Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0153690 (bone metastases)
 6,382 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The discovery and development of the bisphosphonates (BPs) as a major class of drugs for the treatment of bone diseases has been a fascinating journey that is still not over. In clinical medicine, several BPs are established as the treatments of choice for various diseases of excessive bone resorption, including Paget's disease of bone, myeloma and bone metastases, and osteoporosis. Bisphosphonates are chemically stable analogues of inorganic pyrophosphate, and are resistant to breakdown by enzymatic hydrolysis. Bisphosphonates inhibit bone resorption by being selectively taken up and adsorbed to mineral surfaces in bone, where they interfere with the action of the bone-resorbing osteoclasts. Bisphosphonates are internalized by osteoclasts and interfere with specific biochemical processes. Bisphosphonates can be classified into at least two groups with different molecular modes of action. The simpler non-nitrogen-containing bisphosphonates (such as clodronate and etidronate) can be metabolically incorporated into nonhydrolyzable analogues of adenosine triphosphate (ATP) that may inhibit ATP-dependent intracellular enzymes. The more potent, nitrogen-containing bisphosphonates (such as pamidronate, alendronate, risedronate, ibandronate, and zoledronate) are not metabolized in this way but can inhibit enzymes of the mevalonate pathway, thereby preventing the biosynthesis of isoprenoid compounds that are essential for the posttranslational modification of small GTP-binding proteins (which are also GTPases) such as rab, rho, and rac. The inhibition of protein prenylation and the disruption of the function of these key regulatory proteins explain the loss of osteoclast activity and induction of apoptosis. The key target for bisphosphonates is farnesyl pyrophosphate synthase (FPPS) within osteoclasts, and the recently elucidated crystal structure of this enzyme reveals how BPs bind to and inhibit at the active site via their critical N atoms. In conclusion, bisphosphonates are now established as an important class of drugs for the treatment of many bone diseases, and their mode of action is being unraveled. As a result their full therapeutic potential is gradually being realized.
 ...
PMID:Bisphosphonates: from bench to bedside. 1683 38

The profound effects of the bisphosphonates on calcium metabolism were discovered over 30 years ago, and they are now well established as the major drugs used for the treatment of bone diseases associated with excessive resorption. Their principal uses are for Paget disease of bone, myeloma, bone metastases, and osteoporosis in adults, but there has been increasing and successful application in pediatric bone diseases, notably osteogenesis imperfecta. Bisphosphonates are structural analogues of inorganic pyrophosphate but are resistant to enzymatic and chemical breakdown. Bisphosphonates inhibit bone resorption by selective adsorption to mineral surfaces and subsequent internalization by bone-resorbing osteoclasts where they interfere with various biochemical processes. The simpler, non-nitrogen-containing bisphosphonates (eg, clodronate and etidronate) can be metabolically incorporated into nonhydrolysable analogues of adenosine triphosphate (ATP) that may inhibit ATP-dependent intracellular enzymes. In contrast, the more potent, nitrogen-containing bisphosphonates (eg, pamidronate, alendronate, risedronate, ibandronate, and zoledronate) inhibit a key enzyme, farnesyl pyrophosphate synthase, in the mevalonate pathway, thereby preventing the biosynthesis of isoprenoid compounds that are essential for the posttranslational modification of small guanosine triphosphate (GTP)-binding proteins (which are also GTPases) such as Rab, Rho, and Rac. The inhibition of protein prenylation and the disruption of the function of these key regulatory proteins explains the loss of osteoclast activity. The recently elucidated crystal structure of farnesyl diphosphate reveals how bisphosphonates bind to and inhibit at the active site via their critical nitrogen atoms. Although bisphosphonates are now established as an important class of drugs for the treatment of many bone diseases, there is new knowledge about how they work and the subtle but potentially important differences that exist between individual bisphosphonates. Understanding these may help to explain differences in potency, onset and duration of action, and clinical effectiveness.
 ...
PMID:Bisphosphonates: mode of action and pharmacology. 1733 36

