Dysregulated cyclin D1 expression early in head and neck tumorigenesis: in vivo evidence for an association with subsequent gene amplification

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.

Amplicon mapping and expression profiling identify the Fas-associated death domain gene as a new driver in the 11q13.3 amplicon in laryngeal/pharyngeal cancer

PURPOSE

Amplification of the 11q13 region is a frequent event in human cancer. The highest incidence (36%) is found in head and neck squamous cell carcinomas. Recently, we reported that the amplicon size in 30 laryngeal and pharyngeal carcinomas with 11q13 amplification is determined by unique genomic structures, resulting in the amplification of a set of genes rather than a single gene.

EXPERIMENTAL DESIGN

To investigate which gene(s) drive the 11q13 amplicon, we determined the smallest region of overlap with amplification and the expression levels of all genes within this amplicon.

RESULTS

Using array-based comparative genomic hybridization analysis, we detected a region of approximately 1.7 Mb containing 13 amplified genes in more than 25 of the 29 carcinomas. Quantitative reverse transcription-PCR revealed that overexpression of 8 potential driver genes including, cyclin D1, cortactin, and Fas-associated death domain (FADD), correlated significantly with DNA amplification. FADD protein levels correlated well with DNA amplification, implicating that FADD is also a candidate driver gene in the 11q13 amplicon. Analysis of 167 laryngeal carcinomas showed that increased expression of FADD (P = 0.007) and Ser(194) phosphorylated FADD (P = 0.011) were associated with a worse disease-specific survival. FADD was recently reported to be involved in cell cycle regulation, and cancer cells expressing high levels of the Ser(194) phosphorylated isoform of FADD proved to be more sensitive to Taxol-induced cell cycle arrest.

CONCLUSION

Because of the frequent amplification of the 11q13 region and concomitant overexpression of FADD in head and neck squamous cell carcinomas, we hypothesize that FADD is a marker to select patients that might benefit from Taxol-based chemoradiotherapy.

OPN/CD44v6 overexpression in laryngeal dysplasia and correlation with clinical outcome

Laryngeal dysplasia is a common clinical concern. Despite major advancements, a significant number of patients with this condition progress to invasive squamous cell carcinoma. Osteopontin (OPN) is a secreted glycoprotein, whose expression is markedly elevated in several types of cancers. We explored OPN as a candidate biomarker for laryngeal dysplasia. To this aim, we examined OPN expression in 82 cases of dysplasia and in hyperplastic and normal tissue samples. OPN expression was elevated in all severe dysplasia samples, but not hyperplastic samples, with respect to matched normal mucosa. OPN expression levels correlated positively with degree of dysplasia (P=0.0094) and negatively with disease-free survival (P<0.0001). OPN expression was paralleled by cell surface reactivity for CD44v6, an OPN functional receptor. CD44v6 expression correlated negatively with disease-free survival, as well (P=0.0007). Taken as a whole, our finding identify OPN and CD44v6 as predictive markers of recurrence or aggressiveness in laryngeal intraepithelial neoplasia, and overall, point out an important signalling complex in the evolution of laryngeal dysplasia.

Chromosomal imbalances in oral squamous cell carcinoma: examination of 31 cell lines and review of the literature

Classical and molecular cytogenetic analysis, including fluorescence in situ hybridization (FISH) and chromosomal comparative genomic hybridization (CGH), were used to examine genetic changes involved in the development and/or progression of oral squamous cell carcinoma (OSCC). Of 31 OSCC cell lines studied, more than one-third expressed clonal structural abnormalities involving chromosomes 3, 7, 8, 9, and 11. Eleven OSCC cell lines were evaluated using CGH to identify novel genome-wide gains, losses, or amplifications. By CGH, more than half of the cell lines showed loss of 3p, gain of 3q, 8q, and 20q. Further, molecular cytogenetic analyses by FISH of primary tumors showed that the karyotypes of cell lines derived from those tumors correlated with specific gains and losses in the tumors from which they were derived. The most frequent nonrandom aberration identified by both karyotype and CGH analyses was amplification of chromosomal band 11q13 in the form of a homogeneously staining region. Our data suggest that loss of 9p and 11q13 amplification may be of prognostic benefit in the management of OSCC, which is consistent with the literature. The results of this study validate the relationship between these OSCC cell lines and the tumors from which they were derived. The results also emphasize the usefulness of these cell lines as in vitro experimental models and provide important genetic information on these OSCC cell lines that were recently reported in this journal.

Management of oral epithelial dysplasia: a review

One of the goals of the fourth meeting of The World Workshop on Oral Medicine (WWOM IV) included a review of the pathophysiology and future directions for the clinical management of patients with oral epithelial dysplasia, excluding the lips and oropharynx. In the pathophysiology review of dysplasia since WWOM III (1998-2006), a wide range of molecular changes associated with progression of dysplasia to squamous cell carcinoma were found. These include loss of heterozygosity, dysregulation of apoptosis, aberrant DNA expression, and altered expression of numerous tissue markers. Based on the literature search, no single molecular pathway has been identified as the primary factor in progression of dysplasia to squamous cell carcinoma. A systematic review of medical (i.e., nonsurgical) management strategies for the treatment of dysplastic lesions has shown promising results in short-term resolution of dysplasia in the small number of studies that met eligibility criteria for review. However, because of the limited periods of follow-up reported in these studies, it remains unclear as whether resolution of dysplasia would actually be a long-term benefit of these interventions. This question is particularly germane when it is considered in the context of prevention of future development of squamous cell carcinoma. Because of the lack of randomized controlled trials that have shown effectiveness in the prevention of malignant transformation, no recommendations can be provided for specific surgical interventions of dysplastic oral lesions either.

