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Friedman A, Jain HV. A partial differential equation model of metastasized prostatic cancer. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2013; 10:591-608. [PMID: 23906138 DOI: 10.3934/mbe.2013.10.591] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Biochemically failing metastatic prostate cancer is typically treated with androgen ablation. However, due to the emergence of castration-resistant cells that can survive in low androgen concentrations, such therapy eventually fails. Here, we develop a partial differential equation model of the growth and response to treatment of prostate cancer that has metastasized to the bone. Existence and uniqueness results are derived for the resulting free boundary problem. In particular, existence and uniqueness of solutions for all time are proven for the radially symmetric case. Finally, numerical simulations of a tumor growing in 2-dimensions with radial symmetry are carried in order to evaluate the therapeutic potential of different treatment strategies. These simulations are able to reproduce a variety of clinically observed responses to treatment, and suggest treatment strategies that may result in tumor remission, underscoring our model's potential to make a significant contribution in the field of prostate cancer therapeutics.
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Affiliation(s)
- Avner Friedman
- Department of Mathematics, Ohio State University, Columbus, OH 43210, USA.
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Vardhan Jain H, Friedman A. Modeling prostate cancer response to continuous versus intermittent androgen ablation therapy. ACTA ACUST UNITED AC 2013. [DOI: 10.3934/dcdsb.2013.18.945] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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4
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Shariat SF, Semjonow A, Lilja H, Savage C, Vickers AJ, Bjartell A. Tumor markers in prostate cancer I: blood-based markers. Acta Oncol 2011; 50 Suppl 1:61-75. [PMID: 21604943 PMCID: PMC3571678 DOI: 10.3109/0284186x.2010.542174] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
UNLABELLED The introduction of total prostate specific antigen (total PSA) testing in blood has revolutionized the detection and management of men with prostate cancer (PCa). The objective of this review was to discuss the challenges of PCa biomarker research, definition of the type of PCa biomarkers, the statistical considerations for biomarker discovery and validation, and to review the literature regarding total PSA velocity and novel blood-based biomarkers. METHODS An English-language literature review of the Medline database (1990 to August 2010) of published data on blood-based biomarkers and PCa was undertaken. RESULTS The inherent biological variability of total PSA levels affects the interpretation of any single result. Men who will eventually develop PCa have increased total PSA levels years or decades before the cancer is diagnosed. Total PSA velocity improves predictiveness of total PSA only marginally, limiting its value for PCa screening and prognostication. The combination of PSA molecular forms and other biomarkers improve PCa detection substantially. Several novel blood-based biomarkers such as human glandular kallikrein 2 (hK2), urokinase plasminogen activator (uPA) and its receptor (uPAR), transforming growth factor-beta 1 (TGF-β1); interleukin-6 (IL-6) and its receptor (IL-6R) may help PCa diagnosis, staging, prognostication, and monitoring. Panels of biomarkers that capture the biologic potential of PCa are in the process of being validated for PCa prognostication. CONCLUSIONS PSA is a strong prognostic marker for long-term risk of clinically relevant cancer. However, there is a need for novel biomarkers that aid clinical decision making about biopsy and initial treatment. There is no doubt that progress will continue based on the integrated collaboration of researchers, clinicians and biomedical firms.
