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

Expressional variations of Kaiso: an association with pathological characteristics and field cancerization of OSCC

Background

A group of genetically altered cells that have not transformed into a clinical or histologically identifiable state of malignancy but contains a higher risk of transforming into one is known as the field of cancerization. Numerous molecules are being investigated for their significance in the development of this phenomenon. One such protein of this family is Kaiso also known as ZBTB33 (Zinc Finger and BTB Domain containing 33). This protein belongs to the POZ-ZF family of transcription factors and may have functional tasks similar to its other siblings such as the growth and development of vertebrates and the pathogenesis of neoplastic diseases. Nevertheless, its role in the pathogenesis, progression, epithelial mesenchyal transition and field cancerization in case of oral cancer still needs exploration. Hence, this study was designed to explore the expressional differences between the mucosa of controls and those diagnosed with oral squamous cell carcinoma (OSCC).

Methods

Soft tissue samples were obtained from the main tumor, tumor periphery and opposite buccal mucosa of 50 oral cancer patients, whereas normal mucosa was taken from 50 volunteers undergoing elective tooth removal. The acquired samples were subjected to Immunohistochemical exploration for expression of Kaiso and E-Cadherin. The expression was measured using Image-J IHC profiler and summed as Optical density. The Optical density values were then subjected to statistical analysis.

Results

Results revealed a significant differential expression of Kaiso between the mucosal tissues taken from oral cancer patients and controls (p-value: < 0.0001), showing almost 50% down-regulation of Kaiso in all three tissue samples taken from oral cancer patients as compared to normal mucosa.

Conclusion

Kaiso has a significant difference of expression in the mucosa of oral cancer patients as compared to the mucosa of normal patients, making it a probable contributor to disease pathogenesis and field cancerization.

Methyltransferases in the Pathogenesis of Keratinocyte Cancers

Recent evidence suggests that the disruption of gene expression by alterations in DNA, RNA, and histone methylation may be critical contributors to the pathogenesis of keratinocyte cancers (KCs), made up of basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), which collectively outnumber all other human cancers combined. While it is clear that methylation modifiers are frequently dysregulated in KCs, the underlying molecular and mechanistic changes are only beginning to be understood. Intriguingly, it has recently emerged that there is extensive cross-talk amongst these distinct methylation processes. Here, we summarize and synthesize the latest findings in this space and highlight how these discoveries may uncover novel therapeutic approaches for these ubiquitous cancers.

Small Molecules in the Treatment of Squamous Cell Carcinomas: Focus on Indirubins

Simple Summary

In this review, the genetic landscape of squamous cell carcinoma is related to the potential targets of indirubin-based small molecules in cancer therapy. Being a component of traditional Chinese medicine, indirubins are used to treat chronic or inflammatory diseases, and have received increasing attention in cancer treatment due to their proapoptotic and antiproliferative activity. Frequent genetic alterations of squamous cell carcinomas are summarized, and it is discussed how these may render tumors susceptible to indirubin-based small molecule inhibitors.

Abstract

Skin cancers are the most common malignancies in the world. Among the most frequent skin cancer entities, squamous cell carcinoma (SCC) ranks second (~20%) after basal cell carcinoma (~77%). In early stages, a complete surgical removal of the affected tissue is carried out as standard therapy. To treat advanced and metastatic cancers, targeted therapies with small molecule inhibitors are gaining increasing attention. Small molecules are a heterogeneous group of protein regulators, which are produced by chemical synthesis or fermentation. The majority of them belong to the group of receptor tyrosine kinase inhibitors (RTKIs), which specifically bind to certain RTKs and directly influence the respective signaling pathway. Knowledge of characteristic molecular alterations in certain cancer entities, such as SCC, can help identify tumor-specific substances for targeted therapies. Most frequently, altered genes in SCC include TP53, NOTCH, EGFR, and CCND1. For example, the gene CCND1, which codes for cyclin D1 protein, is upregulated in nearly half of SCC cases and promotes proliferation of affected cells. A treatment with the small molecule 5′-nitroindirubin-monoxime (INO) leads to inhibition of cyclin D1 and thus inhibition of proliferation. As a component of Danggui Longhui Wan, a traditional Chinese medicine, indirubins are used to treat chronic diseases and have been shown to inhibit inflammatory reactions. Indirubins are pharmacologically relevant small molecules with proapoptotic and antiproliferative activity. In this review, we discuss the current literature on indirubin-based small molecules in cancer treatment. A special focus is on the molecular biology of squamous cell carcinomas, their alterations, and how these are rendered susceptible to indirubin-based small molecule inhibitors. The potential molecular mechanisms of the efficacy of indirubins in killing SCC cells will be discussed as well.

DNA hypomethylation promotes invasion and metastasis of gastric cancer cells by regulating the binding of SP1 to the CDCA3 promoter

BACKGROUND

Cell division cycle associated protein-3 (CDCA3) has been reported frequently upregulated in various cancers. It has been progressively realized that changed DNA methylations occur in diverse carcinomas. However, the concrete involvement of CDCA3 and DNA methylation in gastric cancer (GC) still needs to be further elucidated.

METHODS

In this study, quantitative reverse-transcription polymerase chain reaction (PCR) was utilized to determine the relative expressions of CDCA3 in GC and normal tissue samples. The methylation condition of CDCA3 was determined by bisulfite-sequencing PCR (BSP) and methylation-specific PCR (MSP). A chromatin immunoprecipitation (ChIP) assay and luciferase activity assay was used for the interaction between transcription factors and promoters and binding site determination, respectively. The effects of knockdown or overexpression of specificity protein 1 (SP1) or CDCA3 on GC cells in vitro were further assessed via wound healing assay, colony formation assay, and matrigel invasion assay.

RESULTS

In comparison to paired normal tissues, CDCA3 expressions were significantly increased in the GC tissues. The CDCA3 expression was regulated by DNA methylation, with the CpG island hypomethylation responsible for CDCA3 upregulation of GC. ChIP assays verified that the activity of SP1 binding to the CDCA3 promoter was dramatically increased. When the CDCA3 expression was downregulated in MKN45 cells by knockdown SP1, the proliferation ability, healing ability, and invasive ability were significantly suppressed.

CONCLUSION

The process by which SP1 bound to the nearest promoter region was expedited in GC cells, by which DNA was hypomethylated and CDCA3 expression was promoted. The effect on cell proliferation and invasion by CDCA3 was under the regulation of SP1 and also affected by hypomethylation of DNA.

Oral epithelial dysplasia: Classifications and clinical relevance in risk assessment of oral potentially malignant disorders

After more than a decade, the World Health Organization (WHO) published the revised grading system for oral epithelial dysplasia in 2017. The revised classification has changes reflecting our evolution of understanding of the dysplastic process. Although the WHO 2017 three-tier grading system is the gold standard for histological diagnosis of oral potentially malignant disorders, it has certain limitations. Suggestions to overcome these limitations include the use of clinical determinants and molecular markers to supplement the grading system. It has also been suggested that a two-tier system may be more reproducible and clinically translatable for better management. These advances in the understanding of epithelial dysplasia are very important globally and for us in the Indian subcontinent, given the prevalence of habits (tobacco/areca nut) and burden of oral cancer in this part of the world. The following review traces the evolution of the grading system of dysplasia, its relevance and clinical utility.

