Third generation quinoline-3-carboxamide transcriptional disrupter of HDAC4, HIF-1α, and MEF-2 signaling for metastatic castration-resistant prostate cancer.

Background: The quinoline-3-carboxamide, Tasquinimod (TasQ), is orally active as a maintenance therapy with an on-target mechanism-of-action via allosteric binding to HDAC4. This prevents formation of the HDAC4/NCoR1/HDAC3 complex, disrupting HIF-1α transcriptional activation and repressing MEF-2 target genes needed for adaptive survival signaling in the compromised tumor micro environment. In phase 3 clinical testing against metastatic castration-resistant prostate cancer(mCRPC), TasQ (1 mg/day) increased time-to-progression, but not overall survival.

Albumin-linked prostate-specific antigen-activated thapsigargin- and niclosamide-based molecular grenades targeting the microenvironment in metastatic castration-resistant prostate cancer.

Localized prostate cancer is curable via annihilation of the entire cancer neighborhood by surgery or local radiation. Unfortunately, once metastatic, no available therapy is curative. The vast majority will die despite aggressive systemic combinational androgen-ablation therapies.

2-fluoro-5-maleimidobenzoic acid-linked albumin drug (MAD) delivery for selective systemic targeting of metastatic prostate cancer.

Background: The SH-group at Cys-34 of human serum albumin (HSA) is a unique and accessible functional group that can be exploited for efficient linkage of a maleimide containing cytotoxic drug derivative to albumin. The specific maleimide chemistry used for production of the maleimide-linked albumin drug (MAD) is critical, however, to minimize the plasma concentration of "free" cytotoxic drug spontaneously released from albumin carrier thus decreasing dose-limiting host toxicity while enhancing the plasma half-life from minutes to days (ie, pharmacokinetic effect) and tissue concentration of the MAD in the extracellular cellular fluid at sites of cancer (ie, EPR effect).

Methods: To accomplish this goal, a chemical synthesis was developed using 2-fluoro-5-maleimidobenzoic acid to stably link the potent cytotoxic chemically modified analogue of the naturally occurring sesquiterpene γ-lactone, thapsigargin, 8-O-(12-aminododecanoyl)-8-O-debutanoyl thapsigargin (12ADT), to Cys-34 of albumin to produce 12ADT-MAD.

Anticancer activities of emetine prodrugs that are proteolytically activated by the prostate specific antigen (PSA) and evaluation of in vivo toxicity of emetine derivatives.

Emetine is a small molecule protein synthesis inhibitor that is toxic to all cell types and therefore suitable for complete killing of all types of heterogeneous cancer cells within a tumor. It becomes significantly inactive (non-toxic) when derivatized at its N-2' secondary amine. This provides a strategy for targeting emetine to cancerous tumor without killing normal cells.

Iterative design of emetine-based prodrug targeting fibroblast activation protein (FAP) and dipeptidyl peptidase IV DPPIV using a tandem enzymatic activation strategy.

Background: There is an urgent need to develop new agents for treating metastatic prostate cancer to overcome multiple drug resistance to the current standard targeted cancer therapy. Emetine is a highly cytotoxic natural product protein synthesis inhibitor, which is toxic to all cell types. Its cytotoxicity can be blocked by derivatizing its N-2' position.

Apoptotic Effects of Novel Dithiocarbamate Analogs of Emetine in Prostate Cancer Cell Lines.

Background/aim: Prostate cancer is one of the leading causes of death in American males. Emetine, a naturally-derived alkaloid from the Ipecacuanha plant, has been shown to have potential for anti-tumorigenic effects for cancer treatments. The objective of this study was to characterize novel emetine dithiocarbamate (EMTDTC) analogs for potent anti-tumorigenic activity with minimal toxicity to normal prostate cells and identify targeted apoptotic regulatory genes.

Design, synthesis and cytotoxicity studies of dithiocarbamate ester derivatives of emetine in prostate cancer cell lines.

A small library of emetine dithiocarbamate ester derivatives were synthesized in 25-86% yield via derivatization of the N2'- position of emetine. Anticancer evaluation of these compounds in androgen receptor positive LNCaP and androgen receptor negative PC3 and DU145 prostate cancer cell lines revealed time dependent and dose-dependent cytotoxicity. With the exception of compound 4c, all the dithiocarbamate ester analogs in this study showed appreciable potency in all the prostate cancer cell lines (regardless of whether it is androgen receptor positive or negative) with a cytotoxicity IC50 value ranging from 1.

4-Hy-droxy-5-meth-oxy-N,1-dimethyl-2-oxo-N-[4-(tri-fluoro-meth-yl)phen-yl]-1,2-di-hydro-quinoline-3-carboxamide.

The title compound, C20H17F3N2O4, named tasquinimod, is a second-generation oral quinoline-3-carboxamide analogue, which is currently in phase III clinical trials for the treatment of metastatic prostate cancer. The quinoline unit is almost planar (r.m.

Synthesis and characterization of novel unsymmetrical and symmetrical 3-halo- or 3-methoxy-substituted 2-dibenzoylamino-1,4-naphthoquinone derivatives.

Symmetrical and unsymmetrical 3-halo- or 3-methoxy- substituted 2-dibenzoylamino- 1,4-naphthoquinone analogs were synthesized with an average yield of 45% via sodium hydride promoted bis-acylation of 2-amino-3-chloro-1,4-naphthoquinone, 2-amino-3-bromo-1,4-naphthoquinone and 2-amino-3-methoxy-1,4-naphthoquinone.

Design, synthesis, and evaluation of pH-dependent hydrolyzable emetine analogues as treatment for prostate cancer.

The N-2' position of the natural product emetine has been derivatized to thiourea, urea, sulfonamide, dithiocarbamate, carbamate, and pH responsive hydrolyzable amide analogues. In vitro studies of these analogues in PC3 and LNCaP prostate cancer cell lines showed that the analogues are generally less cytotoxic (average IC(50) ranging from 0.079 to 10 μM) than emetine (IC(50) ranging from 0.

Antitrypanosomal activities and cytotoxicity of some novel imido-substituted 1,4-naphthoquinone derivatives.

The antitrypanosomal activities, cytotoxicity, and selectivity indices of eleven imido-substituted 1,4-naphthoquinone derivatives and nifurtimox have been studied. Compared to nifurtimox (IC(50) = 10.67 μM), all the imido-naphthoquinone analogs (IMDNQ1-IMDNQ11) are more potent on Trypanosoma cruzi with IC50 values ranging from 0.

N-(3-Bromo-1,4-dioxo-1,4-dihydro-2-naphth-yl)-4-fluoro-N-(4-fluoro-benzo-yl)benzamide.

In the title compound, C(24)H(12)BrF(2)NO(4), synthesized from 2-amino-3-bromo-1,4-naphthoquinone and 4-fluoro-benzoyl chloride, the two p-fluoro-phenyl rings are inclined at 73.9 (1) and 73.6 (1)° to the naphthoquinone ring system.

N-(3-Bromo-1,4-dioxo-1,4-dihydro-2-naphth-yl)-2-chloro-N-(2-chloro-benzoyl)benzamide.

The title compound, C(24)H(12)BrCl(2)NO(4), was synthesized from 2-amino-3-bromo-1,4-naphthoquinone and 2-chloro-benzoyl chloride. The crystal structure shows that each of the chloro-phenyl rings is inclined at about 60° to the naphthoquinone ring system. The two chloro-phenyl rings adopt a conformation that ensures that chlorine substituents are anti so as to reduce electronic repulsion.