2,4-Bis(2-eth-oxy-phen-yl)-7-methyl-3-aza-bicyclo-[3.3.1]nonan-9-one

The crystal structure of the title compound, C(25)H(31)NO(3), exists in a twin-chair conformation with an equatorial orientation of the ortho-eth-oxy-phenyl groups. According to Cremer and Pople [Cremer & Pople (1975 ▶), J. Am. Chem. Soc. 97, 1354-1358], both the piperidone and cyclo-hexa-none rings are significantly puckered with total puckering amplitutdes Q(T) of 0.5889 (18) and 0.554 (2) Å, respectively. The ortho-eth-oxy-phenyl groups are located on either side of the secondary amino group and make a dihedral angle of 12.41 (4)° with respect to each other. The methyl group on the cyclo-hexa-none part occupies an exocyclic equatorial disposition. The crystal packing is stabilized by weak van der Waals inter-actions.

Nuclear Factor κB and Adenosine Receptors: Biochemical and Behavioral Profiling

Adenosine is produced primarily by the metabolism of ATP and mediates its physiological actions by interacting primarily with adenosine receptors (ARs) on the plasma membranes of different cell types in the body. Activation of these G protein-coupled receptors promotes activation of diverse cellular signaling pathways that define their tissue-specific functions. One of the major actions of adenosine is cytoprotection, mediated primarily via two ARs - A(1) (A(1)AR) and A(3) (A(3)AR). These ARs protect cells exposed to oxidative stress and are also regulated by oxidative stress. Stress-mediated regulation of ARs involves two prominent transcription factors - activator protein-1 (AP-1) and nuclear factor (NF)-κB - that mediate the induction of genes important in cell survival. Mice that are genetically deficient in the p50 subunit of NF-κB (i.e., p50 knock-out mice) exhibit altered expression of A(1)AR and A(2A)AR and demonstrate distinct behavioral phenotypes under normal conditions or after drug challenges. These effects suggest an important role for NF-κB in dictating the level of expression of ARs in vivo, in regulating the cellular responses to stress, and in modifying behavior.

Abstract 1184: NADPH oxidase-dependent reactive oxygen species generation regulate micro RNA-21 in prostate cancer

Introduction: MicroRNAs (miRs) are small non-coding RNAs that regulate the coding RNAs at post-transcriptional level. Some miRs have been shown to act as oncomiRs by promoting growth and invasiveness of tumor cells. One of these oncomiRs, miR-21, has been shown to contribute to tumorigenesis of prostate cancer. Although several effector pathways have been suggested for its oncogenic role, little is known about its upstream regulators. In the present study, we hypothesize that high levels of reactive oxygen species (ROS) produced by the NADPH oxidase regulate the expression of miR-21 and its target proteins, maspin and programmed cell death 4 (PDCD4) in prostate cancer cells and prostate cancer samples.

Methods: The levels of miR-21 and NADPH oxidase subunit p47phox were detected in RNA samples from human prostate cancer tissues (from OriGene Technologies) by TaqMan and real time RT-PCR assays, respectively. The levels of maspin and PDCD4 were determined in the formalin-fixed paraffin-embedded (FFPE) prostate tumor sections by immunostaining. In vivo studies were done in severe combined immunodeficient (SCID) mice to study the role of miR-21 and NADPH oxidase in prostate cancer metastasis by injecting transiently-transfected PC3-MM cells with control antisense oligodeoxynucleotides (ODNs), miR-21 antisense ODNs (anti-miR-21), scramble siRNA or p47phox siRNA via the tail vein and counting the metastatic lesions in the lungs. For in vitro studies androgen-independent human prostate cancer cell line PC3-MM was used after transient-transfections with ODNs or siRNAs (as mentioned above). Lysates were used to determine the levels of miR-21 (by TaqMan assay) and maspin, PDCD4 and p47phox (by Western blotting), while invasion and migration was studied by matrigel and wound-healing assays, respectively.

Results: RNA samples from patients with different stages of prostate cancer showed high levels of miR-21 and p47phox. This was associated with low expression of maspin and PDCD4, targets proteins which are negatively regulated by miR-21. Studies in SCID mice showed reduced number of metastatic lung lesions in mice injected with anti-miR-21 and p47phox siRNA- transfected PC3-MM cells in comparison to control ODNs and scramble siRNA-transfected cells. Further studies in PC3-MM cells showed reduced expression of miR-21, maspin and PDCD4, and decreased invasiveness and migration of PC3-MM cells in presence of anti-miR-21 and p47phox siRNA.

