Tonic suppression of PCAT29 by the IL-6 signaling pathway in prostate cancer: Reversal by resveratrol

Prostate cancer (PCa) is the second leading cause of cancer deaths in men. A better understanding of the molecular basis of prostate cancer proliferation and metastasis should enable development of more effective treatments. In this study we focused on the lncRNA, prostate cancer associated transcript 29 (PCAT29), a putative tumor suppressive gene. Our data show that the expression of PCAT29 was reduced in prostate cancer tumors compared to paired perinormal prostate tissues. We also observed substantially lower levels of PCAT29 in DU145 and LNCaP cells compared to normal prostate (RWPE-1) cells. IL-6, a cytokine which is elevated in prostate tumors, reduced the expression of PCAT29 in both DU145 and LNCaP cells by activating signal transducer and activator of transcription 3 (STAT3). One downstream target of STAT3 is microRNA (miR)-21, inhibition of which enhanced basal PCAT29 expression. In addition, we show that resveratrol is a potent stimulator of PCAT29 expression under basal condition and reversed the down regulation of this lncRNA by IL-6. Furthermore, we show that knock down of PCAT29 expression by siRNA in DU145 and LNCaP cells increased cell viability while increasing PCAT29 expression with resveratrol decreased cell viability. Immunohistochemistry studies showed increased levels of STAT3 and IL-6, but low levels of programmed cell death protein 4 (PDCD4), in prostate tumor epithelial cells compared to adjacent perinormal prostate epithelial cells. These data show that the IL-6/STAT3/miR-21 pathway mediates tonic suppression of PCAT29 expression and function. Inhibition of this signaling pathway by resveratrol induces PCAT29 expression and tumor suppressor function.

3-Benzylidene-1′-methyl-4′-phenyldispiro[cyclopentane-1,3′-pyrrolidine-2′,1′′-acenaphthene]-2,2′′-dione

In the title compound, C33H27NO2, the pyrrolidine ring adopts an envelope conformation, with the N atom as the flap. The cyclopentanone ring adopts a twisted conformation about the Cs—CH2bond (s = spiro link). The dihedral angle between these rings (all atoms) is 82.02 (15)°. The packing features weak C—H...O interactions.

Adenosine A1 Receptor Protects Against Cisplatin Ototoxicity by Suppressing the NOX3/STAT1 Inflammatory Pathway in the Cochlea

Cisplatin is a commonly used antineoplastic agent that produces ototoxicity that is mediated in part by increasing levels of reactive oxygen species (ROS) via the NOX3 NADPH oxidase pathway in the cochlea. Recent studies implicate ROS generation in mediating inflammatory and apoptotic processes and hearing loss by activating signal transducer and activator of transcription (STAT1). In this study, we show that the adenosine A1 receptor (A1AR) protects against cisplatin ototoxicity by suppressing an inflammatory response initiated by ROS generation via NOX3 NADPH oxidase, leading to inhibition of STAT1. Trans-tympanic administration of the A1AR agonist R-phenylisopropyladenosine (R-PIA) inhibited cisplatin-induced ototoxicity, as measured by auditory brainstem responses and scanning electron microscopy in male Wistar rats. This was associated with reduced NOX3 expression, STAT1 activation, tumor necrosis factor-α (TNF-α) levels, and apoptosis in the cochlea. In vitro studies in UB/OC-1 cells, an organ of Corti immortalized cell line, showed that R-PIA reduced cisplatin-induced phosphorylation of STAT1 Ser(727) (but not Tyr(701)) and STAT1 luciferase activity by suppressing the ERK1/2, p38, and JNK mitogen-activated protein kinase (MAPK) pathways.R-PIA also decreased the expression of STAT1 target genes, such as TNF-α, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and reduced cisplatin-mediated apoptosis. These data suggest that the A1AR provides otoprotection by suppressing NOX3 and inflammation in the cochlea and could serve as an ideal target for otoprotective drug therapy.

SIGNIFICANCE STATEMENT

Cisplatin is a widely used chemotherapeutic agent for the treatment of solid tumors. Its use results in significant and permanent hearing loss, for which no US Food and Drug Administration-approved treatment is currently available. In this study, we targeted the cochlear adenosine A1 receptor (A1AR) by trans-tympanic injections of the agonist R-phenylisopropyladenosine (R-PIA) and showed that it reduced cisplatin-induced inflammation and apoptosis in the rat cochlea and preserved hearing. The mechanism of protection involves suppression of the NOX3 NADPH oxidase enzyme, a major target of cisplatin-induced reactive oxygen species (ROS) generation in the cochlea. ROS initiates an inflammatory and apoptotic cascade in the cochlea by activating STAT1 transcription factor, which is attenuated byR-PIA. Therefore, trans-tympanic delivery of A1AR agonists could effectively treat cisplatin ototoxicity.

