Penelope Korkolopoulou

Laiko Hospital, Athínai, Attica, Greece

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Publications (98)316.34 Total impact

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    ABSTRACT: We investigated the significance of PI3K/AKT/mTOR pathway and its interactions with MAPK, JAK/STAT and Notch pathways in meningioma progression. Paraffin-embedded tissue from 108 meningioma patients was analysed for the presence of mutations in PIK3CA and AKT1. These were correlated with the expression status of components of the PI3K/AKT/mTOR pathway, including p85α and p110γ subunits of PI3K, phosphorylated (p)-AKT, p-mTOR, p-p70S6K and p-4E-BP1, as well as of p-ERK1/2, p-STAT3 and Notch-1, clinicopathological data and patient survival. A mutation in PIK3CA or AKT1 was found in around 9 % of the cases. Higher grade meningiomas displayed higher nuclear expression of p-p70S6K; higher nuclear and cytoplasmic expression of p-4E-BP1 and of Notch-1; lower cytoplasmic expression of p85αPI3K, p-p70S6K and p-ERK1/2; and lower PTEN Histo-scores (H-scores). PTEN H-score was inversely correlated with recurrence probability. In univariate survival analysis, nuclear expression of p-4E-BP1 and absence of p-ERK1/2 expression portended adverse prognosis, whereas in multivariate survival analysis, p-ERK1/2 expression emerged as an independent favourable prognostic factor. Treatment of the human meningioma cell line HBL-52 with the PI3K inhibitor LY294002 resulted in reduction of p-AKT, p-p70S6K and p-ERK1/2 protein levels. The complex interactions established between components of the PI3K/AKT/mTOR pathway, or with components of the MAPK, JAK/STAT and Notch-1 pathways, appear to be essential for facilitating and fuelling meningioma progression.
    Virchows Archiv : an international journal of pathology. 08/2014;
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    ABSTRACT: The polycystins PC1 and PC2 are emerging as major players in mechanotransduction, a process that influences all steps of the invasion/metastasis cascade. We hypothesized that PC1 and PC2 facilitate cancer aggressiveness. Immunoblotting, RT-PCR, semi-quantitative and quantitative real-time PCR and FACS analyses were employed to investigate the effect of polycystin overexpression in colorectal cancer (CRC) cells. The impact of PC1 inhibition on cancer-cell proliferation was evaluated through an MTT assay. In vitro data were analyzed by Student t test. HT29 human xenografts were treated with anti-PC1 (extracellular domain) inhibitory antibody and analyzed via immunohistochemistry to determine the in vivo role of PC1 in CRC. Clinical significance was assessed by examining PC1 and PC2 protein expression in CRC patients (immunohistochemistry). In vivo and clinical data were analyzed by non-parametric tests, Kaplan-Meier curves, log-rank test and Cox model. All statistical tests were two-sided. PC1 overexpression promotes epithelial-to-mesenchymal transition (EMT) in HCT116 cells, while PC2 overexpression results in upregulation of the mTOR pathway in SW480 cells. PC1 inhibition causes reduced cell proliferation in CRC cells inducing tumor necrosis and suppressing EMT in HT29 tumor xenografts. In clinical study, PC1 and PC2 overexpression associates with adverse pathological parameters, including invasiveness and mucinous carcinomas. Moreover, PC1 overexpression appears as an independent prognostic factor of reduced recurrence-free survival (HR=1.016, p=0.03) and lowers overall survival probability, while aberrant PC2 expression predicts poor overall survival (p=0.0468). These results support, for the first time, a direct link between mechanosensing polycystins (PC1 and PC2) and CRC progression. © 2014 Wiley Periodicals, Inc.
    International Journal of Cancer 08/2014; · 6.20 Impact Factor
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    ABSTRACT: Obesity represents a route to broad physiological dysfunction affecting major organs including male urogenital system. Hyperglycemia, hyperlipidemia, and oxidative stress associated with obesity augment the formation of reactive metabolic by-products, namely advanced glycation end products (AGEs), leading to increased tissue deposition and damage. The exogenous intake and the endogenous accumulation of AGEs contribute to metabolic and reproductive abnormalities in both women and men. The present study assessed the effects of a diet high in saturated fatty acids (SAFA) on the lipid and metabolic profile (AGE levels, oxidative stress) as well as pathogenic (AGE, receptor for AGEs [RAGE] expression, apoptosis) and morphometric parameters of male reproductive system in vivo. Effects of switching to a diet rich in monounsaturated fatty acids (MUFA) or equal in the proportion MUFA to SAFA were further investigated. SAFA-fed animals were characterized by increased serum lipid concentrations (p < .05) compared to controls, but AGEs and peroxide levels were not significantly different across the different experimental groups. Elevated AGE deposition was detected for the first time in germ cells with a higher staining intensity in animals on the SAFA diet, compared to MUFA or MUFA-SAFA-fed animals or the control samples (p = .018). In Leydig cells, AGE localization was higher in the entire cohort of high-fat-fed animals compared to controls (p < .05). High-fat-fed mice displayed enhanced apoptosis compared to controls (p < .005). Furthermore, prostatic tissue demonstrated reduction in epithelial folding, an effect which was significantly reversed after MUFA diet administration. Our findings provide the basis for further investigation of AGE-RAGE axis in testicular and prostatic disturbances associated with diet-induced obesity. Simple dietetic intervention has beneficial effects on metabolic dysfunction of reproductive system before overt manifestations, indicating glycation as a promising therapeutic target.
