scholarly journals Humanization, Radiolabeling and Biodistribution Studies of an IgG1-Type Antibody Targeting Uncomplexed PSA for Theranostic Applications

2021 ◽  
Vol 14 (12) ◽  
pp. 1251
Author(s):  
Joanna Strand ◽  
Kjell Sjöström ◽  
Urpo J. Lamminmaki ◽  
Oskar Vilhelmsson Timmermand ◽  
Sven-Erik Strand ◽  
...  

Metastatic castration-resistant prostate cancer is today incurable. Conventional imaging methods have limited detection, affecting their ability to give an accurate outcome prognosis, and current therapies for metastatic prostate cancer are insufficient. This inevitably leads to patients relapsing with castration-resistant prostate cancer. Targeting prostate-specific antigens whose expression is closely linked to the activity in the androgen receptor pathway, and thus the pathogenesis of prostate cancer, is a possible way to increase specificity and reduce off-target effects. We have humanized and evaluated radioimmunoconjugates of a previously murine antibody, m5A10, targeting PSA intended for theranostics of hormone-refractory prostate cancer. The humanized antibody h5A10 was expressed in mammalian HEK293 cells transfected with the nucleotide sequences for the heavy and light chains of the antibody. Cell culture medium was filtered and purified by Protein G chromatography, and the buffer was changed to PBS pH 7.4 by dialysis. Murine and humanized 5A10 were conjugated with p-SCN-Bn-CHX-A”-DTPA. Surface plasmon resonance was used to characterize the binding to PSA of the immunoconjugates. Immunoconjugates were labeled with either indium-111 or lutetium-177. Biodistribution studies of murine and humanized 5A10 were performed in mice with LNCaP xenografts. 5A10 was successfully humanized, and in vivo targeting showed specific binding in xenografts. The results thus give an excellent platform for further theranostic development of humanized 5A10 for clinical applications.

Author(s):  
Michelle Naidoo ◽  
Fayola Levine ◽  
Tamara Gillot ◽  
Akintunde T. Orunmuyi ◽  
E. Oluwabunmi Olapade-Olaopa ◽  
...  

High mortality rates of prostate cancer (PCa) are associated with metastatic castration-resistant prostate cancer (CRPC) due to the maintenance of androgen receptor (AR) signaling despite androgen deprivation therapies (ADTs). The 8q24 chromosomal locus is a region of very high PCa susceptibility that carries genetic variants associated with high risk of PCa incidence. This region also carries frequent amplifications of the PVT1 gene, a non-protein coding gene that encodes a cluster of microRNAs including, microRNA-1205 (miR-1205), which are largely understudied. Herein, we demonstrate that miR-1205 is underexpressed in PCa cells and tissues and suppresses CRPC tumors in vivo. To characterize the molecular pathway, we identified and validated fry-like (FRYL) as a direct molecular target of miR-1205 and observed its overexpression in PCa cells and tissues. FRYL is predicted to regulate dendritic branching, which led to the investigation of FRYL in neuroendocrine PCa (NEPC). Resistance toward ADT leads to the progression of treatment related NEPC often characterized by PCa neuroendocrine differentiation (NED), however, this mechanism is poorly understood. Underexpression of miR-1205 is observed when NED is induced in vitro and inhibition of miR-1205 leads to increased expression of NED markers. However, while FRYL is overexpressed during NED, FRYL knockdown did not reduce NED, therefore revealing that miR-1205 induces NED independently of FRYL.


2021 ◽  
Vol 14 (10) ◽  
pp. 1020
Author(s):  
Zohaib Rana ◽  
Sarah Diermeier ◽  
Fearghal P. Walsh ◽  
Muhammad Hanif ◽  
Christian G. Hartinger ◽  
...  

Metastatic castration-resistant prostate cancer (CRPC) has a five-year survival rate of 28%. As histone deacetylases (HDACs) are overexpressed in CRPC, the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) was trialled in CRPC patients but found to be toxic and inefficacious. Previously, we showed that novel HDAC inhibitors (Jazz90 (N1-hydroxy-N8-(4-(pyridine-2-carbothioamido)phenyl)octanediamide) and Jazz167 ([chlorido(η5-pentamethylcyclopentadieny[1–4](N1-hydroxy-N8-(4-(pyridine-2-carbothioamido-κ2N,S)phenyl)octanediamide)rhodium(III)] chloride) had a higher cancer-to-normal-cell selectivity and superior anti-angiogenic effects in CRPC (PC3) cells than SAHA. Thus, this study aimed to further investigate the efficacy and toxicity of these compounds. HUVEC tube formation assays revealed that Jazz90 and Jazz167 significantly reduced meshes and segment lengths in the range of 55–88 and 43–64%, respectively. However, Jazz90 and Jazz167 did not affect the expression of epithelial-to-mesenchymal transitioning markers E-cadherin and vimentin. Jazz90 and Jazz167 significantly inhibited the growth of PC3 and DU145 spheroids and reduced PC3 spheroid branching. Jazz90 and Jazz167 (25, 50 and 75 mg/kg/day orally for 21 days) were non-toxic in male BALB/c mice. The efficacy and safety of these compounds demonstrate their potential for further in vivo studies in CRPC models.


