bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response to sublethal heat treatment of prostatic tumor cells and of prostatic tumor infiltrating T‐cells
Authors: Kramer Gero , Steiner Georg E. , Gröbl Marion , Hrachowitz Kristian , Reithmayr Franz , Paucz Ljubomir , Newman Martin , Madersbacher Stephan , Gruber Diego , Susani Martin , Marberger Michael 
Published: January 2004

AbstractBACKGROUNDTo investigate the possibilities offered by high intensity focused ultrasound (HIFU) in the field of tumor vaccination, we analyzed how prostatic cancer (CaP) cells react towards heat treatment and whether increased access to CaP cells by the immune system would be the result.METHODSHeat/stress response of CaP cells in situ and of CaP cell lines was analyzed by immunohistochemistry, Western blotting, and Atlas array. A heat‐induced change in immune recognition was analyzed functionally using human T‐helper (Th)1 and Th2‐cytokine release with tumor infiltrating T‐lymphocytes (TIL) as responder and autologous CaP cells either heated or untreated as stimulator cells.RESULTSTranscription of 68 out of 500 genes was upregulated by sublethal heat in LNCaP and PC3 cells. Significantly upregulated stress protein (SP) expression (HSP‐72, ‐73, GRP‐75, ‐78) was seen at the border zone of HIFU treatment. Remarkably, even untreated benign prostatic hyperplasia (BPH) specimens revealed relative overexpression of heat shock protein (HSP)‐72, ‐73 and glucose regulated protein (GRP)‐75, ‐78. Heated CaP cells increased Th1‐cytokine (IL‐2, IFN‐γ, TNF‐α) release but decreased Th2‐cytokine (IL‐4, ‐5, ‐10) release of TIL.CONCLUSIONSHIFU treatment may alter the presentation of prostate tissue and tumor antigens and this presentation is most likely stimulatory. HSP‐72/73 overexpression in untreated BPH may suggest a mechanism by which BPH can incite inflammation. © 2003 Wiley‐Liss, Inc.
Analysis of the inflammatory network in benign prostate hyperplasia and prostate cancer
Authors: König Jens Ekkehard , Senge Theodor , Allhoff Ernst Peter , König Wolfgang 
Published: January 2004

AbstractINTRODUCTIONThe complexity of acute and chronic inflammatory processes may either lead to benign prostate hyperplasia (BPH) and/or prostate cancer. Obviously, various tissue cells are activated by chemokines via different chemotaxin receptors which then trigger subsequent processes in angiogenesis, cellular growth, and extravasation as well as neoplasia.METHODSUsing the surgically obtained tissue of patients (n = 36) with BPH or prostate carcinoma (PCA), we studied among others the expression of chemokines (Rantes, IL‐8), chemotaxin receptors (CXCR‐3 and ‐4, CCR‐3, CCR‐5), of matrixmetalloproteinases (MMP‐2 and 9), of Toll‐like (TL) receptors 1, 2, 3, 4, 5, 7, and 9 and of the inducible cyclooxygenase‐2 (cox‐2) by RT‐PCR. Further support for the different properties of tissue from PCA was obtained using two different PCA cell lines (PC3 = androgen resistant cell) or LNCAP cells (androgen sensitive) with emphasis on IL‐8, Il‐6, and PGE2 release. Cell lines were stimulated with either the tumor necrosis factor‐α (TNF‐α) and lipopolysacharide (LPS) over time. In addition to cytokine release, the quantification of mRNA by lightcycler for cox‐2, IL‐6, and IL‐8 was performed on these cell lines.RESULTSRemarkable differences in expression were obtained by RT‐PCR when BPH tissue versus PCA was analyzed. Expression of CXCR‐1 after incubation with LPS and TNF‐α showed time‐dependent differences for androgen‐sensitive LNCAP as compared to androgen‐resistant PC‐3 cells. TNF‐α incubation leads to a time‐dependent induction of cox‐2 expression unlike to activation with LPS. Differences with regard to cox‐2, IL‐6, and IL‐8 expression were seen by quantitative lightcycler analysis. Significant differences were also observed when TL receptors 4, 5, 7, and 9 were analyzed which were significantly expressed in BPH‐ as compared to PCA‐tissue.CONCLUSIONSOur data clearly demonstrate that various inflammatory and cell biological cascades are involved which either lead to BPH or can be linked to the development of PCA. The exact cell biological mechanisms may provide novel therapeutic options in the treatment of both diseases. © 2003 Wiley‐Liss, Inc.
Comparative analysis of prostate‐specific membrane antigen (PSMA) versus a prostate‐specific membrane antigen‐like gene
Authors: O'Keefe Denise S. , Bacich Dean J. , Heston Warren D.W. 
Published: January 2004

