Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020437 (hypercalcemia)
 10,293 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Humoral hypercalcemia of malignancy (HHM) is at least partly caused by tumor secretion of PTH-related peptide (PTHrP), but there is growing evidence for cosecretion with PTHrP of other bone-resorbing peptides, such as the cytokine interleukin-1 alpha (IL-1 alpha). Administration of PTHrP in vivo and in vitro generally mimics the actions of PTH itself, with increases in both resorption and formation of bone. However, bone in HHM is characterized by uncoupling of bone turnover, with increased resorption and decreased formation. We performed experiments to determine whether IL-1 alpha might alter the effects of PTHrP and produce uncoupling. Thus, we administered to 100-g male rats by sc osmotic minipumps synthetic PTHrP-(1-34) alone (2 micrograms/100 g/day), recombinant IL-1 alpha alone (1.5 micrograms/100 g/day), both peptides together at the previous doses, or vehicle only. We infused 5 groups of 12 rats each (PTHrP, IL-1 alpha, PTHrP plus IL-1 alpha, ad libitum fed control, and controls pair-fed to the PTHrP plus IL-1 alpha group) for 14 days. At the end of the study, blood and urine were taken for chemical measurements, and tibias and femurs were harvested for histomorphometry and extraction of RNA from periosteal cells. As expected, PTHrP induced hypercalcemia, relative hypophosphatemia, phosphaturia, and reduced bone mass. Osteoblast number was increased, but osteoclast number was not. Indices of bone formation were unchanged or reduced. The dose of IL-1 alpha chosen had no statistically significant effect, except for reduced longitudinal bone growth, but when combined with PTHrP, IL-1 alpha reduced hypercalcemia, hypophosphatemia, and phosphaturia. In contrast to the blood and urine effects, IL-1 alpha did not interact significantly with PTHrP's effect on bone measurements. Northern analysis of periosteal cell mRNA showed that PTHrP reduced expression of osteocalcin, but not glyceraldehyde-3-phosphate dehydrogenase; IL-1 alpha had no additional effect. These data suggest that 1) continuously administered PTHrP alone may induce uncoupled bone turnover with decreased cortical bone formation; 2) IL-1 alpha appears to inhibit strongly the renal effects of PTHrP and weakly (if at all) its actions on bone and, thus, to decrease its hypercalcemic, phosphaturic, and hypophosphatemic actions; and 3) cosecretion of IL-1 alpha, and possibly other peptide cytokines, with PTHrP may modify the clinical expression of HHM.
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PMID:Inhibition by human interleukin-1 alpha of parathyroid hormone-related peptide effects on renal calcium and phosphorus metabolism in the rat. 131 27

Topical vitamin D analogues offer a new, effective, more convenient and generally well-tolerated option for the treatment of psoriasis. Only psoriasis vulgaris has been intensively studied, but other forms of the disease may also respond. Both calcitriol and calcipotriol have been shown to be effective in numerous clinical trials, and the latter has compared well with betamethasone valerate and short-contact dithranol in controlled studies. Their mechanism of action is not yet fully understood and may prove complex. The most important effect may be a direct regulation of keratinocyte proliferation and differentiation. However, these compounds also have potent immunological properties, and may act by inhibition of cytokine production by keratinocytes or lymphocytes. Topical application of vitamin D analogues appears generally to be remarkably safe, but hypercalcaemia and hypercalciuria may develop if large quantities are used.
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PMID:Vitamin D analogues and psoriasis. 139 Jan 59

Tumour necrosis factor (TNF) is a pleiotropic cytokine with activities that extend beyond its antitumour effect. There is now increasing evidence that TNF can be either constitutively produced or induced in human tumours. Tumour cells may also lead to TNF induction in normal cells. Experimental studies implicate TNF in processes that contribute to cancer progression. These range from stimulation of cancer growth and metastasis, to metabolic and haematological disturbances, e.g. cancer cachexia, anaemia, and hypercalcaemia. Future cancer therapies may therefore involve neutralisation of TNF activity in cancer patients.
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PMID:Tumour necrosis factor: roles in cancer pathophysiology. 164 92