High-resolution mapping identifies a commonly amplified 11q13.3 region containing multiple genes flanked by segmental duplications

DNA amplification of the 11q13 region is observed frequently in many carcinomas. Within the amplified region several candidate oncogenes have been mapped, including cyclin D1, TAOS1 and cortactin. Yet, it is unknown which gene(s) is/are responsible for the selective pressure enabling amplicon formation. This is probably due to the use of low-resolution detection methods. Furthermore, the size and structure of the amplified 11q13 region is complex and consists of multiple amplicon cores that differ between different tumor types. We set out to test whether the borders of the 11q13 amplicon are restricted to regions that enable DNA breakage and subsequent amplification. A high-resolution array of the 11q13 region was generated to study the structure of the 11q13 amplicon and analyzed 29 laryngeal and pharyngeal carcinomas and nine cell lines with 11q13 amplification. We found that boundaries of the commonly amplified region were restricted to four segments. Three boundaries coincided with a syntenic breakpoint. Such regions have been suggested to be putatively fragile. Sequence comparisons revealed that the amplicon was flanked by two large low copy repeats known as segmental duplications. These segmental duplications might be responsible for the typical structure and size of the 11q13 amplicon. We hypothesize that the selection for genes through amplification of the 11q13.3 region is determined by the ability to form DNA breaks within specific regions and, consequently, results in large amplicons containing multiple genes.

Growth inhibition and apoptosis by (-)-epicatechin gallate are mediated by cyclin D1 suppression in head and neck squamous carcinoma cells

In recent studies, green tea components have been shown to induce cell growth arrest and apoptosis in head and neck squamous cell carcinoma (HNSCC) cells. In this report, we have investigated the effects of epicatechin gallate (ECG), one of the catechins in green tea, on anti-cancer activity in vitro. We found that cyclin D1 was highly expressed in HNSCC cells, and ECG suppressed 90% of cyclin D1 expression in SCC7 cells. We have also evaluated the effect of ECG on cell growth and apoptosis, showing that ECG (50 microM) exhibited a significant inhibition (50%) on the growth of SCC7 cells via G1 cell cycle arrest. ECG suppressed cyclin D1 in SCC7 cells in a dose- and time-dependent manner, and the suppression of the beta-catenin pathway by ECG is one of the mechanism to facilitate ECG-induced cell growth arrest. These results suggest that ECG has a potential usage as a chemopreventive agent in HNSCC.

Cyclin D1 and p21 is elevated in the giant cells of giant cell tumors

Alterations of cell cycle regulatory proteins, especially those that regulate G1 to S transition, have been implicated in the pathogenesis of a wide variety of human tumors. In previous studies we showed that that there is overexpression of cyclin D1 protein predominately in the giant cell component of giant cell tumors of bone. The purpose of this study was to investigate the mechanisms that may be responsible for cyclin D1 accumulation in giant cell tumors. Giant cell tumors have high levels of cyclin D1 mRNA and the giant cell-enriched population of these tumors have significantly more mRNA and protein expression of cyclin D1 than the mononuclear cell population. The giant cells also expressed higher levels of p21 protein and more p21 bound to cyclin D1 than the mononuclear cells. It is possible that p21 may be contributing to the cyclin D1 accumulation that occurs in the giant cells and perhaps even giant cell formation in these tumors. Additional studies are required to confirm the role of p21 in the pathogenesis of these tumors.

Molecular predictors of clinical outcome in patients with head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) involves the upper aerodigestive tract and can destroy the structure and function of organs involved in voice, speech, taste, smell and hearing, as well as vital structures necessary for survival. HNSCC has long been a treatment challenge because of the high rate of recurrences and of advanced disease at the time of diagnosis. Molecular identification of tissue biomarkers in diagnostic biopsy specimens may not only identify patients at risk for developing HNSCC but may also select patients that may benefit from more aggressive treatment modalities. Several biomarkers studied to date such as the proteins p53, cyclin D1, p16, Cox-2 enzyme, epidermal growth factor and vascular endothelial growth factor receptors, matrix metalloproteinases and the Fhit marker for genomic instability could be manipulated for the therapeutic benefit of these patients. This review presents the most updated information on molecular biomarkers with the greatest prognostic potential in HNSCC and discusses some factors that contribute to the controversy concerning their prognostic importance.

[The relationship between human papillomavirus and cyclin D1 gene amplification in squamous cell carcinomas of the head and neck]

INTRODUCTION

infection by oncogenic subtypes of human papillomavirus (HPV) and cyclin D1 gene (CCND1) amplification are frequent events in head and neck squamous cell carcinomas. The objective of this paper is to establish the relationship between the presence of human papillomavirus (HPV) gene sequences and the development of CCND1 gene amplification in these tumours.

MATERIALS AND METHODS

59 squamous cell carcinomas of the head and neck were studied for HPV types 6b and 16 and CCND1 gene amplification by polymerase chain reaction.

RESULTS

HPV DNA was detected in 14 tumors (24%). Ten of them were positive for the HPV type 6b and 4 for the HPV type 16. CCND1 gene amplification was found in 15 cases (25%). Although we have found a higher frequency of CCND1 amplification in the HPV-positive cases (36%, versus 22% in the HPV-negative cases), these differences were not statistically significant (P= 0,32).

