Apolipoprotein D (APOD) is a putative biomarker of androgen receptor function in androgen insensitivity syndrome

  • Mahesh Appari
  • Ralf Werner
  • Lutz Wünsch
  • Gunnar Cario
  • Janos Demeter
  • Olaf Hiort
  • Felix Riepe
  • James D. Brooks
  • Paul-Martin Holterhus
Original Article

Abstract

Androgen insensitivity syndrome (AIS) is the most common cause of disorders of sex development usually caused by mutations in the androgen receptor (AR) gene. AIS is characterized by a poor genotype–phenotype correlation, and many patients with clinically presumed AIS do not seem to have mutations in the AR gene. We therefore aimed at identifying a biomarker enabling the assessment of the cellular function of the AR as a transcriptional activator. In the first step, we used complementary DNA (cDNA) microarrays for a genome-wide screen for androgen-regulated genes in two normal male primary scrotal skin fibroblast strains compared to two labia majora fibroblast strains from 46,XY females with complete AIS (CAIS). Apolipoprotein D (APOD) and two further transcripts were significantly upregulated by dihydrotestosterone (DHT) in scrotum fibroblasts, while CAIS labia majora cells were unresponsive. Microarray data were well correlated with quantitative real-time polymerase chain reaction (qRT-PCR; R = 0.93). Subsequently, we used qRT-PCR in independent new cell cultures and confirmed the significant DHT-dependent upregulation of APOD in five normal scrotum strains [13.5 ± 8.2 (SD)-fold] compared with three CAIS strains (1.2 ± 0.7-fold, p = 0.028; t test) and six partial androgen insensitivity syndrome strains (2 ± 1.3-fold, p = 0.034; t test). Moreover, two different 17ß-hydroxysteroid dehydrogenase III deficiency labia majora strains showed APOD induction in the range of normal scrotum (9.96 ± 1.4-fold), supporting AR specificity. Therefore, qRT-PCR of APOD messenger RNA transcription in primary cultures of labioscrotal skin fibroblasts is a promising tool for assessing AR function, potentially allowing a function-based diagnostic evaluation of AIS in the future.

Keywords

Androgen insensitivity syndrome Disorders of sex development Apolipoprotein D Genital fibroblasts 

Abbreviations

APOD

Apolipoprotein D

AR

Androgen receptor

AIS

Androgen insensitivity syndrome

PAIS

Partial androgen insensitivity syndrome

CAIS

Complete androgen insensitivity syndrome

DHT

Dihydrotestosterone

AZA

5-Aza-deoxy-cytidine

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Mahesh Appari
    • 1
  • Ralf Werner
    • 3
  • Lutz Wünsch
    • 4
  • Gunnar Cario
    • 2
  • Janos Demeter
    • 5
  • Olaf Hiort
    • 3
  • Felix Riepe
    • 1
  • James D. Brooks
    • 6
  • Paul-Martin Holterhus
    • 1
  1. 1.Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, University-Hospital Schleswig-HolsteinChristian Albrechts University of KielKielGermany
  2. 2.Department of Pediatrics, University-Hospital Schleswig-HolsteinChristian Albrechts University of KielKielGermany
  3. 3.Department of Pediatric and Adolescent Medicine, University-Hospital Schleswig-HolsteinUniversity of LübeckLübeckGermany
  4. 4.Department of Pediatric SurgeryUniversity Hospital Schleswig-HolsteinLübeckGermany
  5. 5.Department of BiochemistryStanford University School of MedicineStanfordUSA
  6. 6.Department of UrologyStanford University School of MedicineStanfordUSA

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