IncIdence of HPV InfectIon In oral SquamouS cell carcInoma and ItS aSSocIatIon wItH tHe PreSence of P 53 & c-myc mutatIon : a caSe control Study In muwardI HoSPItal Surakarta

Introduction: Annual incidence rates for oral and pharyngeal cancer are estimated at 25 cases per 100,000 in developing countries. Human papilloma virus (HPV) was implicated in pathogenesis of Cancer. The mutations of p53 and c-myc are found 50% in cancer. objective: Aims of this research were to know the incidence of OSSC patient which realized HPV infection without p53 and c-myc gene mutation. materials and methods: Tissue biopsy frozen sections were taken from BOSC (Benign Oral Squamous Cell) and OSCC (Oral Squamous Cell Carcinoma) patients collected from Oral and Dental Departement of dr Muwardi Distric Hospital in Surakarta from January 2007 to January 2008. To amplify L1-HPV gene for fixed the HPV stressor. To amplify p53 and c-myc genes, continued with SSCP (Single Strand Conformational Polymorphisme) analysis and followed with measurement using densitometer, to see mutation existence. The collected data were analyzed with Chi Square. results: BOSC patient identified 23% with HPV infections and OSCC patient identified 73% with HPV infections. Hundred percent BOSC patient with HPV infection without mutation in p53 gene and c-myc gene, 81% OSCC patient with HPV infection without mutation in p53 gene and 91 % OSCC patient with HPV infection without mutation in c-myc gene. Chi Square analysis showed significant difference between BOSC and OSCC patients with HPV infection without mutation in p53 and c-myc gene. conclusion: HPV is a factor for pathogenesis of OSCC.


Introduction
Update research found that cancer is widely perceived as a heterogeneous group of disorders with different biological properties, are caused by a series of clonally selected genetic changes in tumour-suppressor genes and oncogenes. 1,2However, recent data suggest that cancer has a common basis that is grounded in a polyclonal epigenetic disruption of progenitor cells, mediated by tumour-progenitor genes.Tumour cell heterogeneity is due in part to epigenetic variation in progenitor cells and epigenetic plasticity together with genetic lesions drives tumour progression.This crucial early role for epigenetic alterations in cancer is in addition to epigenetic alterations that can substitute for genetic variation later in tumour progression. 2,3Therefore, non-neoplastic but epigenetically disrupted might be a crucial target for cancer risk management.
Cause of cancer can divide into two groups: environmental cause and hereditary genetic cause.Cancer is primarily an environmental disease, though genetics influence the risk of some cancers.Environmental factors include: environmental pollutants, diet and obesity, tobacco, infections, radiation, and lack of physical activity.These environmental factors cause or enhance abnormalities in the genetic of cells. 3The prevalence of oral cancer is increase in Africa.Annual incidence rates for oral and pharyngeal cancer are at 25 cases per 100,000 in developing countries.The urbanisation and increasing access to, and utilisation of tobacco in its various forms as well as alcohol, is to an increase in the incidence of oral cancer. 4Epidemiology of oral cancer are squamous cell represents 90% of oral cavity tumours, the incidence was increases with age (represent 3% of cancers in men and 2% of cancers in women). 5Factor that implicated as a potential cock and or promoter cancer were tobacco, alcohols, radiation of sunrise, ionization radiation, carcinogen related work, environment pollutant, medicines, nutrition and infectious agent.Another stressor is life in village, social-economic factor, age, genders and response immune mechanism.The followed factor is periodontal disease chronic, bed oral hygiene, diseases of tooth, sharp of set teeth, electrogalvanism and edentulism.Another researcher found that human papilloma virus (HPV), implicated in Oral Squamous Cell Carcinoma (OSCC) pathogenesis. 3,6,7Therefore, if the pathogenesis of OSCC can't be explained so the morbidity and mortality can increase and lead to decrease the human resources.
The role of HPV, expression of E6 and E7 protein virus, expression of p53 and c-myc proteins host can explained by pathobiology examination 8,9 in cell perception and cell response concept.The binding of E6 protein of HPV with p53 proteins lead to decrease the apoptosis.
The other hand binding of E7 proteins with pRb protein lead to activate c-myc protein expression so be impact in decreases the proliferation.The mutations of p53 and c-myc are not found. 10,11,12This concept gives a chance to explain the increasing OSCC.
In the disease of high risk HPV infection explained the viral genome integrates into the host genome which is the necessary event for the keratinocytes immortality.
During this process of integration the circular form of viral genome breaks at the level of the E1 and E2 regions.
Different studies have shown that the integrated part of the genome corresponds to E1, E6 and E7.The loss of E2 during this process of integration produces the loss of E6 and E7 control.Therefore, the sequences E6 and E7 are directly involved in the cellular cycle by inhibiting the normal functions of p53 and pRb.The p53 can provoke the arrest of cellular division and assure the time necessary for DNA repair.If damage can't be repaired, p53 is able to induce the apoptosis and prevent the propagation of DNA damage in subsequent generations of cells.In the case of other types of tumours, p53 is usually mutated and acts as a real oncogene.In the case of HPV infection, E6 suppresses the properties of p53 gene product achieving the functional equivalent of the two hits required to knock out both alleles of a tumour suppressor gene.The mutations of p53 are normally not found.The E7 protein interacts with retinoblastoma protein (pRb), which is the crucial factor for the cellular cycle control.This interaction causes the release of the transcription factor E2F, which is now free to act and can stimulate the cellular division.E6 and E7 can cooperate with cellular oncoproteins like ras and myc which enables the virus to act at the level of growth factors and cellular and nuclear metabolism producing oncogenic cells.E6 and E7 can provoke directly DNA mutations of the host cell.This means that certain types of HPV are able to cause malignant lesions even without the action of other cofactors. 13