CONCLUSIONS

The presence of HPV gene sequences does not seem to be related to a significative higher incidence of CCND1 gene amplification in the squamous cell carcinomas of the head and neck.

Latent membrane protein 1 encoded by Epstein-Barr virus modulates directly and synchronously cyclin D1 and p16 by newly forming a c-Jun/Jun B heterodimer in nasopharyngeal carcinoma cell line

Recently we confirmed that latent membrane protein 1 (LMP1) encoded by Epstein-Barr virus (EBV) accelerates a newly forming active c-Jun/Jun B heterodimer, a transcription factor, but little is known about the target gene regulated by it. In this paper, results indicated that a c-Jun/Jun B heterodimer induced by LMP1 upregulated cyclin D1 promoters activity and expression, on the contrary, downregulated p16, and maladjustment of cyclin D1 and p16 expression accelerated progression of cell cycle. Firstly, we found a c-Jun/Jun B heterodimer regulated synchronously and directly cyclin D1 and p16 in the Tet-on-LMP1-HNE2 cell line, in which LMP1 expression is regulated by Tet-on system. This paper investigated in depth function of the newly forming active c-Jun/Jun B heterodimer, and built new connection between environmental pathogenic factor, signal transduction and cell cycle.

Alterations of Rb Pathway Components Are Frequent Events in Patients with Oral Epithelial Dysplasia and Predict Clinical Outcome in Patients with Squamous Cell Carcinoma

OBJECTIVE

This study was designed to test the hypothesis that alterations in expression of G1/S modulators cyclin D1, p16 and pRb occur in patients with oral epithelial dysplasia, considered to be at increased risk for malignant transformation. In addition, the analysis of expression of all three markers in the same set of oral cancer patients would provide a unique opportunity to determine whether these alterations have cooperative or synergistic effects on oral cancer development and prognosis.

PATIENTS AND METHODS

A prospective study was undertaken to carry out immunohistochemical analysis of cyclin D1, p16 and pRb proteins in serial paraffin-embedded tissue sections of 220 oral squamous cell carcinomas (OSCCs), 90 potentially malignant lesions (52 oral hyperplastic lesions, 38 dysplasias) and 81 matched histologically normal oral tissues and correlated them with clinicopathological parameters. Ninety-eight OSCC patients were followed up for a maximum period of 94 months with overall median survival of 21 months.

RESULTS

Seventy-five of 90 (83%) potentially malignant lesions and 198 of 220 (90%) OSCCs showed altered expression of at least one of the proteins in the pRb pathway, while 10 of 90 (11%) patients with potentially malignant lesions and 40 (18%) of 220 OSCC patients showed all three alterations. Loss of p16 was the earliest event in oral tumorigenesis. In a multivariate model, loss of pRb was associated with transition from hyperplasia to dysplasia (OR = 3.727, p = 0.005). The transition of potentially malignant lesions to malignant stage was associated with pRb-/cyclin D1+ phenotype (OR = 2.294, p = 0.001) and p53+ phenotype (OR = 2.230, p = 0.002). Loss of pRb and accumulation of p53 (pRb-/p53+) phenotype was associated with histologic progression of the tumors and acquisition of invasive potential. Multivariate analysis using Cox's proportional hazards model revealed that pRb-/p53+ phenotype was the most significant adverse prognosticator for disease-free survival (hazards ratio, (HR) = 2.642, p = 0.004).

CONCLUSIONS

Deregulation of the p16/pRb/cyclin D1 pathway is an early event in acquisition of dysplasia, but deregulation of both pRb and p53 pathways is associated with malignant transformation and adverse prognosis in oral tumorigenesis.

Molecular markers in laryngeal squamous cell carcinoma: towards an integrated clinicobiological approach

Of the most frequent malignancies in the United States, cancers of the larynx and of the uterine corpus are the only ones not to show an increase in 5-year survival rates over the last 30 years. The increasing use of chemo- and radiotherapy and conservative surgery to preserve organs and their functions has probably led to a better quality of life in patients with laryngeal cancer, but has definitely failed to improve survival, which remains the primary aim. In our opinion, to reduce laryngeal cancer-related mortality, a change in clinical approach is required. We have reviewed the literature on the potential role of molecular markers in the clinical management of laryngeal cancer. We believe that some of the most significant biological markers might be integrated with the evaluation of behavioural risk factors, clinical TNM staging and histopathological grading for a novel clinicomolecular approach to laryngeal cancer. We foresee the use of the most promising biological markers in the phases of prevention, diagnosis, prognostic assessment and drug design.

Nuclear factor-kappaB inhibitors as sensitizers to anticancer drugs

The cytotoxicity of chemotherapeutic agents is attributed to apoptosis. Acquired resistance to the effects of chemotherapy has emerged as a significant impediment to effective cancer therapy. One feature that cytotoxic treatments of cancer have in common is their activation of the transcription factor nuclear factor-kappaB (NF-kappaB), which regulates cell survival. NF-kappaB activation suppresses the apoptotic potential of chemotherapeutic agents and contributes to resistance. What evidence is there that inhibitors of NF-kappaB might promote apoptosis in cancer cells and can NF-kappaB inhibitors be used to overcome resistance to chemotherapeutic agents?

