ABSTRACT
Octadecenyl thiophosphate (OTP), a synthetic analogue of the lysophospholipid growth factor lysophosphatidic acid (LPA), significantly reduces mortality following a lethal dose of LD(80/30) radiation exposure in a mouse model of whole-body irradiation. To facilitate dose scaling between species, we developed a novel liquid chromatography/tandem mass spectrometry (LC-MS/MS) for the preclinical pharmacokinetic characterization of OTP in monkeys. Sample extraction was carried out using a butanol based liquid-liquid extraction method. A partially deuterated OTP analogue was used as internal standard (IS). OTP and IS were separated by reversed-phase liquid chromatography on a C-8 column using 10mM ammonium acetate and acetonitrile. A triple quadrupole mass spectrometer operating in the negative electrospray ionization mode with multiple reaction monitoring was used to detect OTP and IS transitions of m/z 363.1-->95.0 and 403.1-->95.0. The method was applied to determine pharmacokinetic parameters in monkeys receiving a single oral OTP dose (3mg/kg). OTP is readily absorbed with a relatively long half-life which supports further preclinical testing of OTP as a radioprotectant in monkeys.
Subject(s)
Chromatography, Liquid/methods , Organophosphorus Compounds/pharmacokinetics , Radiation-Protective Agents/pharmacokinetics , Tandem Mass Spectrometry/methods , Animals , Butanols/chemistry , Chemical Fractionation , Drug Stability , Female , Linear Models , Macaca mulatta , Organophosphorus Compounds/blood , Radiation-Protective Agents/analysis , Reference Standards , Reproducibility of ResultsABSTRACT
BACKGROUND & AIMS: We recently identified lysophosphatidic acid (LPA) as a potent antiapoptotic agent for the intestinal epithelium. The objective of the present study was to evaluate the effect of octadecenyl thiophosphate (OTP), a novel rationally designed, metabolically stabilized LPA mimic, on radiation-induced apoptosis of intestinal epithelial cells in vitro and in vivo. METHODS: The receptors and signaling pathways activated by OTP were examined in IEC-6 and RH7777 cell lines and wild-type and LPA(1) and LPA(2) knockout mice exposed to different apoptotic stimuli. RESULTS: OTP was more efficacious than LPA in reducing gamma irradiation-, camptothecin-, or tumor necrosis factor alpha/cycloheximide-induced apoptosis and caspase-3-8, and caspase-9 activity in the IEC-6 cell line. In RH7777 cells lacking LPA receptors, OTP selectively protected LPA(2) but not LPA(1) and LPA(3) transfectants. In C57BL/6 and LPA(1) knockout mice exposed to 15 Gy gamma irradiation, orally applied OTP reduced the number of apoptotic bodies and activated caspase-3-positive cells but was ineffective in LPA(2) knockout mice. OTP, with higher efficacy than LPA, enhanced intestinal crypt survival in C57BL/6 mice but was without any effect in LPA(2) knockout mice. Intraperitoneally administered OTP reduced death caused by lethal dose (LD)(100/30) radiation by 50%. CONCLUSIONS: Our data indicate that OTP is a highly effective antiapoptotic agent that engages similar prosurvival pathways to LPA through the LPA(2) receptor subtype.
