Caveolin-1-negative head and neck squamous cell carcinoma primary tumors display increased epithelial to mesenchymal transition and prometastatic properties.

Distant metastases arise in 20-30% of patients with squamous cell carcinoma of the head and neck (HNSCC) in the 2 years following treatment. Therapeutic options are limited and the outcome of the patients is poor. The identification of predictive biomarkers of patient at risk for distant metastasis and therapies are urgently needed. We previously identified a clinical subgroup, called "R1" characterized by high propensity for rapid distant metastasis. Here, we showed that "R1" patients do not or at very low level express caveolin-1 (Cav1). Low or no expression of Cav1 is of bad prognosis. Disappearance of Cav1 enables cells to undergo epithelial-mesenchymal transition (EMT). EMT is associated with enhanced migration and invasion. Our study uncovered a new target, α5ß1 integrin. Targeting α5ß1 integrins might not only prevent metastasis of HNSCC but also delay the development of the primary tumor by reducing tumor cell viability. Cav1 detection might be taken into consideration in the future in the clinic not only to identify patients at high risk of metastasis but also to select patient who might benefit from an anti-integrin therapy.

Human Papillomavirus-related tumours of the oropharynx display a lower tumour hypoxia signature.

OBJECTIVES: Human Papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OSCC) patients have improved prognosis compared to other head and neck (HNSCC) cancers. Since poor prognosis is associated with tumour hypoxia, we studied whether the hypoxic response is different in HPV-related cells and tumours. MATERIAL AND METHODS: HPV-positive and -negative cells were incubated in hypoxia and analyzed by qRTPCR, western blotting and cell proliferation assays. Tumours formed by xenografting these cells in nude mice were studied by IHC. HNSCC patient samples were analyzed by unsupervised clustering of hypoxia-related gene expression, quantitative real-time PCR (qRTPCR) and immunohistochemical (IHC) detection of neo-blood vessels. RESULTS AND CONCLUSION: HPV-positive and -negative cells responded differently to hypoxia, in terms of gene expression (HIF-1α, PHD-3, GLUT-1 and VEGF-A) and cell survival. Tumour xenografts formed by HPV-positive cells had fewer hypoxic areas than those formed by HPV-negative cells. HPV related tumours were less hypoxic, expressed lower levels of hypoxia-responsive genes, and had a higher density of neo-blood vessels. HPV-related OSCC display lower tumour hypoxia, which could be linked to the distinct intrinsic abilities of HPV-positive tumour cells to adapt to hypoxia and to their better prognosis.

From ERα66 to ERα36: a generic method for validating a prognosis marker of breast tumor progression.

BACKGROUND: Estrogen receptor alpha36 (ERalpha36), a variant of estrogen receptor alpha (ER) is expressed in about half of breast tumors, independently of the [ER+]/[ER-] status. In vitro, ERalpha36 triggers mitogenic non-genomic signaling and migration ability in response to 17beta-estradiol and tamoxifen. In vivo, highly ERalpha36 expressing tumors are of poor outcome especially as [ER+] tumors are submitted to tamoxifen treatment which, in turn, enhances ERalpha36 expression. RESULTS: Our study aimed to validate ERalpha36 expression as a reliable prognostic factor for cancer progression from an estrogen dependent proliferative tumor toward an estrogen dispensable metastatic disease. In a retrospective study, we tried to decipher underlying mechanisms of cancer progression by using an original modeling of the relationships between ERalpha36, other estrogen and growth factor receptors and metastatic marker expression. Nonlinear correlation analyses and mutual information computations led to characterize a complex network connecting ERalpha36 to either non-genomic estrogen signaling or to metastatic process. CONCLUSIONS: This study identifies ERalpha36 expression level as a relevant classifier which should be taken into account for breast tumors clinical characterization and [ER+] tumor treatment orientation, using a generic approach for the rapid, cheap and relevant evaluation of any candidate gene expression as a predictor of a complex biological process.

Stimulation of breast cancer cell lines by post-surgical drainage fluids.