AbstractBACKGROUNDCurrently prostate‐specific membrane antigen (PSMA) is showing promise both as an imaging and therapeutic target for occult prostate cancer metastases. First generation antibodies against PSMA are used for the FDA approved Prostascint™ monoclonal antibody scan and second generation antibodies are being developed for therapeutic targeting as well as imaging 1. However, there have been reports describing PSMA expression in non‐prostatic tissues including kidney, liver, and brain. As we had previously showed the existence of a human PSMA homolog, we set out to determine if this non‐prostatic expression was due to expression of the PSMA or another gene.MATERIALS AND METHODSThe PSMA homolog (PSMA‐like) cDNA was cloned by screening a liver cDNA library. mRNA expression of the PSMA and PSMA‐like genes was determined via Northern blot analysis using two different probes and protein expression confirmed in some tissues via Western blot analysis. Transcriptional regulation of the two genes was examined using reporter constructs driving luciferase expression.RESULTSThe PSMA‐like gene possesses 98% identity to the PSMA gene at the nucleotide level and is expressed in kidney and liver under the control of a different promoter to the PSMA gene. The PSMA gene is expressed in several human tissues and is most abundant in the nervous system and the prostate.CONCLUSIONThe non‐prostatic expression of PSMA should be taken into consideration when designing clinical strategies targeting PSMA. © 2003 Wiley‐Liss, Inc.
Expression of vascular endothelial growth factor receptor‐3 (VEGFR‐3) in human prostate
Authors: Li Rile , Younes Mamoun , Wheeler Thomas M. , Scardino Peter , Ohori Makato , Frolov Anna , Ayala Gustavo 
Published: January 2004

AbstractBACKGROUNDThe growth and dissemination of tumors has been associated with angiogenesis, which is regulated by a group of polypeptide factors including vascular endothelial growth factor‐C (VEGF‐C). VEGF‐C binds its receptor, vascular endothelial growth factor receptor‐3 (VEGFR‐3) to promote growth of tumor‐associated lymphatic vessels.METHODSIn this study, microarray technology was used to build tissue arrays of normal prostate, benign prostate hyperplasia (BPH) and prostate carcinomas (PCa) using tissues from 640 patients. Slides were sectioned and stained with a polyclonal antibody to VEGFR‐3 using a standard immunoperoxidase method and digitized. Immunoreactivity was scored using a 0–3+ semiquantitation scoring system for both intensity and percentage. The sum index was obtained by totaling the scores.RESULTSVEGFR‐3 is expressed in normal prostate, BPH, and PCa, but VEGFR‐3 expression is up‐regulated in PCa. We also found that VEGFR‐3 is correlated with pre‐operative prostate‐specific antigen (Pre‐PSA), Gleason score, and lymph node metastasis. The recurrence‐free 5‐year survival in cases with lower sum index (0–3) was significantly higher than that in cases with higher sum index (4–6) (77.3, 69.6%, respectively, P = 0.037) by Kaplan–Meier actuarial model.CONCLUSIONSOur data suggest that VEGFR‐3 expression is associated with tumor progression and may play an important role in facilitating lymphatic spread of PCa; high‐level of VEGFR‐3 expression in prostate cancer cells increases the risk of biochemical recurrence in prostate cancer patients treated by radical prostatectomy. © 2003 Wiley‐Liss, Inc.
Amphiregulin expression in prostatic intraepithelial neoplasia and adenocarcinoma: A study of 93 cases
Authors: Bostwick David G. , Qian Junqi , Maihle Nita J. 
Published: January 2004