Cyclin D1 Is a Valuable Prognostic Marker in Oropharyngeal Squamous Cell Carcinoma

Background: The current tumor-node-metastasis system is inadequate to accurately classify patients in terms of prognosis. Thus, with the availability of recently developed molecular tools, considerable interest lies in discovering prognostic markers in order to guide treatment decisions. In this study, we sought to determine the prognostic significance of the cell cycle regulator cyclin D1 in oropharyngeal squamous cell carcinoma (OSCC).

Experimental Design: We studied the protein expression levels of cyclin D1 on a tissue microarray composed of 63 OSCCs with long-term follow-up data available. Protein expression was analyzed with an automated in situ quantitative (AQUA) method which allows preservation of tissue morphology while quantifying protein expression in paraffin-embedded tissue.

Results: The mean follow-up time was 35 months. High cyclin D1 nuclear expression was associated with increased 5-year local recurrence rate (48% versus 15%), inferior 5-year disease-free survival (16% versus 58%), and inferior 5-year overall survival (17% versus 53%). In multivariate Cox regression, high nuclear cyclin D1 expression was an independent predictor for local recurrence, disease-free survival, and overall survival at 5 years.

Conclusions: Our results indicate that quantitative assessment of nuclear cyclin D1 expression level by automated in situ quantitative analysis is a strong predictor for outcome in OSCC. Thus, cyclin D1 may be a potential target for molecular intervention in patients with oropharyngeal squamous cell cancer.

Loss of E-cadherin and p27 expression is associated with head and neck squamous tumorigenesis

BACKGROUND

In neoplastic head and neck lesions, it has been found that the loss or reduction in E-cadherin expression is a late event and is associated with invasion. Low p27 levels have been associated with a poor prognosis in many different tumors, including laryngeal carcinoma. The authors investigated p27 and E-cadherin protein expression in the early stages of head and neck tumorigenesis and evaluated their predictive roles individually and in association with carcinogenesis.

METHODS

Tissue biopsies from 46 patients who were participants in 3 chemoprevention trials were analyzed for E-cadherin expression, and 40 samples were analyzed for p27 expression using immunohistochemistry.

RESULTS

The data suggested that loss of both E-cadherin expression and p27 expression occurred early during the preneoplastic steps of head and neck carcinogenesis, and loss of p27 protein expression alone (P=0.02) and in combination with loss of E-cadherin expression (P=0.04) was a significant predictor of the risk for head and neck carcinoma.

CONCLUSIONS

The loss of p27 expression may be useful in the construction of a risk model for head and neck carcinogenesis and may represent a potential target for chemopreventive interventions. Longer follow-up of the high percentage of low-risk preneoplastic lesions in the current study and validation in a larger sample size may be required to establish the predictive role of these abnormalities.

Multistep laryngeal carcinogenesis helps our understanding of the field cancerisation phenomenon: a review

In this paper, we try to briefly review the most recent knowledge on head and neck cancer, and especially multistep laryngeal carcinogenesis, and to simply explain how this has modified our understanding of field cancerisation phenomenon. Experimental studies, made possible by the recent evolution of microdissection systems, have demonstrated that the "spatial progression"of the histopathological phenotype in the surroundings of malignant or premalignant head and neck lesions correlates with molecular progression. Such a "spatial progression" can be hypothesised to reflect temporal progression. The field cancerisation process has been divided into three phases, each with its own histological and molecular characteristics. Each of these phases may have clinical implications: detection and monitoring of fields may help cancer prevention (molecular epidemiology), early detection of recurrence (or, more exactly, of second field tumours (SFTs)) (molecular diagnostics) and prognostic prediction after treatment. This model appears plausible, especially in explaining the development of multiple primary tumours (MPTs) in adjacent head and neck mucosal regions, with peculiar clinical and prognostic implications: These tumours can be defined as multiple field tumours (SFTs). However, the model, in our opinion, does not convincingly explain the development of second primary tumours (SPTs) at more distant sites, such as the lung, colon and prostate.

Head and neck cancer: The pursuit of molecular diagnostic markers

From a histopathologic perspective, head and neck squamous cell carcinoma (HNSCC) is a relatively straightforward diagnosis. However, the clinically useful information presently provided by pathologists is embarrassingly limited. Similarly, our ability to accurately identify the earliest premalignant lesions as well as predict which premalignant lesions are likely to progress to HNSCC is limited. Over the last decade, an explosive growth of knowledge related to the molecular biology of this disease has occurred, which is now being used to address these issues. For example, we now appreciate that there are multiple etiologies and multiple molecular mechanisms responsible for the development of HNSCC. New techniques have improved our ability to identify molecularly premalignant, but histologically benign lesions. Similarly, recent studies have been able to predict which premalignant lesions are likely to progress to HNSCC. In addition to having utility in the realm of early diagnosis, molecular diagnostics may have a profound impact on how we diagnose and report HNSCC. While still in the developmental stage, molecular protocols are being used to evaluate surgical margins, determine the location of unknown primary tumors, identify histologically undetectable lymph node metastasis, and predict which tumors are more likely to respond to a particular postsurgical adjuvant therapy.

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.

The effect of cyclin D1 overexpression in human head and neck cancer cells

Overexpression of cyclin D1 in head and neck cancer has been suggested to be a poor prognostic factor. To understand the role of cyclin D1 expression in head and neck cancer, we overexpressed cyclin D1 in TU182 (a cell line derived from pharyngeal cancer) using a retroviral vector. Stable transfectants were isolated by neomycin (G418) selection. Compared to the parental and control-vector transfected cells, the cyclin D1 transfected cells revealed a decrease of the G1/G0 population and resulted in continuous proliferation under low serum conditions. Proliferation assays revealed an increase in resistance to cisplatin in cyclin D1 overexpressing cells. These observation suggest that deregulation of cyclin D1 may reduce growth factor requirements and contribute to the resistance to some chemotherapeutic agents among head and neck cancer patients.

