Radiolabeled ligand binding to the catalytic or allosteric sites of
O76074
REA
and PDE 11 . Cyclic nucleotide phosphodiesterases ( PDEs ) have been investigated for years as targets for therapeutic intervention in a number of pathophysiological processes . Phosphodiesterase - 5 (
O76074
REA
) , which is highly specific for guanosine 3 ' - 5 ' - cyclic-monophosphate ( cGMP ) at both its catalytic site and its allosteric sites , has generated particular interest because it is potently and specifically inhibited by three drugs : sildenafil ( Viagra , Pfizer ) , tadalafil ( DB00820 , Lilly -
Q9Y6W8
REA
) , and vardenafil (
DB00862
MEN
, Bayer GSK ) . Previously , we have used [ ( 3 ) H ] cGMP to directly study the interaction of cGMP with the allosteric sites of
O76074
REA
, but because cGMP binds with relatively low affinity to the catalytic site , it has been difficult to devise a binding assay for this particular binding reaction . This approach using measurement of radiolabeled ligand binding continues to allow us to more precisely define functional features of the enzyme . We now use a similar approach to study the characteristics of high-affinity [ ( 3 ) H ] inhibitor binding to the
O76074
REA
catalytic domain . For these studies , we have prepared [ ( 3 ) H ] sildenafil and [ ( 3 ) H ] tadalafil , two structurally different competitive inhibitors of
O76074
REA
. The results demonstrate that radiolabeled ligands can be used as probes for both catalytic site and allosteric site functions of
O76074
REA
. We describe herein the methods that we have established for studying the binding of radiolabeled ligands to both types of sites on
O76074
REA
. These techniques have also been successfully applied to the study of binding of radiolabeled
O76074
REA
inhibitors to PDE 11 , suggesting that these methods are applicable to the study of other PDEs , and perhaps other enzyme families .
1
Persistent Cdk 2 inactivation drives growth arrest of
P11274
REA
-
P00519
REA
- expressing cells in response to dual inhibitor of
P12931
REA
and
P00519
REA
kinases SKI 606 . Complementary inhibition of tyrosine and
P12931
REA
kinases implement dual
P12931
REA
/
P00519
REA
inhibitor effects in chronic myeloid leukemia ( CML ) . Here , we show that one such inhibitor ,
DB06616
MEN
, induces persistent Cdk 2 inactivation leading to growth arrest of
P11274
REA
-
P00519
REA
- expressing cells either IM-sensitive or driven to IM-resistance by other events than gene overexpression and point mutations . Inhibition of Akt serine / threonine kinase , a phosphatidylinositol 3 kinase ( PI - 3k ) target that integrates
Q92817
REA
TK signaling with membrane-associated
P12931
REA
kinases , is a central component of restored expression and subcellular redistribution of Cdk 2 regulatory signals (
P38936
REA
and p27 and Cdc 25A phosphatase ) in response to
DB06616
MEN
. The putative roles of growth factor ( namely
P08700
REA
) autocrine loop in
P11274
REA
-
P00519
REA
- expressing progenitor progression towards a drug-resistant phenotype are discussed .
2
Suppression of androgen receptor-mediated gene expression by a sequence-specific DNA-binding polyamide .
P10275
REA
( AR ) is essential for the growth and progression of prostate cancer in both hormone-sensitive and hormone-refractory disease . A DNA-binding polyamide that targets the consensus androgen response element binds the prostate-specific antigen ( PSA ) promoter androgen response element , inhibits androgen-induced expression of PSA and several other AR-regulated genes in cultured prostate cancer cells , and reduces AR occupancy at the PSA promoter and enhancer . Down-regulation of PSA by this polyamide was comparable to that produced by the synthetic antiandrogen bicalutamide (
DB01128
SUB
) at the same concentration . Genome-wide expression analysis reveals that a similar number of transcripts are affected by treatment with the polyamide and with bicalutamide . Direct inhibition of the AR-DNA interface by sequence-specific DNA binding small molecules could offer an alternative approach to antagonizing AR activity .