BACKGROUND/AIM: Surgery, which remains a conventional treatment of breast tumors, may induce the secretion of growth factors that support angiogenesis and wound healing. These factors are suspected to trigger carcinoma cell division and promote tumor relapse. We addressed this question by culturing breast cancer cell lines in the presence of wound fluid harvested after surgery. MATERIALS AND METHODS: Wound fluids were collected from patients who underwent either breast reconstruction, tumor resection, or tumor resection after neoadjuvant chemotherapy. MCF-7 (estrogen receptor (ER)+/progesterone receptor (PgR)+, HCC1937 (ER/PgR-, human epidermal growth factor receptor/neuralized (HER2/neu)-) and MCF-10A (used as a negative control) cell lines were grown in culture media supplemented with wound fluids. RESULTS: Wound fluids drained during the three categories of procedures significantly stimulated the proliferation of MCF-7 and HCC1937 cells in a similar manner. CONCLUSION: This stimulatory effect on tumor cell proliferation could be attenuated by therapeutic targeting against growth factors and inflammation processes in order to avoid tumor relapse.

A poor prognosis subtype of HNSCC is consistently observed across methylome, transcriptome, and miRNome analysis.

PURPOSE: Distant metastasis after treatment is observed in about 20% of squamous cell carcinoma of the head and neck (HNSCC). In the absence of any validated robust biomarker, patients at higher risk for metastasis cannot be provided with tailored therapy. To identify prognostic HNSCC molecular subgroups and potential biomarkers, we have conducted genome-wide integrated analysis of four omic sets of data. EXPERIMENTAL DESIGN: Using state-of-the-art technologies, a core set of 45 metastasizing and 55 nonmetastasizing human papillomavirus (HPV)-unrelated HNSCC patient samples were analyzed at four different levels: gene expression (transcriptome), DNA methylation (methylome), DNA copy number (genome), and microRNA (miRNA) expression (miRNome). Molecular subgroups were identified by a model-based clustering analysis. Their clinical relevance was evaluated by survival analysis, and functional significance by pathway enrichment analysis. RESULTS: Patient subgroups selected by transcriptome, methylome, or miRNome integrated analysis are associated with shorter metastasis-free survival (MFS). A common subgroup, R1, selected by all three omic approaches, is statistically more significantly associated with MFS than any of the single omic-selected subgroups. R1 and non-R1 samples display similar DNA copy number landscapes, but more frequent chromosomal aberrations are observed in the R1 cluster (especially loss at 13q14.2-3). R1 tumors are characterized by alterations of pathways involved in cell-cell adhesion, extracellular matrix (ECM), epithelial-to-mesenchymal transition (EMT), immune response, and apoptosis. CONCLUSIONS: Integration of data across several omic profiles leads to better selection of patients at higher risk, identification of relevant molecular pathways of metastasis, and potential to discover biomarkers and drug targets.

DDB2: a novel regulator of NF-κB and breast tumor invasion.

The DNA repair protein damaged DNA-binding 2 (DDB2) has been implicated in promoting cell-cycle progression by regulating gene expression. DDB2 is selectively overexpressed in breast tumor cells that are noninvasive, but not in those that are invasive. We found that its overexpression in invasive human breast tumor cells limited their motility and invasiveness in vitro and blocked their ability to colonize lungs in vivo, defining a new function for DDB2 in malignant progression. DDB2 overexpression attenuated the activity of NF-κB and the expression of its target matrix metalloprotease 9 (MMP9). Mechanistic investigations indicated that DDB2 decreased NF-κB activity by upregulating expression of IκBα by binding the proximal promoter of this gene. This effect was causally linked to invasive capacity. Indeed, knockdown of DDB2-induced IκBα gene expression restored NF-κB activity and MMP9 expression, along with the invasive properties of breast tumor cells overexpressing DDB2. Taken together, our findings enlighten understanding of how breast cancer cells progress to an invasive phenotype and underscore potential clinical interest in DDB2 as a prognostic marker or therapeutic target in this setting.

CD8-alpha T-cell infiltration in human papillomavirus-related oropharyngeal carcinoma correlates with improved patient prognosis.