Substitution effect on chalcone based materials for corrosion and photocrosslinking applications

Hydroxy (–OH) and benzyloxy (–OCH₂Ph) substituted chalcone based crystalline materials were synthesized and characterized; these materials exhibited high corrosion inhibitor efficiency and enhanced photo-crosslinking applications.

Crystal structure of 2,4-bis-(2-chloro-phen-yl)-7-tert-pent-yl-3-aza-bicyclo[3.3.1]nonan-9-one

The title compound, C₂₅H₂₉Cl₂NO, which is a chloro analog of 2,4-bis­(2-bromo­phen­yl)-7-(tert-pent­yl)-3-aza­bicyclo­[3.3.1]nonan-9-one [Park, Ramkumar & Parthiban (2012). Acta Cryst. E68, o2946], exists in a twin-chair conformation with an equatorial orientation of the 2-chloro­phenyl groups. The tert-pentyl group on the cyclo­hexa­none adopts an exocyclic equatorial position and is disordered between two orientations in a ratio 0.520 (8):0.480 (8). The crystal packing shows no directional contacts beyond van der Waals contacts.

Crystal structure of 2,6-bis-(2,5-di-meth-oxy-phen-yl)-3,5-di-methyl-piperidin-4-one

In the title mol-ecule, C23H29NO5, the central piperidine ring has a chair conformation. The planes of the two benzene rings are inclined each to other at 61.7 (1)°. The crystal packing exhibits no directional inter-actions only van der Waals contacts.

Early investigational drugs for hearing loss

INTRODUCTION

Sensorineural hearing loss (HL) is becoming a global phenomenon at an alarming rate. Nearly 600 million people have been estimated to have significant HL in at least one ear. There are several different causes of sensorineural HL included in this review of new investigational drugs for HL. They are noise-induced, drug-induced, sudden sensorineural HL, presbycusis and HL due to cytomegalovirus infections.

AREAS COVERED

This review presents trends in research for new investigational drugs encompassing a variety of causes of HL. The studies presented here are the latest developments either in the research laboratories or in preclinical, Phase 0, Phase I or Phase II clinical trials for drugs targeting HL.

EXPERT OPINION

While it is important that prophylactic measures are developed, it is extremely crucial that rescue strategies for unexpected or unavoidable cochlear insult be established. To achieve this goal for the development of drugs for HL, innovative strategies and extensive testing are required for progress from the bench to bedside. However, although a great deal of research needs to be done to achieve the ultimate goal of protecting the ear against acquired sensorineural HL, we are likely to see exciting breakthroughs in the near future.

TRPV1: A Potential Drug Target for Treating Various Diseases

Transient receptor potential vanilloid 1 (TRPV1) is an ion channel present on sensory neurons which is activated by heat, protons, capsaicin and a variety of endogenous lipids termed endovanilloids. As such, TRPV1 serves as a multimodal sensor of noxious stimuli which could trigger counteractive measures to avoid pain and injury. Activation of TRPV1 has been linked to chronic inflammatory pain conditions and peripheral neuropathy, as observed in diabetes. Expression of TRPV1 is also observed in non-neuronal sites such as the epithelium of bladder and lungs and in hair cells of the cochlea. At these sites, activation of TRPV1 has been implicated in the pathophysiology of diseases such as cystitis, asthma and hearing loss. Therefore, drugs which could modulate TRPV1 channel activity could be useful for the treatment of conditions ranging from chronic pain to hearing loss. This review describes the roles of TRPV1 in the normal physiology and pathophysiology of selected organs of the body and highlights how drugs targeting this channel could be important clinically.

1'-Allyl-1-(3,4-di-methyl-benzo-yl)-2-(4-methyl-1,3-thia-zol-5-yl)-1,2,5,6,7,7a-hexa-hydro-spiro-[pyrrolizine-3,3'-indolin]-2'-one

In the title compound, C₃₀H₃₁N₃O₂S, the fused pyrrolidine ring bearing three substituents adopts an envelope conformation with the C atom bearing the benzoyl group as the flap. The other fused pyrrolidine ring adopts a twisted conformation about one of its C—C bonds. The dihedral angle between the isatin ring system and the methyl­thia­zole ring is 25.95 (8)°. An intra­molecular C—H⋯O inter­action closes an S(8) ring. In the crystal, mol­ecules are linked by C—H⋯O inter­actions, generating C(11) chains propagating in [001].

