The effect of prolonged intense physical exercise of special forces volunteers on their plasma protein denaturation profile examined by differential scanning calorimetry.

The human blood plasma proteome profile has been an area of intensive investigation and differential scanning calorimetry (DSC) has come forward as a novel tool in analyzing plasma heat capacity changes to monitor various physiological responses in health and disease. This study used DSC to assess potential alterations in the plasma heat capacity profile of albumin and globulins during extremely demanding physical exercise. We monitored the changes in denaturation profiles of those plasma proteins for five consecutive days of an extraordinary exercise training schedule in 14 young male Special Forces volunteers, as well as after a 30-day recovery period. The major effect of the prolonged intense exercise was the continuous upward shift of the albumin peak by 2°-3 °C on the initial days of exercise, with a tendency to plateau circa the 5th day of exercise. In addition, some redistribution of the denaturational enthalpy was observed upon exercise, where the globulins peak increased relative to the albumin peak. Noteworthy, the alterations in the plasma proteome denaturational profiles were not persistent, as virtually full recovery of the initial status was observed after 30 days of recovery. Our findings indicate that 5 days of exhaustive physical exercise of highly trained individuals enhanced the thermal stability of plasma albumin shifting its denaturational transition to higher temperatures. We surmise that these effects may be a result of increased blood oxygenation during the prolonged intense exercise and, consequently, of albumin oxidation as part of the overall adaptation mechanisms of the body to extreme physical and/or oxidative stress.

Detection of the circulating tumor cells in cancer patients.

As the presence of tumor cells circulating in the blood is associated with systemic disease and shortened survival, the establishment of a method to detect circulating tumor cells (CTCs) is of critical importance for a more concise staging and follow-up of cancer patients. Recently, the most robust strategies for the determination of CTCs are the PCR-based methods and the CellSearch® system that exploits the immunofluorescent characterization and isolation of cancer cells. Herein, we analyzed the experimental strategies used for determining CTCs with respect to accuracy, sensitivity and reproducibility in cancers of the breast, colon, prostate and melanoma.

Detection of circulating tumor cells in prostate cancer patients: methodological pitfalls and clinical relevance.

Disseminated malignancy is the major cause of prostate cancer-related mortality. Circulating tumor cells (CTCs) are essential for the establishment of metastasis. Various contemporary and molecular methods using prostate-specific biomarkers have been applied to detect extraprostatic disease that is undetectable by conventional imaging techniques, assessing the risk for disease recurrence after therapy of curative intent. However, the clinical relevance of CTC detection is still controversial. We review current literature regarding molecular methods used for the detection of CTCs in the peripheral blood and bone marrow biopsies of patients with prostate cancer, and we discuss the methodological pitfalls that influence the clinical significance of molecular staging.

The glutamatergic system expression in human PC-3 and LNCaP prostate cancer cells.

BACKGROUND: The glutamatergic system (Glu system) comprises the Glu receptors (GluRs), the Glu transporters (GluTs) and glutamine synthetase (GS). MATERIALS AND METHODS: Using PCR-based detection and Western blot analysis, the expression of Glu system components was assessed in human androgen-independent PC-3 and androgen-dependent LNCaP prostate cancer cells. RESULTS: iGluRs, such as NR1, NR2A, NR2C, NR2D and NR3B; mGLuRs such as mGluR1, mGluR2, mGluR3, mGluR4 and mGluR5; GluTs such as EAAT1, EAAT2, EAAT3 and EAATS; and GS mRNA were steadily expressed in both cell lines. In addition, NR3A, mGluR6, mGluR8 and EAAT4 mRNA were differentially expressed in PC-3 and LNCaP cells, mGluR7 and EAAT4 mRNA expression was induced and mGluR8 was silenced by dihydrotestosterone (DHT) treatment in LNCaP cells. GS, EAAT1 and mGLuR5 were also detected at the protein level in both PC-3 and LNCAP cells. CONCLUSION: These data suggest that the Glu system could be an important regulator of prostate cancer cell biology.

IL-6 and PPARgamma signalling in human PC-3 prostate cancer cells.

