associated protein with death domain

Protein kinase C (PKC) plays important roles in diverse cellular processes. PKC has been implicated in regulating Fas-associated protein with death domain (FADD), an important adaptor protein involved in regulating death receptor-mediated apoptosis. FADD also plays an important role in non-apoptosis processes. The functional interaction of PKC and FADD in non-apoptotic processes has not been examined. In this study, we show that FADD is involved in maintaining the phosphorylation of the turn motif and hydrophobic motif in the activated conventional PKC (cPKC). A phosphoryl-mimicking mutation (S191D) in FADD (FADD-D) abolished the function of FADD in the facilitation of the turn motif and hydrophobic motif dephosphorylation of cPKC, suggesting that phosphorylation of Ser-191 negatively regulates FADD. We show that FADD interacts with PP2A, which is a major phosphatase involved in dephosphorylation of activated cPKC and FADD deficiency abolished PP2A mediated dephosphorylation of cPKC. We show that FADD deficiency leads to increased stability and activity of cPKC, which, in turn, promotes cytoskeleton reorganization, cell motility, and chemotaxis. Collectively, these results reveal a novel function of FADD in a non-apoptotic process by modulating cPKC dephosphorylation, stability, and signaling termination.

Cortactin and focal adhesion kinase as predictors of cancer risk in patients with laryngeal premalignancy

Novel markers are needed to accurately predict the risk of malignant transformation in laryngeal premalignancies. We therefore investigated the clinical significance of cortactin (CTTN) and focal adhesion kinase (FAK) during laryngeal tumorigenesis and their potential utility as cancer risk markers. CTTN and FAK protein expression and gene amplification were assessed in 82 patients with laryngeal dysplasia and correlated with clinicopathologic parameters and laryngeal cancer risk. Increased CTTN and FAK expression was found respectively in 41 (50%) and 40 (49%) of 82 laryngeal dysplasias; protein expression was maintained or further augmented in the corresponding patient-matched invasive tumors subsequently developed. CTTN and FAK/PTK2 gene amplifications were respectively detected in 10 (12%) and 26 (32%) laryngeal dysplasias. Both CTTN and FAK protein expression increased with the grade of dysplasia; however, CTTN and FAK expression but not histology correlated significantly with increased laryngeal cancer risk (P = 0.009 and P = 0.002, respectively). Patients carrying strong CTTN- or FAK-expressing dysplastic lesions experienced a significantly higher cancer incidence (P = 0.006 and P = 0.001, respectively; log-rank test). Furthermore, FAK expression was an independent predictor of laryngeal cancer development (HR = 3.706, 95% CI: 1.735-7.916; P = 0.001) and the combination of FAK and CTTN showed superior predictive value (HR = 5.042, 95% CI: 2.255-11.274; P < 0.001). Taken together, our findings support the involvement of CTTN and FAK in malignant transformation and provide original evidence for their potential clinical utility as biomarkers for the risk of developing laryngeal cancer.

ORAOV1 is amplified in oral squamous cell carcinoma

BACKGROUND

Oral cancer overexpressed 1 (ORAOV1) was found as a candidate oncogene in the 11q13 chromosomal region, based on its amplification and overexpression in oral cancer cell lines. Because gene amplification often leads to increased levels of gene expression, we aimed to verify the relationship between ORAOV1 gene status and mRNA expression primarily in oral squamous cell carcinoma (OSCC) by quantitative assay, correlating with clinical and pathological characteristics in patients.

METHODS

Levels of ORAOV1 amplification and expression were evaluated by qPCR and RT-qPCR in OSCC cell lines and in tumor and non-tumoral surgical margins from 33 patients with OSCC. All subjects were smokers and habitual alcohol drinkers, mostly men above 40 years of age and with a single primary tumor.

RESULTS

ORAOV1 exhibited increased gene expression levels as well as higher copy number in three OSCC cell lines with 11q13 amplified chromosomal region when compared with the OSCC cell line without the amplification (one-way ANOVA, P < 0.05). Weak correlation between ORAOV1 mRNA levels and DNA copy number was seen in tumor samples (Spearman, P = 0.07). Although ORAOV1 was amplified in tumor (Wilcoxon, P < 0.01), high levels of transcripts in margin did not reveal differences in comparison with tumor (Wilcoxon, P = 0.85). Aggressiveness and survival rate did not demonstrate statistical difference for both events in OSCC.

