UMLS:C0020437 - FACTA Search

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Query: UMLS:C0020437 (hypercalcemia)
10,293 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hypercalcemia is a common paraneoplastic syndrome. Tumors induce hypercalcemia by a local mechanism associated with the tumor's production of various cytokines increasing bone osteolysis. In addition, many tumors release humoral factors, mainly parathyroid hormone (PTH)-related protein (PTHrP), which stimulates bone resorption and/or tubular calcium reabsorption leading to hypercalcemia. Interaction of PTHrP with other tumor-elaborated cytokines might explain some nonPTH-like features associated with the hypercalcemia of malignancy syndrome. Using assays recognizing various PTHrP epitopes, the majority of hypercalcemic cancer patients have higher immunoreactive PTHrP levels in either plasma or urine than normal subjects. Present data support the concept that PTHrP might also be a factor which promotes tumor growth and also the development of osteolytic metastasis. A variety of therapeutic approaches are available to lower serum calcium in hypercalcemic cancer patients. The pathophysiological mechanisms of hypercalcemia appear to be a determinant of the efficacy of different antihypercalcemic treatments.
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PMID:Hypercalcemia of malignancy--new insights into an old syndrome. 1121 25

The propensity for breast cancer cells to metastasize to bone and to induce osteolysis has long been recognized. Characteristics of both the tumor cells and the bone microenvironment contribute to this phenomenon. The presence of tumor in bone is associated with activation of osteoclasts, resulting in excessive bone resorption and subsequent osteolysis. Breast cancer cells and other tumor types influence osteoclastic bone resorption by increasing the number of osteoclasts and enhancing their resorptive activity. Parathyroid hormone-related peptide, in addition to its role in humorally mediated hypercalcemia, is secreted by metastatic breast cancer cells in bone in which it acts as a paracrine factor to stimulate osteoclasts. As bone matrix is broken down by activated osteoclasts, a rich supply of mitogenic factors is released, including insulin-like growth factors, bone morphogenetic proteins, and fibroblast growth factors. Transforming growth factor (TGF)-beta, one of the most abundant of the bone-derived factors, promotes increased production of parathyroid hormone-related peptide by tumor cells, establishing a "vicious cycle" leading to progressive tumor growth and bone destruction. Bisphosphonates interrupt this cycle by inhibiting osteoclasts, in part by inducing osteoclast apoptosis. In several animal models of breast cancer metastasis to bone, bisphosphonates decrease the number of new bone metastases and inhibit progression of existing lesions. A single 3 microg intravenous injection of zoledronic acid (Zometa; Novartis Pharmaceuticals Corp, East Hanover, NJ), a new highly potent bisphosphonate, prevented destruction of trabecular bone in an orthotopic mouse mammary tumor model. Tumor volume in bone was decreased by zoledronic acid in a dose-dependent manner in the same model, and tumor cell apoptosis was increased by zoledronic acid in bone metastases in the 4T1 murine model of mammary carcinoma metastasis. Zoledronic acid at a dose of 1.0 microg/d for 10 days also reduced bone lesion area in a nude mouse model with existing bone metastases. Although bisphosphonates, including zoledronic acid, are able to induce apoptosis in tumor cells in vitro, studies in animal models to date have generally not shown a reduction in nonosseous tumor. Therefore, bisphosphonate-associated tumor reduction in bone is most likely mediated by osteoclast inhibition or is related to high local concentrations of bisphosphonates in the bone compartment.
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PMID:Preclinical studies with zoledronic acid and other bisphosphonates: impact on the bone microenvironment. 1134 63

Interleukin-6 (IL-6) is a multifunctional cytokine which provides multiple signals on various tissues and cells. In addition, IL-6 is produced by some human renal carcinoma cell lines in vitro and is expressed in a majority of primary renal cell carcinoma (RCC). Serum IL-6 influence the response to immunotherapy. IL-6 appears as a target for rational drug design highly promising for development of new cancer therapies. IL-6 effects are mediated by Stat. Stat (Signal transducers and activators of transcription) signaling pathways represent novel molecular targets for therapeutic implications in metastatic renal cell carcinoma. Inhibitors of Stat signaling pathway will not only block tumor growth by inducing apoptosis, but may also increase the sensitivity of tumors to conventional treatment (immunotherapy). The processes involved in tumor associated angiogenesis should lead to compounds able to interfere with angiogenesis. Il-6 has been implicated in the osteoclastic bone resorption and hypercalcemia associated with metastatic RCC. Different agents were shown to be effective in treating lytic bone disease mediated by osteoclast activation: bisphosphonates and osteoprotegerin.
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PMID:[Interleukin-6 and bone metastasis of renal cancer: molecular bases and therapeutic implications]. 1140 May 11