BACKGROUND: Peroxisome proliferator-activated receptor gamma (PPARgamma) ligands and interleukin (IL)-6 are key factors for controlling prostate cancer cell proliferation and survival. MATERIALS AND METHODS: Herein we used the natural PPARgamma ligand, 15deoxy Delta12-14 PGJ(2) (15dPGJ(2)), and IL-6 to define their interactions on proliferation and signal transduction in PC-3 cells. Cytotoxic and trypan blue exclusion assays, Western blot analysis of mitogen-activated protein kinases (MAPK) and Janus kinase/Signal transducer and activator of transcription (JAK/Stat) and real-time polymerase chain reaction (PCR) were methods employed as investigation tools. RESULTS: 15dPGJ(2) reduced PC-3 cell proliferation, while IL-6 increased it. IL-6 induced PPARgamma expression but did not affect the PPARgamma ligand-mediated effects on the proliferation of PC-3 cells. However, 15dPGJ(2) inhibited the IL-6-mediated increase of PC-3 cell proliferation. 15dPGJ(2) activated Erk1/2 phosphorylation without affecting Akt phosphorylation and reduced phosphorylated and unphosphorylated Stat3 in PC-3 cells. IL-6 suppressed endogenous activation of Stat3 without affecting Erk1/2 and Akt phosphorylation and suppressed the 15dPGJ(2)-mediated activation of Erk1/2 phosphorylation in PC-3 cells. CONCLUSION: The interplay between PPARgamma ligands and IL-6 signalling could be important in controlling the growth of androgen independent prostate cancer cells as exemplified by PC-3 cells.

Bone-related growth factors and zoledronic acid regulate the PTHrP/PTH.1 receptor bioregulation systems in MG-63 human osteosarcoma cells.

Bisphosphonates are known to inhibit osteoclast-mediated bone resorption and osteoblast differentiation and are currently used in the treatment of Paget's disease, osteoporosis, metastatic and osteolytic bone disease and hypercalcaemia of malignancy. The parathyroid hormone-related peptide (PTHrP) and type 1 PTH/PTHrP receptor (PTH.1R) bioregulation systems mediate a wide range of local paracrine/autocrine and intracrine functions in various tissues and modify the actions of pharmaceutical agents on target tissues, both in vivo and in vitro. In addition, bone microenvironment-related growth factors, such as insulin-like growth factor 1 (IGF-1), transforming growth factor beta 1 (TGF beta 1), basic fibroblast growth factor (bFGF) and interleukin 6 (IL-6), can modify the actions of various pharmaceutical agents, including cytotoxic drugs in malignant cell lines. Whether IGF-1, TGF beta 1, bFGF, IL-6 and zoledronic acid affect the expressions of PTHrP and PTH.1R in MG-63 osteoblast-like osteosarcoma cells was investigated in this study. Relative quantitative-PCR (expression at mRNA level) and immunofluorescence analysis (localization of the expression at protein level) were employed to assess PTHrP and PTH.IR expressions. Our data showed that primarily IGF-1, TGF beta 1 and IL-6 (up to 25 ng/ml for 48 h) increased PTHrP mRNA expression and modified its perinuclear localization, while zoledronic acid (up to 100 microM for 48 h) inhibited cell proliferation and suppressed PTHrP expression in the MG-63 osteosarcoma cells. These growth factors were incapable of reversing the zoledronic acid decrease of the expression of PTHrP in the MG-63 cells, suggesting that zoledronic acid and the growth factors affect PTHrP expression via an independent intracellular signal transduction pathway in these cells. However, no appreciable modulation of the PTH.1R expression by IGF-1, TGF beta 1, bFGF, IL-6 or zoledronic acid was detected in MG-63 cells. Therefore, we conclude that PTHrP expression possibly mediates the action of bone microenvironment-related growth factors and of zoledronic acid in MG-63 cells.

Serum testosterone: A potentially adjunct screening test for the assessment of the risk of prostate cancer among men with modestly elevated PSA values (> or =3.0 and <10.0 ng/ml).

