Hypoxia-inducible factor 1α: A screening tool for predicting development of castrate resistant prostate cancer.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e15117-e15117
Author(s):  
Weranja Kalana Bodhisiri Ranasinghe ◽  
Lin Xiao ◽  
Suzana Kovac ◽  
Mike Chang ◽  
Arthur Shulkes ◽  
...  

e15117 Background: Currently there is no method to determine which patients starting androgen deprivation therapy (ADT) for prostate cancer (PC) will progress to castrate resistant prostate cancer (CRPC) while the reasons for early metastases and chemoresistance in CRPCs are unknown. We aimed to investigate the potential role of hypoxia inducible factor 1α (HIF1α), a key transcription factor in the cell mediated adaptive response to changes in tissue oxygenation, in predicting the development of CRPC. Methods: 100 prostate tumour samples were divided into Gleason ≤7 (38) and Gleason >7 (62) and stained for HIF1α using immunohistochemistry, blinded to the outcomes. The outcomes of CRPC, metastases and PC specific death were measured and correlated with HIF1α expression. In vitro, the effects of HIF1α on proliferation, survival and migration of PC cells were assessed by cell count and Boyden chamber assays. Results: HIF1α expression in PC was independent of Gleason grade and tumour stage. HIF1α was an independent risk factor for development of CRPC (Hazard Ratio (HR) 10.4), progression to metastases (HR 9.8) and PC specific death (HR 13.4) at median times of 23, 24 and 25 months respectively, from the start of ADT on a multivariate Cox regression analysis (all p<0.05) adjusted for Gleason score, PSA and age. CRPC free survival, metastases free survival and PC specific survival were all significantly decreased in patients with HIF1α on Kaplan Meier analyses. The presence of HIF1α was highly sensitive (all 100%) with excellent negative predictive values (all 100%) for all 3 outcomes, but had poor specificity. HIF1α over-expressing PC3 cells (CRPC) were compared with androgen sensitive LNCaP cells in vitro. PC3 cells were resistant to cytotoxic agents including H2O2 (oxidative stress) and 5-fluorouracil (chemotherapy agent) and had higher rates of migration compared to LNCaP cells. HIF1α knockdown in PC3 cells reversed these effects. Protein translation efficiency in PC3 cells was significantly higher than LNCaP cells. Conclusions: HIF1α is a good screening tool for CRPC. HIF1α expression is likely to contribute to metastases and chemoresistance of CRPCs and is likely upregulated at protein translation in PC cells.

2021 ◽  
Vol 7 (27) ◽  
pp. eabg2564
Author(s):  
Nathalie Bock ◽  
Thomas Kryza ◽  
Ali Shokoohmand ◽  
Joan Röhl ◽  
Akhilandeshwari Ravichandran ◽  
...  

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.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 5057-5057
Author(s):  
Susan Halabi ◽  
Akash Roy ◽  
Qian Yang ◽  
Wanling Xie ◽  
William Kevin Kelly ◽  
...  

5057 Background: Radiographic progression-free survival (rPFS) is commonly used as a co-primary endpoint in randomized clinical trials in men with metastatic castrate-resistant prostate cancer (mCRPC). However, rPFS has not been established as a valid surrogate endpoint of overall survival (OS) in men with mCRPC. Here, we hypothesized that rPFS is a reliable surrogate for OS in mCRPC. We also explored whether PFS is a valid surrogate endpoint of OS at the aggregate trial level. Methods: We performed a systematic search of the literature encompassing the period January 2004-December 2020 using PubMed and clinical trials.gov to identify completed phase III trials in mCRPC post-docetaxel. Eligible trials had to be randomized phase III therapeutic trials that reported OS, PFS or rPFS. OS was measured from the date of random assignment to date of death from any cause or date of last follow-up. rPFS was defined as the time from random assignment to date of disease progression on CT and/or Tc bone scan per trial definition or death from any cause, whichever occurred first. PFS included PSA progression as a component of the composite endpoint. Trial level surrogacy was evaluated by fitting linear regression on the treatment effect of rPFS (or PFS) and OS (in other words, the weighted linear regression of the log(hazard ratio) of OS on the log(hazard ratio) of rPFS). It was pre-specified that rPFS would be considered a valid surrogate for OS if R² was 0·7 or higher. Results: We identified 33 in men with mCRPC post docetaxel approval. We assessed the association between PFS and OS in 29,456 patients from 30 trials. Overall, a moderate correlation was observed at the trial level between OS and PFS ( R2 = 0.46, 95 %CI = 0.20-0.68) in these trials. In 18 trials with 16,818 mCRPC patients where rPFS was considered as a key endpoint, a moderate correlation between the treatment effects on rPFS and OS was observed at the trial level ( R2= 0.65, 95% CI = 0.23-0.87). Conclusions: This meta-analysis demonstrates moderate correlation between treatment effects of rPFS and OS in patients with mCRPC. However, rPFS did not meet the pre-specified surrogacy threshold of 0.7. Clinical trial information: several.