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Affiliation(s)
- Shahrokh F. Shariat
- Department of Urology and Medical Oncology, Weill Cornell Medical Center, New York, NY, USA
| | - Axel Semjonow
- Department of Urology, Prostate Center, University Hospital Muenster, Muenster, Germany
| | - Hans Lilja
- Department of Surgery (Urology Service), Clinical Laboratories, and Medicine (Genito-Urinary Oncology Service), Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Caroline Savage
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Andrew J. Vickers
- Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Anders Bjartell
- Department of Urology Malmö-Lund, Skåne University Hospital, Lund University, Sweden
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Skinner HG, Schwartz GG. The relation of serum parathyroid hormone and serum calcium to serum levels of prostate-specific antigen: a population-based study. Cancer Epidemiol Biomarkers Prev 2009; 18:2869-73. [PMID: 19861512 DOI: 10.1158/1055-9965.epi-09-0730] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Experimental and clinical data implicate calcium and parathyroid hormone (PTH) in the development of prostate cancer. However, epidemiologic data on the role of these variables in prostate health are sparse. We examined the relationship between serum levels of calcium, PTH, and prostate-specific antigen (PSA), an established marker of prostate growth, in a large, population-based study using multivariate linear regression. We studied 1,273 men in National Health and Nutrition Survey 2005 to 2006 who were >or=40 years of age and who were without clinical prostate cancer. Adjusted for age, race, body mass index, and serum levels of 25-hydroxyvitamin D, serum levels of PTH were significantly positively correlated with serum PSA (P = 0.01). Serum levels of PTH and calcium each were correlated significantly with free PSA (P = 0.05 and 0.008, respectively). The percentage of men who had elevated serum levels of PTH (PTH, >or=66 pg/mL) was significantly greater among African American men (19.2 versus 9.6%, P = 0.04). Compared with men whose PTH was at the lower end of the reference range, the predicted PSA for men with a PTH of 66 pg/mL was increased 43%. These findings support the hypothesis that serum calcium and serum PTH stimulate prostate growth in men without clinical prostate cancer and have implications for the use of PSA as a screening tool for prostate cancer.
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Affiliation(s)
- Halcyon G Skinner
- Department of Population Health Sciences, University of Wisconsin, Madison, Wisconsin, USA
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Bruun L, Savage C, Cronin AM, Hugosson J, Lilja H, Christensson A. Increase in percent free prostate-specific antigen in men with chronic kidney disease. Nephrol Dial Transplant 2008; 24:1238-41. [PMID: 19028756 DOI: 10.1093/ndt/gfn632] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Prostate-specific antigen (PSA) occurs in different molecular forms in serum: free PSA (fPSA) and complexed PSA (cPSA), the sum of which corresponds to total PSA (tPSA). In addition to tPSA, percent fPSA is widely used in the detection of prostate cancer. Free PSA, approximately 28 kDa, is eliminated by glomerular filtration. Previous data showed that men with end-stage renal dysfunction requiring chronic dialysis have increased percent fPSA. In this study, we evaluated whether moderate-to-severe chronic renal dysfunction, but with no need for dialysis, also importantly affects percent fPSA. METHODS The study group consisted of 101 men (median age 57 years, interquartile range 46-68) with chronic kidney disease and no diagnosis of prostate cancer. Their median glomerular filtration rate (GFR) was 23 mL/min/1.73 m(2) (interquartile range 16-33; range 8-83), determined by iohexol clearance. Controls included 5264 men (median age 57 years, interquartile range 54-62) attending a prostate cancer screening program with no diagnosis of prostate cancer during 8 years of follow-up. RESULTS With adjustment for age, median fPSA levels and percent fPSA were significantly higher (P < 0.001) in patients with renal dysfunction, 0.45 microg/L and 47.2%, respectively, compared to controls, 0.29 microg/L and 29.9%, respectively. Regression analysis in the study group showed a significant association between GFR and percent fPSA (P = 0.036). CONCLUSIONS The percent fPSA is importantly influenced by moderately impaired renal function in men with chronic kidney disease. For such men, use of the current clinical decision limits for percent fPSA could cause some men with prostate cancer to be misdiagnosed as having benign disease, and therefore fPSA should not be used to diagnose prostate cancer in these patients.
