Detection of mRNA levels for the estrogen alpha, estrogen beta and androgen nuclear receptor genes in archival breast cancer tissue.
Previous studies in our laboratory have shown association of nuclear receptor expression and histological breast cancer grade. To further investigate these findings, it was the objective of this study to determine if expression levels of the estrogen alpha, estrogen beta and androgen nuclear receptor genes varied in different breast cancer grades. RNA extracted from paraffin embedded archival breast tumour tissue was converted into cDNA and cDNA underwent PCR to enable quantitation of mRNA expression. Expression data was normalised against the 18S ribosomal gene multiplex and analysed using ANOVA. Analysis indicated a significant alteration of expression for the androgen receptor in different cancer grades (P=0.014), as well as in tissues that no longer possess estrogen receptor alpha proteins (P=0.025). However, expression of estrogen receptors alpha and beta did not vary significantly with cancer grade (P=0.057 and 0.622, respectively). Also, the expression of estrogen receptor alpha or beta did not change, regardless of the presence of estrogen receptor alpha protein in the tissue (P=0.794 and 0.716, respectively). Post-hoc tests indicate that the expression of the androgen receptor is increased in estrogen receptor negative tissue as well as in grade 2 and grade 3 tumours, compared to control tissue. This increased expression in late stage breast tumours may have implications to the treatment of breast tumours, particularly those lacking expression of other nuclear receptor genes.
Smith
Robert A
RA
Genomics Research Centre and Wesley Research Institute, School of Health Science, Griffith University Gold Coast, PMB 50 Gold Coast Mail Centre, Qld. 9726, Australia.
Lea
Rod A
RA
Weinstein
Stephen R
SR
Griffiths
Lyn R
LR
D001943:Breast Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D017931:DNA Primers / Q000737:chemistry; D047628:Estrogen Receptor alpha / Q000096:biosynthesis*; D047629:Estrogen Receptor beta / Q000096:biosynthesis*; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D012333:RNA, Messenger / Q000378:metabolism*; D011944:Receptors, Androgen / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
C410798:AR protein, human; D017931:DNA Primers; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D012333:RNA, Messenger; D011944:Receptors, Androgen