Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prostatic secretory and basal or stem cells were isolated from rat ventral prostate lobes by collagenase dispersion and density centrifugation in a Percoll gradient. The membrane-bound adenylyl cyclase of secretory cells could be activated in a dose-dependent manner by vasoactive intestinal peptide (VIP ED50 10(-7)M) but not thyrotropin-releasing hormone (TRH). Conversely, only TRH could significantly stimulate the adenylyl cyclase in basal cell membranes (ED50 5 X 10(-7). In two separate studies enzyme activity was stimulated seven- and 13-fold by this peptide. This action of TRH on prostatic basal cells supports previous reports that high levels of immunologically active TRH have been found in prostate tissue and that TRH stimulates the growth of prostatic cancer cells in vitro.
 ...
PMID:Thyrotropin-releasing hormone (TRH) activates the adenylyl cyclase of nonsecretory cells in the rat ventral prostate. 643 3

Electrophoresis and ion-exchange column chromatography were used to separate the wide varieties of acid phosphatases with different biological and clinical significance. Band 0 was very strong in ascitic cells with many autophagic vacuoles, indicating a role in autophagic function. Band 1 was a membrane-bound acid phosphatase, seen mainly in the microsomal fraction. Band 3 was the major lysosomal acid phosphatase of all nonprostatic tissues. Bands 2 and 4 were antigenically identical to each other, and were observed in unusually high amounts in the prostate. The different electrophoretic mobility between bands 2 and 4 was due to their carbohydrate content. Band 5 was a characteristic enzyme of the osteoclast. The tartrate-sensitive enzymes included bands 0 through 4. Only band 5 was tartrate resistant. The tartrate-resistant acid phosphatase of erythrocytes was not detected by the electrophoresis method. Clinical applications were seen for both bands 2 and 5. Band 2 was a secretory enzyme, normally secreted into the seminal plasma. Band 2 was absorbed into the blood circulation in some prostatic cancer patients. A small amount of bands 2 and 4 was observed in nonprostatic tissues. The diagnostic value of band 2 resulted from its extremely high concentration in the prostate. Band 5 was not observed in the normal prostate. A high concentration of band 5 was observed in hairy cells, Gaucher cells, and osteoclasts. The serum level of band 5b was an indicator of osteoclastic activity in the bone. Elevation of band 5b in serum was observed in normal children during physiological bone growth, in Gaucher's disease, and in malignancies metastasized to bone.
 ...
PMID:Comparison of prostatic and nonprostatic acid phosphatase. 695 21

To determine the relative expression of distinct mucin genes in normal and neoplastic tissue, antibodies and cDNA probes that recognize the core tandem repeat sequences of membrane-bound (MUC1) and secreted (MUC2 and MUC3) mucins were used for immunohistochemical and RNA Northern and slot-blot analysis. MUC1 mRNA was detected in all epithelial tissues tested. MUC1 core peptide, recognized by monoclonal antibodies 139H2 and DF3, was highly expressed on apical membranes of bronchus, breast, salivary gland, pancreas, prostate, and uterus, and was sparsely expressed in gastric surface cells, gallbladder, small intestine, and colonic epithelium. In contrast, MUC2 and MUC3 gene expression was primarily restricted to the intestinal tract. MUC2 mRNA was highly expressed in normal jejunum, ileum, and colon, compared with very low levels in normal bronchus and gallbladder. MUC3 mRNA was highly expressed in normal jejunum, ileum, colon, and gallbladder. Immunohistochemical studies using antibodies against synthetic MUC2 (anti-MRP) and MUC3 (anti-M3P) peptides indicate that MUC2- and MUC3-producing cells in the gastrointestinal tract are distinct. Goblet cells of the small intestine and colon reacted strongly with anti-MRP, whereas M3P reactivity was restricted to columnar cells of small intestinal villi, surface colonic epithelium, and gallbladder. Mucin protein epitopes and mRNA levels were frequently altered in adenocarcinomas compared to corresponding normal tissues. Alterations included increased expression, aberrant expression, and, less frequently, loss of expression. Increased MUC1 immunoreactivity was observed in most adenocarcinomas of the breast, lung, stomach, pancreas, prostate, and ovary. In addition, with the exception of prostate cancer, focal aberrant expression of MUC2 and MUC3 epitopes was frequently observed. Increased MUC1, MUC2, and MUC3 epitopes were present in colon adenocarcinomas of all histological subtypes, with the greatest increase of MUC2 epitopes observed in colloid (mucinous) colon cancers. MUC2 or MUC3 mRNA levels were increased in colloid colon cancer compared with normal colon, however in well- and moderately well-differentiated colon cancers MUC1, 2 and 3 mRNA levels were decreased. Compared with corresponding normal tissue, MUC1 mRNA levels were increased in breast cancer and well-differentiated lung cancers, and MUC3 mRNA was increased in gastric adenocarcinomas. Normal stomach lacked both MUC2 and MUC3 immunoreactivity and mRNA, however, MUC2 and MUC3 proteins and mRNA were highly expressed in gastric intestinal metaplasia. In conclusion, mucin genes are independently regulated and their expression is organ- and cell type-specific. Furthermore, neoplastic transformation is associated with dys-regulated expression of both membrane-bound and secreted mucin core protein epitopes and may be due to altered mucin mRNA levels and/or altered mucin glycosylation.
 ...
PMID:Heterogeneity of mucin gene expression in normal and neoplastic tissues. 767 77