Murine gamma-interferon (MuIFN-gamma) is a potent inhibitor of bone resorption induced by interleukin 1 and parathyroid hormone-related protein in vitro. To investigate whether MuIFN-gamma is also effective in vivo, the cytokine was injected s.c. into hypercalcemic, tumor (EC-GI)-bearing nude mice, in which parathyroid hormone-related protein and interleukin 1 alpha are synergistically responsible for causing humoral hypercalcemia. When MuIFN-gamma was injected s.c. at a dose of 1 to 20 x 10(4) units for 5 days consecutively, serum calcium concentrations in the tumor-bearing mice decreased in a dose-dependent manner. The minimal effective dose was 5 x 10(4) units/mouse. Unlike calcitonin, which decreased the serum calcium concentration for only 1 to 2 days despite continuous daily injections, MuIFN-gamma decreased it for more than 7 days even after the injections had been stopped. Human gamma-interferon was completely ineffective. The decrease in serum calcium concentration was accompanied by a decrease in urinary calcium excretion. Histological examination of the femur revealed a decreased number of osteoclasts in the MuIFN-gamma-treated mice. Furthermore, MuIFN-gamma, when injected into nude mice or normal mice at a dose of 15 x 10(4) units for 3 days, almost completely abolished the formation of multinucleated osteoclast-like cells in vitro. These findings suggest that MuIFN-gamma suppresses the formation and maturation of osteoclasts and inhibits osteoclastic bone resorption, resulting in the prolonged decrease of serum calcium concentration seen in hypercalcemic, tumor-bearing nude mice. Therefore, bone resorption inhibitors like MuIFN-gamma, which ameliorate humoral hypercalcemia without an escape phenomenon, are potentially useful for the treatment of malignancy-associated hypercalcemia.
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PMID:Prolonged decrease of serum calcium concentration by murine gamma-interferon in hypercalcemic, human tumor (EC-GI)-bearing nude mice. 172 16

The human T-cell lymphotropic virus type I (HTLV-I) is capable of inducing a variety of host cellular genes including many of the cytokines responsible for immune regulation and osteoclast activation. This derangement in cytokine expression may contribute to the panoply of disease states associated with HTLV-I infection such as the adult T-cell leukemia (ATL) and HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). We wished to determine if there was a correlation between the expression of an array of cytokines and the diverse clinical manifestations of ATL and HAM/TSP. Utilizing the techniques of specific mRNA amplification by the polymerase chain reaction (PCR) as well as Northern blotting, we analyzed the ex vivo mRNA expression of gamma-interferon (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and transforming growth factor-beta 1 (TGF-beta 1) in the peripheral blood of HAM/TSP and ATL patients as well as asymptomatic seropositive carriers. IFN-gamma, TNF-alpha, and IL-1 beta transcripts were up-regulated in patients with HAM/TSP and seropositive carriers when compared to their levels in ATL and normal controls. In contrast, the ATL patients constitutively expressed higher levels of TGF-beta 1 mRNA than HAM/TSP and seropositive carriers. In addition, TNF-alpha and IL-1 beta serum levels were elevated in HAM/TSP, but not in ATL patients nor seropositive carriers. However, the circulating leukemic cells from ATL patients secreted increased levels of TGF-beta 1 protein into the culture medium than T-cells derived from HAM/TSP patients. Collectively these results suggest that induction of IFN-gamma, TNF-alpha, and IL-1 beta in HAM/TSP may initiate an inflammatory cascade with subsequent events leading to immune mediated destruction of the central nervous system in these patients. Expression of osteoclast activators such as TNF-alpha and IL-1 beta is not associated with hypercalcemia in ATL. Finally, impaired cellular and humoral immune responses present in ATL, but not in HAM/TSP, may be related to elevated levels of TGF-beta 1 produced by the leukemic cells. These differences in retroviral-induced host cytokine expression in ATL and HAM/TSP suggest alternate roles in disease pathogenesis.
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PMID:Cytokine induction in HTLV-I associated myelopathy and adult T-cell leukemia: alternate molecular mechanisms underlying retroviral pathogenesis. 175 74

