RESUMO
Parathyroid hormone-related protein (PTHrP) is a causative factor of humoral hypercalcemia in malignancy. However, it is difficult to explain the mechanism of anorexia/cachexia with PTHrP secretion in detail. Previously, we demonstrated that the expressions of orexigenic peptides increased and anorexigenic peptides decreased under cachectic conditions in rats carrying tumors secreting PTHrP. In this study, we investigated whether such changes in the expression of hypothalamic feeding-regulating peptides can be solely attributed to PTHrP or are a general response under cachectic conditions. Cachectic syndromes were induced in rats by: (i) inoculation of human lung cancer LC-6 cells that secreted PTHrP, (ii) inoculation of human melanoma SEKI cells that secrete not PTHrP but LIF1, (iii) injection of heat-killed Mycobacterium leading to arthritis (AA) and (iv) oral administration of a high dose of 1α,25(OH)(2)D(3) that resulted in hypercalcemia. The LC-6-bearing rats and AA rats were treated with or without anti-PTHrP antibody and indomethacin, respectively, and the expression of the hypothalamic feeding-regulating peptide mRNAs were examined by in situ hybridization histochemistry. The orexigenic peptide mRNAs, such as neuropeptide Y and agouti-related protein, were significantly increased, and that of anorexigenic peptide mRNAs, such as proopiomelanocortin, cocaine- and amphetamine-regulated transcript and corticotropin-releasing hormone were significantly decreased when they developed cachectic syndromes and AA. A high dose of 1α,25(OH)(2)D(3) caused hypercalcemia and body weight loss but did not affect the expression of hypothalamic feeding-regulating peptide mRNAs. The expressions of the hypothalamic feeding-regulating peptides change commonly in different chronic cachectic models without relating to serum calcium levels.
Assuntos
Artrite Experimental/metabolismo , Caquexia/metabolismo , Hipotálamo/metabolismo , Leptina/sangue , Fator Inibidor de Leucemia/metabolismo , Neoplasias Experimentais/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Proteína Relacionada com Agouti/biossíntese , Animais , Artrite Experimental/complicações , Linhagem Celular Tumoral , Hormônio Liberador da Corticotropina/biossíntese , Humanos , Hipercalcemia/etiologia , Hibridização In Situ , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Neoplasias Experimentais/complicações , Proteínas do Tecido Nervoso/biossíntese , Neuropeptídeo Y/biossíntese , Neuropeptídeos/biossíntese , Orexinas , Pró-Opiomelanocortina/biossíntese , RNA Mensageiro/análise , Ratos , Ratos Nus , Ratos WistarRESUMO
BACKGROUND: Skeletal metastases are often accompanied by bone pain. To investigate the clinical meaning of bone pain associated with skeletal metastasis in breast cancer patients after surgery, we explored whether the presence of bone pain was due to skeletal-related events (SREs) or survival (cause specific death, CSD), retrospectively. METHODS: Consecutive breast cancer patients undergoing surgery between 1988 and 1998 were examined for signs of skeletal metastasis until December 2006. Patients who were diagnosed as having skeletal metastasis were the subjects of this study. Bone scans were performed annually for 5, 7 or 10 years; they were also conducted if skeletal metastasis was suspected. Data concerning bone pain and tumor markers at the time of skeletal metastasis diagnosis, and data relating to various factors including tumors, lymph nodes and hormone receptors at the time of surgery, were investigated. The relationships between factors such as bone pain, SRE and CSD were analyzed using the Kaplan-Meier method and Cox's analysis. RESULTS: Skeletal metastasis occurred in 668 patients but the pain status of two patients was unknown, therefore 666 patients were included in the study. At the time of skeletal metastasis diagnosis 270 patients complained of pain; however, 396 patients did not. Analysis of data using Cox's and Kaplan-Meier methods demonstrated that patients without pain had fewer SREs and better survival rates than those with pain. Hazard ratios regarding SRE (base = patients without pain) were 2.331 in univariate analysis and 2.243 in multivariate analysis. Hazard ratios regarding CSD (base = patients without pain) were 1.441 in univariate analysis and 1.535 in multivariate analysis. Similar results were obtained when analyses were carried out using the date of surgery as the starting point. CONCLUSION: Bone pain at diagnosis of skeletal metastasis was an indicator of increased SRE and CSD. However, these data did not support recommendations of follow-up bone surveys in breast cancer patients.
