Biomedical subjects

Michael Koutsilieris

Publications and source records attributed to Michael Koutsilieris.

30 records · Page 2Linked to original sources

PubMedDate not supplied

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.

Adenocarcinoma↗

PubMedDate not supplied

Three-dimensional culture system as a model for studying cancer cell invasion capacity and anticancer drug sensitivity.

BACKGROUND: Three-dimensional (3-D) culture systems that simulate the tumor extracellular microenvironment may be appropriate to test cancer cell potential for invasion and tumor cell sensitivity to anticancer drugs. MATERIALS AND METHODS: Human PC-3 prostate, A549 colon, HT-29 lung and MCF-7 and MDA-MB231 breast cancer cells were embedded and grown in collagen gel surrounded by a fibrin clot. Increasing concentrations of cisplatin, doxorubicin, paclitaxel and 5-fluorouracil were comparatively evaluated for their ability to inhibit tumor cell proliferation and colony formation in vitro. RESULTS: All cells, except MDA, formed colonies in collagen. PC-3, A549 and HT-29 cells massively invaded fibrin forming migratory fronts. Cell colonies were also formed in fibrin (secondary tumor-like structures) apart from migratory fronts; HT-29 cells were the most aggressive in this regard MDA cells were particularly sensitive to doxorubicin, while MCF-7 cells showed sensitivity to all anticancer regimens tested. A549 cells were the tumor cell type with greatest potential for invasion and were sensitive mostly to cisplatin. PC-3 cells were primarily sensitive to cisplatin and doxorubicin, while HT-29 cells were sensitive to fluorouracil and doxorubicin. CONCLUSION: 3-D collagen cell culture systems can be used to study cancer cell potential for invasion and their relative sensitivity/resistance to anticancer drugs.

Adenocarcinoma↗

PubMedDate not supplied

Boosting the immune response: an alternative combination therapy for cancer patients.

Transformation of normal cells into malignant cancer involves a number of changes in the genome. These changes include chromosomal translocations, exon deletions and gene mutations, to name a few, that result in deregulation of the regulatory circuits of the cell and consequently in profound changes in their antigenic composition, including expression of mutated proteins, overexpression of proteins that are produced at much lesser levels in normal tissue and expression of aberrantly glycosylated proteins. It is well established that these new antigenic entities, referred to as tumor-associated antigens (TAA), are recognized by the immune system and elicit immune reactivity. However, the immune reaction is overpowered by the cancer potential to grow and to metastasize. Cancer immunotherapy aims at boosting the naturally occurring immune response at a level that will prevail over the ability of cancer cells to escape immune attack. After more than 20 years of intense research and a growing number of clinical trials, most of which gave marginal results, it is now clear that the task is not an easy one. However, during the same period of time, we have gained a much better understanding of the mechanisms of tumor growth, the mechanisms by which the immune system is activated or becomes tolerant and of the natural relationship between cancers and the immune system. Also, even though few, some immunotherapy strategies have demonstrated positive clinical responses and are already used as standard therapies. These developments give the impetus to explore and devise new strategies that will by more effective in strengthening the immune reactivity at a level that will counteract the tumor potential. In this paper we review the knowledge gained from basic research related to cancer immunity and from clinical trials. We propose that, based on this knowledge, improved clinical protocols can be elaborated.

Animals↗

PubMedDate not supplied

Glutamatergic system in bone physiology.

Bone is a highly innervated tissue consisting of nerve fibers, which contain many neurotransmitters including glutamate. Recently, a number of studies have identified functional glutamate receptors in osteoblasts and osteoclasts, implying that the glutamatergic system has an apparent regulatory role in bone physiology. This review outlines the evidence which suggest that the glutamatergic system regulates bone physiology.

Animals↗

PubMedDate not supplied

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.

Amino Acid Transport System X-AG↗

PubMedDate not supplied

Immunohistochemical expression of Bcl2 is an independent predictor of time-to-biochemical failure in patients with clinically localized prostate cancer following radical prostatectomy.

BACKGROUND: Whether the immunohistochemical expression (IHCE) of the bcl2, the p53 and of the prostate apoptosis response-4 (PAR4) proteins is associated with pre-operative PSA levels, post-operative parameters of prostate cancer (PC) pathology, surgical staging or biochemical failure (BF) of patients with clinically localized PC who underwent radical prostatectomy (RP) of curative intent, was investigated. PATIENTS AND METHODS: A retrospective analysis of clinical data evaluating surgical specimens of 131 patients with PC, consecutively treated with RP for clinically localized disease, was performed. The IHC method of streptavidin biotin peroxidase on paraffin tissue sections was used to detect bcl2 and p53 oncoproteins and PAR4 pro-apoptotic protein expression in surgical specimens. RESULTS: Statistically significant relationships were detected between: (i) p53 IHC expression and infiltration of periprostatic tissue (IPT; p = 0.011); (ii) tumor volume (TV; p = 0.027); and (iii) bcl2 IHCE and absence of prostatic intraepithelial neoplasia (PIN) (p = 0.004). Biochemical failure (BF) was documented in 37% of these patients. Kaplan-Meier survival curves showed that the IHCE of bcl2 and p53 was significantly related to BF. Taking the hazard ratio (HR) estimated from the Cox proportional hazard regression model to be 1.00 for patients with negative bcl2 IHCE, a value of 2.82 was found for patients with positive bcl2 IHCE (p = 0.015, 95% CI = 1.22-6.47). The HR for patients with positive p53 IHCE was 2.05 (p = 0.048, 95% CI = 1.00-4.19). Multivariate analysis showed that only seminal vesicle invasion (SVI), pelvic lymph node metastasis (PLNM) and bcl2 IHCE were independent predictors for BF (HR = 3.06, 3.31 and 3.15; p = 0.048, p = 0.031 and p = 0.031 for SVI, PLNM and bcl2 IHCE, respectively). CONCLUSION: Bcl2 immunohistochemical overexpression in specimens of RP suggests high risk for BF in clinically localized PC.

