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PubMed1992

Evidence for an apical sorting signal on the ectodomain of human aminopeptidase N.

In polarized epithelial cells aminopeptidase N is targeted to the apical membrane. The aim of this study was to determine whether a sorting signal is necessary for its correct transport to the apical membrane and, if so, to localize this sorting signal to one of the domains of the transmembrane protein. Anchor-minus aminopeptidase N, consisting of the hemagglutinin signal peptide including its cleavage site, and the ectoplasmic domain of human aminopeptidase N were stably expressed in Madin-Darby canine kidney cells cultured on polycarbonate filters. By measurement of the enzymatic activity it was found that the anchor-minus aminopeptidase N was secreted in a polarized manner to the apical side. As a reference the secretion of the secretory granule protein, cystatin C, was likewise studied. Cystatin C was found to be secreted in a nonpolarized manner to both domains. Our data thus show that human aminopeptidase N carries an apical sorting signal and that it is localized on the ectodomain of the enzyme.

Amino Acid Sequence↗
PubMed1992

Molecular cloning and characterization of onchocystatin, a cysteine proteinase inhibitor of Onchocerca volvulus.

A cDNA clone designated OV7 encodes a polypeptide that corresponds to a highly antigenic Onchocerca volvulus protein. OV7 has significant amino acid sequence homology to the cystatin superfamily of cysteine proteinase inhibitors. In this report we establish that the OV7 recombinant protein is active as a cysteine proteinase inhibitor, and we have named it onchocystatin. It contains a cystatin-like domain that inhibits the activity of cysteine proteinases at physiological concentrations. Recombinant glutathione S-transferase-OV7 (GST-OV7, 1 microM) and maltose-binding protein-OV7 (MBP-OV7, 4 microM) fusion polypeptides inhibit 50% of the enzymatic activity of the bovine cysteine proteinase cathepsin B. Neither fusion polypeptide inhibits serine or metalloproteinases activity. The Ki for GST-OV7 fusion polypeptide is 170 nM for cathepsin B and 70 pM or 25 nM for cysteine proteinases purified from a protozoan parasite Entamoeba histolytica or the free living nematode Caenorhabditis elegans, respectively. The 5' end of the OV7 clone was isolated by polymerase chain reaction and sequenced, thus extending the previous cDNA clone to 736 base pairs. This represents the complete coding sequence of the mature onchocystatin (130 amino acids). A hydrophobic leader sequence of 32 amino acids was found, indicating a possible extracellular function of the onchocerca cysteine proteinase inhibitor.

Amino Acid Sequence↗
PubMed2003

[Assessment of age-related changes in parathyroid hormone levels by different methods.].

BACKGROUND: Current assays measuring intact PTH may not only measure the active form, PTH(1-84), but also some large breakdown products, including PTH(7-84). A new method is believed to measure only PTH(1-84). The purpose of this study was to examine whether increases in intact PTH that accompany age, weight and worsening renal function could be related to breakdown products interfering with traditional assays. METHODS: We used data from an ongoing cross-sectional study on bone health in 40-85 years old Icelanders. Over a 12 month period, 1096 subjects were invited for a DEXA scan, blood test, height and weight measurements and each subject answered a questionnaire on health and medication. For the current analysis we excluded those who were taking medications affecting bone and mineral metabolism. PTH was measured using PTH elecsys (Roche) and the new PTH cap (Scantibodies). We used kappa statistic to assess agreement with regard to levels above upper reference values for each assay and ANOVA, Pearson's and Spearman's correlation coefficients for other analysis. Women and men were analyzed separately. RESULTS: Of 746 individuals who came for the study, after exclusion, 247 women and 209 men remained for this analysis. PTH was on the average roughly 40% lower with the new PTH cap assay. The correlation between the assays was 0.787 (P<0.001) for women and 0.69 (P<0.001) for men. Kappa statistic was 0.486 (P<0.001) for women and 0.283 (P<0.001) for men, indicating fair to good agreement. PTH elecsys increased with age (P=0.03 and P=0.01 for women and men, respectively) but not PTH cap (P=0.7 and P=0.09 for women and men, respectively). PTH elecsys was positively associated with cystatin C (P<0.05 for both genders), but the correlation between PTH cap and Cystatin C was not statistically significant. The association with body mass index was similar for the two assays (r=0.16 to 0.24, P<0.05) for both genders. CONCLUSIONS: There is a significant difference between these two PTH assays. It is likely that increases in intact PTH observed with age and worsening renal function are related to large breakdown products of PTH whereas the PTH increase seen with higher weight seems to be related to PTH(1-84) itself.

