Abstract 3437: Differential transcript expression in nasopharyngeal carcinoma by cDNA microarray analysis

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA By cDNA microarray, expression profiling was carried out in 360 paired tumor & normal biopsies from 60 nasopharyngeal cancer (NPC) patients at 3 time points, namely, at diagnosis of NPC, on treatment with an anti-inflammatory drug, Celecoxib (Celec) and on radiotherapy (RT). We found 1 cluster of 82 transcripts with statistically significant difference in expression between tumor & normal tissues at diagnosis, a second cluster of 214 tumor versus normal transcripts on Celec treatment and finally a third cluster of 202 tumor versus normal transcripts on RT. Differential expression of selected tumor associated transcripts was confirmed by RT-PCR. These include 8 tumor up-regulated transcripts with 3 encoding for immunological/inflammatory molecules, IL8, CXCL9 & CXCL10, 1 matrix metallopeptidase, MMP12, which break down extracellular matrix and thus is associated with cancer metastasis, 1 osteonectin protein which is involved in cell shape changes and thus related to cancer invasion, SPARC, 1 bone morphogenic protein with a role in tissue differentiation, GREM1, 1 GTPase-activating protein for phorbol ester receptor, CHN1 and a sorting nexin family member with a role in intracellular trafficking, SNX10. Genes which were prominently down-regulated in tumor were a variety of polymorphic xenobiotic detoxification enzyme genes or genes with antioxidant function (e.g. GSTA1, GSTA2, GSTA3, CYP4B1, ALDH1A1, ADHFE1, MAOB, NQO1 & OAT) which can detoxify carcinogens or other harmful chemicals or have anti-oxidant effects. Many genes were also down-regulated by RT in tumor tissues and one notable example was TOP2A which encodes topoisomerase 2A involving in chromosome condensation & chromatid separation during DNA replication, CLDN1 which has tight junction adhesion function, ANLN which is required for cytokinesis, and STMN1 which can regulate microtubule filament. These genes had good potential in applying for clinical applications in diagnosis or treatment of NPC in the future. Further exploration of the clinical applications of these genes is underway. Citation Format: Timothy T.C. Yip, Dora L.W. Kwong, Roger K.C. Ngan, Cadmon K.P. Lim, Wai Wai Cheng, Victor W.S. Ma, Stephen C.K. Law, Loretta Tse. Differential transcript expression in nasopharyngeal carcinoma by cDNA microarray analysis. [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 3437. doi:10.1158/1538-7445.AM2014-3437