The expression of thyroid hormone receptor isoforms in human astrocytomas.
BACKGROUND
Thyroid 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.


METHODS
In this study, RT-PCR was used to examine the expression of human TR isoforms in 34 human astrocytoma samples.


RESULTS
We compared the TR expression between low grade (WHO grade II) and high grade (WHO grade III and IV). The frequency of TRalpha1 or TRalpha2 expression significantly decreased with the grade of malignancy (P=.005 and P=.043, respectively). However, the frequency of TRbeta1 expression significantly increased with the grades of malignancy astrocytomas (P=.017).


CONCLUSIONS
Our 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.
Hwang
Shiuh-Lin
SL
Division of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
Lin
Chih-Lung
CL
Lieu
Ann-Shung
AS
Hwang
Yan-Fen
YF
Howng
Shen-Long
SL
Hong
Yi-Ren
YR
Chang
Dyi-Sheng
DS
Lee
Kung-Shing
KS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism; D001254:Astrocytoma / Q000378:metabolism* / Q000473:pathology; D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D011988:Receptors, Thyroid Hormone / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012727:Sex Characteristics; D037021:Thyroid Hormone Receptors alpha / Q000096:biosynthesis / Q000235:genetics; D037042:Thyroid Hormone Receptors beta / Q000096:biosynthesis / Q000235:genetics
D011988:Receptors, Thyroid Hormone; D037021:Thyroid Hormone Receptors alpha; D037042:Thyroid Hormone Receptors beta; D012313:RNA