bluuebunny/crossref_metadata_2025_split huggingface dataset:
Src Induces Urokinase Receptor Gene Expression and Invasion/Intravasation via Activator Protein-1/p-c-Jun in Colorectal Cancer
Authors: Leupold Jörg H. , Asangani Irfan , Maurer Gabriele D. , Lengyel Ernst , Post Stefan , Allgayer Heike 
Published: May 2007

Abstract
The urokinase receptor [urokinase plasminogen activator receptor (u-PAR)] promotes invasion and metastasis and is associated with poor patient survival. Recently, it was shown that Src induces u-PAR gene expression via Sp1 bound to the u-PAR promoter region −152/−135. However, u-PAR is regulated by diverse promoter motifs, among them being an essential activator protein-1 (AP-1) motif at −190/−171. Moreover, an in vivo relevance of Src-induced transcriptional regulators of u-PAR–mediated invasion, in particular intravasation, and a relevance in resected patient tumors have not sufficiently been shown. The present study was conducted (a) to investigate if, in particular, AP-1–related transcriptional mediators are required for Src-induced u-PAR–gene expression, (b) to show in vivo relevance of AP-1–mediated Src-induced u-PAR gene expression for invasion/intravasation and for resected tissues from colorectal cancer patients. Src stimulation of the u-PAR promoter deleted for AP-1 region −190/−171 was reduced as compared with the wild-type promoter in cultured colon cancer cells. In gelshifts/chromatin immunoprecipitation, Src-transfected SW480 cells showed an increase of phospho–c-Jun, in addition to JunD and Fra-1, bound to region −190/−171. Src-transfected cells showed a significant increase in c-Jun phosphorylated at Ser73 and also Ser63, which was paralleled by increased phospho–c-jun-NH2-kinase. Significant decreases of invasion/in vivo intravasation (chorionallantoic membrane model) were observed in Src-overexpressing cells treated with Src inhibitors, u-PAR–small interfering RNA, and dominant negative c-Jun (TAM67). In resected tissues of 20 colorectal cancer patients, a significant correlation between Src activity, AP-1 complexes bound to u-PAR region −190/−171, and advanced pN stage were observed. These data suggest that Src-induced u-PAR gene expression and invasion/intravasation in vivo is also mediated via AP-1 region −190/−171, especially bound with c-Jun phosphorylated at Ser73/63, and that this pathway is biologically relevant for colorectal cancer patients, suggesting therapeutic potential. (Mol Cancer Res 2007;5(5):485–96)
TAT-RasGAP317-326 Requires p53 and PUMA to Sensitize Tumor Cells to Genotoxins
Authors: Michod David , Widmann Christian 
Published: May 2007

Abstract
Although chemotherapy has revolutionized cancer treatment, the associated side effects induced by lack of specificity to tumor cells remain a challenging problem. We have previously shown that TAT-RasGAP317-326,a cell-permeable peptide derived from RasGAP, specifically sensitizes cancer cells to the action of genotoxins. The underlying mechanisms of this sensitization were not defined however. Here, we report that TAT-RasGAP317-326 requires p53, but not the Ras effectors Akt and extracellular signal-regulated kinase, to mediate its tumor sensitization abilities. The TAT-RasGAP317-326 peptide, although not modulating the transcriptional activity of p53 or its phosphorylation and acetylation status, nevertheless requires a functional p53 cellular status to increase the sensitivity of tumor cells to genotoxins. Genes regulated by p53 encode proapoptotic proteins, such as PUMA, and cell cycle control proteins, such as p21. The ability of TAT-RasGAP317-326 to sensitize cancer cells was found to require PUMA but not p21. TAT-RasGAP317-326 did not affect PUMA levels, however, but increased genotoxin-induced mitochondrial depolarization and caspase-3 activation. These results indicate that TAT-RasGAP317-326 sensitizes tumor cells by activating signals that intersect with the p53 pathway downstream of, or at the level of, proapoptotic p53 target gene products to increase the activation of the mitochondrial death pathway. (Mol Cancer Res 2007;16(1):497–507)
Down-Regulation of Sprouty2 in Non–Small Cell Lung Cancer Contributes to Tumor Malignancy via Extracellular Signal-Regulated Kinase Pathway-Dependent and -Independent Mechanisms
Authors: Sutterlüty Hedwig , Mayer Christoph-Erik , Setinek Ulrike , Attems Johannes , Ovtcharov Slav , Mikula Mario , Mikulits Wolfgang , Micksche Michael , Berger Walter 
Published: May 2007