Assuntos
Neoplasias Ósseas/diagnóstico , Neoplasias Ósseas/secundário , Neoplasias da Mama/complicações , Neoplasias da Mama/cirurgia , Dor/mortalidade , Adulto , Idoso , Conservadores da Densidade Óssea/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Neoplasias da Mama/patologia , Estudos de Coortes , Difosfonatos/uso terapêutico , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Dor/tratamento farmacológico , Dor/etiologia , Período Pós-Operatório , Prognóstico , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
We investigated the roles of interleukin-6 (IL-6) and parathyroid hormone-related peptide (PTHrP) in oral squamous cell carcinoma (OSCC)-induced osteoclast formation. Microarray analyses performed on 43 human OSCC specimens revealed that many of the specimens overexpressed PTHrP mRNA, but a few overexpressed IL-6 mRNA. Immunohistochemical analysis revealed that IL-6 was expressed not only in cancer cells but also in fibroblasts and osteoclasts at the tumor-bone interface. Many of the IL-6-positive cells coexpressed vimentin. Conditioned medium (CM) derived from the culture of oral cancer cell lines (BHY, Ca9-22, HSC3, and HO1-u-1) stimulated Rankl expression in stromal cells and osteoclast formation. Antibodies against both human PTHrP and mouse IL-6 receptor suppressed Rankl in ST2 cells and osteoclast formation induced by CM from BHY and Ca9-22, although the inhibitory effects of IL6 antibody were greater than those of PTHrP antibody. CM derived from all of the OSCC cell lines effectively induced IL-6 expression in stromal cells, and the induction was partially blocked by anti-PTHrP antibody. Xenografts of HSC3 cells onto the periosteal region of the parietal bone in athymic mice presented histology and expression profiles of RANKL and IL-6 similar to those observed in bone-invasive human OSCC specimens. These results indicate that OSCC provides a suitable microenvironment for osteoclast formation not only by producing IL-6 and PTHrP but also by stimulating stromal cells to synthesize IL-6.
Assuntos
Carcinoma de Células Escamosas/fisiopatologia , Diferenciação Celular/genética , Interleucina-6/fisiologia , Neoplasias Bucais/fisiopatologia , Osteoclastos/fisiologia , Proteína Relacionada ao Hormônio Paratireóideo/fisiologia , Células Estromais/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/secundário , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Interleucina-6/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Pessoa de Meia-Idade , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Osteoclastos/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/genética , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/farmacologia , Células Estromais/efeitos dos fármacos , Células Estromais/patologia , Transplante HeterólogoRESUMO
Angiogenesis plays a crucial role in cancer progression and metastasis. Thus, blocking tumor angiogenesis is potentially a universal approach to prevent tumor establishment and metastasis. In this study, we used in vivo and ex vivo fluorescence imaging to show that an antihuman vascular endothelial growth factor (VEGF) antibody represses angiogenesis and the growth of primary tumors of human fibrosarcoma HT1080 cells in implanted nude mice. Interestingly, administering the antihuman VEGF antibody reduced the development of new blood vessels and normalized pre-existing tumor vasculature in HT1080 cell tumors. In addition, antihuman VEGF antibody treatment decreased lung metastasis from the primary tumor, whereas it failed to block lung metastasis in a lung colonization experiment in which tumor cells were injected into the tail vein. These results suggest that VEGF produced by primary HT1080 cell tumors has a crucial effect on lung metastasis. The present study indicates that the in vivo fluorescent microscopy system will be useful to investigate the biology of angiogenesis and test the effectiveness of angiogenesis inhibitors.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Fibrossarcoma/irrigação sanguínea , Neovascularização Patológica/prevenção & controle , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Fibrossarcoma/patologia , Fibrossarcoma/secundário , Fibrossarcoma/terapia , Fluorescência , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Metástase Neoplásica/prevenção & controle , Fator A de Crescimento do Endotélio Vascular/fisiologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
It has been shown that in the mouse colon 26 tumor model, tumors grown in the subcutis (subcutis colon 26) caused early onset of cachectic syndromes, whereas those in the liver (liver colon 26) did not. Both interleukin (IL)-6 and parathyroid hormone-related protein (PTHrP) were involved in the development of cachectic syndromes in this tumor model. However, whether expression of PTHrP and IL-6 is differently regulated in the tumor microenvironment is unclear. In the present study, culturing the colon 26 cells under different conditions in vitro revealed that IL-6 production was increased by monolayer culture under a low-glucose condition but not by spheroid culture. In contrast, PTHrP production was increased by spheroid culture but not by monolayer culture, even under a low-glucose condition. Gene expression profiling revealed that the expression of cyclooxygenase (COX)-2 was up-regulated in both subcutis colon 26 and spheroid cultures, and that COX-2 inhibitor NS-398 suppressed PTHrP production in spheroid cultures. Furthermore, administration of NS-398 decreased the PTHrP level without affecting the tumor growth in mice bearing subcutis colon 26. These results demonstrate that production of PTHrP and IL-6 largely depends on the microenvironments in which tumors are developed or metastasized and that up-regulation of COX-2 in a necrobiotic environment leads to PTHrP production, thereby causing cachectic syndromes.
Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias do Colo/metabolismo , Ciclo-Oxigenase 2/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Animais , Becaplermina , Caquexia/etiologia , Cálcio/metabolismo , Neoplasias do Colo/patologia , Inibidores de Ciclo-Oxigenase/farmacologia , Perfilação da Expressão Gênica , Glucose/metabolismo , Humanos , Interleucina-6/metabolismo , Masculino , Camundongos , Necrose , Nitrobenzenos/farmacologia , Análise de Sequência com Séries de Oligonucleotídeos , Fator de Crescimento Derivado de Plaquetas/metabolismo , Proteínas Proto-Oncogênicas c-sis , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulfonamidas/farmacologia , Células Tumorais CultivadasAssuntos
Calcitriol/fisiologia , Distúrbios do Metabolismo do Cálcio/etiologia , Fatores de Crescimento de Fibroblastos/fisiologia , Hormônio Paratireóideo/fisiologia , Distúrbios do Metabolismo do Fósforo/etiologia , Receptores de Detecção de Cálcio/fisiologia , Animais , Calcitonina/fisiologia , Fator de Crescimento de Fibroblastos 23 , Glucuronidase/fisiologia , Humanos , Proteínas Klotho , Mutação , Hormônio Paratireóideo/genética , Proteína Relacionada ao Hormônio Paratireóideo/genética , Proteína Relacionada ao Hormônio Paratireóideo/fisiologia , Receptor Tipo 1 de Hormônio Paratireóideo/genética , Receptor Tipo 1 de Hormônio Paratireóideo/fisiologia , Receptores de Detecção de Cálcio/genéticaRESUMO
PURPOSE: Parathyroid hormone-related protein (PTHrP) is a causative factor of humoral hypercalcemia of malignancy (HHM) and concurrent anorexia and wasting. Because changes in the expression of hypothalamic feeding-regulating peptides can directly affect appetites and thereby can cause anorexia and wasting, we addressed whether the cachectic syndromes induced by PTHrP rely on the action of hypothalamic feeding-regulating peptides. EXPERIMENTAL DESIGN: Rats were inoculated with a LC-6 human cancer xenograft that secreted PTHrP, and the mRNA levels of the hypothalamic feeding-regulating peptide genes and serum leptin levels were examined before and after the development of HHM by in situ hybridization histochemistry and ELISA, respectively. Some rats were given the anti-PTHrP antibody. RESULTS AND CONCLUSION: The mRNA levels for the orexigenic peptides, such as the agouti-related protein and the neuropeptide Y in the arcuate nucleus (Arc), were significantly increased after the development of HHM, whereas the mRNA levels for the anorexigenic peptides, such as the proopiomelanocortin in the Arc, the cocaine and amphetamine-regulated transcript in the Arc, and the corticotropin-releasing factor in the paraventricular nucleus, were significantly decreased after the development of HHM. Plasma leptin levels were also reduced in cachectic rats, and the administration of anti-PTHrP antibody to the cachectic rats not only improved the cachectic symptoms but also restored the mRNA levels of these orexigenic and anorexigenic peptides, except for orexin. Thus, PTHrP induces HHM and concurrent cachectic syndromes by mechanisms other than directly modulating the leptin or hypothalamic feeding-regulated peptides.
Assuntos
Caquexia/etiologia , Regulação Neoplásica da Expressão Gênica , Proteína Relacionada ao Hormônio Paratireóideo/fisiologia , Peptídeos/química , Animais , Linhagem Celular Tumoral , Humanos , Hipotálamo/metabolismo , Hibridização In Situ , Leptina/sangue , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Neuropeptídeo Y/metabolismo , Proteína Relacionada ao Hormônio Paratireóideo/metabolismo , Ratos , Ratos NusRESUMO
Transforming growth factor (TGF)-beta signaling has been shown to promote tumor growth and metastasis in advanced cancer. Use of inhibitors of TGF-beta signaling may thus be a novel strategy for treatment of patients with such cancers. In this study, we investigated the effects of a novel TGF-beta type I receptor (TbetaR-I) kinase inhibitor, Ki26894, on bone metastasis of a highly bone-metastatic variant of human breast cancer MDA-MB-231 cells, termed MDA-MB-231-5a-D (MDA-231-D). Ki26894 blocked TGF-beta signaling in MDA-231-D cells, as detected by suppression of phosphorylation of Smad2 and inhibition of TGF-beta-responsive reporter activity. Moreover, Ki26894 decreased the motility and the invasion of MDA-231-D cells induced by TGF-beta in vitro. Ki26894 also suppressed transcription of plasminogen activator inhibitor-1 (PAI-1), parathyroid hormone-related protein (PTHrP), and interleukin-11 (IL-11) mRNA of MDA-231-D cells, which were stimulated by TGF-beta. X-ray radiography revealed that systemic Ki26894 treatment initiated 1 day before the inoculation of MDA-231-D cells into the left ventricle of BALB/cnu/nu female mice resulted in decreased bone metastasis of breast cancer cells. Moreover, Ki26894 prolonged the survival of mice inoculated with MDA-231-D cells compared to vehicle-treated mice. These findings suggest that TbetaR-I kinase inhibitors such as Ki26894 may be useful for blocking the progression of advanced cancers.