Molecular markers in clinical radiation oncology

Radiation therapy plays a critical role in the management of a majority of patients diagnosed with cancer. Identification of factors that help predict which patients are at risk for relapse within the irradiated field remains an active area of investigation. Although conventional clinical and pathologic factors have been helpful in identifying risk and guiding clinical decision-making for both local and systemic management, there is clearly a need to identify additional prognostic markers, which can aid in refining our treatment strategies and improving outcomes. A substantial amount of research efforts have been devoted to identifying molecular markers for prognostic and therapeutic strategies. The recent emergence of a powerful armamentarium of molecular tools has resulted in rapid expansion of our fund of knowledge and understanding of the molecular biology underlying tumor behavior and response. While a majority of these efforts have been focused on risk factors for metastatic disease and survival, there is a rapidly growing body of literature focused on molecular factors associated with radiation resistance and locoregional failure. In this review, we summarize recent advances and the available literature evaluating molecular markers as they relate to radiation sensitivity of solid tumors. Literature regarding the potential application of expression of genes related to apoptosis, angiogenesis, cell cycle, DNA repair and growth factors will be reviewed. Some of the basic biology and laboratory evidence demonstrating how the marker relates to radiation response and available correlative clinical studies employing these markers as prognostic tools are presented. The majority of molecular markers that have potential clinical significance with respect to radiation sensitivity and local control will be highlighted.

Prognostic significance of cyclin D1 amplification and overexpression in oral squamous cell carcinomas

Amplification and overexpression of cyclin D1 (CCND1) have been reported as independent prognostic indicators of several tumors. To investigate the association between CCND1 amplification and overexpression in oral squamous cell carcinomas (OSCCs), and to determine which is more reliable as a prognostic indicator, fluorescence in situ hybridization (FISH) on fine-needle aspiration (FNA) biopsies and immunohistochemistry were performed on 41 primary OSCCs (26 males, 15 females; mean age; 58.4 years, range 21-89 years). Thirteen patients were stage I, 13 were stage II, nine were stage III, and six were stage IV. CCND1 amplification and overexpression was detected in 13 (31.7%) and 27 (65.9%) of 41 cases. CCND1 was overexpressed in all cases showing CCND1 amplification. On the other hand, CCND1 overexpression was also detected in 14 of 28 cases (50.0%) lacked such amplification. Statistical analysis showed that the correlation between CCND1 overexpression and decreased survival just failed to reach statistical significance, and CCND1 amplification and nodal status were independent prognostic indicators. In conclusion, it will be necessary to investigate the other pathways that regulate CCND1 expression besides CCND1 amplification. From the present study, CCND1 amplification is a more reliable prognostic indicator than CCND1 overexpression in OSCCs.

Oral cancer: reviewing the present understanding of its molecular mechanism and exploring the future directions for its effective management

The present review aims to analyze the information available regarding the molecular mechanisms of Oral Carcinogenesis and explore the future directions where the field of Cancer Biology is venturing. Oncologists have excellently followed the proverb "Necessity is the mother of Invention". The desire to be more precise and comprehensive in their studies has led to the invention of some of the most innovative techniques like laser capture microdissection, comparative genomic hybridization, microarrays, and protein chips etc. Various Biotech companies and Cancer Institutes are on a hunt for anti-cancer drugs and molecular markers for cancers. These revolutionary approaches and the new breed of Oncologists have made the field very exciting and have generated the hope that finally the war against cancer would be won. In the end it is urged that the lead taken in other cancers like colon, breast, leukemia will be emulated in oral cancer. This is expected to provide a molecular blueprint for HNSCC, thus helping to identify suitable markers for the early detection of pre-neoplastic lesions, as well as novel targets for its pharmacological intervention.

Cyclin D1 genotype, response to biochemoprevention, and progression rate to upper aerodigestive tract cancer

BACKGROUND

Altered cyclin D1 expression in advanced preinvasive lesions of the upper aerodigestive tract (UADT) is associated with an increased risk of developing cancer and histologic progression during and after combination biochemopreventive therapy (13-cis-retinoic acid, alpha-interferon, and alpha-tocopherol). Both alleles of the adenine (A)/guanine (G) cyclin D1 polymorphism located at nucleotide 870 encode two alternatively spliced transcripts, but the A allele preferentially encodes a protein with an extended half-life. We investigated whether the cyclin D1 genotype at nucleotide 870 was associated with baseline levels of cyclin D1 protein, post-treatment modulation of cyclin D1 protein levels, histologic response to treatment, and the outcome for subjects with preinvasive UADT lesions after biochemopreventive therapy.

METHODS

UADT tissue biopsy samples were obtained before and 6 and 12 months after biochemopreventive treatment from 31 individuals with advanced preinvasive UADT lesions. Tissues were examined for cyclin D1 genotype (by DNA single-strand conformation polymorphism analysis), for cyclin D1 protein expression (by immunohistochemistry), and for cyclin D1 gene copy number (by fluorescence in situ hybridization). Associations of cyclin D1 genotype with histologic response to therapy and time to progression to a higher degree of dysplasia or invasive cancer were investigated. All statistical tests were two-sided.

