bluuebunny/crossref_metadata_2025 huggingface dataset:
Frequent chromosome 9p losses in histologically normal nasopharyngeal epithelia from southern Chinese
Authors: Chan Andrew Siu Chung , To Ka Fai , Lo Kwok Wai , Ding Min , Li Xianghong , Johnson Philip , Huang Dolly Poon
Published: October 2002

Nasopharyngeal carcinoma (NPC) is a common cancer among the Chinese population in the southern part of China. The incidence of this cancer drops markedly in northern China. A 6‐ to 24‐fold difference exists between southern and northern Chinese. To investigate the early genetic events involved in the development of this cancer, we have examined loss of heterozygosity (LOH) on chromosome 9p, being one of the most frequent genetic alterations in NPC, in nasopharyngeal tissues including normal epithelia (NP), dysplastic lesions (DNP) and invasive carcinoma (NPC) from high‐risk and low‐risk regions. We found similar frequencies of 9p LOH in NPC from high‐risk (77.8%) and low‐risk (63.6%) regions (p = 0.43). In contrast, 45% of normal nasopharyngeal epithelia from the high‐risk region showed 9p LOH, while none of the NP from the low‐risk region showed such abnormalities (p = 0.002). Deletions of chromosome 9p were found in 66.7% dysplastic nasopharyngeal lesions. These findings suggest that LOH of chromosome 9p is an early event in the tumorigenesis of NPC. The increased risk of NPC in southern Chinese may be related to early loss of genetic materials as indicated by 9p LOH in the NP from high‐ and low‐risk regions. We also reported previously that Epstein‐Barr virus (EBV) latent infection was present in all high‐grade DNP and NPC but not in any NP from fetuses or normal adults. Thus, early genetic alterations such as 9p LOH may take place prior to EBV latent infection and expand clonally thereafter. © 2002 Wiley‐Liss, Inc.
A proposal for cervical screening information systems in developing countries
Authors: Marrett Loraine D. , Robles Sylvia , Ashbury Fredrick D. , Green Bo , Goel Vivek , Luciani Silvana
Published: October 2002

The effective and efficient delivery of cervical screening programs requires information for planning, management, delivery and evaluation. Specially designed systems are generally required to meet these needs. In many developing countries, lack of information systems constitutes an important barrier to development of comprehensive screening programs and the effective control of cervical cancer. Our report outlines a framework for creating such systems in developing countries and describes a conceptual model for a cervical screening information system. The proposed system is modular, recognizing that there will be considerable between‐region heterogeneity in current status and priorities. The proposed system is centered on modules that would allow for the assembly and computerization of data on Pap tests, since these represent the main screening modality at the present time. Additional modules would process data and create and maintain a screening database (e.g., standardize, edit, link and update modules) and allow for the integration of other types of data, such as cervical histopathology results. An open systems development model is proposed, since it is most compatible with the goals of local stakeholder involvement and capacity‐building. © 2002 Wiley‐Liss, Inc.
Long‐term effects of oral contraceptives on ovarian cancer risk
Authors: Bosetti Cristina , Negri Eva , Trichopoulos Dimitrios , Franceschi Silvia , Beral Valerie , Tzonou Anastasia , Parazzini Fabio , Greggi Stefano , La Vecchia Carlo
Published: October 2002

Several epidemiologic studies have reported a protective effect of oral contraceptives (OCs) on ovarian cancer. However, there remain open issues, including better quantification of time‐related factors such as time since last use, age at first use and time since first use. We performed a collaborative reanalysis of 6 case‐control studies conducted between 1978 and 1999 in the United Kingdom, Greece and Italy, including a total of 2,768 incident, histologically confirmed cases of epithelial ovarian cancer and 6,274 hospital controls under age 70 years. A reduced risk of ovarian cancer was found for ever‐ compared to never‐users [odds ratio (OR) = 0.66, 95% confidence interval (CI) 0.56–0.79], and a stronger reduction was observed for women who had used OCs for ≥5 years (OR = 0.50, 95% CI 0.33–0.76) compared to those who had used them for <5 years. The protective effect of OCs on ovarian cancer was consistent across strata of age, parity, menopausal status and family history of breast or ovarian cancer. After allowance for duration of use, no other time factor was related to ovarian cancer risk: the reduced risk was similar for women who stopped OC use ≥20 years before compared to <10 years; likewise, no significant modification of risk reduction was observed for age at first OC use and time since first OC use. The present analysis indicates that, after taking into account duration of OC use, the OC protection from ovarian cancer persists for a long time after stopping use. © 2002 Wiley‐Liss, Inc.
Oesophageal adenocarcinoma: A paradigm of mechanical carcinogenesis?
Authors: La Vecchia Carlo , Negri Eva , Lagiou Pagona , Trichopoulos Dimitrios
Published: October 2002

Incidence of adenocarcinoma of the oesophagus and gastric cardia is increasing in most developed countries and strongly associated with obesity and male gender. An underlying increase in the prevalence of gastro‐oesophageal reflux has generally been postulated. We suggest that the increase in frequency of reflux and the 2 associated forms of cancer can be explained by growing abdominal pressure brought about by increasing central obesity, most common among men, and sedentary lifestyle, including car use. Abdominal pressure is further accentuated mainly in men by the shift in Western male dressing towards the general use of belts. © 2002 Wiley‐Liss, Inc.
Relationship of uveal and cutaneous malignant melanoma in persons with multiple primary tumors
Authors: Shors Andrew R. , Iwamoto Satori , Doody David R. , Weiss Noel S.
Published: October 2002

