P.44 Examination of genetic expression profilesof oral cancer in the context of biological pathways

158

Poster Sessions

dippers, and 2 mixed. For Norway, ~ m o r s formed groups based on anatomical sites [larynx/tongne (predominantly of grade I-II), gingival/floor of mouth/buccal mucosaJhard palate (predominantly of grade III-IV)]. Quantitative RT-PCR for specific genes and lo cahzation o f protein products by tmmunohistochemastry validated the mlcroarray-based data. Conclusion: Our study has identified a subset of 73 genes diftbrentially expressed in O/HNSCCs from Sudan and Norway. This may contribute to an maproved understanding of the molecular change(s) during development of this pathology, suggesting involvement of 73 genes m these tumors regardless of the ethnic differences/or other hfe style risk factors between patients from the two cousitries. Findings might further provide the potential for further investigations of these genes as diagnostic, prognostic Nomarkers and/or targets for therapy m studies involving cases of O/HNSCCs from the Sudan and Norway.

~Loss of heterozygosity on chromosome 2q in human oral squamous cell carcinoma H. Nurnasawa, N. Yamamoto, T. Shibahara. The F~rst Department of Oral and MaxffIofac~al Surger): Tokyo Dental College, Japan Introduction: Loss of heterozygosity (LOH) correlates with

reactivate tumor suppressor gene. The aim of this study was to evaluate the role of chromosome 2q deletions m human oral squamous cell carcinoma (SCC) progression, to define the precise location of putative tumor suppressor genes, and to see af LOH on this chromosome arm correlated with a poor prognostic factor m oral SCC. Materials and Methods: We analyzed chromosome 2q for LOH in 65 primary oral SCCs and 10 lymph node metastatic turnors from 65 patients using 10 markers and constructed a deletion map for tins chromosome arm. A subject has a checkup m Tokyo Dental College oral surgery, and at is DNA provided from tumor tissue and normal tissue of 65 dlagnnosed as oral squamous cell carcu~oma. Results: We have found 3 distract putative tumor suppressor locl at 2q. The high frequently deleted regions were identailed an D281328 (21.3°5), D281327 (22.6°,5), and D2S206 (30.1%) at 2 q 1 4 ~ 1 , 2q32 35, and 2@6 PCR-LOH assay on 10 metastatic tumors indicated interesting results. Four regions, D2S436, D2S1327, D2S155, and D28164, had high frequencies of LOH, 50%, 22.2%, 50%, and 50%, respectively. As a result of having reviewed the result about a chmcal factor and presence of tnstopathologlcal factor and LOH/MSI, frequent deternunataon of LOH was recogmzed than early cancer of progressive cancer. The number at more than two LOH loci was sagnlficas~t with a poor prognosis at 2q (p 0.025). Conclusion: These findings demonstrate that oral SCC exhibits genetic alterations at multiple loci and that allehc loss at more than two locations as indicative of a poor prognosis. Tins is the first study to demonstrate the prognostic slgmficance of LOH at 2q for oral cancer and may help to identify patient who should receive more aggressive treatment.

P.431 Cytogenetic support for field cancerization in the oral cavity C. Marchetti, M. Maffione, L. Montebugnoli, A. Cuppini, M.P. Foschini, A. Farnedi, E. Magrini, A. Pession. 1Department