Assuntos
Receptores de Ativinas Tipo I/farmacocinética , Antineoplásicos/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Mamárias Experimentais/tratamento farmacológico , Neoplasias Mamárias Experimentais/patologia , Metástase Neoplásica/prevenção & controle , Inibidores de Proteínas Quinases/farmacologia , Receptores de Ativinas Tipo I/efeitos dos fármacos , Animais , Neoplasias Ósseas/secundário , Feminino , Humanos , Immunoblotting , Técnicas In Vitro , Camundongos , Invasividade Neoplásica/prevenção & controle , Proteínas Serina-Treonina Quinases , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptores de Fatores de Crescimento Transformadores beta/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Differentiation of committed osteoblasts is controlled by complex activities involving signal transduction and gene expression, and Runx2 and Osterix function as master regulators for this process. Recently, CCAAT/enhancer-binding proteins (C/EBPs) have been reported to regulate osteogenesis in addition to adipogenesis. However, the roles of C/EBP transcription factors in the control of osteoblast differentiation have yet to be fully elucidated. Here we show that C/EBP homologous protein (CHOP; also known as C/EBPzeta) is expressed in bone as well as in mesenchymal progenitors and primary osteoblasts. Overexpression of CHOP reduces alkaline phosphatase activity in primary osteoblasts and suppresses the formation of calcified bone nodules. CHOP-deficient osteoblasts differentiate more strongly than their wild-type counterparts, suggesting that endogenous CHOP plays an important role in the inhibition of osteoblast differentiation. Furthermore, endogenous CHOP induces differentiation of calvarial osteoblasts upon bone morphogenetic protein (BMP) treatment. CHOP forms heterodimers with C/EBPbeta and inhibits the DNA-binding activity as well as Runx2-binding activity of C/EBPbeta, leading to inhibition of osteocalcin gene transcription. These findings indicate that CHOP acts as a dominant-negative inhibitor of C/EBPbeta and prevents osteoblast differentiation but promotes BMP signaling in a cell-type-dependent manner. Thus, endogenous CHOP may have dual roles in regulating osteoblast differentiation and bone formation.
Assuntos
Adipogenia , Osteoblastos/citologia , Fator de Transcrição CHOP/metabolismo , Células 3T3-L1 , Animais , Proteínas Morfogenéticas Ósseas/farmacologia , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Células COS , Células Cultivadas , Chlorocebus aethiops , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Regulação para Baixo/genética , Perfilação da Expressão Gênica , Camundongos , Modelos Biológicos , Osteocalcina/genética , Osteogênese/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Ligação Proteica , Fator de Transcrição CHOP/genéticaRESUMO
Patients harboring cancer and other tumors frequently exhibit such bone morbidity as metabolic bone diseases and bone metastases. Cancers produce and secrete cytokines and growth factors for their growth and survival. Cytokines are also produced by reacting immune systems. Those humoral factors, when produced in a sizable quantity, enter into the general circulation and become a causative principle for paraneoplastic syndrome. An example is parathyroid hormone-related protein (PTHrP) for humoral hypercalcemia of malignancy, and fibroblast growth factor 23 (FGF23) for oncogenic osteomalacia. In animal models, PTHrP appear to produce cancer-associated cachexia as well. Some particular cancers such as those of lung, prostate, breast and thyroid are prone to metastasize into bone resulting in metastatic bone disease. Interactions between these cancers and inhabitant bone cells and bone matrices constitute a favorable condition where particular cancer cells deposit and survive. A variety of principle factors, mostly signal materials, were identified that are responsible for these interactions and these principle factors can be a target for the development of new chemotherapeutic agents.
