High-resolution proteomics and metabolomics in thyroid cancer: Deciphering novel biomarkers

Abstract

Thyroid cancer (TC) is the most common endocrine malignancy and its incidence has been increasing sharply since the mid-1990s, being the fastest-increasing cancers in both men and women. Increased medical surveillance, the effect of environmental factors and more sensitive diagnostic tests, such as ultrasound and confirmation via fine-needle aspiration biopsy, are thought to account for this increased incidence. There are several histological types of thyroid cancer, including papillary thyroid carcinoma, follicular thyroid carcinoma, medullary thyroid carcinoma, and anaplastic thyroid carcinoma. Determining the type of thyroid cancer is crucial for the assessment of prognosis and treatment selection. Unfortunately, approximately 20–30% of patients undergoing fine-needle aspiration biopsy have inconclusive or indeterminate results, leading to unnecessary surgical intervention in 80% of patients with benign nodules. To resolve this diagnosis dilemma, new biomarkers of thyroid cancer are needed. Proteomic approaches offer an unbiased platform for the comprehensive analysis of the whole proteome in a certain physiological time. Although mRNA expression is widely considered to be indicative of protein expression, protein levels are the result of protein synthesis and degradation, and RNA levels are not informative of protein degradation. Clinically, there is increasing evidence for the role of proteomic and metabolomic technologies in biomarker discovery, providing novel information on the molecular events associated with TC, and potentially lead to the identification of novel drug targets. In this review, we will thoroughly describe the importance of novel proteomic and metabolomic approaches to identify new biomarkers associated with TC.