Page 120 - FINAL COMPENDIUM 2020-2021 27.2.2022

MONOAMINE OXIDASE A IS DOWN-REGULATED IN EBV-ASSOCIATED
NASOPHARYNGEAL CARCINOMA

Lee HM, Sia APE, Sathasivam HP, Chan MSA, Rajadurai P, Tsang CM, Tsao WS, Murray P, Tao Q, Paterson I, Yap LF
Introduction: Nasopharyngeal carcinoma (NPC) is a highly metastatic cancer that is
consistently associated with Epstein-Barr virus (EBV) infection. Materials and methods:
In this study, we identify for the first time a role for monoamine oxidase A (MAOA) in NPC.
MAOA is a mitochondrial enzyme that catalyses oxidative deamination of
neurotransmitters and dietary amines. Depending on the cancer type, MAOA can either
have a tumour-promoting or tumour-suppressive role. Results: 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. Conclusion: 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.

Published in Sci Rep 10, 6115 (2020). https://doi.org/10.1038/s41598-020-63150-0
Dr Hans P Sathasivam AP Anna Chi Man Tsang
Institute for Medical Research School of Biomedical Sciences and Center for Cancer
National Institutes of Health Research
Ministry of Health, Malaysia Li Ka Shing Faculty of Medicine
The University of Hong Kong
Prof. Dr Ian Charles Paterson Shatin, Hong Kong
Dr Lee Hui Min Department of Anatomical and Cellular Pathology and
Dr Alice Pei Eal Sia State Key Laboratory of Translational Oncology
AP Dr Lee Yap Fah The Chinese University of Hong Kong
Department of Oral and Craniofacial Sciences Pokfulam, Hong Kong
Faculty of Dentistry, University of Malaya
Kuala Lumpur, Malaysia Prof. George Sai Wah Tsao
School of Biomedical Sciences and Center for Cancer
Dr Lili LI Research
Cancer Epigenetics Laboratory Li Ka Shing Faculty of Medicine
Department of Clinical Oncology The University of Hong Kong
State Key Laboratory of Translational Oncology Shatin, Hong Kong
Sir YK Pao Center for Cancer and Li Ka Shing Institute of
Health Sciences Prof. Paul Murray
The Chinese University of Hong Kong Health Research Institute
Shatin, Hong Kong University of Limerick, Limerick, Ireland
Institute of Immunology and Immunotherapy
Dr Melissa Sue Ann Chan University of Birmingham, Birmingham, United Kingdom
Department of Oral and Craniofacial Sciences
Faculty of Dentistry, University of Malaya Prof. Qian Tao
Kuala Lumpur, Malaysia Cancer Epigenetics Laboratory, Department of Clinical
Oncology
Prof. Dr Pathmanathan Rajadurai State Key Laboratory of Translational Oncology
Sime Darby Medical Centre Subang Jaya Sir YK Pao Center for Cancer and Li Ka Shing Institute of
Subang Jaya, Malaysia Health Sciences
The Chinese University of Hong Kong
Shatin, Hong Kong

96