2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 96-96
Author(s):  
Renee de Leeuw ◽  
Clay de Comstock ◽  
Daniela de Pollutri ◽  
Matthew Joseph Schiewer ◽  
Stephen J Ciment ◽  
...  

96 Background: Loss of retinoblastoma (RB) tumor suppressor is overrepresented in castrate-resistant prostate cancer (CRPC) compared to primary PCa. We previously showed using analyses of human tissue and in vitro and in vivo modeling that RB constrains androgen receptor (AR) function, and that loss of RB is sufficient promote resistance to castration and AR antagonists. Thus, novel strategies are needed to treat RB-deficient tumor. By contrast, in tumors retaining RB, suppressing enhancing RB activity would be of therapeutic advantage, and may be accomplished through next-generation Cdk4/6 inhibitors. Methods: Stable isogenic pairs of prostate cancer cell lines either retaining RB or RB depleted (by shRNA) were assessed in vitro and in xenografts for response to Cdk4/6 kinase inhibitors or the cabazitaxel. In addition, using an ex vivo explant assay, fresh tumor tissue samples from radical prostatectomy were exposed to the Cdk4/6 inhibitor or cabazitaxel for up to 7 days, and evaluated by IHC for Ki67, Caspase-3, and AR. Results: Cdk4/6 inhibition blocks tumor cell proliferation dependent on RB status. This was further confirmed ex vivo, as evidenced by a marked reduction in Ki67 staining in Cdk4/6 inhibitor treated explant tissue from two prostate cancer patients. Conversely, in vitro studies revealed a modest sensitization of RB-depleted tumors to cabazitaxel that was dramatically enhanced in vivo and after castration. Cabazitaxel, like docetaxel, targets the cell architecture and induces cell death, but also induces a distinct gene expression profile that may partially explain efficacy in docetaxel-resistant tumors. Neither taxane showed affects on AR nuclear localization using in vivoor explant studies. Conclusions: These results strongly support our hypothesis that RB status can be used as a metric to define therapeutic response to cabazitaxel, as such that loss of RB function induces sensitization taxanes, whereas RB proficient tumors give an enhanced response to Cdk4/6 kinase inhibitors.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e17541-e17541
Author(s):  
Mallika Marar ◽  
Ronac Mamtani ◽  
Vivek Narayan ◽  
Neha Vapiwala ◽  
Ravi Bharat Parikh

e17541 Background: Prospective evidence suggests that abiraterone use is associated with improved progression-free survival in African-American (AA) men with metastatic castrate-resistant prostate cancer (mCRPC) compared to white men. It is unclear whether race-based differences in treatment utilization and effectiveness exist for men with newly diagnosed mCRPC treated in real-world clinical practice. Methods: In this retrospective cohort study, we used the Flatiron Health electronic health record-derived de-identified database to identify patients with mCRPC who received first-line (1L) systemic therapy between 2012 and 2018. We used multivariable logistic regression analysis to examine differences in utilization of abiraterone, enzalutamide, and docetaxel between AA and white men. We then used Fine-Gray models with death as a competing risk to assess treatment-specific associations between race and time to next therapy (TTNT) – a proxy for progression-free survival. Finally, we used multivariable Cox proportional hazards analyses to assess for treatment-specific racial disparities in all-cause mortality. All analyses were adjusted for age, Elixhauser comorbidity index, baseline steroid or opioid use (a proxy for disease aggressiveness), performance status, insurance status, and (if significant) an interaction term for race and age. Results: Of 3,808 mCRPC patients in the cohort, 2,165 (68.7%) were white and 404 (10.6%) were AA. At time of metastatic diagnosis, AA men were younger (69 vs. 75, p < 0.001) and more likely to have PSA value greater than 50 (57.9% vs. 42.6%, p < 0.001) compared to white men. Median follow up was 15 months. There were no significant racial differences in 1L utilization, TTNT, or all-cause mortality associated with abiraterone, enzalutamide, or docetaxel use (Table). Conclusions: In this large real-world analysis of men with mCRPC who received 1L therapy, we found no significant treatment-specific differences in utilization, TTNT, or all-cause mortality between AA and white men. Long-term prospective evidence is needed to justify differential treatment selection for AA men with mCRPC. [Table: see text]


2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 245-245
Author(s):  
Johan Chan ◽  
Whee Sze Ong ◽  
Quan Sing Ng ◽  
Chee-Keong Toh ◽  
Tanujaa Rajasekaran ◽  
...  