Assuntos
Doenças Ósseas Metabólicas/etiologia , Neoplasias Ósseas/secundário , Neoplasias/complicações , Síndromes Paraneoplásicas/etiologia , Animais , Citocinas/metabolismo , Citocinas/fisiologia , Fator de Crescimento de Fibroblastos 23 , Substâncias de Crescimento/metabolismo , Substâncias de Crescimento/fisiologia , Humanos , Neoplasias/metabolismoRESUMO
Although active vitamin D drugs have been used for the treatment of osteoporosis, how the vitamin D receptor (VDR) regulates bone cell function remains largely unknown. Using osteoprotegerin-deficient mice, which exhibit severe osteoporosis due to excessive receptor activator of NF-kappaB ligand/receptor activator of NF-kappaB (RANKL/RANK) stimulation, we show herein that oral treatment of these mice with 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] inhibited bone resorption and prevented bone loss, suggesting that VDR counters RANKL/RANK signaling. In M-CSF-dependent osteoclast precursor cells isolated from mouse bone marrow, 1alpha,25(OH)2D3 potently and dose-dependently inhibited their differentiation into multinucleate osteoclasts induced by RANKL. Among signaling molecules downstream of RANK, 1alpha,25(OH)2D3 inhibited the induction of c-Fos protein after RANKL stimulation, and retroviral expression of c-Fos protein abrogated the suppressive effect of 1alpha,25(OH)2D3 on osteoclast development. By screening vitamin D analogs based on their c-Fos-suppressing activity, we identified a new analog, named DD281, that inhibited bone resorption and prevented bone loss in ovariectomized mice, more potently than 1alpha,25(OH)2D3, with similar levels of calcium absorption. Thus, c-Fos protein is an important target of the skeletal action of VDR-based drugs, and DD281 is a bone-selective analog that may be useful for the treatment of bone diseases with excessive osteoclastic activity.
Assuntos
Conservadores da Densidade Óssea/metabolismo , Calcitriol/análogos & derivados , Calcitriol/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Animais , Conservadores da Densidade Óssea/uso terapêutico , Reabsorção Óssea/prevenção & controle , Calcitriol/uso terapêutico , Proteínas de Transporte/metabolismo , Diferenciação Celular/fisiologia , Feminino , Glicoproteínas/genética , Glicoproteínas/metabolismo , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoporose/tratamento farmacológico , Osteoporose/metabolismo , Osteoprotegerina , Ovariectomia , Proteínas Proto-Oncogênicas c-fos/genética , Ligante RANK , Receptor Ativador de Fator Nuclear kappa-B , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/metabolismo , Transdução de Sinais/fisiologia , Células-Tronco/citologia , Células-Tronco/metabolismoRESUMO
BACKGROUND: Parathyroid hormone-related protein (PTHrP) has been implicated in bone metastasis. However, the effects on bone metastasis of blocking the PTHrP function have not been tested in the clinic. Here, the effects of a humanized anti-PTHrP monoclonal antibody (mAb) on bone metastasis in a human xenograft model are shown. MATERIALS AND METHODS: Subline MDA-5a, with high bone metastatic activity, was established from the human breast cancer cell line MDA-MB-231. Mice were injected with MDA-5a and an anti-PTHrP monoclonal antibody (mAb) raised against human PTHrP (1-34); bone metastasis was evaluated by X-ray photography. RESULTS: MDA-5a produced elevated levels of PTHrP, Interleukin 8 (IL-8), IL-6 and matrix metalloproteinase 1 (MMP-1) and frequently metastasized to the bone. Administration of the humanized anti-PTHrP mAb significantly suppressed osteolytic bone metastasis of MDA-5a and caused osteogenesis at the sites of metastasis. CONCLUSION: The humanized anti-PTHrP mAb was effective against bone metastasis by inducing osteogenesis and, therefore, will provide a new treatment option for bone metastasis in breast cancer.
Assuntos
Anticorpos Monoclonais/farmacologia , Neoplasias Ósseas/prevenção & controle , Neoplasias da Mama/tratamento farmacológico , Proteína Relacionada ao Hormônio Paratireóideo/imunologia , Animais , Anticorpos Monoclonais/imunologia , Neoplasias Ósseas/genética , Neoplasias Ósseas/metabolismo , Neoplasias Ósseas/secundário , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica , Humanos , Interleucinas/biossíntese , Interleucinas/genética , Metaloproteinase 1 da Matriz/biossíntese , Metaloproteinase 1 da Matriz/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Análise de Sequência com Séries de Oligonucleotídeos , Proteína Relacionada ao Hormônio Paratireóideo/biossíntese , Proteína Relacionada ao Hormônio Paratireóideo/genética , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
PURPOSE: Bisphosphonate and calcitonin lower blood calcium in humoral hypercalcemia of malignancy (HHM) by suppressing osteoclastic bone resorption, but repeated administration of these drugs often leads to relapse. In this study, we examined the roles of parathyroid hormone-related protein (PTHrP) in the development of bisphosphonate- and calcitonin-refractory HHM. EXPERIMENTAL DESIGN: Nude rats bearing the LC-6 JCK tumor xenograft (LC-6 rats) exhibited high bone turnover and HHM. Repeated administration of alendronate induced a sustained suppression of the bone resorption, but it caused only early and transient reduction of the blood calcium levels, leading to unresponsiveness to the drug. Because high blood levels of PTHrP were detected in the LC-6 rats, those that developed alendronate-refractory HHM were treated with an anti-PTHrP antibody. RESULTS: Administration of anti-PTHrP antibody to animals that received repeated administration of alendronate, thereby developing alendronate-refractory HHM, resulted in an increase in fractional excretion of calcium and a marked decrease of blood calcium level. Drug-refractory HHM was also observed in animals that received another osteoclast inhibitor, an eel calcitonin analogue elcatonin. The blood calcium level decreased after the initial administration of elcatonin, but it eventually became elevated during repeated administration. Administration of the anti-PTHrP antibody, but not of alendronate, effectively reduced the blood calcium of the animals that developed elcatonin-refractory HHM. CONCLUSION: High levels of circulating PTHrP and the resulting augmentation of renal calcium reabsorption is one of the major causes of the emergence of osteoclast inhibitor-refractory HHM. Thus, blockage of PTHrP functions by a neutralizing antibody against PTHrP would benefit patients who develop bisphosphonate- or calcitonin-refractory HHM.