N-BP, rapamycin and its derivatives have been originally developed respectively as anti-resorptive and anti-fungal agents. In fact, in vitro and in vivo experiments demonstrated that these compounds are multi-functional molecules exerting their effects on tumour cell growth and bone remodelling. The major challenge in treating cancer relates to mutations in key genes such as p53, Rb or proteins affecting caspase signalling carried by many tumour cells. Whether nitrogen containing bisphosphonates (N-BP) are potent bone inhibitors, they also inhibit tumour cell proliferation and increase atypical apoptosis of bone tumour cells regardless of the p53 and Rb status. N-BP may be then considered as effective therapeutic agents in clinical trials of bone tumours. Rapamycin and its derivatives inhibit mTOR dependent mRNA translation both in osteoclasts and tumour cells. Cellular physiological mechanisms regulated by mTOR integrate many environmental parameters including growth factors, hormones, cytokines, amino acids, energy availability and cellular stresses that are coupled with cell cycle progression and cell growth. Rapamycin and its derivatives as well as N-BP must be considered as bi-(multi) functional molecules affecting simultaneously bone and tumour metabolisms. The present survey describes these two molecular families and discusses their therapeutic interests for primary bone tumours and bone metastases.
 ...
PMID:mTOR inhibitors (rapamycin and its derivatives) and nitrogen containing bisphosphonates: bi-functional compounds for the treatment of bone tumours. 1758 50

Patients with metastatic colorectal carcinoma (CRC) often develop bone metastases with a high risk of complications. Ibandronate is a novel single-nitrogen bisphosphonate that has been shown to be effective for treating bone metastases from breast cancer. A randomized, placebo-controlled trial was conducted to evaluate the efficacy and safety of ibandronate in patients with bone metastases from CRC. The primary efficacy end point was the proportion of patients with skeletal-related events (defined as pathologic fracture, spinal cord compression, radiation therapy to bone, change in antineoplastic therapy or surgery to bone). Secondary end points included time to first skeletal event, skeletal morbidity rate (events/year) and time to progression of bone lesions. In 73 patients with CRC, treatment with intravenous ibandronate 6 mg administered via a 15-min infusion significantly reduced the proportion of patients with skeletal events (39% vs. 78% with placebo; P = 0.019) and prolonged the time to first event by at least 6 months (median >279 vs. 93 days with placebo; P = 0.009). Ibandronate also significantly reduced the skeletal morbidity rate (mean 2.36 vs. 3.14 with placebo; P = 0.018) and prolonged time to progression of bone lesions (214 days vs. 81 days with placebo; P = 0.018). Ibandronate was well tolerated with very rare grade 3 or 4 toxicity. Furthermore, the incidence of renal adverse events was comparable with placebo and there were no clinically relevant changes in serum creatinine. Ibandronate provided significant clinical benefits for patients with bone metastases secondary to CRC. These results indicate that ibandronate may be an effective treatment for patients with metastatic bone disease following CRC. Larger studies are required for further assessment.
 ...
PMID:Ibandronate is effective in preventing skeletal events in patients with bone metastases from colorectal cancer. 1794 70

The bisphosphonates (BPs) are well established as the treatments of choice for disorders of excessive bone resorption, including Paget's disease of bone, myeloma and bone metastases, and osteoporosis. There is considerable new knowledge about how BPs work. Their classical pharmacological effects appear to result from two key properties: their affinity for bone mineral and their inhibitory effects on osteoclasts. Mineral binding affinities differ among the clinically used BPs and may influence their differential distribution within bone, their biological potency, and their duration of action. The inhibitory effects of the nitrogen-containing BPs (including alendronate, risedronate, ibandronate, and zoledronate) on osteoclasts appear to result from their inhibition of farnesyl pyrophosphate synthase (FPPS), a key branch-point enzyme in the mevalonate pathway. FPPS generates isoprenoid lipids used for the posttranslational modification of small GTP-binding proteins essential for osteoclast function. Effects on other cellular pathways, such as preventing apoptosis in osteocytes, are emerging as other potentially important mechanisms of action. As a class, BPs share several common properties. However, as with other classes of drugs, there are obvious chemical, biochemical, and pharmacological differences among the various individual BPs. Each BP has a unique profile that may help to explain potential important clinical differences among the BPs, in terms of speed of onset of fracture reduction, antifracture efficacy at different skeletal sites, and the degree and duration of suppression of bone turnover. As we approach the 40th anniversary of the discovery of their biological effects, there remain further opportunities for using their properties for medical purposes.
 ...
PMID:Bisphosphonates: an update on mechanisms of action and how these relate to clinical efficacy. 1805 45

