Frequent amplification of 11q13 DNA markers is associated with lymph node involvement in human head and neck squamous cell carcinomas

Examination of a Low-density Lipoprotein Receptor Relative with 11 Ligand-binding Repeats (LR11) as a Biomarker in Esophageal Cancer

Objectives

Some previous studies reported that the levels of a low-density lipoprotein receptor relative with 11 ligand-binding repeats (LR11) was a prognostic marker in some malignant tumors; however, whether LR11 is related to survival in patients with esophageal cancer remains unclear.

Methods

In this study, we measured LR11 in the preoperative serum of 46 patients of esophageal cancer who undergoing surgery using a sandwich enzyme-linked immunosorbent assay (ELISA) method with anti-LR11 monoclonal antibodies. We investigated the correlation between the level of LR11 and survival of patients with esophageal cancer. Clinicopathological data were retrospectively retrieved from our institution's database.

Results

The patients were divided into two groups (low LR11 and high LR11) based on the level of LR11. There was no statistical difference in clinicopathological factors between these two groups. The low LR11 group had a significantly longer overall survival than the high LR11 group.

Conclusions

LR11 can be measured with a relatively simple ELISA and is potentially a new prognostic marker for esophageal cancer.

Decomposing the subclonal structure of tumors with two-way mixture models on copy number aberrations

Multistage tumorigenesis is a dynamic process characterized by the accumulation of mutations. Thus, a tumor mass is composed of genetically divergent cell subclones. With the advancement of next-generation sequencing (NGS), mathematical models have been recently developed to decompose tumor subclonal architecture from a collective genome sequencing data. Most of the methods focused on single-nucleotide variants (SNVs). However, somatic copy number aberrations (CNAs) also play critical roles in carcinogenesis. Therefore, further modeling subclonal CNAs composition would hold the promise to improve the analysis of tumor heterogeneity and cancer evolution. To address this issue, we developed a two-way mixture Poisson model, named CloneDeMix for the deconvolution of read-depth information. It can infer the subclonal copy number, mutational cellular prevalence (MCP), subclone composition, and the order in which mutations occurred in the evolutionary hierarchy. The performance of CloneDeMix was systematically assessed in simulations. As a result, the accuracy of CNA inference was nearly 93% and the MCP was also accurately restored. Furthermore, we also demonstrated its applicability using head and neck cancer samples from TCGA. Our results inform about the extent of subclonal CNA diversity, and a group of candidate genes that probably initiate lymph node metastasis during tumor evolution was also discovered. Most importantly, these driver genes are located at 11q13.3 which is highly susceptible to copy number change in head and neck cancer genomes. This study successfully estimates subclonal CNAs and exhibit the evolutionary relationships of mutation events. By doing so, we can track tumor heterogeneity and identify crucial mutations during evolution process. Hence, it facilitates not only understanding the cancer development but finding potential therapeutic targets. Briefly, this framework has implications for improved modeling of tumor evolution and the importance of inclusion of subclonal CNAs.

Clinical Implications of FADD Gene Amplification and Protein Overexpression in Taiwanese Oral Cavity Squamous Cell Carcinomas

Amplification of 11q13.3 is a frequent event in human cancers, including head and neck squamous cell carcinoma. This chromosome region contains several genes that are potentially cancer drivers, including FADD (Fas associated via death domain), an apoptotic effector that was previously identified as a novel oncogene in laryngeal/pharyngeal cancer. This study was designed to explore the role of FADD in oral squamous cell carcinomas (OSCCs) samples from Taiwanese patients, by assessing copy number variations (CNVs) and protein expression and the clinical implications of these factors in 339 male OSCCs. The intensity of FADD protein expression, as determined by immunohistochemistry, was strongly correlated with gene copy number amplification, as analyzed using a TaqMan CNV assay. Both FADD gene copy number amplification and high protein expression were significantly associated with lymph node metastasis (P < 0.001). Patients with both FADD copy number amplification and high protein expression had the shortest disease-free survival (DFS; P = 0.074 and P = 0.002) and overall survival (OS; P = 0.011 and P = 0.027). After adjusting for primary tumor status, tumor differentiation, lymph node metastasis and age at diagnosis, DFS was still significantly lower in patients with either copy number amplification or high protein expression (hazard ratio [H.R.] = 1.483; 95% confidence interval [C.I.], 1.044–2.106). In conclusion, our data reveal that FADD gene copy number and protein expression can be considered potential prognostic markers and are closely associated with lymph node metastasis in patients with OSCC in Taiwan.

Oral cancer overexpressed 1 (ORAOV1) regulates cell cycle and apoptosis in cervical cancer HeLa cells

BACKGROUND

Oral Cancer Overexpressed 1 (ORAOV1) is a candidate protooncogene locating on 11q13. Recent studies show that ORAOV1 acts as a primary driving force behind 11q13 gene amplification and plays a functional role in the tumorigenesis in a variety of human squamous cell carcinomas (SCCs). According to the results of molecular cytogenetic methods, 11q13 was characterized to be a high-level and recurrent amplification chromosomal site in cervical cancers. Up till now, the role of ORAOV1 in cervical cancer is unknown. The purpose of this study is to elucidate the function of ORAOV1 in cervical cancer cell growth by studying its roles in HeLa cells using small interfering RNA.

RESULTS

Functional analyses revealed that ORAOV1 was involved in the regulation of HeLa cell growth through its effect on cell cycle and apoptosis. Silence of ORAOV1 in HeLa cells downregulated the expression of Cyclin A, Cyclin B1 and Cdc2, and led to a distinct S cell cycle arrest. Moreover, knockdown of ORAOV1 expression activated both extrinsic and intrinsic apoptotic pathways and led to apoptosis in HeLa cells through its effect on the expression of several apoptosis related proteins such as P53, Bcl-2, Caspase-3, Caspase-8, Caspase-9 and cytochrome c. Interestingly, the expression of Cyclin D1, a pivotal gene for cervical cancer tumorigenesis, was also found to be reduced in ORAOV1 silenced HeLa cells.

CONCLUSION

Our findings indicate that ORAOV1 has an important role in regulating cell growth of cervical cancer HeLa cells through regulating the cell cycle and apoptosis. Thus, it may be a crucial protooncogene and a novel candidate therapeutic target for cervical cancer.

Overexpression of cortactin increases invasion potential in oral squamous cell carcinoma

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

An immunohistochemical study of cyclin D1 protein expression in laryngeal squamous cell carcinoma

CONCLUSION

Contrary to most reports, our study shows that the expression of cyclin D1 is not an independent prognostic factor in patients with laryngeal cancer (LC). No correlation between cyclin D1 expression and survival rates in LC was found in a multivariate analysis.

