Androgen receptor involvement in the progression of prostate cancer.

Suzuki, Hiroyoshi; Ueda, Takeshi; Ichikawa, Tomohiko; Itô, Haruo

doi:10.1677/erc.0.0100209

Cited by 156 publications

(127 citation statements)

References 33 publications

(31 reference statements)

Supporting

Mentioning

116

Contrasting

Unclassified

Order By: Relevance

“…We used several cell lines in these studies: DU145, an invasive and metastatic androgen-independent human PCa cell line, either transfected with the wild-type (wt) human androgen receptor (hAR) or with a control neomycin-resistant plasmid DNA 18 ; LNCaP cells, which express mutant AR 19 that has been identified frequently in PCa patients who have AI disease 20 ; and CWR22R-2152 xenograft-derived cells. 21,22 Despite having mutant AR, CWR22R-2152 and LNCaP ARs have been shown to bind androgens and to maintain their ligand-dependent transactivational activity.…”

Section: Cell Lines and Xenograft-derived Cell Culturesmentioning

confidence: 99%

Retracted: Additive antitumor effects of the epidermal growth factor receptor tyrosine kinase inhibitor, gefitinib (Iressa), and the nonsteroidal antiandrogen, bicalutamide (Casodex), in prostate cancer cells in vitro

Festuccia

Gravina

Angelucci

et al. 2005

Intl Journal of Cancer

View full text Add to dashboard Cite

Progression from an androgen-dependent to an androgen-independent state often occurs in patients with prostate cancer (PCa) who undergo hormonal therapy. We have investigated whether inhibition of the epidermal growth factor receptor (EGFR) signaling pathway affects the antitumor effect of a nonsteroidal antiandrogen. Gefitinib (Iressa), an EGFR tyrosine kinase inhibitor, and bicalutamide (Casodex), a nonsteroidal antiandrogen [androgen receptor (AR) antagonist], were administered alone and in combination to AR-positive human PCa cell lines. FACS analysis showed lower EGFR expression levels on AR-positive cells (LNCaP, CWR22, CWR22R 2152 and AR-transfected DU145 cell lines) compared with AR-negative cells (DU145, PC3 and TSUPr1). Moreover, in AR-transfected DU145 cells, chronic treatment with bicalutamide increased EGFR expression to levels similar to androgen-independent DU145 cells. All AR-positive PCa cell lines were sensitive to gefitinib (IC 50 = 0.1-0.6 mM), whereas higher concentrations of bicalutamide were needed to reduce AR-positive PCa cell line proliferation (IC 50 = 0.8-2.0 mM). Low doses of gefitinib increased the antitumor effects of bicalutamide by strongly reducing the IC 50 of bicalutamide (approximately 10-fold). Similarly, bicalutamide increased the antiproliferative effects of gefitinib by reducing the IC 50 of gefitinib (approximately 5-fold). Taken together, our data suggest that in androgen-dependent cell lines, addition of gefitinib in combination with bicalutamide results in concurrent dual inhibition of AR and EGFR/HER2 pathways. This causes a significant delay in the onset of EGFRdriven androgen independence. ' 2005 Wiley-Liss, Inc. Key words: prostate cancer; hormonal therapy; EGFR; androgenindependent tumorsIn industrialized countries, prostate cancer (PCa) is the most frequently occurring malignancy in men, representing the second highest cause of cancer-related death. PCa usually begins as an androgen-sensitive, androgen-dependent (AD), nonmetastatic cancer, which without intervention may follow a gradual transition into a highly metastatic and then androgen-insensitive (AI) variety. The androgen receptor (AR) is a nuclear receptor that cooperates with multiple proteins to exert its biologic function. Upon binding to the ligand testosterone/5 -dihydrotestosterone (DHT), the AR can bind to the androgen response element (ARE) on the 5 0 promoter of target genes, resulting in the modulation of cell growth. Until relatively recent times, endocrine response pathways in PCa were described solely in terms of the intracellular pathways used by the androgens and the subsequent destructive effects exerted on AR signaling by antihormonal treatments. 1 It is widely accepted that androgens promote tumor growth by binding to ARs and acting as nuclear transcription factors that regulate the expression of genes involved in cell proliferation and survival mechanisms. In contrast, hormonal therapies promote tumor regression either by reducing the amount of androgens available to the tumor cells or...

show abstract

Section: Cell Lines and Xenograft-derived Cell Culturesmentioning

confidence: 99%

Retracted: Additive antitumor effects of the epidermal growth factor receptor tyrosine kinase inhibitor, gefitinib (Iressa), and the nonsteroidal antiandrogen, bicalutamide (Casodex), in prostate cancer cells in vitro

Festuccia

Gravina

Angelucci

et al. 2005

Intl Journal of Cancer

View full text Add to dashboard Cite

show abstract

“…55,56 The SRY (sex-determining region Y) gene has been found to interact with and negatively regulate AR transcriptional activity. Transient expression of SRY in LNCaP prostate cancer cells repressed expression of an androgen-dependent PSA reporter gene and stable SRY expression repressed the endogenous PSA gene.…”

Section: Discussionmentioning

confidence: 99%

Prostate cancer incidence varies among males from different Y-chromosome lineages

