Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Four antisera raised in the goat have very different properties: all recognized the immunoreactive calcitonin (iCT) of medullary carcinoma of the thyroid (MCT), one the response of normal subjects to induced or endogenous hypercalcemia and 2 others a different molecular species which occurs in half the patients with cancer of breast and 3/4 of patients with cancer of the lung. The latter two antisera are most sensitive to the 22-32 sequence of human calcitonin. Depending on the antiserum used, 4 or 7 peaks of immunoreactivity are found in eluates by column chromatography or stimulated serum from MCT. Not all elevated levels of iCT in serum are diagnostic of MCT and ectopic production by lung and breast cancer must be considered. Presence of higher levels of iCT with greater amounts of cancer tissue and undetectable levels after surgery or radiotherapy when using antisera which require intact molecule of calcitonin for recognition suggest the possibility that sequential calcitonin levels with differentiating antisera may be helpful in assessing the extent of disease and response to therapy.
 ...
PMID:Immuno-heterogeneity of the calcitonins of hypercalcemia, breast and lung cancers and medullary carcinoma of thyroid. 47 68

A case of bone metastases from breast cancer is reported. After 6 months of therapy with calcitonin, the skeletal radiological examination showed an evident change in the roentgenographic pattern of a large metastasis of the left femur. A possible relationship between the calcitonin treatment and the radiological change is discussed.
 ...
PMID:Bone metastases from breast cancer treated with calcitonin. Case report. 54 14

Immunoreactive calcitonin was found in extracts of seven out of eight consecutive breast carcinomas and four selected lung carcinomas, but not in extracts of benign breast lesions or normal tissues. This suggests that the high plasma calcitonin levels observed in patients with a wide variety of cancers reflect ectopic production of calcitonin by cancer tissue, and that the radioimmunoassay for calcitonin could prove to be of value in the detection and management of malignant disease, particularly breast cancer.
 ...
PMID:Calcitonin in breast and lung cancer. 94 90

The human breast cancer cell line T 47 D expresses calcitonin (CT) receptors that are coupled to adenylate cyclase and which reveal a dose-dependent cyclic AMP response to CT. We used this model to establish an in vitro bioassay for synthetic human CT (hCT) preparations to overcome some of the obstacles of the standard rat hypocalcemia in vivo bioassay. The detection limit of the in vitro bioassay was 1 x 10(-10) M hCT (EC 50: 8.7 pM +/- 26%) compared to 7.3 x 10(-9) M (EC 50: 7.2 microM +/- 32%) for the in vivo bioassay. The relative potencies of test preparations revealed a good correlation (r = 0.89) and several hCT-related substances produced comparable results when tested by the two methods. The standard deviations of precision and accuracy, however, were significantly smaller (P less than 0.05) for the in vitro bioassay. According to these data the T 47 D in vitro bioassay is more sensitive, superior in precision and accuracy, and comparable in specificity to the rat hypocalcemia bioassay.
 ...
PMID:A new in vitro bioassay for human calcitonin: validation and comparison to the rat hypocalcemia bioassay. 131 97

Nineteen patients with postmenopausal osteoporosis were treated with 200 u (15 nmol) synthetic salmon calcitonin (sCT) intranasally per day for 15 months. Six months after the start of the nasal administration of sCT, antibodies were recognized in 7, and after 15 months in 10 of the 19 patients studied. The half-maximal dilution of serum binding to 60 pmol/l [125I]sCT (dilution-50) ranged from 2 to 490, and half-maximal inhibition of [125I]sCT binding (60 pmol/l) from 91 to 221 pmol/l sCT. In a cultured breast cancer cell line (T47D) cAMP production was stimulated by sCT (EC50 70 pmol/l). Stimulated cAMP production by sCT (50 pmol/l) was reduced to between 4% and 23% in the presence of serum from patients with antibody dilution-50 of [125I]sCT binding exceeding 32. In patients with lower titer antibodies cAMP production was only marginally suppressed. The values of patients with postmenopausal osteoporosis were in the range of those of earlier studied patients with Paget's disease and clinical resistance to sCT. There was a linear relation between the antibody dilution-50 and the serum dilution required for half-maximal inhibition of cAMP production (P less than 0.01). In conclusion, neutralizing antibodies to sCT may contribute to the decreased responsiveness of bone mineral loss during prolonged treatment with sCT.
 ...
PMID:Formation of neutralizing antibodies during intranasal synthetic salmon calcitonin treatment of postmenopausal osteoporosis. 179 Mar 95

The effects of salm-calcitonin on breast cancer osteolytic skeletal metastases have been studied on conventional radiographs. Radiographic criteria for positive response have been defined. It is concluded that radiographs are inadequate for assessing the effects of salm-calcitonin.
 ...
PMID:Conventional radiograms for assessment of salm-calcitonin therapy for bone metastases from breast carcinoma. 203 99