Uveal and cutaneous melanomas differ in tumor biology, immunophenotypes and the demographic correlates of their occurrence. As a means to examine the possibility of some shared etiologic factors, we wished to learn if the 2 cancers occurred in the same individual more often than would be expected by chance. Data from the Surveillance, Epidemiology and End Results (SEER) program from 1973–1998 were utilized for this purpose. The number of persons who went on to develop a second melanoma was compared to that expected based on the incidence of each type of melanoma in the general population, after adjusting for age, sex, calendar year and residence. Given an initial cutaneous melanoma, there was a 10‐fold increased risk of developing a second cutaneous melanoma (95% confidence interval [CI] = 9.4–10.6). Persons with uveal melanoma went on to develop cutaneous melanoma 4.6 times (95% CI = 2.9–6.8) more often than the population at large. In contrast, persons with cutaneous melanoma were not subsequently diagnosed with uveal melanoma at an appreciably elevated rate (standardized incidence ratio [SIR] = 1.4; 95% CI = 0.5–3.0). While these data offer some support for the hypothesis that uveal and cutaneous melanomas have 1 or more etiologies in common, the lack of symmetry in the pattern of second uveal and second cutaneous melanomas remains unexplained. © 2002 Wiley‐Liss, Inc.
Chromosomal alterations in small cell lung cancer revealed by multicolour fluorescence in situ hybridization
Authors: Ashman J.N.E. , Brigham J. , Cowen M.E. , Bahia H. , Greenman J. , Lind M. , Cawkwell L.
Published: October 2002

Small cell lung cancer (SCLC) is a major cause of cancer related morbidity and mortality. Karyotypic studies have revealed numerous chromosomal aberrations in most SCLC however, classical G‐banding analysis is unable to fully characterise complex marker chromosomes. Recent developments in molecular cytogenetics now allow accurate identification of the chromosomal components of complicated rearrangements. We have applied the technique of multicolour fluorescence in situ hybridization (M‐FISH) in combination with comparative genomic hybridization (CGH) to the analysis of 5 SCLC cell lines and 1 primary tumour specimen to characterise the chromosomal abnormalities. CGH analysis identified many similarities between specimens, with frequent DNA copy number decreases on chromosomes 3p, 5q, 10, 16q, 17p and frequent gains on 3q, 1p, 1q and 14q. In contrast, M‐FISH analysis revealed a large number of structural abnormalities, with each specimen demonstrating an individual pattern of chromosomal translocations. Forty different translocations were identified with the vast majority (39) being unbalanced. Chromosome 5 was the most frequently rearranged chromosome (9 translocations) followed by chromosomes 2, 10 and 16 (6 translocations each). Further investigation of these frequently involved chromosomes is warranted to establish whether consistent break points are involved in these translocations, causing dysregulation of specific genes that are crucial for tumour progression and secondly to identify the affected genes. © 2002 Wiley‐Liss, Inc.
Mortality and incidence trends from esophagus cancer in selected geographic areas of China circa 1970–90
Authors: Ke Li
Published: October 2002

China was one of the countries with the highest esophagus cancer risk in the world during the 1970s. This report provides data on time trends of esophagus cancer incidence and mortality during the 1970s–90s in selected geographic areas of China. Information on newly diagnosed cancer cases and cancer deaths is based on data collected by local population‐based registries and Disease Surveillance Points (DSP). For the whole country, esophagus cancer mortality decreased slightly, 17.4 per 105 populations during 1990–92 in contrast to 18.8 per 105 populations in 1973–75. In the Linxian area, trends in the incidence and mortality rates for esophagus+gastric cardia cancer reversed over time; incidence rates increased significantly during 1959–72 but were decreased significantly on average −2.26% (95% Confidence Interval [CI]: −1.74, −2.77) and −1.10% (95% CI = −0.58, −1.62) per year for males and females, respectively, during 1972–97. In urban Shanghai, incidence trend for esophagus cancer decreased monotonically and significantly on average by −4.99% (95% CI = −4.28, −5.70) and −5.18% (95% CI = −4.99, −5.70) per year for males and females, respectively. In Nanao islet, esophagus+gastric cardia cancer mortality rates increased during 1970–82 but decreased slowly from 1982–99 (−0.96% per year; 95% CI = −0.14, −1.78). Our study indicates that incidence and mortality rates for esophagus or esophagus+gastric cardia cancer are now decreasing in China. The declines may be due to an unplanned success of prevention, such as changes in population dietary patterns and food preservation methods. © 2002 Wiley‐Liss, Inc.
Ganoderma lucidum extract induces cell cycle arrest and apoptosis in MCF‐7 human breast cancer cell
Authors: Hu Hongbo , Ahn Nam‐Shik , Yang Xinlin , Lee Yong‐Soon , Kang Kyung‐Sun
Published: October 2002

Although the pharmacology and clinical application of water extracts of Ganoderma lucidum have been extensively documented, little is known regarding its alcohol extract. In the present study, the anti‐tumor effect of an alcohol extract of Ganoderma lucidum was investigated using MCF‐7 cells. We found that the alcohol extract of Ganoderma lucidum inhibited cell proliferation in a dose‐ and time‐dependent manner, which might be mediated through up‐regulation of p21/Waf1 and down‐regulation of cyclin D1. Furthermore, this compound can directly induce apoptosis in MCF‐7 cells, which might be mediated through up‐regulation of a pro‐apoptotic Bax protein and not by the immune system. Our findings suggest that there are multiple mechanisms underlying the anti‐tumor effects of Ganoderma lucidum. © 2002 Wiley‐Liss, Inc.
Impact of multiple HPV infection on response to treatment and survival in patients receiving radical radiotherapy for cervical cancer
Authors: Bachtiary Barbara , Obermair Andreas , Dreier Bettina , Birner Peter , Breitenecker Gerhard , Knocke Tomas‐Hendrik , Selzer Edgar , Pötter Richard
Published: October 2002