Whether serum testosterone (T) can become an adjunct test able to validate the PSA-weighted risk of prostate cancer (PR.CA) in the "grey" diagnostic area (PSA =3.0 to <10.0 ng/ml) was investigated. Seven hundred and eighteen men participated in a prostate screening program using the cutoff PSA value of > or =3.0 ng/ml. PR.CA was found in 26% (22/85) of men with PSA testing within the "grey" diagnostic area and 58% (7/12) with PSA testing > or =10 ng/ml, among the 97 men who agreed to undergo transrectal ultrasound-guided biopsy (TRUS-guided biopsy). The PSA values showed a statistically significant positive association with diagnosis of PR.CA, whereas T and the T/PSA ratio were inversely and significantly related to the disease. In addition, out of 718 subjects, 45 (2.6%) were found to have a T value <2.6 ng/ml and another 78 (10.8%) had "low normal T value" (2.6> or = T <3.0 ng/ml). Of the hypogonadal men, 16 received testosterone enanthate (depot T; 250 mg/ml oily injection, intramuscularly: i.m.; TRT) and three had PSA levels >3.0 ng/mlpost-TRT; one was eventually diagnosed with PR.CA. An empirically-determined cut-off of the T/PSA ratio [>95 ("negative") or <0.95 ("positive")] was found to be optimal with regard to both sensitivity/specificity. This test was "positive" among 95.5% of the PR.CA patients, whereas 81% of biopsies confirmed that non-PR.CA had a "negative" TIPSA ratio, indicating that this ratio can become an adjunct screening test in assessing the risk of PR. CA; in particular, the odds of PR. CA increasing sharply (1/0.08= 12.5 times) with a decrease of the TIPSA ratio by one standard deviation. We conclude that the measurement of the serum T value can become an adjunct test validating further the PSA-weighted risk of PR. CA within the "grey" diagnostic area.

Molecular staging using qualitative RT-PCR analysis detecting thyreoglobulin mRNA in the peripheral blood of patients with differentiated thyroid cancer after therapy.

BACKGROUND: The prognostic significance of molecular staging using thyroglobulin (Tg)-based RT-PCR analysis in the peripheral blood of patients with differentiated thyroid cancer (DTC) was investigated. Herein, the specificity of molecular staging in DTC patients after thyroidectomy and 131I ablation therapy was analysed, using different specific cDNA primers in qualitative nested and classical RT-PCR protocols. PATIENTS AND METHODS: Ninty-five patients receiving TSH suppressive therapy were included, of whom 51 were disease-free and 44 presented residual/recurrent or metastatic disease as evidenced by biochemical and/or 131I whole-body scan. RESULTS: Our analysis detected RT-PCR products suggestive of the presence of Tg mRNA in all the blood samples tested, including healthy controls. A splice variant (350 bp) of Tg transcript (missing exon 3) was detected by nested RT-PCR in 34% of blood samples, however, without correlation to disease status. CONCLUSION: Qualitative Tg-based molecular staging in the peripheral blood of patients with DTC shows poor specificity in assessing DTC disease status.

Molecular staging by RT-pCR analysis for PSA and PSMA in peripheral blood and bone marrow samples is an independent predictor of time to biochemical failure following radical prostatectomy for clinically localized prostate cancer.

Radical prostatectomy should ideally be curative for all patients with clinically localized prostate cancer (PrCa), yet a sizeable proportion of them eventually relapse. We examined in this setting the feasibility of pre-operative risk stratification for early post-operative relapse using reverse transcriptase polymerase chain reaction (RT-PCR) for prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) transcripts in preoperative bone marrow (BM) biopsies and peripheral blood (PBL) samples. Nested RT-PCR for PSA and PSMA transcripts were performed in RNA from BM biopsies and PBL samples prospectively obtained from 111 men newly diagnosed, by trans-rectal ultrasound (TRUS)-guided biopsy, with clinically localized PrCa and scheduled to undergo radical prostatectomy, according to their respective doctors' recommendation. Molecular analysis for each sample (PBL or BM) was considered positive only if both PSA and PSMA transcripts were detectable. Serial serum PSA level measurements served for biochemical follow-up and detection of biochemical failure (PSA >0.2 ng/ml). PBL and BM RT-PCR molecular staging delineated three groups of patients (a) PBL-BM- (72 patients, 65%), (b) PBL+BM+ (29 patients, 26%), and (c) PBL+BM- (10 patients, 9%). These three groups corresponded to low, high, and intermediate risk for early post-prostatectomy recurrence (median time to biochemical failure of >38, 8, and >28 months, respectively). Multivariate analysis confirmed that molecular staging status was independent predictor of disease-free survival, after adjusting for PSA levels and Gleason score. In clinically localized PrCa, combined PSA/PSMA RT-PCR in PBL and BM is an independent predictor of time to biochemical failure following radical prostatectomy.

Urokinase-type plasminogen activator and insulin-like growth factor-binding protein 3 mRNA expression in endometriotic lesions and eutopic endometrium: implications for the pathophysiology of endometriosis.