OBJECTIVES

The aim of this study was to determine the possible relevance of the expression of cyclin D1 protein in LC as prognostic criteria and to analyse correlation of the expression with clinicopathological features and survival rates.

MATERIALS AND METHODS

Immunohistochemistry staining was used to detect the expression of cyclin D1 in 130 samples of laryngeal cancer and in 22 specimens of laryngeal nodules.

RESULTS

Cyclin D1 expression was found in 52 (40%) LC samples and in 3 (13.6%) samples of laryngeal nodules. There was no significant correlation between cyclin D1 expression and clinicopathological features of LC. A multivariate analysis of survival confirmed that cyclin D1 expression was not an independent prognostic factor in LC.

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

BACKGROUND

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

METHODS

A literature search was performed.

RESULTS

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

CONCLUSIONS

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

Array-comparative genomic hybridization to detect genomewide changes in microdissected primary and metastatic oral squamous cell carcinomas

Oral squamous cell carcinoma (OSCC) is a common worldwide malignancy. However, it is unclear what, if any, genomic alterations occur as the disease progresses to invasive and metastatic OSCC. This study used genomewide array-CGH in microdissected specimens to map genetic alterations found in primary OSCC and neck lymph node metastases. We used array-based comparative genomic hybridization (array-CGH) to screen genomewide alterations in eight pairs of microdissected tissue samples from primary and metastatic OSCC. In addition, 25 primary and metastatic OSCC tissue pairs were examined with immunohistochemistry for protein expression of the most frequently altered genes. The highest frequencies of gains were detected in LMYC, REL, TERC, PIK3CA, MYB, MDR1, HRAS, GARP, CCND2, FES, HER2, SIS, and SRY. The highest frequencies of losses were detected in p44S10, TIF1, LPL, MTAP, BMI1, EGR2, and MAP2K5. Genomic alterations in TGFbeta2, cellular retinoid-binding protein 1 gene (CRBP1), PIK3CA, HTR1B, HRAS, ERBB3, and STK6 differed significantly between primary OSCC and their metastatic counterparts. Genomic alterations in PRKCZ, ABL1, and FGF4 were significantly different in patients who died compared with those who survived. Immunohistochemistry confirmed high PIK3CA immunoreactivity in primary and metastatic OSCC. Higher FGF4 immunoreactivity in primary OSCC is associated with a worse prognosis. Loss of CRBP1 immunoreactivity is evident in primary and metastatic OSCC. Our study suggests that precise genomic profiling can be useful in determining gene number changes in OSCC. As our understanding of these changes grow, this profiling may become a practical tool for clinical evaluation.

Numerical abnormalities of the Cyclin D1 gene locus on chromosome 11q13 in non-melanoma skin cancer

Deregulation of the cell-cycle G1-restriction point control via abnormalities of Rb-pathway components is a frequent event in the formation of cancer. The aim of this study was to evaluate numerical aberrations of the Cyclin D1 (CCND1, PRAD1, bcl-1) gene locus at chromosome 11q13 in basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) of the skin and to compare it with the Cyclin D1 protein expression. Fluorescence in situ hybridization with DNA-probes specific for the Cyclin D1 gene locus and the centromere of chromosome 11 as well as immunostaining for Cyclin D1 protein was applied on 5 microm serial paraffin sections. Six of the 30 (20%) SCCs showed additional Cyclin D1 gene copies and 2/30 (6.6%) cases had a loss of the Cyclin D1 gene locus in relation to the centromere 11 number. In contrast, only one of the 14 BCCs (7%) showed one additional Cyclin D1 gene copy in relation to the centromere 11 number. None of the BCCs demonstrated aneusomy for chromosome 11 in contrast to SCCs, where it was found in 21/30 (70%) cases. Twenty-six of the 30 (86.6%) cutaneous SCCs and 13/14 (93%) BCCs expressed Cyclin D1 protein. All SCCs and the BCC with additional Cyclin D1 gene copies showed positivity for Cyclin D1 protein. Both SCCs with less Cyclin D1 gene copies than centromere 11 signals showed a weak protein expression. Our findings suggest that numerical abnormalities of the Cyclin D1 gene locus could result in an altered gene-dose effect, possibly leading to an aberrant expression in affected tumor cells. This might result in deregulation of cell cycle control, eventually leading to uncontrolled cell cycle progression.

Molecular biology of transitional cell carcinoma

Transitional cell carcinoma (TCC) is the fifth most common solid malignancy in the USA. Radical cystectomy will cure a substantial fraction of patients with minimally invasive TCC, but approximately 50% of patients with muscle-invasive or extravesical disease treated by radical cystectomy alone die of metastatic TCC. Transitional cell carcinoma have a diverse collection of biologic and functional characteristics. This is reflected in a differing clinical course. The limited value of established prognosticators, make the analysis of new molecular parameters of interest in predicting the prognosis of bladder cancer patients; in particular, high-risk patient groups that are at risk of progression and recurrence. Over the past decade, there had been major progress in the elucidation of the molecular genetic changes leading to the development of TCC. This review will highlight these important advances and emphasize the ways in which molecular biology is likely to affect the development of future therapies.

Neck disease and distant metastases

While the implementation of multi-modality neoadjuvant therapy for the treatment of head and neck cancer has resulted in an improvement in local regional control, there has been a resultant increase in the reported incidence of distant metastasis. This shift in the pattern of patient treatment failure highlights the importance of identifying patients at high risk of developing metastasis, accurately detecting metastasis, and improving treatment strategies for advanced disease. Currently, metastatic lesions from head and neck primaries portend a poor prognosis; however, molecular biologic techniques offer a promising approach to the diagnosis and treatment of micrometastasis and distant metastatic lesions. The identification of tumor-specific gene mutations and the cell surface antigens may play a key role in the future management of head and neck cancer. The following review outlines just several of the current issues related to the contemporary diagnosis and management of metastatic lesions of the head and neck.

Prognostic significance of biomarkers in squamous cell carcinoma of the tongue: multivariate analysis

BACKGROUND AND OBJECTIVES

Expression of a panel of biomarkers, such as p53, Bcl-2, Cyclin D1, c-myc, p21ras, c-erb B2, cytokeratin-19 (CK-19), and factor VIII-related antigen (FVIII-RA), was studied together in anterior tongue tumors from the oral cavity and in posterior tongue tumors from the oropharynx of patients with early- and locally advanced-stage disease, to evaluate their prognostic value.

METHODS

The expression of the above-mentioned biomarkers was studied by immunohistochemical localization.