CD38 affects the biological behavior and energy metabolism of nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC) is the most common malignant tumor type in Southern China and South-East Asia. Cluster of differentiation (CD)38 is highly expressed in the human immune system and participates in the activation of T, natural killer and plasma cells mediated by CD2 and CD3 through synergistic action. CD38 is a type II transmembrane glycoprotein, which was observed to mediate diverse activities, including signal transduction, cell adhesion and cyclic ADP-ribose synthesis. However, the significance of CD38 in NPC biological behavior and cellular energy metabolism has not been examined. In order to elucidate the effect of CD38 on the biological behavior of NPC cells, stable CD38-overexpressed NPC cell lines were established. It was demonstrated that CD38 promoted NPC cell proliferation with Cell Counting Kit-8 and colony formation assays. It was also indicated that CD38 inhibited cell senescence, and promoted cell metastasis. Furthermore, it was determined that CD38 promoted the conversion of cells to the S phase and decreased the content of reactive oxygen species and Ca²⁺. Additionally, cell metabolism assays demonstrated that CD38 increased the concentration of ATP, lactic acid, cyclic adenosine monophosphate and human ADP/acrp30 concentration in NPC cells. To investigate the possible mechanism, bioinformatics analysis and mass spectrometry technology was used to determine the most notably changing molecule and signaling pathways, and it was determined and verified that CD38 regulated the metabolic-associated signaling pathways associated with tumor protein 53, hypoxia inducible factor-1α and sirtuin 1. The present results indicated that CD38 may serve a carcinogenic role in NPC by regulating metabolic-associated signaling pathways.

CDCA3 mediates p21-dependent proliferation by regulating E2F1 expression in colorectal cancer

Dysregulated cell cycle progression serves a crucial role in tumor development. Cell division cycle-associated 3 (CDCA3) is considered a trigger of mitotic entry; it is an important part of the S phase kinase-associated protein 1/Cullin/F-box ubiquitin ligase complex and mediates the destruction of mitosis-inhibitory kinase wee1. However, little is known about the role of CDCA3 in cancer, particularly colorectal cancer (CRC). The present study aimed to explore the biological and clinical significance of CDCA3 in CRC growth and progression. CDCA3 expression was significantly associated with tumor progression and poor survival. Overexpression of CDCA3 increased proliferation in LoVo CRC cells, whereas CDCA3 knockdown in SW480 CRC cells led to decreased proliferation, in vitro and in vivo. Further mechanistic investigations demonstrated that reduced CDCA3 expression resulted in G1/S phase transition arrest, which was attributed to a significant accumulation of p21 in SW480 cells; conversely, increased CDCA3 expression promoted G1/S phase transition through decreased p21 accumulation in LoVo cells. It was also demonstrated that CDCA3 was able to regulate the expression of transcription factor E2F1, thereby repressing p21 expression. Taken together, these results suggested that overexpression of CDCA3 may serve a crucial role in tumor malignant potential and that CDCA3 may be used as a prognostic factor and a potential therapeutic target in CRC.

Combinational chromosomal aneuploidies and HPV status for prediction of head and neck squamous cell carcinoma prognosis in biopsies and cytological preparations

PURPOSE

Head and neck squamous cell carcinoma (HNSCC) is one of the most common human cancer types with a very poor prognosis despite improvements in therapeutic modalities. The major known risk factors are tobacco use and alcohol consumption or infection with high-risk human papilloma viruses (HPV), especially in oropharyngeal tumors. The current management based on the assessment of a variety of clinical and pathological parameters does not sufficiently predict outcome.

METHODS

Chromosomal alterations detected in HNSCCs were characterized by metaphase comparative genomic hybridization (CGH) and correlated with clinical parameters as well as survival time. Candidate regions were validated by quantitative polymerase chain reaction, fluorescence-in situ-hybridization (FISH) on dapped tumor tissue and liquid-based cytological smear preparations. In addition, HPV status was determined by polymerase chain reaction and simultaneous immunocytochemical p16^INK4a-Ki67 staining.

RESULTS

The most frequent DNA copy number gains were observed on chromosome arms 3q, 8q, 5p, 7q, 12p, and 12q. DNA copy number decreases occurred most frequently at 3p, 17p, 4q, and 5q. FISH analysis verified in part the observed alterations by CGH on dapped tissues and was especially able to detect the most frequent DNA copy changes in cytological specimens.

CONCLUSION

The combination of HPV status and prognostic copy number alteration detected by FISH in biopsies or cytological specimens may be an applicable protocol for screening head and neck cancer patients prior to therapy.

Serum and tissue markers in hepatocellular carcinoma and cholangiocarcinoma: clinical and prognostic implications

HCC represents the sixth most common cancer worldwide and the second leading cause of cancer-related death. Despite the high incidence, treatment options for advanced HCC remain limited and unsuccessful, resulting in a poor prognosis. Despite the major advances achieved in the diagnostic management of HCC, only one third of the newly diagnosed patients are presently eligible for curative treatments. Advances in technology and an increased understanding of HCC biology have led to the discovery of novel biomarkers. Improving our knowledge about serum and tissutal markers could ultimately lead to an early diagnosis and better and early treatment strategies for this deadly disease. Serum biomarkers are striking potential tools for surveillance and early diagnosis of HCC thanks to the non-invasive, objective, and reproducible assessments they potentially enable. To date, many biomarkers have been proposed in the diagnosis of HCC. Cholangiocarcinoma (CCA) is an aggressive malignancy, characterized by early lymph node involvement and distant metastasis, with 5-year survival rates of 5%-10%. The identification of new biomarkers with diagnostic, prognostic or predictive value is especially important as resection (by surgery or combined with a liver transplant) has shown promising results and novel therapies are emerging. However, the relatively low incidence of CCA, high frequency of co-existing cholestasis or cholangitis (primary sclerosing cholangitis –PSC- above all), and difficulties with obtaining adequate samples, despite advances in sampling techniques and in endoscopic visualization of the bile ducts, have complicated the search for accurate biomarkers. In this review, we attempt to analyze the existing literature on this argument.

Cyclin D1 overexpression correlates with poor tumor differentiation and prognosis in gastric cancer

Overexpression of cyclin D is associated with the molecular tumorigenesis of gastric cancer. The purpose of the present study was to investigate the expression of cyclin D in human gastric cancer and to determine the potential correlations between cyclin D expression and clinicopathological characteristics of specific histological types, as well as its prognostic significance. In the present study, the expression of the cyclin D1 (CCND1), cyclin D2 (CCND2) and cyclin D3 (CCND3) genes in gastric cancer patients was explored using the Oncomine database, and their correlation with overall survival (OS) and progression-free survival (PFS) was evaluated using Kaplan-Meier analysis. The prognostic significance of CCND1 protein expression was evaluated by western blot analysis of 32 matched specimens of gastric adenocarcinomas and normal tissues obtained from patients treated at the National Cheng Kung University Hospital (Tainan, Taiwan). Analysis of the Oncomine cancer microarray database revealed that CCND1 gene expression was significantly increased in gastric intestinal-type adenocarcinoma, while CCND2 was significantly increased in diffuse gastric adenocarcinoma, gastric intestinal-type adenocarcinoma and gastric mixed adenocarcinoma. Kaplan-Meier analysis indicated that overexpression of CCND1 was associated with reduced OS and PFS. In addition, overexpression of CCND1 and downregulation of CCND2 were significantly correlated with receptor tyrosine-protein kinase erb-2-negative tumors and poor differentiation. The ratio of relative CCND1 expression (expressed as the CCND1/β-actin ratio) in tumor tissues compared with that in normal tissues was correlated with poor differentiation (P=0.0018). In summary, CCND1 overexpression is associated with shorter survival in patients with gastric cancer and with poorly differentiated tumors.

