Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fetal skin fibroblasts produce a soluble "migration stimulating factor" (MSF) which is not made by their normal adult counterparts. MSF stimulates the migration of adult skin fibroblasts into 3D collagen gels, thus providing the basis of a convenient bioassay for its presence. We have previously reported that MSF stimulates hyaluronic acid (HA) synthesis by adult skin fibroblasts and that this effect on matrix deposition appears to be responsible for the observed increase in cell motility. In the present study, wound fluid samples were collected from 18 patients undergoing surgery for various nonmalignant conditions and these were then fractionated according to the protocol used to isolate MSF from fetal fibroblast-conditioned medium. Detectable levels of migration stimulating activity were present in 17/18 (94%) of these samples. Paired serum samples obtained both pre- and postoperatively from five patients with positive wound fluid samples were also analyzed for MSF activity; such activity was found in only 1/5 (20%) of the preoperative and 0/5 (0%) of the postoperative serum samples. These data suggest that the MSF present in wound fluid is not derived from a plasma transudate or from platelet degranulation, but may reflect the transient and localized reinitiation of MSF production by adult fibroblasts in response to wounding. Taken together with previous observations regarding the effect of MSF on fibroblast migration and HA synthesis, our data suggest a possible physiological function of MSF in the wound healing response. Previous studies have revealed that MSF is produced by a subpopulation of apparently persistent fetal-like skin fibroblasts obtained from breast cancer patients and is also found in the serum of these individuals. Wound fluid and serum samples were accordingly collected from patients undergoing surgery for various types of malignant conditions or with a previous history of cancer; detectable levels of MSF activity were found in 8/10 (80%) of these wound fluid samples, 2/3 (66.6%) of the preoperative, and 3/3 (100%) of the postoperative paired serum samples. These findings suggest that the presence of detectable serum levels of MSF is not restricted to breast cancer and may be a general feature of malignant disease.
Exp Mol Pathol 1992 Aug
PMID:Detection of migration stimulating activity in wound fluid. 139 94

NADPH cytochrome c (P-450) reductase was purified from human placental microsomes using a combination of affinity and gel filtration chromatography. Affinity chromatography using agarose-hexane-adenosine 2'5 diphosphate resulted in two protein bands being detected by SDS-PAGE of approximate MwS 68 and 75 kDa. Fractions containing the two proteins were pooled, and then resolved using Sephacryl S-200. Both of the purified proteins displayed enzyme activity, measured by their ability to reduce cytochrome c. The 75 kDa protein obtained was used to immunize three female New Zealand white rabbits. The IgG fraction was partly purified from rabbit sera which suppressed placental microsomal NADPH cytochrome c reductase activity by > 80% using 33% ammonium sulphate. The procured antibody suppressed androstenedione aromatase activity in microsomal preparations of human placental and breast adipose tissue, and NADPH cytochrome c reductase activity in prostate (benign and malignant), MDA-MB-231 breast cancer cells, breast adipose, Hep G2 hepatoma cells and placental microsomal preparations. The extent of NADPH cytochrome c reductase inhibition varied in the order of malignant prostate < benign prostate < MDA < breast adipose < Hep G2 < placenta. The results suggest that human placental NADPH cytochrome c (P-450) reductase shares common antigenic epitopes pertinent to its capability of reducing cytochrome c in all of the above-mentioned tissues. In attempting to associate possible changes in NADPH cytochrome c reductase activity imposed by neoplasia to the obtained immunochemical cross reactivity and enzyme activity results, it was noted that microsomes obtained from MDA cells exhibited enzyme activity significantly less than that of breast adipose microsomes (1.6 and 8.1 nmol/min/mg protein, respectively) and by comparison showed 6% less homology towards the placental antibody. The results obtained for benign and malignant prostate showed no significant difference between the neoplastic states as adjudged by enzyme activity and immunochemical assays.
J Steroid Biochem Mol Biol 1992 Nov
PMID:Immunochemical specificity of placental NADPH cytochrome c (P-450) reductase in neoplastic and non-neoplastic human tissue. 141 86

Breast cancer is the most common malignant tumor among women, comprising an estimated 24% of all cancer cases and 18% of all cancer deaths. At least half of the patients with primary breast cancer will ultimately die by metastatic disease. The tumor characteristics, the natural course of the disease and the response to therapy vary strongly. A number of recently detected cell biological parameters such as oncogenes/suppressor genes, growth factors and secretory proteins are more or less important prognostic factors, because they influence the characteristics and behavior of a tumor with respect to metastatic pattern, extent of cellular differentiation, growth rate and response to treatment. However, there is no clear consensus how best to identify patients at high or low risk. In our experience c-myc amplification and pS2 protein are strong prognosticators for relapse rate, while in advanced disease (apart from a negative estrogen/progesterone receptor/pS2 status) amplification of HER2/neu is a good prognosticator for failure to endocrine therapy. In the diagnosis of breast cancer, in vivo imaging of tumors by labeled hormones or other factors also forms a new development which might have implications for treatment too. With respect to treatment both endocrine and chemotherapy can cure a minority of patients with micrometastases, but in patients with advanced disease only a prolongation of (progression-free) survival can be reached. Response rates decrease with increasing tumor load. In the past decade a number of interesting new endocrine agents has been developed such as new (pure) (anti)steroidal agents, vitamins, aromatase inhibitors, analogs of peptide hormones, prolactin inhibitors and growth factor antagonists. However, less is known on the (potential) interaction between hormones, chemotherapeutic agents, retinoids, cytokins, growth factor antagonists and irradiation. Rapid detection of new powerful combination therapies are needed to improve treatment results during the nineties.
J Steroid Biochem Mol Biol 1992 Sep
PMID:Clinical breast cancer, new developments in selection and endocrine treatment of patients. 144 97