Conclusions: Based on the data from the present study we conclude that NADPH oxidase derived ROS serve as essential regulators of miR-21, its target proteins (maspin and PDCD4), and the oncogenic and pro-invasive functions of miR-21 in prostate cancer cells. The increased expression of p47phox could account for the high levels of ROS generation characteristic of prostate cancer cells and aid in promoting high levels of miR-21 expression and oncogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1184. doi:10.1158/1538-7445.AM2011-1184

2,4-Bis(4-propoxyphen-yl)-3-aza-bicyclo-[3.3.1]nonan-9-one

In the title compound, C₂₆H₃₃NO₃, a crystallographic mirror plane bis­ects the mol­ecule (two C atoms, one O atom and one N atom lie on the mirror plane). The mol­ecule exists in a twin-chair conformation with equatorial orientations of the 4-propoxyphenyl groups. The dihedral angle between the 4-propoxyphenyl groups is 31.58 (3)°.

NOX3 NADPH oxidase couples transient receptor potential vanilloid 1 to signal transducer and activator of transcription 1-mediated inflammation and hearing loss

Transient receptor potential vanilloid 1 (TRPV1) is implicated in cisplatin ototoxicity. Activation of this channel by cisplatin increases reactive oxygen species generation, which contribute to loss of outer hair cells in the cochlea. Knockdown of TRPV1 by short interfering RNA protected against cisplatin ototoxicity. In this study, we examined the mechanism underlying TRPV1-mediated ototoxicity using cultured organ of Corti transformed cells (UB/OC-1) and rats. Trans-tympanic injections of capsaicin produced transient hearing loss within 24 h, which recovered by 72 h. In UB/OC-1 cells, capsaicin increased NOX3 NADPH oxidase activity and activation of signal transducer and activator of transcription 1 (STAT1). Intratympanic administration of capsaicin transiently increased STAT1 activity and expression of downstream proinflammatory molecules. Capsaicin produced a transient increase in CD14-positive inflammatory cells into the cochlea, which mimicked the temporal course of STAT1 activation but did not alter the expression of apoptotic genes or damage to outer hair cells. In addition, trans-tympanic administration of STAT1 short interfering RNA protected against capsaicin-induced hearing loss. These data suggest that activation of TRPV1 mediates temporary hearing loss by initiating an inflammatory process in the cochlea via activation of NOX3 and STAT1. Thus, these proteins represent reasonable targets for ameliorating hearing loss.

The design and screening of drugs to prevent acquired sensorineural hearing loss

INTRODUCTION

Sensorineural hearing loss affects a high percentage of the population. Ototoxicity is a serious and pervasive problem in patients treated with cisplatin. Strategies to ameliorate ototoxicity without compromising on antitumor activity of treatments are urgently needed. Similar problems occur with aminoglycoside antibiotic therapy for infections. Noise-induced hearing loss affects a large number of people. The use of ear protection is not always possible or effective. The prevention of hearing loss with drug therapy would have a huge impact in reducing the number of people with hearing loss from these major causes.

AREAS COVERED

This review discusses significant research findings dealing with the use of protective agents against hearing loss caused by cisplatin, aminoglycoside antibiotics and noise trauma. The efficacy in animal studies and the application of these protective agents in clinical trials that are ongoing are presented.

EXPERT OPINION

The reader will gain new insights into current and projected future strategies to prevent sensorineural hearing loss from cisplatin chemotherapy, aminoglycoside antibiotic therapy and noise exposure. The future appears to offer numerous agents to prevent hearing loss caused by cisplatin, aminoglycoside antibiotics and noise. Novel delivery systems will provide ways to guide these protective agents to the desired target areas in the inner ear and circumvent problems with therapeutic interference of antitumor and antibiotics agents as well as minimize undesired side effects.

2,4-Bis(4-but-oxy-phen-yl)-3-aza-bicyclo-[3.3.1]nonan-9-one

In the title compound, C₂₈H₃₇NO₃, a crystallographic mirror plane bis­ects the mol­ecule (one half-mol­ecule in the asymmetric unit). The title compound exists in a twin-chair conformation with an equatorial orientation of the 4-but­oxy­phenyl groups. Both sides of the secondary amino group carry the 4-but­oxy­phenyl groups at an angle of 38.54 (3)° with respect to one another.

