Treatment of castration-resistant prostate cancer remains a challenging clinical problem. Despite the promising effects of immunotherapy in other solid cancers, prostate cancer has remained largely... Show moreTreatment of castration-resistant prostate cancer remains a challenging clinical problem. Despite the promising effects of immunotherapy in other solid cancers, prostate cancer has remained largely unresponsive. Oncolytic viruses represent a promising therapeutic avenue, as oncolytic virus treatment combines tumour cell lysis with activation of the immune system and mounting of effective anti-tumour responses. Mammalian Orthoreoviruses are non-pathogenic human viruses with a preference of lytic replication in human tumour cells. In this study, we evaluated the oncolytic efficacy of the bioselected oncolytic reovirus mutant jin-3 in multiple human prostate cancer models. The jin-3 reovirus displayed efficient infection, replication, and anti-cancer responses in 2D and 3D prostate cancer models, as well as in ex vivo cultured human tumour slices. In addition, the jin-3 reovirus markedly reduced the viability and growth of human cancer cell lines and patient-derived xenografts. The infection induced the expression of mediators of immunogenic cell death, interferon-stimulated genes, and inflammatory cytokines. Taken together, our data demonstrate that the reovirus mutant jin-3 displays tumour tropism, and induces potent oncolytic and immunomodulatory responses in human prostate cancer models. Therefore, jin-3 reovirus represents an attractive candidate for further development as oncolytic agent for treatment of patients with aggressive localised or advanced prostate cancer. Show less
Reporter genes are used to visualize intracellular biological phenomena, including viral infection. Here we demonstrate bioluminescent imaging of viral infection using the NanoBiT system in... Show moreReporter genes are used to visualize intracellular biological phenomena, including viral infection. Here we demonstrate bioluminescent imaging of viral infection using the NanoBiT system in combination with intraperitoneal injection of a furimazine analogue, hydrofurimazine. This recently developed substrate has enhanced aqueous solubility allowing delivery of higher doses for in vivo imaging. The small high-affinity peptide tag (HiBiT), which is only 11 amino-acids in length, was engineered into a clinically used oncolytic adenovirus, and the complementary large protein (LgBiT) was constitutively expressed in tumor cells. Infection of the LgBiT expressing cells with the HiBiT oncolytic virus will reconstitute NanoLuc in the cytosol of the cell, providing strong bioluminescence upon treatment with substrate. This new bioluminescent system served as an early stage quantitative viral transduction reporter in vitro and also in vivo in mice, for longitudinal monitoring of oncolytic viral persistence in infected tumor cells. This platform provides novel opportunities for studying the biology of viruses in animal models. Show less
Hensbergen, A.W.; Buckle, T.; Willigen, D.M. van; Schottelius, M.; Welling, M.M.; Wijk, F.A. van der; ... ; Leeuwen, F.W.B. van 2020
Prostate cancer surgery is currently being revolutionized by the use of prostate-specific membrane antigen (PSMA)-targeted radiotracers, for example, (99)mTc-labeled PSMA tracer analogs for... Show moreProstate cancer surgery is currently being revolutionized by the use of prostate-specific membrane antigen (PSMA)-targeted radiotracers, for example, (99)mTc-labeled PSMA tracer analogs for radioguided surgery. The purpose of this study was to develop a second-generation (99)mTc-labeled PSMA-targeted tracer incorporating a fluorescent dye. Methods: Several PSMA-targeted hybrid tracers were synthesized: glutamic acid- urea-lysine (EuK)-Cy5-mas(3), EuK-(SO3)Cy5-mas(3), EuK-Cy5(SO3)-mas(3), EuK-(Ar)Cy5-mas(3), and EuK-Cy5(Ar)-mas(3); the Cy5 dye acts as a functional backbone between the EuK targeting vector and the 2-mercaptoacetyl-seryl-seryl-seryl (mas(3)) chelate to study the dye's interaction with PSMA's amphipathic entrance funnel. The compounds were evaluated for their