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)

Prolidase [EC 3.4.13.9] plays an important role in the recycling of proline for collagen synthesis and cell growth. The increase in the enzyme activity is correlated with the increased intensity of collagen turnover, thus reflecting the intensity of collagen metabolism. Since estrogens alter collagen metabolism, it can be assumed that the changes may be reflected by prolidase activity. The effects of estrogen and antiestrogen (tamoxifen on the prolidase and collagenase activities and collagen biosynthesis) were measured in the estrogen-receptor (ER)-positive breast cancer cell line. Estradiol stimulated collagen biosynthesis and extracellular prolidase and collagenase activities in cultured MCF-7 cells without an effect on collagen accumulation in the extracellular matrix produced by these cells. On the other hand, tamoxifen inhibited the estrogen-dependent stimulatory effect on collagen biosynthesis but did not inhibit the stimulatory effect of estrogen on prolidase and collagenase activities. The inhibitory effect of tamoxifen on estrogen-dependent stimulation of collagen synthesis in MCF-7 cells and lack of its effect on estrogen-dependent stimulation of prolidase and collagenase activities suggest that both processes (collagen synthesis and degradation) are independently regulated in MCF-7 cells, possibly through antagonist, agonist and other estrogen receptor-independent actions of tamoxifen. Increased extracellular prolidase activity in estrogen-stimulated MCF-7 cells indicates potential diagnostic value of tissue prolidase in determining the ER status of breast cancer.
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PMID:Estrogen-dependent regulation of prolidase activity in breast cancer MCF-7 cells. 1045 8

Although prolidase [EC 3.4.13.9] is found in normal cells, substantially increased levels are found in some neoplastic tissues. Because prolidase possesses the ability to hydrolyse imido bonds of various low molecular weight compounds coupled to L-proline, we hypothesized that coupling of L-proline through an imido bond to anticancer drugs might create prodrugs which would be locally activated by tumour-associated prolidase and consequently would be less toxic to normal cells that evoke lower prolidase activity. To test this concept we have synthesized a conjugate of chlorambucil-proline (CH-pro) as a possible prodrug. Treatment of this prodrug with prolidase generated the L-proline and the free drug, demonstrating its substrate susceptibility to prolidase. We have compared several aspects of biological actions of chlorambucil (CH) and its prodrug in breast cancer MCF-7 cells. IC50 values for chlorambucil and for CH-pro in DNA synthesis were found to be 54 and 16 microM, respectively. CH-pro also exhibited a lesser ability to inhibit collagen biosynthesis in breast cancer MCF-7 cells compared to the free drug. The IC50 values for chlorambucil and for CH-pro in collagen biosynthesis were found to be about 32 and 80 microM, respectively. This suggests that the targeting of prolidase may serve as a potential strategy for converting antineoplastic prodrugs.
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PMID:Prolidase-activated prodrug for cancer chemotherapy cytotoxic activity of proline analogue of chlorambucil in breast cancer MCF-7 cells. 1120 51

We compared the effects of different concentrations of raloxifene (1, 4 and 10 microM) on collagen biosynthesis, gelatinolytic and prolidase activities and matrix metalloproteinase (MMP) expression (MMP-2 and MMP-9) in estradiol-stimulated (2 nM) breast cancer MCF-7 cells. Raloxifene inhibited in a dose-dependent manner the proliferation of MCF-7 cells, independently of the presence or absence of estradiol in the growth medium. Raloxifene at concentrations of 1 microM and 4 microM inhibited collagen biosynthesis by about 10-fold and prolidase activity by about 50%, while at a concentration of 10 microM it inhibited these processes by only about 25%. This phenomenon was accompanied by differences in gelatinolytic activity and MMP (MMP-2 and MMP-9) expression as demonstrated by zymography and Western immunoblot analysis, respectively. In estrogen-stimulated MCF-7 cells, cultured in the presence of 1 microM raloxifene, a dramatic increase in the activity of both collagenases was found. In contrast, addition of raloxifene at a concentration of 10 microM to the medium of the cells resulted in restoration of gelatinolytic activity to that found in control cells. Similarly, but at both doses (1 and 10 microM), raloxifene was able to reduce MMP-2 expression in the cells. However, when used alone (without estradiol) a concentration of 1 microM raloxifene strongly stimulated MMP-2 expression, while at a concentration of 10 microM the effect was not observed. In the case of MMP-9, only trace amounts of this gelatinase were detected, although in contrast to MMP-2, an increase in its expression was noticed at a concentration of 10 microM raloxifene. The data raise the possibility that in estrogen-stimulated MCF-7 cells, raloxifene at low concentrations (1 and 4 microM) evokes antiestrogenic effect on collagen biosynthesis and prolidase activity on the one hand, and an estrogenic effect on gelatinolytic activity on the other, while at higher concentrations (about 10 microM) it evokes an estrogenic effect on collagen biosynthesis and prolidase activity, and an antiestrogenic effect on gelatinolytic activity. Our data suggest that the effects of raloxifene on collagen synthesis, prolidase and metalloproteinase activities in breast cancer may explain its role in the prevention of breast cancer development.
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PMID:Estrogenic and antiestrogenic effects of raloxifene on collagen metabolism in breast cancer MCF-7 cells. 1144 35