English Abstract↗
PubMed2006

Matrigel influences morphology and cathepsin B distribution of prostate cancer PC3 cells.

Increases in expression and activity of matrix-degrading enzymes such as the cysteine proteinases cathepsins B and L, and abnormal levels of their inhibitors, the cystatins, are associated with tumor cell invasion and metastasis. Environmental conditions have been shown to be causative factors in the development of a metastatic/invasive phenotype. We hypothesized that cell-matrix interactions affect the expression and activity of cathepsins B and L and their inhibitors in the prostate cancer cell lines, PC3 and DU145. To test this possibility, PC3 and DU145 were plated on uncoated surfaces or on surfaces coated with the reconstituted basement membrane, Matrigel. The cells were analyzed for cathepsins B and L immunolocalization, protein expression and activity 48 h after plating. Our data demonstrated that cathepsins B and L displayed a distinct punctate distribution with little co-localization; individual cells displayed a predominant staining for one or the other enzyme. Cathepsin B had a perinuclear distribution in PC3 grown on uncoated surfaces but a more peripheral staining in PC3 plated on Matrigel. Localization of cathepsin L remained predominantly perinuclear regardless of the plating surface. In addition to the translocation of cathepsin B from a perinuclear distribution to the cell periphery, growth of PC3 on Matrigel shifted cathepsin B activity from the cell extract to the media. There were no significant changes in cathepsins B and L immunolocalization or activity in DU145 with regard to plating surfaces. Likewise, the activity of endogenous cysteine proteinase inhibitors (CPIs) and protein expression of cystatin C remained unchanged in both cell lines. In conclusion, the interaction of PC3 prostate cancer cells with extracellular matrix components affects the distribution of cathepsin B protein and activity.

Cathepsin B↗
PubMed2006

[Mycophenolate mofetil in treatment of childhood nephrotic syndrome--preliminary report].

The management of nephrotic syndrome (NS) in children remains a clinical challenge for pediatricians and pediatric nephrologists. Especially, the treatment of patients with steroid-resistant (SR) and steroid-dependent (SD) nephrotic syndrome, because they are at risk for developing complications from prolonged exposure to steroids, CsA and alkylating agents. Mycophenolate mofetil (MMF) is a selective and reversible inhibitor of inosine monophosphate dehydrogenase used above all in transplantology and recently also in patients with nephrotic syndrome. The aim of this study was to tentatively assess the usefulness and the safety of MMF as an immunosuppressive agent in children with steroid-resistant NS, in whom remission was not obtained with previous treatment regimens, and those with steroid-dependent NS, in whom severe adverse reactions were observed in steroid and cyclosporine therapy. The study included 19 children with NS (11 girls, 8 boys) aged 7 to 19.5 years (a mean of 13.5), treated at the Deptartment of Pediatric Nephrology. The duration of disease was from 1 to 16 years (a mean of 9.3). The patients were divided into 3 groups: I--9 children with steroid-dependent NS; II--6 children with steroid-dependent NS and episodes of steroid-resistance; III--4 children with steroid-resistant NS. All patients in groups II and III required multi-drug therapy (prednisone, cyclosporine A, methylprednisolone, chlorambucil, cyclophosphamide) before MMF was introduced. MMF was administered orally: 180-600 mg/m2 body surface/dose, twice daily. The follow-up period lasted for 4 to 16 months (a mean of 7.7). The clinical outcome analysis included decrease or disappearance of proteinuria, clinical improvement and/or possibility of tapering therapy intensity, especially the dosage of steroids and/or CsA. Also, renal function was monitored with serum cystatine C concentration. Particular attention was paid to adverse effects of MMF upon the gastro- intestinal tract and/or opportunistic infections. All medication (apart from MMF) could be discontinued in 4 patients; in 15 cases, prednizone dose was reduced and in 9 cases CsA dose was reduced or discontinued. In group I (SD) steroid treatment could be reduced from a mean prednisone dose of 22.8 to 3.6 mg/m2/48 hours (p=0.018), in groups II and III, in spite of 50 % reduction of a mean prednisone dose, the difference did not reach statistical significance. During MMF therapy Csa treatment could be reduced from a mean CsA dose 4.3 to 2.9 mg/kg/24 hours (p=0.008). Improvement or preservation of stable renal function was observed in all patients--cystatin C levels decreased significantly from a mean 1.35 to 0.96 mg/l (p=0.007). Adverse reaction to MMF (abdominal pain) was observed in 2 patients (nausea, vomiting, diarrhoea in 1, CMV infection in 1). The initial clinical observation of MMF treatment in nephrotic patients shows its best effect in the group of patients with steroid-dependent NS. MMF can safely be used in children with NS. The introduction of MMF allows for reduction of other chronically used medications, especially CsA and steroids.