Patients with human papillomavirus (HPV)-related oropharyngeal tumors display improved prognosis. The biological basis of this tumor phenotype is poorly understood. We investigated whether increased lymphocyte infiltrate in HPV-positive oropharyngeal squamous cell carcinomas could account for better prognosis. We previously identified, in an Affymetrix GeneChip analysis of 83 HPV-unrelated and 11 HPV-related squamous cell carcinoma of the oropharynx, several candidate genes, including CD8α and CD3ζ. Their expression was validated in this study by qRT-PCR on an independent clinical series of 144 oropharyngeal tumors. Immunohistochemical staining of tumor specimens was performed to evaluate infiltration of tumor stroma by CD8+ and CD4+ lymphocytes. The prognostic value of CD8α and CD3ζ expression levels was measured by Kaplan-Meier and Cox regression model analyses. Immune response-related signaling pathways were found to be deregulated in HPV-positive oropharyngeal tumors. Expression of CD8α, CD3ζ, granzyme K, CD28 and integrin αL RNAs was upregulated in HPV-positive lesions when compared with HPV-unrelated tumors (p < 0.05). Stroma of HPV-positive tumors was frequently and strongly infiltrated by CD8α- and CD3ζ-positive T cells. CD8α RNA expression correlated with both improved global (Kaplan-Meier; p = 0.005; Cox regression: p = 0.003) and disease-free (Cox regression: p = 0.04) survival. CD3ζ RNA expression correlated with improved overall survival (Cox regression: p = 0.024). These results suggest that an increased cytotoxic T-cell-based antitumor immune response is involved in improved prognosis of patients with HPV-positive tumors.

The NEDD8 conjugation pathway regulates p53 transcriptional activity and head and neck cancer cell sensitivity to ionizing radiation.

Human papillomavirus (HPV)-related oropharyngeal cancer represents a distinct head and neck squamous cell carcinoma (HNSCC) subpopulation, with improved disease-free and overall survival. In general, HPV-positive HNSCCs express wild-type TP53, which could explain its increased radiosensitivity. However, the molecular mechanisms underlying this higher sensitivity remain elusive. We have previously shown that HPV-related oropharyngeal carcinomas express decreased levels of the NEDD8-activating enzyme 1/amyloid ß precursor protein-binding protein 1 (NAE1/APP-BP1) gene. NAE1/APP-BP1 function is required for the NEDDylation of target proteins, and has been shown to be a negative regulator of p53 transcriptional activity. In this study, we addressed the hypothesis that NAE1/APP-BP1 expression levels regulate p53 activity and cell survival upon ionizing irradiation. We used the radiosensitive and naturally HPV16-infected UPCI:SCC90 cell line and the radioresistant and HPV-negative SQ20B cell line as the control. NAE1/APP-BP1 expression levels were modulated with expression constructs and siRNAs. Radiosensitivity was evaluated with clonogenic survival assays. p53 transcriptional activity was measured with a luciferase assay. The overexpression of NAE1/APP-BP1 in UPCI:SCC90 cells resulted in the increased NEDDylation of p53, inhibition of p53 activity and increased cell resistance to ionizing radiation. Conversely, the inhibition of NAE1/APP-BP1 expression in SQ20B cells induced p53-dependent cell death after treatment with X-rays. Taken together, these results indicate that NAE1/APP-BP1 and NEDDylation are invovled in modulating p53 activity and regulating its role in the response of cells to ionizing radiation. Our findings bring new insights in the molecular mechanisms underlying the increased radiosensitivity of HPV-related oropharyngeal tumors. This is of importance, as no reliable and robust predictive biomarkers for tumor response to radiotherapy are currently available. These results also have potential clinical significance, as drugs targeting NAE1/APP-BP1 have recently emerged as a novel therapeutic modality in cancer treatment.

An entire exon 3 germ-line rearrangement in the BRCA2 gene: pathogenic relevance of exon 3 deletion in breast cancer predisposition.

BACKGROUND: Germ-line mutations in the BRCA1 and BRCA2 genes are major contributors to hereditary breast/ovarian cancer. Large rearrangements are less frequent in the BRCA2 gene than in BRCA1. We report, here, the first total deletion of exon 3 in the BRCA2 gene that was detected during screening of 2058 index cases from breast/ovarian cancer families for BRCA2 large rearrangements. Deletion of exon 3, which is in phase, does not alter the reading frame. Low levels of alternative transcripts lacking exon 3 (Δ3 delta3 transcript) have been reported in normal tissues, which raises the question whether deletion of exon 3 is pathogenic. METHODS: Large BRCA2 rearrangements were analysed by QMPSF (Quantitative Multiplex PCR of Short Fluorescent Fragments) or MLPA (Multiplex Ligation-Dependent Probe Amplification). The exon 3 deletion was characterized with a "zoom-in" dedicated CGH array to the BRCA2 gene and sequencing. To determine the effect of exon 3 deletion and assess its pathogenic effect, three methods of transcript quantification were used: fragment analysis of FAM-labelled PCR products, specific allelic expression using an intron 2 polymorphism and competitive quantitative RT-PCR. RESULTS: Large rearrangements of BRCA2 were detected in six index cases out of 2058 tested (3% of all deleterious BRCA2 mutations). This study reports the first large rearrangement of the BRCA2 gene that includes all of exon 3 and leads to an in frame deletion of exon 3 at the transcriptional level. Thirty five variants in exon 3 and junction regions of BRCA2 are also reported, that contribute to the interpretation of the pathogenicity of the deletion. The quantitative approaches showed that there are three classes of delta3 BRCA2 transcripts (low, moderate and exclusive). Exclusive expression of the delta3 transcript by the mutant allele and segregation data provide evidence for a causal effect of the exon 3 deletion. CONCLUSION: This paper highlights that large rearrangements and total deletion of exon 3 in the BRCA2 gene could contribute to hereditary breast and/or ovarian cancer. In addition, our findings suggest that, to interpret the pathogenic effect of any variants of exon 3, both accurate transcript quantification and co-segregation analysis are required.