AbstractBACKGROUNDAmphiregulin (AMP) is a heparin‐binding glycoprotein that is structurally and functionally related to epidermal growth factor. Its effects are mediated by the tyrosine kinase activity of the epidermal growth factor receptor (EGF‐R), and specific nuclear targeting sequences. AMP induces cell proliferation after androgen stimulation of human prostate cancer cell lines. An autocrine proliferative loop involving AMP, androgen, and EGF‐R may, therefore, play a role in prostatic carcinogenesis. The purpose of this study was to compare the expression of AMP in benign prostatic epithelium, high‐grade prostatic intraepithelial neoplasia (PIN), and adenocarcinoma.METHODSWe performed an immunohistochemical study of select sections from 93 radical prostatectomies performed at the Mayo Clinic between 1987 and 1991. All patients were previously untreated and found to have pathologic stage T2N0M0 adenocarcinoma after routine handling of surgical specimens. Affinity‐purified polyclonal antibody directed against AMP was applied to tissue sections using the streptavidin‐biotin method. For each case, the percentage of immunoreactive cells in benign epithelium, PIN, and adenocarcinoma was estimated in 10% increments. Intensity on a scale from 0 (negative) to 3 (strongly immunoreactive) and pattern of expression (nuclear versus cytoplasmic) also were recorded.RESULTSAMP immunoreactivity was present in benign prostatic epithelium, PIN, and prostatic adenocarcinoma in all cases. The mean percentage of AMP‐immunoreactive cells was 53.8% in benign epithelium, 65.9% in PIN, and 74.3% in cancer. Intensity was moderate in all cases. The pattern of expression was usually nuclear in benign epithelium (secretory and basal cells), and usually cytoplasmic or nuclear and cytoplasmic in PIN and adenocarcinoma. There were rare scattered immunoreactive cells in the stroma, ejaculatory duct epithelium, and urethral urothelium. Endothelial cells were invariably unstained.CONCLUSIONSAMP expression in prostate increases progressively from benign epithelium to PIN and cancer. Increased expression of AMP may contribute to the development of prostatic adenocarcinoma. Predominantly nuclear staining was observed in benign epithelium, whereas cytoplasmic or nuclear and cytoplasmic staining was observed in PIN and adenocarinoma. The differences in nuclear and cytoplasmic localization of immunoreactivity may reflect the presence of two pathways of activation, and hence varying biological functions of AMP. © 2003 Wiley‐Liss, Inc.
Use of the Gleason system in international comparisons of prostatic adenocarcinomas in blacks
Authors: Freeman Vincent L. , Coard Kathleen C.M. , Wojcik Eva , Durazo‐Arvizu Ramon 
Published: January 2004

AbstractBACKGROUNDComparisons of prostate cancer in blacks living in different countries can shed light on factors responsible for high rates of the disease among blacks in America. Since the prognostic value of the Gleason grading system is well established, we assessed agreement between pathologists in countries where black populations of the African Diaspora reside.METHODSThree genitourinary pathologists at hospitals in Nigeria, Jamaica, and the US independently assessed sextant biopsies from 12 patients. Gleason sum and percentage involvement were recorded, and a percent‐weighted average calculated. Agreement under different groupings was evaluated using the kappa statistic generalized to three raters.RESULTSAgreement was significant for individual sums (κ = 0.3317, P = 0.0173), sums grouped as well (2–4), moderately (5–6), and poorly differentiated (7–10) (κ = 0.2437, P < 0.0001) and other groupings. Agreement between at least two raters was 91.7–100%; complete agreement was 41.7–66.7%.CONCLUSIONSThe Gleason system is feasible and practical for international studies of prostate cancer among blacks from contrasting environments. Published 2003 Wiley‐Liss, Inc.
CD24 expression is a significant predictor of PSA relapse and poor prognosis in low grade or organ confined prostate cancer
Authors: Kristiansen Glen , Pilarsky Christian , Pervan Janja , Stürzebecher Burkhard , Stephan Carsten , Jung Klaus , Loening Stefan , Rosenthal Andre , Dietel Manfred 
Published: January 2004