3
P09917
REA
- activating protein inhibitors : development of 3 - [ 3 - tert-butylsulfanyl - 1 - [ 4 - ( 6 - methoxy-pyridin - 3 - yl ) - benzyl ] - 5 - ( pyridin - 2 - ylmethoxy ) - 1H - indol - 2 - yl ] -2,2- dimethyl-propionic acid (
DB05225
MEN
) . The potent and selective
P09917
REA
- activating protein leukotriene synthesis inhibitor 3 - [ 3 - tert-butylsulfanyl - 1 - [ 4 - ( 6 - methoxy-pyridin - 3 - yl ) - benzyl ] - 5 - ( pyridin - 2 - ylmethoxy ) - 1H - indol - 2 - yl ] -2,2- dimethyl-propionic acid ( 11j ) is described . Lead optimization was designed to afford compounds with superior in vitro and in vivo inhibition of leukotriene synthesis in addition to having excellent pharmacokinetics and safety in rats and dogs . The key structural features of these new compounds are incorporation of heterocycles on the indole N-benzyl substituent and replacement of the quinoline group resulting in compounds with excellent in vitro and in vivo activities , superior pharmacokinetics , and improved physical properties . The methoxypyridine derivative 11j has an IC ( 50 ) of 4.2 nM in a
P09917
REA
- activating protein (
P20292
REA
) binding assay , an IC ( 50 ) of 349 nM in the human blood
Q06643
REA
( 4 ) inhibition assay , and is efficacious in a murine ovalbumin model of allergen-induced asthma . Compound 11j was selected for clinical development and has successfully completed phase 1 trials in healthy volunteers .
4
Prolonged treatment with bicalutamide induces androgen receptor overexpression and androgen hypersensitivity . BACKGROUND : Various hormone refractory prostate cancer cell models have been established with androgen depletion and have helped to clarify the mechanism for the transition into androgen-depletion independent status . However , the mechanism of bicalutamide resistance remains unclear because few cell models have been generated . METHODS : We generated a bicalutamide-resistant subline , LNCaP -
O43633
REA
, from LNCaP after prolonged treatment with bicalutamide . Androgen and / or bicalutamide responsiveness for proliferation and prostate-specific antigen ( PSA ) secretion were examined in vitro and in vivo . DB00624 and dihydrotestosterone ( DB02901 ) levels in xenografted tumors were analyzed by liquid chromatography-tandem mass spectrometry .
P10275
REA
( AR ) gene mutation and amplification and AR and pAR ( 210 ) expression were determined . RESULTS : LNCaP -
O43633
REA
did not grow in an androgen-depleted medium and proliferation was stimulated in a tenfold lower concentration of androgen than that of LNCaP . LNCaP -
O43633
REA
grew in castrated male mice , and the DB02901 level in grafted LNCaP -
O43633
REA
tumors was 7.7- fold lower than in LNCaP tumors .
DB01128
SUB
stimulated LNCaP -
O43633
REA
proliferation and PSA secretion in vitro and the antitumor activity of bicalutamide against LNCaP -
O43633
REA
was weaker than that of LNCaP in vivo . Additional AR mutation and AR gene amplification were not detected in LNCaP -
O43633
REA
, but AR and pAR ( 210 ) expression and PSA secretion in LNCaP -
O43633
REA
were higher than in LNCaP . CONCLUSIONS :
DB01128
SUB
- resistant LNCaP -
O43633
REA
exhibited AR overexpression and hypersensitivity to low levels of androgen . Our data suggests that AR overexpression is a significant mechanism of bicalutamide resistance similar to resistance from chronic androgen depletion . In addition , pAR ( 210 ) overexpression could be a potential mechanism for hypersensitivity to low androgen in LNCaP -
O43633
REA
.
5
Immunohistochemical analysis of carcinomatous and sarcomatous components in the uterine carcinosarcoma : a case report . Uterine carcinosarcoma ( malignant mixed Mullerian tumor ) is an uncommon female genital tract neoplasm characterized by an admixture of epithelial and stromal malignant cells . We report a case of 50 - year-old peri-menopausal woman diagnosed to have early-stage ( IB due to FIGO ) uterine carcinosarcoma of the homologous type with superficial ( 3mm ) myo-invasion . The patient showed no clinical symptoms of the disease and had no family history of female genital tract malignancies . Positive immunostaining for steroid receptors ( estrogen-alpha and progesterone receptors ) , cytokeratin , and
P00533
REA
was detected only in the carcinomatous area , whereas beta-catenin , BCL - 2 ,
P35354
REA
, p16 ( INK 4a ) ,
P60484
REA
, Q8IUH3 , and vimentin were immunoreactive in both components .
