Signal transduction of lipopolysaccharide-induced osteoclast differentiation.
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Acetylmuramyl-Alanyl-Isoglutamine↗
Biomedical subjects
Nobuaki Sato
Publications and source records attributed to Nobuaki Sato.
New 19-nor-(20S)-1alpha,25-dihydroxyvitamin D3 analogs strongly stimulate osteoclast formation both in vivo and in vitro.
2-Methylene-19-nor-(20S)-1alpha,25-dihydroxyvitamin D3 (2MD), an analog of 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3], has been shown to strongly induce bone formation both in vitro and in vivo. We have synthesized four substituents at carbon 2 of 2MD (2MD analogs), four stereoisomers at carbon 20 of the respective 2MD analogs (2MD analog-C20 isomers) and four 2MD analogs with an oxygen atom at carbon 22 (2MD-22-oxa analogs) and examined their ability to stimulate osteoclastogenesis and induce hypercalcemia. 2MD analogs were 100 times as potent as 1alpha,25(OH)2D3 in stimulating the formation of osteoclasts in vitro and in inducing the expression of receptor activator of NF-kappaB ligand (RANKL) and 25-hydroxyvitamin D3-24 hydroxylase mRNAs in osteoblasts. The osteoclast-inducing activities of 2MD analog-C20 isomers and 2MD 22-oxa analogs were much weaker than those of 2MD analogs. In addition, the activity of a 2MD analog in inducing dentine resorption was much stronger than that of 1alpha,25(OH)2D3 in the pit formation assay. Affinities to the vitamin D receptor and transcriptional activities of these compounds did not always correlate with their osteoclastogenic activities. Osteoprotegerin-deficient (OPG-/-) mice provide a suitable model for investigating in vivo effects of 2MD analogs because they exhibit extremely high concentrations of serum RANKL. The same amounts of 2MD analogs and 1alpha,25(OH)2D3 were administered daily to OPG-/- mice for 2 days. The elevation in serum concentrations of RANKL and calcium was much greater in 2MD analog-treated OPG-/- mice than in 1alpha,25(OH)2D3-treated ones. A 2MD analog was much more potent than 1alpha,25(OH)2D3 in causing hypercalcemia and in increasing soluble RANKL with enhanced osteoclastogenesis even in wild-type mice. In contrast, the administration of the 2MD analog to c-fos-deficient mice failed to induce osteoclastogenesis and hypercalcemia. These results suggest that new substituents at carbon 2 of 2MD strongly stimulate osteoclast formation in vitro and in vivo, and that osteoclastic bone resorption is indispensable for their hypercalcemic action of 2MD analogs in vivo.
Animals↗
Combination docetaxel and trastuzumab treatment for patients with HER-2-overexpressing metastatic breast cancer: a multicenter, phase-II study.
BACKGROUND: Pre-clinical and clinical studies indicate that a combination of docetaxel and trastuzumab may effectively treat patients with human epidermal growth factor receptor-2 (HER-2) overexpressing metastatic breast cancer. We evaluated the efficacy and safety of this combination in a multicenter, open-label phase II study in Japan. METHODS: Women with metastatic breast cancer whose tumors overexpressed HER-2, as assessed by immunohistochemistry and by fluorescence in situ hybridisation, received 2 to 6 cycles of docetaxel (70 mg/m2, every 3 weeks) and trastuzumab (4 mg/kg loading dose, 2 mg/kg weekly thereafter). The primary endpoint was tumor response. Secondary endpoints were time to disease progression and adverse events. RESULTS: Of the 40 women enrolled in the study, 27 (68%) completed 6 cycles of treatment. Three patients discontinued the study before the second cycle. Median follow-up was 20.8 months (range, 0.6 to 30.9 months). The overall response rate was 65% (26/40; 95% CI, 48% to 79%). The median time to progression was 6.8 months (range, 0.6 to 21.2 months). Of the 40 patients, 35 (88%) had grade 3 or 4 leukopenia, and 33 (83%) had grade 3 or 4 neutropenia. Most instances of leukopenia and neutropenia were manageable by reducing the dose of docetaxel or by treatment with granulocyte colony-stimulating factor. In 4 patients, left ventricular ejection fraction decreased by more than 10% from baseline. CONCLUSIONS: The combination of docetaxel and trastuzumab was as effective as reported in other similar studies and was well tolerated in these patients.