To obtain information on the incidence and the clinical significance of infection with various types of the human papillomavirus (HPV) in cancer of the uterine cervix, we retrospectively examined the HPV status of 106 patients who had received radical radiotherapy for cervical cancer stages IB to IIIB. DNA was extracted from formalin‐fixed, paraffin‐embedded biopsies and PCR was carried out to identify HPV types 16, 18, 31, 35, 33 and 45. To detect additional HPV types, consensus PCR products were cloned and sequenced. A catalyzed signal‐amplified colorimetric in situ hybridization was carried out in 84 of 106 specimens as a positive control. Response to therapy, progression‐free survival (PFS) and cervical cancer‐specific survival (CCSS) were the statistical endpoints. Survival analysis was carried out using univariate and multivariate analysis (Cox regression). Ninety‐six patients (90.6%) were HPV‐positive and 42/96 (43.7%) were positive for multiple HPV types. Eight patients had persistent disease after radiotherapy. From these 8 patients, 7 were infected with multiple HPV types and only 1 patient had an infection with a single HPV type. After a median follow up period of 50 months, patients with multiple HPV infection had a significantly shorter PFS and CCSS compared to those with single HPV infection (24.8% and 34.9% vs. 64% and 60.8%, Log rank, p < 0.01 and 0.04). In multivariate analysis, the presence of multiple HPV types (RR 1.9), node status (RR 2.3), tumor size (RR 3.2) and histologic type (RR 4.8) were independent prognostic factors of CCSS. Our results demonstrate that the presence of multiple HPV types is associated with poor response and with reduced survival in cervical cancer patients who receive radiotherapy as the primary treatment. © 2002 Wiley‐Liss, Inc.
Genetic polymorphism in myeloperoxidase but not GSTM1 is associated with risk of lung squamous cell carcinoma in a Chinese population
Authors: Lu Wenfu , Xing Deyin , Qi Jun , Tan Wen , Miao Xiaoping , Lin Dongxin
Published: October 2002

Myeloperoxidase (MPO), an enzyme derived from neutrophils, metabolically activates a wide range of carcinogens, whereas glutathione S‐transferase M1 (GSTM1) detoxifies various electrophilic metabolites. A ‐463G→A polymorphism in the promoter region of the MPO gene diminishes the expression of MPO and has been consistently shown to be associated with reduced risk of lung cancer in different ethnic populations. In our study, we have assessed the role of this polymorphism in lung cancer risk in a Chinese population. Genotypes of MPO and GSTM1 were determined by PCR‐SSCP and multiplex PCR in 314 patients with lung cancer and 320 frequency‐matched controls. The allele frequency for MPO ‐463A was found to be 0.155 in controls and 0.114 in cases. Subjects with the MPO ‐463GG genotype were at an increased risk of squamous cell carcinoma (SCC) of the lung compared to those having at least one ‐463A variant allele (adjusted odds ratio [OR] 2.35; 95% confidence interval [CI] 1.40–3.94). Stratified analysis suggested an interaction between heavy smoking (≥26 pack‐years) and the MPO‐463GG genotype. The adjusted OR of lung SCC for those having MPO‐463GG genotype and smoked ≥26 pack‐years was 20.50 (95% CI 5.58–75.33) compared to 6.22 (95% CI 1.72–22.47) for those smoked ≥26 pack‐years but having at least one variant A allele (p = 0.023, test for homogeneity). This effect of the MPO polymorphism was not observed in lung adenocarcinoma. GSTM1 deletion was quite common in both controls (49.4%) and cases (50.3%) but was not associated with risk of lung cancer alone or in combination with the MPO polymorphism. Our results confirm the previous reports showing that the variant A allele of MPO has a protective effect against risk of lung cancer. © 2002 Wiley‐Liss, Inc.
DNase I sensitive site in the core region of the human β‐globin origin of replication
Authors: Djeliova Vera , Russev George , Anachkova Boyka
Published: October 2002

HeLa cells were synchronized at late G1, early S, and late S phase of the cell cycle by nocodazole treatment. The cells were permeabilized with Triton X‐100, digested with DNAse I, and extracted with 0.2 M ammonium sulfate to remove the digested chromatin. DNA was isolated from the residual chromatin attached to the nuclear matrix, digested with Hind III, and subjected to hybridization with [32P] labeled probe located upstream of the core region of the human β‐globin replication origin. The hybridization pattern revealed the existence of a DNase I sensitive site in the core region of the β‐globin replicator. The results suggest that association with the nuclear matrix induce alteration in the chromatin structure of the origin of replication that represents a more open chromatin configuration. J. Cell. Biochem. 87: 279–283, 2002. © 2002 Wiley‐Liss, Inc.
Roles for cytoplasmic polyadenylation in cell cycle regulation
Authors: Read Rebecca L. , Norbury Chris J.
Published: October 2002

Polyadenylation of eukaryotic mRNAs in the nucleus promotes their translation following export to the cytoplasm and is an important determinant of mRNA stability. An additional level of control of gene expression is provided by cytoplasmic polyadenylation, which activates translation of a number of mRNAs important in orchestrating cell cycle events in oocytes. Recent studies indicate that cytoplasmic polyadenylation may be a mechanism of translational activation that is more widespread in eukaryotic cells. Here we discuss the roles of a recently identified family of nucleotidyl transferases (encoded by the cid1 gene family) in cell cycle regulation. To date, this family has been characterised mainly in yeasts, but it is conserved throughout the eukaryotes. Biochemical studies have indicated that a subset of members of this family function as cytoplasmic poly(A) polymerases targeting specific mRNAs for translation. This form of translational control appears to be particularly important for cell cycle regulation following inhibition of DNA synthesis. J. Cell. Biochem. 87: 258–265, 2002. © 2002 Wiley‐Liss, Inc.
TNF‐α suppresses bone sialoprotein (BSP) expression in ROS17/2.8 cells
Authors: Samoto Hiroshi , Shimizu Emi , Matsuda‐Honjo Yuko , Saito Ryoichiro , Yamazaki Muneyoshi , Kasai Kazutaka , Furuyama Shunsuke , Sugiya Hiroshi , Sodek Jaro , Ogata Yorimasa
Published: October 2002