Subject(s)
Apoptosis/radiation effects , Intestinal Mucosa/radiation effects , Organophosphorus Compounds/pharmacology , Radiation Injuries, Experimental/prevention & control , Receptors, Lysophosphatidic Acid/physiology , Administration, Oral , Animals , Apoptosis/drug effects , Apoptosis/physiology , Cell Line , Cells, Cultured , Dose-Response Relationship, Drug , Female , GTP-Binding Proteins/physiology , Gamma Rays/adverse effects , Gene Expression Regulation , Injections, Intraperitoneal , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitogen-Activated Protein Kinases/physiology , Nerve Tissue Proteins/pharmacology , Organophosphorus Compounds/administration & dosage , Phosphatidylinositol 3-Kinases/physiology , Radiation Injuries, Experimental/metabolism , Radiation Injuries, Experimental/pathology , Receptors, Lysophosphatidic Acid/genetics , Signal Transduction/physiology , Tumor Necrosis Factor-alpha/pharmacologyABSTRACT
UNLABELLED: New drugs are urgently needed for improved therapy for melanoma. MATERIALS AND METHODS: Ninety-one novel compounds were evaluated in two melanoma and one normal skin cell lines to identify potential lead compounds with high potency and selectivity. Mechanisms of action for the best compound were also investigated. RESULTS: Three potent lead structures (serine amino alcohols, serine amides and thiazolidines) were identified, with thiazolidines having both excellent potency and high selectivity when compared with sorafenib, a drug used extensively in clinical trials for melanoma. Analyzing the effect of the lead compound showed that it induced DNA degradation consistent with necrotic cell death. CONCLUSION: The lead structure represents a novel class of compounds that can be further optimized for potential drug to treat advanced melanoma.
Subject(s)
Amides/chemistry , Amides/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Melanoma/drug therapy , Thiazolidines/chemistry , Thiazolidines/pharmacology , Benzenesulfonates/pharmacology , Cell Death/drug effects , Cell Growth Processes/drug effects , Cell Line, Tumor , Humans , Inhibitory Concentration 50 , Melanoma/pathology , Necrosis , Niacinamide/analogs & derivatives , Phenylurea Compounds , Pyridines/pharmacology , Sorafenib , Structure-Activity RelationshipABSTRACT
Darmstoff describes a family of gut smooth muscle-stimulating acetal phosphatidic acids initially isolated and characterized from the bath fluid of stimulated gut over 50 years ago. Despite similar structural and biological profiles, Darmstoff analogs have not previously been examined as potential LPA mimetics. Here, we report a facile method for the synthesis of potassium salts of Darmstoff analogs. To understand the effect of stereochemistry on lysophosphatidic acid mimetic activity, synthesis of optically pure stereoisomers of selected Darmstoff analogs was achieved starting with chiral methyl glycerates. Each Darmstoff analog was evaluated for subtype-specific LPA receptor agonist/antagonist activity, PPARgamma activation, and autotaxin inhibition. From this study we identified compound 12 as a pan-antagonist and several pan-agonists for the LPA(1-3) receptors. Introduction of an aromatic ring in the lipid chain such as analog 22 produced a subtype-specific LPA(3) agonist with an EC(50) of 692 nM. Interestingly, regardless of their LPA(1/2/3) ligand properties all of the Darmstoff analogs tested activated PPARgamma. However, these compounds are weak inhibitors of autotaxin. The results indicate that Darmstoff analogs constitute a novel class of lysophosphatidic acid mimetics.
Subject(s)
Phosphatidic Acids/pharmacology , Receptors, Lysophosphatidic Acid/agonists , Receptors, Lysophosphatidic Acid/antagonists & inhibitors , Animals , Cell Line , Drug Evaluation, Preclinical , In Vitro Techniques , Ligands , Molecular Conformation , PPAR gamma/drug effects , Phosphatidic Acids/chemical synthesis , Phosphatidic Acids/chemistry , Stereoisomerism , Structure-Activity RelationshipABSTRACT
In our continuing efforts to develop novel chemotherapeutic agents for prostate cancer, recently we reported the discovery of 2-arylthiazolidine-4-carboxylic acid amides (ATCAAs) as a new class of cytotoxic agents. Several of them were very effective in killing specific human prostate cancer cell lines with low/sub-micromolar cytotoxicity and high selectivity against control cells in our sulforhodamine B assay. Encouraged with these preliminary results, we decided to further optimize this new scaffold to enhance the potency and selectivity. Current work describes the synthesis, SAR, and biological evaluation of new compounds for their ability to inhibit the growth of five human prostate cancer cell lines. The cytotoxicity data demonstrated that ATCAAs are sensitive to simple modifications or changes, which allowed us to understand the minimum structural requirements of this class of compounds to exhibit potent and selective anticancer activity against prostate cancer cells.