Tubulin tyrosine ligase like 12 links to prostate cancer through tubulin posttranslational modification and chromosome ploidy.

Prostate cancer is a common cause of death, and an important goal is to establish the pathways and functions of causative genes. We isolated RNAs that are differentially expressed in macrodissected prostate cancer samples. This study focused on 1 identified gene, TTLL12, which was predicted to modify tubulins, an established target for tumor therapy. TTLL12 is the most poorly characterized member of a recently discovered 14-member family of proteins that catalyze posttranslational modification of tubulins. We show that human TTLL12 is expressed in the proliferating layer of benign prostate. Expression increases during cancer progression to metastasis. It is highly expressed in many metastatic prostate cancer cell lines. It partially colocalizes with vimentin intermediate filaments and cellular structures containing tubulin, including midbodies, centrosomes, intercellular bridges and the mitotic spindle. Downregulation of TTLL12 affects several posttranslational modifications of tubulin (detyrosination and subsequent deglutamylation and polyglutamylation). Overexpression alters chromosomal ploidy. These results raise the possibility that TTLL12 could contribute to tumorigenesis through effects on the cytoskeleton, tubulin modification and chromosome number stability. This study contributes a step toward developing more selective agents targeting microtubules, an already successful target for tumor therapy.

Biological and clinical relevance of transcriptionally active human papillomavirus (HPV) infection in oropharynx squamous cell carcinoma.

Human papillomaviruses (HPV) are associated with a subset of head and neck squamous cell carcinoma (HNSCC), particularly HPV16. This study analyzed the presence and genotype of high risk HPVs, viral DNA load and transcription of the E6/E7 mRNAs, in 231 consecutive HNSCC. Twelve out of 30 HPV16 DNA-positive tumors displayed high E6/E7 mRNAs levels and were localized in the oropharyngeal region. While HPV-free and non-transcriptionally active HPV-related patients showed similar 5-years survival rates, E6/E7 expression was associated with a better prognosis. This emphasizes the importance of considering the transcriptional status of HPV-positive tumors for patient stratification. A gene expression profiling analysis of these different types of tumors was carried out. The most significant differentially expressed gene was CDKN2A, a known biomarker for HPV-related cancer. Assessing both the expression level of the E6/E7 mRNAs and of CDKN2A in HNSCC is required to detect active HPV infection. Chromosomic alterations were investigated by Comparative Genomic Hybridation (CGH) analysis of tumors with transcriptionally active HPV and HPV-negative tumors. The loss of the chromosomal region 16q was found to be a major genetic event in HPV-positive lesions. A cluster of genes located in 16q21-24 displayed decreased expression levels, notably APP-BP1 that is involved in the modulation of the transcriptional activity of p53. In conclusion, this study highlights important criteria required to predict clinically active HPV infection, identifies new biological pathways implicated in HPV tumorigenesis and increases the understanding of HPV-HNSCC physiopathology that is required to develop new targets for therapy.

CTIP2 expression in human head and neck squamous cell carcinoma is linked to poorly differentiated tumor status.