To investigate further the molecular mechanisms of progestin regulation of human breast cancer cell growth, we studied the effect of progestins on expression of the protooncogene c-jun and other members of the jun family, jun-B and jun-D, in T-47D human breast cancer cells. The progestin medroxyprogesterone acetate (MPA) increased c-jun mRNA levels in a time- and dose-dependent fashion. Maximal effects were seen after 3 h of treatment with 10-100 nM MPA. Under these conditions, the c-jun mRNA was increased 5.4-fold above the control level. Although the c-jun mRNA level was increased by cycloheximide alone, a further 2.4-fold increase was seen when the cells were treated with MPA in the presence of cycloheximide. The p39 c-jun protein was also increased 3.8-fold by this treatment. Maximum levels of p39 c-jun protein were achieved 9 h after treatment, and this level was maintained for at least 24 h. Dexamethasone and dihydrotestosterone did not increase the p39 c-jun protein level under these conditions. However, MPA treatment of T-47D cells resulted in a 55% decrease in overall AP-1 activity, as measured by transient transfection of an AP-1-regulated chloramphenicol acetyltransferase reporter gene. These effects were all reversible by cotreatment with a 10-fold higher concentration of the antiprogestin RU 486. MPA decreased jun-B mRNA levels 50% 1 h after treatment in T-47D cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Endocrinol 1992 Oct
PMID:Regulation of c-jun and jun-B by progestins in T-47D human breast cancer cells. 144 15

Charcoal-dextran stripped serum/plasma supplemented media specifically inhibit the proliferation of estrogen-sensitive cells in culture conditions; estrogens cancel this effect. Here, we further characterize this phenomenon using human estrogen-sensitive breast cancer MCF7 cells and human serum/plasma. The serum/plasma-borne inhibitory activity (estrocolyone-I) is a non-dialyzable, heat-stable (60 degrees C x 2 h), protease-sensitive macromolecule and it is not extractable by organic solvents. Estrocolyone-I activity is retained after dialysis against 6 M urea or 10-100 mM dithiothreitol; however, simultaneous treatment with 6 M urea and 10-100 mM dithiothreitol completely abolishes its inhibitory activity. The inhibitory effect of serum is not due to serum albumin, nor to estrogen trapping by albumin or by sex hormone-binding globulin. Substantial purification was achieved by a combination of chromatographic techniques (dye-affinity, ion exchange, hydrophobic interaction chromatography). Estrocolyone-I activity seems to be due to a protein of an apparent native Mw of 70-80 kDa and an isoelectric point of 4.5-4.8.
J Steroid Biochem Mol Biol 1992 Dec
PMID:A plasma-borne specific inhibitor of the proliferation of human estrogen-sensitive breast tumor cells (estrocolyone-I). 147 62

The antiestrogen tamoxifen is used in the treatment of hormone-responsive breast cancer. However, therapeutic failure has frequently been observed in both patients and animal models after long term treatment. We have studied the effect of a point mutation that leads to the substitution of Val for Gly at codon 400 in the ligand-binding domain of the estrogen receptor (ER) on estrogenic and antiestrogenic activities of 4-hydroxytamoxifen (4-OHT) and its derivatives. Stable ER transfectants derived from MDA-MB-231 CL10A, an ER-negative breast cancer cell line, have been used in these studies. 4-OHT and its fixed ring derivatives showed more estrogen-like activity in ER transfectants than in MCF-7, an ER-positive breast cancer cell line. In this study, 4-OHT was a partial agonist of cell growth in the transfectant S30 cells, which express the wild-type ER. However, it was a full agonist in the mutant ER transfectant ML alpha 2H, which expressed ER with Val at codon 400. The increased estrogenic activity of 4-OHT in ML alpha 2H cells was not due to the preferential isomerization of trans 4-OHT to cis 4-OHT, since the nonisomerizable fixed ring trans 4-OHT was a partial agonist for cell growth in S30 cells and was a full agonist in ML alpha 2H cells. Transient transfection using a reporter plasmid containing an estrogen response element demonstrated that fixed ring trans 4-OHT had estrogenic activity in ML alpha 2H cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Endocrinol 1992 Dec
PMID:Point mutation of estrogen receptor (ER) in the ligand-binding domain changes the pharmacology of antiestrogens in ER-negative breast cancer cells stably expressing complementary DNAs for ER. 149 96