Cyclin D1 as a therapeutic target of renal cell carcinoma- a combined transcriptomics, tissue microarray and molecular docking study from the Kingdom of Saudi Arabia

BACKGROUND

Renal cell carcinoma (RCC) is a seventh ranked malignancy with poor prognosis. RCC is lethal at metastatic stage as it does not respond to conventional systemic treatments, and there is an urgent need to find out promising novel biomarkers for effective treatment. The goal of this study was to evaluate the biomarkers that can be potential therapeutic target and predict effective inhibitors to treat the metastatic stage of RCC.

METHODS

We conducted transcriptomic profiling to identify differentially expressed genes associated with RCC. Molecular pathway analysis was done to identify the canonical pathways and their role in RCC. Tissue microarrays (TMA) based immunohistochemical stains were used to validate the protein expression of cyclinD1 (CCND1) and were scored semi-quantitatively from 0 to 3+ on the basis of absence or presence of staining intensity in the tumor cell. Statistical analysis determined the association of CCND1 expression with RCC. Molecular docking analyses were performed to check the potential of two natural inhibitors, rutin and curcumin to bind CCND1.

RESULTS

We detected 1490 significantly expressed genes (1034, upregulated and 456, downregulated) in RCC using cutoff fold change 2 and p value < 0.05. Hes-related family bHLH transcription factor with YRPW motif 1 (HEY1), neuropilin 2 (NRP2), lymphoid enhancer-binding factor 1 (LEF1), and histone cluster 1 H3h (HIST1H3H) were most upregulated while aldolase B, fructose-bisphosphate (ALDOB), solute carrier family 12 (SLC12A1), calbindin 1 (CALB1) were the most down regulated genes in our dataset. Functional analysis revealed Wnt/β-catenin signaling as the significantly activated canonical pathway (z score = 2.53) involving cyclin D1 (CCND1). CCND1 was overexpressed in transcriptomic studies (FC = 2.26, p value = 0.0047) and TMA results also showed the positive expression of CCND1 in 53 % (73/139) of RCC cases. The ligands - rutin and curcumin bounded with CCND1 with good affinity.

CONCLUSION

CCND1 was one of the important upregulated gene identified in microarray and validated by TMA. Docking study showed that CCND1 may act as a potential therapeutic target and its inhibition could focus on the migratory, invasive, and metastatic potential of RCC. Further in vivo and in vitro molecular studies are needed to investigate the therapeutic target potential of CCND1 for RCC treatment.

Expression of the extracellular sulfatase SULF2 is associated with squamous cell carcinoma of the head and neck

Sulfatase 2 (SULF2), an extracellular sulfatase that alters sulfation on heparan sulfate proteoglycans, is involved in the tumorigenesis and progression of several carcinomas. SULF2 expression has not been evaluated in squamous cell carcinoma of the head and neck (HNSCC). Here we report results of IHC of SULF2 expression in HNSCC tissue. SULF2 was detected in 57% of tumors (n = 40) with a significant increase in intensity and number of stained cells compared to adjacent cancer-free tissue (p-value < 0.01), increasing with cancer stage when comparing stages 1 and 2 to stages 3 and 4 (p-value 0.01). SULF2 was not detected in epithelial cells of cancer-free controls, and expression was independent of patient demographics, tumor location and etiological factors, smoking and HPV infection by p16 IHC analysis. Sandwich ELISA was performed on serum of HNSCC patients (n = 28) and controls (n = 35), and although SULF2 was detectable, no change was observed in HNSCC. Saliva, collected by mouthwash, from HNSCC patients (n = 8) and controls (n = 8) was also tested by ELISA in a preliminary investigation and an increase in SULF2 was observed in HNSCC (p-value 0.041). Overall, this study shows that SULF2 is increased in HNSCC independent of tissue location (oral cavity, oropharynx, larynx and hypopharynx), patient demographics and etiology. Although no change in SULF2 was detected in HNSCC serum, its detection in saliva makes it worthy of further investigation as a potential HNSCC biomarker.

Erlotinib and the Risk of Oral Cancer: The Erlotinib Prevention of Oral Cancer (EPOC) Randomized Clinical Trial

IMPORTANCE

Standard molecularly based strategies to predict and/or prevent oral cancer development in patients with oral premalignant lesions (OPLs) are lacking.

OBJECTIVE

To test if the epidermal growth factor receptor inhibitor erlotinib would reduce oral cancer development in patients with high-risk OPLs defined by specific loss of heterozygosity (LOH) profiles. Secondary objectives included prospective determination of LOH as a prognostic marker in OPLs.

DESIGN

The Erlotinib Prevention of Oral Cancer (EPOC) study was a randomized, placebo-controlled, double-bind trial. Accrual occurred from November 2006 through July 2012, with a median follow-up time of 35 months in an ambulatory care setting in 5 US academic referral institutions. Patients with OPLs were enrolled in the protocol, and each underwent LOH profiling (N = 379); they were classified as high-risk (LOH-positive) or low-risk (LOH-negative) patients based on their LOH profiles and oral cancer history. The randomized sample consisted of 150 LOH-positive patients.

INTERVENTIONS

Oral erlotinib treatment (150 mg/d) or placebo for 12 months.

MAIN OUTCOMES AND MEASURES

Oral cancer-free survival (CFS).

RESULTS

A total of 395 participants were classified with LOH profiles, and 254 were classified LOH positive. Of these, 150 (59%) were randomized, 75 each to the placebo and erlotinib groups. The 3-year CFS rates in placebo- and erlotinib-treated patients were 74% and 70%, respectively (hazard ratio [HR], 1.27; 95% CI, 0.68-2.38; P = .45). The 3-year CFS was significantly lower for LOH-positive compared with LOH-negative groups (74% vs 87%, HR, 2.19; 95% CI, 1.25-3.83; P = .01). Increased EGFR gene copy number correlated with LOH-positive status (P < .001) and lower CFS (P = .01). The EGFR gene copy number was not predictive of erlotinib efficacy. Erlotinib-induced skin rash was associated with improved CFS (P = .01).

CONCLUSIONS AND RELEVANCE

In this trial, LOH was validated as a marker of oral cancer risk and found to be associated with increased EGFR copy number (the target of the intervention). Erlotinib did not, however, improve CFS in high-risk patients with LOH-positive or high-EGFR-gene-copy-number OPLs. These results support incorporation of LOH testing as a prognostic tool in routine clinical practice but do not support erlotinib use in this setting.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00402779.

