N-Hydroxyformamide LpxC inhibitors, their in vivo efficacy in a mouse Escherichia coli infection model, and their safety in a rat hemodynamic assay.

UDP-3-O-(R-3-hydroxyacyl)-N-acetylglucosamine deacetylase (LpxC), the zinc metalloenzyme catalyzing the first committed step of lipid A biosynthesis in Gram-negative bacteria, has been a target for antibacterial drug discovery for many years. All inhibitor chemotypes reaching an advanced preclinical stage and clinical phase 1 have contained terminal hydroxamic acid, and none have been successfully advanced due, in part, to safety concerns, including hemodynamic effects. We hypothesized that the safety of LpxC inhibitors could be improved by replacing the terminal hydroxamic acid with a different zinc-binding group. After choosing an N-hydroxyformamide zinc-binding group, we investigated the structure-activity relationship of each part of the inhibitor scaffold with respect to Pseudomonas aeruginosa and Escherichia coli LpxC binding affinity, in vitro antibacterial potency and pharmacological properties. We identified a novel, potency-enhancing hydrophobic binding interaction for an LpxC inhibitor. We demonstrated in vivo efficacy of one compound in a neutropenic mouse E. coli infection model. Another compound was tested in a rat hemodynamic assay and was found to have a hypotensive effect. This result demonstrated that replacing the terminal hydroxamic acid with a different zinc-binding group was insufficient to avoid this previously recognized safety issue with LpxC inhibitors.

2-Pyridineformamide N(4)-ring incorporated thiosemicarbazones inhibit MCF-7 cells by inhibiting JNK pathway.

In an effort to develop a more potent anticancer therapeutic agent, a series of 2-pyridineformamide thiosemicarbazones (R = H, 4-CH3, 5-F, 6-CH3 and ) have been synthesized and evaluated for their anti-cancer activities against the cancer cells MCF-7 (breast cancer cell line), A-431 and A375 (epidermoid carcinoma cell line), and HeLa (cervical cancer cell line) using MTT assay. All these 2-pyridineformamide thiosemicarbazones exhibited anti-proliferative activities towards these cell lines. 5FAmPyrr possess most profound effects against MCF-7 cells with IC50 of 0.9 µM. In flow cytometry using Propidium Iodide, 5FAmPyrr was found to induce cell death significantly in a dose dependent manner (100 nM-3 µM) and inhibited colony formation of MCF-7 cells. This compound induced pro-apoptotic protein Bax and inhibited anti apoptotic protein Bcl-2 as well as both c-Jun and Jun N-terminal kinase (abbreviated as JNK) in concentration dependent manner. Further pro-caspase 3 and PARP were inhibited by 5FAmPyrr at concentration of 3 µM. The results suggest that 5FAmPyrr exhibit anticancer potency and induced cell death by inhibiting MAPK signaling and inducing intrinsic apoptotic pathway. All these indicate that 2-pyridineformamide thiosemicarbazones could be developed as future therapeutics agents to treat cancer.

Discovery of 2-pyridineformamide thiosemicarbazones as potent antiausterity agents.

Series of 2-pyridineformamide thiosemicarbazones were synthesized. Their preferential cytotoxicity in nutrient deprived medium (NDM) was evaluated using PANC-1 human pancreatic cancer cells by employing an antiausterity strategy. 2-Pyridineformamide thiosemicarbazones induced apoptosis and exhibited preferential cytotoxic activity toward PANC-1 cells in NDM, with potencies in the submicromolar range. These compounds are potential candidates for the development of therapeutics against pancreatic cancer.

Effect of gelatinase inhibition on adipogenesis and adipose tissue development.

