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

Hypercalcemia in association with skeletal metastases is common; hypocalcemia in this clinical setting is unexpected, though it has also been described, most commonly with primary lesions of the breast or prostate. In a subset of hypocalcemic patients with breast cancer, there is an inappropriate endocrinologic response as evidenced by a relative hypoparathyroidism and an elevation in the serum level of calcitonin. We have described a representative case and reviewed the literature.
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PMID:Hypocalcemia and an inappropriate endocrine response in osteoblastic metastatic breast cancer. 255 99

Bone metastasis is one of the characteristic behavior of recurrent breast cancer. Usually, X-ray detect and/or bone scintigraphy are used to evaluate bone metastasis. However, false positive cases are occasionally encountered in these modalities. This is a report of the results from the measurement of serum osteocalcin (OC) in breast cancer with bone metastasis. OC is one of the protein dependent on Vitamin K. The results were as follows: 1) Serum levels of OC in 56 patients with primary breast cancer were measured. The mean level of serum OC was significantly higher than that in patients with benign breast disease. But the comparisons in each stage were not statistically significant. 2) The mean serum OC level in patients of primary breast cancer with bone metastasis was higher than that in breast cancer without bone metastasis (p less than 0.05). This was remarkable in the patients of recurrent breast cancer (p less than 0.01). 3) Serum OC levels in bone metastasis patients were increased in group with normocalcemia, while it was normal or decreased in that with hypercalcemia. There was no significant correlation between either serum OC and ALP values, or between serum OC and serum Ca values. The slight positive and reverse correlation were observed between OC and ALP, OC and sCa, respectively. 4) In many cases with bone metastasis, serum OC levels were elevated before bone lesions were detected by bone scintigraphy. 5) In advanced stage of the patients with bone metastasis and hypercalcemia, serum OC level decreased. The increased level of serum OC was maintained when high dose of calcitonin was administered.
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PMID:[Clinical evaluation of serum osteocalcin in patients with bone metastasis of breast cancer]. 261 77

Tumour markers are often circulating tumour-associated indicators of tumour development. As such they are not suitable for tumour screening and localization, but valuable as adjuncts for medical follow-up care of tumour patients, where their serum level alterations may anticipate the clinical detection of tumour behaviour by a lead time of 1 to 6 months before other methods. The following tumour may be controlled by established markers: endocrine tumours by NSE, calcitonin, parathormone, 5-HIAA, catecholamines/metabolites etc.; head-neck tumours: SCC, CEA; thyroid carcinoma: TG, calcitonin; lung cancer: CEA, NSE, SCC; liver cancer: AFP (PLC), CA 19-9 (cholangiocell.), CEA (secondary): biliary tract and pancreatic cancer: CA 19-9; colorectal carcinoma: CEA, CA 19-9; squamous cell carcinoma (ENT, oesophagus, anal): SCC; breast cancer: CEA and CA 15-3; ovarian cancer: CA 125 (epithelial), CA 19-9 (mucinous); germ cell tumours (ovary including trophoblastic tumours/testes): AFP and HCG; prostatic cancer: PAP and PSA; bladder cancer: TPA.
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PMID:[Clinical relevance of tumor markers]. 267 6

Some effects of calcitonin (CT) can also be produced by calcitonin gene-related peptide (CGRP), an alternative product of the calcitonin gene. This might be mediated by interaction of CGRP at the CT-receptor site. The human breast cancer cell line T47D possesses well characterized CT-receptors (KD = 2.3 x 10(-10) M for 125I salmon CT). 50% inhibition of 125I-sCT binding was achieved with 10(-9) M sCT, 5 x 10(-6) M rat CGRP and 10(-5) M human CGRP. Half maximal cAMP production in T47D cells was seen with 6 x 10(-10) M sCT, 5 x 10(-6) M rCGRP and 10(-5) M hCGRP. Binding and displacement capacity as well as the biological activity of CT and CGRP seems to correlate well. These findings suggest that CGRP in pharmacological doses acts via the CT-receptor. This could be explained by the homology and conformational similarities between CT and CGRP.
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PMID:Action of calcitonin gene-related peptide at the calcitonin receptor of the T47D cell line. 282 11

