bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bone sialoprotein expression in primary human breast cancer is associated with bone metastases development
Authors: Bellahcène A. , Kroll M. , Liebens F. , Castronovo V. 
Published: February 2010

Abstract
Breast cancer metastasizes to bone more frequently than to any other organ, and over 80% of advanced breast cancer patients develop bone metastases. Our recent demonstration that human breast cancer cells express bone sialoprotein (BSP), a bone matrix protein, provides a possible clue for the selective affinity of breast cancer cells for bone. We tested the hypothesis that detection of BSP in primary human breast cancer could be a potential indicator of the ability of breast cancer cells to metastasize to bone. BSP expression was evaluated in the primary breast cancers of 39 patients using immunoperoxidase and two specific anti-BSP antibodies. None of these patients presented clinically or scintigraphically detectable bone metastases at the time of surgery. In the course of their disease, 22 patients developed clinically diagnosed bone metastases. Expression of BSP in breast cancer cells from patients who developed bone metastases was significantly higher (p = 0.008, according to the Mann-Whitney test) than in patients with no bone involvement. No association was found between BSP expression in the primary breast lesions and axillary lymph node metastases. BSP expression was significantly increased in infiltrating ductal carcinoma compared with infiltrating lobular carcinoma (p = 0.0023). No correlation was found between immunoreactivity to BSP antibodies and estrogen receptor (ER) status, progesterone receptor (PR) status, or age. Our data suggest that BSP could help to identify which women will develop bone metastases and provide new bases for the understanding of the molecular mechanism(s) responsible for breast cancer cells osteotropism.
Osteoclastic superoxide production and bone resorption: Stimulation and inhibition by modulators of NADPH oxidase
Authors: Darden Alix G. , Ries William L. , Wolf William C. , Rodriguiz Ramona Marie , Key L. Lyndon 
Published: February 2010

Abstract
Production of superoxide radicals by osteoclasts is necessary for normal bone degradation. White blood cell superoxide, needed for bacterial killing, is produced by activated NADPH oxidase. Since osteoclasts and white blood cells share a common hematopoietic origin, we initiated experiments to test the hypothesis that superoxide radicals at the osteoclast-bone interface are produced by NADPH oxidase. Diphenyl iodonium (IDP), an inhibitor of NADPH oxidase, blocked superoxide generation and decreased osteoclastic bone resorption in cultures of calvarial explants from normal mice. Interferon (IFN) gamma, a stimulant of NADPH oxidase activity, increased superoxide production and bone resorption in cultures of calvarial explants from osteopetrotic (microphthalmic) mice. IDP blocked the stimulatory effects of IFN in this bone resorption model. These data suggest that osteoclastic superoxide is produced by NADPH oxidase.
Unilateral hip replacement causes bilateral changes in tibial bone mineral content in a canine model
Authors: Smith Alberta M. , Turner Thomas M. , Sumner Dale R. 
Published: February 2010

Abstract
The presence of asymmetry in tibial bone mineral content (BMC) of the operated and control limbs at the end of the experimental period following unilateral hip replacement surgery is used as a marker of limb function. The goal of the present study was to determine the contribution of ipsilateral and contralateral bone gain and loss to control-treated side differences in BMC of the tibia in dogs following unilateral hip replacement surgery. Seven animals were followed longitudinally with single beam photon absorptiometry for 6 months after unilateral hip hemiarthroplasty. Bone loss, compared with preoperative baseline values, was observed in both limbs, with recovery in bone mass beginning 1 month after surgery in the contralateral tibia and 3 months after surgery in the ipsilateral tibia. Thus, the asymmetry in tibial BMC frequently seen after unilateral experimental hip replacement in the canine appears to be caused by differential timing of recovery of bone mass following a transient loss in both limbs. The mechanism defined in this study is in contrast to an alternative mechanism involving bone loss in the treated limb coupled with bone gain in the control limb.
Translational regulation of parathyroid hormone gene expression and RNA: Protein interactions
Authors: Vadher Shilpa , Hawa Nigar S. , O'Riordan Jeffrey L. H. , Dr. Farrow Sheelagh M. 
Published: February 2010