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Affiliation(s)
- Laila Bruun
- Department of Nephrology and Transplantation, University Hospital, UMAS, SE-205 02 Malmö, Sweden
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Moriya M, Ho YH, Grana A, Nguyen L, Alvarez A, Jamil R, Ackland ML, Michalczyk A, Hamer P, Ramos D, Kim S, Mercer JFB, Linder MC. Copper is taken up efficiently from albumin and alpha2-macroglobulin by cultured human cells by more than one mechanism. Am J Physiol Cell Physiol 2008; 295:C708-21. [PMID: 18579803 PMCID: PMC2544443 DOI: 10.1152/ajpcell.00029.2008] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2008] [Accepted: 06/19/2008] [Indexed: 11/22/2022]
Abstract
Ionic copper entering blood plasma binds tightly to albumin and the macroglobulin transcuprein. It then goes primarily to the liver and kidney except in lactation, where a large portion goes directly to the mammary gland. Little is known about how this copper is taken up from these plasma proteins. To examine this, the kinetics of uptake from purified human albumin and alpha(2)-macroglobulin, and the effects of inhibitors, were measured using human hepatic (HepG2) and mammary epithelial (PMC42) cell lines. At physiological concentrations (3-6 muM), both cell types took up copper from these proteins independently and at rates similar to each other and to those for Cu-dihistidine or Cu-nitrilotriacetate (NTA). Uptakes from alpha(2)-macroglobulin indicated a single saturable system in each cell type, but with different kinetics, and 65-80% inhibition by Ag(I) in HepG2 cells but not PMC42 cells. Uptake kinetics for Cu-albumin were more complex and also differed with cell type (as was the case for Cu-histidine and NTA), and there was little or no inhibition by Ag(I). High Fe(II) concentrations (100-500 microM) inhibited copper uptake from albumin by 20-30% in both cell types and that from alpha(2)-macroglobulin by 0-30%, and there was no inhibition of the latter by Mn(II) or Zn(II). We conclude that the proteins mainly responsible for the plasma-exchangeable copper pool deliver the metal to mammalian cells efficiently and by several different mechanisms. alpha(2)-Macroglobulin delivers it primarily to copper transporter 1 in hepatic cells but not mammary epithelial cells, and additional as-yet-unidentified copper transporters or systems for uptake from these proteins remain to be identified.
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Affiliation(s)
- Mizue Moriya
- Department of Chemistry and Biochemistry and Institute for Molecular Biology and Nutrition, California State University, Fullerton, California 92834-6866, USA
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Gregorakis AK, Stefanakis S, Malovrouvas D, Petraki K, Gourgiotis D, Scorilas A. Total and free PSA kinetics in patients without prostate cancer undergoing radical cystoprostatectomy. Prostate 2008; 68:759-65. [PMID: 18213630 DOI: 10.1002/pros.20733] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Radical cystoprostatectomy and radical prostatectomy are the two major operations where prostate is totally and radically removed. Radical cystoprostatectomy is usually performed in patients with invasive bladder cancer. The aim of the study was to examine Total PSA, Free PSA, and Free/Total Ratio elimination kinetics after radical cystoprostatectomy. METHODS Serum PSA, Free PSA, and Free/Total Ratio were determined preoperatively, at the time of cystoprostatectomy specimen removal and then at 3, 6, 12, 24, 48, 72, and 168 hr, from seven patients with muscle invasive bladder cancer, who underwent radical cystoprostatectomy. Free and Total PSA concentrations were measured with non-competitive immunological procedures. The elimination rates and half-lives of Total, Free PSA and Free/Total Ratio were studied using a nonlinear regression analysis. RESULTS Surgical manipulations caused about 1.5-fold increase of PSA, 5-fold increase in Free PSA and 3-fold increase in Free/Total Ratio. PSA and Free PSA followed a biphasic elimination pattern of a rapid exponential (a) phase with a half-life of 4.27 and 2.14 hr and a terminal, nonexponential (b) phase with a half-life of 63 and 173.2 hr, respectively. Free/Total PSA Ratio followed, also, a biphasic kinetic pattern of a rapid exponential decline with a half-life of 3.34 and a terminal non-exponential increase with a doubling time of 43 hr. CONCLUSIONS Comparing PSA kinetics after radical cystoprostatectomy with those of radical prostatectomy, it appears that PSA follows the same elimination pattern in both models. In contrast, Free PSA and Free/Total Ratio elimination kinetics' patterns differ between the two surgical models.