The peritoneal fluid of women with endometriosis contains an increased insulin-like growth factor 1 (IGF-1) bioavailability, which is produced by limited hydrolysis of urokinase-type plasminogen activator (uPA) on IGF-binding protein 3 (IGFBP-3). Recently, IGF-1 was shown to inhibit apoptosis of endometrial-like cells in vitro, suggesting that a microenvironment of increased IGF-1 bioavailability can optimize the survival of endometrial cells grown ectopically. Here the expression of mRNA of IGFBP-3 and uPA in tissue biopsies from eutopic endometrium and endometriotic lesions obtained at laparoscopy from women with endometriosis have been analyzed, and it is documented that both IGFBP-3 and uPA mRNA expression are increased from 3- to 10-fold in endometriotic lesions versus eutopic endometrium. Consequently, the necessary components (uPA and IGFBP-3 expression) of endocrine/autocrine/paracrine enhancement of local IGF bioavailability mediated by uPA hydrolysis of the IGFBP-3 were present in endometriotic lesions. These data possibly explain the origin of the increased content of uPA activity, IGF-1 bioavailability, and NH(2)-truncated forms of IGFBP-3 in the peritoneal fluid of women with endometriosis.

Characterization of the glutametergic system in MG-63 osteoblast-like osteosarcoma cells.

BACKGROUND: The glutamate system is a fairly complex bioregulation pathway, consisting of several ionotropic Glu receptors (iGlu.Rs), the metabotropic Glu receptors (mGlu.Rs), Glu transporters (EAATs) and glutamine synthetase (GS), which metabolizes glutamate to glutamine. MATERIALS AND METHODS: We characterized the MG-63 human osteoblast-like osteosarcoma cells with regards to mRNA expression of the (a) NMDA.R group of iGlu.Rs, (b) mGlu.Rs, (c) EAAT1 transporter, and (d) GS, using specific primers for their detection by RT-PCR. RESULTS: Our data confirm the mRNA expression of the NR1, NR2A, NR2B and NR2D subunits of NMDA.R and of GS mRNA in MG-63 cells. In addition, we documented, for the first time, the mRNA expression of the NR3A, EAAT1, mGlu.R1, mGlu.R2, mGlu.R3, mGluR.4, mGlu.R5 and mGlu.R8 mRNA. However, we did not detect the mRNA expression of NR2C, NR3B, mGlu.R6 and mGlu.R7 mRNA. CONCLUSION: Our data suggest that MG-63 cells can be used as a model for studying the possible role of Glu beyond CNS.

Male breast adenocarcinoma in a prostate cancer patient following prolonged anti-androgen monotherapy.

We report the case of an 82-year-old male patient with a > 8-year history of prostate cancer (PrCa), who developed breast adenocarcinoma (BrCa) (Ki-67+ and negative for ER, PR, PSA and HER2/neu) after prolonged (approximately 7-year) anti-androgen (flutamide) monotherapy for locally advanced PrCa. Biochemical and molecular analyses showed hyperestrogenemia (serum estradiol = 266 pg/ml, with normal range < 74 pg/ml), germline BRCA-1 mutation (T to C at nucleotide 3232, in exon 11, causing Glu to Gly change at codon 1038) and chromosome 9 inversion (karyotype of 46,XY with inv(9) (p11q21)). Following bilateral mastectomy without adjuvant systemic therapy, the patient has been disease-free (from both BrCa and PrCa) for > 3 years. In contrast to LHRH-based hormonal therapies for PrCa, anti-androgen monotherapy causes hyper-estrogenemia due to the suppressed negative feedback loop of androgens on LHRH and LH production, stimulation of testicular androgen production and their intracrine transformation to estrogens in peripheral target tissues. In this case report, the hyperestrogenemia may have further increased the BrCa risk in a patient with other risk factors (BRCA-1 mutation and chromosome 9 inversion, which has been previously shown to impinge upon testicular function and intracrine balance of androgens vs. estrogens). This case report illustrates that PrCa patients receiving anti-androgen monotherapy may be at risk of BrCa, in the event of the concomitant presence of other genetically-determined predisposing factors, and indicates the importance of exercising caution against indiscriminate and prolonged use of anti-androgen monotherapy in patients with risk factors for male BrCa.

Glucocorticoid receptor function suppresses insulin-like growth factor 1 activity in human KLE endometrial-like cells.

