Alteration in Gene Pair Correlations in Tryptophan Metabolism as a Hallmark in Cancer Diagnosis

Meena Kishore Sakharkar; Sarinder Kaur Dhillon; Karthic Rajamanickam; Benjamin Heng; Nady Braidy; Gilles J Guillemin; Jian Yang

doi:10.1177/1178646920977013

Alteration in Gene Pair Correlations in Tryptophan Metabolism as a Hallmark in Cancer Diagnosis

Int J Tryptophan Res. 2020 Dec 10:13:1178646920977013. doi: 10.1177/1178646920977013. eCollection 2020.

Authors

Meena Kishore Sakharkar¹, Sarinder Kaur Dhillon², Karthic Rajamanickam¹, Benjamin Heng³, Nady Braidy^{3

4}, Gilles J Guillemin³, Jian Yang¹

Affiliations

¹ Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada.
² Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
³ Neuroinflammation Research Group, MND Research Centre, Department of Biological Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia.
⁴ Centre for Healthy Brain Ageing, School of Psychiatry, University of New South Wales, Faculty of Medicine, Sydney, NSW, Australia.

Abstract

Tryptophan metabolism plays essential roles in both immunomodulation and cancer development. Indoleamine 2,3-dioxygenase, a rate-limiting enzyme in the metabolic pathway, is overexpressed in different types of cancer. To get a better understanding of the involvement of tryptophan metabolism in cancer development, we evaluated the expression and pairwise correlation of 62 genes in the metabolic pathway across 12 types of cancer. Only gene AOX1, encoding aldehyde oxidase 1, was ubiquitously downregulated, Furthermore, we observed that the 62 genes were widely and strongly correlated in normal controls, however, the gene pair correlations were significantly lost in tumor patients for all 12 types of cancer. This implicated that gene pair correlation coefficients of the tryptophan metabolic pathway could be applied as a prognostic and/or diagnostic biomarker for cancer.

Keywords: TCGA; Tryptophan metabolism; cancers; differentially expressed gene; gene pair correlation.