Assuntos
Alendronato/uso terapêutico , Cálcio/metabolismo , Hipercalcemia/etiologia , Rim/metabolismo , Neoplasias Pulmonares/complicações , Proteína Relacionada ao Hormônio Paratireóideo/fisiologia , Alendronato/administração & dosagem , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Reabsorção Óssea/prevenção & controle , Calcitonina/administração & dosagem , Calcitonina/análogos & derivados , Calcitonina/uso terapêutico , Cálcio/sangue , Cálcio/farmacocinética , Linhagem Celular Tumoral , Difosfonatos/administração & dosagem , Difosfonatos/uso terapêutico , Resistência a Medicamentos , Humanos , Hipercalcemia/tratamento farmacológico , Rim/efeitos dos fármacos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Hormônio Paratireóideo/sangue , Proteína Relacionada ao Hormônio Paratireóideo/sangue , Proteína Relacionada ao Hormônio Paratireóideo/imunologia , Ratos , Ratos Endogâmicos F344 , Ratos Nus , Fatores de Tempo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Nude rats bearing the LC-6-JCK human lung cancer xenograft displayed cancer-associated wasting syndrome in addition to humoral hypercalcemia of malignancy. In these rats, not only PTHrP but also several other human proinflammatory cytokines, such as IL-6, leukemia-inducing factor, IL-8, IL-5 and IL-11, were secreted to the bloodstream. Proinflammatory cytokines induce acute-phase reactions, as evidenced by a decrease of serum albumin and an increase in alpha1-acid glycoprotein. Tumor resection abolished the production of proinflammatory cytokines and improved acute-phase reactions, whereas anti-PTHrP antibody affected neither proinflammatory cytokine production nor acute-phase reactions. Nevertheless, tumor resection and administration of anti-PTHrP antibody similarly and markedly attenuated not only hypercalcemia but also loss of fat, muscle and body weight. Body weight gain by anti-PTHrP antibody was associated with increased food consumption; increased body weight from anti-PTHrP antibody was observed when animals were freely fed but not when they were given the same feeding as those that received only vehicle. Furthermore, nude rats bearing LC-6-JCK showed reduced locomotor activity, less eating and drinking and low blood phosphorus; and anti-PTHrP antibody restored them. Although alendronate, a bisphosphonate drug, decreased blood calcium, it affected neither locomotor activity nor serum phosphorus level. These results indicate that PTHrP represses physical activity and energy metabolism independently of hypercalcemia and proinflammatory cytokine actions and that deregulation of such physiologic activities and functions by PTHrP is at least in part involved in PTHrP-induced wasting syndrome.