RESULTS

The A allele was associated with increased baseline cyclin D1 expression in the parabasal epithelial layer (16 of 18 AA/AG subjects versus four of nine GG subjects; P =.02), decreased histologic response to biochemopreventive treatment (six of 21 AA/AG subjects versus four of 10 GG subjects; P =.70), decreased favorable modulation of cyclin D1 expression by the treatment (seven of 18 AA/AG subjects versus eight of nine GG subjects; P =.02), and shorter progression-free survival (P =.05).

CONCLUSIONS

The cyclin D1 A allele was associated with a diminished modulation of normal physiologic and treatment-induced decreased expression of cyclin D1, a decreased likelihood of response to biochemopreventive intervention, and an increased rate of progression to cancer development, findings that require validation in a larger cohort.

Potential marker of oral squamous cell carcinoma aggressiveness detected by fluorescence in situ hybridization in fine-needle aspiration biopsies

BACKGROUND

Amplification of chromosome 11q13 is a frequent event in carcinogenesis of the head and neck squamous cell carcinomas including oral carcinoma.

METHODS

Fluorescence in situ hybridization (FISH), using a BAC clone specific for the cyclin D1 gene (CCND1), was performed on specimens obtained by fine-needle aspiration biopsy (FNAB) from 50 patients with primary oral squamous cell carcinomas (OSCCs.).

RESULTS

The CCND1 numerical aberration was identified in 21 (42.0%) of 50 patients with primary OSCCs. The CCND1 amplification was determined in 16 (32.0%) of these patients. Immunohistochemical staining revealed that all 21 tumors showing the CCND1 numerical aberration overexpressed the CCND1 protein. The CCND1 numerical aberration was associated significantly with histopathologic grading (P = 0.032), the mode of invasion (P = 0.047), the presence of cancer cells at the resection margin (P = 0.033), pathologic lymph nodestatus (P = 0.045), disease recurrence (P = 0.004), and survival (P = 0.004). The disease-free and overall survival period of patients with the CCND1 numerical aberration was significantly shorter than that of patients without the CCND1 numerical aberration (P = 0.0016 and P = 0.0019, respectively). Moreover, a multivariate analysis showed that the CCND1 numerical aberration retained an independent prognostic value.

CONCLUSIONS

The CCND1 numerical aberration is useful both as a prognostic indicator that is independent of the TNM classification, and an indicator to assist in determination of the appropriate treatment for patients with OSCCs. Analysis of the CCND1 numerical aberration using FISH on FNABs may be a useful and practical method for predicting aggressive tumors, recurrence, and clinical outcome in patients with OSCCs.

Human papillomavirus infection and cyclin D1 gene amplification in laryngeal squamous cell carcinoma: biologic function and clinical significance

BACKGROUND

Human papillomavirus (HPV) infection is suspected to be a risk factor for head and neck, and in particular for laryngeal, carcinogenesis. Cyclin D1 gene (CCND1) overexpression and amplification have been shown to play a role as prognostic factors in many human cancers, among which are head and neck cancers.

METHODS

A literature review of the role in head and neck cancers of HPV infection and CCND1 overexpression and amplification was undertaken. We have evaluated the extent of the current knowledge in this field under the light of recent acquisitions, in particular, about a correlation between HPV infection, a suspected risk factor, and CCND1 amplification, a frequent mutation (about 20% of laryngeal cancers) and a prognostic factor in laryngeal SCC.

RESULTS AND DISCUSSION

The significant correlation between HPV infection and CCND1 amplification supports the hypothesis of the involvement of HPV infection in laryngeal carcinogenesis and suggests that HPV positive laryngeal cancers may constitute a different subset of tumors with a peculiar molecular pattern and thus with a different clinical behavior. HPV infection may be considered a synergistic risk factor with smoking and/or alcohol consumption to be investigated in heavy smokers and drinkers, thus contributing to the identification of patient at high-risk for the development of laryngeal cancer who should undergo strict follow-up and primary and secondary prevention.

Chemoprevention of head and neck cancer: an update

Squamous cell carcinoma of the head and neck is an important public health problem worldwide that is clearly associated with the widely accepted risk factors of tobacco smoking and alcohol use and is the end result of a multiyear, multipath disease process of progressive genetic and associated tissue damage. Chemoprevention, the use of drugs or other agents to inhibit, delay, or reverse this process, is recognized as a very promising and important area in head and neck cancer research. Chemoprevention research is based on the increasing body of knowledge of the biology underlying head and neck tumorigenesis and is expected to ultimately result in a decrease in the incidence of head and neck cancer.

Attenuation of transforming growth factor beta-induced growth inhibition in human hepatocellular carcinoma cell lines by cyclin D1 overexpression

Transforming growth factor-beta1 (TGF-beta1) causes growth inhibition in many cell types. Since its role in the outgrowth of human hepatocellular carcinoma (HCC) is not clearly understood, we investigated the growth inhibitory effects of TGF-beta1, the genetic and molecular integrity of TGF-beta receptors, and the expression levels of cell cycle regulating proteins in 11 human HCC cell lines. Of 11 cell lines, 3 (27%) showed growth inhibition to TGF-beta1, whereas the other 8 cell lines did not. We performed Southern and Northern analysis of TGF-beta type I and II receptors and examined poly-adenine track mutation of the TGF-beta type II receptor, but failed to find any genetic mutation. The transcriptional induction of plasminogen activator inhibitor-1 and p21(WAF1/CIP1) by TGF-beta were detected in all HCC cell lines, implying that the molecular integrity of the TGF-beta receptors might be intact. The amplification and overexpression of cyclin D1 gene was detected in 4 (50%) of 8 HCC cells that showed resistance to TGF-beta1. The suppression of cyclin D1 expression with antisense cyclin D1 facilitated the TGF-beta1-triggered growth inhibition in a TGF-beta1 resistant HCC cell line containing amplified cyclin D1 gene. In conclusion, the overexpression of cyclin D1 may be responsible for the attenuation of TGF-beta1 induced growth inhibition in some HCC cells.