Chromosome instability predicts progression of premalignant lesions of the larynx

The histopathology of premalignant laryngeal lesions does not provide reliable information on the risk of malignant transformation, hence we examined new molecular markers which can easily be implemented in clinical practice. Dual-target fluorescence in situ hybridisation (FISH) for chromosome 1 and 7 centromeres was performed on tissue sections of laryngeal premalignancies in 69 patients. Chromosome instability was indicated by numerical imbalances and/or polysomy for chromosomes 1 and 7. Additionally, immunostainings for p53, Cyclin D1 and (p)FADD expression were evaluated. Malignant progression was recorded. Eighteen patients with carcinoma in situ (CIS) were treated after diagnosis and excluded from follow-up. Chromosome instability was strongly associated with a high risk of malignant transformation, especially in lower grade lesions (hyperplasia, mild and moderate dysplasia; odds ratio = 8.4, p = 0.004). Patients with lesions containing chromosome instability showed a significantly worse 5-year progression-free survival than those with premalignancies without chromosome instability (p = 0.002). Neither histopathology nor the protein markers predicted progression in univariate analysis, although histopathological diagnosis, p53 and FADD contributed positively to chromosome instability in multivariate analysis. Chromosome instability is associated with malignant progression of laryngeal premalignancies, especially in lower grade lesions. These results may contribute to better risk counselling, provided that they can be validated in a larger patient set.

Growth inhibition of head and neck squamous cell carcinoma cells by sgRNA targeting the cyclin D1 mRNA based on TRUE gene silencing

Head and neck squamous cell carcinoma (HNSCC) exhibits increased expression of cyclin D1 (CCND1). Previous studies have shown a correlation between poor prognosis of HNSCC and cyclin D1 overexpression. tRNase ZL-utilizing efficacious gene silencing (TRUE gene silencing) is one of the RNA-mediated gene expression control technologies that have therapeutic potential. This technology is based on a unique enzymatic property of mammalian tRNase ZL, which is that it can cleave any target RNA at any desired site by recognizing a pre-tRNA-like complex formed between the target RNA and an artificial small guide RNA (sgRNA). In this study, we designed several sgRNAs targeting human cyclin D1 mRNA to examine growth inhibition of HNSCC cells. Transfection of certain sgRNAs decreased levels of cyclin D1 mRNA and protein in HSC-2 and HSC-3 cells, and also inhibited their proliferation. The combination of these sgRNAs and cisplatin showed more than additive inhibition of cancer cell growth. These findings demonstrate that TRUE gene silencing of cyclin D1 leads to inhibition of the growth of HNSCC cells and suggest that these sgRNAs alone or combined with cisplatin may be a useful new therapy for HNSCCs.

Cytogenetic alterations and their molecular genetic correlates in head and neck squamous cell carcinoma: a next generation window to the biology of disease

Cytogenetic alterations underlie the development of head and neck squamous cell carcinoma (HNSCC), whether tobacco and alcohol use, betel nut chewing, snuff or human papillomavirus (HPV) causes the disease. Many of the molecular genetic aberrations in HNSCC result from these cytogenetic alterations. This review presents a brief introduction to the epidemiology of HNSCC, and discusses the role of HPV in the disease, cytogenetic alterations and their frequencies in HNSCC, their molecular genetic and The Cancer Genome Atlas (TCGA) correlates, prognostic implications, and possible therapeutic considerations. The most frequent cytogenetic alterations in HNSCC are gains of 5p14-15, 8q11-12, and 20q12-13, gains or amplifications of 3q26, 7p11, 8q24, and 11q13, and losses of 3p, 4q35, 5q12, 8p23, 9p21-24, 11q14-23, 13q12-14, 18q23, and 21q22. To understand their effects on tumor cell biology and response to therapy, the cytogenetic findings in HNSCC are increasingly being examined in the context of the biochemical pathways they disrupt. The goal is to minimize morbidity and mortality from HNSCC using cytogenetic abnormalities to identify valuable diagnostic biomarkers for HNSCC, prognostic biomarkers of tumor behavior, recurrence risk, and outcome, and predictive biomarkers of therapeutic response to identify the most efficacious treatment for each individual patient's tumor, all based on a detailed understanding of the next generation biology of HNSCC.

Oral field cancerization: an update on current concepts

There always exists a field with genetically altered cells with a high risk of developing premalignant and malignant lesions. It may often happen that an individual stem cell is genetically altered and can cause the formation of a clone or a patch which is likely to turn into a tumor. This explains the higher recurrence rates following tumor resections. It is essential to identify and to treat this field in order to have greater chances to prevent cancer and achieve a better outcome. This article reports concepts, theories and markers for the assessment of field cancerization.

An overview of the risk factors associated with multiple oral premalignant lesions with a case report of extensive field cancerization in a female patient

BACKGROUND

Field cancerization is a well-known and well-documented process of malignant transformation first coined by Slaughter et al. in 1953. Tobacco chewing was associated with the greatest increase in the risk of multiple oral premalignant lesions and may be the major source of field cancerization of the oral cavity in the Indian population. The field cancerization will probably help clinicians in complementing evaluation of pathologic biopsy specimens.

MATERIAL AND METHODS

We present a case report of field cancerization in a 63-year-old Indian female. She presented with an intra-oral generalized hyperkeratotic verruciform type white lesions involving right and left buccal mucosa, lower labial mucosa, upper and lower vestibule, dorsal, ventral and right lateral border of the tongue, hard and soft palate. Microscopic examination revealed features of verrucous carcinoma in one area, squamous cell carcinoma in another and carcinoma in situ in other areas. Based on the overall features in various areas of the oral cavity, the lesion was diagnosed as field cancerization.

CONCLUSION

Reviewing the literature revealed the presence of a field with genetically altered cells appear to be induced by tobacco (smoking/smokeless form). The large number of premalignant cells in the fields may increase cancer risk considerably. Thus screening and monitoring of the field may have serious implications for oral cancer prevention.

Chromosomal imbalances exclusively detected in invasive front area are associated with poor outcome in laryngeal carcinomas from different anatomical sites

Laryngeal squamous cell carcinoma (LSCC) is a malignant neoplasm exhibiting aggressive phenotype, high recurrence rate, and risk of developing second primary tumors. Current evidence suggests that cells in the invasive front of carcinomas have different molecular profiles compared to those in superficial areas. This study aimed to identify candidate genes in the invasive front and superficial cells from laryngeal carcinomas that would be useful as molecular markers. Invasive front and tumor surface cells of 32 LSCC were evaluated by high-resolution comparative genomic hybridization. Both CCND1 copy number gains and cyclin D1 protein expression were evaluated to confirm gains of 11q13.3. Losses of 3q26.2-q29 and 18q23 were confirmed by loss of heterozygosity analysis. The most frequent chromosomal alterations observed only in invasive front cells involved gains of 1p, 4q, and 9p and losses of 3p, 11p, 12p, 13q, 17q, 18p, 19q, 20q, 21q, and Xp. Gains of 11q13 were detected in both components from glottis and supraglottis but only in invasive front cells from transglottic tumors. Fluorescence in situ hybridization confirmed gains of CCND1/CPE11 in a subset of cases. In supraglottic tumors, cyclin D1 positivity was associated with distant metastasis (P = 0.0018) and with decreased disease-free survival (P = 0.042). Loss of heterozygosity at 3q26.2 and 18q23 were associated with lymph node involvement (P = 0.055) and worsened prognosis, respectively. In conclusion, this study revealed regions that could be targeted in the search for molecular markers in LSCC. Cyclin D1 may be useful as a prognostic marker in supraglottic tumors.