Although prolidase [E.C.3.4.13.9] is found in normal cells, substantially increased levels are found in some neoplastic tissues. Prolidase evokes the ability to hydrolyse the imido-bond of various low molecular weight compounds coupled to L-proline. The synthesis of three proline analogues of anthraquinone-2-carboxylic acid (1-3) has been performed. Treatment of these prodrugs with prolidase generated L-proline and the free drug, demonstrating their substrate susceptibility prolidase. The concentrations of 1, 2 and 3 needed to inhibit [1H]thymidine incorporation into DNA by 50% (IC50) in breast cancer MCF-7 cells were found to be 185 +/- 5 microM, 107 +/- 6 microM and 87 +/- 6 microM, respectively, suggesting a lower cytotoxic potency of these compounds compared to Hoechst 33228 (IC50 = 55 +/- 6 microM).
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PMID:Cytotoxicity activity of L-proline analogues of anthraquinone-2-carboxylic acid in breast cancer MCF-7 cells. 1182 Jun 11

Prolidase [E.C.3.4.13.9] is ubiquitously distributed cytosolic egzopeptidase that is known to cleave imido-bond of some low molecular weight compounds coupled to L-proline. Previously we have found that conjugation of antineoplastic drug--melphalan (Mel) with proline (pro) through imido-bond resulted in formation of a good substrate for purified prolidase. Cytosolic location of prolidase in neoplastic cells suggests that proline analogue of melphalan (Mel-pro) may serve as a prolidase convertable pro-drug. We have compared several aspects of pharmacologic actions of Mel and Mel-pro in breast cancer MCF-7 cells. It has been found that Mel-pro is more effectively transported into the MCF-7 cells, evokes higher cytotoxicity, lower antimitotic activity and collagen-inhibiting activity, compared to Mel. The results suggest that targeting of prolidase as a pro-drug-converting enzyme may serve as a potential strategy in pharmacotherapy of breast cancer.
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PMID:Proline analogue of melphalan as a prolidase-convertible pro-drug in breast cancer MCF-7 cells. 1182 Jun 12

Proline analogue of melphalan (Mel-pro) was synthesized as a prodrug susceptible to the action of ubiquitously distributed, cytosolic imidodipeptidase-prolidase [E.C.3.4.13.9]. Conjugation of melphalan (Mel) with proline (Pro) through imido-bond resulted in formation of a good substrate for prolidase. Cytosolic location of prolidase in neoplastic cell suggests that proline analogue of melphalan (Mel-pro) may serve as a prolidase convertible prodrug. We have compared several aspects of pharmacologic actions of Mel and Mel-pro in estrogen-independent breast cancer MDA-MB 231 cells. It has been found that Mel-pro is more effectively transported into the MDA-MB 231 cells, evokes higher cytotoxicity, similar inhibitory effect on DNA synthesis, lower inhibitory effect on collagen biosynthesis and reduces IGF-I receptor and MAPkinase expression in MDA-MB 231 cells, compared to Mel. The results suggest that targeting of prolidase as a Mel-pro-converting enzyme may serve as a potential strategy in pharmacotherapy of breast cancer.
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PMID:Proline analogue of melphalan as a prodrug susceptible to the action of prolidase in breast cancer MDA-MB 231 cells. 1457 62

A novel amidine analogue of chlorambucil-N-(2-(4-(4-bis(2-chloroethyl)aminophenyl)butyryl)aminoethyl)-5-(4-amidinophenyl)-2-furancarboxamide hydrochloride (AB(1)) and the parent drug were compared for their effects on collagen and DNA biosynthesis in breast cancer MCF-7 cells. IC(50) values for chlorambucil and AB(1) for collagen biosynthesis were found to be about 33 and 13 microM, respectively. The greater potency of AB(1) to suppress collagen synthesis was found to be accompanied by a stronger compared with chlorambucil inhibition of prolidase activity and expression. The phenomenon was related to inhibition of beta(1)-integrin and IGF-I receptor-mediated signaling caused by this compound. The expression of beta(1)-integrin receptor, as well as Src, son of sevenless protein (SOS) and phosphorylated mitogen activated protein (MAP) kinases (MAPK), extracellular-signal-regulated kinase 1 (ERK(1)) and kinase 2 (ERK(2)) but not focal adhesion kinase pp125(FAK) (FAK), Shc, and Grb-2 was significantly decreased in cells incubated for 24 h with 10 microM AB(1) compared to the control, whereas in the same conditions chlorambucil did not evoke any changes in expression of all these signaling proteins, as shown by Western immunoblot analysis. Furthermore, AB(1) induced a stronger down-regulation of the expression of IGF-I receptor and evoked a higher antiproliferative effect. During 12 and 24 h of incubation AB(1) decreased DNA biosynthesis by about 33 % and 51 % of the control, whereas chlorambucil decreased it by about 19 % and 35 %, respectively. These data suggest that the amidine analogue of chlorambucil is a stronger inhibitor of protein and DNA synthesis in MCF-7 cells than is the parent drug.
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PMID:Amidine analogue of chlorambucil is a stronger inhibitor of protein and DNA synthesis in breast cancer MCF-7 cells than is the parent drug. 1517 51

