[circDDX17 targets miR-223-3p / RIP3 to regulate the proliferation and apoptosis of non-small cell lung cancer cells]

Objective: To explore the molecular mechanism of circDDX17 regulating the proliferation and apoptosis of non-small cell lung cancer cells by targeting the miR-223-3p/RIP3 molecular axis. Methods: The expression levels of circDDX17, miR-223-3p, and RIP3 in human normal lung epithelial cell lines BEAS-2B and non-small cell lung cancer cells H1299, A549, and H446 were detected by reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR). The plasmids of pcDNA, pcDNA-circDDX17, anti-miR-con, anti-miR-223-3p, pcDNA-circDDX17 and miR-con, pcDNA-circDDX17 and miR-223-3p mimics were transfected into H1299 cells. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) assay was used to detect the cell proliferation. Flow cytometry was used to detect the cell cycle and cell apoptosis. Plate cloning experiment was used to detect cell proliferation ability. The dual luciferase report experiment was applied to verify the targeting relationship between miR-223-3p with circDDX17 and RIP3. Western blot was used to detect the protein expression of cyclinD1, CDK2, cleaved caspase-3 and Bax. Results: The expression levels of circDDX17 and RIP3 mRNA in H1299, A549, and H446 cells were significantly reduced (P<0.05), the expression level of miR-223-3p mRNA was significantly increased (P<0.05) compared with BEAS-2B. The cell viability [(69.46±4.68)%], the number of cell clones (83.49±7.86), the proportion of cells in S phase [(22.52±1.41) %], the protein expression levels of cyclinD1 and CDK2 in PCDNa-CircDDX17 group were lower than those in pcDNA group [(97.54±7.72)%, 205.03±13.37, (28.69±1.49)%, respectively, P<0.05], while the percentage of G0/G1 phase cells [(64.45±3.56)%], apoptosis rate [(18.36±1.63)%], the protein expression levels of cleaved caspase-3 and Bax in pcDNA-circDDX17 group were higher than those of pcDNA group [(51.33±2.76) % and (5.21±0.54) %, respectively, P<0.05]. The viability [(72.64±5.44)%], the number of cell clones (78.16±8.23), the proportion of S-stage cells [(21.34±1.59) %], the protein expression levels of CyclinD1 and CDK2 in anti-miR-223-3p group were lower than those in anti-miR-con group [(103.47±6.25)%, 169.32±14.53, (28.43±1.26)%, respectively, P<0.05]. Percentage of G0/G1 phase cells [(62.86±3.28)%], apoptosis rate [(14.64±1.67)%], the protein expression levels of cleaved caspase-3 and Bax in the anti-miR-223-3p group were higher than those of anti-miR-con group [(51.33±2.71)% and (4.83±0.39)%, respectively, P<0.05]. MiR-223-3p has complementary sites with circDDX17 or RIP3. The viability [(135.45±9.28)%], the number of cell clones (174.64±10.68), the proportion of S-phase cells [(26.39±2.25)%], the protein expression levels of cyclinD1 and CDK2 in pcDNA-circDDX17+miR-223-3p group were higher than those in pcDNA-circDDX17+miR-con group [(101.56±6.68)%, 107.65±7.62, (21.64±1.72)%, P<0.05]. Percentage of G0/G1 phase cells [(56.64±2.76)%], apoptosis rate [(8.34±0.76)%], the protein expression levels of cleaved caspase-3 and Bax in pcDNA-circDDX17+miR-223-3p group were lower than those of pcDNA-circDDX17+miR-con group [(64.03±3.48)% and (15.21±1.18)%, respectively, P<0.05]. Conclusion: circDDX17 could inhibit the proliferation and induce apoptosis of non-small cell lung cancer cells via targeting the miR-223-3p / RIP3 molecular axis.

Discovery of (R)-7-cyano-2,3,4, 5-tetrahydro-1-(1H-imidazol-4-ylmethyl)-3- (phenylmethyl)-4-(2-thienylsulfonyl)-1H-1,4-benzodiazepine (BMS-214662), a farnesyltransferase inhibitor with potent preclinical antitumor activity

Continuing structure-activity studies were performed on the 2,3,4, 5-tetrahydro-1-(imidazol-4-ylalkyl)-1,4-benzodiazepine farnesyltransferase (FT) inhibitors. These studies demonstrated that a 3(R)-phenylmethyl group, a hydrophilic 7-cyano group, and a 4-sulfonyl group bearing a variety of substituents provide low-nanomolar FT inhibitors with cellular activity at concentrations below 100 nM. Maximal in vivo activity in the mutated K-Ras bearing HCT-116 human colon tumor model was achieved with analogues carrying hydrophobic side chains such as propyl, phenyl, or thienyl attached to the N-4 sulfonyl group. Several such compounds achieved curative efficacy when given orally in this model. On the basis of its excellent preclinical antitumor activity and promising pharmacokinetics, compound 20 (BMS-214662, (R)-7-cyano-2,3,4, 5-tetrahydro-1-(1H-imidazol-4-ylmethyl)-3-(phenylmethyl)-4-(2-thie nyl sulfonyl)-1H-1,4-benzodiazepine) has been advanced into human clinical trials.