P10275
REA
, CD10 , desmin , HER - 2 / neu , and
P04637
REA
were found to be negative either in the carcinomatous or in the sarcomatous area . Tumor proliferative activity was higher in the carcinomatous ( 25 % ) than in the sarcomatous ( 2 % ) component . Based on these findings , immunohistochemical evaluation of multiple receptor status in the carcinomatous and sarcomatous areas of carcinosarcoma may provide a clue to the pathogenesis and hormonal receptor status of this uncommon uterine malignancy .
6
P10275
REA
YAC transgenic mice recapitulate SBMA motor neuronopathy and implicate VEGF 164 in the motor neuron degeneration . X-linked spinal and bulbar muscular atrophy ( SBMA ) is an inherited neuromuscular disorder characterized by lower motor neuron degeneration . SBMA is caused by polyglutamine repeat expansions in the androgen receptor ( AR ) . To determine the basis of AR polyglutamine neurotoxicity , we introduced human AR yeast artificial chromosomes carrying either 20 or 100 CAGs into mouse embryonic stem cells . The AR100 transgenic mice developed a late-onset , gradually progressive neuromuscular phenotype accompanied by motor neuron degeneration , indicating striking recapitulation of the human disease . We then tested the hypothesis that polyglutamine-expanded AR interferes with CREB binding protein ( CBP ) - mediated transcription of vascular endothelial growth factor (
P15692
REA
) and observed altered CBP-AR binding and
P15692
REA
reduction in AR100 mice . We found that mutant AR-induced death of motor neuron-like cells could be rescued by
P15692
REA
. Our results suggest that SBMA motor neuronopathy involves altered expression of
P15692
REA
, consistent with a role for
P15692
REA
as a neurotrophic / survival factor in motor neuron disease .
7
5 - Azacitidine restores and amplifies the bicalutamide response on preclinical models of androgen receptor expressing or deficient prostate tumors . BACKGROUND : Epigenetic modifications play a key role in the in prostate cancer ( Pca ) progression to a hormone refractory state ( HRPC ) and the current use of agents targeting epigenetic changes has become a topic of intense interest in cancer research . In this regard , 5 - Azacitine ( 5 - Aza ) represents a promising epigenetic modulator . This study tested the hypothesis that 5 - Aza may restore and enhance the responsiveness of HRPC cells to anti-hormonal therapy on
P10275
REA
( AR ) expressing ( 22rv1 ) and AR-deficient ( PC3 ) cells . METHODS : The effects were studied in vitro and in vivo models . This sequential treatment induced in vitro cell cycle arrest and apoptosis both in 22rv1 and PC3 tumor cell lines . RESULTS : This combined treatment up-regulated the expression of
P48023
REA
, phospho -
Q13158
REA
, p16 ( INKA ) , Bax , Bak , and
P38936
REA
(
P38936
REA
) , and inhibited FLIP , Bcl - 2 , and Bcl-XL expression . The re-activation of hormonal response of AR-negative PC3 cell line was partially due to the AR re-expression mediated by 5 - Aza treatment . In contrast , the increase in the response to anti-androgenic therapy in 22rv1 did not correlate with AR expression levels . Furthermore , xenograft studies revealed that the combined treatment of 5 - Aza with AR-antagonist
DB01128
SUB
had additive / synergistic effects in repressing tumor growth in vivo and the underlying mechanisms responsible for these effects seem to be in part mediated by induction of apoptosis . CONCLUSIONS : So , this study strongly suggests a therapeutic potential of 5 - Aza in combination with anti-androgen therapy in patients with in AR expressing and AR-deficient HRPC .