CDK4: A Key Player in the Cell Cycle, Development, and Cancer

The cell cycle is regulated in part by cyclins and their associated serine/threonine cyclin-dependent kinases, or CDKs. CDK4, in conjunction with the D-type cyclins, mediates progression through the G1 phase when the cell prepares to initiate DNA synthesis. Although CDK4-null mutant mice are viable and cell proliferation is not significantly affected in vitro due to compensatory roles played by other CDKs, this gene plays a key role in mammalian development and cancer. This review discusses the role that CDK4 plays in cell cycle control, normal development, and tumorigenesis as well as how small molecule inhibitors of CDK4 can be used to treat disease.

Overexpression of cell cycle regulator CDCA3 promotes oral cancer progression by enhancing cell proliferation with prevention of G1 phase arrest

Background

Cell division cycle associated 3 (CDCA3), part of the Skp1-cullin-F-box (SCF) ubiquitin ligase, refers to a trigger of mitotic entry and mediates destruction of the mitosis inhibitory kinase. Little is known about the relevance of CDCA3 to human malignancy including oral squamous cell carcinoma (OSCC). We aimed to characterize the expression state and function of CDCA3 in OSCC.

Methods

We evaluated CDCA3 mRNA and protein expression in both OSCC-derived cell lines and primary OSCCs and performed functional analyses of CDCA3 in OSCC-derived cells using the shRNA system.

Results

The CDCA3 expression at both the mRNA and protein levels was frequently up-regulated in all cell lines examined and primary tumors (mRNA, 51/69, 74 %; protein, 79/95, 83 %) compared to normal controls (p < 0.001). In contrast, no significant level of CDCA3 protein expression was seen in oral premalignant lesions (OPLs) (n = 20) compared with the expression in OSCCs. Among the clinical variables analyzed, the CDCA3 expression status was closely related to tumor size (p < 0.05). In addition, suppression of CDCA3 expression with shRNA significantly (p < 0.05) inhibited cellular proliferation compared with the control cells by arresting cell-cycle progression at the G1 phase. Further, there was up-regulation of the cyclin-dependent kinase inhibitors (p21^Cip1, p27^Kip1, p15^INK4B, and p16^INK4A) in the knockdown cells.

Conclusion

The current results showed that overexpression of CDCA3 occurs frequently during oral carcinogenesis and this overexpression might be associated closely with progression of OSCCs by preventing the arrest of cell-cycle progression at the G1 phase via decreased expression of the cyclin-dependent kinase inhibitors.

Peripheral T-cell Lymphoma with Cyclin D1 overexpression: a case report

Peripheral T-cell lymphomas not otherwise specified are generally considered aggressive non-Hodgkin lymphomas, because of poor natural outcome and response to therapy. They show a complex karyotype without any specific genetic hallmark. We report a case of peripheral T-cell lymphoma not otherwise specified with heterogeneous nuclear Cyclin D1 immunohistochemical overexpression, due to gene copy gain, a phenomenon similar to that observed in Mantle Cell Lymphoma characterized by t(11;14)(q13;q32). In this case report we underline the diagnostic pitfall rapresented by Cyclin D1 immunoistochemical overexpression in a T-cell lymphoma. Several pitfalls could lead to misinterpretation of diagnosis, therefore, we underlined the need to integrate the classical histology and immunohistochemistry with molecular tests as clonality or Fluorescence in situ hybridization.

Genome-wide screening for genetic alterations in esophageal cancer by aCGH identifies 11q13 amplification oncogenes associated with nodal metastasis

Background

Esophageal squamous cell carcinoma (ESCC) is highly prevalent in China and other Asian countries, as a major cause of cancer-related mortality. ESCC displays complex chromosomal abnormalities, including multiple structural and numerical aberrations. Chromosomal abnormalities, such as recurrent amplifications and homozygous deletions, directly contribute to tumorigenesis through altering the expression of key oncogenes and tumor suppressor genes.

Methodology/Principle Findings

To understand the role of genetic alterations in ESCC pathogenesis and identify critical amplification/deletion targets, we performed genome-wide 1-Mb array comparative genomic hybridization (aCGH) analysis for 10 commonly used ESCC cell lines. Recurrent chromosomal gains were frequently detected on 3q26-27, 5p15-14, 8p12, 8p22-24, 11q13, 13q21-31, 18p11 and 20q11-13, with frequent losses also found on 8p23-22, 11q22, 14q32 and 18q11-23. Gain of 11q13.3-13.4 was the most frequent alteration in ESCC. Within this region, CCND1 oncogene was identified with high level of amplification and overexpression in ESCC, while FGF19 and SHANK2 was also remarkably over-expressed. Moreover, a high concordance (91.5%) of gene amplification and protein overexpression of CCND1 was observed in primary ESCC tumors. CCND1 amplification/overexpression was also significantly correlated with the lymph node metastasis of ESCC.

Conclusion

These findings suggest that genomic gain of 11q13 is the major mechanism contributing to the amplification. Novel oncogenes identified within the 11q13 amplicon including FGF19 and SHANK2 may play important roles in ESCC tumorigenesis.

Malignant and nonmalignant gene signatures in squamous head and neck cancer

Genetic events specific to the pathogenesis of malignancy can offer clues to the tumorigenesis process. The objective of this study was to identify gene alterations that differentiate tumor and nontumor lesions in squamous head and neck cancer (HNSCC). DNA from 220 primary HNSCC with concurrently present tumor and nontumor lesions from the same patient was interrogated for genomic alterations of loss or gain of copy. Conditional logistic regression dealt with tumor and non-tumor records within a patient. Of 113 genes, 53 had univariate effects (P < 0.01), of which 16 genes remained in the multivariable model with P < 0.01. The model had a C-index (ROC) of 0.93. Loss of CDKN2B and gain of BCL6, FGF3, and PTP4A3 predicted tumor. Loss of BAK1 and CCND1 and gain of STCH predicted nontumor. This highly powered model assigned alterations in 16 genes specific for malignant versus nonmalignant lesions, supporting their contribution to the pathogenesis of HNSCC as well as their potential utility as relevant targets for further evaluation as markers of early detection and progression.