RESULTS

In this study, 18%, 26%, 62%, 75%, 73%, 50%, and 29% of the tumors exhibited p53, Bcl-2, Cyclin D1, c-myc, p21ras, c-erb B2, and CK-19 expression, respectively. Twenty percent of the tumors had a microvessel count of >0.0. The expression of these biomarkers was also correlated with clinicopathologic parameters. In early-stage patients with a tobacco habit, who showed borderline significance for relapse-free survival by Kaplan-Meier survival analysis, this turned out to be significant, with the general linear model univariate survival analysis. In the total group, disease stage emerged as the most significant prognostic factor, followed by c-myc, when Cox forward stepwise regression and general linear model multivariate survival analysis were performed. However, Cyclin D1, which was significant by Cox forward stepwise regression analysis, lost its significance by general linear model multivariate analysis. In patients with early-stage disease, MVC, which was a significant predictor of disease relapse by Cox forward stepwise regression analysis, lost its significance by general linear model analysis because of small number of patients. In patients with locally advanced tongue cancer, multivariate survival analysis of individual biomarkers by both Cox forward stepwise regression and general linear model analysis indicated c-myc expression to be strongly indicative of poor prognosis. However, multivariate analysis of individual markers along with a combination of markers showed that only by Cox forward stepwise regression analysis did the combined expression of markers c-myc, Cyclin D1, and p21ras emerge as a significant independent prognosticator.

CONCLUSIONS

Overall stage emerged as the most significant prognostic indicator of disease outcome. Tobacco habit also affected relapse-free survival in patients with early-stage disease. However, immunostaining of c-myc in the tumors of locally advanced-stage tongue cancer patients might be a potential adjunct to clinical stage in the pathologic evaluation of tongue specimens.

Loss of cyclin D1 and p16 expression correlates with local recurrence in nasopharyngeal carcinoma following radiotherapy

BACKGROUND

The cyclin D1/p16/Rb pathway plays a critical role in tumorigenesis and each component of this pathway may be affected in various malignancies. The purpose of this study was to investigate the expression and prognostic significance of these proteins in nasopharyngeal carcinoma (NPC).

PATIENTS AND METHODS

Sixty-five patients undergoing radiotherapy for NPC were analyzed. The expression of cyclin D1, p16 and pRb was evaluated with immunohistochemical analysis of archived pretreatment tumor materials and expression of these proteins was correlated with clinicopathological parameters.

RESULTS

Positive expression of cyclin D1 was observed in 43 of 65 NPCs (66%). p16 and pRb inactivation was identified in 42 of 65 (65%) and four of 65 (6%) tumors, respectively. All but seven tumors (58 of 65, 89%) contained at least one alternation in the cyclin D1/p16/Rb pathway. Loss of cyclin D1 as well as p16 was closely related to local recurrence after radiotherapy for NPC (P = 0.015 and 0.047). No association between pRb expression and clinicopathological outcome was apparent.

CONCLUSIONS

The study's results suggest that the cyclin D1/p16/Rb pathway plays an important role in NPC tumorigenesis. We also find that cyclin D1 and p16 protein levels in NPC may be of use clinically as a predictor of local tumor control.

Head and neck cancer: gene therapy approaches. Part II: genes delivered

In Part I, the review summarised the safety of adenoviral vectors and provided insight into approaches being undertaken to improve the specificity, durability and potency of adenoviral delivery vehicles. In Part II, brief discussions are held regarding results of preclinical and clinical trials with a variety of different genes, which have demonstrated antitumour activity in squamous cell carcinoma of the head and neck region (HNSCC). Studies have been performed with a variety of immune modulatory genes. Preliminary results demonstrate activity with several cytokine genes, tumour antigen genes and co-stimulatory molecule genes. Despite only preliminary results, thus far, a theoretical attractive feature for the use of gene therapy for the enhancement of immune modulation is that local injection of the gene product appears to be well tolerated. It is also successful in inducing systemic immune response, potentially providing effect to metastatic sites distal from the injected site. Animal studies have confirmed efficacy in the use of specific targeting of molecules regulating cancer growth (EGF receptor [EGFR], super oxide dismutase [SOD], cyclin D1, E1A and Bcl-2). These approaches are discussed. However, the most significant clinical advances for the use of gene therapy in advanced HNSCC involves two agents: Adp53 and ONYX-015. Preliminary Phase I and II results suggest evidence of efficacy and justify accrual Phase III trials, which are currently ongoing.

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.

Loss of MDM2 expression in human head and neck squamous cell carcinomas and clinical significance

The transforming potential of the MDM2 oncogene has been attributed to the overproduction of the protein. In order to investigate regulation of MDM2 expression in head and neck squamous cell carcinomas, we analysed MDM2 gene amplification, and mRNA and protein expression in tumour specimens from 62 patients, in cell lines, and in normal epithelium adjacent to tumours or obtained from healthy patients. Additionally, TP53-induced MDM2-P2 transcription was evaluated and compared with TP53 status. MDM2 gene amplification and mRNA over-expression is infrequent, 7 and 9%, respectively. The predominant transcript codes for full-length MDM2 protein (90kD) and the level of alternatively spliced forms is not significant. We show that only 47% of tumours exhibit MDM2 immunostaining in more than one third of the neoplastic cells, and thus more than half of the tumours display no or low levels of MDM2 protein. In contrast, MDM2 protein is always detectable in basal and parabasal cells of morphologically normal epithelium outside the invasively growing tumour, as well as in a normal uvula sample. Similarly, the total amount of MDM2 transcripts analysed by reverse transcriptase-polymerase chain reaction is reduced in tumour samples compared to normal tissues, essentially due to a decrease in P2 transcript levels. The relationship between mutated p53 status and low levels of MDM2 found in cell lines is also observed to a certain extent in primary tumour samples. Overall, there is a high frequency of TP53 mutation and under-expression of MDM2 in the head and neck tumours. Moreover, a significant association of decreased MDM2 expression is observed with advanced tumour stage and 3 years survival.

[CCND1 oncogene amplification and cellular DNA content in squamous cell carcinomas of the head and neck]

Cyclin D1 protein (encoded by the CCND1 gene) contributes to the progression of the cell cycle in the G1/S checkpoint. Cyclin D1 overexpression (for instance as a consequence of CCND1 amplification) might result in loss of control over genetic damage at this point and in an accumulation of chromosomal aberrations. In this work we analyze whether CCND1 amplification is associated with a higher incidence of alterations in cellular DNA content. 31 squamous cell carcinomas of the head and neck were studied. CCND1 amplification was determined by polymerase chain reaction. Cellular DNA content was determined by flow cytometry. CCND1 amplification was found in 6 (19%) cases. Thirteen (42%) cases were diploid and 18 (58%) were aneuploid. Two (33%) of the 6 cases with CCND1 amplification were aneuploid compared with 16 (64%) of the cases without CCND1 amplification (P = 0.36). We conclude that CCND1 amplification is not associated to a higher incidence of chromosomal aberrations in squamous cell carcinomas of the head and neck.