Abstract
Sprouty (Spry) proteins function as inhibitors of receptor tyrosine kinase signaling mainly by interfering with the Ras/Raf/mitogen-activated protein kinase cascade, a pathway known to be frequently deregulated in human non–small cell lung cancer (NSCLC). In this study, we show a consistently lowered Spry2 expression in NSCLC when compared with the corresponding normal lung epithelium. Based on these findings, we investigated the influence of Spry2 expression on the malignant phenotype of NSCLC cells. Ectopic expression of Spry2 antagonized mitogen-activated protein kinase activity and inhibited cell migration in cell lines homozygous for K-Ras wild type, whereas in NSCLC cells expressing mutated K-Ras, Spry2 failed to diminish extracellular signal-regulated kinase (ERK) phosphorylation. Nonetheless, Spry2 significantly reduced cell proliferation in all investigated cell lines and blocked tumor formation in mice. Accordingly, a Spry2 mutant unable to inhibit ERK phosphorylation reduced cell proliferation significantly but less pronounced compared with the wild-type protein. Therefore, we conclude that Spry2 interferes with ERK phosphorylation and another yet unidentified pathway. Our results suggest that Spry2 plays a role as tumor suppressor in NSCLC by antagonizing receptor tyrosine kinase–induced signaling at different levels, indicating feasibility for the usage of Spry in targeted gene therapy of NSCLC. (Mol Cancer Res 2007;5(5):509–20)
Assessment of Methylation Events during Colorectal Tumor Progression by Absolute Quantitative Analysis of Methylated Alleles
Authors: de Maat Michiel F.G. , Umetani Naoyuki , Sunami Eiji , Turner Roderick R. , Hoon Dave S.B. 
Published: May 2007

Abstract
To date, the epigenetic events involved in the progression of colorectal cancer are not well described. To study, in detail, methylation during colorectal cancer development in high-risk adenomas, we developed an assay combining in situ (on-slide) sodium bisulfite modification (SBM) of paraffin-embedded archival tissue sections with absolute quantitative assessment of methylated alleles (AQAMA). We tested the performance of the assay to detect methylation level differences between paired pre-malignant and malignant colorectal cancer stages. AQAMA assays were used to measure methylation levels at MINT (methylated in tumor) loci MINT1, MINT2, MINT12, and MINT31. Assay performance was verified on cell line DNA and standard cDNA. On-slide SBM, allowing DNA methylation assessment of 1 to 2 mm2 of paraffin-embedded archival tissue, was employed. Methylation levels of adenomatous and cancerous components within a single tissue section in 72 colorectal cancer patients were analyzed. AQAMA was verified as accurately assessing CpG island methylation status in cell lines. The correlation between expected and measured cDNA methylation levels was high for all four MINT AQAMA assays (R ≥ 0.966, P &lt; 0.001). Methylation levels at the four loci increased in 11% and decreased in 36% of specimens comparing paired adenoma and cancer tissues (P &lt; 0.0001 by Kolmogorov-Smirnov test). Single-PCR AQAMA provided accurate methylation level measurement. Variable MINT locus methylation level changes occur during malignant progression of colorectal adenoma. Combining AQAMA with on-slide SBM provides a sensitive assay that allows detailed histology-oriented analysis of DNA methylation levels and may give new, accurate insights into understanding development of epigenetic aberrancies in colorectal cancer progression. (Mol Cancer Res 2007;5(5):461–71)
p75 Neurotrophin Receptor Inhibits Invasion and Metastasis of Gastric Cancer
Authors: Jin Haifeng , Pan Yanglin , He Lijie , Zhai Huihong , Li Xiaohua , Zhao Lina , Sun Li , Liu Jie , Hong Liu , Song Jiugang , Xie Huahong , Gao Juan , Han Shuang , Li Ying , Fan Daiming 
Published: May 2007

