An indicator of cancer: downregulation of Monoamine Oxidase-A in multiple organs and species

Leszek A Rybaczyk¹ , Meredith J Bashaw² , Dorothy R Pathak³ and Kun Huang¹^,4

¹Department of Biomedical Informatics, The Ohio State University, Columbus, OH, USA

²Department of Psychology, Franklin and Marshall College, Lancaster, PA, USA

³Departments of Epidemiology and Family Medicine, Michigan State University, East Lansing, MI, USA

⁴Comprehensive Cancer Center Biomedical Informatics Shared Resource, The Ohio State University, Columbus, OH, USA

author email corresponding author email

BMC Genomics 2008, 9:134doi:10.1186/1471-2164-9-134


Published:	20 March 2008

Abstract

Background

Identifying consistent changes in cellular function that occur in multiple types of cancer could revolutionize the way cancer is treated. Previous work has produced promising results such as the identification of p53. Recently drugs that affect serotonin reuptake were shown to reduce the risk of colon cancer in man. Here, we analyze an ensemble of cancer datasets focusing on genes involved in the serotonergic pathway. Genechip datasets consisting of cancerous tissue from human, mouse, rat, or zebrafish were extracted from the GEO database. We first compared gene expression between cancerous tissues and normal tissues for each type of cancer and then identified changes that were common to a variety of cancer types.

Results

Our analysis found that significant downregulation of MAO-A, the enzyme that metabolizes serotonin, occurred in multiple tissues from humans, rodents, and fish. MAO-A expression was decreased in 95.4% of human cancer patients and 94.2% of animal cancer cases compared to the non-cancerous controls.

Conclusion

These are the first findings that identify a single reliable change in so many different cancers. Future studies should investigate links between MAO-A suppression and the development of cancer to determine the extent that MAO-A suppression contributes to increased cancer risk.