Expression of genetic markers in lymph node metastases compared with their primary tumours in head and neck cancer

Regional metastasis is an important factor in the prognosis and treatment of head and neck squamous cell carcinoma (HNSCC). The results of earlier studies suggested the possibility of predicting nodal metastasis in HNSCC using biological markers. To identify which factors may be relevant in the metastatic behaviour of these tumours, the expression of several markers involved in tumour progression was studied in both nodal metastases and their corresponding primary tumours. Expression of p53, Rb, cyclin D1, myc, bcl-2, EGFR, neu, E-cadherin, epithelial cell adhesion molecule (Ep-CAM), and nm23 was studied in 54 primary tumours and their corresponding metastases in patients with HNSCC. The expression of most genes involved in tumourigenesis (p53, Rb, cyclin D1, myc, bcl-2, EGFR, neu, and E-cadherin) was similar in primary tumours and metastases. The expression of nm23 and Ep-CAM was found to be more frequently lower than higher in metastases, compared with their primary tumours. Whereas most genetic alterations of primary tumours remain unchanged in metastases, expression of the cell adhesion molecule Ep-CAM and of nm23 is more frequently reduced than increased in metastases, compared with their primary tumours, suggesting relevance to the process of metastasis. This also implies differences in the regulation of markers involved in tumourigenesis and the process of metastasis.

Antisense cyclin D1 enhances sensitivity of head and neck cancer cells to cisplatin

OBJECTIVES

Cyclin D1 is a cell cycle regulatory factor that modulates a critical step in cell cycle control. Cyclin D1 is overexpressed in a significant proportion of head and neck cancers and correlates with a poor prognosis. Abrogation of cyclin D1 action through antisense cyclin D1 shows promise as an antitumor therapy, with an inhibitory effect in head and neck squamous cell carcinoma both in vitro and in vivo. The suppressive effect of antisense cyclin D1 in head and neck cancer xenografts in nude mice is incomplete, however, suggesting that combination with another antitumor agent is necessary for complete tumor eradication. Cisplatin is a widely used chemotherapeutic agent in head and neck cancer, and is particularly effective in combination with radiation therapy. In this study, we investigate whether antisense cyclin D1 enhances the sensitivity of head and neck cancer cells to cisplatin. Such an enhancement of sensitivity would suggest that combination therapy using antisense cyclin D1 and cisplatin would be an effective treatment modality for head and neck cancer.

STUDY DESIGN

Antisense cyclin D1 was transfected into the head and neck squamous cell carcinoma cell line CCL23 using a plasmid vector. Both the parental CCL23 cells and the antisense cyclin D1-transfected CCL23 cells (CCL23AS) were treated with cisplatin at increasing concentrations. The dosage of cisplatin ranged from 1 microg/mL to 10 microg/mL. Initial exposure to cisplatin was for 2 hours, with increasing exposure times in succeeding experiments. Cell viability assays were done following cisplatin exposure. Dose response curves for the two cell lines were plotted and compared. Western blot analyses were done on the cisplatin-treated cell lines to determine levels of cyclin D1 expression.

RESULTS

Increasing concentrations of cisplatin resulted in significantly higher rates of cell killing in the antisense cyclin D1-transfected cells than in the parental cells. The ID50 values for the parental CCL23 cells and the antisense cyclin D1-transfected CCL23 cells were 7 microg/mL and 3 microg/mL, respectively, indicating significant enhancement of sensitivity to cisplatin in the antisense cyclin D1-transfected cells. Western blot analyses demonstrated decreased expression of cyclin D1 in the CCL23AS cells with increasing doses of cisplatin, compared with the parental CCL23 cells.

CONCLUSIONS

Antisense cyclin D1-transfected CCL23 cells demonstrate an enhanced sensitivity to the effects of cisplatin compared with the parental cell line. Although the mechanism for this phenomenon is not completely understood, the data suggests the potential use of combination therapy using antisense cyclin D1 and cisplatin for head and neck cancers. While neither agent alone can completely eradicate head and neck cancers, the synergistic effect of the two may be an effective therapeutic protocol for refractory head and neck cancers. Future investigation into the combination of antisense cyclin D1 with cisplatin for treatment of head and neck cancer is needed.

Third place--Resident Research Competition, AAO-2000. Antisense cyclin D1 inhibits growth of head and neck cancer xenografts in nude mice

PROBLEM

Cyclin D1 is a regulatory factor essential in the progression of the cell cycle from G1 through S phase. Amplification and overexpression of cyclin D1 have been observed in many human cancers including head and neck squamous cell carcinoma (HNSCC). We have previously transfected a HNSCC control cell line (CCL23) with an antisense cyclin D1 plasmid and demonstrated inhibition of cell proliferation in vitro. In this study, we examine whether antisense cyclin D1 could inhibit tumor growth in vivo. Methods/measures: The CCL23 and its antisense cyclin D1 transfected clone (CCL23 AS) were injected into the flanks of nude mice. Tumor growth was monitored weekly. After 5 weeks, tumors were removed and studied for tumor size, cyclin D1 expression, cyclin D1-dependent kinase activity, and retinoblastoma (Rb) phosphorylation.

RESULTS

Compared with the control tumors, 11 of 19 antisense tumors were smaller, 7 tumors were of equal size, and 1 tumor was larger. Immunohistochemical analysis with an anti-cyclin D1 antibody demonstrated decreased cyclin D1 expression in CCL23 AS and the smaller antisense tumors. Cyclin D1-dependent kinase activity was reduced in CCL23 AS and the smaller antisense tumors, and this was accompanied by a relative decrease in phosphorylated Rb in these samples.

CONCLUSION

Antisense cyclin D1 inhibits growth of HNSCC tumors. Cyclin D1 expression, cyclin D1-dependent kinase activity, and Rb phosphorylation are decreased in these tumors.

CLINICAL SIGNIFICANCE

These findings lend support for the potential use of antisense cyclin D1 as gene therapy for HNSCC.

Apoptosis, proliferation and p53, cyclin D1, and retinoblastoma gene expression in relation to radiation response in transitional cell carcinoma of the bladder

PURPOSE

To determine whether the apoptotic index, the Ki67 index, and the expression of the p53, cyclin D1, and retinoblastoma genes correlate with local control, overall survival, and time to distant metastases in invasive bladder cancer treated with external beam radiation.