We analysed the glucocorticoid receptor (GR) regulation on the expression of insulin-like growth factor 1 (IGF-1), type I IGF receptor (IGF-1.R), IGF-binding protein 3 (IGFBP-3), urokinase-type plasminogen activator (uPA) and uPA receptor (uPA.R) mRNA in human KLE endometrial-like cells. We documented that KLE cells express IGF-1, IGF-1.R, uPA and IGFBP-3 mRNA, however not uPA.R mRNA. Exogenous administration of dexamethasone inhibited the proliferation of KLE cells without inducing apoptosis. The inhibition of dexamethasone on KLE cell proliferation was neutralized by exogenous administration of IGF-1. Furthermore, dexamethasone suppressed the expression of IGF-1 mRNA and IGF-1.R mRNA as well as the IGF-1 bioavailability in KLE cell culture media, but it did not alter the expression of uPA mRNA and IGFBP-3 mRNA in KLE cells. Since the peritoneal fluid of women with endometriosis is known to contain IGF-1, which stimulates the proliferation and inhibits the apoptosis of endometrial-like cells, it is conceivable that GR-mediated down-regulation of IGF-1 bioavailability may be of clinical relevance for endometriosis.

Methods of detection of circulating melanoma cells: a comparative overview.

Disease dissemination is the major cause of melanoma-related death. A crucial step in the metastatic process is the intravascular invasion and circulation of melanoma cells in the bloodstream with subsequent development of distant micrometastases that is initially clinically undetectable and will eventually progress into clinically apparent metastasis. Therefore, the use of molecular methods to detect circulating melanoma cells may be of value in risk stratification and clinical management of such patients. Herein, we review the currently applied techniques for the detection, isolation, enrichment and further characterization of circulating melanoma cells from peripheral blood samples in melanoma patients. Furthermore, we provide a brief overview of the various molecular markers currently being evaluated as prognostic indicators of melanoma progression.

Molecular markers detecting circulating melanoma cells by reverse transcription polymerase chain reaction: methodological pitfalls and clinical relevance.

Herein, we expound the theory of circulating melanoma cells (CMCs) and their detection with reverse transcription polymerase chain reaction as a molecular staging approach. We discuss the molecular markers that have been used for CMC detection focusing on the use of these markers for multiplex detection analysis. Finally, we comment on the contradictory data of CMC detection studies in the literature and we propose possible solutions which may contribute to the clinical significance of CMC detection in patient management.

Detection of circulating tumor cells in bladder cancer patients.

The methods employed for the detection of circulating bladder cancer cells (CBCs) and their use as a molecular staging tool in clinical settings are thoroughly reviewed. CBC isolation and enrichment methods are discussed according to their advantages and pitfalls along with the clinical data of PCR-based techniques used for CBC detection. In addition, we review the specificity of molecular markers that have been proposed so far for CBC identification, and we comment on the controversial clinical data, proposing laboratory approaches which may improve the clinical significance of CBC detection in bladder cancer.

Rosiglitazone attenuates insulin-like growth factor 1 receptor survival signaling in PC-3 cells.

PPARgamma, a member of the peroxisome proliferator-activated receptor family, is overexpressed in prostate cancer. Natural and synthetic ligands of PPARgamma via genomic and nongenomic actions promote cell cycle arrest and apoptosis of several prostate cancer cells, in vitro. Insulin-like growth factor 1 (IGF-1) inhibits the adriamycin-induced apoptosis of PC-3 human prostate cancer cells. Therefore, we have analyzed the ability of two PPARgamma ligands,15dPGJ2 and rosiglitazone, a natural and a synthetic PPARgamma ligand, respectively, to increase the adriamycin-induced cytotoxicity of PC-3 cells and to suppress the IGF-1 survival effect on adriamycin-induced apoptosis of PC-3 cells. Our data revealed that both the PPARgamma ligands increased the adriamycin-induced cytostasis of PC-3 cells, however, only rosiglitazone added to the adriamycin-induced apoptosis of PC-3 cells. In addition, rosiglitazone attenuated the type I IGF receptor (IGF-1R) survival signaling on adriamycin-induced apoptosis of PC-3 cells via its nongenomic action on ERK1/2 and AKT phosphorylation. Because the IGF-1R signaling is probably the most important host tissue (bone) metastasis microenvironment-related survival signaling for prostate cancer cells, we conclude that rosiglitazone effects on IGF-1R-mediated activation of ERK1/2 and AKT could have clinical implications for the management of androgen ablation-refractory and chemotherapy-resistant advanced prostate cancer with bone metastasis.

The kisspeptin (KiSS-1)/GPR54 system in cancer biology.