Adenosine receptors: expression, function and regulation

Adenosine receptors (ARs) comprise a group of G protein-coupled receptors (GPCR) which mediate the physiological actions of adenosine. To date, four AR subtypes have been cloned and identified in different tissues. These receptors have distinct localization, signal transduction pathways and different means of regulation upon exposure to agonists. This review will describe the biochemical characteristics and signaling cascade associated with each receptor and provide insight into how these receptors are regulated in response to agonists. A key property of some of these receptors is their ability to serve as sensors of cellular oxidative stress, which is transmitted by transcription factors, such as nuclear factor (NF)-κB, to regulate the expression of ARs. Recent observations of oligomerization of these receptors into homo- and heterodimers will be discussed. In addition, the importance of these receptors in the regulation of normal and pathological processes such as sleep, the development of cancers and in protection against hearing loss will be examined.

2-[(E)-2-(4-Methoxyphenyl)ethenyl]-1-methylpyridinium iodide

In the title mol­ecular salt, C₁₆H₁₀NO⁺·I⁻, the dihedral angle between the pyridinium and benzene rings is 6.61 (8)°. In the crystal, the cation is linked to the anion by a C—H⋯I inter­action arising from the activated aromatic C atom adjacent to the N⁺ cation.

Essential role of NADPH oxidase-dependent reactive oxygen species generation in regulating microRNA-21 expression and function in prostate cancer

AIMS

Oncogenic microRNAs (miRs) promote tumor growth and invasiveness. One of these, miR-21, contributes to carcinogenesis in prostate and other cancers. In the present study, we tested the hypothesis that NADPH oxidase-dependent reactive oxygen species (ROS) regulate the expression and function of miR-21 and its target proteins, maspin and programmed cell death 4 (PDCD4), in prostate cancer cells.

RESULTS

The highly aggressive androgen receptor negative PC-3M-MM2 prostate cancer cells demonstrated high expression of miR-21 and p47(phox) (an essential subunit of NADPH oxidase). Using loss-of-function strategy, we showed that transfection of PC-3M-MM2 cells with anti-miR-21- and p47(phox) siRNA (si-p47(phox)) led to reduced expression of miR-21 with concurrent increase in maspin and PDCD4, and decreased the invasiveness of the cells. Tail-vein injections of anti-miR-21- and si-p47(phox)-transfected PC-3M-MM2 cells in severe combined immunodeficient mice reduced lung metastases. Clinical samples from patients with advanced prostate cancer expressed high levels of miR-21 and p47(phox), and low expression of maspin and PDCD4. Finally, ROS activated Akt in these cells, the inhibition of which reduced miR-21 expression.

INNOVATION

The levels of NADPH oxidase-derived ROS are high in prostate cancer cells, which have been shown to be involved in their growth and migration. This study demonstrates that ROS produced by this pathway is essential for the expression and function of an onco-miR, miR-21, in androgen receptor-negative prostate cancer cells.

CONCLUSION

These data demonstrate that miR-21 is an important target of ROS, which contributes to the highly invasive and metastatic phenotype of prostate cancer cells.

Intestinal infestation with Fasciolopsis buski leading to acute kidney injury

Fasciolopsis buski is the largest intestinal fluke infecting human beings. This trematode is endemic in certain parts of the country. Migration poses the risk of spread of the worm to other parts of the country. We report fasciolopsis buski in a migrant from Bihar working in Coimbatore, Tamil Nadu. Acute kidney injury following intestinal obstruction occurred in this case which was never described before.

2,2'-{[(1E,1'E)-(Cyclo-hexane-1,4-diyl)-bis(aza-nylyl-idene)]bis-(ethan-1-yl-1-yl-idene)}diphenol

The title compound, C22H26N2O2, crystallizes with three independent mol-ecules, two of which are situated on inversion centers, so the asymmetric unit contains two independent half-mol-ecules and one mol-ecule in a general position. The two hy-droxy groups in each mol-ecule are involved in intra-molecular O-H⋯N hydrogen bonds, which generate S(6) rings. In the crystal, weak inter-molecular C-H⋯π inter-actions link the mol-ecules into two crystallographically independent columns propagating along [001]; one column consists of mol-ecules in general positions, while the other column is built from alternating independent centrosymmetric mol-ecules.

μ-(2,6-Bis{[3-(di-methyl-amino)-prop-yl]imino-meth-yl}-4-methyl-phenolato)-μ-hydroxido-bis-[(thio-cyanato-κN)copper(II)]

In the title compound, [Cu2(C19H31N4O)(OH)(NCS)2], the mol-ecular structure of the dinuclear complex reveals two penta-coordinated Cu(II) ions, which are bridged by the phenolate O atom of the ligand and by an exogenous hydroxide ion. The bridging atoms occupy equatorial positions in the coordination sphere of the metal atoms and complete the equatorial coordination planes with two ligand N atoms, the apical positions being occupied by thio-cyanate N atoms. The crystal structure also features π-π stacking inter-actions involving the benzene rings with a centroid-centroid distance of 3.764 (4)Å. The crystal studied was a non-merohedral twin, with a refined BASF value of 0.203 (2).