Assuntos
Adenocarcinoma/patologia , Carcinoma de Células Escamosas/patologia , Metabolismo Energético , Neoplasias Renais/patologia , Neoplasias Laríngeas/patologia , Neoplasias Pulmonares/patologia , Atividade Motora , Neoplasias Pancreáticas/patologia , Proteína Relacionada ao Hormônio Paratireóideo/fisiologia , Síndrome de Emaciação/fisiopatologia , Adenocarcinoma/veterinária , Animais , Peso Corporal , Carcinoma de Células Escamosas/veterinária , Citocinas/sangue , Citocinas/metabolismo , Modelos Animais de Doenças , Comportamento Alimentar , Humanos , Hipercalcemia/complicações , Hipercalcemia/fisiopatologia , Hipercalcemia/veterinária , Neoplasias Renais/veterinária , Neoplasias Laríngeas/veterinária , Neoplasias Pulmonares/veterinária , Neoplasias Pancreáticas/veterinária , Ratos , Ratos Nus , Transplante Heterólogo , Síndrome de Emaciação/veterináriaRESUMO
Fibroblast growth factor-23 (FGF-23), a novel phosphate-regulating factor, was elevated in hypophosphatemic patients with X-linked hypophosphatemic rickets/osteomalacia and also in patients with chronic kidney disease. These observations suggested the pathophysiological importance of FGF-23 on phosphate homeostasis. However, regulation of FGF-23 production is still unclear. We investigated effects of both dietary phosphorus and 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2)D(3)) on circulating FGF-23 in vivo Administration of. 1alpha,25(OH)(2)D(3) dose-dependently increased serum FGF-23 in thyroparathyroidectomized rats without correlating with serum inorganic phosphorus or serum parathyroid hormone. On the other hand, vitamin D receptor null mice had very low serum FGF-23 and did not respond to the 1alpha,25(OH)(2)D(3) administration. These observations suggested 1alpha,25(OH)(2)D(3) directly or indirectly regulates circulating FGF-23. Serum FGF-23 had a strong correlation with serum inorganic phosphorus controlled by dietary phosphorus in 5/6 nephrectomized rats. High phosphate diet elicited a 5-fold increase in serum FGF-23 compared with sham-operated rats, whereas serum FGF-23 did not correlate with serum calcium or serum creatinine in 5/6 nephrectomized rats. Administration of 1alpha,25-dihydroxyvitamin D(3) also elicited a severalfold increase in serum FGF-23 in the uremic rats. Taken together, this shows that both serum phosphorus and 1alpha,25(OH)(2)D(3) regulate circulating FGF-23 independent of each other. Therefore, we proposed there was a feedback loop existing among serum phosphorus, 1alpha,25(OH)(2)D(3), and FGF-23, in which the novel phosphate-regulating bone-kidney axis integrated with the parathyroid hormone-vitamin D(3) axis in regulating phosphate homeostasis.
Assuntos
Calcitriol/metabolismo , Fatores de Crescimento de Fibroblastos/sangue , Regulação da Expressão Gênica , Fósforo/metabolismo , Ração Animal , Animais , Cálcio/sangue , Creatinina/sangue , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Retroalimentação Fisiológica , Fator de Crescimento de Fibroblastos 23 , Humanos , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Fosfatos/metabolismo , Fósforo/sangue , Ratos , Ratos Sprague-Dawley , Glândula Tireoide/metabolismoRESUMO
A humanized monoclonal antibody against parathyroid hormone-related protein (PTHrP) was generated from the mouse monoclonal antibody raised against the peptide corresponding to the N-terminal 34 amino acids of the human PTHrP [(PTHrP(1-34)]. The humanized antibody interacted with the PTHrP(1-34) with a kD value of 1.90 x 10(-10) M, and the epitope resides between the amino acids 20 and 30 of the PTHrP. PTHrP(1-34) significantly increased the intracellular cAMP levels in the rat osteosarcoma cells that expressed PTHR1, and the 5 microg/mL or higher concentrations of the humanized antibody almost completely blocked the PTHrP-induced cAMP production even in the presence of 2 microg/mL PTHrP(1-34), demonstrating its ability to fully neutralize PTHrP function. There was no significant difference in the potency of the mouse, chimera, or the humanized antibodies to suppress the PTHrP-induced increase in the intracellular cAMP in ROS cells. Furthermore, at the same doses, the administration of the chimera or the humanized antibody was equally effective in reducing the blood ionized calcium levels of hypercalcemic mice bearing the PAN-7-JCK human pancreatic cancer xenograft or the LC-6-JCK human lung cancer xenograft that secreted PTHrP. Thus, humanized anti-PTHrP may be useful for the treatment of the humoral hypercalcemia of malignancy in humans.
Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Hipercalcemia/terapia , Proteína Relacionada ao Hormônio Paratireóideo/antagonistas & inibidores , Proteína Relacionada ao Hormônio Paratireóideo/imunologia , Fragmentos de Peptídeos/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/genética , Linhagem Celular Tumoral , Humanos , Hipercalcemia/sangue , Hipercalcemia/etiologia , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Leves de Imunoglobulina/genética , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/complicações , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Dados de Sequência Molecular , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/complicações , Ratos , Ratos Endogâmicos F344 , Ratos Nus , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/farmacologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Cdc7 expression repressor (CR)/periphilin has been originally cloned as an interactor with periplakin, a precursor of the cornified cell envelope, and suggested to constitute a new type of nuclear matrix. We here show that CR/periphilin is a ubiquitously expressed nuclear protein with speckled distribution. Overexpression of CR/periphilin induces S-phase arrest. Analysis of expression of regulators involved in DNA replication has revealed that both mRNA and protein expression of Cdc7, a regulator of the initiation and continuation of DNA replication, are markedly downregulated by overexpression of CR/periphilin. However, co-expression of Cdc7 only marginally rescues S-phase arrest induced by CR, indicating that CR retards S-phase progression by modifying expression of some genes including Cdc7, which are involved in progression of DNA replication or coordination of DNA replication and S-phase progression.