AbstractBACKGROUNDThe prognostic impact of tumor grading and staging is markedly reduced in organ confined or moderately differentiated prostate cancer, which underscores the importance of new prognostic markers. Evaluating public expression data of prostate cancer, we found an upregulation of the candidate gene CD24.METHODSWe examined immunohistochemically the expression of CD24 protein in 31 nodal metastases and 102 adenocarcinomas of the prostate and correlated our findings to clinicopathological parameters.RESULTSCD24 expression was found in 48% of primary prostate cancer cases and in 68% of lymph node metastases. Kaplan Meier curves and Cox regression analysis showed that CD24 expression was strongly linked to significantly earlier disease progression (relative risk = 3.2), which was especially pronounced in organ confined, or moderately differentiated primary prostate tumors.CONCLUSIONSWe conclude that CD24 is an important prognostic tissue marker for prostate cancer which could help to define patients of low or high risk of recurrence. © 2003 Wiley‐Liss, Inc.
Dutasteride, the dual 5α–reductase inhibitor, inhibits androgen action and promotes cell death in the LNCaP prostate cancer cell line
Authors: Lazier C.B. , Thomas L.N. , Douglas R.C. , Vessey J.P. , Rittmaster R.S. 
Published: January 2004

AbstractBACKGROUNDReduction of T to DHT by 5αR in the prostate enhances androgenic activity for most targets. Inhibition of 5αR activity with finasteride attenuates androgen action in men and animal models. The objective of this study was to compare and contrast the effects of a potent new 5αR inhibitor, dutasteride, with finasteride in the LNCaP prostate cancer cell line.METHODSLNCaP cells were incubated for varying times with T or DHT in steroid‐free medium in the absence or presence of increasing doses of dutasteride or finasteride and the effects on 5αR activity, PSA accumulation in the medium, and on cell proliferation were determined. Drug effects on apoptosis were investigated using Annexin V staining and a cell death ELISA assay. Effects of the drugs on AR ligand‐binding activity and on AR protein levels were determined.RESULTSDutasteride inhibited 3H‐T conversion to 3H‐DHT and, as anticipated, inhibited T‐induced secretion of PSA and proliferation. However the drug also inhibited DHT‐induced PSA secretion and cell proliferation (IC50 ∼ 1 μM). Finasteride also inhibited DHT action but was less potent than dutasteride. Dutasteride competed for binding the LNCaP cell AR with an IC50 ∼ 1.5 μM. High concentrations of dutasteride (10–50 μM), but not finasteride, in steroid‐free medium, resulted in enhanced cell death, possibly by apoptosis. This was accompanied by loss of AR protein and decreased AR ligand‐binding activity. Occupation of AR by R1881 partly protected against cell death and loss of AR protein. PC‐3 prostate cancer cells, which do not contain AR, also were killed by high concentrations of dutasteride, as well as by 50 μM finasteride.CONCLUSIONSDutasteride exhibited some inhibitory actions in LNCaP cells possibly related to 5αR inhibition but also had antiandrogenic effects at relatively low concentrations and cell death‐promoting effects at higher concentrations. Finasteride also was antiandrogenic, but less than dutasteride. The antiandrogenic effects may be mediated by the mutant LNCaP cell AR. Promotion of cell death by dutasteride can be blocked, but only in part, by androgens. © 2003 Wiley‐Liss, Inc.
Molecular basis for redox‐Bohr and cooperative effects in cytochrome c3 from Desulfovibrio desulfuricans ATCC 27774: Crystallographic and modeling studies of oxidized and reduced high‐resolution structures at pH 7.6
Authors: Bento Isabel , Matias Pedro M. , Baptista António M. , da Costa Patricia N. , van Dongen Walter M.A.M. , Saraiva Lígia M. , Schneider Thomas R. , Soares Cláudio M. , Carrondo Maria A. 
Published: December 2003