Oncogene ◽  
2014 ◽  
Vol 34 (21) ◽  
pp. 2764-2776 ◽  
Author(s):  
N Jiang ◽  
K Hjorth-Jensen ◽  
O Hekmat ◽  
D Iglesias-Gato ◽  
T Kruse ◽  
...  

2014 ◽  
Vol 28 (10) ◽  
pp. 1629-1639 ◽  
Author(s):  
Yingqiu Xie ◽  
Wenfu Lu ◽  
Shenji Liu ◽  
Qing Yang ◽  
Brett S. Carver ◽  
...  

Castration-resistant prostate cancer (PCa) (CRPC) is relapse after various forms of androgen ablation therapy and causes a major mortality in PCa patients, yet the mechanism remains poorly understood. Here, we report the nuclear form of mesenchymal epithelial transition factor (nMET) is essential for CRPC. Specifically, nMET is remarkably increased in human CRPC samples compared with naïve samples. Androgen deprivation induces endogenous nMET and promotes cell proliferation and stem-like cell self-renewal in androgen-nonresponsive PCa cells. Mechanistically, nMET activates SRY (sex determining region Y)-box9, β-catenin, and Nanog homeobox and promotes sphere formation in the absence of androgen stimulus. Combined treatment of MET and β-catenin enhances the inhibition of PCa cell growth. Importantly, MET accumulation is detected in nucleus of recurrent prostate tumors of castrated Pten/Trp53 null mice, whereas MET elevation is predominantly found in membrane of naïve tumors. Our findings reveal for the first time an essential role of nMET association with SOX9/β-catenin in CRPC in vitro and in vivo, highlighting that nuclear RTK activate cell reprogramming to drive recurrence, and targeting nMET would be a new avenue to treat recurrent cancers.


2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Fu-Ju Chou ◽  
ChangYi Lin ◽  
Hao Tian ◽  
WanYing Lin ◽  
Bosen You ◽  
...  

Abstract The FDA-approved anti-androgen Enzalutamide (Enz) has been used successfully as the last line therapy to extend castration-resistant prostate cancer (CRPC) patients’ survival by an extra 4.8 months. However, CRPC patients eventually develop Enz-resistance that may involve the induction of the androgen receptor (AR) splicing variant ARv7. Here we found that Cisplatin (Cis) or Carboplatin, currently used in chemotherapy/radiation therapy to suppress tumor progression, could restore the Enz sensitivity in multiple Enz-resistant (EnzR) CRPC cells via directly degrading/suppressing the ARv7. Combining Cis or Carboplatin with Enz therapy can also delay the development of Enz-resistance in CRPC C4-2 cells. Mechanism dissection found that Cis or Carboplatin might decrease the ARv7 expression via multiple mechanisms including targeting the lncRNA-Malat1/SF2 RNA splicing complex and increasing ARv7 degradation via altering ubiquitination. Preclinical studies using in vivo mouse model with implanted EnzR1-C4-2 cells also demonstrated that Cis plus Enz therapy resulted in better suppression of EnzR CRPC progression than Enz treatment alone. These results not only unveil the previously unrecognized Cis mechanism to degrade ARv7 via targeting the Malat1/SF2 complex and ubiquitination signals, it may also provide a novel and ready therapy to further suppress the EnzR CRPC progression in the near future.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Peng Xie ◽  
Hongliang Yu ◽  
Feijiang Wang ◽  
Feng Yan ◽  
Xia He

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.


2019 ◽  
Vol 11 (498) ◽  
pp. eaaw4636 ◽  
Author(s):  
Ning Zhao ◽  
Stephanie O. Peacock ◽  
Chen Hao Lo ◽  
Laine M. Heidman ◽  
Meghan A. Rice ◽  
...  

Castration-resistant prostate cancer (CRPC) recurs after androgen deprivation therapy (ADT) and is incurable. Reactivation of androgen receptor (AR) signaling in the low androgen environment of ADT drives CRPC. This AR activity occurs through a variety of mechanisms, including up-regulation of AR coactivators such as VAV3 and expression of constitutively active AR variants such as the clinically relevant AR-V7. AR-V7 lacks a ligand-binding domain and is linked to poor prognosis. We previously showed that VAV3 enhances AR-V7 activity to drive CRPC progression. Gene expression profiling after depletion of either VAV3 or AR-V7 in CRPC cells revealed arginine vasopressin receptor 1a (AVPR1A) as the most commonly down-regulated gene, indicating that this G protein–coupled receptor may be critical for CRPC. Analysis of publicly available human PC datasets showed thatAVPR1Ahas a higher copy number and increased amounts of mRNA in advanced PC. Depletion of AVPR1A in CRPC cells resulted in decreased cell proliferation and reduced cyclin A. In contrast, androgen-dependent PC, AR-negative PC, or nontumorigenic prostate epithelial cells, which have undetectableAVPR1AmRNA, were minimally affected by AVPR1A depletion. Ectopic expression of AVPR1A in androgen-dependent PC cells conferred castration resistance in vitro and in vivo. Furthermore, treatment of CRPC cells with the AVPR1A ligand, arginine vasopressin (AVP), activated ERK and CREB, known promoters of PC progression. A clinically safe and selective AVPR1A antagonist, relcovaptan, prevented CRPC emergence and decreased CRPC orthotopic and bone metastatic growth in mouse models. Based on these preclinical findings, repurposing AVPR1A antagonists is a promising therapeutic approach for CRPC.


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