Abstract
The aim of this study was to investigate the mechanism by which translation of parathyroid hormone (PTH) mRNA is regulated with regard to the subcellular distribution of PTH mRNA and RNA:protein interactions. Sucrose density ultracentrifugation of RNA from bovine parathyroid cells indicated that there was no evidence for a pool of nonribosomal PTH mRNA, and the extracellular calcium concentration had no effect on polysome size. UV cross-linking studies revealed two proteins in parathyroid cell cytosol which bound specifically to the 5′-untranslated region (UTR) of PTH mRNA with molecular masses of 66 and 68 kD while proteins with apparent molecular masses of 48 and 70 kD bound to the 3′-UTR. In vitro translation assays indicated that parathyroid cell cytosol contains factors that inhibit translation of PTH mRNA. Fractionation of cytosol revealed that this effect was associated with proteins within the molecular mass range 30–90 kD. To determine which sequences in PTH mRNA mediate translational regulation, RNA was synthesized from luciferase gene constructs containing the 5′-and/or 3′-UTR of PTH mRNA, and translated in vitro. Addition of parathyroid cell cytosol reduced the translation of RNA containing the 5′- and 3′-UTR of PTH mRNA by 44 + 7% but had no effect on the translation of RNA containing only the luciferase coding region. Translation of RNA containing only the 5′-UTR of PTH mRNA was unchanged; however, cytosol reduced the translation of RNA containing the 3′-UTR by 31 + 9%. These data demonstrate a role for RNA:protein interactions in the regulation of PTH synthesis and that translational control is mediated primarily through interactions with the 3′-UTR of PTH mRNA.
Regulation of NFIL-6 and IL-6 expression by basic fibroblast growth factor in osteoblasts
Authors: Hurley Marja M. , Abreu Christine , Marcello Kristina , Kawaguchi Hiroshi , Lorenzo Joseph , Kalinowski Judith , Ray Anuradha , Gronowicz Gloria 
Published: February 2010

Abstract
We determined whether basic fibroblast growth factor (bFGF) regulated the expression of IL-6 and NFIL-6 in osteoblasts. In mouse osteoblastic MC3T3-E1 cells, bFGF (10−8 M) increased NFIL-6 mRNA 2-fold at 30 minutes and 3-fold at 2 h. IL-6 mRNA was increased by bFGF 10−8 M after 1 h. IL-6 protein was detectable in control cultures but was significantly increased by bFGF (10−8 M) at 4 h. Immunofluorescence analysis of MC3T3-E1 cells showed primarily cytoplasmic and perinuclear NFIL-6 staining in control cultures while bFGF-treated cells showed increased NFIL-6 staining at 2 and 4 h. Western blotting revealed that bFGF increased NFIL-6 protein at 2 h. In calvarial mouse osteoblasts, bFGF 10−8 M induced IL-6 mRNA as early as 1 h and significantly increased IL-6 protein levels as early as 2 h. In conclusion, bFGF stimulates IL-6 and NFIL-6 mRNA in osteoblasts. The increase in NFIL-6 mRNA was associated with increased NFIL-6 protein. The increase in IL-6 mRNA was also associated with increased IL-6 protein. We propose that activations of NFIL-6 and IL-6 may be important mediators of the effects of bFGF on bone cells.
Development and characterization of a conditionally transformed adult human osteoblastic cell line
Authors: Bodine Peter V.N. , Trailsmith Mark , Komm Barry S. 
Published: February 2010

