PSMA-D4 Radioligand for Targeted Therapy of Prostate Cancer: Synthesis, Characteristics and Preliminary Assessment of Biological Properties

A new PSMA ligand (PSMA-D4) containing the Glu-CO-Lys pharmacophore connected with a new linker system (L-Trp-4-Amc) and chelator DOTA was developed for radiolabeling with therapeutic radionuclides. Herein we describe the synthesis, radiolabeling, and preliminary biological evaluation of the novel PSMA-D4 ligand. Synthesized PSMA-D4 was characterized using TOF-ESI-MS, NMR, and HPLC methods. The novel compound was subject to molecular modeling with GCP-II to compare its binding mode to analogous reference compounds. The radiolabeling efficiency of PSMA-D4 with 177Lu, 90Y, 47Sc, and 225Ac was chromatographically tested. In vitro studies were carried out in PSMA-positive LNCaP tumor cells membranes. The ex vivo tissue distribution profile of the radioligands and Cerenkov luminescence imaging (CLI) was studied in LNCaP tumor-bearing mice. PSMA-D4 was synthesized in 24% yield and purity >97%. The radio complexes were obtained with high yields (>97%) and molar activity ranging from 0.11 to 17.2 GBq mcmol−1, depending on the radionuclide. In vitro assays confirmed high specific binding and affinity for all radiocomplexes. Biodistribution and imaging studies revealed high accumulation in LNCaP tumor xenografts and rapid clearance of radiocomplexes from blood and non-target tissues. These render PSMA-D4 a promising ligand for targeted therapy of prostate cancer (PCa) metastases.

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Synthesis and Evaluation of the Tetracyclic Ring-System of Isocryptolepine and Regioiso-Mers for Antimalarial, Antiproliferative and Antimicrobial Activities

Molecules ◽

10.3390/molecules26113268 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3268

Author(s):

Katja S. Håheim ◽

Emil Lindbäck ◽

Kah Ni Tan ◽

Marte Albrigtsen ◽

Ida T. Urdal Helgeland ◽

...

Keyword(s):

Prostate Cancer ◽

Cell Lines ◽

Cancer Cell ◽

Antimicrobial Activities ◽

Ring System ◽

Human Prostate ◽

The Novel ◽

Human Prostate Cancer ◽

Biofilm Inhibition

A series of novel quinoline-based tetracyclic ring-systems were synthesized and evaluated in vitro for their antiplasmodial, antiproliferative and antimicrobial activities. The novel hydroiodide salts 10 and 21 showed the most promising antiplasmodial inhibition, with compound 10 displaying higher selectivity than the employed standards. The antiproliferative assay revealed novel pyridophenanthridine 4b to be significantly more active against human prostate cancer (IC50 = 24 nM) than Puromycin (IC50 = 270 nM) and Doxorubicin (IC50 = 830 nM), which are used for clinical treatment. Pyridocarbazoles 9 was also moderately effective against all the employed cancer cell lines and moreover showed excellent biofilm inhibition (9a: MBIC = 100 µM; 9b: MBIC = 100 µM).

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Development of 18F-Labeled Radiotracers for PET Imaging of the Adenosine A2A Receptor: Synthesis, Radiolabeling and Preliminary Biological Evaluation

International Journal of Molecular Sciences ◽

10.3390/ijms22052285 ◽

2021 ◽

Vol 22 (5) ◽

pp. 2285

Author(s):

Thu Hang Lai ◽

Susann Schröder ◽

Magali Toussaint ◽

Sladjana Dukić-Stefanović ◽

Mathias Kranz ◽

...

Keyword(s):

Specific Binding ◽

Brain Slices ◽

Total Activity ◽

Biological Evaluation ◽

Adenosine A2a Receptor ◽

Positron Emission ◽

A2a Receptor ◽

Adenosine A2a

The adenosine A2A receptor (A2AR) represents a potential therapeutic target for neurodegenerative diseases. Aiming at the development of a positron emission tomography (PET) radiotracer to monitor changes of receptor density and/or occupancy during the A2AR-tailored therapy, we designed a library of fluorinated analogs based on a recently published lead compound (PPY). Among those, the highly affine 4-fluorobenzyl derivate (PPY1; Ki(hA2AR) = 5.3 nM) and the 2-fluorobenzyl derivate (PPY2; Ki(hA2AR) = 2.1 nM) were chosen for 18F-labeling via an alcohol-enhanced copper-mediated procedure starting from the corresponding boronic acid pinacol ester precursors. Investigations of the metabolic stability of [18F]PPY1 and [18F]PPY2 in CD-1 mice by radio-HPLC analysis revealed parent fractions of more than 76% of total activity in the brain. Specific binding of [18F]PPY2 on mice brain slices was demonstrated by in vitro autoradiography. In vivo PET/magnetic resonance imaging (MRI) studies in CD-1 mice revealed a reasonable high initial brain uptake for both radiotracers, followed by a fast clearance.