3-Imidazolylmethylaminophenylsulfonyltetrahydroquinolines, a novel series of farnesyltransferase inhibitors

Design, synthesis and structure-activity relationship of a series of 3-imidazolylmethylaminophenylsulfonyltetrahydroquinolines as farnesyltransferase inhibitors are presented. A working pharmacophore of inhibiting farnesyltransferase by this series of inhibitors is proposed.

Discovery and structure-activity relationships of imidazole-containing tetrahydrobenzodiazepine inhibitors of farnesyltransferase

2,3,4,5-Tetrahydro-1-(imidazol-4-ylalkyl)-1,4-benzodiazepines were found to be potent inhibitors of farnesyltransferase (FT). A hydrophobic substituent at the 4-position of the benzodiazepine, linked via a hydrogen bond acceptor, was important to enzyme inhibitory activity. An aryl ring at position 7 or a hydrophobic group linked to the 8-position through an amide, carbamate, or urea linkage was also important for potent inhibition. 2,3,4, 5-Tetrahydro-1-(1H-imidazol-4-ylmethyl)-7-(4-pyridinyl)-4-[2-(t rifluo romethoxy)benzoyl]-1H-1,4-benzodiazepine (36), with an FT IC(50) value of 24 nM, produced 85% phenotypic reversion of Ras transformed NIH 3T3 cells at 1.25 microM and had an EC(50) of 160 nM for inhibition of anchorage-independent growth in soft agar of H-Ras transformed Rat-1 cells. Selected analogues demonstrated ip antitumor activity against an ip Rat-1 tumor in mice.

Cardioselective antiischemic ATP-sensitive potassium channel (K(ATP)) openers. 6. Effect of modifications at C6 of benzopyranyl cyanoguanidines

The effect on potency and selectivity of modifications at the C6 position of the cardioprotective K(ATP) opener BMS-180448 (2) is described. Structure-activity studies show that a variety of electron-withdrawing groups (ketone, sulfone, sulfonamide, etc.) are tolerated for cardioprotective activity as measured by EC(25) values for an increase in time to the onset of contracture in globally ischemic rat hearts. Changes made to the sulfonamido substituent indicate that compounds derived from secondary lipophilic amines are preferred for good cardioprotective potency and selectivity. The diisobutyl analogue 27 (EC(25) = 0.04 microM) is the most potent compound of this series. The cardiac selectivity of 27 results from a combination of reduced vasorelaxant potency and enhanced cardioprotective potency relative to the potent vasodilating K(ATP) openers (e.g., cromakalim). The diisobutylsulfonamide analogue 27 is over 4 orders of magnitude more cardiac selective than cromakalim (1). These results support the hypothesis that the cardioprotective and vasorelaxant properties of K(ATP) openers follow distinct structure-activity relationships. The mechanism of action of 27 appears to involve opening of the cardiac K(ATP) as its cardioprotective effects are abolished by the K(ATP) blocker glyburide.

Inactivation of monoamine oxidase B by benzyl 1-(aminomethyl) cyclopropane-1-carboxylate

Monoamine oxidase (MAO) is a flavoenzyme that catalyzes the oxidation of various biogenic and xenobiotic amines. Benzyl 1-(aminomethyl)cyclopropane-1-carboxylate (1) was designed as a diactivated cyclopropane mechanism-based inactivator of MAO (Silverman, R.B.: Ding, C.Z.; Borrillo, J.L.; Chang, J.T.J. Am. Chem. Soc. 1993, 115, 2982). [1,1-2H2]-1 exhibits a deuterium isotope effect of 4.5 on inactivation, but in D2O the isotope effect is only 2.3. [1-3H]-1 and [1-14C]-1 were synthesized; upon inactivation of MAO, 1.1 and 2.0 equiv of radioactivity, respectively, are incorporated into the enzyme. Tritium as 3H2O, is released during inactivation with [1-3H]-1. The flavin absorption spectrum changes from that of oxidized to that of reduced flavin after inactivation; denaturation of the inactivated enzyme shows a reduced flavin spectrum, suggesting the formation of a modified flavin. Tryptic digestion of the enzyme labeled with [1-3H]-1 or [1-14C]-1, followed by HPLC analysis, monitoring at 310 nm [corrected] (flavin), shows that the radioactivity comigrates with the 310 nm [corrected] absorptions. The metabolites that are generated during inactivation are benzyl 1-formylcyclopropane-1-carboxylate, benzyl alcohol, and 1-formylcyclopropane-1-carboxylic acid; no ring-cleaved products were detected. The partition ratio, as determined from the ratio of nonamines to enzyme, is 110. These results are rationalized in terms of a single-electron transfer mechanism leading to the imine of benzyl 1-formylcyclopropane-1-carboxylate, which alkylates the flavin coenzyme.