photophysical and chemical properties and PSMA affinity. After radiolabeling with (99)mTc, we performed in vivo SPECT imaging, biodistribution, and fluorescence imaging on BALB/c nude mice with orthotopically transplanted PC346C tumors. Results: The dye composition influenced the photophysical properties (brightness range 0.3-1.5 x 10(4) M-1 x cm(-1)), plasma protein interactions (range 85.0% +/- 2.3%-90.7%+/- 1.3% bound to serum, range 76%+/- 0%-89%+/- 6% stability in serum), PSMA affinity (half-maximal inhibitory concentration [IC50] range 19.2 +/- 5.8-175.3 +/- 61.1 nM) and in vivo characteristics (tumorto-prostate and tumor-to-muscle ratios range 0.02 +/- 0.00-154.73 +/- 28.48 and 0.46 +/- 0.28-5,157.50 +/- 949.17, respectively; renal, splenic, and salivary retention). Even though all tracer analogs allowed tumor identification with SPECT and fluorescence imaging, (99)mTc-EuK(SO3)Cy5-mas(3) had the most promising properties (e.g., half-maximal inhibitory concentration, 19.2 +/- 5.8, tumor-to-muscle ratio, 5,157.50 +/- 949.17). Conclusion: Our findings demonstrate the intrinsic integration of a fluorophore in the pharmacophore in PSMA-targeted smallmolecule tracers. In this design, having 1 sulfonate on the indole moiety adjacent to EuK ((99)mTc-EuK-(SO3)Cy5-mas(3)) yielded the most promising tracer candidate for imaging of PSMA. Show less
Background Methods While it has been challenging to establish prostate cancer patient-derived xenografts (PDXs), with a take rate of 10-40% and long latency time, multiple groups throughout the... Show moreBackground Methods While it has been challenging to establish prostate cancer patient-derived xenografts (PDXs), with a take rate of 10-40% and long latency time, multiple groups throughout the world have developed methods for the successful establishment of serially transplantable human prostate cancer PDXs using a variety of immune deficient mice. In 2014, the Movember Foundation launched a Global Action Plan 1 (GAP1) project to support an international collaborative prostate cancer PDX program involving eleven groups. Between these Movember consortium members, a total of 98 authenticated human prostate cancer PDXs were available for characterization. Eighty three of these were derived directly from patient material, and 15 were derived as variants of patient-derived material via serial passage in androgen deprived hosts. A major goal of the Movember GAP1 PDX project was to provide the prostate cancer research community with a summary of both the basic characteristics of the 98 available authenticated serially transplantable human prostate cancer PDX models and the appropriate contact information for collaborations. Herein, we report a summary of these PDX models. PDX models were established in immunocompromised mice via subcutaneous or subrenal-capsule implantation. Dual-label species (ie, human vs mouse) specific centromere and telomere Fluorescence In Situ Hybridization (FISH) and immuno-histochemical (IHC) staining of tissue microarrays (TMAs) containing replicates of the PDX models were used for characterization of expression of a number of phenotypic markers important for prostate cancer including AR (assessed by IHC and FISH), Ki67, vimentin, RB1, P-Akt, chromogranin A (CgA), p53, ERG, PTEN, PSMA, and epithelial cytokeratins. Results Conclusion Within this series of PDX models, the full spectrum of clinical disease stages is represented, including androgen-sensitive and castration-resistant primary and metastatic prostate adenocarcinomas as well as prostate carcinomas with neuroendocrine differentiation. The annotated clinical characteristics of these PDXs were correlated with their marker expression profile. Our results demonstrate the clinical relevance of this series of PDXs as a platform for both basic science studies and therapeutic discovery/drug development. The present report provides the prostate cancer community with a summary of the basic characteristics and a contact information for collaborations using these models. Show less
Wissing, M.D.; Morree, E.S. de; Dezentje, V.O.; Buijs, J.T.; Krijger, R.R. de; Smit, V.T.H.B.M.; ... ; Pluijm, G. van der 2014