Abstract
The p75 neurotrophin receptor (p75NTR) is a focus for study at present. However, its function in gastric cancer was not elucidated. Here, we investigated its relation with metastasis of gastric cancer. By immunohistochemistry, we found that the positive rate of p75NTR expression in metastatic gastric cancer was 15.09% (16 of 106), which was lower compared with nonmetastatic gastric cancer (64.15%; 68 of 106). The average staining score in nonmetastatic gastric cancer was significantly higher than in metastatic gastric cancer (1.21 ± 0.35 versus 0.23 ± 0.18; P &lt; 0.01). p75NTR protein level was also lowly expressed in the highly liver-metastatic gastric cancer cell line XGC9811-L compared with other gastric cancer cell lines by Western blotting. It could also significantly inhibit the in vitro adhesive, invasive, and migratory and in vivo metastatic abilities of gastric cancer cell lines SGC7901 and MKN45 by reducing urokinase-type plasminogen activator (uPA) and matrix metalloproteinase (MMP)-9 proteins and by increasing tissue inhibitor of matrix metalloproteinase (TIMP)-1 protein. Further studies showed that p75NTR could suppress the nuclear factor-κB (NF-κB) signal. SN50, a specific inhibitor of NF-κB, which could inhibit in vitro invasive and migratory abilities of gastric cancer cells, reduced expression of uPA and MMP9 proteins and increased expression of TIMP1 protein. Taken together, p75NTR had the function of inhibiting the invasive and metastatic abilities of gastric cancer cells, which was mediated, at least partially, by down-regulation of uPA and MMP9 proteins and up-regulation of TIMP1 protein via the NF-κB signal transduction pathway. Our studies suggested that p75NTR may be used as a new potential therapeutic target in metastatic gastric cancer. (Mol Cancer Res 2007;5(5):423–30)
Silencing of Cyclooxygenase-2 Inhibits Metastasis and Delays Tumor Onset of Poorly Differentiated Metastatic Breast Cancer Cells
Authors: Stasinopoulos Ioannis , O'Brien David R. , Wildes Flonne , Glunde Kristine , Bhujwalla Zaver M. 
Published: May 2007

Abstract
Cyclooxygenases (COX) are rate-limiting enzymes involved in the conversion of PLA2-mobilized arachidonic acid into prostaglandins and thromboxanes. COX-2 is a key mediator of inflammation during both physiologic and pathologic responses to endogenous stimuli and infectious agents. Its overexpression has been detected in different cancers, including that of the breast. Using RNA interference, we have reduced the expression of COX-2 in the highly malignant breast cancer cell line MDA-MB-231 below detectable levels in response to interleukin-1β or 12-O-tetradecanoylphorbol-13-acetate treatment. Microarray analysis showed that COX-2 silencing resulted in the loss of mRNA expression of several oncogenic markers, such as matrix metalloproteinase-1, chemokine (C-X-C motif) receptor 4, and interleukin-11, which have been correlated with poor disease outcome, and in the up-regulation of antimetastatic transcripts, such as thrombospondin-1 and Epstein-Barr-Induced 3. Cells lacking COX-2 were less able to invade reconstituted extracellular matrix than parental cells in vitro. Consistent with these changes, loss of COX-2 resulted in the abolition or the significant delay of tumor onset when the cells were injected in the mammary fat pad of severe combined immunodeficient mice. Finally, silencing of COX-2 resulted in the inhibition of metastasis to the lungs of severe combined immunodeficient mice after intravenous injection. These data show that silencing of COX-2 abolishes the metastatic potential of MDA-MB-231 cells in vivo. (Mol Cancer Res 2007;5(5):435–42)
Bone marrow CD8 cells down-modulate membrane IL-7Rα expression and exhibit increased STAT-5 and p38 MAPK phosphorylation in the organ environment.
Authors: Cassese Giuliana , Parretta Elisabetta , Pisapia Laura , Santoni Angela , Guardiola John , Di Rosa Francesca 
Published: May 2007

AbstractBy comparing mature CD8-cell turnover in different organs, we previously demonstrated that CD8 cells proliferate predominantly in the bone marrow (BM). To investigate the mechanisms underlying such increased turnover, we compared BM, lymph nodes, and spleen CD8 cells from untreated C57BL/6 mice regarding in vivo proliferation within the organ; in vitro response to interleukin-7 (IL-7), IL-15, IL-21; ex vivo expression of membrane CD127 (IL-7Rα), intracellular Bcl-2, phospho–STAT-5 (signal transducer and activator of transcription 5), phospho-p38 mitogen activated protein kinase (MAPK); and in vivo proliferation on adoptive transfer. In the BM, the proliferation rate was increased for either total CD8 cells or individual CD44 and CD122 subsets. In contrast, purified CD8+ cells from the BM did not show an enhanced in vitro proliferative response to IL-7, IL-15, and IL-21 compared with corresponding spleen cells. After transfer and polyinosinic-polycytidylic acid (polyI:C) treatment, both spleen-derived and BM-derived CD8 cells from congenic donors proliferated approximately twice more in the recipient BM than in spleen and lymph nodes. Our results suggest that BM CD8 cells are not committed to self-renewal, but rather are stimulated in the organ. Molecular events constantly induced in the CD8 cells within the BM of untreated mice include increase of both phosphorylated STAT-5 and phosphorylated p38 intracellular levels, and the reduction of CD127 membrane expression.
The SOCS box of suppressor of cytokine signaling-3 contributes to the control of G-CSF responsiveness in vivo
Authors: Boyle Kristy , Egan Paul , Rakar Steven , Willson Tracy A. , Wicks Ian P. , Metcalf Donald , Hilton Douglas J. , Nicola Nicos A. , Alexander Warren S. , Roberts Andrew W. , Robb Lorraine 
Published: May 2007