CONCLUSION

The overexpression of ORAOV1 in non-tumoral margin samples can occur in the absence of amplification. The weak correlation between ORAOV1 amplification and expression in OSSC suggests that ORAOV1 expression can be regulated by mechanisms other than gene amplification.

Recently identified biomarkers that promote lymph node metastasis in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous cancer that arises in the upper aerodigestive tract. Despite advances in knowledge and treatment of this disease, the five-year survival rate after diagnosis of advanced (stage 3 and 4) HNSCC remains approximately 50%. One reason for the large degree of mortality associated with late stage HNSCC is the intrinsic ability of tumor cells to undergo locoregional invasion. Lymph nodes in the cervical region are the primary sites of metastasis for HNSCC, occurring before the formation of distant metastases. The presence of lymph node metastases is strongly associated with poor patient outcome, resulting in increased consideration being given to the development and implementation of anti-invasive strategies. In this review, we focus on select proteins that have been recently identified as promoters of lymph node metastasis in HNSCC. The discussed proteins are involved in a wide range of critical cellular functions, and offer a more comprehensive understanding of the factors involved in HNSCC metastasis while additionally providing increased options for consideration in the design of future therapeutic intervention strategies.

Overexpression of cortactin increases invasion potential in oral squamous cell carcinoma

Cortactin, an F-actin binding protein, stabilizes F-actin networks and promotes actin polymerization by activating the Arp2/3 complex. Overexpression of cortactin has been reported in several human cancers. Cortactin stimulates cell migration, invasion, and experimental metastasis. However, the underlying mechanism is not still understood. In the present study, we therefore evaluated the possibility that cortactin could be appropriate as a molecular target for cancer gene therapy. In 70 primary oral squamous cell carcinomas and 10 normal oral mucosal specimens, cortactin expression was evaluated by immunological analyses, and the correlations of the overexpression of cortactin with clinicopathologic factors were evaluated. Overexpression of cortactin was detected in 32 of 70 oral squamous cell carcinomas; significantly more frequently than in normal oral mucosa. Cortactin overexpression was more frequent in higher grade cancers according to T classification, N classifications, and invasive pattern. Moreover, RNAi-mediated decrease in cortactin expression reduced invasion. Downregulation of cortactin expression increased the expression levels of E-cadherin, β-catenin, and EpCAM. The siRNA of cortactin also reduced PTHrP expression via EGF signaling. These results consistently indicate that the overexpression of cortactin is strongly associated with an aggressive phenotype of oral squamous cell carcinoma. In conclusion, we propose that cortactin could be a potential molecular target of gene therapy by RNAi targeting in oral squamous cell carcinoma.

Cyclin D1 overexpression increases susceptibility to 4-nitroquinoline-1-oxide-induced dysplasia and neoplasia in murine squamous oral epithelium

The cyclin D1 oncogene is frequently amplified/overexpressed in oral squamous cell carcinomas. Mice with overexpression of cyclin D1 targeted to the stratified squamous epithelia of the tongue, esophagus, and forestomach develop a phenotype of epithelial dysplasia at these sites. In this study, we examined the effect of cyclin D1 overexpression on susceptibility of mice to carcinogen-induced tumorigenesis, using 4-nitroquinoline-1-oxide (4NQO), an established potent oral carcinogen in mice. Cyclin D1 overexpressing mice and nontransgenic littermates were administered 4NQO (20 or 50 parts per million (ppm) in the drinking water) for 8 wk and monitored for an additional 16 wk. Histopathological analyses of the tongue revealed significantly higher severity of dysplasia in the cyclin D1 overexpression mice, compared with nontransgenic controls and with untreated controls. Moreover, only the cyclin D1 overexpression mice developed neoplastic lesions in the oro-esophageal epithelia. Examination of the dysplastic and neoplastic lesions revealed abnormal proliferation. Our findings suggest that cyclin D1 overexpression enhances susceptibility to carcinogen-induced oral tumorigenesis. These results underscore the importance of cyclin D1 in the process of oral neoplastic development. Further, they emphasize the value of this transgenic model to study the pathogenesis of oral precancer and cancer and establish it as a model system to test candidate agents for chemoprevention of upper aero-digestive cancer.