AbstractThe tetraheme cytochrome c3 is a small metalloprotein with ca. 13,000 Da found in sulfate‐reducing bacteria, which is believed to act as a partner of hydrogenase. The three‐dimensional structure of the oxidized and reduced forms of cytochrome c3 from Desulfovibrio desulfuricans ATCC 27774 at pH 7.6 were determined using high‐resolution X‐ray crystallography and were compared with the previously determined oxidized form at pH 4.0. Theoretical calculations were performed with both structures, using continuum electrostatic calculations and Monte Carlo sampling of protonation and redox states, in order to understand the molecular basis of the redox‐Bohr and cooperativity effects related to the coupled transfer of electrons and protons. We were able to identify groups that showed redox‐linked conformational changes. In particular, Glu61, His76, and propionate D of heme II showed important contributions to the redox‐cooperativity, whereas His76, propionate A of heme I, and propionate D of heme IV were the key residues for the redox‐Bohr effect. Upon reduction, an important movement of the backbone region surrounding hemes I and II was also identified, that, together with a few redox‐linked conformational changes in side‐chain residues, results in a significant decrease in the solvent accessibility of hemes I and II. Proteins 2004. © 2003 Wiley‐Liss, Inc.
Enriching the sequence substitution matrix by structural information
Authors: Teodorescu Octavian , Galor Tamara , Pillardy Jaroslaw , Elber Ron 
Published: December 2003

AbstractA fundamental step in homology modeling is the comparison of two protein sequences: a probe sequence with an unknown structure and function and a template sequence for which the structure and function are known. The detection of protein similarities relies on a substitution matrix that scores the proximity of the aligned amino acids. Sequence‐to‐sequence alignments use symmetric substitution matrices, whereas the threading protocols use asymmetric matrices, testing the fitness of the probe sequence into the structure of the template protein. We propose a linear combination of threading and sequence‐alignment scoring function, to produce a single (mixed) scoring table. By fitting a single parameter (which is the relative contribution of the BLOSUM 50 matrix and the threading energy table of THOM2) we obtain a significant increase in prediction capacity in the twilight zone of homology modeling (detecting sequences with <25% sequence identity and with very similar structures). For a difficult test of 176 homologous pairs, with no signal of sequence similarity, the mixed model makes it possible to detect between 40 and 100% more protein pairs than the number of pairs that are detected by pure threading. Surprisingly, the linear combination of the two models is performing better than threading and than sequence alignment when the percentage of sequence identity is low. We finally suggest that further enrichment of substitution matrices, combing more structural descriptors such as exposed surface area, or secondary structure is expected to enhance the signal as well. Proteins 2003. © 2003 Wiley‐Liss, Inc.
Docking studies and model development of tea polyphenol proteasome inhibitors: Applications to rational drug design
Authors: Smith David M. , Daniel Kenyon G. , Wang Zhigang , Guida Wayne C. , Chan Tak‐Hang , Dou Q. Ping 
Published: December 2003