Assuntos
Proteínas de Ciclo Celular/biossíntese , Regulação para Baixo , Proteínas Nucleares/biossíntese , Proteínas Serina-Treonina Quinases/biossíntese , Fase S , Adenoviridae/genética , Animais , Antígenos de Neoplasias , Northern Blotting , Células COS , Ciclo Celular , Linhagem Celular , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Clonagem Molecular , DNA/metabolismo , DNA Complementar/metabolismo , Etiquetas de Sequências Expressas , Células HeLa , Humanos , Immunoblotting , Imuno-Histoquímica , Imunoprecipitação , Queratinócitos/metabolismo , Modelos Genéticos , Plasmídeos/metabolismo , Reação em Cadeia da Polimerase , Ligação Proteica , Isoformas de Proteínas , RNA Mensageiro/metabolismoRESUMO
The dose-response relationships and the safety of administering 22-oxacalcitriol (OCT) to patients with secondary hyperparathyroidism (2HPT) under regular three-times-weekly hemodialysis (HD) were evaluated by double-blind parallel group design. A total of 203 patients with 2HPT were randomly allocated into four groups, and 5 microg (Group L), 10 microg (Group M), or 15 microg (Group H) OCT, or placebo (Group P) was administrated at the end of every HD for 12 weeks. Reductions of intact-parathyroid hormone (iPTH) concentration greater than 30% from baseline were observed in 7.7% of Group P as compared to 77.3% of the pooled OCT groups after 12 weeks of treatment (Mantel test: P < 0.001). Time-trends (slopes) of log-iPTH concentration calculated by least-squares line fitting to each patient's data during treatment differed between Group P and the pooled OCT groups (t-test: P < 0.001) and these iPTH slopes decreased dose-dependently (linear trend by t-test: P < 0.001). Slopes of serum calcium corrected for albumin (corrected-sCa) concentrations also differed between Group P and the pooled OCT groups (t-test: P < 0.001), and increased dose-dependently (linear trend by t-test: P < 0.0001). Serum phosphorus and Ca x P product increased significantly only in high dose groups. Slopes of log(iPTH) and corrected-sCa concentrations were reciprocally related. Most adverse events were hypercalcemia and dose-related, but occasionally comprised pruritus or increased serum creatinine phosphokinase. These results indicate that OCT produced a strong and dose-dependent suppression of PTH and an increase of corrected-sCa concentration in patients with 2HPT. The recommended initial dosages of OCT would appear to be 5 microg when pretreatment iPTH concentrations are less than 500 pg/mL, and 10 microg when greater than 500 pg/mL for safe and effective treatment. As in the case of PTH, calcium and phosphorus showed dose-dependent increases. It is therefore essential to take precautions as to possible increases in calcium and phosphorus.
Assuntos
Calcitriol/análogos & derivados , Calcitriol/administração & dosagem , Hiperparatireoidismo Secundário/tratamento farmacológico , Fosfatase Ácida/sangue , Idoso , Biomarcadores/sangue , Cálcio/sangue , Relação Dose-Resposta a Droga , Feminino , Humanos , Isoenzimas/sangue , Masculino , Pessoa de Meia-Idade , Fosfatase Ácida Resistente a TartaratoRESUMO
Combined disruption of the ARF gene and the p53 gene causes mouse predisposition to tumors of a wider variety and at a higher frequency than disruption of the p53 gene, indicating that the ARF gene has p53-independent anti-tumor function in addition to p53-dependent function. Coincidentally with this notion, ectopic expression of the p19(ARF) induces apoptosis for wild-type mouse embryo fibroblasts which have been immortalized by introduction of the SV40 virus genome (SV40-MEFs). The protein expression levels of p53, p21(Cip1), and Bax were not upregulated by ectopic expression of p19(ARF) in SV40-MEFs, indicating that expression of p19(ARF) induced apoptosis through p53-independent pathways in this system. Ectopic expression of p19(ARF) induced prominent apoptosis even in SV40-Bak-/-MEFs. In contrast, expression of p19(ARF) induced only a very low grade of apoptosis in Bax-/- or Bax-/-/Bak-/-SV40-MEFs. Remarkable attenuation of p19(ARF)-induced apoptosis by disruption of the Bax gene thus leads to the conclusion that Bax plays a major role in p53-independent apoptosis induced by p19(ARF).