Ewis

Lee

Naroda

et al. 2006

Prostate Cancer Prostatic Dis

View full text Add to dashboard Cite

The incidence rate of prostate cancer in African-American males is two times higher than Caucasian men and ten times higher than Japanese men. The geographical specificity of Y haplogroups implies that males from different ethnic groups undoubtedly have various Y lineages with different Y-chromosomal characteristics that may affect their susceptibility or resistance to such a malespecific cancer. To confirm this hypothesis we studied the Y-chromosomal haplogroups of 92 Japanese prostate cancer patients comparing them with randomly selected 109 unrelated healthy Japanese male controls who were confirmed to be residents of the same geographical area. Males could be classified using three binary Y-chromosome markers (sex-determining region Y (SRY), YAP, 47z) into four haplogroups DE, O2b*, O2b1, and untagged group. Our results confirmed that prostate cancer incidence varies among males from different Y-chromosome lineages. Males from DE and the untagged haplogroups are at a significantly higher risk to develop prostate cancer than O2b* and O2b1 haplogroups (P ¼ 0.01), odds ratio 2.17 and 95% confidence interval (1.16-4.07). Males from haplogroup DE are over-represented in the patient group showing a percentage of 41.3%. The underlying possible causes of susceptibility variations of different Y lineages for such a male-specific cancer tumorigenesis are discussed. These findings explain the lower incidence of prostate cancer in Japanese and other South East Asian males than other populations. To our knowledge, this is the first reliable study examining the association between prostate cancer and Y-chromosomal haplogroups, comparing prostate cancer patients with carefully selected matched controls.

show abstract

“…However, development of resistance and heterogeneous responses to steroid treatments over prolonged therapy are not uncommon. 36,37 We reasoned that the ligand-independent cell survival effects of EcR and USP in the PG of Drosophila could eventually help to understand that heterogeneity of responses to therapies. In that context, we explored the effects of EcR and USP deprivation in yorkie-elicited PG tumors.…”

Section: After Tool Validation (Supplementary Data and Supplementarymentioning

confidence: 99%

Ligand-independent requirements of steroid receptors EcR and USP for cell survival

2015

View full text Add to dashboard Cite

The active form of the Drosophila steroid hormone ecdysone, 20-hydroxyecdysone (20E), binds the heterodimer EcR/USP nuclear receptor to regulate target genes that elicit proliferation, cell death and differentiation during insect development. Although the 20E effects are relatively well known, the physiological relevance of its receptors remains poorly understood. We show here that the prothoracic gland (PG), the major steroid-producing organ of insect larvae, requires EcR and USP to survive in a critical period previous to metamorphosis, and that this requirement is 20E-independent. The cell death induced by the downregulation of these receptors involves the activation of the JNK-encoding basket gene and it can be rescued by upregulating EcR isoforms which are unable to respond to 20E. Also, while PG cell death prevents ecdysone production, blocking hormone synthesis or secretion in normal PG does not lead to cell death, demonstrating further the ecdysone-independent nature of the receptor-deprivation cell death. In contrast to PG cells, wing disc or salivary glands cells do not require these receptors for survival, revealing their cell and developmental time specificity. Exploring the potential use of this feature of steroid receptors in cancer, we assayed tumor overgrowth induced by altered yorkie signaling. This overgrowth is suppressed by EcR downregulation in PG, but not in wing disc, cells. The mechanism of all these cell death features is based on the transcriptional regulation of reaper. These novel and context-dependent functional properties for EcR and USP receptors may help to understand the heterogeneous responses to steroid-based therapies in human pathologies. Steroid hormones control multiple biological processes and, consequently, their faulty regulation underlies many pathologies. 1,2 The main Drosophila steroid hormone, ecdysone, is synthesized in the larval prothoracic gland (PG) using dietary sterols and cytochrome P450 enzymes. 3 Following its pulsated secretion into the hemolymph, peripheral tissues convert ecdysone into biologically active 20-hydroxyecdysone (20E) to control larval molting and metamorphosis. 4 The 20E signal is transduced by heterodimers of two nuclear receptors, ecdysone receptor (EcR) and Ultraspiracle (USP). 5 USP exhibits a single form throughout development. By contrast, EcR encodes three protein isoforms (EcRA, EcRB1 and EcRB2). These show common DNA-and hormone-binding domains but different N-termini although all of them can heterodimerize USP. 6,7 Each EcR isoform is hypothesized to have specific functions based on their distinct spatial and temporal patterns and N-termini. [8][9][10] EcR and USP DNA-binding domains recognize ecdysone response sequences which are short palindromes. 11 Like its vertebrate counterparts, 12 the ligand-EcR/USP complex activates transcription, whereas the unliganded receptor act as a repressor. [13][14][15] The in vivo validation of repressor activities for unliganded complexes, however, is mostly indirect. For example, EcR or USP loss...

show abstract

Androgen receptor involvement in the progression of prostate cancer.

Cited by 156 publications

References 33 publications

Retracted: Additive antitumor effects of the epidermal growth factor receptor tyrosine kinase inhibitor, gefitinib (Iressa), and the nonsteroidal antiandrogen, bicalutamide (Casodex), in prostate cancer cells in vitro

Retracted: Additive antitumor effects of the epidermal growth factor receptor tyrosine kinase inhibitor, gefitinib (Iressa), and the nonsteroidal antiandrogen, bicalutamide (Casodex), in prostate cancer cells in vitro

Prostate cancer incidence varies among males from different Y-chromosome lineages

Ligand-independent requirements of steroid receptors EcR and USP for cell survival

Contact Info

Product

Resources

About