In the course of a phase II study 15 patients (nine women and six men; mean age 58 [45-69] years) received 300 mg clodronate daily during a total of 16 episodes of tumour-induced hypercalcaemia. Four women had breast cancer, four patients had plasmocytoma and four had bronchial carcinoma. One woman each had leiomyosarcoma or squamous cell carcinoma of the uterus or pancreatic carcinoma, respectively. No other calcium-lowering treatment, such as forced diuresis, glucocorticoids, calcitonin or mithramycin, was employed. As early as two days after onset of treatment the serum calcium concentration fell significantly from 3.63 +/- 0.42 to 2.80 +/- 0.40 mmol/l. After a mean interval of 4.3 days the hypercalcaemia had been eliminated during 15 of the 16 episodes. The treatment was not adequate in one patient with paraneoplastic hypercalcaemia. The results indicate that this medication is to be recommended as a standard treatment of tumour-induced hypercalcaemia; side effects are minimal.
 ...
PMID:[Monotherapy with clodronate for tumor-induced hypercalcemia]. 213 27

Hypercalcemia is a common metabolic problem in patients with metastatic breast cancer. Osteolytic bone destruction with release of calcium into circulation and humoral factors can lead to hypercalcemia. Clinical manifestations may be so mild as to be overlooked or include severe nervous system, gastrointestinal and renovascular complications. Treatment with saline infusions to replenish intravascular volume and restore renal function provides the basis for other therapeutic interventions. A variety of pharmacologic approaches include intravenous fluids, diuretics, steroids, calcitonin, bisphosphonates, and plicamycin. Investigation of new agents, particularly bisphosphonates and gallium, continues. The optimal treatment of hypercalcemia in breast cancer patients has not been defined, though control of metastatic disease obviously is of utmost importance.
 ...
PMID:Management of hypercalcemia in breast cancer. 214 69

Osteoporosis is more readily prevented than treated, and early intervention with effective therapy would be expected to reduce significantly the impact of osteoporotic fractures among the aging population. For the postmenopausal female population, estrogen is the cornerstone of therapy, and multiple studies have demonstrated efficacy in reducing cortical and trabecular bone loss in the axial and peripheral skeleton. Alternative strategies for those who cannot, or will not, take estrogen and who can be documented to be at increased risk of osteoporosis, include calcium supplementation, progestogens, (particularly the 19-nortestosterone derivatives), calcitonin, diphosphonates, and anabolic steroids. All have been shown in some populations to reduce the rate of bone loss to a greater or lesser extent, although, overall, the data are as yet inconclusive. All regimes, with the exception of moderate calcium supplementation, have negative aspects to their use currently, and further research is required before a definitive alternative to estrogen for prevention of postmenopausal osteoporosis can be recommended. Only estrogens and calcitonin have Food and Drug Administration (FDA) approval for use in the treatment of osteoporosis. In the decision-making process for the woman at mid-life, risk factor assessment, although a poor quantitative tool for the individual patient, is the starting point for the evaluation of patients. Bone mass measurements play a crucial role in assisting the dubious patient (or physician) about the need for therapy. Estrogen use, however, is a more important issue for the postmenopausal female, with sequelae other than its effects on bone to be considered, including effects on cardiovascular disease, endometrial and breast cancer, which must be considered in the equation of risk-benefit. The greater the risks and costs of the intervention strategies available, the more important effective identification of the target population becomes. Estrogens, however, provide the most effective preventive treatment for osteoporosis. This review will deal primarily with the decision to introduce estrogen treatment, and the efficacy of estrogens,as well as alternative forms of prevention.
 ...
PMID:Alternative strategies for prevention of postmenopausal osteoporosis. 251 4

T47D human breast cancer cells and BEN human lung cancer cells were preincubated with the tumor-promoting phorbol ester phorbol 12-myristate 13-acetate (PMA). In both cell lines there was a decrease in the binding of 125I-labeled salmon calcitonin ([125I]sCT) which was dependent on the dose and time of exposure to PMA. The effect on binding comprised at least two components: the apparent affinity for binding of [125I]sCT was decreased by PMA, and the rate of internalization of bound [125I]sCT was increased more than 2-fold in the presence of PMA. By using dinitrophenol to inhibit cellular metabolic energy and, therefore, receptor internalization, the PMA effects on receptor affinity were dissociated from those on endocytosis. The effects on binding were reflected in a decreased stimulation by sCT of adenylate cyclase activity. This was specific for the calcitonin receptor system, since PMA had no effect on prostaglandin-E2-stimulated adenylate cyclase in the T47D cell. Protein kinase-C (PKC) was implicated in the inhibitory effects of PMA on both binding and adenylate cyclase activation, since inhibition was reduced by simultaneous incubation with the PKC inhibitors H7 and H8. These results suggest that PKC is capable of mediating down-regulation of the CT receptor, and this is most likely by phosphorylation of the receptor itself or an associated protein.
 ...
PMID:Protein kinase-C-induced down-regulation of calcitonin receptors and calcitonin-activated adenylate cyclase in T47D and BEN cells. 255 60


1 2 3 4 5 6 7 8 9 10 Next >>