Adolescent↗
PubMed1986

[Low-molecular cysteine protease inhibitors in the human palatal tonsil].

2 low-molecular cysteine-proteinase inhibitors were purified from human tonsillar tissues: an acid cysteine proteinase inhibitor (ACPI), and a neutral cysteine proteinase inhibitor (NCPI). Their biochemical and immunological characteristics appeared to be identical to those inhibitors which we have identified in other human tissues in previous studies (epidermis and spleen). An immunohistological analysis revealed in tonsillar squamous epithelium a strong and consistent immunoreactivity for both inhibitors. In the tonsillar lymphatic tissue, ACPI-immunoreactivity appeared to be a characteristic mainly of dendritic reticulum cells whereas a prominent NCPI-immunoreactivity was confined mostly for the histiocytic reticulum cells in lymphoid secondary follicles. We also compared the distribution of the 2 immunoreactive inhibitors with the immunohistology as revealed by antisera raised against keratin and muramidase. Limitations of the immunohistochemistry of cysteine proteinase inhibitors are discussed in the light of an extensive trial of various fixation procedures. We deem that proposal of Barrett (1984) for the nomenclature of cysteine proteinase inhibitors is appropriate. According to it the ACPI is the cystatin A, and the NCPI is the cystatin B.

Child↗
PubMed1988

A new purification procedure of human kidney cathepsin H, its properties and kinetic data.

A purification procedure of cathepsin H from human kidney is presented. It includes gel filtration, ion exchange chromatography, and covalent chromatography on thiol Sepharose as an essential step. Purified cathepsin H emerges in an isoelectric focusing gel at pH 6.1 and 6.3. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate shows a molecular mass of about 28 kDa. Less than 20% of the enzyme preparation can be separated into a heavy (24 kDa) and a light chain (4 kDa) after reduction and gel filtration on Sephacryl S-200. The partial amino-acid sequence of human cathepsin H shows its close similarity to rat cathepsin H. Inhibition constants (Ki) of cathepsins H and B with chicken cystatin, two forms of human stefin A, human stefin B, and two forms of human cystatin C are in the range of 10(-9) to 10(-11)M.

Amino Acid Sequence↗
PubMed1986

mRNA levels of cathepsins B and D during myogenesis.