1. The potential of the matrix metalloproteinase (MMP) inhibitor ABT-518 to affect pre-adipocyte differentiation in vitro and adipose tissue development in vivo was investigated using mouse models of adipogenesis and obesity. 2. Differentiation of 3T3-F442A pre-adipocytes into mature adipocytes was enhanced in a dose-dependent manner by the addition of ABT-518 (0-100 µmol/L). This was associated with increased expression of the adipogenic markers adipocyte fatty acid-binding protein 2 (AP2), peroxisome proliferator-activated receptor γ and adiponectin. 3. Feeding 5-week-old male wild-type mice with a high-fat diet, with or without ABT-518 (to achieve a dose of 100 mg/kg per day), for 16 weeks resulted in a significant reduction in bodyweight throughout the experimental period. Magnetic resonance spectroscopy revealed that the lipid : water ratio was significantly lower in ABT-518-treated mice. The total weight of isolated subcutaneous or gonadal fat depots did not differ significantly following ABT-518 treatment, but adipocyte and blood vessel size were significantly reduced in the gonadal fat. 4. Administration of ABT-518-2 (100 mg/kg per day for 10 weeks) to 5-week-old male wild-type mice with established obesity maintained on a high-fat diet had no effect on total bodyweight at the end of the experiment, but was associated with reduced blood vessel size in the fat depots. 5. Thus, the MMP inhibitor ABT-518 stimulates differentiation of 3T3-F442A pre-adipocytes in vitro. It mildly reduces bodyweight gain in a murine model of diet-induced obesity, but does not affect established obesity.

The inhibitor of 20-HETE synthesis, TS-011, improves cerebral microcirculatory autoregulation impaired by middle cerebral artery occlusion in mice.

BACKGROUND AND PURPOSE: 20-Hydroxyeicosatetraenoic acid is a potent vasoconstrictor that contributes to cerebral ischaemia. An inhibitor of 20-Hydroxyeicosatetraenoic acid synthesis, TS-011, reduces infarct volume and improves neurological deficits in animal stroke models. However, little is known about how TS-011 affects the microvessels in ischaemic brain. Here, we investigated the effect of TS-011 on microvessels after cerebral ischaemia. EXPERIMENTAL APPROACH: TS-011 (0.3 mg·kg(-1) ) or a vehicle was infused intravenously for 1 h every 6 h in a mouse model of stroke, induced by transient occlusion of the middle cerebral artery occlusion following photothrombosis. The cerebral blood flow velocity and the vascular perfusion area of the peri-infarct microvessels were measured using in vivo two-photon imaging. KEY RESULTS: The cerebral blood flow velocities in the peri-infarct microvessels decreased at 1 and 7 h after reperfusion, followed by an increase at 24 h after reperfusion in the vehicle-treated mice. We found that TS-011 significantly inhibited both the decrease and the increase in the blood flow velocities in the peri-infarct microvessels seen in the vehicle-treated mice after reperfusion. In addition, TS-011 significantly inhibited the reduction in the microvascular perfusion area after reperfusion, compared with the vehicle-treated group. Moreover, TS-011 significantly reduced the infarct volume by 40% at 72 h after middle cerebral artery occlusion. CONCLUSIONS AND IMPLICATIONS: These findings demonstrated that infusion of TS-011 improved defects in the autoregulation of peri-infarct microcirculation and reduced the infarct volume. Our results could be relevant to the treatment of cerebral ischaemia.

Effect of 20-HETE inhibition on infarct volume and cerebral blood flow after transient middle cerebral artery occlusion.