of OraI Sczence. Umvers~ty of Bologna, Italy, :Department of Oncological Sciences, Section of Anatomic Pathology, University of Bologna at Bellaria Hospital, Baly Introduction: Field casicerization and rmcrometastatic lesions have been proposed as competing concepts to explain the high incidence of second primary tumors in patients with oral squamous cell carcinoma (OSSC). The field cancerization theory is based on the assumption that a stem cell acquires a genetic alteration m the lmtial phase, forming subsequently a patch, winch converted into an expanding f e l d as a result of additional genetic alterations, and replaces the normal epithehum over a wide diameter. The premise of this theory is the lack of clonal relationship between multiple lesions. The area of the present study was to investigate whether the normal mucosa m a patient with OSCC is already affected by genetic changes and share common chromosomal alterahons with the mahgnant lesion. Materials and Methods: Multiple biopsies were performed in a patient with OSCC, reside the ~u~lor, In the adjacent normal nmcosa and in normal mucosa from the opposite site of the oral cavity. All specimens underwent lmmunohlstochetmcal as~alysls for quantification of p53 and KI67 expression and cytogenetic analysis by G binding on short term cultures. Results: Overexpression of KI67 and p53 was found either reside tumor or In basalJsuprabasal layers from normal adjacent nmcosa or m normal mucosa distant from the tumor. Cytogenetlc asmlysls of OSCC gave the following results: 46, XY, del(16q)[4]; 45M8, X, }, del(16q)[cp6]; 46, XY[4], while m normal mucosa: 46-47, XY, del( 16q)[cp4]: 47, XY, +Y[2]; 46, XY[9]. Conclusion: The normal epithehum an our patient with OSCC showed abnormal overexpression of cycle related and regulatory markers as well as clonal cytogenetic alterations even m zone very distant from tumor. Since the chromosomal alterations were only partially (deletion of 16q) shared by primary tumor, the present case report ~s In agreement with the theory of field cancerization in OSSC.

I•

Examination of genetic expression profiles of oral cancer in the context of biological pathways

C. Chen, E Choi. ;Fred Hutchinson Cancer Research Center, Seattle, ~l~shmgton, USA, 2Umvers~ty Qf I~,hmgton, Seattle, l~,hmgton, USA Introduction: Squamous cell carcinoma of the oral cavity and

oropharynx (O8CC) is associated with considerable mortahty and morbidity and is a major public health concem worldwide. To date, 23 studies incorporating DNA rmcroarray analyses have examined genome-wide genetic expression changes associated with the development of OSCC. Materials and Methods: We identified pubhshed reports of genetic expression profiles of OSCC by PubMed search. We performed a review of the reports to identify genes that have been repeatedly fotlnd to exhibit substantially altered expression in OSCC, compared to controls. We then determined whether genes with aRered expression belong to defined biological pathways, using GenMapp 2.0 software. Results: The genes that were most corimaonly found to exhibit altered expression were those encoding for cytoskeleton and extracellular matrkx proteins, H~ari~natory mediators, proteins involved in epidermal differentiation, and cell adhesion

Epidemiology. Education, Health economics, Staging and prognosis molecules. Results of GenMapp 2.0 analysis suggested global down-regulation o f genes that encode for ribosomal proteins and enzymes in the cholesterol biosynthesis pathway; and uprega~lation o f genes that encode for matrix metalloproteinases and genes that bear on inflammatory response. Conclusion: Our review mchcates that there are a number of genes whose expression extnbits substasitlally altered expression in cancerous versus non-cancerous states across studies. Analysis of pooled gene expression changes using GenMapp 2.0 software revealed members of several dislinctive pathways to be simultmleously down- or up-regulated.

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Multiple mutations of the p53 gene of salivary duct carcinomas (SDC) correlate with a more aggressive clinical outcome

J.D. Schepers, K. Roser, M. Jaetme, Th. Lonmg. Insmute

of Oral Pathology, Untverstty Hospttal Hamburg-Eppo~dorZ Hamburg, Germany Introduction: P53 over-expression which is observed preferentially 112high grade carcinomas of salwary glands as detectable m up to two t t ~ d s of SDC cases. The cltmcal course of these tumours is characterlsed by extended local dasease, early distant metastasis and poor outcome. Materials and Methods: 38 cases of SDC collected from the Sahvary Gland Register of the Ulnverslty of Hamburg were analyzed for p53 expression by lmmuno-hlstochelnlstry and for nmtations an p53 by temperature gradaent gel electrophoresis (TGGE), and subsequently the results were correlated to clinical data. Ilnmunotnstochelmcal exanlmatlons were performed with a monoclonal antibody raised against p53. Inimmaostaming was achieved by using the ABC method. Genonalc DNA was extracted from paraffin embedded tissue samples and DNA f r a ~ l e n t s comprising exons 5 - 8 of the p53 gene and adjacent lntron sequences were amphfied. Subsequently the purified PCR-products were loaded on a horizontal 8°6 polyacrylannde gels and run under d e n a ~ r m g condatlons with different temperature gradients and tunes depending on the exon to be analysed. Results: Irnmunotnstochemastry revealed p53 protean expression an 87% of the turnors. 55°6 extnblt a weak nuclear staining (+), whereas 31°'o were classified as me(hum and strongly positive (+% +++). All samples selected for mutation analysis were screened by TGGE to detect mobthty shifts. The electrophoretlcal pattern was altered m 66% of the cases suggesting the presence of a p53 mutation. In 13 cases, more than one mutation was found m the same sample. Conclusion: In comparison to chnlcal parameter a correlation could be demonstrated between p53 expression and metastazatlon, tumor recurrence and over-all survival. Patients with strong p53 lmmunoreactlvlty and with more than one niutatlon m the p53 gene show the more aggressive course of @sease, especially expressed m their tendency to develop dastasit metastases.