Abstract
Suppressor of cytokine signaling 3 (SOCS3) is a negative regulator of granulocyte-colony stimulating factor (G-CSF) signaling in vivo. SOCS proteins regulate cytokine signaling by binding, via their SH2 domains, to activated cytokine receptors or their associated Janus kinases. In addition, they bind to the elongin B/C ubiquitin ligase complex via the SOCS box. To ascertain the contribution of the SOCS box of SOCS3 to in vivo regulation of G-CSF signaling, we generated mice expressing a truncated SOCS3 protein lacking the C-terminal SOCS box (SOCS3ΔSB/ΔSB). SOCS3ΔSB/ΔSB mice were viable, had normal steady-state hematopoiesis, and did not develop inflammatory disease. Despite the mild phenotype, STAT3 activation in response to G-CSF signaling was prolonged in SOCS3ΔSB/ΔSB bone marrow. SOCS3ΔSB/ΔSB bone marrow contained increased numbers of colony-forming cells responsive to G-CSF and IL-6. Treatment of the mice with pharmacologic doses of G-CSF, which mimics emergency granulopoiesis and therapeutic use of G-CSF, revealed that SOCS3ΔSB/ΔSB mice were hyperresponsive to G-CSF. Compared with wild-type mice, SOCS3ΔSB/ΔSB mice developed a more florid arthritis when tested using an acute disease model. Overall, the results establish a role for the SOCS box of SOCS3 in the in vivo regulation of G-CSF signaling and the response to inflammatory stimuli.
Phospholipase C and myosin light chain kinase inhibition define a common step in actin regulation during cytokinesis
Authors: Wong Raymond , Fabian Lacramioara , Forer Arthur , Brill Julie A 
Published: May 2007

Abstract

Background
Phosphatidylinositol 4,5-bisphosphate (PIP2) is required for successful completion of cytokinesis. In addition, both PIP2 and phosphoinositide-specific phospholipase C (PLC) have been localized to the cleavage furrow of dividing mammalian cells. PLC hydrolyzes PIP2 to yield diacylglycerol (DAG) and inositol trisphosphate (IP3), which in turn induces calcium (Ca2+) release from the ER. Several studies suggest PIP2 must be hydrolyzed continuously for continued cleavage furrow ingression. The majority of these studies employ the N-substituted maleimide U73122 as an inhibitor of PLC. However, the specificity of U73122 is unclear, as its active group closely resembles the non-specific alkylating agent N-ethylmaleimide (NEM). In addition, the pathway by which PIP2 regulates cytokinesis remains to be elucidated.

Results
Here we compared the effects of U73122 and the structurally unrelated PLC inhibitor ET-18-OCH3 (edelfosine) on cytokinesis in crane-fly and Drosophila spermatocytes. Our data show that the effects of U73122 are indeed via PLC because U73122 and ET-18-OCH3 produced similar effects on cell morphology and actin cytoskeleton organization that were distinct from those caused by NEM. Furthermore, treatment with the myosin light chain kinase (MLCK) inhibitor ML-7 caused cleavage furrow regression and loss of both F-actin and phosphorylated myosin regulatory light chain from the contractile ring in a manner similar to treatment with U73122 and ET-18-OCH3.

Conclusion
We have used multiple inhibitors to examine the roles of PLC and MLCK, a predicted downstream target of PLC regulation, in cytokinesis. Our results are consistent with a model in which PIP2 hydrolysis acts via Ca2+ to activate myosin via MLCK and thereby control actin dynamics during constriction of the contractile ring.
Variation of the Myelin Oligodendrocyte Glycoprotein gene is not primarily associated with multiple sclerosis in the Sardinian population
Authors: Marrosu Maria Giovanna , Murru Raffaele , Costa Gianna , Melis Maria Cristina , Rolesu Marcella , Schirru Lucia , Solla Elisabetta , Cuccu Stefania , Secci Maria Antonietta , Whalen Michael B , Cocco Eleonora , Pugliatti Maura , Sotgiu Stefano , Rosati Giulio , Cucca Francesco 
Published: May 2007