The galanin signaling cascade is a candidate pathway regulating oncogenesis in human squamous cell carcinoma

To identify putative biomarkers in squamous cell carcinoma (SCC), a survey of parallel chromosomal alterations and gene expression studies in 10 SCC cell lines were performed using array-comparative genomic hybridization (CGH) and oligo-microarray techniques. The most frequent changes were gains of 11q13.1-13.3 and losses of 18q12.1-23 in SCC. Furthermore, the expression levels of the sets of genes at both these loci in SCC were measured using microarray analysis. By combining the array-CGH with the microarray data, 10 genes at 11q13.1-13.3 and 6 genes at 18q12.1-23 whose expression correlated with chromosomal alterations were identified. To verify the expression levels of the identified genes, we used expression analysis data derived from our earlier study of clinical specimens. In clinical samples, six genes (GAL, GSTP1, MRPL11, MRPL21, SF3B2, and YIF1A) at 11q13.1-13.3 and one gene (GALR1) at 18q23 showed a significant difference between normal and tumor samples. GAL, coding for the neuropeptide galanin, and GALR1, a galanin receptor, were identified as candidate genes of oncogenesis in SCC. The expression levels of GAL, GALR1, GALR2, and GALR3 were confirmed by real-time PCR. The expression ratio between GAL and GALR1 showed a significant negative correlation. GALR1 is a G-protein-coupled receptor that activates GTP-binding proteins to trigger signaling cascades such as the mitogen-activated protein kinase pathway, and is a well-established mitogenic pathway. This further supports the hypothesis that the genes involved in the GAL signaling cascade are candidates for regulation of oncogenesis in SCC.

Distinctive clinicopathological associations of amplification of the cortactin gene at 11q13 in head and neck squamous cell carcinomas

Amplification of the 11q13 region is a prevalent genetic alteration in head and neck squamous cell carcinoma (HNSCC). We investigated the clinical significance of cortactin (CTTN) and cyclin D1 (CCND1) amplification in both malignant transformation and tumour progression. CTTN and CCND1 amplification was analysed by differential and real-time PCR in a prospective series of laryngeal/pharyngeal carcinomas and archival premalignant tissues. CTTN mRNA and protein expression were respectively determined by real-time RT-PCR and immunohistochemistry, and correlated with gene status. Molecular alterations were associated with clinicopathological parameters and disease outcome. CTTN and CCND1 amplifications were respectively found in 75 (37%) and 90 (45%) tumours. Both correlated with advanced disease; however, only CTTN amplification was associated with recurrence and reduced disease-specific survival (p = 0.0022). Strikingly, CTTN amplification differentially influenced survival depending on tumour site (p = 0.0001 larynx versus p = 0.68 pharynx) and was an independent predictor of reduced survival in the larynx (p = 0.04). CCND1 amplification was detected in early tumourigenesis and increased with the severity of dysplasia. Importantly, CTTN amplification was only found in high-grade dysplasias that progressed to invasive carcinoma. CTTN gene status strongly correlated with mRNA and protein expression. Furthermore, CTTN overexpression correlated significantly with reduced disease-specific survival (p = 0.018). Taken together, these data indicate that CTTN may serve as a valuable biomarker to identify patients with laryngeal tumours at high risk of recurrence and poor outcome.