159

Epidemiology, Education, Health economics, Staging and prognosis

[P•]

Oral cavity cancers in young age: analysis of patient, tumor and treatment characteristics in Chiang Mai University Hospital

I. Chitapanaru_x I , R Sittitrai 1, E. Tharavlchltkul I , E Kanmerdsupaphon ~, T. Pattarasakulchal 1, E Srluthalslrlwong 2, V. Sulahomya 2, V. Lorvidhaya 2.

:Division of Therapeutic Radiology and Oncology Faculty of Medteme, ChtangMat UnmerstO: Thatland, :Department of Otolarvngology Faculty of Medmme, ChtangMat Unmerstty, Thatland Introduction: Oral cavity cancer is predominantly a (hsease o f nalddle-aged nlen who use tobacco and alcohol. Nearly 95% o f carcmonias occur after the age of 45, with an average age o f 60 years. In recent years, oral cavaty cancers have increased in younger age, especially m female who never consumed alcohol or smoked. The purpose of this study is to provide all the H£ormatlon of these cancers m young age treated m our hospital during 5-year period. Materials and Methods: We reviewed the mechcal records o f oral cavaty cancers pataents occur before the age of 45 who treated at Chaang Mal Umversaty Hospital from 1 9 9 9 ~ 0 0 3 . All the demographic data, hlstopathology, treatment modahtles and their resuRs were recorded. Results: Follow up range from 0.7 to 4.4 years (mean 2.6 year).A total of 20 patients were stuched. There were 12 male (60%) mad 8 female (40%). The mean age was 34.4 year (20 40 year). The most common site was oral tongue (15 patients, 75%) followed by hard palate (3 patients, 15%), lower gum (1 patient, 5°4), and floor of mouth (1 patient, 5%). There were 18 cases (90°4) of squamous cell carcinoma, and 2 cases (10°4) of non-Hodgkln lymphoma. Fifty-five percent o f patients were stage III and IV. Only 1 patient (5%) was treated by surgery alone, 13 palaents (65%) were treated by surgery and post-operative radlotheraw, 4 patients (20°,3) were subjected to radiotherapy alone, and 2 pahents (10%) were treated by chemotherapy pins radiotherapy. Five patients (25%) developed loco-reglonal recurrence of disease within 10.8 months (2 to 36). Four patients (20°4) have persistent disease. Dlstasit metastases were found m 1 patient (5%) and 10 patients (50%) had no evidence of disease at the time of analysis. Conclusion: The demographic data o f oral cavity m younger age m our hospital were different from the elderly with commoitly occurred m oral tongue. Most of the patients were locally advanced stage. The results of all lxeatuient modahties provided fair loco-reglonal control suggested more aggressive treatment Ln this group of patient.

Epithelial dysplastic features independently 1•71 associated with AgNOR count A. Chattopadhyay, J.G. Ray. Temple Umoer~ty School of

Denttst~3: Phdadelphta. USA Introduction: Some studies have suggested usefulness of silver stainable nucleolar organizer region (AgNOR) analysis as a simple way to quantify epithelial dysplasla (ED) m oral leukoplal~a. The key piece of evidence, that is trussing, m this aspect would be to denlonstrate that AgNOR counts are associated with presence/absence of dysplastlc features seen under the microscope not demonstrated by any published study