    Experimental biology and medicine (Maywood, N.J.). 05/2014;
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    ABSTRACT: Epigenetic mechanisms participate in melanoma development and progression. The effect of histone modifications and their catalyzing enzymes over euchromatic promoter DNA methylation in melanoma remains unclear. The present study investigated the potential association of p16(INK) (4A) promoter methylation with histone methyltransferase SETDB1 expression in Greek patients with sporadic melanoma and their correlation with clinicopathological characteristics. Promoter methylation was detected by methylation-specific PCR in 100 peripheral blood samples and 58 melanoma tissues from the same patients. Cell proliferation (Ki-67 index), p16(INK) (4A) and SETDB1 expression were evaluated by immunohistochemistry. High-frequency promoter methylation (25.86%) was observed in tissue samples and correlated with increased cell proliferation (p=0.0514). p16(INK) (4A) promoter methylation was higher in vertical growth phase (60%) melanomas than in radial (40%, p=0.063) and those displaying epidermal involvement (p=0.046). Importantly, p16(INK) (4A) methylation correlated with increased melanoma thickness according to Breslow index (p=0.0495) and marginally with increased Clark level (I/II vs III/IV/V, p=0.070). Low (1-30%) p16(INK) (4A) expression was detected at the majority (19/54) of melanoma cases (35.19%), being marginally correlated with tumor lymphocytic infiltration (p=0.078). SETDB1 nuclear immunoreactivity was observed in 47/57 (82.46%) cases, whereas 27/57 (47.37%) showed cytoplasmic immunoexpression. Cytoplasmic SETDB1 expression correlated with higher frequency of p16(INK) (4A) methylation and p16(INK) (4A) expression (p=0.033, p=0.011, respectively). Increased nuclear SETDB1 levels were associated with higher mitotic count (0-5/mm(2) vs >5/mm(2) , p=0.0869), advanced Clark level (III-V, p=0.0380), epidermal involvement (p=0.0331) and the non-chronic sun exposure associated melanoma type (p=0.0664). Our data demonstrate for the first time the association of histone methyltransferase SETDB1 with frequent methylation of the euchromatic p16(INK) (4A) promoter and several prognostic parameters in melanomas. This article is protected by copyright. All rights reserved.
    Experimental Dermatology 03/2014; · 3.58 Impact Factor
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    ABSTRACT: Chemokine receptor signaling pathways are implicated in the pathobiology of renal cell carcinoma (RCC). However, the clinical relevance of CXCR2 receptor, mediating the effects of all angiogenic chemokines, remains unclear. SOCS (suppressor of cytokine signaling)-3 is a negative regulator of cytokine-driven responses, contributing to interferon-alpha resistance commonly used to treat advanced RCC with limited information regarding its expression in RCC. In this study, CXCR2 and SOCS-3 were immunohistochemically investigated in 118 RCC cases in relation to interleukin (IL)-6 and (IL)-8, their downstream transducer phosphorylated (p-)STAT-3, and VEGF expression, being further correlated with microvascular characteristics, clinicopathological features and survival. In 30 cases relationships with hypoxia-inducible factors, i.e. HIF-1a, p53 and NF-kappaBeta (p65/RelA) were also examined. Validation of immunohistochemistry and further investigation of downstream transducers, p-JAK2 and p-c-Jun were evaluated by Western immunoblotting in 5 cases. Both CXCR2 and IL-8 were expressed by the neoplastic cells their levels being interrelated. CXCR2 strongly correlated with the levels of HIF-1a, p53 and p65/RelA in the neoplastic cells. Although SOCS-3 was simultaneously expressed with p-STAT-3, its levels tended to show an inverse relationship with p-JAK-2 and p-c-Jun in Western blots and were positively correlated with HIF-1a, p53 and p65/p65/RelA expression. Neither CXCR2 nor SOCS-3 correlated with the extent of microvascular network. IL-8 and CXCR2 expression was associated with high grade, advanced stage and the presence/number of metastases but only CXCR2 adversely affected survival in univariate analysis. Elevated SOCS-3 expression was associated with progression, the presence/number of metastasis and shortened survival in both univariate and multivariate analysis. Our findings implicate SOCS-3 overexpression in RCC metastasis and biologic aggressiveness advocating its therapeutic targeting. IL-8/CXCR2 signaling also contributes to the metastatic phenotype of RCC cells but appears of lesser prognostic utility. Both CXCR2 and SOCS-3 appear to be related to transcription factors induced under hypoxia.