BACKGROUND: We have demonstrated earlier that CTIP2 is highly expressed in mouse skin during embryogenesis and in adulthood. CTIP2 mutant mice die at birth with epidermal differentiation defects and a compromised epidermal permeability barrier suggesting its role in skin development and/or homeostasis. CTIP2 has also been suggested to function as tumor suppressor in cells, and several reports have described a link between chromosomal rearrangements of CTIP2 and human T cell acute lymphoblast leukemia (T-ALL). The aim of the present study was to look into the pattern of CTIP2 expression in Head and Neck Squamous Cell Carcinoma (HNSCC). METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we analyzed CTIP2 expression in human HNSCC cell lines by western blotting, in paraffin embedded archival specimens by immunohistochemistry (IHC), and in cDNA samples of human HNSCC by qRT-PCR. Elevated levels of CTIP2 protein was detected in several HNSCC cell lines. CTIP2 staining was mainly detected in the basal layer of the head and neck normal epithelium. CTIP2 expression was found to be significantly elevated in HNSCC (p<0.01), and increase in CTIP2 expression was associated with poorly differentiated tumor status. Nuclear co-localization of CTIP2 protein and cancer stem cell (CSC) marker BMI1 was observed in most, if not all of the cells expressing BMI1 in moderately and poorly differentiated tumors. CONCLUSIONS/SIGNIFICANCE: We report for the first time expression of transcriptional regulator CTIP2 in normal human head and neck epithelia. A statistically significant increase in the expression of CTIP2 was detected in the poorly differentiated samples of the human head and neck tumors. Actual CTIP2, rather than the long form of CTIP2 (CTIP2(L)) was found to be more relevant to the differentiation state of the tumors. Results demonstrated existence of distinct subsets of cancer cells, which express CTIP2 and underscores the use of CTIP2 and BMI1 co-labeling to distinguish tumor initiating cells or cancer stem cells (CSCs) from surrounding cancer cells.

Analysis of a novel human gene, LOC92912, over-expressed in hypopharyngeal tumours.

We have identified by differential display a number of novel genes that are expressed in hypopharyngeal head and neck squamous cell carcinoma. We report here the characterisation of one of these novel human genes, LOC92912, that encodes a protein of 375 amino acids. The protein contains a RWD domain, a coiled-coil, and an E2 ubiquitin conjugating enzyme domain. LOC92912 is upregulated in about 85% of tumour samples. It is expressed in tumour masses and in invasive epithelium, and is located in the cytoplasm of cells. To gain insights into its functions, we identified potential interacting partners by immunoaffinity purification of the flag tagged protein followed by MALDI peptide mass fingerprinting mass spectrometry. Actin and six actin-binding proteins were unambiguously identified as potential interacting partners, suggesting that LOC92912's functions may be linked with the cytoskeleton. This novel human gene may represent a new target for cancer therapeutics.

BRCA1 testing in breast and/or ovarian cancer families from northeastern France identifies two common mutations with a founder effect.

OBJECTIVE: The purpose of this study was to determine whether two mutations detected frequently in a population of breast and/or ovarian cancer families originating from the northeastern part of France could be due to a founder effect. METHODS: 83 index cases of families ascertained to have a familial breast and/or ovarian cancer history, were screened for mutations in all coding exons of the BRCA1 gene, using combined DGGE and direct sequencing. For haplotype analysis, six polymorphic markers were used for allelotyping of mutation carriers and non carriers from nine families with 3600del11 mutation and four families with G1710X mutation. RESULTS: Of 83 index cases, 27 (32%) had 14 different BRCA1 mutations, one of which (G1710X), had not been reported in other populations. Two mutations were particularly common: 3600del11 in exon 11 accounted for 37% and the nonsense mutation G1710X in exon 18 for 15% of all mutations. We identified a common haplotype for each mutation suggesting a common founder for each recurrent mutation. No specific phenotype could be assigned to any of the common mutations. CONCLUSIONS: These data demonstrate geographical clustering and suggest a founder effect for particular BRCA1 mutations, which identification will facilitate carrier detection in French families with breast cancer and breast and/or ovarian cancer.

Wild-type p53 gene transfer into mutated p53 HT29 cells improves sensitivity to photodynamic therapy via induction of apoptosis.