Tumor necrosis factor‐alpha (TNF‐α) is a major mediator of inflammatory responses in many diseases that inhibits bone formation and stimulates bone resorption. To determine molecular mechanisms involved in the suppression of bone formation we have analyzed the effects of TNF‐α on BSP gene expression. Bone sialoprotein (BSP) is a mineralized tissue‐specific protein that appears to function in the initial mineralization of bone. Previous studies have demonstrated that BSP mRNA expression is essentially restricted to fully‐differentiated cells of mineralized connective tissues and that the expression of BSP is developmentally regulated. Treatment of rat osteosarcoma ROS 17/2.8 cells with TNF‐α (10 ng/ml) for 24 h caused a marked reduction in BSP mRNA levels. The addition of antioxidant N‐acetylcysteine (NAC; 20 mM) 30 min prior to stimulation with TNF‐α attenuated the inhibition of BSP mRNA levels. Transient transfection analyses, using chimeric constructs of the rat BSP gene promoter linked to a luciferase reporter gene, revealed that TNF‐α (10 ng/ml) suppressed expression in all constructs, including a short construct (pLUC3; nts −116 to +60), transfected into ROS17/2.8 cells. Further deletion analysis of the BSP promoter showed that a region within nts −84 to −60 was targeted by TNF‐α, the effects which were inhibited by NAC and the tyrosine kinase inhibitor, herbimycin A (HA). Introduction of 2bp mutations in the inverted CCAAT box (ATTGG; nts −50 and −46), a putative cAMP response element (CRE; nts −75 to −68), and a FGF response element (FRE; nts −92 to −85) showed that the TNF‐α effects were mediated by the CRE. These results were supported by gel mobility shift assays, using a radiolabeled double‐stranded CRE oligonucleotide, which revealed decreased binding of a nuclear protein from TNF‐α‐stimulated ROS 17/2.8 cells. Further, the inhibitory effect of TNF‐α on CRE DNA–protein complex was completely abolished by NAC or HA treatment. These studies, therefore, show that TNF‐α suppresses BSP gene transcription through a tyrosine kinase‐dependent pathway that generates reactive oxygen species and that the TNF‐α effects are mediated by a CRE element in the proximal BSP gene promoter. J. Cell. Biochem. 87: 313–323, 2002. © 2002 Wiley‐Liss, Inc.
Proliferation marker pKi‐67 affects the cell cycle in a self‐regulated manner
Authors: Schmidt Mirko H.H. , Broll Rainer , Bruch Hans‐Peter , Duchrow Michael
Published: October 2002

The proliferation marker pKi‐67 is commonly used in research and pathology to detect proliferating cells. In a previous work, we found the protein to be associated with regulators of the cell cycle, controlling S‐phase progression, as well as entry into and exit from mitosis. Here we investigate whether pKi‐67 has a regulative effect on the cell cycle itself. For that purpose we cloned four fragments of pKi‐67, together representing nearly the whole protein, and an N‐terminal pKi‐67 antisense oligonucleotide into a tetracycline inducible gene expression system. The sense fragments were C‐terminally modified by addition of either a nuclear localization sequence (NLS) or a STOP codon to address the impact of their intracellular distribution. FACS based cell cycle analysis revealed that expression of nearly all pKi‐67 domains and the antisense oligonucleotide led to a decreased amount of cells in S‐phase and an increased number of cells in G2/M‐ and G1‐phase. Subsequent analysis of the endogenous pKi‐67 mRNA and protein levels revealed that the constructs with the most significant impact on the cell cycle were able to silence pKi‐67 transcription as well. We conclude from the data that pKi‐67 influences progression of S‐phase and mitosis in a self‐regulated manner and, therefore, effects the cell cycle checkpoints within both phases. Furthermore, we found pKi‐67 mediates an anti‐apoptotic effect on the cell and we verified that this marker, although it is a potential ribosomal catalyst, is not expressed in differentiated tissues with a high transcriptional activity. J. Cell. Biochem. 87: 334–341, 2002. © 2002 Wiley‐Liss, Inc.
BMP‐2, BMP‐4, and PDGF‐bb stimulate chemotactic migration of primary human mesenchymal progenitor cells
Authors: Fiedler Jörg , Röderer Götz , Günther Klaus‐Peter , Brenner Rolf E.
Published: October 2002

For bone development, remodeling, and repair; the recruitment of mesenchymal progenitor cells (MPC) and their differentiation to osteoblasts is mandatory. The process of migration is believed to be regulated in part by growth factors stored within the bone matrix and released by bone resorption. In this study, primary human MPCs and to osteoblasts differentiated progenitor cells were examined for chemotaxis in response to human basic fibroblast growth factor (rhbFGF), human transforming growth factor beta 1 (rhTGF‐β1), human platelet derived growth factor bb (rhPDGF‐bb), human bone morphogenetic protein‐2 (rhBMP‐2), and recombinant bone morphogenetic protein‐4 of Xenopus laevis (rxBMP‐4) from 0.001 to 1.0 ng/ml each. The results of migration were expressed as a chemotactic index (CI). Migration of primary human progenitor cells was stimulated by rhBMP‐2, rxBMP‐4, and rhPDGF‐bb in a dose‐dependent manner. The increase of CI was up to 3.5‐fold for rhBMP‐2, 3.6‐fold for rxBMP‐4, and up to 22‐fold for rhPDGF‐bb, whereas rhTGF‐β1 and rhbFGF did not stimulate cell migration in the concentration range tested. In contrast differentiated progenitor cells behave similar to primary human osteoblasts. RhBMP‐2, rhPDGF‐bb, and rhTGF‐β1 stimulated the migration from 2.2 to 2.4‐fold each, while rxBMP‐4 and rhbFGF reached only a CI of 1.7–1.6. The effect of rhBMP‐2, rxBMP‐4, and rhPDGF‐bb as chemoattractive proteins for primary human MPC, including the change in response to growth factors after differentiation suggests a functional role for recruitment of MPCs during bone development and remodeling, as well as fracture healing. J. Cell. Biochem. 87:305‐312, 2002. © 2002 Wiley‐Liss, Inc.
Retinoid signalling and gene expression in neuroblastoma cells: RXR agonist and antagonist effects on CRABP‐II and RARβ expression
Authors: Hewson Quentin Campbell , Lovat Penny E. , Pearson Andrew D.J. , Redfern Christopher P.F.
Published: October 2002