Adult↗
[Successful monotherapy with S-1 in three cases of recurrent/advanced breast cancer non-responsive to anthracycline and taxane anticancer drugs].
We had 3 patients with recurrent/advanced breast cancer in whom a notable reduction in the size of the targeted tumors was seen following administration of S-1 (TS-1), a new oral pyrimidine fluoride anticancer drug. All of the patients had received taxane and/or anthracycline anticancer drugs as prior therapy; however, they were judged to be non-responsive to the drugs. The size of the targeted tumor decreased to 55.7% after 3 courses of the therapy in Patient 1. The tumor disappeared at completion of the third course in Patient 2, although the therapy was temporarily suspended during the second course due to adverse drug reactions, and the therapy was then resumed after 2-week drug withdrawal. Patient 3 was able to undergo long-term therapy, consisting of 8 courses for 11 months, and the size of the tumor reduced to 58.1%. No serious adverse drug reactions to S-1 occurred in our 3 patients. It is thought that less toxicity enabled Patient 3 to undergo long-term therapy. We consider S-1 to be a useful anticancer drug for treatment of taxane and/or anthracycline resistant recurrent breast cancer.
Aged↗
[Bone destruction caused by osteoclasts].
Lipopolysaccharide (LPS) and muramyl dipeptide (MDP) are components of bacterial cell walls that cause innate immune responses and inflammation. Toll-like receptor 4 (TLR4) is a receptor for LPS and transduces signals through myeloid differentiation factor 88 (MyD88), which plays essential roles in the TLR/interleukin (IL)-1R signaling and activates MAP/ERK kinase (MEK)/ERK pathway to induce receptor activator of NF-kappaB ligand (RANKL) expression in osteoblasts. Osteoblasts express nucleotide oligomerization domain (NOD)2, an intracellular sensor for MDP, in response to LPS, IL-1 and TNF. NOD2 binds receptor-interacting protein (RIP2), a serine/threonine kinase which transduces NF-kappaB signaling. MDP synergistically enhances osteoclast formation induced by LPS, IL-1 and TNF through RANK ligand up-regulation in osteoblasts. TLR4 and NOD2 recognize bacterial components on cell surfaces and inside cells, respectively, and these signals up-regulate RANKL expression in osteoblasts, which results in enhancing osteoclast formation and function.
Acetylmuramyl-Alanyl-Isoglutamine↗
[Multicenter phase II trial of thrice-weekly docetaxel and weekly trastuzumab as preoperative chemotherapy in patients with HER 2-overexpressing breast cancer--Japan East Cancer Center Breast Cancer Consortium (JECBC) 02 Trial].
The efficacy and safety of combination therapy of 4 cycles with docetaxel 70 mg/m(2)every 3 weeks and trastuzumab as primary chemotherapy for operable breast cancer was determined in 21 patients (pts) by assessing the pathological complete response (pCR) rate, clinical response rate (RR), breast conservation surgery (BCS) rate and toxicities. To date, 19 pts have completed surgery. The pCR rate was 21% [95% CI 6%-46%] . The overall RR was 90% [95% CI 67%-99%] , with 5 CR, 12 PR, 2 SD and 0 PD. Grade 3 or 4 adverse events were leukopenia 48%, neutropenia 67%, hemoglobin 5%, and febrile neutropenia 10%. All non-hematological toxicities were mild and manageable. The pCR rate is not as low as that achieved in previous international studies. The combination of docetaxel and trastuzumab was a well-tolerated and very active regimen for the treatment of patients with HER 2-overexpressing operable breast cancer. This regimen promises to be one of the leading future treatments for progressive breast cancer.
Adult↗
The neuroprotective action of JNK3 inhibitors based on the 6,7-dihydro-5H-pyrrolo[1,2-a]imidazole scaffold.