8
Q9NZQ7 expression on non-B and non-T cells promotes distinct effects on T - and B-cell responses in autoimmune arthritis . The immune system has developed several regulatory mechanisms to maintain homeostasis of adaptive immune responses . T-cell programmed death ( PD ) - 1 recognition of Q9NZQ7 ( Q9NZQ7 ) expressed on
P25054
REA
and non-lymphoid tissue regulates T-cell activation . We show that Q9NZQ7 ( - / - ) mice exhibit exacerbated proteoglycan ( PG ) - induced arthritis and increased Th - 1
P01730
REA
( + ) T-cell responses . Unexpectedly , the PG-specific antibody response in Q9NZQ7 ( - / - ) mice was diminished . A reduction in the number of peanut agglutinin ( + ) GC coincided with a decrease in
P15391
REA
( + ) GL - 7 ( + ) CD95 ( + ) GC B cells that was a result of increased caspase-induced apoptosis . The percent of
P28907
REA
( + ) CD138 ( + ) emerging plasma cells was decreased . Q9NZQ7 ( - / - ) mice exhibited an increased frequency of
P01730
REA
( + )
P18621
REA
( hi )
P32302
REA
( hi )
Q9Y6W8
REA
( hi ) CD62L ( lo ) T follicular helper cells that displayed a hyperactive phenotype with increased expression of mRNA transcripts for Bcl 6 , Q9HBE4 , and the apoptosis-inducer molecule
P48023
REA
. In cell transfer of Q9NZQ7 ( - / - ) cells into SCID mice , non-B and non-T cells were sufficient to normalize the antibody response , T-cell hyperactivity , and the development of PG-induced arthritis . These findings indicate that Q9NZQ7 on non-B and non-T cells signals through
P18621
REA
on T effector cells to prevent excessive activation and reduce autoimmune arthritis . Furthermore , these findings demonstrate a novel role for Q9NZQ7 expression in promoting B-cell survival by regulating the activation of T follicular helper cell .
9
Effects of zileuton and montelukast in mouse experimental spinal cord injury . BACKGROUND AND PURPOSE :
P09917
REA
(
P09917
REA
) is the key enzyme in leukotriene ( LT ) biosynthesis from arachidonic acid ( AA ) . Here , we examined the role of the
P09917
REA
- product , cysteinyl-LT ( DB00151 - LT ) , with a
P09917
REA
inhibitor ( zileuton ) and a DB00151 - LT , receptor antagonist ( montelukast ) , in the inflammatory response and tissue injury associated with spinal cord injury ( SCI ) . EXPERIMENTAL APPROACH : SCI was induced in mice by the application of vascular clips to the dura via a two-level Q8NHM4 to T7 laminectomy for 1 min . Cord inflammation was assessed histologically and by measuring inflammatory mediators ( ELISA ) and apoptosis by annexin V , TUNEL ,
P48023
REA
staining and Bax and Bcl - 2 expression ( immunohistochemistry and western blots ) . Motor function in hindlimbs was assessed by a locomotor rating scale , for 10 days after cord injury . KEY RESULTS : SCI in mice resulted in tissue damage , oedema , neutrophil infiltration , apoptosis , tumour necrosis-alpha (
P01375
REA
) and cyclooxygenase - 2 (
P35354
REA
) expression , prostaglandin E ( 2 ) ( PGE ( 2 ) ) and leukotriene B ( 4 ) (
Q06643
REA
( 4 ) ) production , and extracellular signal-regulated kinase 1/2 (
P27361
REA
/ 2 ) phosphorylation in injured tissue . Treatment of the mice with zileuton or montelukast reduced the spinal cord inflammation and tissue injury , neutrophil infiltration ,
P01375
REA
,
P35354
REA
and pERK 1/2 expression , PGE ( 2 ) and
Q06643
REA
( 4 ) production , and apoptosis . In separate experiments , zileuton or montelukast significantly improved the recovery of limb function over 10 days . CONCLUSIONS AND IMPLICATIONS : Zileuton and montelukast produced a substantial reduction of inflammatory events associated with experimental SCI . Our data underline the important role of
P09917
REA
and DB00151 - LT in neurotrauma .