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Ahn JO, Ku JH. Relationship between serum prostate-specific antigen levels and body mass index in healthy younger men. Urology 2006; 68:570-4. [PMID: 16979743 DOI: 10.1016/j.urology.2006.03.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Revised: 02/02/2006] [Accepted: 03/09/2006] [Indexed: 11/21/2022]
Abstract
OBJECTIVES To understand further the physiologic characteristics of serum prostate-specific antigen (PSA) concentrations in healthy younger men. METHODS A total of 2032 men, 20 to 39 years old, who visited our hospital for a routine health checkup were entered into the study. Pearson correlation coefficients were determined to evaluate the association between serum PSA and clinical parameters. Because of the log-normal distribution, the serum PSA levels were log-transformed for analysis. RESULTS Although the relationships were weak, significant negative correlations were noted between serum PSA and body weight (r = -0.107, P <0.001), body mass index (BMI; r = -0.131, P <0.001), aspartate aminotransferase (AST; r = -0.076, P = 0.001), alanine aminotransferase (ALT; r = -0.079, P = 0.001), gamma-glutamyltransferase (r = -0.046, P = 0.046), and creatinine clearance (r = -0.113, P <0.001). A positive correlation was found between serum PSA and creatinine (r = 0.053, P = 0.024). Age did not correlate with serum PSA level. The influence of clinical parameters on serum PSA was explored using multiple linear regression analysis. Using the stepwise method, all other explanatory variables, except BMI, AST, and creatinine were eliminated (log10[PSA] = -0.124[BMI] + 0.063[creatinine] - 0.053[AST] + 0.097; r = 0.152, P <0.001). CONCLUSIONS BMI, creatinine, and AST may influence the serum PSA level in this population. However, because it was not clear that this group should be considered at high risk of prostate cancer in the future, additional longitudinal research is needed.
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Affiliation(s)
- Jae Ouk Ahn
- Department of Medical Informatics, Soonchunhyang University School of Medicine, Seoul, Korea
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Bruun L, Becker C, Hugosson J, Lilja H, Christensson A. Assessment of intra-individual variation in prostate-specific antigen levels in a biennial randomized prostate cancer screening program in Sweden. Prostate 2005; 65:216-21. [PMID: 15948137 PMCID: PMC1951509 DOI: 10.1002/pros.20286] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND The degree of variability in prostate-specific antigen (PSA) measurements is important for interpreting test results in screening programs, and particularly for interpreting the significance of changes between repeated tests. This study aimed to determine the long-term intra-individual variation for PSA in healthy men. METHODS A randomly selected cohort of men in a biennial prostate cancer screening program (ERSPC) conducted in Sweden from 1995-1996 to 2001-2002. We studied men who had total PSA (tPSA) levels < 2.0 ng/ml in 2001-2002. This included 791 men with tPSA < or = 0.61 ng/ml (group A), 1,542 men with tPSA < or = 0.99 ng/ml (group B), and 1,029 men with tPSA 1.00-1.99 ng/ml (group C). The intra-individual variability of free PSA (fPSA) and tPSA was assessed by calculating coefficients of variation (CV) for each individual's PSA measurements from the first and second round of screening (1995-1996 and 1997-1998). RESULTS Intra-individual CV (geometric means) for tPSA were 13.7%, 12.7%, and 11.5% in groups A, B, and C, respectively. Corresponding CVs for fPSA were significantly lower, ranging from 12.1% to 10.4%. The estimated biological variation of tPSA and fPSA in groups A to C were 12.5%, 11.4%, 10.0% and 9.7%, 7.8%, 7.5%, respectively. CONCLUSIONS In healthy men with PSA levels less than 2 ng/ml, the natural long-term variability for tPSA was less than 14%, and with 95% probability, a change in tPSA greater than 30% indicates a change beyond normal random variation.
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Affiliation(s)
- Laila Bruun
- Department of Nephrology and Transplantation, Lund University, University Hospital (UMAS), Malmö, Sweden.
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Gregorakis AK, Malovrouvas D, Stefanakis S, Petraki K, Scorilas A. Free/Total PSA (F/T ratio) kinetics in patients with clinically localized prostate cancer undergoing radical prostatectomy. Clin Chim Acta 2005; 357:196-201. [PMID: 15936010 DOI: 10.1016/j.cccn.2005.03.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Accepted: 03/09/2005] [Indexed: 11/24/2022]
Abstract
BACKGROUND In this paper we study the Free/Total PSA kinetics in patients with clinically localized prostate cancer undergoing radical prostatectomy. METHODS Serum PSA, Free PSA and Free/Total Ratio were determined preoperatively, at the time of prostate removal (0 time) and then at 3, 6, 12, 24, 48, 72 and 168 h, from 9 patients with clinically localized prostate cancer who underwent radical retropubic prostatectomy. The elimination rates and half-lives of Total, Free PSA and F/T Ratio were studied applying one and two compartment models for pharmacokinetic analysis. RESULTS Surgical manipulations of the prostate caused a mean 2.16-fold increase of PSA, 12-fold increase of free PSA and 4.2-fold increase of F/T PSA ratio. Removal of the prostate caused a rapid biphasic, biexponential elimination of Free PSA with a mean half-life of 0.8 h for the alpha (a) phase and 32.6 h for the beta (b) phase. PSA was eliminated following a rapid exponential (a) phase with a half-life of 1.15 h and a non-exponential (b) phase with a half-life of 71.96 h. Free/Total PSA followed a biphasic kinetic, with an initial exponential elimination phase and a mean half-life of 2.6 h and a second non-exponential increase phase with a doubling time of 130.8 h. Free/Total PSA reached its nadir very soon, at the first postoperative 24 h. CONCLUSIONS Free/Total PSA kinetic after radical prostatectomy reflects the differences of Free and Total PSA elimination kinetics. Free/Total Ratio follows a biphasic kinetic, with an initial rapid exponential elimination phase, which is affected mainly by the rapid exponential (a) phase of Free PSA elimination and a second slow increase, which is affected mainly by the terminal non-exponential (b) phase of PSA elimination.