EZH2 promotes malignant phenotypes and is a predictor of oral cancer development in patients with oral leukoplakia

Oral leukoplakia (OL) is the most common premalignancy in the oral cavity. A small proportion of OLs progresses to oral squamous cell carcinoma (OSCC). To assess OSCC risk of OLs, we investigated the role of the transcriptional repressor enhancer of zeste homolog 2 (EZH2) in oral tumorigenesis and its clinical implication as an OSCC risk predictor. Immunohistochemistry was used to measure EZH2 expression in OLs from 76 patients, including 37 who later developed OSCC and 39 who did not. EZH2 expression was associated with clinicopathologic parameters and clinical outcomes. To determine the biological role of EZH2 in OL, EZH2 level was reduced using EZH2 siRNAs in Leuk-1 cells, its impact on cell cycle, anchorage-dependent/independent growth, and invasion was assessed. We observed strong EZH2 expression in 34 (45%), moderate expression in 26 (34%), and weak/no expression in 16 (21%) of the OLs. The higher EZH2 levels were strongly associated with dysplasia (P < 0.001) and OSCC development (P < 0.0001). Multivariate analysis indicated that EZH2 expression was the only independent factor for OSCC development (P < 0.0001). At 5 years after diagnosis, 80% of patients whose OLs expressed strong EZH2 developed OSCC whereas only 24% patients with moderate and none with weak/no EZH2 expression did so (P < 0.0001). In Leuk-1 cells, EZH2 downregulation resulted in G(1) arrest; decreased invasion capability, decreased anchorage-independent growth; downregulation of cyclin D1 and upregulation of p15(INK4B). Our data suggest that EZH2 plays an important role in OL malignant transformation and may be a biomarker in predicting OSCC development in patients with OLs.

CCND1 as a predictive biomarker of neoadjuvant chemotherapy in patients with locally advanced head and neck squamous cell carcinoma

Background

Cyclin D1 (CCND1) has been associated with chemotherapy resistance and poor prognosis. In this study, we tested the hypothesis that CCND1 expression determines response and clinical outcomes in locally advanced head and neck squamous cell carcinoma (HNSCC) patients treated with neoadjuvant chemotherapy followed by surgery and radiotherapy.

Methodology and Findings

224 patients with HNSCC were treated with either cisplatin-based chemotherapy followed by surgery and radiotherapy (neoadjuvant group, n = 100) or surgery and radiotherapy (non-neoadjuvant group, n = 124). CCND1 expression was assessed by immunohistochemistry. CCND1 levels were analyzed with chemotherapy response, disease-free survival (DFS) and overall survival (OS). There was no significant difference between the neoadjuvant group and non-neoadjuvant group in DFS and OS (p = 0.929 and p = 0.760) when patients treated with the indiscriminate administration of cisplatin-based chemotherapy. However, in the neoadjuvant group, patients whose tumors showed a low CCND1 expression more likely respond to chemotherapy (p<0.001) and had a significantly better OS and DFS than those whose tumors showed a high CCND1 expression (73% vs 8%, p<0.001; 63% vs 6%, p<0.001). Importantly, patients with a low CCND1 expression in neoadjuvant group received more survival benefits than those in non-neoadjuvant group (p = 0.016), however patients with a high CCND1 expression and treated with neoadjuvant chemotherapy had a significantly poor OS compared to those treated with surgery and radiotherapy (p = 0.032). A multivariate survival analysis also showed CCND1 expression was an independent predictive factor (p<0.001).

Conclusions

This study suggests that some but not all patients with HNSCC may benefit from neoadjuvant chemotherapy with cisplatin-based regimen and CCND1 expression may serve as a predictive biomarker in selecting patients undergo less than two cycles of neoadjuvant chemotherapy.

Review of MicroRNA Proposed Target Genes in Oral Cancer. Part II

Objectives

Cancer is the product of alterations in oncogenes, tumour suppressor genes and most recently microRNA genes not as a single event or single change but rather as a multistep process. The role of microRNA genes in carcinogenesis is recently explored and appears to be an early event in the pathogenesis of this as well as other disease processes and occurs via gene regulation by their own products, the microRNAs. The purpose of this article was to review the literature concerning MicroRNA proposed target genes in oral cancer.

Material and Methods

A review of the available literature from 2000 to 2011 regarding the potential roles assumed by microRNAs in oral cancer was undertaken using PubMed, Medline, Scholar Google and Scopus. Keywords for the search were: microRNA and oral cancer and target genes, microRNA deregulation and oral cancer, microRNA and carcinogenesis in the head and neck/oral cavity. English language full length articles were reviewed.

Results

Several microRNAs deregulated in oral cancer have been functionally validated and their exact target genes have been identified. Furthermore the carcinogenesis pathways impacted by these alterations has been proposed for some of these microRNAs.

Conclusions

The expanding knowledge of specific roles of certain microRNAs is further contributing to our understanding of the complexity of tumour progression and behaviour. Consideration of this information and incorporation into treatment modalities through targeted therapy could potentially enhance our abilities to improve outcome especially when other established therapies have failed.

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.

Cyclin D1 and cyclin D-dependent kinases enhance oral keratinocyte proliferation but do not block keratinocyte differentiation

Maintenance of oral epithelial homeostasis requires a fine balance between cell proliferation and differentiation. However, the molecular mechanisms that couple these processes, and its deregulation in tumorigenesis are not fully understood. Cyclin D1 and its kinase partners CDK4 and CDK6 play an important role in regulating the G1-S phase of the cell cycle. Deregulation of cyclin D1 is a frequent event in oral squamous cell carcinoma. Here, we examined whether overexpression of cyclin D1, CDK4 and CDK6 can deregulate the link between oral keratinocyte proliferation and differentiation. Our results show that cyclin D1 and its kinase partners CDK4 and CDK6 enhance keratinocyte proliferation, but are not sufficient to block calcium-induced keratinocyte differentiation and suggest that deregulation of these G1-regulatory kinases alone is insufficient to uncouple the link between proliferation and differentiation.

Serum markers of hepatocellular carcinoma

BACKGROUND

The hepatocellular carcinoma is one of the most common malignant tumors and carries a poor survival rate. The management of patients at risk for developing HCC remains intricate.

METHODS

A literature search identified potential markers for hepatocellular carcinoma. These markers were analysed and justification was provided for these factors' inclusion to (or exclusion from) the markers of hepatocellular carcinoma (HCC). A search of the literature was made using cancer literature and the PubMed database for the following keywords: "markers and HCC," "Lens culinaris agglutinin reactive AFP (AFP-L3) and HCC," "Des-γ-carboxy prothrombin (DCP) and HCC," "Glypican-3 and HCC," "Chromogranin A and HCC," "Transforming growth factor β1(TGF) and HCC," "α-l-fucosidase (AFU) and HCC," "Golgi protein-73 (GP73) and HCC," "Hepatocyte growth factor (HGF) and HCC," "Nervous growth factor (NGF) and HCC."

CONCLUSIONS

Despite the large number of studies devoted to the immunohistochemistry of HCC, at the present time, the absolute positive and negative markers for HCC are still lacking, and even those characterized by very high sensitivity and specificity do not have an universal diagnostic usefulness. Given the poor response to current therapies, a better understanding of the molecular pathways active in this disease could potentially provide new targets for therapy. However, AFP shows a low sensitivity, therefore other biomarkers have been developed to make an early diagnosis and improve patients' prognosis.

