An AKT activity threshold regulates androgen-dependent and androgen-independent PSA expression in prostate cancer cell lines

2008 ◽  
Vol 389 (6) ◽  
Author(s):  
Miltiadis Paliouras ◽  
Eleftherios P. Diamandis
Keyword(s):  
Prostate Cancer ◽  
Cell Lines ◽  
Cancer Progression ◽  
Intracellular Signaling ◽  
Specific Antigen ◽  
Independent State ◽  
Epidermal Growth ◽  
Androgen Independent

AbstractThe androgen receptor (AR) plays an important role in early prostate cancer by activating transcription of a number of genes participating in cell proliferation and growth and cancer progression. However, as the cancer progresses, prostate cancer cells transform from an androgen-dependent to an androgen-independent state. Androgen-independent prostate cancer can manifest itself in several forms, including a percentage of cancers that show reduced levels of prostate-specific antigen (PSA) and can progress without the need for the ligand or active receptor. Therefore, our goal was to examine the role of intracellular signaling pathways in an androgen-independent prostate cancerin vitromodel. Using the cell line PC3(AR)2, we stimulated cells with 5-α-dihydrotestosterone (DHT) and epidermal growth factor (EGF) and then analyzed PSA expression. We observed lower PSA expression when cells were jointly stimulated with DHT and EGF, and this was associated with an increase in AKT activity. We examined the role of AKT in AR activity and PSA expression by creating stable PC3(AR)2cell lines transfected with a PI3K-Ras-effector loop mutant. These cell lines showed lower DHT-stimulated PSA expression that correlated to changes in the phosphorylated state of AR. Therefore, we propose anin vitroandrogen-independent model in which a PI3K/AKT activity threshold and subsequent AR transactivation regulate PSA expression.

scholarly journals Role of a novel race-related tumor suppressor microRNA located in frequently deleted chromosomal locus 8p21 in prostate cancer progression

2019 ◽  
Vol 40 (5) ◽  
pp. 633-642 ◽  
Author(s):  
Divya Bhagirath ◽  
Thao Ly Yang ◽  
Z Laura Tabatabai ◽  
Varahram Shahryari ◽  
Shahana Majid ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Tumor Suppressor ◽  
Cell Lines ◽  
Cancer Progression ◽  
Specific Antigen ◽  
Tumor Grade ◽  
Clinical Samples ◽  
Mesenchymal Transition ◽  
Microrna Genes

Abstract The prostate cancer (PCa) genome is characterized by deletions of chromosome 8p21–22 region that increase significantly with tumor grade and are associated with poor prognosis. We proposed and validated a novel, paradigm-shifting hypothesis that this region is associated with a set of microRNA genes—miR-3622, miR-3622b, miR-383—that are lost in PCa and play important mechanistic roles in PCa progression and metastasis. Extending our hypothesis, in this study, we evaluated the role of a microRNA gene located in chromosome 8p—miR-4288—by employing clinical samples and cell lines. Our data suggests that (i) miR-4288 is widely downregulated in primary prostate tumors and cell lines; (ii) miR-4288 expression is lost in metastatic castration-resistant PCa; (ii) miR-4288 downregulation is race-related PCa alteration that is prevalent in Caucasian patients and not in African Americans; (iii) in Caucasians, miR-4288 was found to be associated with increasing tumor grade and high serum prostate-specific antigen, suggesting that miR-4288 downregulation/loss may be associated with tumor progression specifically in Caucasians; (iv) miR-4288 possess significant potential as a molecular biomarker to predict aggressiveness/metastasis; and (v) miR-4288 is anti-proliferative, is anti-invasive and inhibits epithelial-to-mesenchymal transition; and (vi) miR-4288 directly represses expression of metastasis/invasion-associated genes MMP16 and ROCK1. Thus, the present study demonstrates a tumor suppressor role for a novel miRNA located with a frequently lost region in PCa, strengthening our hypothesis that this locus is causally related to PCa disease progression via loss of microRNA genes. Our study suggests that miR-4288 may be a novel biomarker and therapeutic target, particularly in Caucasians.

scholarly journals Altered endocytosis of epidermal growth factor receptor in androgen receptor positive prostate cancer cell lines

2007 ◽  
Vol 38 (1) ◽  
pp. 51-66 ◽  
Author(s):  
Lorella Bonaccorsi ◽  
Daniele Nosi ◽  
Monica Muratori ◽  
Lucia Formigli ◽  
Gianni Forti ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Epidermal Growth Factor Receptor ◽  
Androgen Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cell Lines ◽  
Growth Factor Receptor ◽  
Epidermal Growth