10
An overview of phenserine tartrate , a novel acetylcholinesterase inhibitor for the treatment of Alzheimer ' s disease . Existing cholinesterase ( ChE ) inhibitor therapies for Alzheimer ' s disease ( AD ) , while effective in improving cognitive , behavioral and functional impairments , do not alter disease progression . Novel drug design studies have focused on the classical ChE inhibitor , ( - ) - physostigmine , producing alterations in chemical composition and three-dimensional structure , which may offer an improved therapeutic index . The phenylcarbamate derivative ,
DB04892
MEN
, is a selective , non-competitive inhibitor of acetylcholinesterase (
P22303
REA
) . In vivo ,
DB04892
MEN
produces rapid , potent , and long-lasting
P22303
REA
inhibition . As a possible result of its preferential brain selectivity ,
DB04892
MEN
is significantly less toxic than ( - ) - physostigmine . In studies using the Stone maze paradigm ,
DB04892
MEN
has been shown to improve cognitive performance in both young learning-impaired and elderly rats . In addition to reducing inactivation of acetylcholine in the brain ,
DB04892
MEN
appears to have a second mode of action . Reduced secretion of beta-amyloid ( Abeta ) has been observed in cell lines exposed to
DB04892
MEN
, occurring through translational regulation of beta-amyloid precursor protein ( beta -
P05067
REA
) mRNA via a non-cholinergic mechanism . These in vitro findings appear to translate in vivo into animal models and humans . In a small study of patients with AD ,
DB04892
MEN
treatment tended to reduce beta -
P05067
REA
and Abeta levels in plasma samples . Clinical studies also reveal that
DB04892
MEN
( 5-10 mg b . i . d . ) had a favorable safety and pharmacological profile , produced significant improvements in cognitive function and was well tolerated in patients with AD treated for 12 weeks . Further randomized , double-blind , placebo-controlled Phase III studies assessing the efficacy , safety / tolerability and potential disease-modifying effects of
DB04892
MEN
in patients with AD are currently ongoing .
11
P05067
REA
is a primary androgen target gene that promotes prostate cancer growth .
P10275
REA
( AR ) is a critical transcription factor that regulates various target genes and contributes to the pathophysiology of prostate cancer hormone dependently . Here , we identify amyloid precursor protein (
P05067
REA
) as a primary androgen target through chromatin immunoprecipitation ( ChIP ) combined with genome tiling array analysis ( ChIP-chip ) . ChIP-treated DNA were obtained from prostate cancer LNCaP cells with R1881 or vehicle treatment using AR or acetylated histone H3 antibodies . Ligand-dependent AR binding was further enriched by PCR subtraction . Using chromosome 21/22 arrays , we identified
P05067
REA
as one of the androgen-regulated genes with adjacent functional AR binding sites .
P05067
REA
expression is androgen-inducible in LNCaP cells and
P05067
REA
immunoreactivity was correlated with poor prognosis in patients with prostate cancer . Gain-of-function and loss-of-function studies revealed that
P05067
REA
promotes the tumor growth of prostate cancer . The present study reveals a novel
P05067
REA
- mediated pathway responsible for the androgen-dependent growth of prostate cancer . Our findings will indicate that
P05067
REA
could be a potential molecular target for the diagnosis and treatment of prostate cancer .
12
Modification of the reactivity of three amino-acid residues in elongation factor 2 during its binding to ribosomes and translocation . The accessibility of three amino acids of
P13639
REA
, located within highly conserved regions near the N - and C-terminal extremities of the molecule ( the E region and the
DB02059
MEN
region , respectively ) to modifying enzymes has been compared within nucleotide-complexed
P13639
REA
and ribosomal complexes that mimic the pre - and posttranslocational ones : the high-affinity complex (
P13639
REA
) - nonhydrolysable GTP analog GuoPP [ CH2 ] P ribosome and the low-affinity (
P13639
REA
) - GDP-ribosome complex ,
P13639
REA
and ribosomes being from rat liver . We studied the reactivity of two highly conserved residues diphthamide - 715 and DB00125 - 66 , to diphtheria-toxin-dependent ADP-ribosylation and trypsin attack , and of a threonine that probably lies between residues 51 and 60 , to phosphorylation by a Ca2 + / calmodulin-dependent protein kinase . DB03223 715 and this threonine residue were unreactive within the high-affinity complex but seemed fully reactive in the low-affinity complex . DB00125 - 66 was resistant to trypsin in both complexes . The possible involvement of the E and
DB02059
MEN
regions of
P13639
REA
in the interaction with ribosome in the two complexes is discussed .
