The expression of thyroid hormone receptor isoforms in human astrocytomas

BackgroundThyroid hormone plays a major role in normal mammalian brain maturation and affects the development of astrocytes. The expression of TR isoforms has been studied in different neoplasias. Increasing evidence has suggested that aberrant expression of TR isoforms could be associated with tumorigenesis. However, little was studied about the expression of TR isoforms in human astrocytomas.MethodsIn this study, RT-PCR was used to examine the expression of human TR isoforms in 34 human astrocytoma samples.ResultsWe compared the TR expression between low grade (WHO grade II) and high grade (WHO grade III and IV). The frequency of TRα1 or TRα2 expression significantly decreased with the grade of malignancy (P = .005 and P = .043, respectively). However, the frequency of TRβ1 expression significantly increased with the grades of malignancy astrocytomas (P = .017).ConclusionsOur study demonstrated for the first time that TR isoforms are indeed expressed in human astrocytomas. The expression of TR isoforms is correlated to the malignancy grading of astrocytomas. Our result provides insight into the potential use of hormonal therapy for brain tumors that overexpress or underexpress TRs.