Abstract
Many osteoblastic cell lines are currently in use, but these have limitations either in terms of their relevance to adult human biology and disease or in terms of their suitability for biochemical and molecular analyses. Consequently, we undertook the development of conditionally transformed adult human osteoblastic cell lines. Osteoblasts were obtained from a normal explant cancellous bone chip culture. These cells were infected with adenovirus-ori− SV40 tsA 209, which encodes a temperature-sensitive large T-antigen mutant. Cells immortalized with this virus express a transformed phenotype at the permissive temperature of 34°C but revert to a normal phenotype at the nonpermissive temperature of 40°C. Using this approach, we have isolated several cell clones and describe the characterization of one that was designated HOB-02-C1. Immunocytochemistry revealed that &gt;95% of the cells express the large T-antigen at both temperatures. These cells exponentially proliferate at 34°C with a doubling time of ˜2 days but irreversibly stop dividing at 40°C. However, cell volume increases &gt;2-fold when the cells are maintained for 6 days at the higher temperature. This clone expresses α1 type (I) procollagen mRNA and secretes type I procollagen C-peptide at both temperatures, although the levels were slightly elevated at 40°C. The cell line expresses alkaline phosphatase activity at 34°C, and the basal level of this enzyme increases 2- to 6-fold at 40°C. Alkaline phosphatase activity is induced 4- to 8-fold by 1α,25-dihydroxyvitamin D3 (vitamin D3) at both temperatures, but transforming growth factor-β1 (TGF-β1) suppresses enzyme expression &gt;90% at 40°C. Vitamin D3 also induces a 10-fold increase in osteocalcin secretion when the clone is maintained at 34°C, and this induction is enhanced &gt; 8-fold at 40°C. Parathyroid hormone and forskolin stimulate a 4- to 6-fold increase in the production of intracellular cyclic AMP (cAMP) by the cells at 34°C, and this stimulation is enhanced 2- to 4-fold at 40°C. In contrast, prostaglandin E2 stimulates a 7- to 8-fold increase in cAMP only when the cells are maintained at 34°C. This cell line secretes TGF-β1 and interleukin-6 (IL-6) at 34°C, but only the basal secretion of IL-6 increases 70% at 40°C. Finally, alizarin red-S histochemical staining demonstrates that these cells produce mineralized nodules at both temperatures. In summary, the results of this study indicate that the HOB-02-C1 cells have a mature osteoblastic phenotype. Consequently, this new cell line and others obtained in a similar fashion should be valuable in vitro tools for cellular, biochemical, and molecular studies of adult human osteoblast biology.
Vitamin D receptor gene polymorphisms are not related to bone turnover, rate of bone loss, and bone mass in postmenopausal women: The OFELY study
Authors: Garnero Patrick , Borel Olivier , Sornay-Rendu Elisabeth , Arlot Monique E. , Delmas Pierre D. 
Published: February 2010

Abstract
Vitamin D receptor (VDR) gene polymorphisms have been reported to account for most of the well established genetic influence on bone mineral density (BMD). However, discordant studies have been published and it is still not clear whether VDR genotypes influence bone mass accretion and/or postmenopausal bone loss. In this study, we analyzed VDR gene polymorphisms, i.e., that of BsmI, ApaI, and TaqI restriction enzymes in 268 untreated postmenopausal women 1–26 years postmenopausal. There were 37 BBAA homozygote (absence of BsmI and ApaI restriction sites on both alleles), 55 bbaa homozygote (presence of restriction sites on both alleles), and 176 heterozygotes. At baseline, women between the three genotypes did not differ significantly in age, years since menopause, body mass index (BMI), nor dietary calcium intake. We found no relationship between VDR genotypes and bone turnover assessed by three serum markers of bone formation and three urinary bone resorption markers, nor with BMD measured at the spine, hip, forearm, and whole body by dual-energy X-ray absorptiometry (DXA). Rates of bone loss assessed by repeated DXA measurements over 2 years were highly significant (p = 0.02–0.0001) at all skeletal sites except for the lumbar spine but did not differ between genotypes at any sites either before or after adjustment for potential confounding factors such as years since menopause, BMI, calcium intake, serum 25 hydroxyvitamin D levels, and baseline BMD. When we restricted the analysis to early postmenopausal women, within 10 years of menopause (n = 128), lumbar spine bone loss became significant, but no significant difference between VDR genotypes in the rate of bone loss measured at any site was found. We conclude that VDR genotypes are not predictive of bone turnover, rate of postmenopausal bone loss, and bone mass in either early or late postmenopausal women. In a subgroup of women with a low calcium intake (below 600 mg/day), we also found no significant differences between genotypes in BMD and the rate of bone loss measured at any site, although the sample size (n = 64) may be too small to detect small differences. In conclusion, these data, along with the absence of relationships between VDR gene polymorphisms and peak bone mass that we recently reported, suggest that the determination of VDR genotypes is probably not a useful clinical test for the risk assessment of osteoporosis.
Evidence-based medicine: New priority for an old paradigm
Authors: Feussner John R. 
Published: February 2010