Although androgens and the androgen receptor (AR) are involved in tumorigenesis of prostate cancer (PC) in initial phases, less clear is the role played in advanced androgen-independent (AI) stages of the disease. Several recent reports indicated that re-expression of AR in PC-derived cell lines determines a less aggressive phenotype of the cells. We have previously demonstrated that re-expression of AR decreases the invasion ability of PC3 cells in vitro by affecting signalling and internalization processes of epidermal growth factor receptor (EGFR). Here, we show that reduced EGFR internalization is also a characteristic of AR positive PC cell lines LNCaP and 22Rv1. Reduced internalization in PC3-AR cells is associated to a defective interaction between the EGFR and two adaptor proteins which mediate the endocytotic process, Grb2 and c-Cbl. As a consequence of such reduced interaction, ubiquitination of the receptor, which is mainly mediated by c-Cbl, is also altered. In addition, we show that internalized EGFR co-localizes with early endosome antigen-1, a marker of clathrin-mediated endocytosis, in PC3-Neo cells but not in AR positive cell lines. Conversely, EGFR maintains co-localization with caveolin-1 after EGF stimulation in PC3-AR cells. These data suggest that expression of AR affects clathrin-mediated endocytosis pathway of EGFR, which, according to recent findings, plays an essential role in the completeness of signalling of the receptor. Taken together, these data emphasize the role of AR in the regulation of EGFR endocytotic trafficking and active signalling in PC cells. In view of the role of EGFR signalling in invasion of carcinoma cells, our data may explain the lower invasive phenotype observed in AR-positive cell lines.

scholarly journals In vitro engineering of a bone metastases model allows for study of the effects of antiandrogen therapies in advanced prostate cancer

2021 ◽  
Vol 7 (27) ◽  
pp. eabg2564
Author(s):  
Nathalie Bock ◽  
Thomas Kryza ◽  
Ali Shokoohmand ◽  
Joan Röhl ◽  
Akhilandeshwari Ravichandran ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Progression ◽  
Advanced Prostate Cancer ◽  
Adaptive Responses ◽  
Metastatic Tissue ◽  
Metastatic Lesions ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

While androgen-targeted therapies are routinely used in advanced prostate cancer (PCa), their effect is poorly understood in treating bone metastatic lesions and ultimately results in the development of metastatic castrate resistant prostate cancer (mCRPC). Here, we used an all-human microtissue-engineered model of mineralized metastatic tissue combining human osteoprogenitor cells, 3D printing and prostate cancer cells, to assess the effects of the antiandrogens, bicalutamide, and enzalutamide in this microenvironment. We demonstrate that cancer/bone stroma interactions and antiandrogens drive cancer progression in a mineralized microenvironment. Probing the bone microenvironment with enzalutamide led to stronger cancer cell adaptive responses and osteomimicry than bicalutamide. Enzalutamide presented with better treatment response, in line with enzalutamide delaying time to bone-related events and enzalutamide extending survival in mCRPC. The all-human microtissue-engineered model of mineralized metastatic tissue presented here represents a substantial advance to dissect the role of the bone tumor microenvironment and responses to therapies for mCPRC.

scholarly journals Inhibition of LOXL2 Enhances the Radiosensitivity of Castration-Resistant Prostate Cancer Cells Associated with the Reversal of the EMT Process

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Peng Xie ◽  
Hongliang Yu ◽  
Feijiang Wang ◽  
Feng Yan ◽  
Xia He
Keyword(s):  
Prostate Cancer ◽  
Cell Apoptosis ◽  
Castration Resistant Prostate Cancer ◽  
Prostate Cancer Cells ◽  
Castration Resistant ◽  
Du145 Cells ◽  
Androgen Independent

Introduction. Radiotherapy is the mainstay in the treatment of prostate cancer. However, significant radioresistance of castration-resistant prostate cancer (CRPC) cells constitutes a main obstacle in the treatment of this disease. By using bioinformatic data mining methods, LOXL2 was found to be upregulated in both androgen-independent prostate cancer cell lines and radioresistant tumor samples collected from patients with prostate cancer. We speculate that LOXL2 may play an important role in the radioresistance of CRPC cells. Methods. The effect of LOXL2 knockdown on the radiosensitivity of androgen-independent prostate cancer cells lines was measured by the clonogenic assay and xenograft tumor experiments under in vitro and in vivo conditions, respectively. In studies on the mechanism, we focused on the EMT phenotype changes and cell apoptosis changes induced by LOXL2 knockdown in DU145 cells. The protein levels of three EMT biomarkers, namely, E-cadherin, vimentin, and N-cadherin, were measured by western blotting and immunohistochemical staining. Cell apoptosis after irradiation was measured by flow cytometry and caspase-3 activity assay. Salvage experiment was also conducted to confirm the possible role of EMT in the radiosensitization effect of LOXL2 knockdown in CRPC cells. Results. LOXL2 knockdown in CRPC cells enhanced cellular radiosensitivity under both in vitro and in vivo conditions. A significant reversal of EMT was observed in LOXL2-silenced DU145 cells. Cell apoptosis after irradiation was significantly enhanced by LOXL2 knockdown in DU145 cells. Results from the salvage experiment confirmed the key role of EMT process reversal in the radiosensitization effect of LOXL2 knockdown in DU145 cells. Conclusions. LOXL2 plays an important role in the development of cellular radioresistance in CRPC cells. Targeting LOXL2 may be a rational avenue to overcome radioresistance in CRPC cells. A LOXL2-targeting strategy for CRPC treatment warrants detailed investigation in the future.