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Comparison of Four SARS-CoV-2 Neutralization Assays

Vaccines ◽

10.3390/vaccines9010013 ◽

2020 ◽

Vol 9 (1) ◽

pp. 13

Author(s):

Lydia Riepler ◽

Annika Rössler ◽

Albert Falch ◽

André Volland ◽

Wegene Borena ◽

...

Keyword(s):

Vesicular Stomatitis Virus ◽

Neutralizing Antibodies ◽

The Other ◽

In Vitro Assays ◽

The Novel ◽

Effective Protection ◽

Vaccine Candidates ◽

Vesicular Stomatitis ◽

Novel Coronavirus

Neutralizing antibodies are a major correlate of protection for many viruses including the novel coronavirus SARS-CoV-2. Thus, vaccine candidates should potently induce neutralizing antibodies to render effective protection from infection. A variety of in vitro assays for the detection of SARS-CoV-2 neutralizing antibodies has been described. However, validation of the different assays against each other is important to allow comparison of different studies. Here, we compared four different SARS-CoV-2 neutralization assays using the same set of patient samples. Two assays used replication competent SARS-CoV-2, a focus forming assay and a TCID50-based assay, while the other two assays used replication defective lentiviral or vesicular stomatitis virus (VSV)-based particles pseudotyped with SARS-CoV-2 spike. All assays were robust and produced highly reproducible neutralization titers. Titers of neutralizing antibodies correlated well between the different assays and with the titers of SARS-CoV-2 S-protein binding antibodies detected in an ELISA. Our study showed that commonly used SARS-CoV-2 neutralization assays are robust and that results obtained with different assays are comparable.

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Fishing for Targets of Alien Metabolites: A Novel Peroxisome Proliferator-Activated Receptor (PPAR) Agonist from a Marine Pest

Marine Drugs ◽

10.3390/md16110431 ◽

2018 ◽

Vol 16 (11) ◽

pp. 431 ◽

Cited By ~ 12

Author(s):

Rosa Vitale ◽

Enrico D'Aniello ◽

Stefania Gorbi ◽

Andrea Martella ◽

Cristoforo Silvestri ◽

...

Keyword(s):

Native Species ◽

Molecular Mechanisms ◽

Ex Vivo ◽

Invasion Biology ◽

In Vitro Assays ◽

Bioactive Metabolites ◽

Peroxisome Proliferator ◽

Invasive Pests

Although the chemical warfare between invasive and native species has become a central problem in invasion biology, the molecular mechanisms by which bioactive metabolites from invasive pests influence local communities remain poorly characterized. This study demonstrates that the alkaloid caulerpin (CAU)—a bioactive component of the green alga Caulerpa cylindracea that has invaded the entire Mediterranean basin—is an agonist of peroxisome proliferator-activated receptors (PPARs). Our interdisciplinary study started with the in silico prediction of the ligand-protein interaction, which was then validated by in vivo, ex vivo and in vitro assays. On the basis of these results, we candidate CAU as a causal factor of the metabolic and behavioural disorders observed in Diplodus sargus, a native edible fish of high ecological and commercial relevance, feeding on C. cylindracea. Moreover, given the considerable interest in PPAR activators for the treatment of relevant human diseases, our findings are also discussed in terms of a possible nutraceutical/pharmacological valorisation of the invasive algal biomasses, supporting an innovative strategy for conserving biodiversity as an alternative to unrealistic campaigns for the eradication of invasive pests.

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Kisspeptin-10 Inhibits Angiogenesis in Human Placental Vessels ex Vivo and Endothelial Cells in Vitro

Endocrinology ◽

10.1210/en.2010-0565 ◽

2010 ◽

Vol 151 (12) ◽

pp. 5927-5934 ◽

Cited By ~ 32

Author(s):

Thayalini Ramaesh ◽

James J. Logie ◽

Antonia K. Roseweir ◽

Robert P. Millar ◽

Brian R. Walker ◽

...