AbstractPreviously, we demonstrated that natural and synthetic ester bond‐containing green tea polyphenols were potent and specific non‐peptide proteasome inhibitors. However, the molecular mechanism of inhibition is currently unknown. Here, we report that inhibition of the chymotrypsin activity of the 20S proteasome by (−)‐epigallocatechin‐3‐gallate (EGCG) is time‐dependent and irreversible, implicating acylation of the β5‐subunit's catalytic N‐terminal threonine (Thr 1). This knowledge is used, along with in silico docking experiments, to aid in the understanding of binding and inhibition. On the basis of these docking experiments, we propose that (−)‐EGCG binds the chymotrypsin site in an orientation and conformation that is suitable for a nucleophilic attack by Thr 1. Consistently, the distance from the electrophilic carbonyl carbon of (−)‐EGCG to the hydroxyl group of Thr 1 was measured as 3.18 Å. Furthermore, the A ring of (−)‐EGCG acts as a tyrosine mimic, binding to the hydrophobic S1 pocket of the β5‐subunit. In the process, the (−)‐EGCG scissile bond may become strained, which could lower the activation energy for attack by the hydroxyl group of Thr 1. This model is validated by comparison of predicted and actual activities of several EGCG analogs, either naturally occurring, previously synthesized, or rationally synthesized. Proteins 2003. © 2003 Wiley‐Liss, Inc.
Improved thermostability of bacillus circulans cyclodextrin glycosyltransferase by the introduction of a salt bridge
Authors: Leemhuis Hans , Rozeboom Henriëtte J. , Dijkstra Bauke W. , Dijkhuizen Lubbert 
Published: December 2003

AbstractCyclodextrin glycosyltransferase (CGTase) catalyzes the formation of cyclodextrins from starch. Among the CGTases with known three‐dimensional structure, Thermoanaerobacterium thermosulfurigenes CGTase has the highest thermostability. By replacing amino acid residues in the B‐domain of Bacillus circulans CGTase with those from T. thermosulfurigenes CGTase, we identified a B. circulans CGTase mutant (with N188D and K192R mutations), with a strongly increased activity half‐life at 60°C. Asp188 and Arg192 form a salt bridge in T. thermosulfurigenes CGTase. Structural analysis of the B. circulans CGTase mutant revealed that this salt bridge is also formed in the mutant. Thus, the activity half‐life of this enzyme can be enhanced by rational protein engineering. Proteins 2003. © 2003 Wiley‐Liss, Inc.
Lipoxygenase interactions with natural flavonoid, quercetin, reveal a complex with protocatechuic acid in its X‐ray structure at 2.1 Å resolution
Authors: Borbulevych Oleg Y. , Jankun Jerzy , Selman Steven H. , Skrzypczak‐Jankun Ewa 
Published: December 2003

AbstractPUFA metabolites have a profound effect on inflammatory diseases and cancer progression. Blocking their production by inhibiting PUFA metabolizing enzymes (dioxygenases: cyclooxygenases and LOXs) might be a successful way to control and relieve such problems, if we learn to better understand their actions at a molecular level. Compounds with strong antioxidative and free radical scavenging properties, such as polyphenols, could be effective in blocking PUFA activities, and natural flavonoids possess such qualities. Quercetin belongs to the group of natural catecholic compounds and is known as a potent, competitive inhibitor of LOX. Structural analysis reveals that quercetin entrapped within LOX undergoes degradation, and the resulting compound has been identified by X‐ray analysis as protocatechuic acid (3,4‐dihydroxybenzoic acid) positioned near the iron site. Its C3‐OH group points toward His523, C4‐OH forms a hydrogen bond with OC from the enzyme's C‐terminus, and the carboxylic group is incorporated into the hydrogen bonding network of the active‐site neighborhood via Gln514. This unexpected result, together with our previous observations concerning other polyphenols, yields new evidence about the metabolism of natural flavonoids. These compounds might be vulnerable to the co‐oxidase activity of LOX, leading to enzyme‐stimulated oxidative degradation, which results in an inhibitor of a lower molecular weight. Proteins 2004;54:000–000. © 2003 Wiley‐Liss, Inc.