Serum metabolomics in oral leukoplakia and oral squamous cell carcinoma

Metabolomics is a core discipline of system biology focusing on the study of low molecular weight compounds in biological system. Analysis of human metabolome, which is composed of diverse group of metabolites, can aid in diagnosis and prognosis of oral squamous cell carcinoma (OSCC).

The aim of the present study is to analyze and identify serum metabolites in oral leukoplakia and OSCC as a potential diagnostic biomarker and a predictor for malignant transformation of oral leukoplakia.

Serum metabolomic profile of patients diagnosed with oral leukoplakia (n = 21) and OSCC (n = 22) was compared with normal controls (n = 18) using quadrupole time of flight-liquid chromatography-mass spectrometry. MassHunter profile software was used for metabolite identification, and statistical analysis to assess the variation of the metabolites was performed using Mass Profiler Professional software. Statistical significance between the three groups was expressed using ANOVA (P < 0.05), and intergroup comparison was done using Student's t-test (P < 0.05).

Significant upregulation of estradiol-17-beta-3-sulfate, L-carnitine, 5-methylthioadenosine (MTA), 8-hydroxyadenine, 2-methylcitric acid, putrescine, and estrone-3-sulfate was seen in oral leukoplakia and OSCC than in normal controls. Furthermore, significant upregulation of 5,6-dihydrouridine, 4-hydroxypenbutolol glucuronide, 8-hydroxyadenine, and putrescine was evident in OSCC group than in oral leukoplakia.

Upregulation of L-carnitine, lysine, 2-methylcitric acid, putrescine; 8-hydroxyadenine; 17-estradiol; 5,6-dihydrouridine; and MTA suggests their diagnostic potential in oral leukoplakia and OSCC. Further, a significant upregulation of putrescine, 8-hydroxyadenine, and 5,6-dihydrouridine in OSCC than in oral leukoplakia indicates their potential role in predicting the malignant transformation of oral leukoplakia.