Cancer patients suffering from bone metastases are at increased risk for skeletal complications, which contribute to increased morbidity and negatively affect patient quality of life. Therefore, there has been great interest in the development of clinical therapies to prevent bone metastases. Bisphosphonates are currently used for the treatment of bone metastases secondary to solid tumors, including tumors of the breast, prostate, and lung. Current evidence indicates that nitrogen-containing bisphosphonates may have antitumor potential. Preclinical studies using in vitro and in vivo cancer models have shown that zoledronic acid, a third-generation bisphosphonate, can inhibit angiogenesis, invasion and adhesion of tumor cells, and overall tumor progression. Furthermore, pilot clinical studies suggest that zoledronic acid can prevent bone metastases, and larger clinical trials are under way (AZURE, NSABP-B-34, S0307, ZEUS, G2419) to examine the use of bisphosphonates for prevention of bone metastases in adjuvant therapy settings. Biochemical markers of bone turnover and tumor markers are being characterized and may provide useful tools to identify high-risk patients who may especially benefit from bisphosphonate therapy.
 ...
PMID:Emerging strategies in bone health management for the adjuvant patient. 1806 85

Zoledronic acid (ZA) delays the onset or reduces the incidence of skeletal complications in breast cancer patients with bone metastases. However, there are few data on the long-term renal safety of ZA. We retrospectively evaluated 43 breast cancer patients with bone metastases who received ZA more than 24 months. The following parameters measured prior to first ZA use and after the last dose of ZA administration were compared: serum creatinine (SCr), blood urea nitrogen (BUN), alkaline phosphatase (ALP), calcium (Ca), and phosphorous (P). Forty-three breast cancer patients with documented bone metastases were evaluated. Median age at the start of treatment was 53 years (range 37-77). Median overall duration of ZA administration was 36 months (25-62). There were no statistically significant differences in the pre- and post-treatment levels of SCr, BUN, Ca and P. However, ALP levels after long-term ZA administration were decreased significantly (P<0.05). More than 24 months of ZA administration did not adversely affect the renal function. ZA can be used safely in breast cancer patients with bone metastases beyond 2 years.
 ...
PMID:Renal safety of zoledronic acid administration beyond 24 months in breast cancer patients with bone metastases. 1819 80