Ubiquitin-dependent proteolysis in G1/S phase control and its relationship with tumor susceptibility

Cell division depends upon the coordinated action of positive and negative regulatory factors that ensure high fidelity replication of the genome and its equivalent separation into daughter cells following cytokinesis. The role of positive factors such as the cyclin dependent kinases in promoting cell division is firmly established, as is the function of CDK inhibitors and phosphatases that antagonize CDKs. In addition to these, regulated protein destruction is now appreciated as essential for temporal regulation of cell cycle transitions. Protein degradation serves as an irreversible switch that ensures temporally regulated cell cycle transitions. Signal-dependent regulation of protein degradation is best understood with regard to the 26S proteasome. Proteins are directed to this machine subsequent to enzymatic transfer of a highly conserved small polypeptide, ubiquitin. The focus of this review is the regulatory molecules that direct the regulated attachment of ubiquitin, polyubiquitylation, to proteins destined for degradation as cells transition through the G1 phase into S-phase. During the past decade, it has become increasingly apparent that these molecules are critical mediators of normal cell proliferation and as such they are frequently deregulated in human cancers.

Molecular analysis of surgical margins in head and neck cancer: more than a marginal issue

The relatively modest survival of patients surgically treated for advanced HNSCC can partly be explained by the development of local relapse. It is important that surgeons are able to predict which patients are at high risk to develop local relapse, since clinical management can be tailored. Local relapse after resection of a primary HNSCC is easily explained, when tumour is detected in the surgical margins and thus residual tumour is likely to remain in the patient, but the pathobiology is more complex in cases where the margins are histologically tumour-free. Molecular studies indicate that there are two different mechanisms responsible in these cases. First, small clusters of residual tumour cells that are undetectable on routine histopathological examination (known as minimal residual cancer: MRC) proliferate and this forms the basis of recurring cancer. A second cause of relapse is a remaining field of preneoplastic cells that is struck by additional genetic hits leading to invasive cancer. It is likely that within this field, that can be over 7cm in diameter, the primary carcinoma has also emerged. Despite careful histopathological examination of the surgical margins of the primary carcinoma, it is at present not reliably possible to predict which patient will develop local relapse. Herein we focus on new developments regarding the analysis of margins, causes of local relapse, and how novel molecular techniques can be of help in a more accurate risk assessment. Critical analysis of the studies that have been published thus far shows that there is a list of promising markers, based on protein expression (immuno-histochemistry) and nucleic acid analysis. Further studies should be focused on validation and assessment of the clinical utility of these markers. Margin analysis should reveal whether one is dealing with residual cancer cells that might be treated by post-operative radiotherapy or with preneoplastic fields that remained behind. For this latter entity, there is no intervention available at present, except for a more intensive surveillance.

Phase II randomized, placebo-controlled trial of green tea extract in patients with high-risk oral premalignant lesions

Epidemiologic and preclinical data support the oral cancer prevention potential of green tea extract (GTE). We randomly assigned patients with high-risk oral premalignant lesions (OPL) to receive GTE at 500, 750, or 1,000 mg/m(2) or placebo thrice daily for 12 weeks, evaluating biomarkers in baseline and 12-week biopsies. The OPL clinical response rate was higher in all GTE arms (n = 28; 50%) versus placebo (n = 11; 18.2%; P = 0.09) but did not reach statistical significance. However, the two higher-dose GTE arms [58.8% (750 and 1,000 mg/m(2)), 36.4% (500 mg/m(2)), and 18.2% (placebo); P = 0.03] had higher responses, suggesting a dose-response effect. GTE treatment also improved histology (21.4% versus 9.1%; P = 0.65), although not statistically significant. GTE was well tolerated, although higher doses increased insomnia/nervousness but produced no grade 4 toxicity. Higher mean baseline stromal vascular endothelial growth factor (VEGF) correlated with a clinical (P = 0.04) but not histologic response. Baseline scores of other biomarkers (epithelial VEGF, p53, Ki-67, cyclin D1, and p16 promoter methylation) were not associated with a response or survival. Baseline p16 promoter methylation (n = 5) was associated with a shorter cancer-free survival. Stromal VEGF and cyclin D1 expression were downregulated in clinically responsive GTE patients and upregulated in nonresponsive patients at 12 weeks (versus at baseline). An extended (median, 27.5 months) follow-up showed a median time to oral cancer of 46.4 months. GTE may suppress OPLs, in part through reducing angiogenic stimulus (stromal VEGF). Higher doses of GTE may improve short-term (12-week) OPL outcome. The present results support longer-term clinical testing of GTE for oral cancer prevention.

Decreased expression of miR-125b and miR-100 in oral cancer cells contributes to malignancy

Altered microRNA (miRNA) expression profiles have been observed in numerous malignancies, including oral squamous cell carcinoma (OSCC). However, their role in disease is not entirely clear. Several genetic aberrations are characteristic of OSCC, with amplification of chromosomal band 11q13 and loss of distal 11q being among the most prevalent. It is not known if the expression levels of miRNAs in these regions are altered or whether they play a role in disease. We hypothesize that the expression of miRNAs mapping to 11q are altered in OSCC because of loss or amplification of chromosomal material, and that this contributes to the development and progression of OSCC. We found that miR-125b and miR-100 are down-regulated in OSCC tumor and cell lines, and that transfecting cells with exogenous miR-125b and miR-100 significantly reduced cell proliferation and modified the expression of target and nontarget genes, including some that are overexpressed in radioresistant OSCC cells. In conclusion, the down-regulation of miR-125b and miR-100 in OSCC appears to play an important role in the development and/or progression of disease and may contribute to the loss of sensitivity to ionizing radiation.

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.

Novel susceptibility loci for second primary tumors/recurrence in head and neck cancer patients: large-scale evaluation of genetic variants

This study was aimed to identify novel susceptibility variants for second primary tumor (SPT) or recurrence in curatively treated early-stage head and neck squamous cell carcinoma (HNSCC) patients. We constructed a custom chip containing a comprehensive panel of 9,645 chromosomal and mitochondrial single nucleotide polymorphisms (SNP) representing 998 cancer-related genes selected by a systematic prioritization schema. Using this chip, we genotyped 150 early-stage HNSCC patients with and 300 matched patients without SPT/recurrence from a prospectively conducted randomized trial and assessed the association of these SNPs with risk of SPT/recurrence. Individually, six chromosomal SNPs and seven mitochondrial SNPs were significantly associated with risk of SPT/recurrence after adjustment for multiple comparisons. A strong gene-dosage effect was observed when these SNPs were combined, as evidenced by a progressively increasing SPT/recurrence risk as the number of unfavorable genotypes increased (P for trend < 1.00 x 10(-20)). Several polygenic analyses suggest an important role of interconnected functional network and gene-gene interaction in modulating SPT/recurrence. Furthermore, incorporation of these genetic markers into a multivariate model improved significantly the discriminatory ability over the models containing only clinical and epidemiologic variables. This is the first large-scale systematic evaluation of germ-line genetic variants for their roles in HNSCC SPT/recurrence. The study identified several promising susceptibility loci and showed the cumulative effect of multiple risk loci in HNSCC SPT/recurrence. Furthermore, this study underscores the importance of incorporating germ-line genetic variation data with clinical and risk factor data in constructing prediction models for clinical outcomes.