13
P10275
REA
- mediated antagonism of estrogen-dependent low density lipoprotein receptor transcription in cultured hepatocytes . Postmenopausal women receiving hormone replacement therapy have a lower risk of coronary heart disease than women who do not receive hormone treatment . Multiple mechanisms are likely to underlie estrogen ' s cardioprotective action , including lowering of plasma low density lipoprotein ( LDL ) cholesterol . Using an in vitro system exhibiting normal regulation of
P01130
REA
(
P01130
REA
) gene transcription , we show that 17beta - estradiol activates the
P01130
REA
promoter in transiently transfected HepG 2 cells .
P01130
REA
activation by estrogen in HepG 2 cells is dependent on the presence of exogenous estrogen receptor , and the estrogen-responsive region of the
P01130
REA
promoter colocalizes with the sterol response element previously identified . The estrogen response is concentration dependent , saturable , and sensitive to antagonism by estrogen receptor antagonists . Further , we show that compounds with androgen receptor agonist activity attenuate the estrogen-induced up-regulation of
P01130
REA
in our model system . Progestins with androgen receptor agonist activity , such as medroxyprogesterone acetate , also suppress estrogen ' s effects on
P01130
REA
expression through their androgenic properties . Characterization of the interplay between these hormone receptors on the
P01130
REA
in vitro system may allow a better understanding of the actions of sex steroids on
P01130
REA
gene expression and their roles in cardiovascular disease .
14
Autophagy is induced through the ROS -
P04637
REA
- Q8N682 pathway in response to mitochondrial protein synthesis inhibition . Mitoribosome in mammalian cells is responsible for synthesis of 13 mtDNA-encoded proteins , which are integral parts of four mitochondrial respiratory chain complexes ( I , III , IV and V ) .
O75616
REA
is a nuclear-encoded GTPase important for the formation of the 28S small mitoribosomal subunit . Here , we demonstrate that knockdown of
O75616
REA
by RNA interference inhibits mitochondrial protein synthesis and promotes reactive oxygen species ( ROS ) generation , leading to autophagic vacuolization in HeLa cells . Cells that lack
O75616
REA
expression showed a significant conversion of LC3 - I to LC3 - II and an enhanced accumulation of autophagic vacuoles carrying the LC3 marker , all of which were blocked by the autophagy inhibitor 3 - MA as well as by the ROS scavenger
Q9C000
REA
. Inhibition of mitochondrial protein synthesis either by
O75616
REA
siRNA or chloramphenicol ( CAP ) , a specific inhibitor of mitoribosomes , induced autophagy in HTC - 116
P04637
REA
( + / + ) cells , but not in HTC - 116
P04637
REA
( - / - ) cells , indicating that tumor protein 53 (
P04637
REA
) is essential for the autophagy induction . The ROS elevation resulting from mitochondrial protein synthesis inhibition induced
P04637
REA
expression at transcriptional levels by enhancing
P04637
REA
promoter activity , and increased
P04637
REA
protein stability by suppressing
P04637
REA
ubiquitination through
Q16539
REA
/ p38 MAPK-mediated
P04637
REA
phosphorylation . Upregulation of
P04637
REA
and its downstream target gene Q8N682 , but not
P38936
REA
/
P38936
REA
, was required for the autophagy induction in
O75616
REA
siRNA or CAP-treated cells . Altogether , these data indicate that autophagy is induced through the ROS -
P04637
REA
- Q8N682 pathway in response to mitochondrial protein synthesis inhibition .