Abstract
As outcomes research gains new importance in the practice of medicine, scientists publishing the results of clinical trials in JBMR must gain new appreciation for the elegant scientific methods and principles of analysis that make such investigations credible. Over the past year, during my tenure as Editor of the Journal, I have become progressively more interested in assuring that the clinical research reported in JBMR is of the highest quality. With this in mind, I asked John Feussner, M.D., a leading researcher in health outcomes investigations, to review recent manuscripts dealing with clinical trials that were published in JBMR and to search for areas in which we can make improvements. In the accompanying editorial, Dr. Feussner reports the result of his review. Not to my surprise, he was able to find errors of commission and omission that have affected several of the reported studies in the Journal. Although concern might be raised based upon reaching this conclusion from a review of a limited number of papers, it is more important to concentrate on the correctable factors that have been raised. Indeed, while many may consider this disquieting, I prefer to believe that the gauntlet has been thrown down and that we will respond to the challenges Dr. Feussner has provided us. In this regard, we must modify our clinical trials methodology and adhere to the principles that he has outlined in the accompanying editorial and allow that these principles guide our review of submitted manuscripts in the future. I believe that those of us in the editorial office are ready to refine the review process, paying newly directed attention to the methodological and analytical plans underlying clinical trials, and thereby move the quality of published clinical research in the Journal to even higher standards. The questions remains, however, Are you, the scientist/author and the scientist/reviewer, ready?
A novel gene expressed in rat ameloblasts codes for proteins with cell binding domains
Authors: Černý Radim , Slaby Ivan , Hammarström Lars , Wurtz Tilmann 
Published: February 2010

Abstract
Two variants of an mRNA sequence are identified that are expressed at high levels in rat ameloblasts during the formation of the enamel matrix. The sequences contain open reading frames for 407 and 324 amino acid residues, respectively. The encoded proteins, which we call amelins, are rich in proline, glycine, leucine, and alanine residues and contain the peptide domain DGEA, an integrin recognition sequence. The sequences coding for the C-terminal 305 amino acid residues, the 3′ nontranslated part, and a microsatellite repeat at the nontranslated 5′ region are identical in both mRNA variants. The remaining 5′ regions contain 338 nucleotides unique to the long variant, 54 common nucleotides, and 46 nucleotides present only in the short variant. Eleven nucleotides have the potential to code for 5 amino acids of both proteins in different reading frames. The reading frame of the longer variant includes codons for a typical N-terminal signal peptide. The amelins are likely to be constituents of the enamel matrix and the only proteins that have so far been implicated in binding interactions between the ameloblast surface and its extracellular matrix. (J Bone Miner Res 1996;11:883-891)
Herbimycin A, a tyrosine kinase inhibitor, impairs hypercalcemia associated with a human squamous cancer producing interleukin-6 in nude mice
Authors: Moriyama Keiji , Williams Paul J. , Niewolna Maria , Dallas Mark R. , Uehara Yoshimasa , Mundy Gregory R. , Yoneda Toshiyuki 
Published: February 2010

Abstract
Interleukin-6 (IL-6) is a multifunctional cytokine that is produced not only by a variety of normal cells but also by cancer cells. IL-6 produced by cancer cells stimulates the proliferation of these cancer cells in an autocrine/paracrine manner and causes paraneoplastic syndromes including hypercalcemia, cachexia, and leukocytosis. We have reported previously that a human oral squamous cancer associated with hypercalcemia produces large amounts of IL-6, that animals bearing this cancer exhibit elevated levels of plasma IL-6, and that neutralizing antibodies to human IL-6 reverse hypercalcemia in tumor-bearing animals, indicating an important role of IL-6 in the hypercalcemia in this model. Because these cancer cells overexpress epidermal growth factor receptors (EGFR) with intrinsic tyrosine kinase (TK) activity similar to many other squamous cancers, we examined the effects of herbimycin A, a tyrosine kinase inhibitor, on IL-6 production and hypercalcemia in animals bearing this cancer to develop a new approach to treat the hypercalcemia associated with malignancy. Intraperitoneal administration (once a day for 2 days) of herbimycin A to cancer-bearing hypercalcemic mice reduced the plasma levels of human IL-6 and impaired the hypercalcemia. During 2-day treatment with herbimycin A, no changes were observed in tumor size. Of interest, plasma levels of mouse, but not human, soluble IL-6 receptors were also elevated. However, herbimycin A showed no effects on plasma levels of mouse soluble IL-6 receptors. Herbimycin A suppressed the tyrosine autophosphorylation of EGFR and IL-6 mRNA expression and production, all of which were stimulated by EGF. The data raise the possibility that TK inhibitors may be potential mechanism-based therapeutic agents for the treatment of hypercalcemia associated with squamous cancers which overexpress EGFR. (J Bone Miner Res 1996;11:905-911)
High extracellular calcium stimulates osteoclast-like cell formation and bone-resorbing activity in the presence of osteoblastic cells
Authors: Kaji Hiroshi , Sugimoto Toshitsugu , Kanatani Masanori , Chihara Kazuo 
Published: February 2010