METHODS AND MATERIALS

Paraffin-embedded pretreatment biopsies from 83 patients with invasive transitional cell carcinoma of the bladder were scored morphologically for apoptosis and immunohistochemically for Ki67, p53, cyclin D1, and retinoblastoma gene expression. Survival analysis methods were used to assess overall survival, local control, and freedom from distant metastases. A multiple proportional hazard (PH) regression analysis was performed to study the prognostic value of the abovementioned biologic parameters (all divided into two categories, except Ki67) in addition to classical prognostic factors such as T stage, histologic grade, multifocality of the tumor, and completeness of transurethral resection. All patients were treated with external beam radiation as sole treatment. Median follow-up for the 19 patients still living was 7.5 years.

RESULTS

Apoptotic index varied from 0% to 3.4% with a mean of 0.8% and a median of 0.6%. Ki67 index varied from 0% to 60% with a mean of 14% and a median of 12%. P53 protein was detectable in 61% of the tumors. Overexpression of cyclin D1 was observed in 39% of the tumors and loss of retinoblastoma protein in 23% of the tumors. High Ki67 index was found to be significantly associated with p53 expression (p = 0.04) and cyclin D1 overexpression (p = 0.023). Cyclin D1 overexpression was found more often in Rb-positive tumors than in Rb-negative tumors (p = 0.006). Other associations between the markers are less clear. Biologic markers were not correlated with T stage or grade. In the PH analysis local control was found to be significantly better for tumors with wild-type p53 (p = 0.028). Also, tumors with an apoptotic index above the median value (0.6%) had a significantly better local control rate (p = 0.035). Ki67 index (p = 0.35), retinoblastoma gene expression (p = 0.30) and cyclin D1 overexpression (p = 0.61) were not found to have an additional predictive value regarding local tumor control. None of the tested biologic parameters were found to be associated with overall survival. Time to distant metastases was significantly shorter for tumors with high Ki67 index (p = 0.01) and tumors with an apoptotic index less than median (p = 0.009).

CONCLUSIONS

The results of our study provide evidence for a prognostic value of p53 expression and apoptotic index with respect to the radiation response in bladder cancer in addition to more conventional prognosticators. The value of these parameters as a predictive assay for radiation response warrants confirmation in larger and prospective studies.

[Molecular changes in epidermoid carcinoma of the oropharynx]

In most of the studies about molecular alterations in squamous cell carcinomas of the head and neck there is not distinction between the different subsites of this area. The objective of this study is to describe the molecular alterations in squamous cell carcinomas of the oropharynx. Twenty-nine oropharyngeal carcinomas, with a minimum follow-up of 36 months, were studied. The molecular alterations analyzed were: the amplification of 11q13 region (in the 29 cases), and the MYC and ERBB1 oncogenes (in 22 cases); the integration of Human Papillomavirus (HPV) types 6b and 16 (in 22 cases); the loss of heterozygosity (LOH) of p53 and N-acetyltransferase-2 (NAT2) gene (in 12 and 13 informative cases, respectively); and the cellular DNA content (in 13 cases). The most frequent alterations found were the LOH at p53 (67%), and NAT2 (54%) locus, followed by 11q13 amplification (49%). ERBB1 amplification was found in 14% of the cases, and MYC amplification only in one (5%). Integration of the HPV was found in 23% of the cases. Nine (69%) of the 13 analyzed cases were aneuploid. The only alteration with a prognostic significance was 11q13 amplification that showed a tendency to be associated with a higher frequency of nodal metastases and tumor recurrence.

A review of inherited cancer syndromes and their relevance to oral squamous cell carcinoma

This paper examines the genetic defects associated with inherited cancer syndromes and their relevance to oral cancer. Tumour suppressor genes are now thought of as either gatekeepers or caretakers according to whether they control cell growth directly by inhibiting cell proliferation and/or promoting cell death (gatekeepers) or whether they maintain the integrity of the genome by DNA repair mechanisms (caretakers). In disorders such as xeroderma pigmentosum, ataxia telangiectasia, Bloom syndrome and Fanconi's anaemia, where there are defective caretaker genes, there is an increased incidence of second primary malignancies, including oral cancer. By contrast, with the exception of Li Fraumeni syndrome, abnormalities of gatekeeper genes do not predispose to oral cancer. Not only do Li Fraumeni patients develop second primary malignancies, but defects of the p53 pathway (p53 mutation, MDM2 over-expression, CDKN2A deletion) appear to be a ubiquitous feature of sporadic oral cancer as it occurs in the West. The findings suggest that genetic instability is of fundamental importance in the pathogenesis of oral cancer.

Genetic aberrations in oral or head and neck squamous cell carcinoma 3: clinico-pathological applications

The molecular changes in malignant epithelium in the head and neck offer possibilities for the development of diagnostic, prognostic and other markers. This article reviews recent developments in this field.

DNA alterations in tumor scrapes vs. biopsies of squamous-cell carcinomas of the head and neck

Genetic abnormalities in SCCHNs are frequent and may be useful for screening, follow-up and prognosis. A biopsy or resection generally is utilized to identify these alterations but analysis of scraped or exfoliated tumor cells has been proposed as simpler and more versatile. It is unknown how well genetic abnormalities in scrapes reflect those in the tumor. Therefore, we compared DNA alterations in tumor scrapes obtained prior to treatment with alterations in microdissected tumor biopsies. Eight primary squamous-cell carcinomas of the head and neck (SCCHNs) were examined at 14 loci to determine loss of heterozygosity (LOH) at sites on 3p, 9p, 11p, 11q and 17p and amplification of cyclin D1 (CCND1). All biopsies contained DNA alterations, but only 3/8 scrapes contained unequivocal abnormalities; 4/8 contained subtle alterations that could not have been definitively identified without comparison to the paired biopsies. Overall, 22 alterations were detected in the biopsies: 8/22 were found unequivocally in the scrapes; 7/22 were identifiable in scrapes only after the biopsy alterations were defined and 7/22 were absent from scrapes. One LOH in scrape, but not biopsy, DNA was found. Discrepancies between scrapes and tumors tended to increase if multiple tumor samples were examined. We conclude that DNA alterations can be detected in scrapes of SCCHNs but may inaccurately reflect the tumor's complex genetic abnormalities. This may be due to contamination of scrapes with normal cells or to genetic heterogeneity within the tumor not represented in the scrape. Although examining scrapes of SCCHNs is an attractive technique, its clinical utility may have limitations.