Muscle development is characterized by the fusion of myoblasts to form myotubes and the co-ordinate expression of muscle-specific proteins such as actin, myosin and creatine phosphokinase. Our laboratory has been involved in the study of the role of lysosomal proteinases, namely, cathepsins B, H and L and the endogenous cysteine proteinase inhibitor, cystatin, during muscle differentiation in vitro. Specific activities of the cysteine proteinase in chicken primary cultures and a number of rat myogenic lines increased with the degree of myotube formation. This has suggested that lysosomal proteinases play an important role in myogenesis. We have measured the mRNA levels of two of the lysosomal enzymes, cathepsins B and D. This is advantageous because the presence of the endogenous inhibitor, cystatin, masks the levels of the specific activities of the cysteine proteinases present in the cell. RNA was extracted from developing muscle at three stages of development: proliferating myoblasts, confluent cells, and myotubes. Hybridization of RNA extracted from the L6 myogenic cell line with cathepsin B cDNA showed an increase in the level of cathepsin B mRNA. However, in the L8 rat myogenic line the level decreased after fusion. Cathepsin D mRNA levels remained constant throughout differentiation of the L8 cells. This paper also reports on the characterization of lysosomal proteinases of a newly obtained mouse myogenic line, C2.

Animals↗
PubMed1993

Cysteine proteinases and inhibitors in inflammation: their role in periodontal disease.

Cellular and molecular events during the development of inflammatory disease are accompanied by the release of host lysosomal cysteine proteinases (CPs) affecting not only degradation of matrix proteins but possibly also antigen processing and chemotaxis of neutrophils. Activity measurements of Cat B and Cat L could not be used as an accurate indicator of disease activity in individual patients, although average values were higher in patients with more advanced periodontal inflammation. In contrast, simultaneous decrease of cystatin C and alpha 2-macroglobulin (alpha 2-M) in inflamed gingiva and gingival fluid, respectively, might be useful diagnostic/prognostic factors. While the total and the free form of alpha 2-M in gingival fluid decreased with the progression of the disease, the complexed alpha 2-M form was hardly detectable. This indicates an increased consumption of this inhibitor by various proteinases and clearance of protease: alpha 2-M complexes by macrophages. Elevated serum levels of alpha 2-M were found in patients with more pronounced disease, suggesting a systemic host response. In addition, high levels of stefin A and moderate levels of kininogen were observed in gingival tissue homogenates. Stefin A was also found to play a role in the inhibition of neutrophil chemotaxis. In addition, other proteinases which are released at inflammatory sites from neutrophils, macrophages, lymphocytes, and/or bacteria may degrade the cystatins, thereby further increasing CP activities. Increased CP activity may inactivate serine protease inhibitors, leading to the so-called "proteolytic burst."

Animals↗
PubMed1996

Cerebral amyloid angiopathies.

The cerebral amyloid angiopathies comprise a heterogeneous group of disorders that are characterized clinically by ischaemic and/or haemorrhagic strokes, and histologically by deposition of amyloid in the wall of leptomeningeal and cerebral cortical blood vessels. On the basis of the molecular composition of the amyloid, two forms can be distinguished. Cystatin C amyloid angiopathy is a rare autosomal dominant disorder confined to several families from Iceland. beta-amyloid cerebral amyloid angiopathies may be hereditary or sporadic, and share clinical, pathological and biochemical features with Alzheimer's disease. Both types of vascular amyloid derive from precursor proteins synthesized in situ by astrocytes (cystatin C) or smooth muscle cells (beta-amyloid), and induce progressive degeneration of smooth muscle cells, blood vessel rupture and haemodynamic changes. In recent years, it has been reported that mutations underlying both types of hereditary cerebral amyloid angiopathy directly involve the gene encoding the precursor protein. These findings have increased our understanding of the amyloidogenic mechanisms and allowed preclinical diagnosis. Nevertheless, the aetiopathogenetic factors involved in the more frequent sporadic form of amyloid angiopathy remain unknown.

Animals↗
PubMed1998

Cysteine proteinases in cancer progression and their clinical relevance for prognosis.

Lysosomal cysteine proteinases, also known as cysteine cathepsins (Cats), belong to the papain family of proteinases, and share a similar protein structure and mechanism of action. However, subtle structural differences between these cathepsins, e.g. Cats B, H and L, give rise to potentially important variations in substrate specificity and differences in inhibition by their endogenous inhibitors, the cystatins, stefins and kininogens, under physiological and pathological conditions. Alterations in expression of Cat B and Cat L have been observed at various levels in malignant human tumor tissue compared to normal and benign tissue counterparts. We proposed that an imbalance between cathepsins and cystatins, associated with the metastatic tumor cell phenotype, may facilitate tumor cell invasion and metastasis and be responsible for early relapse of the disease after removal of the primary tumor. The results of our initial investigations on cysteine cathepsins and their endogenous inhibitors in human breast, lung and head and neck carcinomas, as well as in body fluids of melanoma and colorectal carcinoma bearing patients, have indeed shown their high prognostic impact for the survival of these patients.