Ethyl 2-amino-4-(4-methyl-1,3-thia-zol-5-yl)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carboxyl-ate

There are two independent mol-ecules in the asymmetric unit of the title compound, C19H16N2O5S, in which the thia-zole rings make dihedral angles of 80.89 (11) and 84.81 (11)° with the pyrano[3,2-c]chromene ring systems. An intra-molecular N-H⋯O hydrogen bond involving the amino group occurs in each independent mol-ecule. In the crystal, the amino groups are involved in N-H⋯O and N-H⋯N hydrogen bonds.

1,3-Bis(2-methyl-prop-2-eno-yl)-1H-benz-imidazol-2(3H)-one

The mol-ecules of the title compound, C15H14N2O3, possesses crystallographically imposed twofold rotational symmetry, so the asymmetric unit contains one half-mol-ecule. The fused-ring system deviates significantly from planarity; the planes of the five- and six-membered rings are twisted with respect to each other by 3.0 (1)°. In the crystal, weak C-H⋯O hydrogen bonds link mol-ecules related by translation in [010] into chains.

Abstract 4084: Resveratrol attenuates prostate cancer growth by inhibiting insulin-like growth factor-1 receptor signaling

Introduction: Prostate cancer is the most commonly diagnosed cancer in the United States. The etiology of prostate cancer development and progression is not very clear. Accumulating evidence suggests that an elevated level of insulin-like growth factor-1 (IGF-1) is positively associated with the growth of prostate cancer. IGF-1 exerts its mitogenic effect by binding to its receptor, IGF-1R, whose expression is also increased during tumor growth. Resveratrol, a phytoalexin, has been shown to possess anti-cancer action against various cancers through unknown mechanism/s. In this study, we examined whether resveratrol mediates its anti-tumor effects by inhibiting the trophic actions of IGF-1/IGF-1R on prostate cancer.

Methods: In vitro studies were performed on highly aggressive androgen receptor negative human prostate cancer cells, PC-3M-MM2. Cell viability was assessed by MTS assays, while apoptosis was determined by Annexin-FITC and PI staining. Additionally, ELISA and western blotting techniques were performed to examine the levels of IGF-1 and protein involved in IGF-axis, respectively. In vivo efficacy of resveratrol was tested in a xenograft model of prostate cancer in severe combined immunodeficient (SCID) mice. PC-3M-MM2 cells were subcutaneously injected in these mice and resveratrol was administered by oral gavage for the assessment of tumor growth. Primary tumors were then excised and immunohistochemistry was performed on the tumor sections. Results: Resveratrol significantly inhibited the release of IGF-1 from PC-3M-MM2 cells and reduced the activation of IGF-1R. Inhibition of IGF-1R by resveratrol suppressed the activation of Akt (pAkt) and increased the expression of programmed cell death 4 (PDCD4), a pro-apoptotic protein and a target of Akt. These effects of resveratrol were associated with reduced cell viability and induction of apoptosis in PC-3M-MM2 cells. Treatment of cells with short interfering (si) RNA against IGF-1R or PI3 kinase inhibitor (LY294002) mimicked the response of resveratrol on cell viability, apoptosis and the expression of pAkt and PDCD4. Furthermore, oral administration of resveratrol in SCID mice that were subcutaneously injected with PC-3M-MM2 cells suppressed subsequent tumor growth. Resveratrol also reduced serum and tumor levels of IGF-1 and inhibited the activation of IGF-1R in these tumors. This modulation of IGF-1/IGF-1R coincided with the inhibition of pAkt and increase in PDCD4 in the tumor tissue.

Conclusion: Our results indicate that resveratrol effectively suppressed prostate cancer growth in vitro as well as in vivo by attenuating IGF-1/IGF-1R signaling pathway. These data demonstrate that the IGF/IGF-1R represent a relevant target of resveratrol for mediating its anti-tumor actions against prostate cancer.

Citation Format: Sandeep Sheth, Sarvesh Jajoo, Debashree Mukherjea, Kelly Sheehan, Leonard P. Rybak, Vickram Ramkumar. Resveratrol attenuates prostate cancer growth by inhibiting insulin-like growth factor-1 receptor signaling. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4084. doi:10.1158/1538-7445.AM2013-4084