DNA copy number variation and loss of heterozygosity in relation to recurrence of and survival from head and neck squamous cell carcinoma: a review

Genetic aberrations, such as DNA copy number variation (CNV) and loss of heterozygosity (LOH), have been implicated in head and neck squamous cell carcinoma (HNSCC) initiation and progression. This review examines CNV and LOH as predictors of HNSCC recurrence and mortality. We searched PubMed for relevant publications and compared and discussed results from the articles. Certain CNV and LOH events have consistently been associated with HNSCC recurrence and survival. The recent high-resolution single nucleotide polymorphism (SNP) arrays have the potential to identify many more genetic changes and concurrent genome-wide CNV, copy-neutral and/or allelic imbalance LOH in HNSCC that may bear on prognosis. Our review confirms that outcome in HNSCC can be predicted to a considerable extent by the presence of tumor cell genetic aberrations. It points out the limitations of some methodologies that were used in the past and discusses the advantages and challenges of using genome-wide SNP arrays.

Aggressiveness of HNSCC tumors depends on expression levels of cortactin, a gene in the 11q13 amplicon

11q13 amplification is a late-stage event in several cancers that is often associated with poor prognosis. Among 11q13-amplified genes, the actin assembly protein cortactin/CTTN is considered a likely candidate for direct involvement in tumor progression, because of its cell motility-enhancing functions. We modulated cortactin expression in head and neck squamous cell carcinoma (HNSCC) lines. Cortactin expression levels directly correlated with tumor size, vascularization, and cell proliferation in an orthotopic HNSCC in vivo model. In contrast, under normal in vitro culture conditions, cortactin expression levels had no effect on cell proliferation. However, cell lines in which cortactin expression was reduced by knockdown (KD) grew poorly in vitro under harsh conditions of growth-factor deprivation, anchorage independence, and space constraint. Conversely, overexpression of cortactin enhanced in vitro growth under the same harsh conditions. Surprisingly, defects in growth factor-independent proliferation of cortactin-KD cells were rescued by co-culture with cortactin-expressing cells. Since the co-cultured cells are separated by permeable filters, cortactin-expressing cells must secrete growth-supporting autocrine factors to rescue the cortactin-KD cells. Overall, cortactin expression modulates multiple cellular traits that may allow survival in a tumor environment, suggesting that the frequent overexpression of cortactin in tumors is not an epiphenomenon but rather promotes tumor aggressiveness.

Genetic profile of head and neck squamous cell carcinoma: clinical implications

The outcome for patients with head and neck squamous cell carcinoma remains poor, despite improvements in diagnosis and treatment over the past three decades. This has triggered great interest in the genetic events that underpin the aetiology and clinical behaviour of this group of cancers. As a result, the genetic profile for head and neck squamous cell carcinomas at different sub-sites has been relatively well characterised at the chromosomal level. Various studies have shown links between specific aberrations in head and neck squamous cell carcinoma and clinical outcome, e.g. loss of heterozygosity at 2q and 18q is commonly associated with poor prognosis, and loss of heterozygosity at 9p21 is associated with recurrence. However, there is as yet no significant clinical application of this genetic knowledge as regards the screening, diagnosis or treatment of head and neck squamous cell carcinoma. Here, we summarise the current state of knowledge, and highlight the most promising areas of research that may facilitate the translation of genetic data into clinical benefit.

Cortactin in tumor invasiveness

Cortactin is a cytoskeletal protein and src kinase substrate that is frequently overexpressed in cancer. Animal studies suggest that cortactin overexpression increases tumor aggressiveness, possibly through promotion of tumor invasion and metastasis. Recently, many studies have documented a role for cortactin in promoting cell motility and invasion, including a critical role in invadopodia, actin rich-subcellular protrusions associated with degradation of the extracellular matrix by cancer cells. Here, I review the evidence and potential mechanisms for cortactin as a critical mediator of tumor cell invasion.