Keyword(s):

Endothelial Cells ◽

Blood Vessels ◽

Ex Vivo ◽

Umbilical Vein ◽

Biologically Active ◽

Trophoblast Invasion ◽

In Vitro Assays ◽

Dependent Manner ◽

Inhibition Of Proliferation

Recent studies suggest that kisspeptin (a neuropeptide central to the regulation of gonadotrophin secretion) has diverse roles in human physiology, including a putative role in implantation and placental function. Kisspeptin and its receptor are present in human blood vessels, where they mediate vasoconstriction, and kisspeptin is known to inhibit tumor metastasis and trophoblast invasion, both processes involving angiogenesis. We hypothesized that kisspeptin contributes to the regulation of angiogenesis in the reproductive system. The presence of the kisspeptin receptor was confirmed in human placental blood vessels and human umbilical vein endothelial cells (HUVEC) using immunochemistry. The ability of kisspeptin-10 (KP-10) (a shorter biologically active processed peptide) to inhibit angiogenesis was tested in explanted human placental arteries and HUVEC using complementary ex vivo and in vitro assays. KP-10 inhibited new vessel sprouting from placental arteries embedded in Matrigel and tube-like structure formation by HUVEC, in a concentration-dependent manner. KP-10 had no effect on HUVEC viability or apoptosis but induced concentration-dependent inhibition of proliferation and migration. In conclusion, KP-10 has antiangiogenic effects and, given its high expression in the placenta, may contribute to the regulation of angiogenesis in this tissue.

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Synthesis, gallium-68 radiolabelling and biological evaluation of a series of triarylphosphonium-functionalized DO3A chelators

Dalton Transactions ◽

10.1039/c8dt02966k ◽

2018 ◽

Vol 47 (43) ◽

pp. 15448-15457 ◽

Cited By ~ 2

Author(s):

Adam J. Smith ◽

Peter J. Gawne ◽

Michelle T. Ma ◽

Philip J. Blower ◽

Richard Southworth ◽

...

Keyword(s):

Ex Vivo ◽

Biological Evaluation ◽

Tumour Cells ◽

Isolated Hearts ◽

Gallium 68

Gallium-68 chelators with tunable lipophilicities were synthesised, and assessed in both in vitro tumour cells and ex vivo isolated hearts.

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EVALUATION OF [11C]MPC-6827 AS A MICROTUBULE TARGETING PET RADIOTRACER IN CANCER CELL LINES

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2020v12i1.35657 ◽

2019 ◽

pp. 43-47

Author(s):

J. S. DILEEP KUMAR ◽

JAYA PRABHAKARAN ◽

NARESH DAMUKA ◽

JUSTIN W. HINES ◽

STEVEN J. KRIDEL ◽

...

Keyword(s):

Breast Cancer ◽

Prostate Cancer ◽

Cell Lines ◽

Cancer Cell ◽

Specific Binding ◽

Cancer Cell Line ◽

Prostate Cancer Cell Line ◽

Microtubule Targeting Agents ◽

Pc3 Cells

Objective: The objective of this study was to evaluate the uptake and specificity of [11C]MPC-6827, a MT targeted PET ligand in prostate, glioblastoma and breast cancer cells. Methods: [11C]MPC-6827 was synthesized by reacting corresponding desmethyl precursors with [11C]CH3I in a GE-FX2MeI/FX2M radiochemistry module. In vitro binding of [11C]MPC-6827 was performed in breast cancer MDA-MB-231, glioblastoma (GBM) patient-derived tumor (GBM-PDX), GBM U251 and prostate cancer 3 (PC3) cell lines at 37 °C in quadruplicate at 5, 15, 30, 60, and 90 minute incubation time. The nonspecific bindings were determined by incubation with unlabeled microtubule targeting agents MPC-6827, HD-800, colchicine, paclitaxel and docetaxel (5.0 mM). Results: [11C]MPC-6827 provided the highest binding in the breast cancer cell, MDA-MB-231, among all the cells studied, with 90% specific binding. [11C]MPC-6827 binds to glioblastoma PDX and U251 cells with ~50% and 40% specific binding, whereas, prostate cancer cell line, PC3 cells showed 40% specific binding. [11C]MPC-6827 also exhibits binding to the taxane and colchicine binding sites of MTs, in MDA-MB-231 cells. Conclusion: These data indicate that [11C]MPC-6827 can be a promising PET radiotracer for preclinical imaging of the brain and peripheral cancers.

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Pharmacological Inhibition of NFκB Reduces Prostate Cancer Related Osteoclastogenesis In Vitro and Osteolysis Ex Vivo

Calcified Tissue International ◽

10.1007/s00223-019-00538-9 ◽

2019 ◽

Vol 105 (2) ◽

pp. 193-204 ◽

Cited By ~ 3

Author(s):

Silvia Marino ◽

Ryan T. Bishop ◽

Giovana Carrasco ◽

John G. Logan ◽

Boya Li ◽

...