In vitro efficacy of MAGMAS inhibition in prostate cancer.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 281-281
Author(s):  
Benjamin C. Powers ◽  
Bhaskar Das ◽  
Boumediene Bouzahzah ◽  
Peter J. Van Veldhuizen ◽  
Emma Borrego-Diaz Reyes
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Cell Lines ◽  
Cancer Cell ◽  
Prostate Cancer Cell ◽  
Cancer Cell Lines ◽  
Prostate Cancer Cell Lines ◽  
Gm Csf ◽  
Androgen Independent

281 Background: Prostate cancer is the second most common cancer worldwide in males. The initial treatment in advanced cases is medical or surgical castration. The outlook declines when prostate cancer advances independently, despite the aforementioned castration. Within the last ten years, a handful of new agents have proven effective in this castration-resistant phase, but finding more effective, novel ways of treating advanced prostate cancer is warranted. MAGMAS (mitochondria-associated, granulocyte-macrophage colony stimulating factor (GM-CSF) signaling molecule) is a protein ubiquitously expressed in eukaryotic cells that plays a key role in embryonal development in a variety of species. Overexpression of MAGMAS has anti-apoptotic effects, as GM-CSF is a growth factor essential for survival, proliferation and differentiation of cells. MAGMAS and GM-CSF receptor levels have been shown to be overexpressed in prostate cancer, but do not correlate with pathological grade or clinical stage. The purpose of our study was to evaluate the efficacy of a MAGMAS inhibitor, synthesized by Dr Bhaskar Das, in androgen-dependent and androgen-independent prostate cancer cell lines, as well as in a normal prostate cell line as another control. Methods: The different cell lines were treated with MAGMAS inhibitor at various concentrations in vitro. For analysis, we used MTT Cell Proliferation assay at 24 and 48 hours, per manufacturer’s protocol. We tested MAGMAS inhibitor effect on apoptosis/necrosis, cell migration and microtubule destabilization as well. Results: After prostate cancer cell lines were treated with MAGMAS inhibitor in vitro, cell proliferation and migration decreased, apoptosis and necrosis were induced, and microtubules were destabilized, all showing more impressive results in the androgen-independent cells. MAGMAS inhibition did not affect cell proliferation in the normal prostate cells. Conclusions: In vitro studies show MAGMAS inhibition proves efficacious in both androgen-dependent and androgen-independent prostate cancer cell lines. This will be evaluated further in a xenograft mouse model.

scholarly journals Extracellular Vesicles in Prostate Cancer: New Future Clinical Strategies?

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Ilaria Giusti ◽  
Vincenza Dolo
Keyword(s):  
Prostate Cancer ◽  
Extracellular Vesicles ◽  
Specific Antigen ◽  
Specific Marker ◽  
Cellular Origin ◽  
Organ Specific ◽  
Potential Use

Prostate cancer (PCa) is the most common cancer—excluding skin tumors—in men older than 50 years of age. Over time, the ability to diagnose PCa has improved considerably, mainly due to the introduction of prostate-specific antigen (PSA) in the clinical routine. However, it is important to take into account that although PSA is a highly organ-specific marker, it is not cancer-specific. This shortcoming suggests the need to find new and more specific molecular markers. Several emerging PCa biomarkers have been evaluated or are being assessed for their potential use. There is increasing interest in the prospective use of extracellular vesicles as specific markers; it is well known that the content of vesicles is dependent on their cellular origin and is strongly related to the stimulus that triggers the release of the vesicles. Consequently, the identification of a disease-specific molecule (protein, lipid or RNA) associated with vesicles could facilitate their use as novel biological markers. The present review describes severalin vitrostudies that demonstrate the role of vesicles in PCa progression and severalin vivostudies that highlight the potential use of vesicles as PCa biomarkers.