Imidazole-based structures of p38 inhibitors served as a starting point for the design of JNK3 inhibitors. Construction of a 6,7-dihydro-5H-pyrrolo[1,2-a]imidazole scaffold led to the synthesis of the (S)-enantiomers, which exhibited p38/JNK3 IC50 ratio of up to 10 and were up to 20 times more potent inhibitors of JNK3 than the relevant (R)-enantiomers. The JNK3 inhibitory potency correlated well with inhibition of c-Jun phosphorylation and neuroprotective properties of the compounds in low K+-induced cell death of rat cerebellar granule neurones.
Animals↗
An efficient synthesis of methyl 1,3-O-isopropylidene-alpha-D-fructofuranoside and 2,3:5,6-di-O-isopropylidene-D-glucose dimethyl acetal derivatives from sucrose.
Acetalation of sucrose with 2,2-dimethoxypropane in 1,4-dioxane in the presence of p-toluenesulfonic acid, followed by acetylation, afforded methyl 4,6-di-O-acetyl-1,3-O-isopropylidene-alpha-D-fructofuranoside and 4-O-acetyl-2,3:5,6-di-O-isopropylidene-D-glucose dimethyl acetal as major products, while tosylation of the intermediate acetals provided methyl 6-O-tosyl-1,3-O-isopropylidene-alpha-D-fructofuranose.
Alkenes↗
Muramyl dipeptide enhances osteoclast formation induced by lipopolysaccharide, IL-1 alpha, and TNF-alpha through nucleotide-binding oligomerization domain 2-mediated signaling in osteoblasts.
Muramyl dipeptide (MDP) is the minimal essential structural unit responsible for the immunoadjuvant activity of peptidoglycan. As well as bone-resorbing factors such as 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3) and PGE2, LPS and IL-1alpha stimulate osteoclast formation in mouse cocultures of primary osteoblasts and hemopoietic cells. MDP alone could not induce osteoclast formation in the coculture, but enhanced osteoclast formation induced by LPS, IL-1alpha, or TNF-alpha but not 1alpha,25(OH)2D3 or PGE2. MDP failed to enhance osteoclast formation from osteoclast progenitors induced by receptor activator of NF-kappaB ligand (RANKL) or TNF-alpha. MDP up-regulated RANKL expression in osteoblasts treated with LPS or TNF-alpha but not 1alpha,25(OH)2D3. Osteoblasts expressed mRNA of nucleotide-binding oligomerization domain 2 (Nod2), an intracellular sensor of MDP, in response to LPS, IL-1alpha, or TNF-alpha but not 1alpha,25(OH)2D3. Induction of Nod2 mRNA expression by LPS but not by TNF-alpha in osteoblasts was dependent on TLR4 and MyD88. MDP also enhanced TNF-alpha-induced osteoclast formation in cocultures prepared from Toll/IL-1R domain-containing adapter protein (TIRAP)-deficient mice through the up-regulation of RANKL mRNA expression in osteoblasts, suggesting that TLR2 is not involved in the MDP-induced osteoclast formation. The depletion of intracellular Nod2 by small interfering RNA blocked MDP-induced up-regulation of RANKL mRNA in osteoblasts. LPS and RANKL stimulated the survival of osteoclasts, and this effect was not enhanced by MDP. These results suggest that MDP synergistically enhances osteoclast formation induced by LPS, IL-1alpha, and TNF-alpha through RANKL expression in osteoblasts, and that Nod2-mediated signals are involved in the MDP-induced RANKL expression in osteoblasts.
Acetylmuramyl-Alanyl-Isoglutamine↗
MyD88 but not TRIF is essential for osteoclastogenesis induced by lipopolysaccharide, diacyl lipopeptide, and IL-1alpha.