15
PP2Cdelta ( Ppm 1d ,
O15297
REA
) , an endogenous inhibitor of p38 MAPK , is regulated along with Trp 53 and Cdkn 2a following p38 MAPK inhibition during mouse preimplantation development . Preimplantation embryos utilize mitogen-activated protein kinase signaling ( MAPK ) pathways to relay signals from the external environment to prepare appropriate responses and adaptations to a changing milieu . It is therefore important to investigate how MAPK pathways are regulated during preimplantation development . This study was conducted to investigate whether PP2Cdelta ( Ppm 1d ,
O15297
REA
) is expressed during mouse preimplantation development and to determine the influences of p38 MAPK inhibition on expression of Trp 53 ( p53 ) , Ppm 1d , (
O15297
REA
) , and Cdkn 2a ( p16 ) during mouse preimplantation development . Our results indicate that Trp 53 , Ppm 1d , and Cdkn 2a mRNAs and TRP 53 and PP2Cdelta proteins are expressed throughout mouse preimplantation development . Treatment of 2 - cell embryos with
DB04338
MEN
( potent inhibitor of p38 MAPK alpha / beta /
Q16539
REA
/ 11 ) significantly increased Trp 53 , Ppm 1d and Cdkn 2a and Mapk 14 mRNA levels at 12 and 24 hr . Treatment of 8 - cell embryos with
DB04338
MEN
for 12 hr increased Trp 53 , Ppm 1d , and Cdkn 2a mRNA levels , but not Mapk 14 mRNA levels . Treatment of 8 - cell embryos for 24 hr increased Trp 53 , and Ppm 1d mRNA levels , but decreased Cdkn 2a and Mapk 14 mRNA levels . Therefore , blockade of p38 MAPK activity is associated with embryo stage specific influences on Trp 53 , Ppm 1d , Cdkn 2a , and Mapk 14 expression during mouse preimplantation development . These results define downstream targets of p38 MAPK during preimplantation development and indicate that the p38 MAPK pathway regulates Trp 53 , Ppm 1d , and Cdkn 2a expression . This study increases our understanding of the mechanisms controlling preimplantation development and of the interactions between preimplantation embryos and their culture environments .
16
Targeting eIF 4GI translation initiation factor affords an attractive therapeutic strategy in multiple myeloma . BACKGROUND : Deregulation of protein synthesis is integral to the malignant phenotype and translation initiation is the rate limiting stage . Therefore , eIF 4F translation initiation complex components are attractive therapeutic targets . METHODS : Protein lysates of myeloma cells ( cell lines / patients ' bone marrow samples ) untreated / treated with bevacizumab were assayed for eIF 4GI expression , regulation (
P15559
REA
/ proteosome dependent fragmentation ) ( WB ,
DB00266
MENMAX
DB00266
MEN
, qPCR ) and targets ( WB ) . eIF 4GI was inhibited by knockdown and 4EGI - 1 . Cells were tested for viability ( ELISA ) , death ( FACS ) and eIF 4GI targets ( WB ) . RESULTS : Previously , we have shown that manipulation of
P15692
REA
in myeloma cells attenuated
P06730
REA
dependent translation initiation . Here we assessed the significance of eIF 4GI to MM cells . We demonstrated increased expression of eIF 4GI in myeloma cells and its attenuation upon
P15692
REA
inhibition attributed to elevated
P15559
REA
/ proteasome dependent fragmentation and diminished mRNA levels . Knockdown of eIF 4GI was deleterious to myeloma cells phenotype and expression of specific molecular targets (
Q99717
REA
/ ERα / HIF 1α / c-Myc ) . Finally , we showed that the small molecule 4EGI - 1 inhibits eIF 4GI and causes a reduction in expression of its molecular targets in myeloma . CONCLUSION : Our findings substantiate that translation initiation of particular targets in MM is contingent on the function of eIF 4GI , critical to cell phenotype , and mark it as a viable target for pharmacological intervention .
17
Activity and potential role of licofelone in the management of osteoarthritis . Osteoarthritis is the most common form of arthritis . It is a progressive joint disease associated with aging . It may be found in the knees , hips , or other joints . It is estimated that costs associated with osteoarthritis exceed 2 % of the gross national product in developed countries . Nonsteroidal anti-inflammatory drugs ( NSAIDs ) are a mainstay in the treatment of inflammatory disease and are among the most widely used drugs worldwide . The main limitation in using NSAIDs consists in their side-effects , including gastrointestinal ulcerogenic activity and bronchospasm . The mechanism of action of these drugs is attributed to the inhibition of cyclooxygenase (
P36551
REA
) , and , consequently , the conversion of arachidonic acid into prostaglandins . It is hypothesized that the undesirable side-effects of NSAIDs are due to the inhibition of
P23219
REA
( constitutive isoform ) , whereas the beneficial effects are related to the inhibition of
P35354
REA
( inducible isoform ) . Arachidonic acid can also be converted to leukotrienes ( LTs ) by the action of
P09917
REA
( 5 - P28300 ) .