Proline analogue of melphalan (Mel-pro) is one of the pro-drugs activated by prolidase, cytoplasmic imidodipeptidase highly expressed in some neoplastic tissues. In order to limit the action of prolidase on the pro-drug in normal cells, prolidase inhibitor, acetylsalicylic acid (ASA), was tested in fibroblasts (showing average prolidase activity for normal cells) and in MDA-MB 231 breast cancer cells (showing elevated activity of the enzyme). The effect of Mel-pro in the presence and absence of ASA on prolidase activity (colorimetric assay), DNA biosynthesis (3H-thymidine incorporation assay), cytotoxicity (tetrazoline assay) and ability to penetrate cell membrane (thin layer chromatography) in both type of cells was measured. It has been found that 5 mM ASA significantly decreased conversion of Mel-pro to Mel in cultured fibroblasts as well as it decreased cytotoxicity and the effect of this drug on DNA synthesis. In contrast, 5 mM ASA had relatively lower effect on the conversion of Mel-pro into Mel in MDA-MB 231 cells as well it had little effect on Mel-pro-induced inhibition of DNA synthesis and cell death. It suggests that ASA may serve as an inhibitor of prolidase-convertible pro-drugs in normal cells.
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PMID:Acetylsalicylic acid as a potential regulator of prolidase-convertible pro-drugs in control and neoplastic cells. 1533 32

A novel amidine analogue of melphalan (AB4) was compared to its parent drug, melphalan in respect to cytotoxicity, DNA and collagen biosynthesis in MDA-MB-231 and MCF-7 human breast cancer cells. It was found that AB4 was more active inhibitor of DNA and collagen synthesis as well more cytotoxic agent than melphalan. The topoisomerase I/II inhibition assay indicated that AB4 is a potent catalytic inhibitor of topoisomerase II. Data from the ethidium displacement assay showed that AB4 intercalated into the minor-groove at AT sequences of DNA. The greater potency of AB4 to suppress collagen synthesis was found to be accompanied by a stronger inhibition of prolidase activity and expression compared to melphalan. The phenomenon was related to the inhibition of beta(1)-integrin and IGF-I receptor mediated signaling caused by AB4. The expression of beta(1)-integrin receptor, as well as Sos-1 and phosphorylated MAPK, ERK(1) and ERK(2) but not FAK, Shc, and Grb-2 was significantly decreased in cells incubated for 24h with 20 microM AB4 compared to the control, not treated cells, whereas in the same conditions melphalan did not evoke any changes in expression of all these signaling proteins, as shown by Western immunoblot analysis. These results indicate the amidine analogue of melphalan, AB4 represent multifunctional inhibitor of breast cancer cells growth and metabolism.
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PMID:Novel amidine analogue of melphalan as a specific multifunctional inhibitor of growth and metabolism of human breast cancer cells. 1673 Jun 67

Adherent interactions between integrins and extracellular matrix (ECM) proteins play an important role in tumorigenicity and invasiveness. The major component of ECM is collagen that plays a central role in the interaction with integrins. The expression of certain collagenases (gelatinases) by tumour cells is one of the characteristic features of the so-called metastatic phenotype, presumably by breaking down ECM barriers as well by altering the ECM-cell interaction. Although extracellular collagenases initiate the breakdown of collagen, the final step of collagen degradation is catalysed by intracellular prolidase. Collagen deposition, gelatinolytic and prolidase activities, expression of beta(1)-integrin receptor and their possible relationships were studied in seven operable breast cancer cases. In breast cancer tissue, we have found significant decrease in the amount of collagen. The decrease in collagen deposition in breast cancer tissue was accompanied by increase in the tissue gelatinolytic and prolidase activities. Simultaneously, a slight decrease in the expression of beta(1)-integrin receptor in breast cancer tissue was observed. These results suggest that alteration in collagen metabolism in breast cancer tissue may reflect tissue remodelling, characteristic for invasive phenotype of cancer cells. Increased gelatinolytic and prolidase activities in breast cancer tissue may enhance stromal matrix degradation and thus may promote metastatic dissemination. On the basis of the data, it seems that compounds endowed with gelatinolytic and prolidase inhibitory activities may be considered as a potential drug candidates for breast cancer therapy.
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PMID:Enhanced prolidase activity and decreased collagen content in breast cancer tissue. 1687 94


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