We report the case of a 34 year old male presenting with symptomatic hypercalcemia due to excessive PTHrP secretion from a pancreatic neuroendocrine carcinoma with extensive hypervascularization and without any evidence for metastatic disease. In the early phase of the disease conventional chemotherapy with streptozocin and doxorubicin was able to control functional activity as well as tumor growth. However, after 2 years tumor escape was indicated by severe therapy-resistant hypercalcemia. Therapeutic options were reduced due to the excessive tumor vascularization and the patient died from his disease after a short period of intensified therapy. The role of PTHrP in hypercalcemia of malignancy (HHM) and its association with neuroendocrine pancreatic tumors as well as possible therapeutic options are reviewed.
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PMID:Pancreatic neuroendocrine tumor with extensive vascularisation and parathyroid hormone-related protein (PTHrP)--associated hypercalcemia of malignancy. 1157 50

The aim of this study is to determine the effects of 1,25(OH)2D3 and its analogues on tumor growth and body weight, changes in plasma ionized calcium, parathyroid hormone-related protein (PTHrP) production, bone resorption, and the distribution of the 1,25(OH)2D3 receptor (VDR) on tumors in nude mice-bearing the canine adenocarcinoma (CAC-8). Thirty-seven nude mice were implanted subcutaneously with CAC-8. Two weeks after implantation, the mice were divided into 5 groups and injected intraperitoneally 3 times/week for 4 weeks with 5 different substrates. Group I (nontumor-bearing mice) were injected with vehicle. Groups II through V were CAC-8-bearing mice injected with the following: Grp. II, vehicle; Grp. III, analog V; Grp. IV, 1,25(OH)2D3; and Grp. V, EB1089. Our results showed that mice body weight (% change) of CAC-8-bearing mice was significantly lower than those of nontumor-bearing mice (p<0.05). CAC-8-bearing mice treated with analog V maintained their body weight better than CAC-8-bearing mice treated with either vehicle, 1,25(OH)2D3, or EB1089. A reduction of tumor growth was observed in CAC-8-bearing mice treated with 1,25(OH)2D3 and its analogues; however, the reduction was not statistically significant compared to the vehicle-treated CAC-8-bearing mice. All CAC-8-bearing mice increased osteoclastic bone resorption and hypercalcemia. Immunohistochemical staining of CAC-8 with VDR antibody demonstrated a positive reaction in nuclei of tumor cells. In conclusion, CAC-8-bearing mice treated with analog V were more active and maintained their body weight better than other CAC-8-bearing groups. Analog V-treated mice also showed no toxic side effects of hypercalcemia despite an increase in plasmaionized calcium comparable to nontumor-bearing mice. Tumor volumes of CAC-8-bearing mice treated with 1,25(OH)2D3 and its analogues were smaller than vehicle-treated CAC-8-bearing mice. This finding suggested an inhibitory effect on tumor cell growth.
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PMID:Effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and its analogues (EB1089 and analog V) on canine adenocarcinoma (CAC-8) in nude mice. 1203 6