AbstractBackgroundMultiple sclerosis (MS) is consistently associated with particular HLA-DRB1-DQB1haplotypes. However, existing evidence suggests that variation at these loci does not entirely explain association of the HLA region with the disease. TheMOGlocus is a prime positional and functional candidate for such additional predisposing effects but the analysis is complicated by the strong, albeit labyrinthine pattern of linkage disequilibrium in the region. Here we have assessed the association ofMOGvariation with MS in the Sardinian population to see if it represents an independent contributor to MS predisposition.ResultsAfter re-sequencing theMOGgene in 21 healthy parents of MS patients we detected 134 variants, 33 of which were novel. A set of 40 informative SNPs was then selected and assessed for disease association together with 1 intragenic microsatellite in an initial data set of 239 MS families. This microsatellite and 11 SNPs were found to be positively associated with MS, using the transmission disequilibrium test, and were followed up in an additional 158 families (total families analysed = 397). While in these 397 families, 8 markers showed significant association with MS, through conditional tests we determined that theseMOGvariants were not associated with MS independently of the mainDRB1-DQB1disease associations.ConclusionThese results indicate that variation within theMOGgene is not an important independent determinant of MS-inherited risk in the Sardinian population.
Phase variation and microevolution at homopolymeric tracts in Bordetella pertussis
Authors: Gogol Emily B , Cummings Craig A , Burns Ryan C , Relman David A 
Published: May 2007

Abstract

Background

Bordetella pertussis, the causative agent of whooping cough, is a highly clonal pathogen of the respiratory tract. Its lack of genetic diversity, relative to many bacterial pathogens, could limit its ability to adapt to a hostile and changing host environment. This limitation might be overcome by phase variation, as observed for other mucosal pathogens. One of the most common mechanisms of phase variation is reversible expansion or contraction of homopolymeric tracts (HPTs).

Results
The genomes of B. pertussis and the two closely related species, B. bronchiseptica and B. parapertussis, were screened for homopolymeric tracts longer than expected on the basis of chance, given their nucleotide compositions. Sixty-nine such HPTs were found in total among the three genomes, 74% of which were polymorphic among the three species. Nine HPTs were genotyped in a collection of 90 geographically and temporally diverse B. pertussis strains using the polymerase chain reaction/ligase detection reaction (PCR/LDR) assay. Six HPTs were polymorphic in this collection of B. pertussis strains. Of note, one of these polymorphic HPTs was found in the fimX promoter, where a single base insertion variant was present in seven strains, all of which were isolated prior to introduction of the pertussis vaccine. Transcript abundance of fimX was found to be 3.8-fold lower in strains carrying the longer allele. HPTs in three other genes, tcfA, bapC, and BP3651, varied widely in composition across the strain collection and displayed allelic polymorphism within single cultures.

Conclusion
Allelic polymorphism at homopolymeric tracts is common within the B. pertussis genome. Phase variability may be an important mechanism in B. pertussis for evasion of the immune system and adaptation to different niches in the human host. High sensitivity and specificity make the PCR/LDR assay a powerful tool for investigating allelic variation at HPTs. Using this method, allelic diversity and phase variation were demonstrated at several B. pertussis loci.
Purification and preliminary crystallization of alanine racemase from Streptococcus pneumoniae
Authors: Strych Ulrich , Davlieva Milya , Longtin Joseph P , Murphy Eileen L , Im Hookang , Benedik Michael J , Krause Kurt L 
Published: May 2007

Abstract

Background
Over the past fifteen years, antibiotic resistance in the Gram-positive opportunistic human pathogen Streptococcus pneumoniae has significantly increased. Clinical isolates from patients with community-acquired pneumonia or otitis media often display resistance to two or more antibiotics. Given the need for new therapeutics, we intend to investigate enzymes of cell wall biosynthesis as novel drug targets. Alanine racemase, a ubiquitous enzyme among bacteria and absent in humans, provides the essential cell wall precursor, D-alanine, which forms part of the tetrapeptide crosslinking the peptidoglycan layer.

Results
The alanine racemases gene from S. pneumoniae (alr

SP
) was amplified by PCR and cloned and expressed in Escherichia coli. The 367 amino acid, 39854 Da dimeric enzyme was purified to electrophoretic homogeneity and preliminary crystals were obtained. Racemic activity was demonstrated through complementation of an alr auxotroph of E. coli growing on L-alanine. In an alanine racemases photometric assay, specific activities of 87.0 and 84.8 U mg-1 were determined for the conversion of D- to L-alanine and L- to D-alanine, respectively.

Conclusion
We have isolated and characterized the alanine racemase gene from the opportunistic human pathogen S. pneumoniae. The enzyme shows sufficient homology with other alanine racemases to allow its integration into our ongoing structure-based drug design project.