Cyclin D1 overexpression is an indicator of poor prognosis in resectable non-small cell lung cancer

Cyclin D1 is one of the G1 cyclins that control cell cycle progression by allowing G1 to S transition. Overexpression of cyclin D1 has been postulated to play an important role in the development of human cancers. We have investigated the correlation between cyclin D1 overexpression and known clinicopathological factors and also its prognostic implication on resected non-small-cell lung cancer (NSCLC) patients. Formalin-fixed and paraffin-embedded tumour tissues resected from 69 NSCLC patients between stages I and IIIa were immunohistochemically examined to detect altered cyclin D1 expression. Twenty-four cases (34.8%) revealed positive immunoreactivity for cyclin D1. Cyclin D1 overexpression is significantly higher in patients with lymph node metastasis (50.0% vs 14.4%, P = 0.002) and with advanced pathological stages (I, 10%; II, 53.8%; IIIa, 41.7%, P = 0.048; stage I vs II, IIIa, P = 0.006). Twenty-four patients with cyclin D1-positive immunoreactivity revealed a significantly shorter overall survival than the patients with negativity (24.0 +/- 3.9 months vs 50.1 +/- 6.4 months, P = 0.0299). Among 33 patients between stages I and II, nine patients with cyclin D1-positive immunoreactivity had a much shorter overall survival (29.7 +/- 6.1 months vs 74.6 +/- 8.6 months, P = 0.0066). These results suggest that cyclin D1 overexpression is involved in tumorigenesis of NSCLCs from early stage and could be a predictive molecular marker for poor prognosis in resectable NSCLC patients, which may help us to choose proper therapeutic modalities after resection of the tumor.

Expression of cyclin D1 is correlated with poor prognosis in patients with areca quid chewing-related oral squamous cell carcinomas in Taiwan

Abnormal expression of cell cycle regulatory proteins, particularly cyclin D1, has been implicated in the pathogenesis of several types of cancer. We have examined the expression of cyclin D1 in histological sections of oral squamous cell carcinomas (SCCs) using anti-cyclin D1 antibodies with an immunoperoxidase technique. Cyclin D1 nuclear staining was observed in 73 of 88 (83%) cases of oral SCC. In 54 of these 73 (74%) cases, positive cyclin D1 staining was also found in the normal appearing epithelium immediately adjacent to the cyclin D1-positive SCCs. No significant correlation was found between the expression of cyclin D1 and the patients' age, sex, oral habits, cancer location and STNM status. The Kaplan-Meier analysis showed that patients with tumors containing more than 10% cyclin D1-positive cells had significantly shorter overall survival than those with tumors containing less than 10% cyclin D1-positive cells or with cyclin D1-negative tumors (P<0.05). Patients with positive lymph node status also had significantly shorter overall survival (P<0.01). These results indicate that cyclin D1 may play an important role in the genesis of oral SCC and may serve as an adjuvant marker of worse prognosis in patients with oral SCCs in Taiwan.

Prognostic role of cyclin D1 in lung cancer. Relationship to proliferating cell nuclear antigen

We developed an immunohistochemical assay specific for cyclin D1 and suitable for formalin-fixed and paraffin-embedded sections, to evaluate cyclin D1 expression in a group of 135 surgically resected lung-cancer patients for the purpose of investigating the prognostic role of this protein in lung cancer. In addition, we compared cyclin D1 expression with the expression of proliferating cell nuclear antigen (PCNA), considered to be a reliable index of the proliferation rate. We found cyclin D1 expressed in more than 60% of the neoplastic cells in 26.5% of our specimens. A total of 24.5% of the specimens showed cyclin D1 expression in a percentage of cells ranging from 30 to 60%; 36.7% of the specimens expressed cyclin D1 in less than 30% of the cells; and 12.2% of the specimens expressed cyclin D1 in less than 1% of the evaluated cells. Western blot analyses confirmed the specificity of this assay by correlating statistically in a highly significant fashion with the immunohistochemical results (P = 0.0003). Furthermore, we found a direct relationship between cyclin D1 and PCNA immunodetection (P = 0.0004), which correlated cyclin D1 overexpression with a higher tumor proliferation rate. When we analyzed our data statistically, cyclin D1 expression was found to be a negative prognostic marker (P < 0.00005) whose expression correlates with a shorter patient survival time.

Inhibition of cell proliferation in head and neck squamous cell carcinoma cell lines with antisense cyclin D1

Cyclin D1 and cyclin G are essential regulatory factors in the progression of the cell cycle from G0 through G1 and S phase. Aberrations in expression of these cyclins may lead to dysregulated cellular proliferation that could result in neoplasia. Amplification and overexpression of cyclin D1 have been observed in many human cancers, whereas cyclin G is a new cyclin recently described in osteosarcoma cells. This study was performed to determine whether these cyclins were amplified in head and neck squamous cell carcinoma (HNSCC) tumors. Polymerase chain reaction of DNA extracted from 22 HNSCC primary tumors and three HNSCC cell lines did not reveal amplification of cyclin D1 in any of the tumor samples. Southern blot analysis identified amplification of cyclin D1 in a single tumor. Amplification of cyclin G was not observed in any of the tumors by Southern blot hybridization with a cyclin G probe. HNSCC cell lines transfected with antisense cyclin D1 were tested for cell proliferation by the incorporation of 3H-thymidine into cells grown in serum-free media. By 72 hours of incubation, there was a greater than 30% reduction in proliferation of cells transfected with antisense cyclin D1 as compared with non-transfected control cells. The results indicate that cyclin D1 may play an important role in the growth and proliferation of HNSCC cells.

Characterization of the EMS1 gene and its product, human Cortactin

We have identified a novel gene, EMS1, that is consistently amplified and overexpressed in human carcinomas with an amplification of the chromosome 11q13 region. Comparisons of the EMS1 sequences with those present in the GenBank databases revealed a high identity with chicken cortactin. Southern and western blot analyses confirm the high sequence conservation during evolution. An antiserum specific for human cortactin, showed in gene transfer experiments that both human p80 and p85 isoforms are encoded by the EMS1 cDNA. Further comparisons demonstrated an high sequence and structural homology with HS1 that is implicated in signal transduction in lymphoid cells only. Expression of EMS1/cortactin mRNA was restricted to tumor cell lines derived from non-lymphoid origin. Cortactin contains (i) a filamentous actin binding tandem repeat domain, (ii) a proline-rich SH3-binding and (iii) a SH3 domain that is common in proteins involved in signal transduction. Our data suggest that human EMS1/cortactin has a function in signal transmission between cell-matrix contact sites and the cytoskeleton and, as such, its overexpression due to 11q13 amplification might effect adhesive properties of human carcinomas.

Genomic alterations in oral squamous cell carcinoma cell lines detected by two-dimensional gel analysis

To initially analyze the genomic abnormalities in human oral squamous cell carcinoma, DNA extracted from each of four oral carcinoma cell lines (Ca9-22, HO-1-u-1, HSC-2, KB) was examined using restriction landmark genomic scanning (RLGS), a method especially conducive to detection of amplifications and rearrangements of genomic DNA. Isolated cell line and normal oral epithial DNAs were sequentially cleaved with specific restriction enzymes, radiolabelled and separated in two-dimensional gel electrophoreses. Thirteen distinct fragments were commonly amplified in the oral cancer cell lines, six of which were evident in all samples. These results suggest genetic alterations characteristic of oral squamous cell carcinogenesis.