Transgenic mouse models of prostate cancer provide unique opportunities to understand the molecular events in prostate carcinogenesis and for the preclinical testing of new therapies. We studied the G gamma T-15 transgenic mouse line, which contains the human fetal globin promoter linked to SV40 T antigen (Tag) and which develops androgen-independent prostate cancer. Using the immunohistochemistry of normal mouse prostates before tumor formation, we showed that the target cells of carcinogenesis in G gamma T-15 mice are located in the basal epithelial layer. We tested the efficacy of the 1,25(OH)(2)D(3) analogue, EB 1089, to chemoprevent prostate cancer in these transgenic mice. Compared with treatment with placebo, treatment with EB 1089 at three different time points before the onset of prostate tumors in mice did not prevent or delay tumor onset. However, EB 1089 significantly inhibited prostate tumor growth. At the highest dose, EB 1089 inhibited prostate tumor growth by 60% (P = 0.0003) and the growth in the number of metastases, although this dose also caused significant hypercalcemia and weight loss. We conducted several in vitro experiments to explore why EB 1089 did not prevent the occurrence of the primary tumors. EB 1089 significantly inhibited the growth of a Tag-expressing human prostate epithelial cell line, BPH-1, and an androgen-insensitive subline of LNCaP cells [which was not inhibited by 1,25(OH)(2)D(3)]. Thus, neither Tag expression nor androgen insensitivity explain the absence of chemopreventive effect. Conversely, neither 1,25(OH)(2)D(3) nor EB 1089 inhibited the growth of the normal rat prostate basal epithelial cell line NRP-152. It is likely that EB 1089 was not effective in delaying the growth of the primary tumor in G gamma T-15 transgenic mice because the target cells of carcinogenesis in these mice are located in the basal epithelial layer. We conclude that G gamma T-15 transgenic mice are a useful model for testing vitamin D-based therapies in androgen-insensitive prostate cancer but are not suitable for studies of vitamin D-based chemoprevention. The superiority of EB 1089 over 1,25(OH)(2)D(3) in the growth suppression of androgen-insensitive prostate cancer cells supports the use of EB 1089 in androgen-insensitive prostate cancer.
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PMID:The G gamma / T-15 transgenic mouse model of androgen-independent prostate cancer: target cells of carcinogenesis and the effect of the vitamin D analogue EB 1089. 1205 97

1,25-dihydroxycholecalciferol [1,25-(OH)2 D3] has been shown to have antiproliferative effects in a wide variety of cancer cell lines. In vivo studies, although often limited by the development of hypercalcemia, have also shown the potential usefulness of 1,25-(OH)2 D3 in inhibiting tumor growth. The potential usefulness of the drug has been hampered by the development of hypercalcemia. This pilot clinical study was designed to evaluate the preclinical results that have shown, locoregional administration of 1,25-(OH)2 D3 in lipiodol can prevent the development of hypercalcemia. Eight patients with refractory HCC were given a single intrahepatic arterial dose (50, 75 or 100 microg) of 1,25-(OH)2 D3 dissolved in 5 ml of lipiodol. Following this, for 4 weeks serum calcium, 1,25-(OH)2 D3, alpha-fetoprotein and a range of biochemical indices were monitored. While, in 3 patients the calcium levels exceeded the normal range, even at these extremely high doses, non of the patients developed grade 3 hypercalcemia. 1,25-(OH)2 D3 administration also led to transient stabilization of serum alpha-fetoprotein in these patients. The data obtained support the hypothesis that, in patients with HCC, locoregional delivery of 1,25-(OH)2 D3 in lipiodol can allow administration of supra-pharmacological doses of the drug without the development of hypercalcemia.
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PMID:Hepatic intra-arterial injection of 1,25-dihydroxyvitamin D3 in lipiodol: Pilot study in patients with hepatocellular carcinoma. 1223 33

PTHrP is the major pathogenetic factor for hypercalcemia in several malignancies including prostate cancer. In the current study, we have assessed the ability of androgens to regulate PTHrP production in androgen-insensitive human prostate cancer cells PC-3 and cells transfected with androgen receptor (PC-3T). Androgen responsiveness caused a marked decrease in PC-3T cell growth, and treatment of these cells with dihydrotestosterone led to inhibition of PTHrP production. These inhibitory effects were readily reversed by androgen receptor antagonist flutamide. To determine the effect of androgens on tumor growth and PTHrP production in vivo, PC-3 and PC-3T cells were injected into the right flank of male BALB/c nu/nu mice. Animals inoculated with PC-3 and PC-3T cells developed palpable tumors at wk 2 and 4, respectively. Inoculation of PC-3T cells into castrated animals resulted in rapid tumor growth in PC-3T tumors, effects that were reversed in PC-3T tumors grown in castrated hosts. Using PTHrP promoter luciferase reporter, a 30% decrease in luciferase activity was seen following treatment with dihydrotestosterone. These results indicate that PC-3 cell growth correlates inversely with androgen sensitivity and directly with PTHrP production in vitro and in vivo, androgens can regulate PTHrP production, and the androgen effect on PTHrP is mediated at least in part by transcriptional regulation via the androgen receptor.
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PMID:Androgen regulation of parathyroid hormone-related peptide production in human prostate cancer cells. 1258 62