9‐cis Retinoic acid (RA) induces gene expression in neuroblastoma cells more effectively and with different kinetics than other RA isomers, and could be acting in part through Retinoid X Receptors (RXRs). The aim of this study was to characterise the effects of an RXR agonist and RXR homodimer antagonist on the induction of cellular RA binding protein II (CRABP‐II) and RA receptor‐β (RARβ) in neuroblastoma cells in response to different retinoids. The RXR agonist, LDG1069, was as effective as all‐trans RA in inducing gene expression, but less effective than 9‐cis RA. The RXR‐homodimer antagonist, LG100754, inhibited the induction of CRABP‐II mRNA in SH‐SY5Y neuroblastoma cells by 9‐cis RA or the RXR‐specific agonist LGD1069, but had no effect when used with all‐trans RA. Conversely, LG100754 did not inhibit induction of RARβ mRNA by 9‐cis or all‐trans RA, or by LGD1069. RAR‐ and RXR‐specific ligands used together induced CRABP‐II and RARβ as effectively as 9‐cis RA. These results demonstrate the value of combining RXR‐ and RAR‐specific ligands to regulate RA‐inducible gene expression. The possibility that RXR‐homodimers mediate, in part, the induction of CRABP‐II by 9‐cis RA and RXR‐specific ligands is discussed. J. Cell. Biochem. 87: 284–291, 2002. © 2002 Wiley‐Liss, Inc.
Hydrostatic pressure induces apoptosis in human chondrocytes from osteoarthritic cartilage through up‐regulation of tumor necrosis factor‐α, inducible nitric oxide synthase, p53, c‐myc, and bax‐α, and suppression of bcl‐2
Authors: Islam Najmul , Haqqi Tariq M. , Jepsen Karl J. , Kraay Matthew , Welter Jean F. , Goldberg Victor M. , Malemud Charles J.
Published: October 2002

Hydrostatic pressure (HP) is thought to increase within cartilage extracellular matrix as a consequence of fluid flow inhibition. The biosynthetic response of human articular chondrocytes to HP in vitro varies with the load magnitude, load frequency, as well as duration of loading. We found that continuous cyclic HP (5 MegaPascals (MPa) for 4 h; 1 Hz frequency) induced apoptosis in human chondrocytes derived from osteoarthritic cartilage in vitro as evidenced by reduced chondrocyte viability which was independent of initial cell densities ranging from 8.1 × 104 to 1.3 × 106 cells ml−1. HP resulted in internucleosomal DNA fragmentation, activation of caspase‐3, and cleavage of poly‐ADP‐ribose polymerase (PARP). At the molecular level, induction of apoptosis by HP was characterized by up‐regulation of p53, c‐myc, and bax‐α after 4 h with concomitant down‐regulation of bcl‐2 after 2 h at 5 MPa as measured by RT‐PCR. In contrast, β‐actin expression was unchanged. Real‐time quantitative RT‐PCR confirmed a HP‐induced (5 MPa) 1.3–2.6 log‐fold decrease in bcl‐2 mRNA copy number after 2 and 4 h, respectively, and a significant increase (1.9–2.5 log‐fold) in tumor necrosis factor‐α (TNF‐α) and inducible nitric oxide synthase (iNOS) mRNA copy number after 2 and 4 h, respectively. The up‐regulation of p53 and c‐myc, and the down‐regulation of bcl‐2 caused by HP were confirmed at the protein level by Western blotting. These results indicated that HP is a strong inducer of apoptosis in osteoarthritic human chondrocytes in vitro. J. Cell. Biochem. 87: 266–278, 2002. © 2002 Wiley‐Liss, Inc.
Amyloid β‐protein affects cholesterol metabolism in cultured neurons: Implications for pivotal role of cholesterol in the amyloid cascade
Authors: Gong Jian‐Sheng , Sawamura Naoya , Zou Kun , Sakai Juro , Yanagisawa Katsuhiko , Michikawa Makoto
Published: October 2002

Recently, we have found that alterations in cellular cholesterol metabolism are involved in promotion of tau phosphorylation (Fan et al. [2001] J. Neurochem. 76: 391–400; Sawamura et al. [2001] J. Biol. Chem. 276:10314–10319). In addition, we have shown that amyloid β‐protein (Aβ) promotes cholesterol release to form Aβ‐lipid particles (Michikawa et al. [2001] J. Neurosci. 21:7226–7235). These lines of evidence inspired us to conduct further studies on whether Aβ affects cholesterol metabolism in neurons, which might lead to tau phosphorylation. Here, we report the effect of Aβ1‐40 on cholesterol metabolism in cultured neurons prepared from rat cerebral cortex. Oligomeric Aβ1‐40 inhibited cholesterol synthesis and reduced cellular cholesterol levels in a dose‐ and time‐dependent manner, while freshly dissolved Aβ had no effect on cholesterol metabolism. However, oligomeric Aβ had no effect on the proteolysis of sterol regulatory element binding protein‐2 (SREBP‐2) or protein synthesis in cultured neurons. Oligomeric Aβ did not enhance lactate dehydrogenase (LDH) release from neuronal cells or decrease signals in the cultures reactive to 3,3′‐Bis[N,N‐bis(carboxymethyl)aminomethyl]fluorescein, hexaacetoxymethyl ester (calcein AM) staining, indicating that Aβ used in this experiment did not cause neuronal death during the time course of our experiments. Since alterations in cholesterol metabolism induce tau phosphorylation, our findings that oligomeric Aβ alters cellular cholesterol homeostasis may provide new insight into the mechanism underlying the amyloid cascade hypothesis. © 2002 Wiley‐Liss, Inc.
Cholesterol and pathological processes in Alzheimer's disease
Authors: Yanagisawa Katsuhiko
Published: October 2002