Amplification of int-2 and bcl-1 genes in squamous cell carcinoma of the larynx

We studied int-2 and bcl-1 gene amplification in 21 operated patients with cancer of the larynx. In 9 cases, the int-2 gene was amplified (42.9%) and in 4 cases. the bcl-1 gene was amplified (25.0%). Co-amplification of int-2 and bcl-1 was observed in three cases (18.8%), all of which were glottic carcinomas. Other amplified cases were supraglottic carcinomas. Tumor specimens with int-2 amplification were associated with a significantly worse prognosis. We suggest that int-2 amplification is one of the prognostic factors in laryngectomized patients with cancer of the larynx.

Nodal metastases: predictive factors

Squamous cell carcinoma of the upper respiratory and digestive tract has a high risk for neck metastasis, which reduces the probability of regional control and survival. We analyzed the literature and our own experience to review the possible risk factors for the occurrence of metastasis. The most significant risk factors were: tumor site and size, grade of histologic differentiation, tumor thickness (tongue and floor of mouth carcinoma), vascular embolization, and perineural infiltration. A series of biomarkers has been studied over the last 10 years, but no one has proved to be significant enough for clinical use. Based on several multivariate analysis, it is recommended elective treatment of the neck for high-risk patients.

Loss of heterozygosity in squamous cell carcinomas of the head and neck defines a tumor suppressor gene region on 11q13

Tumor suppressor genes APC, RB1, and DCC, as well as genes localized to 3p and 11q, have been implicated in the development of a number of human tumors. To determine whether allelic deletions occur at these loci in squamous cell carcinomas (SSCs) of the head and neck, 25 primary, 1 metastatic, and 3 recurrent tumors, along with the corresponding constitutional tissues, were analyzed by using a battery of polymorphic DNA markers. For two primary tumors, we also analyzed subsequent metastatic tumors of the lung. Polymerase chain reaction-based restriction fragment length polymorphism studies demonstrated loss of heterozygosity for the APC gene in 2 of 12 (17%), the RB1 gene in 5 of 22 (23%), and the DCC gene in 5 of 13 (38%) informative cases. Alleles on chromosomes 3p, 11q13, and 18q21.1 were lost in 7 of 20 (35%), 9 of 23 (39%), and 4 of 17 (24%) informative cases, respectively. A breakpoint was identified within the chromosomal region 3p13-21.2 in a SCC of the tongue. Breakpoints within 11q13 were identified in 2 additional tumors. Thus, allelic deletions of DCC, 3p, and 11q13 appear to be common in head and neck cancers, suggesting that these genes play a critical and complex role in the development of these tumors. Furthermore, the present study provides definitive evidence for a tumor suppressor gene at chromosome band 11q13 and localizes this gene to the INT2-D11S533 interval for future cloning and sequencing.

Cyclin D1 expression as a prognostic factor in advanced hypopharyngeal carcinoma

Hypopharyngeal carcinoma (HPC) has a poor prognosis. We investigated the expression of cyclin D1 in 34 advanced HPCs, and the value of cyclin D1 expression was evaluated as a predictive marker in terms of the prognosis of HPC, compared with other clinical factors. Using immunohistochemical staining, 20 of 34 patients showed positive immunoreactivity for cyclin D1. The statistical trend of the survival rate was lower in the cyclin D1-positive patients than in the cyclin D-negative ones (p = 0.0805). The predictive factors for the survival rate were effectiveness of neo-adjuvant chemotherapy (F = 8.698) (p = 0.0066), cyclin D1 expression (F = 6.244) (p = 0.0191) and N classification (F = 5.037) (p = 0.0335). The cyclin D1-positive patients had approximately four-fold higher mortality than the cyclin D1-negative ones. These data indicate that the expression of cyclin D1, in advanced patients with hypopharyngeal carcinoma is a useful marker for prognosis.

Amplification of 11q13 DNA markers in head and neck squamous cell carcinomas: correlation with clinical outcome

This study was performed on 282 patients with primary head and neck squamous cell carcinomas to evaluate the prognostic importance of 11q13 amplification. Amplification of the 11q13 DNA markers, HST-1/FGF-4 and BCL-1, evaluated by Southern and slot blot hybridisation, was detected in 52% of tumours. 11q13 amplification was associated with tumour site since this alteration occurred in 76% of tumours arising in the hypopharynx, versus 40% in the other sites (P = 0.0007). 11q13 amplification was also significantly related to the presence of involved neck lymph nodes (P = 0.013). The relationship between 11q13 amplification and risk of progression was studied in two subgroups of head and neck cancer patients with regard to treatment modalities. The presence of 11q13 amplification in the tumour was not significantly associated with a shorter event-free survival (P = 0.82) and crude survival (P = 0.61) of the 201 patients treated by surgery and postoperative radiotherapy. Similarly, absence of a relationship was observed for the group of 79 patients treated by surgery alone. These results confirm that 11q13 amplification is a prominent event in head and neck squamous cell carcinoma, indicating that it may be a common genetic event in the development of these neoplasms, but is not a reliable prognostic marker.

Assessment of chromosomal gains and losses in oral squamous cell carcinoma by comparative genomic hybridisation

Cytogenetic studies have demonstrated that oral squamous cell carcinomas (OSCCs) are usually characterised by complex karyotypes with many marker chromosomes. We analysed the genetic changes of six OSCC cell cultures by comparative genomic hybridisation (CGH). The CGH technique provides information on chromosomal gains and losses of the whole tumour genome in a single experiment and can therefore identify regions that harbour putative tumour suppressor genes (in the case of loss of chromosomal material) or oncogenes (in the case of gain or amplification of chromosomal material). Recurrent losses were detected at chromosome arms Xp and 3p (four cases). Gains consistently occurred at chromosome arms 8q and 9q (four cases) and at 1q, 3q, 5p, 7p, and 9p (three cases). The same six tumour cultures have previously been analysed by classical karyotyping. An important discrepancy between the two techniques was the number of losses detected: 55 with karyotyping versus 26 with CGH. On the basis of the cytogenetic complexity of these tumours and on FISH experiments that confirmed the CGH results, we conclude that genetic changes, particularly losses, can be more reliably detected by CGH analysis.