Animals↗
PubMed1998

Matrix metalloproteinases, but not cathepsins B, H, and L or their inhibitors in peripheral blood of patients with rheumatoid arthritis are potentially useful markers of disease activity.

OBJECTIVE: The clinical activity of rheumatoid arthritis (RA) is not reliably reflected by laboratory measures. Proteolytic enzymes involved in the cascade of joint destruction are potentially useful parameters to monitor the extent of joint inflammation in RA. This study compares the validity of two classes of proteolytic enzymes, matrix metalloproteinases (MMP) and lysosomal cysteine proteinases (cathepsin B, H, and L) as well as their respective inhibitors to serve as parameters of RA disease activity. METHODS: The proteolytic activity of cathepsin B, H, and L was determined by fluorometry in sera of 20 patients with active RA and of 20 healthy donors. In addition, the concentrations of cathepsin B and L as well as of cathepsin inhibitors stefin A, stefin B, and cystatin C were measured by ELISA. The plasma concentrations of MMP-1 (collagenase), MMP-3 (stromelysin), tissue inhibitor of metalloproteinases 1 (TIMP-1), and of MMP-1/TIMP-1 complex (MT complex) were analyzed by ELISA as well. RESULTS: A significant increase of MMP-1, MMP-3, and MT complex was observed in RA plasma, compared to normal controls, whereas TIMP-1 concentrations did not differ. In contrast, neither serum activity nor protein concentration of any of the cathepsins or cathepsin inhibitors were elevated in RA. CONCLUSION: Despite ample evidence in the literature that cathepsin activity contributes to the pathogenesis of inflammatory joint disease, this is not reflected by the conditions in peripheral blood. In contrast to the cysteine proteinases, MMP-1 and MMP-3 as well as MT complex are elevated in RA. In the context of findings in the literature, this stresses the importance of MMP as disease activity markers, compared to cysteine proteinases or their inhibitors.

Aged↗
PubMed1994

Structural characterisation of human stefin A in solution and implications for binding to cysteine proteinases.

Stefin A is a member of the cystatin superfamily of proteins which are tight and reversibly binding inhibitors of the papain-like cysteine proteinases. The 1H-NMR and 15N-NMR resonances of human stefin A have been sequentially assigned using two-dimensional homonuclear and heteronuclear NMR techniques in conjunction with three-dimensional heteronuclear methods. Characteristic sequential and medium range NOE contacts, J constants and hydrogen exchange data have been used to identify the secondary structural elements of the protein which consists of five anti-parallel beta-strands and a single alpha-helix. There is much similarity between the secondary structural features of stefin A and the homologous protein stefin B in its complex with papain [Stubbs, M. T., Laber, B., Bode, W., Huber, R., Jerala, R., Lenarcic, B. & Turk, V. (1990) EMBO. J. 9. 1939-1947] but also some important differences in regions which are fundamental to the binding event. The principal difference is the presence of two conformationally unrestricted regions in stefin A that form two of the components of the tripartite wedge which docks into the active site of the target proteinase. Specifically, these regions are the five N-terminal residues and the second binding loop, which form a turn and a short helix respectively, in the bound conformation of stefin B.

Amino Acid Sequence↗
PubMed2002

Amyloid fibril formation by human stefin B in vitro: immunogold labelling and comparison to stefin A.