Amplification and overexpression of PPFIA1, a putative 11q13 invasion suppressor gene, in head and neck squamous cell carcinoma

Chromosomal amplifications of the 11q13 genomic region are frequent in head and neck squamous cell carcinoma (HNSCC). To identify novel 11q13 amplification targets, we integrated high-resolution array-based comparative genomic hybridization and Affymetrix gene-expression profiling of eight HNSCC cell lines. We found that PPFIA1 was the highest upregulated gene in the 11q13 amplicon of HNSCC cell lines when compared with HNSCC lines without 11q13 amplification and confirmed the upregulation of PPFIA1 in primary HNSCCs by real-time PCR. Using siRNA knockdown, we investigated PPFIA1 function in three HNSCC lines using both in vitro invasion assays and wound-healing assays. Surprisingly, we found that cancer cells become more invasive when the PPFIA1 protein levels were reduced, suggesting that PPFIA1 may act as an invasion inhibitor in HNSCC. This unexpected result suggests that the 11q13 amplicon may comprise both positive and negative regulators involved in HNSCC. Our study is the first to evaluate the role of PPFIA1 in head and neck carcinogenesis and suggests a potential link between PPFIA1 activity and cell-extracellular matrix interactions. This article contains supplementary material available via the Internet at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.

Cortactin expression predicts poor survival in laryngeal carcinoma

Amplification of the 11q13 region is one of the most frequent aberrations in squamous cell carcinomas of the head and neck region (HNSCC). Amplification of 11q13 has been shown to correlate with the presence of lymph node metastases and decreased survival. The 11q13.3 amplicon carries numerous genes including cyclin D1 and cortactin. Recently, we reported that FADD becomes overexpressed upon amplification and that FADD protein expression predicts for lymph node positivity and disease-specific mortality. However, the gene within the 11q13.3 amplicon responsible for this correlation is yet to be identified. In this paper, we compared, using immunohistochemical analysis for cyclin D1, FADD and cortactin in a series of 106 laryngeal carcinomas which gene correlates best with lymph node metastases and increased disease-specific mortality. Univariate Cox regression analysis revealed that high expression of cyclin D1 (P=0.016), FADD (P=0.003) and cortactin (P=0.0006) predict for increased risk to disease-specific mortality. Multivariate Cox analysis revealed that only high cortactin expression correlates with disease-specific mortality independent of cyclin D1 and/or FADD. Of genes located in the 11q13 amplicon, cortactin expression is the best predictor for shorter disease-specific survival in late stage laryngeal carcinomas.

Head and neck squamous cell carcinoma cell lines: established models and rationale for selection

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) cell lines are important preclinical models in the search for novel and targeted therapies to treat head and neck cancer. Unlike many other cancer types, a wide variety of primary and metastatic HNSCC cell lines are available. An easily accessible guide that organizes important characteristics of HNSCC cell lines would be valuable for the selection of appropriate HNSCC cell lines for in vitro or in vivo studies.

METHODS

A literature search was performed.

RESULTS

Cell growth and culture parameters from HNSCC cell lines were catalogued into tables or lists of selected characteristics. Methods for establishing cancer cell lines and basic cell culture maintenance techniques were reviewed.

CONCLUSIONS

A compendium of HNSCC cell line characteristics is useful for organizing the accumulating information regarding cell line characteristics to assist investigators with the development of appropriate preclinical models.

Molecular cytogenetic characterization of the 11q13 amplicon in head and neck squamous cell carcinoma

Amplification of 11q13 DNA sequences and overexpression of CCND1 are common findings in head and neck squamous cell carcinoma (HNSCC), identified in about 30% of the cases. However, little is known about initiation of the amplification and the organization of the amplicon. In order to study the structure of the amplicon in more detail and to learn more about the mechanisms involved in its initiation, prometaphase, metaphase, and anaphase fluorescence in situ hybridization (FISH) with 40 BAC clones spanning a 16-Mb region in chromosome bands 11q12.2 to 11q13.5 was performed in nine HNSCC cell lines with homogeneously staining regions. FISH analysis showed that the size of the amplicon varied among the nine cell lines, the smallest being 2.12 Mb and the largest 8.97 Mb. The smallest overlapping region of amplification was approximately 1.61 Mb, covering the region from BAC 729E14 to BAC 102B19. This region contained several genes previously shown to be amplified and overexpressed in HNSCC, including CCDN1, CTTN, SHANK2, and ORAOV1. The cell lines were also used to study the internal structure of the amplicon. Various patterns of amplified DNA sequences within the amplicon were found among the nine cell lines. Even within the same cell line, different amplicon structures could be found in different cell populations, indicating that the mechanisms involved in the development of the amplicons in HNSCC were more complex than previously assumed. The frequent finding of inverted repeats within the amplicons, however, suggests that breakage-fusion-bridge cycles are important in the initiation, but the fact that such repeats constituted only small parts of the amplicons indicate that they are further rearranged during tumor progression.