Cyclin D1 amplification and p16(MTS1/CDK4I) deletion correlate with poor prognosis in head and neck tumors

OBJECTIVES/HYPOTHESIS

Cyclin D1, a cell cycle regulator localized to chromosome 11q13, is amplified in several human tumors including head and neck squamous cell carcinoma (HNSCC). Amplification and/or overexpression of cyclin D1 have been correlated to a poor prognosis. Deletion of the p16 gene, localized to 9p21, has also been observed in a significant proportion of HNSCC. The p16 gene regulates cyclin D1-CDK4 activity and prevents retinoblastoma tumor suppressor gene phosphorylation, thereby downregulating cellular proliferation. Detection of cyclin D1 amplification and p16 deletion using a simple and sensitive method will be valuable for the development of effective treatment modalities for head and neck cancer.

STUDY DESIGN

We have used fluorescence in situ hybridization (FISH) to study cyclin D1 amplification and p16 gene deletion in head and neck tumors. Both single- and dual-color FISH were performed.

METHODS

Paraffin-embedded tissues from 103 patients with HNSCC were analyzed using genomic DNA probes for cyclin D1 and p16. Dual-color FISH was performed with chromosome 11 or 9 centromeric probes as a control. Twenty-eight of these samples were analyzed for p16 expression by immunohistochemistry.

RESULTS

Cyclin D1 amplification was observed in 30% (31/103) of patients, and p16 deletion in 52% (54/103). Lack of p16 expression was observed in 64% (18/28) of patients. There was a good correlation between the deletion of p16 sequences and the loss of p16 expression (P = .008). Amplification of cyclin D1 had a statistically significant association with recurrence, distant metastasis, and survival at 36 months. There was a significant association between p16 deletion and the development of distant metastases. Cyclin D1 amplification and p16 deletion together correlated with recurrence, distant metastasis, and survival.

CONCLUSIONS

We demonstrate that FISH is a simple and sensitive method for detecting cyclin D1 amplification and p16 deletion in head and neck cancer. Our results suggest that these two genetic aberrations together portend a poorer outcome than either of the abnormalities alone in head and neck cancer.

Genetic instability in epithelial tissues at risk for cancer

Epithelial tumors develop through a multistep process driven by genomic instability frequently associated with etiologic agents such as prolonged tobacco smoke exposure or human papilloma virus (HPV) infection. The purpose of the studies reported here was to examine the nature of genomic instability in epithelial tissues at cancer risk in order to identify tissue genetic biomarkers that might be used to assess an individual's cancer risk and response to chemopreventive intervention. As part of several chemoprevention trials, biopsies were obtained from risk tissues (i.e., bronchial biopsies from chronic smokers, oral or laryngeal biopsies from individuals with premalignancy) and examined for chromosome instability using in situ hybridization. Nearly all biopsy specimens show evidence for chromosome instability throughout the exposed tissue. Increased chromosome instability was observed with histologic progression in the normal to tumor transition of head and neck squamous cell carcinomas. Chromosome instability was also seen in premalignant head and neck lesions, and high levels were associated with subsequent tumor development. In bronchial biopsies of current smokers, the level of ongoing chromosome instability correlated with smoking intensity (e.g., packs/day), whereas the chromosome index (average number of chromosome copies per cell) correlated with cumulative tobacco exposure (i.e., pack-years). Spatial chromosome analyses of the epithelium demonstrated multifocal clonal outgrowths. In former smokers, random chromosome instability was reduced; however, clonal populations appeared to persist for many years, perhaps accounting for continued lung cancer risk following smoking cessation.

Retinoid mechanisms and cyclins

Retinoids have been investigated for their effects in the prevention and treatment of cancer. Scores of synthetic and natural ligands suppress growth and normalize differentiation of cells in vitro and in vivo. The molecular mechanisms of these activities are being elucidated with the goal of improving the therapeutic index. Here we summarize recent advances in the understanding of retinoid signaling via nuclear receptors, corepressors, and coactivators and review the effects of retinoid treatment on cell-cycle control elements and cyclin proteins.

Telomerase activation cooperates with inactivation of p16 in early head and neck tumorigenesis

Alteration of the p16/pRb pathway may cooperate with telomerase activation during cellular immortalization and tumour progression. We studied p16 expression status by immunohistochemistry and telomerase activity using the TRAP assay in 21 premalignant lesions of the head and neck epithelium as well as 27 squamous-cell carcinomas. We also examined expression of other components of the pathway (cyclin D1 and pRb) as well as presence of human papillomavirus genomes which can target these molecules. 4 of 9 mild dysplastic lesions (44%), 8 of 12 moderate/severe dysplastic lesions (67%), and 25 of 27 squamous-cell carcinomas (92%) demonstrated high telomerase activity (P = 0.009). There was a parallel increase with severity of lesions for the trend in proportions of cases demonstrating p16 inactivation or cyclin D1 overexpression (P = 0.02 and P = 0.01, respectively). For Ki67, a marker of cell proliferation, this trend was not significant (P = 0.08). Human papillomavirus infection was only found in 4 cases among the 48 samples tested (8.3%). In conclusion, progression of disease is accompanied by a parallel and continuous increase in telomerase activity and alterations in cell cycle regulators (p16, cyclin D1), as proposed by in vitro models.

