Abstract 3556: Alcohol-dysregulated non-codingRNAs in the pathogenesis of oropharyngeal cancer
Authors: Saad Maarouf A. , Kim Elizabeth , Yu Vicky , Ku Jonjei , Kuo Selena Z. , Zheng Hao , Rahimy Elham , Wang-Rodriguez Jessica , Ongkeko Weg M. 
Published: May 2015

Though alcohol consumption has been implicated in the pathogenesis of oropharyngeal cancer, the molecular mechanism for the pathogenesis of alcohol-related oropharyngeal cancer is poorly understood. In our study, we sought to identify key microRNAs (miRNA), piwi-interacting RNAs (piRNA), and long non-coding RNAs (lncRNA) dysregulated by ethanol, as well as its known carcinogenic metabolite acetaldehyde, to determine the role these non-coding RNAs (ncRNA) play in the pathogenesis and progression of oropharyngeal cancer. Using next generation sequencing analysis, we analyzed the non-coding RNA of head and neck squamous cell carcinoma (HNSCC) patients. In order to further investigate these ncRNAs, we exposed a panel of normal oral epithelial cell lines (OKF4, OKF 6) to 0.1%, 0.3%, and 1.0% ethanol for 4 weeks to represent social drinkers, moderate drinkers, and heavy drinkers respectively, and performed qPCR arrays to determine alcohol regulation of piRNAs and lncRNAs in vitro. We identified a panel of 5 piRNAs, 6 lncRNAs, 8 miRNAs and that were dysregulated consistently in vitro and clinically between alcohol drinkers and those who are non-drinkers. The five piRNAs (piR 25894, piR 35373, piR 266308, piR 34946, and piR 58510) were upregulated between parental cells and the alcohol-treated derivatives in both clinical and in-vitro data, and further investigation may elucidate their role as oncogenes. SAF and Zeb2Nat, two lncRNAs implicated in oncogenesis, exhibited the highest fold change, and the stem cell genes Nanog and Oct-4, and the epithelial-to-mesenchymal transition (EMT) gene Vimentin, were also upregulated through ethanol treatment, thus suggesting that SAF and Zeb2Nat are important in the pathogenesis of alcohol-induced oropharyngeal cancers by promoting expression of the EMT phenotype and stemness. Ectopic expression of miR-30a-5p and miR-934 resulted in increased expression of the stem cell genes, CD44, Oct3/4, Nanog, BMI-1. Forced expression of these miRNAs also resulted in increased proliferation, increased invasion, and inhibition of cisplatin-induced apoptosis, signifying the malignant transformation of normal oral cells. Identification of key ncRNAs differentially expressed in alcohol-related oropharyngeal cancer may reveal important steps in the initiation and progression of oropharyngeal cancer. These key ncRNAs may also serve as indicators and therapeutic targets for more effective treatments of alcohol-associated oropharyngeal cancer.

Citation Format: Maarouf A. Saad, Elizabeth Kim, Vicky Yu, Jonjei Ku, Selena Z. Kuo, Hao Zheng, Elham Rahimy, Jessica Wang-Rodriguez, Weg M. Ongkeko. Alcohol-dysregulated non-codingRNAs in the pathogenesis of oropharyngeal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3556. doi:10.1158/1538-7445.AM2014-3556