Zoledronic acid (Zometa is a third-generation nitrogen-containing parenteral bisphosphonate indicated for the treatment of bone metastases due to solid tumours or multiple myeloma and for hypercalcaemia of malignancy (HCM). In patients with advanced breast or prostate cancer, zoledronic acid 4 mg every 3-4 weeks for up to 15 months significantly reduced the proportion of patients with > or =1 skeletal-related event (SRE), excluding HCM, compared with placebo. In patients with advanced breast cancer or multiple myeloma, the incidence of SREs was similar in patients treated with zoledronic acid 4 mg or pamidronic acid 90 mg every 3-4 weeks for up to 25 months but, in breast cancer patients, zoledronic acid reduced the risk of SREs, including HCM, by an additional 20% compared with pamidronic acid. In modelled cost-utility studies comparing direct costs based on efficacy and resource-use data from these and/or other trials, results have varied. In the most recent study performed from the perspective of the UK NHS and modelled over a 10-year treatment period in women with advanced breast cancer, intravenous zoledronic acid and oral ibandronic acid were dominant over no treatment. Intravenous zoledronic acid was the most cost effective, in terms of incremental costs per QALY gained, followed by oral ibandronic acid, intravenous pamidronic acid and intravenous ibandronic acid. Two other modelled analyses in patients with advanced breast cancer, also conducted from the perspective of the NHS, evaluated the cost utility of three bisphosphonate therapies in patients receiving hormonal therapy or intravenous chemotherapy. Analyses were modelled over 14.3 months (i.e. expected survival) and assumptions varied markedly from results in clinical breast cancer trials. Also, efficacy assumptions for zoledronic acid were not based on clinical trials with the drug. The results of these analyses suggest that oral ibandronic acid is more cost effective than intravenous zoledronic acid and intravenous pamidronic acid in terms of incremental cost per QALY gained. In a global, 15-month modelled cost-effectiveness analysis of patients with advanced prostate cancer, conducted from a third-party perspective, the incremental cost per QALY gained for zoledronic acid versus no treatment was $US159 200 (year 2000 value), which is about 3-fold greater than commonly accepted thresholds for cost effectiveness. In conclusion, a recent modelled economic analysis suggests that intravenous zoledronic acid 4 mg is dominant relative to no treatment in the management of bone metastases in patients with advanced breast cancer. In contrast, in patients with advanced prostate cancer, the incremental cost per QALY gained for zoledronic acid 4 mg versus no treatment was predicted to be higher than commonly accepted thresholds. Compared with other bisphosphonates in the setting of advanced breast cancer, intravenous zoledronic acid was more cost effective than oral or intravenous ibandronic acid and intravenous pamidronic acid in one study, but less cost effective than oral ibandronic acid in another. Further efficacy and economic data comparing intravenous zoledronic acid with oral ibandronic acid are needed. Meanwhile, zoledronic acid appears to be the most cost effective intravenous bisphosphonate for the management of bone metastases in patients with advanced breast cancer and possibly in patients with different types of advanced solid tumours.
 ...
PMID:Zoledronic acid: a pharmacoeconomic review of its use in the management of bone metastases. 1828 18

Bone is the most common organ for tumor metastasis, especially in patients with cancers of the breast or prostate. Bone metastases disrupt skeletal metabolism and result in considerable skeletal morbidity, including intractable, chronic bone pain, hypercalcemia of malignancy, pathologic fracture and spinal-cord compression. In addition to the chronic pain caused by bone metastases, skeletal-related events (SREs) such as pathologic fractures and spinal-cord compression can result in acute increases in pain. These effects can severely impair mobility and contribute to a general decrease in quality of life. Palliative options to treat bone metastases include radiotherapy, analgesics, surgery and bisphosphonates. These drugs bind to the surface of the bone and impair osteoclast-mediated bone resorption, and reduce the tumor-associated osteolysis that is initiated by the development of skeletal metastases. In addition to preventing SREs, bisphosphonates can palliate bone pain caused by a variety of solid tumors. This Review summarizes the clinical trial data of bisphosphonates for the prevention of SREs and the palliation of bone pain. Among these agents, nitrogen-containing bisphosphonates are recognized as the most effective, and zoledronic acid has demonstrated the broadest clinical utility.
 ...
PMID:Effect of bisphosphonates on pain and quality of life in patients with bone metastases. 1919 May 92

Bisphosphonates are strong inhibitors of osteoclastic bone resorption in both benign and malignant bone diseases. The nitrogen-containing bisphosphonates (N-BPs) have strong cytotoxicity via inhibition of protein prenylation in the mevalonate pathway, and also demonstrate direct cytostatic and proapoptotic effects on prostate cancer cells. We confirmed the usefulness of a co-culture system comprised of prostatic LNCaP cells, ST2 cells (mouse-derived osteoblasts) and MLC-6 cells (mouse-derived osteoclasts) in vitro. N-BPs (pamidronate and zoledronic acid) inhibited both androgen receptor transactivation and tumor cell proliferation by suppressing the activities of both osteoclasts and osteoblasts with low-dose exposure. This indirect inhibition of prostate cancer cells via bone cells could be beneficial in treating prostate cancer patients with bone metastases.
 ...
PMID:Indirect antitumor effects of bisphosphonates on prostatic LNCaP cells co-cultured with bone cells. 1941 50


<< Previous 1 2 3 4 5 6 7 8 Next >>