245 Background: The presence of AR-V7 in metastatic castrate resistant prostate cancer (mCRPC) men has been associated with worse outcome in men initiated on 2nd generation androgen receptor signalling inhibitors (ARSI) in the Caucasian population. A multinational study was conducted to investigate this in the Asian population. Methods: mCRPC patients were recruited prospectively across 5 countries. Blood samples were collected and processed from patients with progressive disease immediately before the initiation of a new treatment and at progression. AR-V7 detection were performed using 3 methods: CTC enrichment followed by automated immunofluorescent staining (Clearbridge [CB]), CTC enrichment followed by reverse-transcription PCR analysis (IBN), and the AdnaTest Prostate Cancer(Adna) platform for CTC analysis and detection. Only blood samples collected in Singapore underwent all 3 methods of detecting AR-V7. Comparison of AR-V7 prevalence using the 3 detection methods were done on patients with the AdnaTest platform as gold standard. We examined associations between AR-V7 status and PSA response rates, PSA progression free survival and overall survival(OS). Results: 102 patients were recruited. 72 patients had ARSi while 30 patients had chemotherapy. 66 patients were included for the comparison of AR-V7 detection methods. AR-V7 prevalence rate was 14.3% (95% CI 4.8-30.3), 21.6% (95% CI 12.9-32.7) and 33.7% (95% CI 24.6-43.8) based on Adna, CB and IBN respectively. Concordance between Adna and CB was 75% while Adna and IBN was 68%. AR-V7- patients had a trend towards higher PSA response, lower risk of PSA progression as compared to AR-V7+ patients. AR-V7- patients had a significantly lower risk of death as compared to AR-V7+ patients detected by Adna and IBN platforms but not the CB platform. The association between ARV7 status and outcomes did not vary when compared across treatment groups. Conclusions: AR-V7 positivity in Asian mCRPC patients is consistent with the data reported in Western populations with lower PSA response rates, PSA progression free survival and OS. This data suggest that ARV7 is more likely a prognostic than a predictive biomarker. Clinical trial information: 2015/2797.


2018 ◽  
Vol 10 (12) ◽  
pp. 445-454 ◽  
Author(s):  
Vadim S. Koshkin ◽  
Eric J. Small

Apalutamide (ARN-509) is a second-generation androgen receptor (AR) antagonist that was developed to inhibit AR-mediated prostate cancer cell proliferation. Following the initial promising clinical efficacy results in phase I and II clinical trials of patients with metastatic castrate-resistant prostate cancer (CRPC), apalutamide has been investigated in several phase III trials. Particular interest has focused on the development of effective therapy for the prevention of disease progression in patients with nonmetastatic (nm or M0) CRPC, especially patients who have a rapid prostate-specific antigen (PSA) doubling time that is indicative of shorter bone metastasis-free survival and associated with significant morbidity and mortality. The results from the phase III SPARTAN trial were recently published and reported a significant benefit of apalutamide relative to placebo in patients with nmCRPC and a high risk of metastatic progression. The study noted marked improvement in the primary endpoint of metastasis-free survival as well as several relevant secondary clinical endpoints, including time to symptomatic progression. These results led to the United States Food and Drug Administration (US FDA) approval of apalutamide in the nmCRPC setting in February 2018. This review summarizes the clinical development of apalutamide, culminating with the pivotal SPARTAN trial as well as other phase III trials which may further expand potential indications for this agent in the near future.


2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Azik Hoffman ◽  
Hiroshi Sasaki ◽  
Domenica Roberto ◽  
Michelle J Mayer ◽  
Laurence Klotz ◽  
...  