The mechanism by which proteins form amyloid fibrils is of high interest to the scientific community as its understanding could resolve questions relevant to conformational diseases. The structural and energetic basis of the process is still largely unknown. The main controversial issue is the co-existence of several protein conformations. Three models for the mechanism of protein fibrillogenesis have been proposed which need to be tested by experiments. In this report, amyloid fibrils grown from human stefin B (type I cystatin) are described. This physiologically relevant protein readily forms fibrils in vitro, in contrast to the homologue--human stefin A--which forms fibrils under extreme conditions only. In order to specifically label stefin B fibrils in vitro, rabbit polyclonal antibody and mouse monoclonal antibody A6/2 against human stefin B were used for immunogold labelling. Samples were examined by transmission electron microscopy. Fibrils of stefin B were strongly labelled using polyclonal antibody and Protein A gold, whereas no positive reaction was observed with monoclonal antibody A6/2.

Amyloid↗
PubMed1999

Analysis of intact proteins from cerebrospinal fluid by matrix-assisted laser desorption/ionization mass spectrometry after two-dimensional liquid-phase electrophoresis.

A novel combination of methods, two-dimensional liquid-phase electrophoresis (2D-LPE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), have been used for the analysis of intact brain-specific proteins in cerebrospinal fluid (CSF). 2D-LPE is especially useful for isolating proteins present in low concentrations in complex biological samples. The proteins are separated in the first dimension by liquid-phase isoelectric focusing (IEF) in the Rotofor cell and in the second dimension by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) in the Preparative cell. The removal of SDS by chloroform/methanol/water, followed by sample preparation with the addition of n-octylglucoside, easily interfaced 2D-LPE with MALDI-TOFMS for analysis of intact proteins. Further characterization by proteolytic digestion is also demonstrated. The knowledge of both the molecular weights of the protein and of the proteolytic fragments obtained by peptide mapping increases specificity for protein identification by searching in protein sequence databases. Two brain-specific proteins in human CSF, cystatin C and transthyretin, were isolated in sufficient quantity for determination of the mass of the whole proteins and their tryptic digest by MALDI-TOFMS. This approach simplified the interface between electrophoresis and MALDI-TOFMS.

Blotting, Western↗
PubMed2001

Advances in the genetics of progressive myoclonus epilepsy.

The genetic progressive myoclonus epilepsies (PMEs) are clinically characterized by the triad of stimulus sensitive myoclonus (segmental lightning like muscular jerks), epilepsy (grand mal and absences) and progressive neurologic deterioration (dementia, ataxia, and various neurologic signs depending on the cause). Etiologically heterogenous, PMEs are rare and mostly autosomal recessive disorders, with the exception of autosomal dominant dentatorubral-pallidoluysian atrophy and mitochondrial encephalomyopathy with ragged red fibers (MERRF). In the last five years, specific mutations have been defined in Lafora disease (gene for laforin or dual specificity phosphatase in 6q24), Unverricht-Lundborg disease (cystatin B in 21q22.3), Jansky-Bielschowsky ceroid lipofuscinoses (CLN2 gene for tripeptidyl peptidase 1 in 11q15), Finnish variant of late infantile ceroid lipofuscinoses (CLN5 gene in 13q21-32 encodes 407 amino acids with two transmembrane helices of unknown function), juvenile ceroid lipofuscinoses or Batten disease (CLN3 gene in 16p encodes 438 amino acid protein of unknown function), a subtype of Batten disease and infantile ceroid lipofuscinoses of the Haltia-Santavuori type (both are caused by mutations in palmitoyl-protein thiosterase gene at 1p32), dentadorubropallidoluysian atrophy (CAG repeats in a gene in 12p13.31) and the mitochondrial syndrome MERRF (tRNA Lys mutation in mitochondrial DNA). In this review, we cover mainly these rapid advances.

Cystatin B↗
PubMed2002

Prediction of pelvic lymph node metastasis by the ratio of cathepsin B to stefin A in patients with prostate carcinoma.