This study examined the effects of an inhibitor of 20-hydroxyeicosatetraenoic acid (20-HETE) synthesis, N-(3-chloro-4-morpholin-4-yl)phenyl-N'-hydroxyimido formamide (TS-011), on infarct volume, volume at risk, cerebral blood flow (CBF), and levels of cytochrome P450 (CYP450) eicosanoids in the brain after transient occlusion of the middle cerebral artery (t-MCAO) in rats. TS-011 (0.1 mg/kg, iv) reduced cortical infarct volume by approximately 70% and total infarct volume by 55%. TS-011 had no effect on the volume at risk or CBF during or up to 30 mins after the ischemic period. TS-011 reduced the delayed fall in CBF seen 2 h after reperfusion. The levels of CYP450 eicosanoids were similar in the ischemic and contralateral hemispheres after t-MCAO. TS-011 reduced 20-HETE levels in cerebral tissue by 80% but had no effect on the levels of EETs. Administration of another 20-HETE inhibitor, HET0016 (0.01 to 1.0 mg/kg, iv) or a 20-HETE antagonist 20-hydroxyeicosa-6(Z),15(Z)-dienoic acid (10 mg/kg, iv) also reduced infarct size. These results indicate that inhibitors of the synthesis or vasoconstrictor effects of 20-HETE reduce infarct size in rats after cerebral ischemia. The effects of TS-011 are not associated with changes in the area at risk or CBF and may be because of a potential protective effect in neurons subjected to ischemic stress.

Continuous inhibition of 20-HETE synthesis by TS-011 improves neurological and functional outcomes after transient focal cerebral ischemia in rats.

TS-011, a potent and selective inhibitor of 20-HETE synthesis, has been described as providing significant benefits in animal stroke models. However, no studies have investigated changes in brain 20-HETE levels after cerebral ischemia. Also lacking are studies of TS-011 pharmacodynamics with respect to brain 20-HETE levels that may explain the benefits of TS-011 in animal models of ischemic stroke. The present study sought to explore changes in 20-HETE levels in brain tissue, as well as in plasma, after a 90-min episode of transient focal cerebral ischemia. Pharmacodynamics of TS-011 were also examined. Then, we evaluated the long-term effects of TS-011 when administered as in this pharmacodynamics study. The major findings of the present study are as follows: (1) brain 20-HETE levels increased significantly within 7.5h after MCAO; (2) TS-011 at doses of 0.1 and 0.3mg/kg administered at regular 6-h intervals appeared to reduce brain 20-HETE levels continuously; (3) TS-011 when administered as in this pharmacodynamics study improved long-term neurological and functional outcomes. These findings strongly suggest that 20-HETE plays an important role in the development of neurological and functional deficits after focal cerebral ischemia and that TS-011 may provide benefits in patients suffering ischemic stroke.

A novel method using formamide for the elution of antibodies from erythrocytes.

BACKGROUND AND OBJECTIVES: Accurate identification of antibodies that sensitize red blood cells (RBCs) involves dissociating them from RBCs using an in vitro elution method that does not alter their antigen-binding properties, and analysis of the eluates against a panel of RBCs. MATERIALS AND METHODS: A method was developed that allowed efficient RBC antibody elution. Human polyclonal anti-D was used to sensitize Rh-positive RBCs, and known antigen-antibody disruptive reagents were tested using these RBCs. The best reagent conditions were optimized. Eluates made were tested and compared to results obtained with a glycine-acid-based commercial elution kit to determine efficacy. Patient samples that were positive with direct antiglobulin tests (DATs), and in vitro commercial antisera-sensitized RBCs representing clinically significant antibodies, were used for evaluating the new method. RESULTS: The formamide method was efficient at removing antibodies from RBCs. The patient samples with a positive DAT had antibodies recovered with the same specificity when compared to the acid-based technique. The length of preparation time was similar for both formamide and acid-based methods. Results of testing the eluates made from reagent RBCs sensitized with commercial antisera were distinct with antigen-positive and -negative erythrocytes. CONCLUSIONS: The formamide method compares well with acid techniques and may be an alternative choice of elution method.

N-Methylformamide in advanced squamous cancer of the uterine cervix: an Eastern Cooperative Oncology Group phase II trial.

