Journal of International Dental and Medical Research ISSN 1309-100X Gene Polymorphism in Head and Neck Cancer http://www.jidmr.com Nadhira Haifa and et al Volume ∙ 13 ∙ Number ∙ 3 ∙ 2020 Page 1174 MDM2 SNP309 T>G Gene Polymorphism in Head and Neck Cancer in an Indonesian Population Nadhira Haifa 1 , Yurnadi Hanafi Midoen 2 , Nurtami Soedarsono 3 , Angger Waspodo Dias Adrianto 4 , Elza Ibrahim Auerkari 1* 1. Undergraduate Dentistry Study Program, Faculty of Dentistry, Universitas Indonesia, Jakarta, Indonesia. 2. Department of Medical Biology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia. 3. Department of Oral Biology, Faculty of Dentistry, Universitas Indonesia, Jakarta, Indonesia. 4. Postgraduate Odontology Forensic Program, Faculty of Dentistry, Universitas Indonesia, Jakarta, Indonesia. Abstract Murine double minute 2 (MDM2) is a negative regulator of the tumor suppressor p53. Studies have reported that the MDM2 SNP309 T>G polymorphism increases the susceptibility to head and neck cancer (HNC). In particular, the GG genotype of SNP309 in the MDM2 promoter region was found to increase the affinity of the Sp1 transcription factor, leading to higher levels of mRNA and MDM2 protein, thereby reducing the activity of p53 and potentially promoting the development of cancer. This study was conducted to compare the status of the polymorphism in 50 patients with HNC and 50 healthy individuals among an Indonesian population using the polymerase chain reaction- restriction fragment length polymorphism technique. Statistical analysis using Fisher’s exact test was performed to analyze the significance of the observed differences in frequencies between the two groups. Results demonstrated the presence of all genotype variants of the polymorphism, but there were no significant differences in the genotype or allele frequencies between patients with HNC and healthy individuals among the tested Indonesian population. Clinical article (J Int Dent Med Res 2020; 13(3): 1174-1177) Keywords: Genetic polymorphism, MDM2 SNP309 T>G, head and neck cancer. Received date: 10 January 2020 Accept date: 15 March 2020 Introduction Cancer is one of the most common causes of death in the world, with approximately 14 million cases and 8.2 million deaths reported every year. 1 The incidence of cancer has been estimated to increase by up to 70% in the next two decades. 2 In Indonesia, the prevalence of cancer has been reported to be 1.4% among all age groups. 3 Head and neck cancer (HNC) generally occurs in the upper aerodigestive tract, such as the oral cavity (40%), the pharynx (15%), the larynx (25%), and the adjoining tissues such as the salivary glands (20%). 4 HNC has been found to be more frequent in men than in women (2:1 to 4:1). Its prevalence in Indonesia is high, ranking the fourth position among all malignancies. The most frequent type is squamous cell carcinoma, representing >90% of the cases. 5 Although smoking and drinking are the primary carcinogenic risk factors associated with HNC, there is also a genetic component in the etiology. 4,6-8 Single nucleotide polymorphisms (SNPs) represent the most common type of human genetic variation and affect a single nucleotide, with a frequency >1% in humans. Some SNPs have been found to be risk factors for cancer. 9,10 Yu et al. (2011) reported that the GG genotype causes an increase in the levels of the protein murine double minute 2 (MDM2), a decrease in p53 levels, and a decrease in apoptosis (which depends on the p53 command) in response to DNA damage. Overexpression of MDM2 can also be involved in the downregulation of other important cellular proteins that can promote carcinogenesis. 11 Yu et al. (2011) conducted a study on HNC using 1083 samples of patients with squamous cell carcinoma head and neck (SSCHN) and 1090 cancer-free control subjects and found no significant difference in the *Corresponding author: Elza Ibrahim Auerkari Department of Oral Biology Faculty of Dentistry, Universitas Indonesia E-mail: elza.ibrahim@ui.ac.id