Fundamental questions on the pathogenesis of Alzheimer's disease (AD) are how nontoxic, soluble amyloid β‐protein (Aβ) is converted to its toxic, aggregated form and how functional tau is hyperphosphorylated to form neurofibrillary tangles. Growing evidence from recent biochemical and cell biological studies suggests that altered cholesterol metabolism in neurons may underlie such pathological processes. The possibility that cholesterol is a risk factor in the development of AD has also been supported by recent epidemiological studies. Based on this line of evidence, it is noteworthy to examine the potency of cholesterol‐lowering medicine and/or diet in suppressing the development or the progression of AD. © 2002 Wiley‐Liss, Inc.
Remarkable increase in the concentration of 8‐hydroxyguanosine in cerebrospinal fluid from patients with Alzheimer's disease
Authors: Abe Takashi , Tohgi Hideo , Isobe Chiaki , Murata Takahiko , Sato Chigumi
Published: October 2002

To investigate the possible role of oxidative RNA damage in the pathogenesis of Alzheimer's disease (AD), the concentrations of the oxidative stress marker 8‐hydroxyguanosine (8‐OHG) were measured in the cerebrospinal fluid (CSF) and the serum of patients with AD and control subjects. The concentration of 8‐OHG in CSF in AD patients was approximately fivefold that in controls (P < 0.001). The concentration of 8‐OHG in CSF decreased significantly with the duration of illness (rs = −0.48, P < 0.05) and the progression of cognitive dysfunctions (rs = 0.67, P < 0.01). However, the concentration of 8‐OHG in CSF showed no correlation with that in serum in both the controls and AD patients. In addition, the concentration of 8‐OHG in serum was not significantly altered in AD patients compared to that in controls, suggesting that the 8‐OHG concentrations in the CSF do not reflect those in serum and may be probably reflect those in brain tissue. These in vivo findings suggest a possible role of 8‐OHG and increased oxidative RNA damage in the early stage of the development of AD. © 2002 Wiley‐Liss, Inc.
Isoaspartate formation at position 23 of amyloid beta peptide enhanced fibril formation and deposited onto senile plaques and vascular amyloids in Alzheimer's disease
Authors: Shimizu Takahiko , Fukuda Hiroyuki , Murayama Shigeo , Izumiyama Naoki , Shirasawa Takuji
Published: October 2002

Senile plaques and amyloid‐bearing vessels consisting of fibrillar amyloid β peptides (Aβ) are characteristic neuropathological features of Alzheimer's disease (AD). Aβ undergo spontaneous post‐translational modifications, such as isomerization and racemization, at their aspartyl residues in AD brains. Here we present evidence that Aβ isomerized at position 23 are deposited on plaques and vascular amyloids using an anti‐isomerized Aβ antibody. In vitro experiments showed that isomerization at position 23, but not position 7, enhanced aggregation. Furthermore, Aβ with the Dutch mutation, but not the Flemish mutation, also showed greatly enhanced aggregation. These results suggest that mutations or modifications at positions Glu22 and Asp23 have a pathogenic role in the deposition of Aβ. The development and progression of sporadic AD may be accelerated by spontaneous isomerization at position 23 of Aβ. © 2002 Wiley‐Liss, Inc.
Gene expression profiling of 12633 genes in Alzheimer hippocampal CA1: Transcription and neurotrophic factor down‐regulation and up‐regulation of apoptotic and pro‐inflammatory signaling
Authors: Colangelo Vittorio , Schurr Jill , Ball Melvyn J. , Pelaez Ricardo Palacios , Bazan Nicolas G. , Lukiw Walter J.
Published: October 2002

Alterations in transcription, RNA editing, translation, protein processing, and clearance are a consistent feature of Alzheimer's disease (AD) brain. To extend our initial study (Alzheimer Reports [2000] 3:161‐167), RNA samples isolated from control and AD hippocampal cornu ammonis 1 (CA1) were analyzed for 12633 gene and expressed sequence tag (EST) expression levels using DNA microarrays (HG‐U95Av2 Genechips; Affymetrix, Santa Clara, CA). Hippocampal CA1 tissues were carefully selected from several hundred potential specimens obtained from domestic and international brain banks. To minimize the effects of individual differences in gene expression, RNA of high spectral quality (A260/280 ≥ 1.9) was pooled from CA1 of six control or six AD subjects. Results were compared as a group; individual gene expression patterns for the most‐changed RNA message levels were also profiled. There were no significant differences in age, postmortem interval (mean ≤ 2.1 hr) nor tissue pH (range 6.6–6.9) between the two brain groups. AD tissues were derived from subjects clinically classified as CDR 2‐3 (CERAD/NIA). Expression data were analyzed using GeneSpring (Silicon Genetics, Redwood City, CA) and Microarray Data Mining Tool (Affymetrix) software. Compared to controls and 354 background/alignment markers, AD brain showed a generalized depression in brain gene transcription, including decreases in RNA encoding transcription factors (TFs), neurotrophic factors, signaling elements involved in synaptic plasticity such as synaptophysin, metallothionein III, and metal regulatory factor‐1. Three‐ or morefold increases in RNAs encoding DAXX, cPLA2, CDP5, NF‐κBp52/p100, FAS, βAPP, DPP1, NFIL6, IL precursor, B94, HB15, COX‐2, and CEX‐1 signals were strikingly apparent. These data support the hypothesis of widespread transcriptional alterations, misregulation of RNAs involved in metal ion homeostasis, TF signaling deficits, decreases in neurotrophic support and activated apoptotic and neuroinflammatory signaling in moderately affected AD hippocampal CA1. © 2002 Wiley‐Liss, Inc.
Turnover of synaptic membranes: Age‐related changes and modulation by dietary restriction
Authors: Ando Susumu , Tanaka Yasukazu , Toyoda (nee Ono) Yuriko , Kon Kazuo , Kawashima Sei‐ichi
Published: October 2002

