Quantitative RT-PCR analysis of estrogen receptor gene expression in laser microdissected prostate cancer tissue.
BACKGROUND
Real-time quantitative RT-PCR analysis of laser microdissected tissue is considered the most accurate technique for determining tissue gene expression. The discovery of estrogen receptor beta (ERbeta) has focussed renewed interest on the role of estrogen receptors in prostate cancer, yet few studies have utilized the technique to analyze estrogen receptor gene expression in prostate cancer.


METHODS
Fresh tissue was obtained from 11 radical prostatectomy specimens and from 6 patients with benign prostate hyperplasia. Pure populations of benign and malignant prostate epithelium were laser microdissected, followed by RNA isolation and electrophoresis. Quantitative RT-PCR was performed using primers for androgen receptor (AR), estrogen receptor beta (ERbeta), estrogen receptor alpha (ERalpha), progesterone receptor (PGR) and prostate specific antigen (PSA), with normalization to two housekeeping genes. Differences in gene expression were analyzed using the Mann-Whitney U-test. Correlation coefficients were analyzed using Spearman's test.


RESULTS
Significant positive correlations were seen when AR and AR-dependent PSA, and ERalpha and ERalpha-dependent PGR were compared, indicating a representative population of RNA transcripts. ERbeta gene expression was significantly over-expressed in the cancer group compared with benign controls (P < 0.01). In contrast, PGR expression was significantly down-regulated in the cancer group (P < 0.05). There were no significant differences in AR, ERalpha or PSA expression between the groups. This study represents the first to show an upregulation of ERbeta gene expression in laser microdissected prostate cancer specimens.


CONCLUSIONS
In concert with recent studies the findings suggest differential production of ERbeta splice variants, which may play important roles in the genesis of prostate cancer.
Walton
Thomas J
TJ
The John van Geest Cancer Research Centre, School of Biomedical and Natural Sciences, Nottingham Trent University, Clifton Campus, Clifton Lane, Nottingham, United Kingdom. tjwalton1974@btinternet.com
Li
Geng
G
McCulloch
Thomas A
TA
Seth
Rashmi
R
Powe
Desmond G
DG
Bishop
Michael C
MC
Rees
Robert C
RC
D017931:DNA Primers; D004273:DNA, Neoplasm / Q000235:genetics; D047628:Estrogen Receptor alpha / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007834:Lasers; D008297:Male; D042282:Microdissection; D016133:Polymerase Chain Reaction; D011467:Prostate / Q000502:physiology; D017430:Prostate-Specific Antigen / Q000235:genetics; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology* / Q000601:surgery; D012334:RNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D011944:Receptors, Androgen / Q000235:genetics; D011960:Receptors, Estrogen / Q000235:genetics*; D011980:Receptors, Progesterone / Q000235:genetics; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
D017931:DNA Primers; D004273:DNA, Neoplasm; D047628:Estrogen Receptor alpha; D012334:RNA, Neoplasm; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D017430:Prostate-Specific Antigen