Work to date has identified prostate-specific membrane antigen (PSMA) as a membrane-bound glycoprotein with high specificity for prostatic epithelial cells. PSMA reacts with the monoclonal antibody 7E11.C5, which is present in serum, seminal fluid, and prostatic epithelial cells, and is increased in its expression in the presence of a hormone refractory state associated with prostatic cancer. This report confirms these results and further documents the presence of the monoclonal antibody 3F5.4G6, which reacts with the extracellular domain of PSMA. This region of PSMA is also an element present in a truncated version of the protein, so-called PSM'. Immune precipitation with either 7E11.C5 or 3F5.4G6 yields an isolated protein species that are reactive with the reciprocal antibody in Western blot analysis. Thus, 3F5.4G6 recognizes the same PSMA protein as does 7E11.C5, but at different epitopes on essentially opposite ends of the molecule. These two antibodies are well suited for use in a sandwich immunoassay, either one as a capture or detection antibody. Current work on this is underway. This report also confirms that 7E11.C5 Western blots for PSMA are negative with normal human brain tissue. The monoclonal antibody 9H10 does not react with 3F5.4G6 or with 7E11.C5 in studies conducted herein. Moreover, 3F5.4G6 reacts with PSMA found in the LNCaP cell line, but not DU-145 or PC3, which lack PSMA.
 ...
PMID:Measurement of prostate-specific membrane antigen in the serum with a new antibody. 860 2

LNCaP, DU145, and PC3 prostate carcinoma cells secrete the 27-kDa soluble Fas ligand (sFasL) into their local environment. sFasL arises from the 40-kDa membrane-bound form (mFasL), which can be found on the cell surface in the LNCaP line, as demonstrated by monoclonal antibody staining. mFasL was also found in extracts of all three cell lines, as demonstrated by Western blotting. FasL mRNA was detected not only in the cell lines, but in the normal prostate as well. sFasL protein could also be detected immunohistochemically in prostate secretions and in human semen. Cleavage of mFasL to sFasL could be inhibited by several matrix metalloprotease inhibitors without a change in the cellular levels of FasL. Prostate-derived sFasL is biologically active, as demonstrated by its induction of apoptosis in Fas-positive Ramos cells, which was detected by terminal deoxynucleotidyl transferase-mediated nick end labeling assay. Mitoxantrone induces cellular apoptosis in all three prostate cancer cell lines. Mitoxantrone treatment and doxorubicin treatment also cause up-regulation of Fas, the cell surface receptor for FasL, in LNCaP cells, but not in DU145 or PC3 cells. Furthermore, the up-regulation of Fas expression by mitoxantrone at a high concentration was potentiated by hydrocortisone. When FasL interacts with its Fas, the Fas-bearing cell undergoes apoptosis. When LNCaP cells were treated with mitoxantrone and incubated with an anti-FasL monoclonal antibody, apoptosis was partially blocked. This not only further suggests that the sFasL is biologically active, but that the up-regulation of Fas in the presence of sFasL accounts, in part, for the cytotoxicity of mitoxantrone.
 ...
PMID:Fas ligand is constitutively secreted by prostate cancer cells in vitro. 967 59