Amplifications of TAOS1 and EMS1 genes in oral carcinogenesis: association with clinicopathological features

Amplification of chromosomal region 11q13 is one of the genetic alterations most frequently observed in oral squamous cell carcinoma (OSCC). Both TAOS1, a recently identified gene, and EMS1 were thought as two important target oncogenes for driving 11q13 amplification, and their contributions to oral carcinogenesis were hypothesized. Therefore we investigated amplifications of TAOS1 and EMS1 genes and their relations to clinicopathological variables in premalignant lesions (leukoplakias) and primary OSCC. TAOS1 amplification, beginning from mild-dysplastic epithelia, occurred in 33.3% of leukoplakias and 51.5% of OSCC. EMS1 amplification, beginning from moderate-dysplastic epithelia, occurred in 20% of leukoplakias and 57.6% of OSCC. Both gene amplifications were significantly related to different stages of oral carcinogenesis (p<0.05). During multistage carcinogenesis, no gene amplification was observed in normal tissue and non-dysplastic leukoplakias while, in OSCC with metastasis, amplification frequency increased significantly (p<0.005). Both TAOS1 and EMS1 amplifications were significantly associated with larger tumor size, presence of lymph node metastasis, poor histological differentiation and advanced clinical stage. Our data suggested potential roles in oral carcinogenesis and that TAOS1 might be involved earlier than EMS1. Both genes might be candidate biomarkers for diagnosis and prognosis in OSCC.

Molecular biology of squamous cell carcinoma of the head and neck

Squamous cell carcinoma of the head and neck (HNSCC) is a heterogeneous but largely preventable disease with complex molecular abnormalities. It arises from a premalignant progenitor followed by outgrowth of clonal populations associated with cumulative genetic alterations and phenotypic progression to invasive malignancy. These genetic alterations result in inactivation of multiple tumour suppressor genes and activation of proto-oncogenes, including p16(ink4A), p53, cyclin D1, p14(ARF), FHIT, RASSF1A, epidermal growth factor receptor (EGFR), and Rb. Intramucosal migration and clonal expansion of transformed cells with formation of abnormal genetic fields appear to be responsible for local recurrences and development of second primary tumours.

Prevention of head and neck cancer

In the vast majority of cases, head and neck cancer is a preventable disease. The relationship between tobacco and alcohol and these cancers is well established. Despite efforts aimed at reduction of risk factor exposure and early detection methods, head and neck cancer remains one of the more common cancers worldwide. Recent advances in molecular techniques have provided a framework for future targets for early diagnosis and treatment of these malignancies. This review provides a summary of recent developments in primary and secondary prevention of head and neck cancer and innovative strategies aimed at a reduction in incidence and mortality from this disease. The future prevention of head and neck cancer will likely require solutions to the widespread use of tobacco products and innovative diagnostic techniques leading to improvements in overall survival.

Cyclin D1 gene numerical aberration is a predictive marker for occult cervical lymph node metastasis in TNM Stage I and II squamous cell carcinoma of the oral cavity

BACKGROUND

The management of occult cervical lymph node metastases originating from oral squamous cell carcinomas (OSCCs) remains controversial. The purpose of this study was to evaluate the value of cyclin D1 gene (CCND1) numerical aberrations in predicting the risk of late lymph node metastases.

METHODS

Fluorescence in situ hybridization (FISH), using a BAC clone specific for CCND1, was performed on OSCC specimens obtained by fine-needle aspiration (FNA) biopsy from 45 patients with previously untreated TNM Stage I and II (T1-2N0M0) disease who had not undergone elective cervical lymph node dissection.