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Sävblom C, Malm J, Giwercman A, Nilsson JA, Berglund G, Lilja H. Blood levels of free-PSA but not complex-PSA significantly correlates to prostate release of PSA in semen in young men, while blood levels of complex-PSA, but not free-PSA increase with age. Prostate 2005; 65:66-72. [PMID: 15880475 DOI: 10.1002/pros.20254] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The proportion of free- and complex-prostate specific antigen (PSA) in serum is used for differentiating between benign and malignant prostate disease. To further understand the physiological relationship between PSA in seminal plasma and blood, we have analyzed free-PSA (fPSA) and complex-PSA (cPSA) in blood and PSA in seminal plasma in young healthy men. We also compared age-related changes of PSA-forms in blood from young versus older men. METHODS Total-PSA (tPSA), fPSA, and cPSA were measured in (i) blood and semen from 289 male conscripts (mean age 18.1 years) and in (ii) blood from a representative population of 1,389 men (mean age 46.5 years) without diagnosis of prostate cancer (PCa) during long-term follow-up. RESULTS fPSA in serum (r = 0.40, P < 0.0001) but not cPSA (r = 0.09, P = 0.11), correlates to PSA in seminal fluid. fPSA levels in blood in young (geometric mean: 0.20 ng/ml) versus middle-aged men (geometric mean: 0.18 ng/ml) was not different (P = 0.06), whereas cPSA in middle-aged men (geometric mean: 0.38 ng/ml) was higher (P < 0.0001) than in young men (geometric mean: 0.28 ng/ml). CONCLUSIONS fPSA in blood, but not cPSA, is associated to PSA in semen ( approximately 17% co-variation). In blood cPSA, but not fPSA, increase with age in healthy men, which may reflect an increasing incidence of prostate disease.
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Affiliation(s)
- Charlotta Sävblom
- Department of Laboratory Medicine, Division of Clinical Chemistry, Lund University, Malmö University Hospital, Malmö, Sweden.
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Obiezu CV, Shan SJC, Soosaipillai A, Luo LY, Grass L, Sotiropoulou G, Petraki CD, Papanastasiou PA, Levesque MA, Diamandis EP. Human kallikrein 4: quantitative study in tissues and evidence for its secretion into biological fluids. Clin Chem 2005; 51:1432-42. [PMID: 15961548 DOI: 10.1373/clinchem.2005.049692] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Human kallikrein 4 (hK4) is a proteolytic enzyme belonging to the tissue kallikrein family of serine proteases. Previous tissue expression studies have demonstrated highest KLK4 mRNA expression in prostatic tissue, but there has been only limited evidence for the presence of hK4 protein in prostate and other tissues and in corresponding biological secretions. METHODS To investigate the concentrations of hK4 in tissues and biological fluids, we developed a new hK4-specific sandwich-type immunoassay using a monoclonal antibody as the capture reagent. RESULTS The assay has a detection limit of 0.02 microg/L and <0.1% cross-reactivity toward any of the other 14 human kallikreins. Twelve of 40 tissue extracts prepared from various human tissues contained detectable hK4 concentrations (0.68-7143 ng/g of total protein), with healthy prostate tissue containing the highest amount of hK4. Examination of 16 malignant and 18 benign prostate tissues revealed no significant differences in hK4 protein content, and the tissues contained a wide range of values (benign, <0.02 to 801 ng/g; malignant, <0.02 to 824 ng/g). Among the biological fluids tested, seminal plasma and urine contained widely varying amounts of hK4; concentrations in 54 urine samples were <0.02 to 2.6 microg/L, whereas concentrations in 58 seminal plasma samples were 0.2-202 microg/L. Affinity purification of hK4 from seminal plasma and subsequent mass spectrometry demonstrated the secreted nature of hK4 in seminal plasma. CONCLUSIONS hK4 is found primarily in prostate tissue and is secreted in seminal plasma. Its value as a novel prostatic biomarker needs to be defined further.