materials and methods
Fourty frozen section BOSC tissue and fiveteen frozen section OSCC tissue patients collected from Oral and Dental Clinic of dr Muwardi Distric Hospital in Surakarta from January 2007 to January 2008.Parrafin blocks were made from cutting I, which was subsequently stains with Haematoxyline Eosine (HE) to ascertain the type of neoplasm.
Cutting II was subjected to Deoxyribonucleic Acid (DNA) isolation was made by Henk Schmits method with some modifications.Cut up to 25 mgr of tissue into small pieces, place in 1. Chi Square analyze showed have significant differences between BOSC and OSCC patients with HPV infection without mutation in p53 and c-myc gene ( discussion Dental caries and periodontal disease are generally considered to be the major oral health problems around the world.In developing countries of Africa, these appear to be neither as common nor of the same order of severity as in the developed world.An epidemiological description of a given health problem usually includes its prevalence, severity (morbidity, mortality) and ageadjusted distribution in the population.Oral diseases known to exist in each community must be assessed in this way in order to develop programmes appropriate to community needs.Based on this form of analysis, the most prominent oral health problems in Africa amongst low socio-economic communities include Noma, ANUG (Acute Necrotising Ulcerative Gingivitis), oral cancer, the oral manifestations of HIV and AIDS, orofacial trauma, and dental caries.Studies have shown that the oral manifestations of HIV/AIDS are common.Candida infections, necrotizing gingivitis and oral hairy leukoplakia are the most common.The prevalence of oral cancer is also on the increase in Africa.Annual incidence rates for oral and pharyngeal cancer are estimated at 25 cases per 100,000 in developing countries.The rapid urbanisation and increasing access to, and utilisation of tobacco in its various forms as well as alcohol, is leading to. 16So the main risk factors are tobacco abuse, smokers represent 90% of oral cancer patients.Other risks that under research are viral infection like HSV and HPV. 5,6,17,1853 is a gene that codes for a protein that regulates the cell cycle and hence functions as tumor suppression.It is very important for cells in multicellular organisms to suppress cancer.P53 has been described as the guardian of the genome, referring to its role in conserving stability by preventing genome mutation.The name is due to its molecular mass: it is in the 53 kilodalton fraction of cell proteins.The human p53 gene is located on the seventeenth chromosome (17p13.1).It plays an important role in cell cycle control and apoptosis.Defective p53