BACKGROUND: Pathologic grade and/or histologic score, extraprostatic extension indicated by invasion of the prostatic capsule, margin, and/or seminal vesicles by prostate cancer cells, serum total prostate-specific antigen (PSA), free PSA, complexed PSA levels and/or their ratios, regional pelvic lymph node metastases, and clinical staging have been used to diagnose and monitor the treatment of prostate carcinoma (PC) patients. The Gleason grading system is also used to grade/score a patient's stage of disease, with lower to higher scores indicating progression of PC. However, Gleason's system cannot be used to distinguish biologically aggressive PCs within a single Gleason score. Our objective was to identify subpopulations (or clones) of aggressive prostate cancers within an individual Gleason score by utilizing biological molecule(s) that also facilitate cancer cell invasion to prostatic stroma and metastasis to the lymph nodes. MATERIALS AND METHODS: Specimens were collected from 97 patients with PC and from 8 patients with benign prostatic hyperplasia. These patients had not been treated with hormonal and/or chemotherapeutic agents before undergoing a prostatectomy at the Minneapolis Veterans Affairs Medical Center. Formalin-fixed, paraffin or paraplast-embedded prostate tissue sections were stained with hematoxylin and eosin for pathologic diagnosis and adjacent sections were stained for for immunohistochemical study. We also collected data on age, race, extraprostatic extension, margin status, seminal vesicle, and lymph node invasion by cancer cells, clinical stage at prostatectomy, and mortality/survival data, including the available presurgery and postsurgery serum total PSA and prostatic acid phosphatase concentrations in patients. Immunohistochemical localization of mouse or rabbit anti-cathepsin B (CB) antibody IgG and mouse antihuman stefin (cystatin) A IgG was quantified using a computer-based image analysis system equipped with Metamorph software. RESULTS: CB and stefin A identified aggressive and less aggressive clones of PCs within an individual Gleason score. Tumors with a Gleason Score of 6 that are similar histologically and morphologically were heterogeneous with respect to the ratios of CB to stefin A (CB > stefin A, CB = stefin A, and CB < stefin A). We also found a significant positive association (P = 0.0066) between ratios of CB and stefin A (CB > stefin A) and the incidence of pelvic lymph node metastases, but not with ratios of CB less than stefin A and/or ratios of CB equal to stefin A. Patients with Gleason 7 PCs had a higher incidence of positive lymph nodes than those with Gleason Score 6 tumors. Our data indicated that mortality rates increased in patients when the ratios of CB were greater than stefin A. CONCLUSIONS: PC within an individual Gleason score is a heterogeneous tumor that contains clones or subpopulations of aggressive and less aggressive tumors that can be defined by the ratios of CB to stefin A. PC with an aggressive clone can be identified when the ratio of CB is greater than that of stefin A. Less aggressive clones are identified when the ratio of CB is less than that of stefin A or when the ratio of CB is equal to that of stefin A. The ratios of CB to stefin A can be used in the differential diagnosis and treatment of patients with PC. This is the first report to identify phenotypes of aggressive and less aggressive PCs within a Gleason score.

Aged↗
PubMed2003

Proteomic analysis of pancreatic ductal carcinoma cells treated with 5-aza-2'-deoxycytidine.

A pancreatic adenocarcinoma cell line (PaCa44), which contains, among other alterations, a methylated p16 promoter, was treated with a chemoterapeutic agent, 5-aza-2'-deoxycytidine (DAC), in order to evaluate the effect of this drug on cell growth and protein expression. Cell proliferation was strongly inhibited by a 24 h DAC treatment and this inhibition lasted for at least 10 days. Master maps of control and treated PaCa44 cells were generated by analysis with the PDQuest software. The comparison between such maps showed up- and downregulation of 45 polypeptide chains, of which 32 were downregulated and 13 upregulated, out of a total of 700 spots detected by a medium-sensitivity stain, micellar Coomassie Brilliant Blue. Fingerprinting by mass spectrometry analysis enabled the identification of 36 of these spots. Among the major changes in DAC-treated cells: cofilin and profilin 1 are silenced; coactosin, peptidyl-propyl cis-trans isomerase A and cystatin B are decreased by 22, 16- and 15-fold, respectively; stress-70 protein, superoxide dismutase and protein disulfide isomerase A3 are increased by 13-, 11-, and 5-fold, respectively. The significance of some of these major changes is discussed.

Actin Depolymerizing Factors↗