Cyclin D1 protein expression is related to clinical progression in laryngeal squamous cell carcinomas

The expression of cyclin D1 gene was investigated in 74 laryngeal squamous cell carcinomas (LSCCs) in order to determine its clinical and prognostic value. Overexpression of cyclin D1 was detected immunohistochemically using DCS6 monoclonal antibody on formalin-fixed, paraffin-embedded tissue sections. Cyclin D1 expression was detected in 22 of the 74 cases investigated (30 per cent), thirteen of which presented nodal metastases (59 per cent); of the patients without any detectable cyclin D1 protein expression, six presented nodal metastases (12 per cent). Cyclin D1 protein expression was found in five per cent of the specimens of normal mucosa, eight per cent of those with low-grade dysplasia and 20 per cent of those with high-grade dysplasia. A statistically significant association was found between cyclin D1 expression and the supraglottic site (p < 0.05), tumour extension (p < 0.001), the presence of lymph node metastases (p < 0.001), and advanced clinical stage (p < 0.001). Cyclin D1 expression analysis is an important tool in the selection of LSCC patients with an aggressive clinical course.

A new prognostic strategy for gastric carcinoma: mRNA expression of tumor growth-related factors in endoscopic biopsy specimens

OBJECTIVE

The study analyzed the prognostic value of the transcription of several tumor growth-related genes in gastric carcinoma biopsy specimens.

SUMMARY BACKGROUND DATA

The nodal status is one of the most significant prognostic factors in gastric carcinoma. There are, however, no satisfactory parameters for the preoperative assessment of nodal status.

METHODS

A reverse transcriptase-polymerase chain reaction analysis was used to analyze the transcription of several tumor growth-related genes in endoscopic biopsy specimens from 78 gastric carcinomas. The factors examined were cyclin D1, cyclin E, urokinase-type plasminogen activator, 72-kd type IV collagenase, vascular endothelial growth factor, platelet-derived growth factor-A (PDGF-A), transforming growth factor-beta, and interleukin-10. The relation between the mRNA expression and the clinical pathologic parameters was analyzed statistically.

RESULTS

The incidence of PDGF-A (p = 0.010) and transforming growth factor-beta (p = 0.009) mRNA expression increased as the pathologic stage advanced. Nodal metastasis correlated with cyclin D1 (p = 0.045), cyclin E (p = 0.037), urokinase-type plasminogen activator (p = 0.047), and PDGF-A (p = 0.003) mRNA. Interestingly, the expression of PDGF-A mRNA showed a positive correlation (p = 0.004) with the early presence of lymph node metastases.

CONCLUSIONS

Tumor growth-related factor mRNA in biopsy specimens may be a new prognostic tool.

Identification of seven differentially displayed transcripts in human primary and matched metastatic head and neck squamous cell carcinoma cell lines: implications in metastasis and/or radiation response

The patterns of differential gene expression were examined in two primary (A's) and two matched-metastatic (B's) head and neck squamous cell carcinoma (HNSCC) cell lines by differential display of mRNAs and northern blot hybridisation. Three cell lines used (PCI-04A, PCI-04B and PCI-06A) were established independently prior to therapy, whereas one cell line (PCI-06B) was established from a recurrent tumor after radiation therapy. A total of seven differentially displayed mRNA clones were identified, of which six clones were obtained by comparison of PCI-06A cells with PCI-06B cells (SCC-S1a/b, SCC-1c, and SCC-S2, PCI-06B; SCC-S3 to SCC-S5, PCI-06A), and one clone was obtained from the PCI-04A and PCI-04B match (SCC-Sa, PCI-04B). Based on the DNA database search for homology to the known sequences, six of the seven partial cDNA clones (SCC-S1a/b, SCC-1c, SCC-S2 to SCC-S4, and SCC-Sa may represent novel genes, whereas one cDNA clone (SCC-S5) shows significant homology to the HLA class II antigen gene (DPW2 beta chain). Each of the seven clones revealed preferential expression by northern blotting in the cell line of origin as compared to the matched counterpart. The transcripts ranged in size from approximately 7.0 Kb to 0.5 Kb. Interestingly, the SCC-Sa clone was preferentially expressed in both metastatic cell lines compared to the primary tumour-derived cell lines. We conclude that the SCC-Sa gene may be more commonly involved in tumour metastasis, whereas expression of the other genes (SCC-S1a/b, SCC-S1c, SCC-S2-SCC-S5) may be associated with metastasis and/or response of HNSCC to ionising radiation.

Comparison of DNA copy numbers in original oral squamous cell carcinomas and corresponding cell lines by comparative genomic hybridization

We analyzed regional DNA copy numbers in 4 oral squamous cell carcinomas (SCCs) by using comparative genomic hybridization, and compared them with those in cell lines derived from the SCCs. In the original tumors, DNA copy number increases were observed on chromosomes 5p (4/4 cases), 8q (4/4), 20p (3/4), 3q (2/4), 5q (2/4), 7p (2/4), 7q (2/4), 11p (2/4), 11q (2/4) and 13q (2/ 4). Although most of these changes have been described previously for SCC tumors in the head and neck, the incidence of increases in 8q and 20p was much higher in the present study; this may be important in relation to cell line establishment, since 8q contains e-myc, which is involved in immortalization. No common chromosomal region with DNA copy number decreases was observed, except for 18q (2/4). When the original tumors and the cell lines were compared, their profiles were essentially similar with one exception. Further, there was no region that commonly changed in the cell lines, but not in the original tumors, suggesting that the DNA copy number changes observed in the cell lines mostly represent those of the original tumors.

Overexpression of cyclin D1 correlates with early recurrence in superficial bladder cancers

Cyclin D1 is a cell cycle regulator essential for G1 phase progression and is frequently overexpressed in several human tumour types as a consequence of gene amplification or chromosomal rearrangements. We analysed the expression of cyclin D1 in 75 patients with transitional cell carcinoma (TCC) to investigate the possible relationship between its expression and clinical outcome as well as histopathological findings using the immunohistochemical method. We observed strong staining (++, > 50% positive cells) for cyclin D1 in 19 cases (25.3%) and weak staining (+, 5-50% positive cells) in 19 cases (25.3%). Overexpression of cyclin D1 was not associated with tumour invasion. No significant association was found between overexpression of cyclin D1 and tumour grade (P > 0.05). We assessed the differences of disease-free interval in superficial tumours and actuarial survival probability in invasive tumours according to the status of cyclin D1 expression. Tumours with (++) staining for cyclin D1 recurred much more rapidly than (-) and/or (+) staining tumours (P < 0.01 for - vs ++; P < 0.05 for + vs ++). However, overexpression of cyclin D1 was not associated with a shortened overall survival of patients with invasive tumours (P < 0.1). These results suggest that genetic alteration of cyclin D1 appears to be an early event in the tumorigenesis of bladder TCC and is associated with early recurrence in superficial tumours.

Morphological assessment of malignant potential of epithelial hyperplastic lesions

The spectrum of conventional and advanced morphological methods for the assessment of malignant potential of precancerous lesions of the laryngeal mucosa is discussed.