PURPOSE: Preclinical and clinical data support the study of polar-planar compounds such as N-Methylformamide (NMF) in advanced squamous cell carcinoma of the uterine cervix (SCC). This phase II trial sought to determine the efficacy and toxicities of NMF in patients with advanced SCC. PATIENTS AND METHODS: Eligibility for this trial required bidimensionally measurable squamous or adenosquamous cell cancer of the uterine cervix incurable by surgery or radiation therapy, ECOG performance status of < or = 2, no prior NMF and no more than one prior chemotherapy regimen. Patients received NMF at 2000 mg/m2 intravenously over 15-30 minutes days 1, 8 and 15. The cycle was repeated every 42 days. A single dose escalation of 25%, 500 mg/m2 was made after the first cycle if the toxicities did not exceed grade I for hepatic toxicity and grade II for nausea and vomiting. RESULTS: From July 1987 through September 1998, 21 patients with advanced squamous cell carcinoma of the uterine cervix were entered on study. Two patients were ineligible because there was no pretreatment SGOT on one and the other deteriorated prior to drug approval. Therefore, 19 patients were include in the analysis of response and survival. Four were inevaluable, three due to inappropriate tumor evaluation and one secondary to grade III vomiting, who went off study. These patients were included in the denominator while computing the results. There were 2 deaths, one due to pulmonary hemorrhage from perforation during central venous insertion and one due to disease. 30% (6/19) patients had toxicities, Eastern Cooperative Oncology Group (ECOG) grade III or higher and 2 of these patients suffered multiple grade III toxicities. There were no complete or partial responses. CONCLUSION: In this population, NMF in the dose and schedule employed exhibited no clinical activity.

Effects of sequential combinations of N-methylformamide with adriamycin on cultured melanoma cells (M14).

The effects of sequential combinations of N-methylformamide (NMF) with adriamycin (ADM) on a human melanoma cell line (M14) were investigated. The results obtained can be summarized as follows: (i) When NMF was administered before ADM (NMF-->ADM), a decrease of ADM-induced cytotoxicity and intracellular ADM content was revealed. Conversely, the reverse combination (ADM-->NMF) produced a remarkable reduction of cell survival accompanied by a significant intracellular drug retention. (ii) The fluorescence microscopy revealed that in NMF- and in NMF-->ADM-treated cells the actin microfilament distribution appeared to be very similar to that in control cells. On the contrary, a disorganization of the microfilament architecture was observed in ADM-->NMF-treated cells. (iii) The microtubule organization was significantly altered by NMF. This effect appeared to be even more evident in M14 cells treated with the combination ADM-->NMF. (iv) Confocal microscopy observations showed an intracytoplasmic retention of ADM in ADM-->NMF-treated cells. These findings suggest that the cytoskeletal changes induced by NMF might interfere with the ADM efflux mechanisms, accounting for the high drug level and low survival detected in ADM-->NMF-treated cells.

[The effect of unithiol on the antineoplastic and antimetastatic activity of N-methylformamide]. / Vliianie unitiola na protivoopukholevuiu i antimetastaticheskuiu aktivnost' N-metilformamida.

Antitumor and antimetastatic properties of N-methyl formamide--an agent related to differentiation of tumoral cells and unithiol, official detoxicating drug containing SH-groups were studied in C57Bl/6 mice inoculated with Lewis's lung carcinoma. The drugs were administered intraperitoneally into animals at days 1, 4, 7, 13 and 16 after carcinoma inoculation and their effects were evaluated at day 19. Single administration of unithiol, 5 mg/kg body weight, did not affect tumor growth and metastases spreading. At the same time, N-methyl formamide (single administration of 300 mg/kg body weight) inhibited tumor growth and decreased 5-fold an amount of spontaneous metastases in lungs. However, the antitumor and antimetastatic activities of N-methyl formamide were decreased after simultaneous administration with unithiol. Importance of SH-groups in therapeutic effects of N-methyl formamide is discussed.

Phase II trial of N-methylformamide in patients with metastatic melanoma.