When bone-marrow cells from patients with multiple myeloma (MM) were seeded in short-term cultures, a spontaneous proliferation of the myeloma cells occurred for most of the patients with active disease and proliferating myeloma cells in vivo. In all cases, this spontaneous proliferation was inhibited by anti-IL-6 monoclonal antibodies (mabs). Moreover, myeloma cell lines, completely dependent upon exogenous IL-6 for their growth, could be reproducibly established by initially stimulating the myeloma cells with both IL-6 and GM-CSF. These results demonstrate that IL-6 is a major paracrine myeloma-cell growth factor in vitro. High serum IL-6 levels were observed in MM patients with active disease, especially patients with terminal disease. High IL-6 mRNA levels were found in bone-marrow cells of MM patients, mainly in myeloid and monocytic cells, in vivo. The myeloma cells did not express IL-6 mRNA. Injection of anti-IL-6 mabs to MM patients with terminal disease and extramedullary proliferation, completely blocked the myeloma-cell proliferation in vivo and completely inhibited the serum IL-6 bioactivity and the serum CRP levels. One patient with plasma cell leukemia and hypercalcemia was treated for two months with anti-IL-6 mabs and maintain in remission for 2 months without major side effects. Interestingly, the serum calcium levels also decreased in these patients. All these results show that IL-6 is the main cytokine responsible not only for the myeloma-cell proliferation in vivo, but presumably also for the large bone resorption processes observed in human MM.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interleukin-6 is the central tumor growth factor in vitro and in vivo in multiple myeloma. 210 41

In the human granulomatous disease sarcoidosis hypercalcemia and/or hypercalciuria result from the endogenous overproduction of 1,25-dihydroxyvitamin D [1,25-(OH)2D] by the disease-activated macrophage. Unlike the renal 25-hydroxy-vitamin D (25OHD)-1-hydroxylase, normally the sole synthetic source of the hormone in man, the 25OHD3-1-hydroxylation reaction in cultured pulmonary alveolar macrophages (PAM) from patients with sarcoidosis is subject to stimulation by the immune cytokine interferon-gamma (IFN gamma) and inhibition by the antiinflammatory glucocorticoid dexamethasone. The data presented here suggest that IFN gamma and calcium ionophore A23187 promote enhanced expression of the sarcoid PAM 25OHD3-1-hydroxylation reaction by increasing endogenous arachidonic acid metabolism through the 5-lipoxygenase pathway. Dexamethasone, an inhibitor of the cellular phospholipase-A2-arachidonic acid-generating system, and BW755C, a lipoxygenase pathway inhibitor, inhibited PAM 1,25-(OH)2D3 synthesis by 64% and 54%, respectively. Conversely, leukotriene C4, a distal metabolite in the arachidonic acid 5-lipoxygenase pathway, increased the hydroxylation reaction by 234% and restored dexamethasone-inhibited PAM 1,25-(OH)2D3 synthetic activity. The results of this study provide presumptive evidence for an important role of agonist (IFN gamma)-calcium-modulated eicosanoid metabolism in the regulated synthesis of 1,25-(OH)2D by PAM in sarcoidosis.
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PMID:A role for endogenous arachidonate metabolites in the regulated expression of the 25-hydroxyvitamin D-1-hydroxylation reaction in cultured alveolar macrophages from patients with sarcoidosis. 210 25

To investigate the mechanism of the inhibitory effects of interferon-gamma (IFN-gamma) on bone resorption, the effects of murine IFN-gamma on 45Ca release from prelabeled fetal mouse forearm bones were investigated. Murine IFN-gamma usually did not affect basal 45Ca release but almost completely and equipotently inhibited bone resorption induced by PTH(1-34), PTH-rP(1-34), 1,25(OH)2D3, and interleukin 1 (IL-1). The half-maximal concentration for inhibition of bone resorption induced by IL-1 alpha was 25.8 +/- 14.6 U/ml (mean +/- SD for 13 experiments), which is not different from those for PTH, PTH-rP, and 1,25(OH)2D3. There was no correlation between prostaglandin E2 concentration in the conditioned medium and 45Ca release from the IFN-gamma-treated forearm bones. The inhibitory effect of IFN-gamma on bone resorption induced by PTH-rP (1-34) or IL-1 alpha continued during 6 days of culture, whereas that of calcitonin disappeared after 2 days of culture. These findings suggest that IFN-gamma non-preferentially inhibits bone resorption induced by various bone-resorbing factors in fetal mouse forearm bones via a PGE2-independent mechanism. As no escape phenomenon developed in IFN-gamma-treated bones, the cytokine may be potentially useful for treatment of certain patients with malignancy-associated hypercalcemia.
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PMID:Prolonged and ubiquitous inhibition by interferon gamma of bone resorption induced by parathyroid hormone-related protein, 1,25-dihydroxyvitamin D3, and interleukin 1 in fetal mouse forearm bones. 212 24