Keyword(s):

Prostate Cancer ◽

Ex Vivo ◽

Pharmacological Inhibition

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Conditionally Reprogrammed Cells from Patient-Derived Xenograft to Model Neuroendocrine Prostate Cancer Development

Cells ◽

10.3390/cells9061398 ◽

2020 ◽

Vol 9 (6) ◽

pp. 1398 ◽

Cited By ~ 2

Author(s):

Xinpei Ci ◽

Jun Hao ◽

Xin Dong ◽

Hui Xue ◽

Rebecca Wu ◽

...

Keyword(s):

Prostate Cancer ◽

Ex Vivo ◽

Cancer Cell Line ◽

Marker Genes ◽

Patient Derived Xenograft ◽

Pdx Model ◽

Neuroendocrine Prostate Cancer ◽

Parental Tumor

Neuroendocrine prostate cancer (NEPC) is a lethal subtype of prostate cancer. It develops mainly via NE transdifferentiation of prostate adenocarcinoma in response to androgen receptor (AR)-inhibition therapy. The study of NEPC development has been hampered by a lack of clinically relevant models. We previously established a unique and first-in-field patient-derived xenograft (PDX) model of adenocarcinoma (LTL331)-to-NEPC (LTL331R) transdifferentiation. In this study, we applied conditional reprogramming (CR) culture to establish a LTL331 PDX-derived cancer cell line named LTL331_CR_Cell. These cells retain the same genomic mutations as the LTL331 parental tumor. They can be continuously propagated in vitro and can be genetically manipulated. Androgen deprivation treatment on LTL331_CR_Cells had no effect on cell proliferation. Transcriptomic analyses comparing the LTL331_CR_Cell to its parental tumor revealed a profound downregulation of the androgen response pathway and an upregulation of stem and basal cell marker genes. The transcriptome of LTL331_CR_Cells partially resembles that of post-castrated LTL331 xenografts in mice. Notably, when grafted under the renal capsules of male NOD/SCID mice, LTL331_CR_Cells spontaneously gave rise to NEPC tumors. This is evidenced by the histological expression of the NE marker CD56 and the loss of adenocarcinoma markers such as PSA. Transcriptomic analyses of the newly developed NEPC tumors further demonstrate marked enrichment of NEPC signature genes and loss of AR signaling genes. This study provides a novel research tool derived from a unique PDX model. It allows for the investigation of mechanisms underlying NEPC development by enabling gene manipulations ex vivo and subsequent functional evaluations in vivo.

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Predicting drug pharmacokinetics in humans from in vitro metabolism studies

Biochemical Society Transactions ◽

10.1042/bst0290135 ◽

2001 ◽

Vol 29 (2) ◽

pp. 135-139 ◽

Cited By ~ 34

Author(s):

D. F. McGinnity ◽

R. J. Riley

Keyword(s):

Specific Binding ◽

Liver Microsomes ◽

Intrinsic Clearance ◽

In Vitro Assays ◽

Recombinant Enzymes ◽

Pharmacokinetic Properties ◽

Ic50 Values ◽

Drug Oxidation ◽

Cyp Inhibition

The pharmaceutical industry is committed to market safer drugs with fewer side effects, predictable pharmacokinetic properties and quantifiable drug-drug interactions. There is an increasing need to develop robust, enhanced-throughput in vitro assays, which accurately extrapolate to humans. The major drug metabolizing human hepatic cytochrome P450s (CYPs; CYP1A2, 2C9, 2C19, 2D6 and 3A4) have been co-expressed functionally in Escherichia coli with human NADPH-cytochrome P450 reductase and validated as surrogates to their counterparts in human liver microsomes (HLM) with respect to their kinetic and inhibition properties. Using these recombinant enzymes, fully automated in vitro assays to assess CYP inhibition and determine the enzymology of drug oxidation have been developed and validated. IC50 values determined for a series of test compounds in HLM and recombinant CYPs were similar (r2 = 0.9, P < 0.001). There was a good correlation between the sum of individual CYP intrinsic clearance (Clint) and HLM CIint (r2 = 0.8, P< 0.001) for ten prototypic substrates for which clearance was CYP-dependent. Several in vitro incubation milieu (e.g. CYPs, HLM, human hepatocytes) are routinely used and the level of non-specific binding was investigated with respect to effects on Km and Ki determinations. There were clear correlations between binding and lipophilicity (logD7.4) for a selection of bases (r2 = 0.98, P < 0.001) and acids (r2 = 0.79, P < 0.001) that may allow prediction of this property. Our laboratory has shown that recombinant enzymes are suitable for ‘frontline’ predictive human metabolism studies in early drug discovery.

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