Sixteen patients with metastatic melanoma were treated with N-methylformamide (NMF), a polar-planar compound with in vitro cytotoxic and differentiating properties. Sixteen patients were evaluable for toxicity and 14 for response. The initial four patients received an intravenous bolus of NMF 800 mg/m2 daily for 5 consecutive days every 28 days. Because of excessive gastrointestinal toxicity, the dose was reduced to 700 mg/m2/day for the subsequent 12 patients. Two patients had immediate adverse effects from NMF; one had a grand mal seizure and the other developed severe abdominal pain. Nausea, vomiting and abdominal pain were dose-limiting. Transient elevation of liver function tests occurred in all patients. Myelosuppression was not observed. There were no objective responses among 14 evaluable patients (95% confidence limits 0-20%). One patient with pulmonary metastases had a minor response lasting 13 months. Median time to progression of disease was one month. NMF in these doses and schedule lacks clinical efficacy in the treatment of metastatic melanoma.

Antitumor effect of the new rhodium (II) complex: Rh2 (form)2 (O2 CCF3)2 (H2O)2 (form = N,N'-di-p-tolyl formamidinate).

The new rhodium(II) complex Rh2(Form) (O2CCF3)2(H2O)2 (Form = N,N'-di-p-tolyl formamidinate) was evaluated for its toxicity on the rat and for its efficacy against two tumors of this animal: the Yoshida ascites sarcoma and the T8 sarcoma of Guérin. The rhodium(II) formamidinate shows very low toxicity: in fact 150 mg/kg (the highest quantity of drug soluble in 4 ml of dimenthyl sulfoxide) is not toxic for rats. We were unable to establish the lethal dose or the highest nontoxic dose since larger mounts of complex require a dose of dimethyl sulfoxide (DMSO) that is itself toxic and the compound is insoluble in other solvents such as water or Tween. Doses of rhodium(II) formamidinate, varying from 3 to 30 mg/kg, were administered once by i.p., i.v., i.m. and intratumor (i.t.) route from 1 to 7 days after i.p. injection of 10(6) Yoshida ascites sarcoma cells and subcutaneous (s.c.) implantation of approximately 300 mg (corresponding to 2-3 x 10(7) living tumor cells) of T8 sarcoma of Guérin. The compound is active when administered i.p. 24 hours after Yoshida ascites sarcoma at the smallest dose tested (3 mg/Kg), increasing the average life span of 62.3% and allowing the survival of 50% of the rats. It is also active when administered i.p. at the highest dose tested (30 mg/Kg) 7 days after tumor cell challenge, increasing the average life span in 43.8% and allowing survival in 20% of the rats; it is not active after i.v. or i.m administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Phase II study of N-methylformamide (N-MF) (NSC 3051) in patients with advanced epithelial ovarian cancer. A Gynecologic Oncology Group study.

Forty-four patients with advanced, measurable, epithelial carcinoma of the ovary were treated with 97 courses of N-methylformamide (N-MF) at doses ranging from 600-800 mg/m2, intravenously, daily for 5 days every 28 days. Forty-one patients had prior surgery and had received one prior chemotherapy regimen. Only seven patients had received any prior radiation therapy. All patients were Gynecologic Oncology Group (GOG) performance status 0, 1, or 2. Three partial responses were seen. Hematologic adverse effects were extremely rare as predicted by early clinical trials. One major toxicity was a syndrome consisting of some combination of myalgias, arthralgias, pleuritic pain, abdominal pain, peripheral neuropathy, anorexia, lethargy, and declining performance status (pain-lethargy syndrome) that was reversible with discontinuation of the drug. This adverse effect was as common a reason as hepatic toxicity for discontinuation of N-MF. As reported in previous studies with this drug, hepatic toxicity was also common, usually reversible, and also a cause for discontinuation of the drug. The low level of clinical activity and the unpleasant adverse effects in this population of patients with previously treated ovarian cancer makes it unlikely that this drug will play any significant role in treatment of epithelial ovarian cancer.

Phase II study of N-methylformamide (N-MF) (NSC 3051) in patients with advanced squamous cancer of the cervix. A Gynecologic Oncology Group study.