Myeloid differentiation factor 88 (MyD88) plays essential roles in the signaling of the Toll/interleukin (IL)-1 receptor family. Toll-IL-1 receptor domain-containing adaptor inducing interferon-beta (TRIF)-mediated signals are involved in lipopolysaccharide (LPS)-induced MyD88-independent pathways. Using MyD88-deficient (MyD88-/-) mice and TRIF-deficient (TRIF-/-) mice, we examined roles of MyD88 and TRIF in osteoclast differentiation and function. LPS, diacyl lipopeptide, and IL-1alpha stimulated osteoclastogenesis in cocultures of osteoblasts and hemopoietic cells obtained from TRIF-/- mice, but not MyD88-/- mice. These factors stimulated receptor activator of nuclear factor-kappaB ligand mRNA expression in TRIF-/- osteoblasts, but not MyD88-/- osteoblasts. LPS stimulated IL-6 production in TRIF-/- osteoblasts, but not TRIF-/- macrophages. LPS and IL-1alpha enhanced the survival of TRIF-/- osteoclasts, but not MyD88-/- osteoclasts. Diacyl lipopeptide did not support the survival of osteoclasts because of the lack of Toll-like receptor (TLR)6 in osteoclasts. Macrophages expressed both TRIF and TRIF-related adaptor molecule (TRAM) mRNA, whereas osteoblasts and osteoclasts expressed only TRIF mRNA. Bone histomorphometry showed that MyD88-/- mice exhibited osteopenia with reduced bone resorption and formation. These results suggest that the MyD88-mediated signal is essential for the osteoclastogenesis and function induced by IL-1 and TLR ligands, and that MyD88 is physiologically involved in bone turnover.
Adaptor Proteins, Signal Transducing↗
Suppression of osteoprotegerin expression by prostaglandin E2 is crucially involved in lipopolysaccharide-induced osteoclast formation.
LPS is a potent stimulator of bone resorption in inflammatory diseases. The mechanism by which LPS induces osteoclastogenesis was studied in cocultures of mouse osteoblasts and bone marrow cells. LPS stimulated osteoclast formation and PGE(2) production in cocultures of mouse osteoblasts and bone marrow cells, and the stimulation was completely inhibited by NS398, a cyclooxygenase-2 inhibitor. Osteoblasts, but not bone marrow cells, produced PGE(2) in response to LPS. LPS-induced osteoclast formation was also inhibited by osteoprotegerin (OPG), a decoy receptor of receptor activator of NF-kappaB ligand (RANKL), but not by anti-mouse TNFR1 Ab or IL-1 receptor antagonist. LPS induced both stimulation of RANKL mRNA expression and inhibition of OPG mRNA expression in osteoblasts. NS398 blocked LPS-induced down-regulation of OPG mRNA expression, but not LPS-induced up-regulation of RANKL mRNA expression, suggesting that down-regulation of OPG expression by PGE(2) is involved in LPS-induced osteoclast formation in the cocultures. NS398 failed to inhibit LPS-induced osteoclastogenesis in cocultures containing OPG knockout mouse-derived osteoblasts. IL-1 also stimulated PGE(2) production in osteoblasts and osteoclast formation in the cocultures, and the stimulation was inhibited by NS398. As seen with LPS, NS398 failed to inhibit IL-1-induced osteoclast formation in cocultures with OPG-deficient osteoblasts. These results suggest that IL-1 as well as LPS stimulates osteoclastogenesis through two parallel events: direct enhancement of RANKL expression and suppression of OPG expression, which is mediated by PGE(2) production.
Animals↗
Qualitative investigation on hydrothermal treatment of Hinoki (Chamaecyparis obtusa) bark for production of useful chemicals.
Hydrothermal treatment of an outer layer of a bark of Hinoki (Chamaecyparis obtusa) tree was investigated qualitatively for the possibility of utilizing residual forest biomass to produce valuable chemicals. Experiments were carried out in a semibatch reactor apparatus that allows the study of the effect of reaction temperatures in a single run. Gas chromatography-mass spectrometry analyses show the presence of useful chemicals such as furfural, aromatic compounds (1,3-di-tert-butyl benzene and 2,4-di-tert-butyl phenol), and fatty acids (myristic acid, palmitic acid, and stearic acid) in the products.
Benzene Derivatives↗
p38 Mitogen-activated protein kinase is crucially involved in osteoclast differentiation but not in cytokine production, phagocytosis, or dendritic cell differentiation of bone marrow macrophages.
