Monoamine oxidase A is down-regulated in EBV-associated nasopharyngeal carcinoma

• Main Authors: Lee, Hui Min, Sia, Alice Pei Eal, Li, Lili, Sathasivam, Hans Prakash, Chan, Melissa Sue Ann, Rajadurai, Pathmanathan, Tsang, Chi Man, Tsao, Sai Wah, Murray, Paul G., Tao, Qian, Paterson, Ian Charles, Yap, Lee Fah
• Format: Article
• Language: English
• Published: Nature Research 2020
• Subjects: Practice of dentistry. Dental economics
• Online Access: http://eprints.um.edu.my/25008/1/Monoamine%20oxidase%20A%20is%20down-regulated%20in%20EBV-associated%20nasopharyngeal%20carcinoma.pdf; http://eprints.um.edu.my/25008/; https://www.nature.com/articles/s41598-020-63150-0

Nasopharyngeal carcinoma (NPC) is a highly metastatic cancer that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we identify for the first time a role for monoamine oxidase A (MAOA) in NPC. MAOA is a mitochondrial enzyme that catalyzes oxidative deamination of neurotransmitters and dietary amines. Depending on the cancer type, MAOA can either have a tumour-promoting or tumour-suppressive role. We show that MAOA is down-regulated in primary NPC tissues and its down-regulation enhances the migration of NPC cells. In addition, we found that EBV infection can down-regulate MAOA expression in both pre-malignant and malignant nasopharyngeal epithelial (NPE) cells. We further demonstrate that MAOA is down-regulated as a result of IL-6/IL-6R/STAT3 signalling and epigenetic mechanisms, effects that might be attributed to EBV infection in NPE cells. Taken together, our data point to a central role for EBV in mediating the tumour suppressive effects of MAOA and that loss of MAOA could be an important step in the pathogenesis of NPC.