Abstract
The present study was performed to examine the effect of the high concentration of extracellular calcium ([Ca2+]e) on osteoclast-like cell formation and bone-resorbing activity in the presence or absence of osteoblasts. High [Ca2+]e (3 and 5 mM) significantly stimulated osteoclast-like cell formation in osteoblast-containing mouse bone cell cultures, although high [Ca2+]e did not affect the formation of osteoclast-like cells from hemopoietic blast cells supported by granulocyte-macrophage colony-stimulating factor in mouse spleen cell cultures. The osteoclast-like cells, newly formed by high [Ca2+]e in the presence of osteoblasts, possessed the ability to form pits on the dentine slices. The conditioned medium from osteoblastic MC3T3-E1 cells treated with high [Ca2+]e (5 mM) significantly increased the formation of osteoclast-like cells from hemopoietic blast cells, compared with the control medium. Dantrolene, an inhibitor of calcium mobilization from the intracellular calcium pool, and indomethacin significantly blocked high [Ca2+]e-stimulated osteoclast-like cell formation in the presence of osteoblasts, although voltage-dependent calcium channel blockers and anti-insulin-like growth factor I antibody did not affect it. High [Ca2+]e, however, significantly stimulated the bone-resorbing activity of mature osteoclasts in osteoblast-containing mouse bone cell cultures, although high [Ca2+]e inhibited bone-resorbing activity in isolated rabbit osteoclasts. An increase in the extracellular magnesium concentration (5 mM) affected neither osteoclast-like cell formation nor bone-resorbing activity. In conclusion, high [Ca2+]e stimulated osteoclast-like cell formation and bone-resorbing activity of mature osteoclasts, presumably via osteoblasts. (J Bone Miner Res 1996;11:912-920)
Progesterone and dexamethasone stimulate proliferation and differentiation of osteoprogenitors and progenitors for adipocytes and macrophages in cell populations derived from adult rat vertebrae
Authors: Ishida Yoichiro , Tertinegg Inka , Heersche Johan N. M. 
Published: February 2010

Abstract
We investigated the effects of the sex hormone progesterone (Prog) and the synthetic glucocorticoid dexamethasone (Dex) on proliferation and differentiation of progenitor cells of osteogenic, adipocytic, and hemopoietic lineages in cell populations derived from explants of adult female rat lumbar vertebrae. The cell populations were obtained by culturing bone explants in plasma clots immersed in α-minimum essential medium plus 10% fetal calf serum (standard medium) and then subculturing the outgrowth cells in standard medium plus 50 μg/ml of ascorbic acid, 5 mM β-glycerophosphate, and with or without Prog or Dex. On day 6 of culture, these populations were analyzed for cAMP responses to parathyroid hormone (PTH), prostaglandin E2 (PGE2), and isoproterenol (IPT). Increases in intracellular cAMP were seen in response to PTH, PGE2, and IPT, and culturing in medium containing Prog increased these responses. At various time periods between days 4–27 of culture, the cultures were evaluated for the presence of bone nodules, alkaline phosphatase (AP)-positive colonies, adipocytes, monocytes, and macrophages. Prog and Dex increased the number of bone nodules and AP-positive colonies. The effect of Prog on bone nodule formation was smaller than that of Dex. In addition, the effect of Dex on bone nodule formation was evident after 10 days of culture, while the Prog-induced effects became significant at days 16–20 of culture. Both hormones also increased the number of Sudan IV-positive colonies (adipocytes), certain types of α-naphthyl butyrate esterase (α-NBE)-positive colonies (monocytes, macrophages, and T-lymphocytes), and ED2-positive colonies (macrophages). Prog-treated cultures contained more colonies of small spindle-shaped α-NBE-positive cells and fewer colonies of small round α-NBE-positive cells when compared with Dex-treated cultures. These data indicate that cell populations derived from adult rat lumbar vertebrae contain, among others, osteoprogenitors and progenitors for adipocytes and macrophages that are stimulated to proliferate and differentiate by Prog and Dex. The data also suggest that the effects of Prog and Dex differ qualitatively and quantitatively. (J Bone Miner Res 1996;11:921–930)