The effects of salmon calcitonin (sCT) and human calcitonin (hCT) and of rat (r) and human (h) calcitonin gene-related peptide (CGRP) on intracellular cAMP accumulation were tested in human breast cancer cells (MCF7). In addition to the well known stimulatory effect, each showed a significant inhibitory effect on cAMP accumulation at low doses. cAMP concentrations in response to sCT, hCT, and rCGRP decreased to 47 +/- 2, 45 +/- 4, and 56 +/- 2% (mean +/- 1 SE) of baseline. The potency ratios for the inhibitory action of sCT, hCT, and rCGRP (1:0.25:0.005, respectively) were similar to the potency ratios for stimulatory action (1:0.3:0.005). The inhibition of cAMP accumulation developed at 300-fold lower peptide concentrations than the stimulation. Preincubation with pertussis toxin or with manganese completely abolished the inhibitory effect of the peptides, suggesting that this is mediated by an inhibitory adenylate cyclase regulatory protein. sCT, hCT, and CGRP each showed unique patterns with regard to time course of inhibition of cAMP accumulation. We conclude that 1) CT can activate an inhibitory adenylate cyclase regulatory protein and a stimulatory adenylate cyclase regulatory protein, and 2) CT effect on an inhibitory adenylate cyclase regulatory protein in MCF 7 cells is evident at far lower hormone concentrations than its effect on a stimulatory adenylate cyclase regulatory protein.
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PMID:Dual effects of calcitonin and calcitonin gene-related peptide on intracellular cyclic 3',5'-monophosphate in a human breast cancer cell line. 283 Oct 23

Two methods have been used to covalently cross-link [125I]-salmon calcitonin to its receptor on a human lung carcinoma cell line, BEN, and the human breast cancer cell lines T47D and MCF 7. The first method was to use a specific photoaffinity derivative of salmon calcitonin and the second employed the chemical cross-linker, disuccinimidyl suberate. In both cases a cross-linked component of approximate molecular weight 80-90,000 on BEN cells was identified by polyacrylamide gel electrophoresis. This is consistent with the size of the cross-linked component found on T47D breast cancer cells using the photoactive salmon calcitonin as described in previous work. Disuccinimidyl suberate was unable to cross-link [125I]-salmon calcitonin either on T47D or MCF cells. However, photoactive salmon calcitonin cross-linked to a component of approximately 80-90,000 Mr on the MCF 7 cells. Thus, whereas the photoactive salmon calcitonin could cross-link a similar receptor component in all cell lines, the ability of disuccinimidyl suberate to do so was apparently cell specific. These data confirm that the calcitonin receptor comprises a component of approximately 85,000 Mr in cell lines examined thus far.
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PMID:Identification of the calcitonin receptor by chemical cross-linking and photoaffinity labeling in human cancer cell lines. 284 28

A 24 hr incubation of T-47D human breast cancer cells with R5020, a synthetic progestin, resulted in a 200-250% increase in the specific binding of human growth hormone (hGH) and epidermal growth factor (EGF) by these cells. This effect was specific for progestins in that similar responses were observed with progesterone, medroxyprogesterone acetate and ORG 2058 but no significant increases in hGH or EGF binding were observed in cells incubated with testosterone, estradiol or hydrocortisone. Increased binding was due to an increase in the concentration of receptors (hGH, control = 6,490 +/- 500, progestin treated = 13,180 +/- 3,270 sites/cell; EGF, control = 33,380 +/- 7,410, progestin treated = 67,460 +/- 20,330 sites/cell) while the affinity constants for the hormone-receptor interactions were unchanged by progestin treatment. The specific binding of insulin, calcitonin, transferrin and concanavalin A was unaffected by these treatments. It is concluded that expression of hGH and EGF receptors in this breast cancer cell line is regulated by progestins.
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PMID:Regulation of growth hormone and epidermal growth factor receptors by progestins in breast cancer cells. 299 26

Epidermal growth factor (EGF) receptors are present in human breast cancer and probably mediate the effects of EGF and the autocrine effects of alpha-transforming growth factors, produced by breast cancer cells. Steroid hormones influence the growth of some human cancers, and both direct and indirect effects on cell proliferation have been proposed. One potential indirect effect of steroids would be to augment sensitivity to other endocrine and autocrine factors by up-regulation of their receptors. We therefore investigated the effects of various steroids on EGF receptor expression in T-47D, MCF-7, and BT 20 human mammary carcinoma cells in culture. Preincubation of T-47D cells for 24 h with a series of androgens, estrogens, glucocorticoids, and progestins resulted in a significant enhancement of specific 125I-EGF binding in the presence of progestins only. Increased binding of EGF was associated with neither a change in cell number nor changes in the specific binding of concanavalin A, insulin, or calcitonin but was accompanied by an increase in lactogenic receptor expression. When assayed at 20 degrees C, increased EGF binding was due to an increase in receptor number (33,380 +/- 7,410 sites/cell in control cultures; 67,460 +/- 20,330 sites/cell in cultures treated with 1 nM medroxyprogesterone acetate for 24 h; P less than 0.05) without a change in receptor affinity. Two- to 3-fold increases in receptor number were also apparent when binding was measured at 4 degrees C, indicating that the effect was due to an increase in expression of receptor at the cell surface rather than progestin effects on internalization and degradation. These data illustrate that the expression of EGF receptor in some breast cancer cells is regulated in part by mechanisms mediated via the progesterone receptor, since the effect was confined to progestins, potency among a series of progestins was correlated with their affinities for progesterone receptor, and sensitivity among the three cell lines studied was related to the presence and concentration of cellular progesterone receptor.
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PMID:Progestin regulation of epidermal growth factor receptor in human mammary carcinoma cells. 300 May 83