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Affiliation(s)
- Christina V Obiezu
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada
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Linder S, Havelka AM, Ueno T, Shoshan MC. Determining tumor apoptosis and necrosis in patient serum using cytokeratin 18 as a biomarker. Cancer Lett 2004; 214:1-9. [PMID: 15331168 DOI: 10.1016/j.canlet.2004.06.032] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2004] [Accepted: 06/24/2004] [Indexed: 12/15/2022]
Abstract
Intracellular macromolecules are released from dying tumor cells and may subsequently be detected in patient blood. In this review, we will discuss the use of cytokeratin-18 as a serum biomarker for monitoring therapy-induced cell death. Cytokeratins are abundant intracellular proteins expressed by most types of carcinoma, but not by treatment-sensitive cells from bone marrow and other tissues. Release of cytokeratins into blood is therefore expected to show some specificity for tumor cell death. Cytokeratin-18 (CK18) is cleaved by caspases specifically during apoptosis, and the molecular form of this protein (caspase-cleaved vs. non-cleaved) released from dying tumor cells is therefore diagnostic as to the type of cell death (apoptosis vs. necrosis). Analyses of different CK18 forms in patient sera have suggested that tumor apoptosis may not necessarily be the dominating death mode in many tumors in vivo. Measurements of increased levels of CK18 in serum during therapy of prostate and breast cancer patients have been encouraging with regard to the possible future use of CK18 as a biomarker for monitoring therapy efficiency.
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Affiliation(s)
- Stig Linder
- Department of Oncology and Pathology, Cancer Center Karolinska, Karolinska Institute and Hospital, S-171 76 Stockholm, Sweden.
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Gläser C, Schulz S, Handschug K, Huse K, Birkenmeier G. Genetic and functional characteristics of the human in vivo LRP1/A2MR receptor suggested as a risk marker for Alzheimer’s disease and other complex (degenerative) diseases. Neurosci Res 2004; 50:85-101. [PMID: 15288502 DOI: 10.1016/j.neures.2004.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Accepted: 06/01/2004] [Indexed: 11/29/2022]
Abstract
LDL receptor-related protein/alpha2-macroglobulin receptor (LRP1/A2MR) a multiligand receptor is considered as not only being a possible risk factor of neurodegenerative diseases like Alzheimer's disease but also as determining the progression of other complex diseases like atherosclerosis and cancer. Although a large number of in vitro studies have highlighted its functional importance, as yet not enough is known about the clinical importance of the genetic background of LRP1 in human diseases. The aim of this ex vivo/in vivo study of 448 subjects was to present data on genetic LRP1 variants of healthy European Caucasians from Central Germany. Genotype-dependent LRP1 expression was analyzed in a representative subgroup (gene expression: n = 127, protein expression: n = 44). These data were evaluated in comparison to other published clinical LRP1 studies. For 15 functionally interesting genetic variants the genotype and allele distributions of the German Caucasians were presented in relation to their in vivo LRP1 gene and protein expression. A direct influence of the LRP1 promoter polymorphism c.1-25C>G on the human in vivo LRP1 expression level was demonstrated. In an analysis of 48 further studies genomic and functional results were evaluated. The analysis especially on Alzheimers's disease partly highlighted contradictory results, but suggested that ethnic as well as genomic characteristics determine LRP1 expression and must be considered in clinical investigations on human LRP1.
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Affiliation(s)
- Christiane Gläser
- Institute of Human Genetics and Medical Biology, University of Halle, Magdeburger Str. 2, D-06097 Halle, Germany.