Analogs of geranylgeranyl diphosphate (GGdP) have been demonstrated to inhibit the geranylgeranylation of proteins, producing cytotoxic activity in human prostate cancer cells. A detailed study is reported on the programmed cell death in vitro of human exocrine pancreas cancer cells (MIA PaCa-2) induced by the most active compound of this series of geranylgeranylation inhibitors, the dipotassium salt of (E,E,E)[2-oxo-2-[[(3,7,11,15-tetramethyl-2, 6,10,14-hexadecatetraenyl)-oxy]amino]ethyl] phosphonic acid (BAL 9504), using transmission and scanning electron microscopy (SEM). The results show that, after 72 h of treatment with BAL 9504, 25 microM, most MIA PaCa-2 cells display the typical morphological features of apoptosis, including condensation of nuclear chromatin, dilation of endoplasmic reticulum, and fragmentation of both nucleus and cytoplasm, giving rise to small membrane-bound vesicles (apoptotic bodies); surface protrusions and blebs are well demonstrated by SEM. The electrophoresis showed the presence of various bands corresponding to fragmented DNA of 180 base pairs, or multiples of this length, thus indicating that BAL 9504 effectively induces apoptosis. The present study provides the first evidence that inhibition of protein geranylgeranylation produces apoptosis in human MIA PaCa-2 exocrine pancreas cancer cells.
 ...
PMID:Ultrastructural and biochemical evidence of apoptosis induced by a novel inhibitor of protein geranylgeranylation in human MIA PaCa-2 pancreatic cancer cells. 979 6

A novel monoclonal antibody has been developed that reacts strongly with human prostatic cancer, especially tumors of high grade. This antibody (7E11C-5) is currently in Phase 3 trials as an imaging agent for metastatic disease. We have cloned the gene that encodes the antigen that is recognized by the 7E11C-5 monoclonal antibody and have designated this unique protein prostate-specific membrane (PSM) antigen. PSM antigen is a putative class II transmembranous glycoprotein exhibiting a molecular size of Mr 94,000. Functionally, class II membrane proteins serve as transport or binding proteins or have hydrolytic activity. Preliminary studies have demonstrated binding of pteroylmonoglutamate (folate) to membrane fractions that also cross-reacted with the PSM monoclonal antibody. We observed substantial carboxypeptidase activity as folate hydrolase associated with PSM antigen. The purpose of our study was to demonstrate that human prostatic carcinoma cells expressing PSM antigen exhibit folate hydrolase activity using methotrexate triglutamate (MTXGlu3) and pteroylpentaglutamate (PteGlu5) as substrates. Isolated membrane fractions from four human prostate cancer cell lines (LNCaP, PC-3, TSU-Prl, and Duke-145) were examined for folate hydrolase activity using capillary electrophoresis. After timed incubations at various pH ranges and in the presence and absence of thiol reagents, separation of pteroyl(glutamate)n derivatives was achieved with an electrolyte of sodium borate and SDS, while absorbance was monitored at 300 nm. The results demonstrate clearly that LNCaP cells, which highly express PSM, hydrolyze gamma-glutamyl linkages of MTXGlu3. The membrane-bound enzyme is an exopeptidase, because it progressively liberates glutamates from MTXGlu3 and PteGlu5 with accumulation of MTX and PteGlu1, respectively. The semipurified enzyme has a broad activity from pH 2.5 to 9.5 and exhibits activity maxima at pH 5 and 8. Enzymatic activity is maintained in the presence of reduced glutathione, homocysteine, and p-hydroxymercuribenzoate (0.05-0.5 mm) but was inhibited weakly by DTT (>/=0.2 mm). By contrast to LNCaP cell membranes, membranes isolated from other human prostate adenocarcinoma cells (PC-3, Duke-145, and TSU-Pr1) did not exhibit comparable hydrolase activity, nor did they react with 7E11-C5 monoclonal antibody. After transfection of PC-3 cells with a full-length 2.65-kb PSM cDNA subcloned into a pREP7 eukaryotic expression vector, non-PSM antigen-expressing PC-3 cells developed immunoreactivity to 7E11-C5 monoclonal antibody and demonstrated folate hydrolase activities and optimum pH activity profiles identical to those of LNCaP cells. The membrane-bound enzymes from both LNCaP- and PC-3-transfected cells also have a capacity to hydrolyze an alpha-linked glutamyl moiety from N-acetyl-alpha-aspartylglutamate. We have identified that PSM antigen is a pteroyl poly-gamma-glutamyl carboxypeptidase (folate hydrolase) and is expressed strongly in human prostate cancer. Cancer cells that express this enzyme are resistant to methotrexate therapy. Those developing future therapeutic strategies in the treatment of prostate cancer that utilize folate antagonists need to consider this mechanism of resistance.
 ...
PMID:Prostate-specific membrane antigen: a novel folate hydrolase in human prostatic carcinoma cells. 981 19