RESULTS

CCND1 numerical aberrations were observed in 15 (33.3%) of the 45 patients and were significantly associated with the mode of invasion of the primary tumor (P = 0.01) and the presence of occult lymph node metastases (P < 0.001). Twelve of these 15 patients (80%) developed late cervical lymph node metastases within 2 years of surgery for primary OSCCs. All patients with cluster-type amplification of CCND1 developed late lymph node metastases. Multivariate analysis showed that only CCND1 numerical aberrations (risk ratio, 8.685%, 95% confidence interval = 2.232-33.802, P = 0.002) independently predicted late cervical lymph node metastasis.

CONCLUSIONS

Aberrations in CCND1 numbers appear to be valuable in identifying patients at high risk of late lymph node metastasis in Stage I and II OSCCs. Analysis of CCND1 numerical aberrations using FISH on FNA biopsy specimens may be useful in selecting patients for elective cervical lymph node dissection.

Dominant expression of 85-kDa form of cortactin in colorectal cancer

PURPOSE

Cortactin is commonly expressed in several human cancers, which may alter their invasive or metastatic properties. Eighty five kilodalton form (p85) and 80-kDa form (p80) of cortactin are two separate bands in SDS-PAGE representing different conformational states. The objective of this study was to investigate cortactin expression in colorectal cancer (CRC).

EXPERIMENTAL DESIGN

Cortactin expression was studied in an eight paired laser capture microdissection (LCM) CRC tissues and matched non-cancerous epithelia by immunoblotting. The expression in 58 CRC and two cell lines, HCT8 and HCT116, was studied respectively by immunohistochemistry and confocal laser scanning immunofluorescence.

RESULTS

Dominant expression of p85 was identified in LCM-procured CRC tissues compared with equal intensity of p85 and p80 forms in non-cancerous tissues, while the amount of total cortactin was approximate. Immunohistochemistry analysis demonstrated that cortactin located in the cytoplasm of tumor cells and adjacent non-cancerous cells, and its expression was negatively correlated with TNM staging and lymphatic invasion status. However, the invasion fronts in 3 of 58 primary tumors and 28 of 39 available lymph node metastases were intensively stained. Further, immunofluorescence analysis showed that cortactin was distributed in cytoplasm and enriched in the front of the extending lamellipodia at adhering side of cultured cancer cells.

CONCLUSIONS

Our results demonstrated the dominant expression of p85 form of cortactin in CRC for the first time. The enrichment of cortactin in the invasion front of some tumor cells and in the extending lamellipodia of cultured cancer cells suggests that cortactin may help cancer cell movement.

Genetic expression profiles and biologic pathway alterations in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is associated with considerable mortality and morbidity and is a major public health concern worldwide. To date, > 20 studies incorporating DNA microarray analyses have examined genomewide genetic expression changes associated with the development of HNSCC. The authors identified published reports of genetic expression profiles of HNSCC by Medline database search. They performed a review of the reports to identify genes that have been found repeatedly to exhibit substantially altered expression in HNSCC. Genes with altered expression were subsequently examined in the context of defined biologic systems with the use of GenMapp 2.0 pathway analysis software. Genes most commonly found to exhibit altered expression were those encoding for cytoskeletal and extracellular matrix proteins, inflammatory mediators, proteins involved in epidermal differentiation, and cell adhesion molecules. Results of GenMapp 2.0 analysis suggested global down-regulation of genes that encode for ribosomal proteins and enzymes in the cholesterol biosynthesis pathway; and up-regulation of genes that encode for matrix metalloproteinases and genes that bear on the inflammatory response. The review indicated that there are several genes and pathways that exhibit substantially altered expression in cancerous versus noncancerous states across studies. Further investigation into the genomic, proteomic, and functional consequences of these gene expression alterations may provide insight into the pathophysiology of HNSCC.

Aberrations of 11q13 in laryngeal squamous cell lines and their prognostic significance

Chromosomal aberrations were analyzed in 12 established cell lines derived from laryngeal squamous cell carcinoma. Cytogenetic and fluorescence in situ hybridization studies were used to identify aberrations in the 11q13 region and in some other chromosome regions. Amplification of 11q13 was established only in the cell lines derived from subjects with a survival period of less than 5 years and, together with the 3q gain, were the only chromosomal structural abnormalities connected with short survival. In this group we also found translocations with a breakpoint within 11q13. In three cell lines, 11q13 was observed as a homogenously staining region. The results suggest that amplification of 11q13, as well as re-arrangements potentially involved in up-regulation of the oncogenes mapped in 11q13, should be considered as markers of poor prognosis in laryngeal cancer. A diagnostic significance of 11q13 may be increased by a parallel determination with 3q gain.