We examined age‐related changes in the turnover rates of synaptic membrane components that might underlie the decrease in synaptic functions in senescence. Synaptic membrane constituents were labeled in vivo with deuterium and the disappearance of the deuterated molecules from synaptic membranes was measured by mass spectrometry. The turnover rates of phosphatidylcholine, phosphatidylethanolamine, cholesterol, and synaptophysin were all shown to slow down with aging. Dietary restriction, which is known to retard various aging processes, was found to decrease the turnover rates of membrane lipid species. Consequently, the fatty acid composition in phospholipids remained unchanged in the synaptic plasma membranes of food restricted mice. In contrast, the turnover rate of synaptophysin was accelerated under dietary restriction. This may mean that increased turnover enhances the removal of damaged proteins from membranes. © 2002 Wiley‐Liss, Inc.
SCG10‐related neuronal growth‐associated proteins in neural development, plasticity, degeneration, and aging
Authors: Mori Nozomu , Morii Hiroshi
Published: October 2002

Neuronal growth‐associated proteins (nGAPs) are in general neuron‐specific gene products whose expression correlates tightly with neuronal process outgrowth and/or regeneration, and are mostly good downstream targets of neurotrophin stimulation. Expression of genes encoding nGAPs such as GAP‐43, SCG10, and stathmin is upregulated following lesioning of cortical and hippocampal regions of the adult rat brain. In the brains of aged animals, however, the magnitude of the response is reduced, whereas the time course of the response is mostly unchanged when compared with that for brains of young ones. Expression of GAP‐43 and stathmin is reduced by aging, and is also changed in age‐related neurodegenerative conditions such as Alzheimer's disease in humans. Certain nGAPs are induced during long‐term potentiation (LTP) and also during critical periods of song‐learning and ocular dominance column formation in birds and cats, respectively. Recent evidence further supports the idea that functional synaptic modulation is often associated with remodeling of synaptic structures. These results suggest that neurotrophin‐responsive nGAPs serve as molecular markers of neuronal plasticity during development and aging, and that the neuronal plasticity decreases, at least in certain neuronal circuits, in the aged brain and neurodegenerative diseases. Recent findings on the roles of stathmin and SCG10‐related proteins in microtubule destabilization and its functional block by phosphorylation further support the importance of the SCG10 family proteins in neuronal cytoskeletal regulation, particularly as to microtubule dynamics. We summarize here a decade of research on SCG10 and its related molecules with special interests to brain aging and disease. © 2002 Wiley‐Liss, Inc.
Death and survival of neuronal cells exposed to Alzheimer's insults
Authors: Niikura Takako , Hashimoto Yuichi , Tajima Hirohisa , Nishimoto Ikuo
Published: October 2002

Neuronal cell death is the central abnormality occurring in brains suffering from Alzheimer's disease (AD). The notion that AD is a disease caused by loss of neurons points toward suppression of neuronal death as the most important therapeutic target. Nevertheless, the mechanisms for neuronal death in AD are still relatively unclear. Three known mutant genes cause familial AD (FAD): amyloid precursor protein, presenilin 1, and presenilin 2. Detailed analysis of cytotoxic mechanisms of the FAD‐linked mutant genes reveals that they cause neuronal cell death at physiologically low expression levels. Unexpectedly, cytotoxic mechanisms vary depending on the type of mutations and genes, suggesting that various mechanisms for neuronal cell death are involved in AD patients. In support of this, activity‐dependent neurotrophic factor, basic fibroblast growth factor, and insulin‐like growth factor‐I can completely protect neurons from β‐amyloid (Aβ) cytotoxicity but exhibit incomplete or little effect on cytotoxicity by FAD mutant genes. By contrast, Humanin, a newly identified 24‐residue peptide, suppresses neuronal cell death by various FAD mutants and Aβ, whereas this factor has no effect on cytotoxicity from AD‐irrelevant insults. Studies investigating death and survival of neuronal cells exposed to AD insults will open a new horizon in developing therapy aimed at neuroprotection. © 2002 Wiley‐Liss, Inc.
Alzheimer's disease: β‐Amyloid protein and tau
Authors: Morishima‐Kawashima Maho , Ihara Yasuo
Published: October 2002

Research on the molecular pathogenesis of Alzheimer's disease (AD) has made great strides over the last decade. This progress is the result of protein chemical analysis of two extracellular and intracellular fibrillary lesions in AD brain conducted during the 1980s, which identified β‐amyloid protein (Aβ) and tau as their major components, respectively. Linkage analysis of familial AD identified four responsible genes: three causative genes (β‐amyloid precursor protein, presenilin 1, and presenilin 2) and one susceptibility gene (apolipoprotein E ϵ4). All those genes causing and predisposing to AD exhibit a common phenotype: an increased production of Aβ42, a longer, more amyloidogenic Aβ species, and/or its enhanced deposition. This observation was substantiated when presenilins were shown to be directly involved in Aβ production. Whereas Aβ deposition is relatively specific for AD, tau deposition is observed in various neurodegenerative diseases and is assumed to be intimately associated with neuronal loss. The genetic analysis of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP‐17) revealed the presence of mutations in the tau gene in affected members. Thus, tau can lead to intracellular tau deposits and neuronal loss, although the mechanism remains to be clarified. Taken together, Aβ might exert neurotoxicity through tau, leading to neuronal loss in the AD brain. © 2002 Wiley‐Liss, Inc.
Age‐related changes in central nervous system phosphatidylserine decarboxylase activity
Authors: Salvador Gabriela A. , López Frederico M. , Giusto Norma M.
Published: October 2002