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Luboldt HJ, Peck KD, Oberpenning F, Schmid HP, Semjonow A. Bicycle riding has no important impact on total and free prostate-specific antigen serum levels in older men. Urology 2003; 61:1177-80. [PMID: 12809893 DOI: 10.1016/s0090-4295(03)00007-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To investigate whether bicycle riding significantly alters total prostate-specific antigen (tPSA), free PSA (fPSA), and percent free PSA (%fPSA) serum concentrations in potential candidates for prostate cancer screening. METHODS Thirty-three men, ranging in age from 50 to 74 years (mean 61 +/- 8), rode a 13-mile bicycle course. Blood samples for PSA analysis were drawn immediately before and 1 hour after cycling for 90 minutes. The precycling and postcycling tPSA, fPSA, and %fPSA values were compared using the Wilcoxon matched-pairs test, with P = 0.01 set as the significance level. RESULTS Changes between precycling and postcycling values for tPSA (P = 0.517), fPSA (P = 0.048), and %fPSA (P = 0.166) were not statistically significant. CONCLUSIONS Physical activity combined with perineal pressure as induced by a 13-mile bicycle tour has no diagnostic impact on PSA values.
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Hsieh MC, Cooperman BS. Inhibition of prostate-specific antigen (PSA) by alpha(1)-antichymotrypsin: salt-dependent activation mediated by a conformational change. Biochemistry 2002; 41:2990-7. [PMID: 11863437 DOI: 10.1021/bi0117450] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Prostate-specific antigen (PSA) and its SDS-stable complex with the serine proteinase inhibitor (serpin) alpha(1)-antichymotrypsin (ACT), which is the dominant form of PSA in serum, are in widespread use as markers for the diagnosis of prostate cancer, and there is increasing evidence for the involvement of PSA proteinase activity itself in the development of prostate and other cancers. However, both the formation and degradation of the PSA-ACT complex, denoted PSA*ACT* to indicate substantial changes in the structure of both proteins on complex formation, have been incompletely studied. Here we determine rate and equilibrium constants for the steps involved in PSA*ACT* formation and demonstrate that (a) the effects of added NaCl, polyamines, and Zn(2+) on this process parallel their effects on PSA catalytic activity [Hsieh, M.-C., and Cooperman, B. S. (2000) Biochim. Biophys. Acta 1481, 75-87], (b) the effect of added NaCl in dramatically increasing the rate of ACT inhibition of PSA correlates with salt-induced changes in PSA conformation, and (c) the PSA*ACT* complex is subject to proteolysis by human neutrophil elastase. Possible clinical implications of these findings are considered.
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Affiliation(s)
- Ming-Ching Hsieh
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, USA
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Lotan Y, Roehrborn CG. Clearance rates of total prostate specific antigen (PSA) after radical prostatectomy in African-Americans and Caucasians. Prostate Cancer Prostatic Dis 2002; 5:111-4. [PMID: 12496998 DOI: 10.1038/sj.pcan.4500567] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2001] [Revised: 11/25/2001] [Accepted: 11/29/2001] [Indexed: 11/08/2022]
Abstract
Racial differences in serum prostate specific antigen (PSA) values in men with and without prostate cancer have been observed but have yet to be explained. We aimed to determine if ethnic variations in the rate of metabolism of PSA could explain the different levels of PSA found in African-American and Caucasian men. In a prospective fashion, patients diagnosed with biopsy-proven clinically localized adenocarcinoma of the prostate and scheduled for radical prostatectomy were selected for the study. Eleven patients (six Caucasian, five African-American) were enrolled in the study. All patients demonstrated normal liver and renal function. Sera for total PSA were obtained at the following time intervals: preoperative (within 3 months of operation), time 0 (at time of prostate removal), 1, 4, 8, 24, 48, 72, 168 and 336 h after removal of the prostate. A log-linear regression model was then used to determine the metabolic clearance rate and half-life of serum total PSA. There were no statistically significant differences between Caucasian and African-American patients with regard to age, PSA prior to surgery, prostate weight, Gleason sum and PSA half-life. The metabolic clearance of total PSA followed first order kinetics. When comparing serum PSA levels expressed as a fraction of the baseline PSA, Caucasian and African-American patients demonstrated similar rates of metabolism. This study found similar rates of elimination of serum total PSA between African-Americans and Caucasians. These findings suggest that the rate of metabolism of PSA is similar for these groups. Further studies are needed to explain racial differences of serum PSA in patients with and without prostate cancer.