It has long been known that complex interactions occur between tumors and normal host immune cells. The human melanoma cell line A375 has been used previously as an indicator cell for tumor cell cytotoxicity mediated by monocytes. During other studies on this tumor cell line, we noted that the conditioned media harvested from A375 cultures induced both the human monocytoid cell line U937 and human blood monocytes to release the cytokine tumor necrosis factor (TNF). We characterized this tumor factor which induced TNF release by monocytic cells. Purification was performed using ammonium sulfate precipitation, ion exchange (DEAE) chromatography, gel filtration, and reversed-phase high performance liquid chromatography. The factor copurified with granulocyte-macrophage colony-stimulating factor (GM-CSF). The purified material caused the release of TNF by U937 cells and stimulated formation of granulocyte-macrophage colonies in methyl cellulose. TNF release by U937 cells in response to A375-conditioned medium was inhibited by neutralizing antibodies to GM-CSF. The TNF-inducing activity in A375-conditioned medium was completely removed by an anti-GM-CSF affinity column. Western blotting using antibodies to GM-CSF confirmed a single Mr27,000 band in A375-conditioned medium. We found that recombinant human GM-CSF stimulated TNF production by the same cells as the tumor-conditioned medium. These data show that A375 human melanoma cells produce GM-CSF, which in turn causes TNF production by cells in the monocyte lineage. The combination of GM-CSF production by the tumor and TNF production by immune cells may influence not only tumor growth but also some of the paraneoplastic syndromes associated with malignancy such as hypercalcemia, cachexia and leukocytosis.
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PMID:Stimulation of tumor necrosis factor release from monocytic cells by the A375 human melanoma via granulocyte-macrophage colony-stimulating factor. 218 30

Autonomous production of cytokines such as the hematopoietic colony-stimulating factors (CSFs), IL-1, or IL-6 has been demonstrated in numerous human and murine neoplasms, and may be involved in the pathogenesis of several paraneoplastic syndromes such as leukocytosis, fever, and hypercalcemia. Because of the high frequency with which mutations in ras protooncogenes have been detected in human tumors, as well as evidence linking ras gene products to activation of certain cellular functions, we investigated whether ras mutations might influence the regulation of cytokine genes. Normal human fibroblasts transfected with a mutant val12 H-ras oncogene expressed increased levels of mRNA transcripts encoding granulocyte-CSF (G-CSF), granulocyte-macrophage-CSF (GM-CSF), and IL-1 beta compared with controls. Human mesothelioma cells transfected with a mutant asp12 N-ras oncogene exhibited similar alterations in cytokine gene expression. Estimates of transcriptional activity by nuclear run-on analysis revealed a selective increase in transcription only for the IL-1 gene. Analysis of mRNA half-life demonstrated a marked increase in the stability of numerous cytokine transcripts, including G-CSF, GM-CSF, IL-1, and IL-6. The addition of anti-IL-1 neutralizing antibody to cultures of cells expressing ras mutants did not block the expression of any of the cytokines examined, suggesting that the baseline expression of GM-CSF, G-CSF, and IL-6 was not a secondary event due to the increased transcription of IL-1. These results indicate that mutations in ras genes may alter expression of several cytokine genes through both transcriptional and posttranscriptional mechanisms.
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PMID:Expression of ras oncogenes in cultured human cells alters the transcriptional and posttranscriptional regulation of cytokine genes. 221 10


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