A significant portion of brain phosphatidylethanolamine (PE) is synthesized by a pathway involving the mitochondrial enzyme phosphatidylserine decarboxylase (PSDC), in a process by which phosphatidylserine (PS) is transferred from the endoplasmic reticulum to mitochondria. Aging changes the fatty acid composition of brain phospholipids, PS and PE being the most affected. The present study was carried out to determine PSDC activity in cerebral cortex (CC) and cerebellum (CRBL) mitochondrial fraction from adult (4‐month‐old) and aged (30‐month‐old) rats and to compare these activities with that found in liver. To study the effect of 22:6n‐3 content on the PSDC activity, PSs from different sources were prepared: rPS (from bovine retina, containing 36 mol % of 22:6n‐3); adPS (from adult rat CC microsomal membranes, with 25 mole % 22:6n‐3 content) and agPS (from aged rat CC microsomal membranes, with 21 mole % 22:6n‐3 content). For aged CC PSDC, the preferred substrate was agPS (the physiological substrate for aged animals), whereas in adult CC PSDC the substrate preference was inverse (rPS > adPS > agPS). Furthermore, CRBL PSDC does not show any substrate preference based on 22:6n‐3 content. CRBL PSDC activity in aged membranes using agPS as substrate is lower than PSDC activity in adult membranes in the presence of adPS. These results indicate that under physiological conditions, cerebellar PSDC is inhibited during aging. Liver PSDC activity showed the same substrate preference in adult and aged rats as adult CC PSDC. These findings lead us to conclude that PSDC activity has a differential tissue‐dependent substrate preference characteristic of the aging process. © 2002 Wiley‐Liss, Inc.
Ultrastructural analysis of the paranodal junction of myelinated fibers in 31‐month‐old‐rats
Authors: Sugiyama Ichiro , Tanaka Kayoko , Akita Masumi , Yoshida Kazunari , Kawase Takeshi , Asou Hiroaki
Published: October 2002

Recent studies have revealed a significant decrease in white matter volume, including loss of myelin, with age but minimal decrease in gray matter volume (Guttmann et al., [1998] Neurology 50:972–978). Myelin is necessary for the rapid conduction of impulses along axons. Myelinated nerve includes various domains, the node of Ranvier, the paranodal region, the juxtaparanodal region and the internode. The paranodal junction may serve to anchor the myelin sheath to the axon. We analyzed the ultrastructure of the paranodal region in myelinated fibers from the aged rat brain. Severe alterations of myelinated fibers were observed in 31‐month‐old rats, resulting in the appearance of macrophages, splitting of the myelin sheath, myelin balloon formation and separation from the axon. Many paranodal retractions of myelinated axons occurred in the aged rats. It should be noted that the paranodal junction is functionally important, serving to anchor the myelin to the axon and that there is a diffusion barrier in the paranodal region. We analyzed myelin‐related proteins from young and aged rat brains. The 21.5‐kDa isoform of myelin basic protein (MBP) almost disappeared in the 31‐month‐old rats, whereas other myelin proteins were not significantly changed between young and aged rats. These results suggest that this isoform, a highly cationic charged major dense component protein that binds lipid bilayer in the membrane, may participate in the formation of a paranodal diffusion barrier at the myelin/noncompact membrane border. © 2002 Wiley‐Liss, Inc.
Expression patterns of immature neuronal markers PSA‐NCAM, CRMP‐4 and NeuroD in the hippocampus of young adult and aged rodents
Authors: Seki Tatsunori
Published: October 2002

Neurogenesis is known to continue in the adult hippocampus of mammals, including humans. The present experiments were undertaken to examine the nature of developing neurons generated in the dentate gyrus of young and older rodents using immature neuronal markers such as highly polysialylated neural cell adhesion molecules (PSA‐NCAM), collapsin response‐mediated protein‐4 (CRMP‐4) and NeuroD. Most PSA‐expressing cells are simultaneously positive for CRMP‐4 and NeuroD in young rats. More than half of the PSA‐positive cells were also positive for mature neuronal markers such as NeuN and MAP2, although the intensity of the immunoreactivities was relatively weak. BrdU analysis revealed that CRMP‐4 is expressed for a longer period than PSA in BrdU‐labeled neurons. The number of immature neurons expressing PSA, NeuroD or CRMP‐4 decreased in older rodents, but no qualitative difference was found in the expression patterns of these molecular markers between young and older rodents. These results suggest not only that immunohistochemistry, using a combination of these immature and mature neuronal markers, is helpful for clarifying the developmental state of newly generated neurons, but also that newly generated neurons in young adult and older rodents have similar properties. © 2002 Wiley‐Liss, Inc.
Role of mitochondrial dysfunction in Alzheimer's disease
Authors: Castellani Rudy , Hirai Keisuke , Aliev Gjumrakch , Drew Kelly L. , Nunomura Akihiko , Takeda Atsushi , Cash Adam D. , Obrenovich Mark E. , Perry George , Smith Mark A.
Published: October 2002

Abnormalities in mitochondrial function relate to the spectrum of pathological changes seen in Alzheimer's disease. Here we review the causes and consequences of mitochondrial disturbances in Alzheimer's disease as well as how this information might impact on therapeutic approaches to this disease. © 2002 Wiley‐Liss, Inc.