3'-Benzoyl-1'-methyl-4'-phenyl-spiro[acenaphthyl-ene-1(2H),2'-pyrrolidin]-2-one

In the title compound, C₂₉H₂₃NO₂, the pyrrolidine ring adopts a twisted conformation about one of the C—N bonds. The acenaphthone ring (r.m.s. deviation = 0.025 Å) lies almost perpendicular to the pyrrolidine ring [dihedral angle = 88.08 (8)°]. The dihedral angle between the phenyl rings is 88.12 (11)°. In the crystal structure, weak C—H⋯π inter­actions connect the mol­ecules.

2,4-Bis(2-methyl-phen-yl)-3-aza-bicyclo[3.3.1]nonan-9-one O-methyl-oxime

The mol­ecule of the title compound, C₂₃H₂₈N₂O, exists in a twin-chair conformation, with equatorial orientation of the ortho-tolyl groups on both sides of the secondary amino group. The title oxime compound and its ketone precursor 2,4-bis­(2-methyl­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one exhibit similar stereochemistries, with the orientation of the o-tolyl rings almost identical in both compounds. In the title compound, the tolyl rings are at an angle of 23.77 (3)° with respect to one another; the angle in the precursor is 29.4 (1)° [Vijayalakshmi, Parthasarathi, Venkatraj & Jeyaraman (2000 ▶), Acta Cryst. C56, 1240–1241]. The cyclo­hexane ring and the oxime ether are disordered over two alternative orientations, with a refined site-occupancy ratio of 0.813 (2):0.186 (4). The crystal structure of the title compound is stabilized by inter­molecular N—H⋯π inter­actions.

Transtympanic administration of short interfering (si)RNA for the NOX3 isoform of NADPH oxidase protects against cisplatin-induced hearing loss in the rat

Cisplatin produces hearing loss in cancer patients. Reactive oxygen species (ROS) in the cochlea leads to lipid peroxidation, death of outer hair cells (OHCs), and hearing loss. The cochlea expresses a unique isoform of NADPH oxidase, NOX3, which serves as the primary source of ROS generation in the cochlea. Inhibition of NOX3 could offer a unique protective target against cisplatin ototoxicity. Here, we document that knockdown of NOX3 using short interfering (si) RNA abrogated cisplatin ototoxicity, as evidenced by protection of OHCs from damage and reduced threshold shifts in auditory brainstem responses (ABRs). Transtympanic NOX3 siRNA reduced the expression of NOX3 in OHCs, spiral ganglion (SG) cells, and stria vascularis (SV) in the rat. NOX3 siRNA also reduced the expression of transient receptor potential vanilloid 1 (TRPV1) channel and kidney injury molecule-1 (KIM-1), biomarkers of cochlear damage. Also, transtympanic NOX3 siRNA reduced the expression of Bax, abolished the decrease in expression of Bcl2, and reduced apoptosis induced by cisplatin in the cochlea. These data suggest that NOX3 regulates stress-related genes in the cochlea, such as TRPV1 and KIM-1, and initiates apoptosis in the cochlea. This appears to be the first study of the efficacy of transtympanic delivery of siRNA attenuating cisplatin ototoxicity.

Lack of association of a spontaneous mutation of the Chrm2 gene with behavioral and physiologic phenotypic differences in inbred mice

The nucleotide substitution C797T in the Chrm2 gene causes substitution of leucine for proline at position 266 (P266L) of the CHRM2 protein. Because Chrm2 codes for the type 2 muscarinic receptor, this mutation could influence physiologic and behavioral phenotypes of mice. Chrm2 mRNA was not differentially expressed in 2 brain regions with high cholinergic innervation in a mouse strain that does (BALB/cByJ) or does not (C57BL/6J) have the mutation. In addition, strains of mice with and without the C797T point mutation in Chrm2 did not differ significantly in muscarinic binding properties. Variation across strains was detected in terms of acoustic startle, prepulse inhibition, and the physiologic effects of the muscarinic agonist oxotremorine. However, interstrain differences in these measures did not correlate with the presence of the mutation. Although we were unable to associate a measurable phenotype with the Chrm2 mutation, assessment of the mutation on other genetic backgrounds or in the context of other traits might reveal differential effects. Therefore, despite our negative findings, evaluation of characteristics that involve muscarinic function should be undertaken with caution when comparing mice with different alleles of the Chrm2 gene.

