PEG‐PLA nanoparticles decorated with small‐molecule PSMA ligand for targeted delivery of galbanic acid and docetaxel to prostate cancer cells

2019 ◽  
Vol 235 (5) ◽  
pp. 4618-4630 ◽  
Author(s):  
Maryam Afsharzadeh ◽  
Maryam Hashemi ◽  
Maryam Babaei ◽  
Khalil Abnous ◽  
Mohammad Ramezani
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Small Molecule ◽  
Targeted Delivery ◽  
Prostate Cancer Cells ◽  
Psma Ligand ◽  
Galbanic Acid

Identification of a small-molecule inhibitor of Stat5a/b through structure-based screen for therapy development for prostate cancer.

2011 ◽  
Vol 29 (7_suppl) ◽  
pp. 17-17
Author(s):  
Z. Liao ◽  
L. Gu ◽  
F. Shen ◽  
A. Dagvadorj ◽  
S. Gupta ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Small Molecule ◽  
Nuclear Translocation ◽  
Human Prostate ◽  
Prostate Cancer Cells ◽  
Castration Resistant ◽  
Molecule Inhibitor ◽  
Prostate Cancers

17 Background: There are no effective treatments for metastatic or castration resistant prostate cancer. We have shown that transcription factor Stat5a/b is constitutively active in high-grade prostate cancer, but not in normal human prostate epithelium. Stat5a/b is active in 95% of clinical castration resistant prostate cancers, and the expression of active Stat5a/b in primary prostate cancer predicts early disease recurrence. Stat5a/b is critical for the viability of prostate cancer cells in vitro and for growth of prostate xenograft tumors in nude mice. Stat5a/b synergizes with androgen receptor (AR) and Stat5a/b promotes metastatic behavior of human prostate cancer cells in vitro and in vivo. Here, we hypothesize that Stat5a/b is a molecular target for rational drug design for prostate cancer. Methods: We identified a small- molecule inhibitor of Stat5a/b dimerization by structure-based virtual screen from a database of 30 million chemical structures. The efficacy of the Stat5a/b inhibitor was determined by reporter gene assays, dimerization by co-immunoprecipitations, nuclear translocation by cytochemistry and binding to DNA by EMSA. Cell viability was analyzed by MTT assay. Results: The novel Stat5a/b inhibitor IST5-002 inhibited transcriptional activity of Stat5a/b at IC50 of 1.5 μ M for Stat5a and 3.5 μ M for Stat5b, but not of Stat3 in prostate cancer cells. IST5-002 inhibited dimerization, nuclear translocation, and binding of Stat5a/b to the Stat5 DNA consensus sequence. Furthermore, IST5-002 inhibited expression of Stat5a/b target gene cyclin D1, and induced massive apoptosis of DU145, CWR22Rv1 and LNCaP human prostate cancer cells. IST5-002 blocked prostate cancer xenograft tumor growth in nude mice and induced death in clinical prostate cancers ex vivo in 3D organ cultures. Conclusions: We have identified a small molecule Stat5a/b inhibitor IST5-002 for therapy development for prostate cancer. Future work will focus on chemical modifications of IST5-002 to achieve IC50 below 1 μ M and oral administration. No significant financial relationships to disclose.

Preclinical investigation of a small molecule inhibitor of p300/CBP reveals efficacy in patient-derived prostate tumor explants.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e16534-e16534 ◽  
Author(s):  
Lisa Butler ◽  
Swati Irani ◽  
Margaret Centenera ◽  
Natalie Ryan ◽  
Neil Pegg ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Small Molecule ◽  
Single Agent ◽  
Specific Antigen ◽  
Resistance Mechanisms ◽  
Prostate Cancer Cells ◽  
In Vivo Models

e16534 Background: Growth and survival of prostate cancer cells are initially dependent upon androgens, and androgen deprivation therapy (ADT) is used to control tumor growth. Unfortunately, resistance to ADT inevitably occurs, and patients relapse with lethal castrate-resistant prostate cancer (CRPC). Increased expression of the androgen receptor (AR) and constitutively active AR variants are hallmarks of CRPC, and treatments targeting aberrant AR signaling are urgently required. CCS1477 is an inhibitor of p300/CBP currently in a Phase I/IIa study for CRPC. CCS1477 enhances degradation of numerous cellular proteins including the AR and AR variants in prostate cancer cells. Our preclinical studies with this compound demonstrated potent single-agent efficacy of CCS1477 using in vitro and in vivo models of prostate cancer and, when used in combination, CCS1477 enhances the efficacy of enzalutamide, a clinical AR antagonist. Understanding the response of clinical tumors to CCS1477, and their potential adaptive evolution, is essential to personalize treatment and predict potential resistance mechanisms. Methods: To assess CCS1477 in human disease, we used a unique model in which clinical prostate tumors from radical prostatectomy are cultured as explants with maintenance of tissue integrity, cell proliferation and androgen signaling. Tumors from 13 patients were cultured in the absence or presence of CCS1477 (10µM) or enzalutamide (10µM) for 48 or 72 hours; micromolar doses were selected to account for altered small molecule uptake and penetration into tissues compared to cell lines, as previously reported. Proliferation, apoptosis and androgen signaling were all analyzed post-culture. Results: Whereas the tumor explants exhibited highly heterogenous proliferative responses to enzalutamide, tumors from all patients exhibited a marked antiproliferative response to CCS1477 (mean reduction in Ki67 immunoreactivity of > 90% compared to vehicle control; p < 0.0005). Culture with CCS1477 was associated with repression of androgen signaling in the prostate tissues, measured by expression and secretion of the clinical biomarker prostate specific antigen (PSA). Conclusions: The consistent and pronounced efficacy of CCS1477 in this patient-derived model would support further investigation of this class of epigenetic agents in the castrate-sensitive prostate cancer setting.

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