Dietary garcinol inhibits 4-nitroquinoline 1-oxide-induced tongue carcinogenesis in rats

The effects of dietary feeding with a polyisoprenylated benzophenone, garcinol, isolated from Garcinia indica fruit rind on the development of 4-nitroquinoline 1-oxide (4-NQO)-induced oral carcinogenesis were investigated in male F344 rats. At 7 weeks of age, animals were given 4-NQO at 20 ppm in the drinking water for 8 weeks to induce tongue neoplasms. They also received the diets containing 100 or 500 ppm garcinol either during (for 10 weeks) or after (for 22 weeks) the carcinogen exposure. The other rats were given tap water without 4-NQO throughout the experiment, and fed garcinol (500 ppm)-containing diet or basal diet alone. At the end of the study (week 32), incidences of tongue neoplasms and preneoplastic lesions, cell proliferation activity in the normal-like tongue epithelium estimated by 5-bromodeoxyurideine (BrdU)-labeling index and cyclin D1-positive cell ratio, and immunohistochemical expression of cyclooxygenase-2 (COX-2) in the tongue lesions were determined. Dietary garcinol significantly decreased the incidence and multiplicity of 4-NQO-induced tongue neoplasms and/or preneoplasms as compared to the control diet. Dietary administration of garcinol also significantly reduced the BrdU-labeling index and cyclin D1-positive cell ratio, suggesting reduction in cell proliferation activity in the tongue by garcinol. The COX-2 expression in the tongue lesions was also suppressed by feeding with garcinol. These results indicate that dietary administration of garcinol inhibited 4-NQO-induced tongue carcinogenesis through suppression of increased cell proliferation activity in the target tissues and/or COX-2 expression in the tongue lesions.

Molecular introduction to head and neck cancer (HNSCC) carcinogenesis

Of all human cancers, HNSCC is the most distressing affecting pain, disfigurement, speech and the basic survival functions of breathing and swallowing. Mortality rates have not significantly changed in the last 40 years despite advances in radiotherapy and surgical treatment. Molecular markers are currently being identified that can determine prognosis preoperatively by routine tumour biopsy leading to improved management of HNSCC patients. The approach could help decide which early stage patient should have adjuvant neck dissection and radiotherapy, and whether later stage patients with operable lesions would benefit from resection and reconstructive surgery or adopt a conservative approach to patients with poor prognosis regardless of treatment. In the future, understanding these basic genetic changes in HNSCC would be important for the management of HNSCC.

Tissue Microarray Analysis of Cyclin D1 Gene Amplification and Gain in Colorectal Carcinomas

Colorectal cancer is one of the most common neoplastic diseases and one of the leading causes of cancer-related deaths. Elevated beta-catenin levels in colorectal cancer result in the binding of beta-catenin to LEF-1 and increased transcriptional activation of the CCND1 gene. Overexpression of cyclin D1 is observed in one third of colorectal tumors. CCND1 amplification is the main cause of protein overexpression in numerous human carcinomas. In colorectal cancer, however, no CCND1 amplification has been reported so far. The aim of this study was to determine the frequency of CCND1 amplifications and gains in a large number of colorectal carcinomas, arranged in a tissue microarray, in order to assess their role in colorectal cancer development. The copy number changes, detected by fluorescence in situ hybridization, were predominantly gains (7.6%) and only rarely amplifications (2.5%). In colorectal cancer, the CCND1 copy number increase was neither associated with the tumor phenotype (stage and grade) nor with the tumor localization (colon, rectum or sigmoid colon). In conclusion, even in a small number of colorectal tumors, CCND1 gene amplification is a possible mechanism for the increase in cyclin D1 oncoprotein.