Photodynamic therapy (PDT) is an effective local cancer treatment that induces cytotoxicity through the intracellular generation of reactive oxygen species. It is generally thought that p53 regulates chemotherapy and radiation therapy responsiveness via apoptosis induction control. The current study investigated whether cellular sensitivity to PDT is increased when a wild-type (wt) p53 status is restored by gene transfer in the established HT9blk Ala273-mutant p53 human colon cancer cell line. The photosensitizer accumulation was similar in both cell lines, and survival measurements using MTT test and clonogenic assays demonstrated that wt p53 transfected cells (HT29A4) were significantly more sensitive to chlorin e6-mediated PDT. P53 protein expression and its functionality as a transcription factor demonstrated through the induction of mdm2 transactivation, were not found to be directly involved in this differential photosensitivity. However, induction of caspase 3 activation (2.6-fold), leading to significant apoptosis induction 24-h after PDT was observed in HT29A4 cells. These results suggest that the introduction of wt p53 in HT29A4 potentiates the cell sensitivity to PDT through the induction of apoptosis in relation to p53 mutational status, but independently of p53 expression level and transcriptional activity.

Identification of genes associated with tumorigenesis and metastatic potential of hypopharyngeal cancer by microarray analysis.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer among men in the developed world. There is a need, for both clinical and scientific reasons, to find markers to identify patients with aggressive disease as early as possible, and to understand the events leading to malignant transformation and susceptibility to metastasis. We report the first large-scale gene expression analysis of a unique HNSCC location, the hypopharynx. Four normal and 34 tumour samples were analysed with 12 600 gene microarrays. Clusters of differentially expressed genes were identified in the chromosomal regions 3q27.3, 17q21.2-q21.31, 7q11.22-q22.1 and 11q13.1-q13.3, which, interestingly, have already been identified by comparative genomic hybridization (CGH) as major regions of gene amplification. We showed that six overexpressed genes (EIF4G1, DVL3, EPHB4, MCM7, BRMS1 and SART1) located in these regions are indeed amplified. We report 119 genes that are highly differentially expressed between 'early' tumours and normal samples. Of these, we validated by quantitative PCR six novel poorly characterized genes. These genes are potential new markers of HNSCC. Comparing patients with relatively nonaggressive and aggressive tumours (without or with clinical evidence of metastasis 3 years after surgery), we identified 164 differentially expressed genes potentially involved in the acquisition of metastatic potential. This study contributes to the understanding of HNSCC, staging patients into prognostic groups and identifying high-risk patients who may benefit from more aggressive treatment.

The transcription factor Net regulates the angiogenic switch.

Angiogenesis is fundamental to physiological and pathological processes. Despite intensive efforts, little is known about the intracellular circuits that regulate angiogenesis. The transcription factor Net is activated by phosphorylation induced by Ras, an indirect regulator of angiogenesis. Net is expressed at sites of vasculogenesis and angiogenesis during early mouse development, suggesting that it could have a role in blood vessel formation. We show here that down-regulation of Net inhibits angiogenesis and vascular endothelial growth factor (VEGF) expression in vivo, ex vivo, and in vitro. Ras-activated phosphorylated Net (P-Net) stimulates the mouse VEGF promoter through the -80 to -53 region that principally binds Sp1. P-Net and VEGF are coexpressed in angiogenic processes in wild-type mouse tissues and in human tumors. We conclude that Net is a regulator of angiogenesis that can switch to an activator following induction by pro-angiogenic molecules.

Amplicon mapping and transcriptional analysis pinpoint cyclin L as a candidate oncogene in head and neck cancer.

DNA gains targeting the 3q chromosome are common in head and neck squamous cell carcinomas, as well as in lung, ovarian, and cervical cancer. Several candidate oncogenes located on 3q were proposed, i.e., PIK3CA, p63, and eIF-5A2. However, none of these genes was found included in a narrow high-level amplification. Recently, microarray-based comparative genomic hybridization (array CGH) was developed for high-resolution screening of deletions and amplifications in tumor genomes. In this study, by microarray-based comparative genomic hybridization, we found a narrow 3q25.3 high-level amplification in a head and neck cancer cell line. We precisely delimited the 3-Mb length-amplified segment by semiquantitative PCR and measured the transcriptional level of every gene (RefSeq full-length mRNA) located inside this segment by cDNA microarray and quantitative reverse transcription-PCR. Four genes were overexpressed in three head and neck cancer cell lines with increased DNA copy number, compared with a control tongue cell line. We extended the transcriptional analysis of these four genes to 20 head and neck squamous cell carcinomas. Only one gene, cyclin L (ania-6a), is commonly overexpressed in primary tumors compared with corresponding normal tissues. This cyclin was previously pinpointed as a candidate for a role in promoting cell cycle entry. Thus, we propose cyclin L as a candidate oncogene in head and neck cancer.