| Androgen Receptor |  |
The intracellular action of androgens is mediated by the androgen receptor, which is a key element of the androgen signal transduction cascade and a target of endocrine therapy for prostatic carcinoma. Qualitative and quantitative alterations of androgen receptor expression in prostatic carcinomas and their possible implications for tumor progression and treatment are therefore of diagnostic and research interest. Findings in prostatic tumor cell lines of rat and human origin suggest that reduction of androgen receptor protein expression is accompanied by an increase in tumor aggressiveness. However, immunohistochemical analysis and binding assays have demonstrated the presence of androgen receptors in all histological types of prostatic carcinoma and in both therapy-responsive as well as therapy-unresponsive tumor.
Much of the immunohistochemical studies of androgen receptors have been related to prostatic carcinoma and experimental animals. The androgen receptor content of prostatic carcinoma has been inversely correlated to Gleason grade in stage D2 carcinomas, although it was unrelated to extent of disease and response to hormonal therapy at three months. Patients with 48% or more androgen receptor-positive cells had statistically significant better outcome in terms of both progression-free and cause-specific survival (Takeda et al, 1996). Another study suggested that pretreatment androgen receptor expression alone is not related to prognosis of hormonally treated prostate cancer; however, when combined with bcl-2 expression, it acts as an independent prognostic factor for clinical progression (Noordzij et al, 1997).
The variability of androgen receptor protein content per unit nuclear area has been shown to increase with increasing histological grade, suggesting that this variability might account for the response to endocrine therapy in high grade tumors (Magi-Galluzzi et al, 1997). The extent of heterogeneity of androgen receptor expression may be a useful indicator of response to hormonal therapy (Klocker et al, 1994).
Mouse Monoclonal, Clone: AR441| | 0.1 ml concentrated | 200M-14 | | | 0.5 ml concentrated | 200M-15 | | | 1 ml concentrated | 200M-16 | | | 1 ml prediluted | 200M-17 | | | 7 ml prediluted | 200M-18 | | | 5 Positive Control Slides | 200S | | |
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Regulatory Status
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