Progesterone receptors (PgR) are present in many breast cancers, but few specific actions of progestins in breast cancer cells have been reported. We now report that progestins specifically modulate lactogenic receptor expression in cultured T-47D and MCF-7 human mammary carcinoma cells. When T-47D cells were preincubated for 24 h with 1 nM medroxyprogesterone acetate (17 alpha-acetoxy-6 alpha-methyl-4-pregnene-3,20-dione), specific binding of [125I]human GH ([125I]hGH) and [125I]human PRL was increased to 205 +/- 22% (+/- SE) (P less than 0.01) and 175 +/- 32% (P less than 0.05), respectively, of that in control cultures. There was no significant effect on cell number and no significant enhancement of specific binding of [125I]porcine insulin, [125I]salmon calcitonin, [125I]human transferrin, or [3H] Concanavalin A. Lactogenic receptor number was increased from 6,490 +/- 500 (n = 12) to 13,180 +/- 3,270 (n = 7; P less than 0.01) sites/cell, with no significant change in affinity for hGH. Progesterone, which is readily metabolized by these cells, was less potent than the synthetic progestins (medroxyprogesterone acetate, R 5020 (17 alpha, 21-dimethyl-19-norpregn-4,9-diene-3,20-dione), and ORG 2058 (16 alpha-ethyl-21-hydroxy-19-norpregn-4-en-3,20-dione), but physiological concentrations of progesterone (1 nM) significantly enhanced specific binding of [125I]hGH to 153 +/- 23% of the control value (n = 6; P less than 0.05). Physiological concentrations of androgens, estrogens, and glucocorticoids had no significant effect. MCF-7 cells were considerably less sensitive to these effects of progestins than T-47D cells, probably due to the lower PgR concentration in MCF-7 cells. These observations, which indicate that lactogenic receptor expression is controlled, at least in part, by progestins in these mammary carcinoma cell lines, may have important implications in the management of human breast cancer, where high levels of this receptor may reflect a functional PgR and a highly hormone-dependent phenotype.
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PMID:Modulation of lactogenic receptors by progestins in cultured human breast cancer cells. 300 Nov 23

A woman with exocrine pancreatic cancer presented a syndrome of humoral hypercalcemia of malignancy (HHM). Either urea extract or acid/ethanol extract of the tumor showed a dose-dependent activity to elevate cyclic adenosine monophosphate (AMP) level in rat bone cells in primary culture. When each population obtained by the sequential digestion of rat fetal calvaria was cultured individually and cyclic AMP responses to parathyroid hormone (PTH), calcitonin, and tumor extract were examined, tumor extract-sensitive cells showed a similar distribution to PTH-sensitive cells. Tumor extract and PTH, but not calcitonin, increased cyclic AMP in osteogenic cell line MC 3T3-E1. PTH receptor-mediated increase of cyclic AMP was indicated by an antagonistic action of PTH analogue, (3-34) hPTH, on increase of cyclic AMP in MC 3T3-E1 elicited by tumor extract. Human breast cancer derived cell line MCF-7 had calcitonin-sensitive adenylate cyclase, but neither PTH nor tumor extract increased cyclic AMP in the cells. On Bio-Gel P-60 column, the activity to stimulate bone cell cyclic AMP was eluted as a single peak at the molecular size between 6.5 K and 12.4 K. It was concluded that pancreatic cancer, although rather exceptional as a cause of HHM, produced a factor very similar to that reported in representative HHM tumors of human and animal models.
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PMID:Enhancement of cyclic adenosine monophosphate content in bone cells by the factor extracted from a pancreatic cancer associated with hypercalcemia. 301 45


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