Kisspeptin (KiSS-1) gene, initially described as a melanoma metastasis suppressor gene, encodes a number of peptides (kp-54, kp-14, kp-13, kp-10), which are endogenous ligands to a G protein-coupled receptor, referred as hOT7T175 or AXOR12 or GPR54. So far intensive investigation has provided substantiate evidence supporting the role of KiSS-1/GPR54 system in cancer biology as well as in the regulation of the reproductive function and trophoblast invasion. The precise mechanism by which KiSS-1/GPR54 system is affecting cancer cell growth and metastasis includes complex endocrine, paracrine and autocrine actions. Nevertheless, the detail mechanism of such actions is still under intensive investigation. Herein we review the evidence which support the role of KiSS-1/GPR54 system in cancer biology.

Experimental hyperthyroidism increases expression of parathyroid hormone-related peptide and type-1 parathyroid hormone receptor in rat ventricular myocardium of the Langendorff ischaemia-reperfusion model.

Parathyroid hormone-related peptide (PTHrP) is released under ischaemic conditions and it improves contractile function of stunned myocardium. The actions of PTHrP are mediated primarily by the type 1 parathyroid hormone receptor (PTH.1R), while PTHrP and PTH.1R expression levels are increased in ventricular hypertrophy associated with experimental hyperthyroidism. Since chronic administration of thyroxine (T4) improves postischaemic recovery in isolated heart models subjected to ischaemia-reperfusion stress, we tested the hypothesis that experimentally induced hyperthyroidism is associated with elevated expression of PTHrP and PTH.1R in rat myocardium. Hyperthyroid and control male Wistar rats were subjected to ischaemia-reperfusion stress using the Langendorff technique, and the PTHrP and PTH.1R expression was assessed by relative quantitative reverse transcriptase-polymerase chain reaction, Western blot analysis and immunohistochemistry. In the Langendorff model, the recovery of left ventricular developed pressure at the end of the stablization period and 45 min into the reperfusion period was used to assess the cardioprotective actions of T4 administration. Our data show that hyperthyroid animals had increased tolerance to the ischaemia-reperfusion stress and that this was associated with an increase of PTHrP and PTH.1R expression levels compared with those of control animals. In the control animals, the expression of PTHrP was increased 45 min into the reperfusion phase, while the PTH.1R expression pattern was significantly and gradually decreased throughout the ischaemia and reperfusion phases. In the hyperthyroid animals, the PTHrP and PTH.1R expression pattern was significantly higher throughout the ischaemia and reperfusion phases compared with that of control hearts. Our data suggest that increasing levels of PTHrP and PTH.1R expression can mediate, at least in part, the T4 administration-induced cardioprotection in rat ventricular myocardium.

Serum levels of the osteoprotegerin, receptor activator of nuclear factor kappa-B ligand, metalloproteinase-1 (MMP-1) and tissue inhibitors of MMP-1 levels are increased in men 6 months after acute myocardial infarction.

BACKGROUND: Osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) are critical regulators of bone remodeling and RANKL/RANK signaling could also play an important role in the remodeling process of several tissues, such as myocardium. Therefore, we investigated whether the serum concentrations of OPG and RANKL correlate with the serum levels of metalloproteinase-1 (MMP-1), MMP-9 and tissue inhibitors of MMP-1 (TIMP-1), which are known regulators of myocardial healing in acute myocardial infarction (AMI) patients. METHODS: We analyzed blood samples from 51 consecutively hospitalized men with AMI, 12 men with established ischemic heart failure (New York Heart Association category II, NYHA-II) and 12 healthy men age-matched to the NYHA-II patients. Serum levels of MMP-1, MMP-9, TIMP-1, OPG and RANKL were quantified using commercially available ELISA kits. AMI patients were sampled 4 days and 6 months after MI. RESULTS: Our data revealed increased serum levels of OPG, RANKL, MMP-1 and TIMP-1 levels and significant correlations between increased RANKL levels and MMP-1 and TIMP-1 serum levels 6 months after MI. In addition, the ratio OPG/RANKL was very low 6 months after MI, suggesting that the nuclear factor kappa-B signaling is possibly more active 6 months post-MI than it is on day 4 post-MI. CONCLUSIONS: Our data suggest that OPG, RANKL, MMP-1 and TIMP-1 serum levels can be potential mediators of myocardial healing after MI. However, further large studies are needed to confirm the utility of OPG and RANKL as markers of healing after ST elevation in MI.