Potential molecular prognostic markers in head and neck squamous cell carcinomas

BACKGROUND

Current management strategies for squamous cell carcinoma of the head and neck (HNSCC) rely on an understanding of the natural history of the disease, along with the use of prognostic factors to guide selection of appropriate treatment. However, it is recognized that tumor heterogeneity limits the reliable use of currently available prognostic markers. With the evolving understanding of the genetic and molecular basis of human malignancies, there has been much interest in determining whether specific molecular changes in HNSCC might guide treatment decisions.

METHODS

A literature review of potential molecular markers relevant to HNSCC was undertaken and evaluated. It is evident that the published information is promising but, oftentimes, limited by a scarcity of large, uniformly staged and treated patients, from which the value of novel molecular markers can be assessed.

RESULTS

On the basis of the review of more than 100 articles, some of the emerging molecular markers that might provide independent prognostic information include epidermal growth factor receptor (EGFR), transforming growth factor-alpha (TGF-alpha), cyclin D1, and p53. This review will discuss the current status of these molecular factors and consequent implications for novel therapeutic approaches for patients with HNSCC.

CONCLUSION

With the evolving understanding that human malignancies have developed and progressed on the basis of accumulated molecular abnormalities, there is an existing body of work trying to determine whether such abnormalities can predict clinical behavior of HNSCC. Such studies have to be conducted rigorously to derive useful information. Nevertheless, the role of such molecular markers, and the possibility to exploit them for therapeutic gain, is already at the horizon.

Biomolecular markers as intermediate end points in chemoprevention trials of upper aerodigestive tract cancer

Head-and-neck squamous-cell cancer (HNSCC) is an important public-health problem, accounting for approximately 40,300 new cancer cases and 12,000 cancer deaths annually in the United States (Greenlee et al., [2000]). Patients with early-stage disease are often cured with surgery or radiotherapy but are at high risk for second primary tumor (SPT) development (Lippman and Hong, [1989]), and the majority of patients present with advanced disease, for which the outcomes have not markedly improved despite advances in combined-modality therapy (Vokes et al., [1993]). HNSCC arises from transformation of the genetic material of normal cells, followed by successive genetic alterations in a multistep fashion, leading to clonal evolution of progeny cells with a proliferative advantage (Vogelstein and Kinzler, [1993]), induced by tobacco carcinogens (Slaughter et al., [1953]). Chemoprevention aims at reversal of this process through re-regulation of growth and differentiation and possibly elimination of genetically and phenotypically aberrant clones. Chemoprevention studies in upper aerodigestive tract (UADT) cancers are based on these fundamental premises and the identification of molecular genetic and biologic cellular changes. These alterations represent biomarkers of the carcinogenesis process and ultimately, if validated, could serve as intermediate end points for these studies.

Carcinogenesis of head and neck cancer and the role of chemoprevention in its reversal

Head and neck cancer is an important public health problem worldwide, accounting for approximately 40,400 new cancer cases and 12,300 cancer deaths annually in the US. Although early-stage disease is often curable with surgery or radiotherapy, the majority of patients present with advanced disease in which despite advances in combined modality therapy the outcomes have not dramatically improved. Furthermore, patients cured of their initial early-stage head and neck squamous cell carcinoma are at high risk for development of second primary tumors, which pose the main threat to survival. An alternative approach in reducing the incidence and thus mortality associated with these cancers is chemoprevention, the use of agents to reverse, halt, or delay carcinogenesis. The carcinogenesis process in head and neck cancer results from a dysregulation of cellular proliferation, differentiation, and cell death resulting from field-wide exposure of the upper aerodigestive tract to tobacco smoking. Newly acquired knowledge in the field of tumor biology and of the genetic changes underlying carcinogenesis through the use of new molecular technology represents the basis on which chemoprevention efforts should be based.

Markers of proliferation in normal and leukoplakic oral epithelia

We have reviewed the recent literature on immunohistochemical markers of cell proliferation in normal oral epithelia and leukoplakias. Most findings, including our own, point to an increased proliferation in oral leukoplakias that correlates with the degree of dysplasia. Although the basal layer of normal oral epithelia showed a very low proliferative activity, oral leukoplakias, even those containing low-grade dysplasia, exhibited a very significant increase in proliferation. High-grade dysplasia could be clearly differentiated from both low-grade dysplasia and normal oral epithelia by the presence of proliferating cells in the superficial cell strata, i.e. above or superficial to the parabasal layer. These changes were detected with several markers including PCNA, Ki-67 (Mib-1), cyclin D1 and CENP-F as well as with procedures using pulse labeling with BrDU, IrDU and tritiated thymidine. Comparison of all methods showed more similarities than discrepancies. Nevertheless, because of its relative simplicity of use and universal acceptance in many other sites, Ki-67 (Mib-1) seems to be the most reliable immunohistochemical marker for future use in cancer prevention and therapeutic clinical trials.