Biomarkers, Tumor↗

PubMedDate not supplied

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.

Cell Differentiation↗

PubMedDate not supplied

p27(kip1) and Ki-67 (MIB1) immunohistochemical expression in radical prostatectomy specimens of patients with clinically localized prostate cancer.

The immunohistochemical expressions (IE) of p27(kip1) and Ki-67 (MIB-1), both involved in cell cycle regulation and cell proliferation, and their ability to predict biochemical failure, were assessed in patients with clinically localized prostate cancer who had underdone radical prostatectomy of curative intent. In addition, p27(kip1) and Ki-67 (MIB1) expressions were correlated with several pre-operative and post-operative parameters, such as Gleason score, extracapsular extension, seminal vesicle involvement, pelvic lymph nodes metastasis, positive surgical margins, coexistence of high-grade prostatic intraepithelial neoplasia, tumour size, prostate volume and PSA levels. Our analysis involved 130 consecutive radical prostatectomy specimens. A statistically significant correlation of low p27(kiP1) IE with seminal vesicles involvement, increased tumour volume and high pre-operative PSA values was documented. Low p27(kiP1) IE was significantly correlated with an increased likelihood of biochemical failure after radical prostatectomy. In addition, the increased IE of Ki-67 (MIB1) correlated significantly with metastatic disease in the pelvic lymph nodes and was a significant predictor of biochemical failure. Cox regression analysis, which included p27(kip1) expression, Ki-67 (MIB1) expression and all the pre-operative and post-operative parameters, showed that pelvic lymph node involvement and Ki-67 (MIB1) IE were independent prognostic markers of biochemical failure after radical prostatectomy.

Aged↗

PubMedDate not supplied

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.

Bone Density Conservation Agents↗

PubMedDate not supplied

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.

Aged↗

PubMedDate not supplied

Randomized controlled clinical trial of a combination of somatostatin analog and dexamethasone plus zoledronate vs. zoledronate in patients with androgen ablation-refractory prostate cancer.

BACKGROUND: As previously shown, the combination of standard androgen ablation therapy with somatostatin analog and dexamethasone in metastatic androgen ablation-refractory (stage D3) prostate cancer (PrCa) patients has a favorable profile of side-effects, durable objective antitumor activity (up to 60% partial response rate) and palliative effects. Bisphosphonates interfere with bone remodeling at the sites of PrCa bone metastases and have been postulated to have indirect and/or direct anti-PrCa activity. MATERIALS AND METHODS: A randomized controlled clinical trial was conducted to compare a combination of somatostatin analog (octreotide 20 mg i.m. every 28 days) and oral dexamethasone (4 mg daily for 1 month, gradually reduced to 1 mg daily by the fourth month, with a 1 mg daily maintenance dose thereafter) plus zoledronate (4 mg i.v. every 4 weeks) vs. zoledronate only. All patients in both arms remained in basic androgen blockade throughout the study. RESULTS: Thirty-eight stage D3 patients (mean age 72.8 +/- 6.8 years) were randomized to either treatment arm of the study. The trial was stopped after a pre-specified interim analysis met the criteria for early closure, i.e. significant difference in outcomes between the two treatment arms. Partial responses (PR, > or =50% PSA decline) were observed in 13 out of 20 patients with combination therapy vs. none with zoledronate. The combination therapy arm had significantly better outcome with respect to median progression-free survival (7.0 vs. 1.0 months, p < 0.0001), median overall survival (OS) (12.0 vs. 9.0 months, p = 0.0027), median PrCa-specific OS (defined as time from onset of therapy until PrCa-related death) (16 vs. 9.0 months, p = 0.0005) and median duration of bone pain improvement (>14 vs. 4 months p = 0.00001 by log-rank tests). CONCLUSION: For androgen ablation-refractory metastatic PrCa patients under androgen ablation, the combination of dexamethasone, somatostatin analog and zoledronate offered superior objective and palliative clinical responses than zoledronate alone.

Aged↗

PubMedDate not supplied

The PTHrP/PTH.1-R bioregulation system in cardiac hypertrophy: possible therapeutic implications.

Myocardial hypertrophy is associated with specific histological changes, which are representative of the cardiomyocytes cellular response to overload. Evidently, transcriptional modulation of specific genes is implicated in myocardial hypertrophy. Recently, the parathyroid hormone-related protein (PTHrP)/PTH-1 receptor (PTH-1.R) bioregulation system was shown to participate in specific regulatory processes of the cardiomyocyte function and proliferation, which can be related to cardiac hypertrophy and heart failure. We review the literature on the pathophysiology of cardiac hypertrophy vis-a-vis the role of PTHrP/PTH-1.R system as a good therapeutic target.

Animals↗