Twenty patients with advanced measurable, squamous carcinoma of the cervix were treated with 25 courses of N-MF at doses ranging from 600-800 mg/m2, intravenously, daily for 5 days every 28 days. Nineteen patients are evaluable for toxicity and 17 for response. All patients had prior radiation and had received one prior chemotherapy regimen while only 10 patients had had prior surgery. All patients were Gynecologic Oncology Group (GOG) performance status 0, 1, or 2. No responses were seen. Hematologic adverse effects were extremely rare as predicted by early clinical trials. One unusual toxicity was a syndrome consisting of pain, anorexia, lethargy, and declining performance status (pain/lethargy syndrome) that was reversible with discontinuation of the drug. This adverse effect was a reason for discontinuation of N-MF in two patients. As reported in previous studies with this drug, hepatic toxicity was also common, usually reversible, and also a cause for discontinuation of the drug. The lack of clinical activity and the unpleasant adverse effects in this population of patients with previously treated cervix cancer makes it unlikely that this drug will play any significant role in treatment.

Phase II study of n-methylformamide (NSC 3051) and spirogermanium (NSC 192965) in the treatment of advanced small cell lung cancer.

Fifty-four evaluable patients with SCLC previously treated with chemotherapy received either N-methylformamide or spirogermanium. There was one partial response to N-methylformamide. The median survival times for patients treated with N-MF and spirogermanium were 11.7 and 12.6 weeks respectively. Five patients treated with N-MF experienced severe toxicity while four patients treated with spirogermanium experienced severe and life-threatening toxicity.

N-methylformamide affects spontaneous metastases of 3LL lines and increases natural killer activity of tumor-bearing mice.

The antitumor activity of the polar solvent N-methylformamide (NMF) was evaluated on three lines derived from the Lewis lung carcinoma (3LL), endowed with different metastatic potential. Two administration schedules were tested, these being repeated regimens of NMF (200 mg/kg per dose) for 12 consecutive days, starting 24 h or 6-10 days after tumor implantation (early or late treatment, respectively). The results of the present work can be summarized as follows: (1) NMF regimens did not greatly affect tumor growth behavior of 3LL lines; conversely, they markedly influenced their spontaneous colonizing ability in the lungs, either by delaying early metastatic spread or by reducing the number and size of pulmonary metastases already implanted. (2) A significant increase of NK cell activity during and after early treatment with NMF was observed in the more-metastasizing lines, thus suggesting the possibility of an immunomodulating effect of NMF.

Assessment of N-methylformamide (NMF) administered orally on a three times weekly schedule: a phase I study.

This phase I study was conducted to reevaluate the dose-limiting toxicities, maximum tolerated (MTD) and recommended phase II doses of oral NMF administered on a three times weekly schedule for 4 out of every 6 weeks. This schedule was based on the observation that prolonged administration of NMF was associated with the most efficacious antitumor activity in preclinical studies. Phase II trials that employed a starting dose of 800 mg/m2, determined in a previous phase I trial, were suspended because of frequent and severe toxicities. In the current study, a symptom complex characterized by nausea, vomiting, and malaise was the dose-limiting toxicity of oral NMF administered on this schedule. Other toxicities included hepatic enzyme elevations, mild myelosuppression, and worsening of preexistent toxic peripheral neuropathies. Of interest, three patients who were asymptomatic prior to treatment, rapidly developed symptoms of increased intracranial pressure after starting NMF; and, computerized tomographic brain scans revealed metastatic tumors with significant peritumoral edema. NMF was well tolerated at 600 mg/m2, however, an abrupt increase in toxicity resulted when the dose was increased to 700 mg/m2. Although NMF peak plasma concentrations (Cmax) and areas under the plasma disappearance curves (AUC) differed between the 600 and 700 mg/m2 dose levels, these differences were not striking, and similar NMF plasma concentrations and exposures were well tolerated during intravenous trials. Based on this study, the recommended phase II dose for oral NMF administered three times weekly for 4 of 6 weeks was 600 mg/m2.(ABSTRACT TRUNCATED AT 250 WORDS)