Background: This study was designed to assess the efficacy of the combination of Desmopressin and Docetaxel for prostate cancer. Desmopressin has been demonstrated to inhibit tumor progression and metastasis in in vitro and in vivo models of breast cancer. Docetaxel, an anti-mitotic chemotherapeutic agent, is widely used for the treatment of castration resistant prostate cancer. However, it is associated with adverse effects and eventual drug resistance. This is the first report on the effect of combining Desmopressin and Docetaxel in prostate cancer, both in vitro and in vivo. Methods: An established castrate resistant prostate cancer cell line DU145 was used. Cellular proliferation was determined using the MTS assay. The migratory inhibition potential of Desmopressin alone and in combination with Docetaxel was accessed using the wound healing assay. In vivo evaluation was performed on a prostate cancer xenograft model using athymic nude mouse. Treatment was administered bi- weekly and tumor volume were measured throughout the treatment period. Eventually, after a six-week treatment period, tumors were excised and measured.  Results: A combination therapy of 1 µM Desmopressin with 100nM Docetaxel resulted in dramatic inhibition of proliferation of DU145 cells 72 hours post treatment compared to either agent along (p < 0.05). Wound healing assay revealed inhibition of cellular migration as well (p<0.05). The use of a xenograft mouse model followed by treatment with 5 mg/kg Docetaxel intraperitoneally with concomitant 2 µg/ml/kg Desmopressin administered intravenously 30 minutes before administering chemotherapy and 24 hours after, resulted in a significant decrease in tumor volume (P<0.05), while not impacting body weight.Conclusions: Desmopressin significantly enhanced the anti-proliferative and inhibiting the migratory potential of Docetaxel. Combination treatment had no additional effect on mice weight or mortality. These studies could enhance the efficacy of Docetaxel- based chemotherapy treatment for castrate resistant prostate cancer.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 11590-11590 ◽  
Author(s):  
Neil Pegg ◽  
Nigel Brooks ◽  
Jenny Worthington ◽  
Barbara Young ◽  
Amy Prosser ◽  
...  

11590 Background: Targeted degradation of androgen receptor (AR) and AR variants (ARV) remains an attractive therapeutic opportunity for patients with castrate resistant prostate cancer (CRPC). E1A binding protein (p300) and CREB binding protein (CBP) are two closely related transcriptional activators of AR. We have developed CCS1477 which is a potent, selective and orally active small molecule inhibitor of the bromodomain of p300/CBP and investigated its role in regulating androgen receptor expression and function. Methods: Binding of CCS1477 to p300, CBP and BRD4, was measured in a surface plasmon resonance (SPR) assay. Potency and functional activity (proliferation and biomarker knockdown) was demonstrated in prostate cell lines in vitro (22Rv1, VCaP). Cross species in vivo pharmacokinetic (PK) properties were assessed, and in vivo efficacy, linked to inhibition of biomarkers, was determined in 22Rv1 and LNCaP xenograft models. Results: CCS1477 binds to p300 and CBP with high affinity (Kd = 1.3/1.7nM) and selectivity (Kd = 222nM; BRD4). It is a potent inhibitor of cell proliferation in prostate cell lines (IC50 = 96nM,22Rv1; 49nM,VCaP) with minimal effect in AR-ve lines. In 22Rv1 cells, p300/CBP inhibition down-regulates AR-FL, AR-V7 and c-Myc protein by Western, an effect not seen with the BET inhibitor, JQ1 at equivalent proliferation IC50s. Inhibition of p300/CBP also reduces c-Myc, KLK3 and TMPRSS2 gene expression (qPCR) in 22Rv1 cells in vitro. The in vivo PK properties of CCS1477 are consistent with qd or qod oral dosing in mouse. CCS1477 dosed at 10mg, 20mg/kg qd or 30mg/kg qod, caused complete tumour growth inhibition over 28 days in a 22RV1 xenograft model, including extended duration in the absence of the drug for a further 24 days. This was accompanied by complete inhibition of plasma PSA and significant knockdown of tumour AR-FL, AR-V7, and C-Myc protein as well as C-Myc and TMPRSS2 mRNA expression. Conclusions: Taken together these data support the clinical testing of CCS1477 in castrate resistant prostate cancer by down-regulation of AR, AR-SV and c-MYC expression and function.


2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 356-356
Author(s):  
Adam McLain Kase ◽  
Cheryl Cook ◽  
Winston Tan

356 Background: Approval of multiple therapeutic agents for castrate resistant prostate cancer (CPRPC) has improved survival and also quality of life. However, how to optimize sequencing is still an ongoing challenge for most clinicians. Methods: A retrospective chart review of patients treated with FDA approved regimens for castrate resistant prostate cancer from 2002 to 2017 at Mayo Clinical Florida was completed. Data on progression free survival of the various treatment sequences including abiraterone, docetaxel, and enzalutamide were reviewed. Results: One hundred patients were included in the study. Those on clinical trial were excluded. All patients were on LHRH agonist /antagonist and were continued while on the subsequent treatments. The first line therapy progression free survival (PFS) was 245 days with abiraterone acetate (AA), 307 days with enzalutamide (E) and docetaxel 285 days, respectively. The second line therapy PFS was 201 days with AA and 166 days with E. When AA was given after E PFS was 97 days and when E was given after AA the PFS was 68 days. E given after docetaxel resulted in a PFS of 390 days for one patient. Conclusions: In this chart review, enzalutamide had the longest PFS when used as the first line therapy and the PFS was improved when used as a second line after docetaxel. This retrospective review suggests therapy sequencing may be optimized to increase progressive free survival in patients with metastatic castrate resistant prostate cancer.


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