Novel oncogene GAEC1: involved in pathogenesis and potential use in differential diagnoses of thyroid tumours

Abstract

GAEC1 is a novel oncogene located at 7q22.1. Thyroid tumours have various morphological types with different clinical behaviours. The aims of this study are to identify the roles of GAEC1 copy number change in thyroid tumours. The copy number of GAEC1 was studied in 104 different thyroid tumours (17 follicular adenomas, 31 minimally invasive follicular carcinomas, 12 widely invasive follicular carcinomas and 44 papillary thyroid carcinomas) and 23 nodular hyperplasia samples using real-time PCR. Significant differences in copy number change for the GAEC1 oncogene between non-tumour (nodular hyperplasia), benign and borderline thyroid tumours (follicular adenoma and minimally invasive follicular carcinoma) and thyroid cancers (papillary thyroid carcinoma and follicular carcinoma) were noted (<i>p</i><0.0001). In addition to significant change of copy number in follicular neoplasms, the majority of the follicular carcinoma (83%) revealed deletion of GAEC1. In papillary carcinoma, GAEC1 deletion was more often noted in advanced stage (stage 3) (<i>p</i>=0.04). To conclude, GAEC1 copy number changes were noted in different thyroid lesions. Deletion or amplification of GAEC1 was often noted in certain types of thyroid tumours. The findings imply that GAEC1 is important in the pathogenesis and may act as a molecular diagnostic maker in some thyroid tumours.