Nuclear cyclin D1: an oncogenic driver in human cancer

Perturbations in the regulation of the core cell cycle machinery are frequently observed in human cancers. Cyclin D1 which functions as a mitogenic sensor and allosteric activator of CDK4/6, is one of the more frequently altered cell cycle regulators in cancers. Cyclin D1 is frequently overexpressed in cancers and its overexpression can be attributed to many factors including increased transcription, translation, and protein stability. Although cyclin D1 overexpression is clearly implicated in the affected cancers, overexpression of cyclin D1 is not sufficient to drive oncogenic transformation. Rather, emerging evidence suggests that nuclear retention of cyclin D1 resulting from altered nuclear trafficking and proteolysis is critical for the manifestation of its oncogenicity. This review provides a brief overview of current data documenting various mechanisms underlying aberrant cyclin D1 regulation in human cancers and their impact on neoplastic transformation.

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.

FOXM1 upregulation is an early event in human squamous cell carcinoma and it is enhanced by nicotine during malignant transformation

BACKGROUND

Cancer associated with smoking and drinking remains a serious health problem worldwide. The survival of patients is very poor due to the lack of effective early biomarkers. FOXM1 overexpression is linked to the majority of human cancers but its mechanism remains unclear in head and neck squamous cell carcinoma (HNSCC).

METHODOLOGY/PRINCIPAL FINDINGS

FOXM1 mRNA and protein expressions were investigated in four independent cohorts (total 75 patients) consisting of normal, premalignant and HNSCC tissues and cells using quantitative PCR (qPCR), expression microarray, immunohistochemistry and immunocytochemistry. Effect of putative oral carcinogens on FOXM1 transcriptional activity was dose-dependently assayed and confirmed using a FOXM1-specific luciferase reporter system, qPCR, immunoblotting and short-hairpin RNA interference. Genome-wide single nucleotide polymorphism (SNP) array was used to 'trace' the genomic instability signature pattern in 8 clonal lines of FOXM1-induced malignant human oral keratinocytes. Furthermore, acute FOXM1 upregulation in primary oral keratinocytes directly induced genomic instability. We have shown for the first time that overexpression of FOXM1 precedes HNSCC malignancy. Screening putative carcinogens in human oral keratinocytes surprisingly showed that nicotine, which is not perceived to be a human carcinogen, directly induced FOXM1 mRNA, protein stabilisation and transcriptional activity at concentrations relevant to tobacco chewers. Importantly, nicotine also augmented FOXM1-induced transformation of human oral keratinocytes. A centrosomal protein CEP55 and a DNA helicase/putative stem cell marker HELLS, both located within a consensus loci (10q23), were found to be novel targets of FOXM1 and their expression correlated tightly with HNSCC progression.

CONCLUSIONS/SIGNIFICANCE

This study cautions the potential co-carcinogenic effect of nicotine in tobacco replacement therapies. We hypothesise that aberrant upregulation of FOXM1 may be inducing genomic instability through a program of malignant transformation involving the activation of CEP55 and HELLS which may facilitate aberrant mitosis and epigenetic modifications. Our finding that FOXM1 is upregulated early during oral cancer progression renders FOXM1 an attractive diagnostic biomarker for early cancer detection and its candidate mechanistic targets, CEP55 and HELLS, as indicators of malignant conversion and progression.

Using Q-RT-PCR to measure cyclin D1, TS, TP, DPD, and Her-2/neu as predictors for response, survival, and recurrence in patients with esophageal squamous cell carcinoma following radiochemotherapy

PURPOSE

The purpose of this study was to evaluate the use of thymidilate synthetase (TS), thymidilate phosphorylase (TP), dihydropyrimidin dehydrogenase (DPD), Her-2/neu, and cyclin D1 as predictors of therapy response, survival, and recurrence in patients with esophageal squamous cell carcinoma (ESCC) following radiochemotherapy.

MATERIALS AND METHODS

Twenty-six patients with histologically proven intrathoracic, locally advanced ESCC (cT3, cN0/+, cM0) underwent preoperative, combined simultaneous radiochemotherapy followed by R0-transthoracic esophagectomy. Because R0 resection is the strongest known independent prognostic factor in this tumor entity, only R0-resected patients were included in this study. Pre-therapeutically taken, formalin-fixed, and paraffin-embedded tumor biopsies were used for laser-assisted microdissection of tumor cells and RNA extraction and subjected to real-time (TaqMan) quantitative reverse transcriptase-polymerase chain reaction (Q-RT-PCR).

RESULTS

No significant correlation between clinical or histopathological parameters and the relative gene expression of TS, TP, DPD, or Her-2/neu was observed. However, patients with relative cyclin D1 levels below the median gene expression did not reach median survival compared to the 19.9 months seen in patients with relative cyclin D1 gene expression above the median (P = 0.02). Patients with low cyclin D1 levels experienced significantly less frequent recurrence of the tumor (20% versus 63%; P = 0.006), and there was a significant difference in the recurrence-free interval (P = 0.003).

CONCLUSIONS

Despite the small number of investigated patients, our data seem to show that high levels of cyclin D1 measured by real-time Q-RT-PCR before neoadjuvant radiochemotherapy correlate significantly with patient survival, tumor recurrence, and recurrence-free-interval. Cyclin D1 might be useful in identifying patients at high risk of poor prognosis and suffering from recurrence after neoadjuvant radiochemotherapy treatment and R0 resection. Further investigations with a larger cohort are warranted.

Stromal control of oncogenic traits expressed in response to the overexpression of GLI2, a pleiotropic oncogene

Hedgehog signaling is often activated in tumors, yet it remains unclear how GLI2, a transcription factor activated by this pathway, acts as an oncogene. We show that GLI2 is a pleiotropic oncogene. Overexpression induces genomic instability and blocks differentiation, likely mediated in part by enhanced expression of the stem cell gene SOX2. GLI2 also induces TGFβ dependent transdifferentiation of foreskin and tongue, but not gingival fibroblasts into myofibroblasts, creating an environment permissive for invasion by keratinocytes, which are in various stages of differentiation having down regulated GLI2. Thus, up-regulated GLI2 expression is sufficient to induce a number of the acquired characteristics of tumor cells; however the stroma, in a tissue specific manner, determines whether certain GLI2 oncogenic traits are expressed.

Should there be more molecular staging of head and neck cancer to improve the choice of treatments and thereby improve survival?

PURPOSE OF REVIEW

Overall survival of head and neck squamous cell carcinoma patients on the whole has not dramatically improved in the last 30 years. One of the reasons is that tumour, node, metastasis classification is probably in some cases inadequate, since similar cases under a clinico-pathological point of view, may differ widely in prognosis. The most important reason for this is probably the extreme biological heterogeneity, which leads to a lack of consistency in treatment planning. The aim of the present review is to delineate the advances and the perspectives of clinical use of molecular characterization, which is an attempt to break through such molecular heterogeneity and to define, together with tumour, node, metastasis classification, homogeneous groups of patients for prognostic stratification and treatment selection.

RECENT FINDINGS

Among the markers evaluated in the last years, some have revealed particular promise. Epidermal growth factor receptor is probably the most reliable molecular marker at present, retaining its prognostic value independently from primary treatment. The p53 gene, the p53 protein being the main effector of DNA damage induced apoptosis, is probably the best predictor of radio/chemosensitivity.

SUMMARY

Even if clinical tumour, node, metastasis classification will probably retain its significance, it is now becoming possible, by molecular markers, to acquire biological information about host and tumour, to break through the above-cited molecular heterogeneity and eventually to optimize the choice of treatment.