Cardioselective antiischemic ATP-sensitive potassium channel (KATP) openers. 5. Identification of 4-(N-aryl)-substituted benzopyran derivatives with high selectivity

This paper describes our studies aimed at the discovery of structurally distinct analogs of the cardioprotective KATP opener BMS-180448 (2) with improved selectivity for the ischemic myocardium. The starting compound 6, derived from the indole analog 4. showed good cardioprotective potency and excellent selectivity compared to 2 and the first-generation KATP opener cromakalim (1). The structure-activity studies indicate that increasing the size of the alkyl ester leads to diminished potency as does its replacement with a variety of other groups (nitrile, methyl sulfone). Replacement of the ethyl ester of 6 with an imidazole gave the best compound 3 (BMS-191095) of this series which maintains the potency and selectivity of its predecessor 6. The results described in this publication further support that there is no correlation between vasorelaxant and cardioprotective potencies of KATP openers. Compound 3 is over 20- and 4000-fold more selective for the ischemic myocardium than 2 and cromakalim (1), respectively. The selectivity for the ischemic myocardium is achieved by reduction of vasorelaxant potency rather than enhancement in antiischemic potency. As for cromakalim (1) and 2, the cardioprotective effects of compound 3 are inhibited by cotreatment with the KATP blocker glyburide, indicating that the KATP opening is involved in its mechanism of cardioprotection. With its good oral bioavailability (47%) and plasma elimination half-life (3 h) in rats, compound 3 offers an excellent candidate to investigate the role of residual vasorelaxant potency of 2 toward its cardioprotective activity in vivo.

Cardioselective antiischemic ATP-sensitive potassium channel openers. 4. Structure-activity studies on benzopyranylcyanoguanidines: replacement of the benzopyran portion

The results of our efforts aimed at the replacement of the benzopyran ring of the lead cardiac selective antiischemic ATP-sensitive potassium channel (KATP) opener (4) are described. Systematic modification of the benzopyran ring of 4 resulted in the discovery of a structurally simpler acyclic analog (8) with slightly lower antiischemic potency than the lead compound 4. Further structure-activity studies on the acyclic analog 8 provided the 2-phenoxy-3-pyridylurea analog 18 with improved antiischemic potency and selectivity compared to the benzopyran-based compound 4. These data demonstrate that the benzopyran ring of 4 and its congeners is not mandatory for antiischemic activity and cardiac selectivity. The results described in this paper also show that, as for the benzopyran class of compounds, the structure-activity relationships for the antiischemic and vasorelaxant activities of KATP openers are distinct. The mechanism of action of the acyclic analogs (e.g., 18) still appears to involve KATP opening as their cardioprotective effects are abolished by pretreatment with the KATP blocker glyburide.

Transformation of heterocyclic reversible monoamine oxidase-B inactivators into irreversible inactivators by N-methylation

3-[4-[(3-Chlorophenyl)methoxy]phenyl]-5-[(methylamino)methyl]- 2-oxazolidinone (1) is a secondary amine known to be a potent time-dependent irreversible inactivator of monoamine oxidase B (MAO-B). The primary amine analogues of derivatives of 1, as well as of the corresponding dihydrofuranone and pyrrolidinone, had been shown to be time-dependent, but reversible, inhibitors of MAO-B. Here it is shown that the primary amine analogue of 1 is a time-dependent reversible inhibitor of MAO-B and that the secondary and tertiary amine analogues of the corresponding oxazolidinone, dihydrofuranone, and pyrrolidinone are time-dependent irreversible inhibitors of MAO-B. The reaction leading to the irreversible enzyme adduct formation with 1 can be reversed by increasing the temperature. These results are consistent with a stabilizing stereoelectronic effect on the enzyme adduct caused by N-methylation which hinders free rotation and prevents the sp3-orbital containing the nitrogen nonbonded electrons from being trans to the active site amino acid leaving group.

Transformation of monoamine oxidase-B primary amine substrates into time-dependent inhibitors. Tertiary amine homologues of primary amine substrates

A family of N-methylated and N,N-dimethylated alkyl and arylalkylamines was prepared and more than half of the analogues were shown to be time-dependent pseudo-first-order inhibitors of monoamine oxidase-B. Some of the time-dependent inactivators were reversible and others were irreversible with respect to prolonged dialysis following inactivation. Partition ratios ranged from zero to 11,000. These results are rationalized in terms of a combination of an inductive effect and a stereoelectronic effect as a result of hindered rotation of an active site covalent adduct. A molecular mechanics calculation indicates that there is at least 10 kcal/mol of torsional energy to be overcome in order for the enzyme adduct to be released. These findings show that tertiary amine homologues of primary amine substrates of monoamine oxidase are time-dependent inhibitors, and this should be useful in the design of new inactivators of this enzyme.

4-(Aminomethyl)-1-aryl-2-pyrrolidinones, a new class of monoamine oxidase B inactivators

Both 4-(aminomethyl)-1-phenyl-2-pyrrolidinone (4a) and 4-(aminomethyl)-1- (methoxyphenyl)-2-pyrrolidinone (4b) hydrochlorides were synthesized via a six-step sequence, which represents a general approach to 1,4-disubstituted 2-pyrrolidinones. Both of these compounds inactivated monoamine oxidase B and represent the first in a new class of monomamine oxidase inactivators.