2-Oxo-4-trifluoromethyl-2H-chromen-7-yl 2-bromo-2-methylpropanoate

In the title compound, C₁₄H₁₀BrF₃O₄, the coumarin ring system is almost plannar (r.m.s. deviation = 0.025 Å) and a short C—H⋯F contact occurs. The propano­ate fragment is orientated almost perpendicular to the ring [dihedral angle = 71.80 (12)°]. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, generating [100] chains.

2-Bromo-2-methyl-N-(4-methyl-2-oxo-2H-chromen-7-yl)propanamide

In the title compound C(14)H(14)BrNO(3), the coumarin ring system is almost planar (r.m.s. deviation = 0.008 Å) and an intra-molecular C-H⋯O inter-action generates an S(6) ring. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, with the C=O unit of the coumarin ring system acting as the acceptor group, generating [010] C(8) chains. The chain connectivity is reinforced by two C-H⋯O inter-actions.

(N1E,N2E)-N1,N2-Bis(4-hexyloxy-3-methoxybenzylidene)ethane-1,2-diamine

The title compound, C₃₀H₄₄N₂O₄, was obtained from the dimerization of 4-hexyl­oxyvanillin with ethyl­enediamine in 95% methanol solution. It adopts a trans configuration with respect to the C=N bond and possesses a crystallographically imposed centre of symmetry.

2,4,6-Trimethyl-3,5-bis[(phenylcarbono-thioyl)sulfanylmethyl]benzyl benzenecarbodithioate

In the title compound C₃₃H₃₀S₆, the three pendant methyl­ene benzodithio­ate groups lie to one side of the central benzene ring in a cis-cis-cis ‘tripod’ arrangement. The dihedral angles between the central benzene ring and the three pendant rings are 72.54 (4), 89.68 (4) and 86.74 (4)°. In the crystal structure, one of the benzene rings is disordered over two orientations in a 0.559 (13):0.441 (13) ratio.

2,4-Bis(4-chloro-phen-yl)-1-methyl-3-aza-bicyclo-[3.3.1]nonan-9-one

The title compound, C₂₁H₂₁Cl₂NO, exists in a twin-chair conformation with an equatorial orientation of the 4-chloro­phenyl groups on both sides of the secondary amino group; the dihedral angle between the 4-chloro­phenyl rings is 36.58 (2)°. The crystal packing is stabilized by an inter­molecular N—H⋯O hydrogen bond and a weak Cl⋯Cl [3.4331 (9) Å] inter­action.

2,4-Bis(2-fluoro-phen-yl)-1-methyl-3-aza-bicyclo-[3.3.1]nonan-9-one

The crystal structure of the title compound, C₂₁H₂₁F₂NO, shows that the compound exists in a twin-chair conformation with an equatorial orientation of the ortho-fluoro­phenyl groups on either side of the secondary amino group. The title compound is a 1-methyl­ated analog of 2,4-bis­(2-fluoro­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one; the two compound both exhibit the same stereochemistry but the orientation of the ortho-fluoro­phenyl rings differs slightly. In the title compound, the rings are orientated at a dihedral angle of 36.70 (3)° with respect to one another, whereas in the non-methyl analog, the angle is 25.68 (4)°. The crystal structure of the title compound is stabilized by an inter­molecular N—H⋯π inter­action and a weak C—H⋯F inter­action.

2,4-Bis(3-methoxy-phen-yl)-3-aza-bicyclo-[3.3.1]nonan-9-one

In the crystal structure, the title compound, C₂₂H₂₅NO₃, exists in a twin-chair conformation with equatorial orientations of the meta-methoxy­phenyl groups on both sides of the secondary amino group. The title compound is a positional isomer of 2,4-bis­(2-methoxy­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one and 2,4-bis­(4-methoxy­phen­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one, which both also exhibit twin-chair conformations with equatorial dispositions of the anisyl rings on both sides of the secondary amino group. In the title compound, the meta-methoxy­phenyl rings are orientated at an angle of 25.02 (3)° with respect to each other, whereas in the ortho and para isomers, the anisyl rings are orientated at dihedral angles of 33.86 (3) and 37.43 (4)°, respectively. The crystal packing is dominated by van der Waals inter­actions and by an inter­molecular N—H⋯O hydrogen bond, whereas in the ortho isomer, an inter­molecular N—H⋯π inter­action (H⋯Cg = 2.75 Å) is found.