We previously reported that p38 MAPK signaling is required for osteoclast differentiation but not osteoclast function. Here we further investigated the role of p38 MAPK in the function and differentiation of mouse bone marrow macrophages (BMM phi), common precursors of osteoclasts and dendritic cells. Lipopolysaccharide (LPS) activated the p38 MAPK signaling pathway in BMM phi by sequential phosphorylation of MAPK kinase 3/6, p38 MAPK, and activating transcription factor-2. Treatment of BMM phi with SB203580, a p38 MAPK inhibitor, suppressed LPS-induced phosphorylation of activating transcription factor-2. LPS stimulated production of IL-1 beta, TNF alpha, and IL-6 in BMM phi, and SB203580 failed to inhibit the LPS-induced cytokine production. BMM phi incorporated latex beads via phagocytosis, and SB203580 had no effect on this phagocytosis. BMM phi differentiated into dendritic cells when treated with granulocyte macrophage colony-stimulating factor together with CD40 ligand, TNF alpha, or LPS, and SB203580 failed to inhibit this differentiation. Thus, p38 MAPK-mediated signals are not involved in either BMM phi function or BMM phi differentiation into dendritic cells. The differentiation of BMM phi into osteoclasts in response to receptor activator of nuclear factor-kappa B ligand or TNF alpha was strongly inhibited by SB203580. These findings emphasize the crucial roles of p38 MAPK-mediated signaling in osteoclast differentiation.
Animals↗
Detection of bone metastases in routine follow-up after treatment for primary breast cancer.
BACKGROUND AND OBJECTIVES: The effect of follow-up after primary treatment for breast cancer on overall survival remains highly questionable, and controversy still exists regarding the benefits of regular follow-up. We therefore attempted to assess the role of intensive follow-up in patients with bone metastases. METHODS: We analyzed the survival of 87 breast cancer patients who relapsed first in bone diagnosed either with or without symptoms, from 1985 to 1998. Overall survival (OS) was the main outcome. Recurrence was coded as either asymptomatic, elevated tumor marker, or symptomatic. RESULTS: The median disease free interval was 33 months in the asymptomatic group, 42 months in the elevated tumor marker group, and 43 months in the symptomatic group. Overall survival did not differ significantly between the groups. The median OS was 77 months in the asymptomatic group, 78 months in the elevated tumor marker group, and 79 months in the symptomatic group. CONCLUSIONS: Our study showed that intensive testing, including assessment of serum tumor markers and bone scans, did not improve OS. The results of our study supported the American Society of Clinical Oncology (ASCO) recommendations that routine use of bone scans is not recommended.
Biomarkers, Tumor↗
Value of Three-Dimensional Helical CT Image-Guided Planning for Made-to-Order Lumpectomy in Breast Cancer Patients.
The authors reviewed Niigata Cancer Center Hospital's experience treating patients with lumpectomy to evaluate the utility of three-dimensional helical computed tomography (3D-CT) image-guided made-to-order lumpectomy and determine a positive margin rate. From April 1993 to September 2000, 251 breasts in 248 patients were treated with lumpectomy with a 1 cm macroscopic free margin. In 213 breasts (85%), 3D-CT image-guided made-to-order lumpectomy was performed. Thirty-eight breasts (15%) underwent a lumpectomy without 3D-CT. The lumpectomy specimen was sectioned at 5 mm intervals. Margin status was classified as negative (no invasive or ductal carcinoma in situ (DCIS) within 2 mm from the cut surface) or positive. Positive margins were classified as focally positive (invasive or DCIS transected at the margin within 5 mm or one slide) or massively positive. With 3D-CT image-guided lumpectomy, 21% (45/213) of lesions had a positive margin and 42% (16/38) of lesions without 3D-CT image-guided lumpectomy had a positive margin (p = 0.0055). For lesions with massively positive margins, the rates were 9% (4/45) for 3D-CT image-guided lumpectomy and 38% (6/16) for lumpectomy without 3D-CT (p = 0.0152). 3D-CT image-guided made-to-order lumpectomy decreased the positive surgical margin rate. Among patients with positive margins, those with 3D-CT image-guided lumpectomy have less residual cancer than those without 3D-CT.
Adult↗