title: The expression of thyroid hormone receptor isoforms in human astrocytomas.
abstract: 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.
authors.affiliation: Division of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
authors.forename: Shiuh-Lin
authors.initials: SL
authors.lastname: Hwang
authors.forename: Chih-Lung
authors.initials: CL
authors.lastname: Lin
authors.forename: Ann-Shung
authors.initials: AS
authors.lastname: Lieu
authors.forename: Yan-Fen
authors.initials: YF
authors.lastname: Hwang
authors.forename: Shen-Long
authors.initials: SL
authors.lastname: Howng
authors.forename: Yi-Ren
authors.initials: YR
authors.lastname: Hong
authors.forename: Dyi-Sheng
authors.initials: DS
authors.lastname: Chang
authors.forename: Kung-Shing
authors.initials: KS
authors.lastname: Lee
mesh_terms: 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
chemical_list: D011988:Receptors, Thyroid Hormone; D037021:Thyroid Hormone Receptors alpha; D037042:Thyroid Hormone Receptors beta; D012313:RNA