The relationship of HIF2 and the progression of PTEN-deficient mouse prostate tumors.

2011 ◽  
Vol 29 (7_suppl) ◽  
pp. 30-30
Author(s):  
W. Y. Kim ◽  
B. Zhou ◽  
G. Thomas
Keyword(s):  
Prostate Cancer ◽  
Cancer Cell ◽  
Cancer Progression ◽  
Prostate Cancer Cell ◽  
Deficient Mouse ◽  
Prostate Cancer Progression ◽  
Prostate Tumors ◽  
Mesenchymal Transition

30 Background: The hypoxia-inducible factor (HIF) transcription factor has already cemented its oncogenic role in the development of renal cell carcinoma (RCC). However, its role in the tumorigenesis of other solid tumors remains unspecificed. Our studies focus on a novel link between HIF and prostate carcinogenesis. Methods: Using both in vitro cell culture studies as well as in vivo studies (orthotopic xenograft and genetically engineered mouse models) we investigate the role of HIF in prostate cancer cell proliferation, invasion, and progression. Results: Both HIF1 and HIF2 appear to be necessary for the proliferation and invasion of prostate cancer cell lines in vitro. Preliminary analysis of a PTEN deficient mouse model of prostate cancer suggests that expression of a stabilized form of HIF2 promotes the development of a larger prostate tumor burden and a more aggressive histology (high grade prostate intraepithelial neoplasia [PIN] at earlier stages). Moreover, PTEN-deficient prostate tumors producing HIF2 are more proliferative and vascular and express increased levels of genes associated with epithelial to mesenchymal transition (EMT). Conclusions: There has been much interest in the role of angiogenesis and hypoxia in prostate cancer progression. Our preliminary data suggest that HIF2 is able to promote PTEN-deficient prostate cancer progression in mice by increasing proliferation, angiogenesis, and EMT. No significant financial relationships to disclose.

Prostate cancer inhibitory activity of a novel dual inhibitor, EL102, in combination with docetaxel, and its effects on MDR1-mediated drug resistance in vitro.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e15126-e15126
Author(s):  
Sharon A. Glynn ◽  
Aidan Toner ◽  
Joe Lewis ◽  
Frank Sullivan ◽  
Laura Breen ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Drug Resistance ◽  
Mouse Models ◽  
Cell Lines ◽  
Cancer Cell ◽  
Prostate Cancer Cell ◽  
Drug Resistant ◽  
Prostate Cancer Cell Lines ◽  
Androgen Independent

e15126 Background: EL102 is a dual-action drug promoting apoptosis and inhibiting angiogenesis. It exerts its action though the inhibition of Hif1a induced hypoxic signalling and induction of the Caspase 3/7 apoptotic cascade. The drug has equal activity in normoxia and hypoxia indicating it may be equally active in these different tumor compartments. We tested its ability to circumvent chemotherapeutic drug resistance. Methods: We assessed the ability of EL102 to inhibit prostate cancer cell proliferation and motility in vitro, calculating IC50s for CWR22, 22Rv2, PC3 and DU145 prostate cancer cell lines, comparing sensitivity between androgen dependent, androgen independent and metastatic prostate cancer. Additionally we assessed the activity of EL102 in combination with docetaxel in vitro and in murine CWR22 xenografts. The ability to overcome MDR1 and BCRP mediated drug resistance was also tested using DLKP drug resistant variants which exhibit 200 fold resistance to doxorubicin, docetaxel, paclitaxel and vincristine. Results: We found that prostate cancer cell lines are sensitive to EL102 with IC50s in the region of 10-50nM. Of particular interest was the identical sensitivity of the androgen independent 22Rv1 and its androgen dependent parent CWR22, suggesting ability to overcome hormone refractory prostate cancer. Additionally we demonstrate dose response for inhibition of cell motility in metastatic DU145. In CWR22 murine mouse models treatment with EL102 resulted in decreased tumor volume compared to control. A docetaxel and EL102 combination arm demonstrated the greater inhibition of tumor growth than EL102 or docetaxel alone. The lung cancer cell line DLKP, its drug resistant variants DLKPA (MDR1 overexpressing) and DLKPMitox (BCRP overexpressing) were equally sensitive to EL102 indicating that EL102 is not a substrate for MDR1 or BCRP. Conclusions: EL102 is a potential therapeutic for the treatment of prostate cancer, in particular in combination with docetaxel, and exhbibits the potential to overcome drug resistane. Future studies will include the efficacy of this drug in prostate cancer metastatic mouse models.

Sign in / Sign up

Export Citation Format

Share Document