Previous work from this laboratory suggests an activation of the sphingomyelin cycle as a mechanism for growth inhibition with the incorporation of beta-sitosterol (SIT) into human prostate cancer LNCaP cells. In the present study we examined two key enzymes that have been shown to play a role in the sphingomyelin cycle. Dietary sterols (SIT and cholesterol) were compared for their effect on LNCaP cell growth, phospholipase D (PLD) activity, and protein phosphatase 2A (PP 2A) activity and expression. PP 2A has been suggested as a direct in vitro target of ceramide action on cell growth and apoptosis. Ceramide also inhibits phorbol myristate acetate-stimulated PLD. SIT (16 microM) increased PP 2A activity by 50% compared with cholesterol treatment in LNCaP prostate cells; however, SIT did not alter protein levels of PP 2A. There was an increase in PLD activity in the presence of phorbol myristate acetate in cells supplemented with 16 microM SIT compared with those supplemented with cholesterol after five days of treatment. The present study suggests that the activation of PP 2A added support to the role of the activation of the sphingomyelin cycle by SIT treatment. However, the increase in PLD activity, which was modest but significant, with SIT supplementation suggests that this pathway may be modulated by other mechanisms. This includes the incorporation of SIT into cell membranes that may alter fluidity and, thus, influence the activation of membrane-bound enzymes such as PLD.
 ...
PMID:Effect of beta-sitosterol, a plant sterol, on growth, protein phosphatase 2A, and phospholipase D in LNCaP cells. 1079 19

Previously, we reported that 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced apoptosis of LNCaP human prostate cancer cells was accompanied by prolonged translocation of protein kinase C (PKC)alpha to non-nuclear membranes and that TPA-resistant LNCaP cells had down-regulated PKCalpha. Here we show that 10 nM bryostatin 1 induced transient membrane translocation and down-regulation of PKCalpha, prolonged translocation of PKCdelta and epsilon to non-nuclear membranes, and did not induce cell death but blocked TPA-induced apoptosis. To test the hypothesis that inhibition of TPA-induced apoptosis by bryostatin 1 was due to down-regulation of PKCalpha, we inducibly overexpressed PKCalpha in LNCaP cells. Overexpression of PKCalpha alone did not induce apoptosis, even in clones that contained much more membrane-bound, active PKCalpha than was observed in TPA-treated untransfected LNCaP cells. However, the addition of 10 nM bryostatin 1 to PKCalpha-overexpressing LNCaP cells did not yield down-regulation of PKCalpha and induced extensive apoptosis. Immunoblot analysis revealed that TPA induced prolonged hyperphosphorylation of Raf-1 and activation of extracellular-regulated/mitogen-activated protein kinases 1 and 2 in untransfected LNCaP cells, as did bryostatin 1 in PKCalpha-overexpressing cells. On the other hand, bryostatin 1 induced only transient hyperphosphorylation of Raf-1 and activation of extracellular-regulated/mitogen-activated protein kinases 1 and 2 in untransfected LNCaP cells. These results confirm a role of prolonged membrane-associated PKCalpha in PKC activator-mediated LNCaP apoptosis and suggest involvement of the mitogen-activated protein kinase pathway.
 ...
PMID:Bryostatin 1 induces prolonged activation of extracellular regulated protein kinases in and apoptosis of LNCaP human prostate cancer cells overexpressing protein kinase calpha. 1082 94

Several laboratories have attempted with little success to induce Fas-mediated apoptosis in prostate cancer (PCa) cells, using different external Fas agonists, i.e., anti-Fas antibodies and membrane-bound FasL. The present study confirms these earlier results using the anti-Fas antibody CH-11 in five human PCa cell lines (PPC-1, LNCaP, PC-3, TSU-Pr1, and DU145). However, intracellular murine FasL expression induced Fas-mediated apoptosis in all CH-11-resistant cell lines. Adenovirus (AdGFPFasL(TET)) was used to deliver a Murine FasL-GFP fusion gene into human PCa cells resulting in 70-98% apoptosis at 48 h as determined by the MTS assay. DU145 and PPC-1 cells treated with AdGFPFasL(TET) stained positive for the TUNEL assay, indicating that cell death was via apoptosis. Using immunofluorescent microscopy, Fas and GFPFasL colocalized to the same intracellular compartment. The anti-Fas neutralizing antibody ZB-4 was unable to block AdGFPFasL(TET)-mediated cell death, suggesting that intracellular FasL may ligate Fas within the Golgi and/or endoplasmic reticulum. This is the first evidence suggesting that these two molecules interact prior to cell surface presentation. Collectively, these findings indicate that intracellular GFPFasL expression is superior to CH-11 at inducing Fas-mediated apoptosis in human PCa cells and may allow use of AdGFPFasL(TET) for PCa gene therapy.
 ...
PMID:Intracellular Fas ligand expression causes Fas-mediated apoptosis in human prostate cancer cells resistant to monoclonal antibody-induced apoptosis. 1102 Mar 50


1 2 3 4 5 6 7 8 Next >>