Subject(s)
Amides/chemistry , Amides/toxicity , Antineoplastic Agents/chemistry , Antineoplastic Agents/toxicity , Carboxylic Acids/chemistry , Prostatic Neoplasms/pathology , Amides/pharmacology , Antineoplastic Agents/classification , Antineoplastic Agents/pharmacology , Cell Line , Cell Proliferation/drug effects , Humans , Inhibitory Concentration 50 , Male , Molecular Structure , Structure-Activity RelationshipABSTRACT
To improve the selectivity and antiproliferative activity of previously reported serine amide phosphates (SAPs), we designed a new series of 4-thiazolidinone amides, in which the 4-thiazolidinone moiety was introduced as a phosphate mimic. However, these 4-thiazolidinone derivatives demonstrated less cytotoxicity in prostate cancer cells despite improved selectivity over RH7777 cells. To further optimize the thiazolidinone analogues in terms of cytotoxicity and selectivity, we made closely related structural modifications, which led us to the discovery of a new class of 2-arylthiazolidine-4-carboxylic acid amides. These compounds were potent cytotoxic agents with IC(50) values in the low micromolar concentration range and demonstrated enhanced selectivity in receptor-negative cells compared to SAPs and 4-thiazolidinone amides.
Subject(s)
Amides/chemical synthesis , Antineoplastic Agents/chemical synthesis , Thiazoles/chemical synthesis , Amides/chemistry , Amides/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Apoptosis , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , Inhibitory Concentration 50 , Male , Prostatic Neoplasms/drug therapy , RNA, Messenger/biosynthesis , Receptors, Lysophosphatidic Acid/biosynthesis , Receptors, Lysophosphatidic Acid/genetics , Reverse Transcriptase Polymerase Chain Reaction , Structure-Activity Relationship , Thiazoles/chemistry , Thiazoles/pharmacologyABSTRACT
We have previously described serine amide phosphates (SAPs) as a novel class of cytotoxic agents for prostate cancer. Several of them showed potent cytotoxicity against human prostate cancer cell lines, but were not selective in non-tumor cells. To improve the selectivity and further enhance the potency, we designed a new series of 2-aryl-4-oxo-thiazolidin-3-yl amides. The current work describes synthesis, SAR, and biological evaluation of these compounds for their ability to inhibit the growth of prostate cancer cells. The antiproliferative effects of synthesized compounds were examined in five human prostate cancer cell lines (DU-145, PC-3, LNCaP, PPC-1, and TSU), and in RH7777 cells (negative controls). From this study, three potent compounds (8, 20, and 21) have been detected, which are effective in killing prostate cancer cells with improved selectivity compared to SAPs.
Subject(s)
Amides/chemical synthesis , Antineoplastic Agents/chemical synthesis , Thiazoles/chemical synthesis , Amides/chemistry , Amides/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Drug Screening Assays, Antitumor , Humans , Male , Prostatic Neoplasms , Structure-Activity Relationship , Thiazoles/chemistry , Thiazoles/pharmacologyABSTRACT
We describe herein synthesis, SAR, and biological evaluation of a novel series of cytotoxic serine amide phosphates (SAPs) for prostate cancer. These compounds were tested for their cytotoxicity in five human prostate cancer cell lines (DU-145, PC-3, LNCaP, PPC-1, and TSU), and in CHO and RH7777 cells (negative controls). Comparison of anticancer effects of these compounds with a standard chemotherapeutic agent 5-fluorouracil shows that they are very effective in killing prostate cancer cells with low micromolar cytotoxicity and provide us a new lead for the development of drugs for prostate cancer.