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Affiliation(s)
- Y Lotan
- Department of Urology, The University of Texas Southwestern Medical Center at Dallas, Texas 75390-9110, USA
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Becker C, Noldus J, Diamandis E, Lilja H. The role of molecular forms of prostate-specific antigen (PSA or hK3) and of human glandular kallikrein 2 (hK2) in the diagnosis and monitoring of prostate cancer and in extra-prostatic disease. Crit Rev Clin Lab Sci 2001; 38:357-99. [PMID: 11720279 DOI: 10.1080/20014091084236] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Prostate-specific antigen (PSA or hK3) is a glandular kallikrein with abundant expression in the prostate that is widely used to detect and monitor prostate cancer (PCa), although the serum level is frequently elevated also in benign and inflammatory prostatic diseases. PSA testing is useful for early detection of localized PCa and for the detection of disease recurrence after treatment. However, PSA has failed to accurately estimate cancer volume and preoperative staging. There is no PSA level in serum that definitively distinguishes men with benign conditions from those with prostate cancer, although PCa is rare in men with PSA levels in serum < 2.0 ng/ml. This prompted searches for enhancing parameters to combine with PSA testing, such as PSA density, PSA velocity, and age-specific reference ranges. Due to the protease structure, PSA occurs in different molecular forms in serum and their concentrations vary according to the type of prostatic disease. Human glandular kallikrein 2 (hK2) is very similar to PSA, but expressed at higher levels in prostate adenocarcinoma than in normal prostate epithelium. Blood testing for hK2 combined with different PSA forms improves discrimination of men with benign prostatic disease from those with prostate cancer. Many data have also been reported on the extra-prostatic expression of both PSA and hK2, and it is now believed that they may both have functions in tissues outside the prostate.
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Affiliation(s)
- C Becker
- Dept. of Clinical Chemistry, Lund University, Malmö University Hospital, Malmö, Sweden.
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Affiliation(s)
- U Stenman
- Department of Clinical Chemistry, Helsinki University Central Hospital, Helsinki, Finland
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22
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Zhang WM, Finne P, Leinonen J, Salo J, Stenman UH. Determination of prostate-specific antigen complexed to alpha(2)-macroglobulin in serum increases the specificity of free to total PSA for prostate cancer. Urology 2000; 56:267-72. [PMID: 10925092 DOI: 10.1016/s0090-4295(00)00609-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES To determine whether prostate-specific antigen (PSA) complexed to alpha(2)-macroglobulin (A2M) increases the specificity of free PSA (fPSA) and total PSA (tPSA) for the diagnosis of prostate cancer (PCa). METHODS In a series of 73 patients with PCa and 58 with benign prostatic hyperplasia (BPH), fPSA, tPSA, and PSA complexed with A2M (PSA-A2M) in serum were determined by specific immunoassays. The assay for PSA-A2M was based on the immunoadsorption of immunoreactive PSA in serum and the measurement of the PSA immunoreactivity released by denaturation of PSA-A2M at pH 11.4. RESULTS The median proportion of PSA-A2M [ %PSA-A2M=PSA-A2M/(tPSA+PSA-A2M)] and that of fPSA ( %fPSA=fPSA/tPSA) were significantly lower in patients with PCa (8.2% and 12.4%, respectively) than in patients with BPH (11.6% and 22.5%, P = 0.0014 and P <0.0001, respectively). The median sum of %PSA-A2M and %fPSA was 22.4% in PCa and 38.2% in BPH (P <0.0001). When the sum of %PSA-A2M and %fPSA was used as a diagnostic test for PCa, 57% of patients with "falsely" elevated PSA concentrations (4 to 10 ng/mL) caused by BPH could be correctly identified without missing patients with PCa compared with 18% of the patients with BPH but not PCa using %fPSA alone. CONCLUSIONS Measurement of the sum of %PSA-A2M and %fPSA in serum significantly improves the cancer specificity of the PSA test compared with the use of tPSA and %fPSA.
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Affiliation(s)
- W M Zhang
- Department of Clinical Chemistry, Helsinki University Central Hospital, Helsinki, Finland
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