DB04725
MEN
, a P28300 /
P36551
REA
competitive inhibitor , decreases the production ofproinflammatory leukotrienes and prostaglandins ( which are involved in the pathophysiology of osteoarthritis and in gastrointestinal ( GI ) damage induced by NSAIDs ) and has the potential to combine good analgesic and anti-inflammatory effects with excellent GI tolerability . Preliminary data with this drug seem promising , but further well-designed clinical trials of this agent in the elderly will be necessary before a final evaluation is possible .
18
Current and future pharmacologic options for the management of patients unable to achieve low-density lipoprotein-cholesterol goals with statins . Low-density lipoprotein-cholesterol ( LDL-C ) lowering is the mainstay of the current treatment guidelines in the management of cardiovascular risk .
P04035
REA
inhibitors ( statins ) are currently the most effective LDL-C-lowering drugs . However , a substantial number of patients do not reach treatment targets with statins . Therefore , an unmet medical need exists for lipid-lowering drugs with novel mechanisms of action to reach the recommended cholesterol target levels , either by monotherapy or combination therapy . Upregulation of the
P01130
REA
with squalene synthase inhibitors has shown promising results in animal studies but the clinical development of the lead compound lapaquistat (
DB05317
MEN
) has recently been discontinued . DB00973 combined with statins allowed significantly more patients to reach their LDL-C targets . Other inhibitors of intestinal cholesterol absorption such as disodium ascorbyl phytostanol phosphate ( DB05449 ) and bile acid transport inhibitors have shown positive results in early development trials , whereas the prospect of acyl coenzyme A : cholesterol acyltransferase inhibition in cardiovascular prevention is dire . Selective inhibition of messenger RNA ( mRNA ) by antisense oligonucleotides is a new approach to modify cholesterol levels . The inhibition of apolipoprotein B mRNA is in advanced development and mipomersen sodium ( ISIS 301012 ) has shown striking results in phase II studies both as monotherapy as well as in combination with statins .
19
Metformin suppresses growth of human head and neck squamous cell carcinoma via global inhibition of protein translation . Head and neck squamous cell carcinoma ( HNSCC ) is the sixth leading cancer in the world ; the main risk factors are alcohol and tobacco use . Advancements in therapies have yet to improve the prognosis of HNSCC . The connection between diabetes and cancer is being recognized , and metformin has been shown to decrease cancer incidence in diabetic patients . Accordingly , here , for the first time , we investigated metformin ' s efficacy on the growth and viability of human HNSCC FaDU and Detroit cells . Our results show that metformin treatment ( 5-20 mM ) dose-dependently inhibits the growth of both cell lines . In FaDU cells , metformin caused 18-57 % and 35-81 % growth inhibition after 48 and 72 h treatments , respectively . Similarly , in Detroit 562 cells , 48 and 72 h metformin treatment resulted in 20-57 % and 33-82 % inhibition , respectively . Mechanistically , metformin caused G 1 arrest , which coincided with a decrease in the protein levels of CDKs ( 2 , 4 and 6 ) , cyclins ( D1 and E ) and CDK inhibitors ( p15 , p16 , p18 and p27 ) , but no change in p19 and
P38936
REA
. Metformin also decreased the levels of oncogenic proteins Skp 2 and β-Trcp . In other studies , metformin decreased the phosphorylation of
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at Ser 65 , Thr 37/46 and Thr 70 sites , but drastically increased the phosphorylation of
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at Thr 56 and AMPK at Thr 172 , which results in global translational inhibition . In summary , the observed wide spectrum of mechanistic effects of metformin on HNSCC cells provides support for the anticancer capability of the drug and its potential use in future therapies .