Recent data have implicated macrophage inflammatory protein-1alpha (MIP-1alpha) in multiple myeloma (MM)-associated osteolysis. However, it is unclear whether the chemokine's effects are direct, to enhance osteolysis, or indirect and mediated through a reduction in tumor burden, or both. It is also unclear whether MIP-1alpha requires other factors such as receptor activator of nuclear factor-kappaB ligand (RANKL) for its effects on bone. In murine 5TGM1 (Radl) myeloma-bearing mice, administration of neutralizing anti-MIP-1alpha antibodies reduced tumor load assessed by monoclonal paraprotein titers, prevented splenomegaly, limited development of osteolytic lesions, and concomitantly reduced tumor growth in bone. To determine the effects of MIP-1alpha on bone in vivo, Chinese hamster ovary (CHO) cells secreting human MIP-1alpha (CHO/MIP-1alpha) were inoculated into athymic mice. Mice bearing intramuscular CHO/MIP-1alpha tumors developed lytic lesions at distant skeletal sites, which occurred earlier and were larger than those in mice with CHO/empty vector (EV) tumors. When experimental metastases were induced via intracardiac inoculation, mice bearing CHO/MIP-1alpha tumors developed hypercalcemia and significantly more osteolytic lesions than mice bearing CHO/EV tumors, with intramedullary CHO/MIP-1alpha tumors associated with significantly more tartrate-resistant acid phosphatase-positive (TRAP+) osteoclasts. Injection of recombinant MIP-1alpha over calvariae of normal mice evoked a striking increase in osteoclast formation, an effect dependent on RANK/RANKL signaling because MIP-1alpha had no effect in RANK-/- mice. Together, these results establish that MIP-1alpha is sufficient to induce MM-like destructive lesions in bone in vivo. Because, in the 5TGM1 model, blockade of osteoclastic resorption in other situations does not decrease tumor burden, we conclude that MIP-1alpha exerts a dual effect in myeloma, on osteoclasts, and tumor cells.
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PMID:Dual effects of macrophage inflammatory protein-1alpha on osteolysis and tumor burden in the murine 5TGM1 model of myeloma bone disease. 1264 40

There have been a number of reports suggesting inhibition of prostaglandin production may impact tumor-mediated wasting and levels of associated humoral factors such as hypercalcemia. These reductions were achieved using traditional nonsteroidal anti-inflammatory drugs (NSAIDs), which are often contraindicated in cancer patients. This is especially true during chemotherapeutic regimens due to concerns of bleeding from gastrointestinal and hematopoietic toxicities associated with inhibition of the housekeeping cyclooxygenase enzyme COX-1. Here, we report that celecoxib, one of the new class of selective COX-2 inhibitors, has the potential to reverse tumor-mediated wasting and associated humoral factors such as interleukin (IL)-6 and hypercalcemia in preclinical models of cachexia. Tumor bearing mice in late stage cachexia regained weight within days of the start of celecoxib treatment. Two models were tested. The first was the Colon 26 (Col26) syngeneic murine model that induces high levels of circulating IL-6 and hypercalcemia. The second was the human head and neck 1483 HNSCC xenograft model, which is less inflammatory and produces less prostaglandin than Col26. Despite the observation that no significant impact on tumor growth was observed between vehicle and celecoxib-treated animals over the course of the studies, celecoxib rapidly reversed weight loss in both cachectic models. With the added safety of celecoxib over traditional NSAIDs, these results suggest a possible therapeutic use for celecoxib for treating tumor-mediated wasting.
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PMID:Inhibition of cyclooxygenase-2 by celecoxib reverses tumor-induced wasting. 1471 36

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