In order to better understand the structural requirements for effective high affinity binding of estrogens and antiestrogens by the human estrogen receptor (ER), a comparative study was undertaken in which we examined: 1) native ER from the MCF-7 ER-positive human breast cancer cell line; 2) full length ER expressed in yeast; 3) the ER hormone binding domain (amino acid residues 302-595) expressed in yeast; 4) a bacterially expressed protein A fusion product encoding a truncated ER (amino acid residues 240-595); and 5) a synthetic peptide encompassing amino acids 510-551 of the ER. The binding parameters studied included affinity, kinetics, structural specificity for ligands, and stability. Full length ER expressed in yeast was very similar to the MCF-7 ER in its affinity [dissociation constant (Kd), 0.35 +/- 0.05 nM], dissociation rate (t1/2, 3-4 h at 25 C), and structural specificity for both reversible and covalently attaching affinity ligands. While the truncated ER expressed in yeast was similar to MCF-7 ER in its specificity of ligand binding, it showed a slightly reduced affinity for estradiol (Kd, 1.00 +/- 0.17 nM). The bacterially expressed ER also had a lower affinity for estradiol (Kd, 1.49 +/- 0.16 nM), which may be due in part to an increase in the dissociation rate (t1/2, 0.5 h at 25 C). The attachment of covalent affinity ligands and structural specificity for a variety of reversible ligands was comparable in the bacterially expressed ER to that observed for the receptors expressed in MCF-7 cells and yeast.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Endocrinol 1992 Jun
PMID:Structural requirements for high affinity ligand binding by estrogen receptors: a comparative analysis of truncated and full length estrogen receptors expressed in bacteria, yeast, and mammalian cells. 149 91

Previous studies have shown that in the breast there are multiple forms of the enzyme oestradiol dehydrogenase (E2DH), responsible for the interconversion of oestrone (E1) to oestradiol (E2). We have now re-examined oestrogen metabolism in the breast cancer cell lines (T47D and MCF-7) and have shown that steroids previously shown to inhibit the conversion of E1 to E2 in normal breast tissue failed to do so when added to growing monolayers of these malignant cells. In contrast to earlier estimates in normal breast tissues, the apparent Km for this conversion in monolayers of these malignant cells is shown here to be considerably lower, at around 50 nM. Cell free studies on these cell lines have revealed the presence of a high affinity (for E1) form of this enzyme of Mw approximately 80 kDa. The ability to detect this enzyme in soluble cell fractions appears to be critically dependent on buffer composition. Normal breast epithelial cells and adipose tissue appear to be devoid of this form of E2DH. As this form of E2DH has the highest affinity for the substrate E1 of all the forms in the breast, it is probable that this 80 kDa enzyme is responsible for the conversion of E1 to E2 in cell monolayers. If the observation holds that the 80 kDa enzyme is absent in the normal tissues, then the possibility arises that this E2DH may be linked with the neoplastic process in some breast tumours containing malignant epithelial cells of a similar type as studied here.
J Steroid Biochem Mol Biol 1992 Sep
PMID:Oestradiol synthesis from oestrone in malignant breast epithelial cells: studies on a high affinity, 80 kDa form of oestradiol dehydrogenase. 152 49

Marked changes in both growth factor and proto-oncogene expression occur due to treatment of hormonally-responsive human cancers with progestins and antiestrogens. In human endometrial cancer cell lines the antiproliferative effects of progestins and antiestrogens in a particular cell line appear to be associated with similar effects on growth factor and/or proto-oncogene expression. This suggests that although these compounds initially interact with different steroid hormone receptors, the molecular mechanisms of their growth inhibition may be essentially similar. In the case of human breast cancer cell lines, however, the effects of progestins and antiestrogens on gene regulation are often different, suggesting that the molecular mechanisms of progestin and antiestrogen growth inhibition may be essentially dissimilar.
J Steroid Biochem Mol Biol 1992 Sep
PMID:Mechanisms of growth inhibition by antiestrogens and progestins in human breast and endometrial cancer cells. 152 52

Patients (186) with locally advanced or metastatic breast cancer were treated with the aromatase inhibitor 4-hydroxyandrostenedione given parenterally at 3 different doses. 21% of patients responded to treatment, 93% of objective responders whose oestrogen receptor (ER) status was known had ER positive tumours. The drug was well-tolerated particularly at a dose of 250 mg i.m. every fortnight. At this dose, only 4/96 (4%) patients had to discontinue treatment. We conclude that 4-hydroxyandrostenedione is a well-tolerated form of endocrine treatment for postmenopausal patients with breast cancer.
J Steroid Biochem Mol Biol 1992 Sep
PMID:4-Hydroxyandrostenedione treatment for postmenopausal patients with breast cancer. 152 56


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