    BMC Cancer 03/2014; 14(1):149. · 3.33 Impact Factor
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    ABSTRACT: Angiogenesis leads to new blood vessel formation and is implicated in both physiological and pathological situations. The vascular endothelial growth factor (VEGF) family is the major mediator of this process. The aim of our study was to evaluate the expression of VEGF-A, vascular endothelial growth factor receptor-1 (VEGFR-1) and VEGFR-2 and their correlation with clinicopathological parameters and prognosis in patients with classical Hodgkin lymphoma (cHL), since the role of angiogenesis in this tumor still remains unclear. The immunohistochemical expression of VEGF-A, VEGFR-1 and VEGFR-2 was examined in 194 patients with cHL. The neoplastic Hodgkin Reed–Sternberg (HRS) cells expressed VEGF-A, VEGFR-1 and VEGFR-2 in 90.3%, 97.2% and 94.1% of cases, respectively. Only the expression of VEGFR-2 was positively correlated with serum albumin levels ≥ 4 g/dL. No correlation with patient outcome was observed. All three molecules were statistically correlated with ramifications of blood vessels. Summarizing, our results are not sufficient to consider VEGF-A and/or VEGF receptors as prognosticators in cHL.
    Leukemia and Lymphoma 01/2014; 55(3). · 2.61 Impact Factor
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    ABSTRACT: A number of studies have looked into the pathophysiological role of angiogenesis in CLL, but the results have often been inconsistent. We aimed to gain direct insight into the angiogenic process in lymph nodes involved by CLL, focusing on proangiogenic cytokines and microvessel morphometry. The tissue levels of VEGF, Th-2 cytokines IL-6 and IL-8, IL-8 receptor CXCR2, and tyrosine p-STAT-3/SOCS-3 axis modulating cytokine expression were evaluated immunohistochemically in 62 CLL/SLL cases. Microvascular characteristics were evaluated by image analysis. Results were analyzed with regard to clinicopathological characteristics. Proliferation centers (PCs) were less well vascularised compared to non-PC areas. IL-8 and CXCR2 expression was distinctly uncommon as opposed to IL-6, VEGF and SOCS-3, which were detected in the vast majority of cases. The latter two molecule expressions were more pronounced in the PCs in ∼40% of the cases. p-STAT-3 immunoreactivity was recorded in 66.67% of the cases with a predilection for PCs. Microvessel morphometry was unrelated to proangiogenic cytokines, p-STAT-3, SOCS-3, or survival. Microvascular caliber and VEGF expression were higher in Binet stage A, whereasIL-6 expression was higher in stage C. VEGF and p-STAT-3 exerted a favorable effect on progression, which remained significant in multivariate analysis, thereby constituting potential outcome predictors in CLL patients.
    BioMed Research International 01/2014; 2014:251479. · 2.88 Impact Factor
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    ABSTRACT: The biological and clinical significance of a clonal B-cell lymphocytosis with an immunophenotype consistent with marginal zone origin (CBL-MZ) is poorly understood. We retrospectively evaluated 102 such cases with no clinical evidence to suggest a concurrent MZ lymphoma. Immunophenotyping revealed a clonal B-cell population with Matutes score ≤2 in all cases; 19/102 were weakly CD5-positive and all 35 cases tested expressed CD49d. Bone marrow biopsy exhibited mostly mixed patterns of small B-lymphocytic infiltration. 48/66 (72.7%) cases had an abnormal karyotype. Immunogenetics revealed overusage of the IGHV4-34 gene and somatic hypermutation in 71/79 (89.8%) IGHV-IGHD-IGHJ gene rearrangements. With a median follow-up of 5 years, 85 cases remain stable (Group A), whereas 17 cases (Group B) progressed, of whom 15 developed splenomegaly. Neither the clonal B-cell count, degree of marrow infiltration, immunophenotypic nor immunogenetic findings at diagnosis distinguished between the 2 groups. However deletions of chromosome 7q were confined to Group A and complex karyotypes were more frequent in Group B. Although CBL-MZ may antedate SMZL/SLLU, most cases remain stable over time. These cases, not readily classifiable within the WHO classification, raise the possibility that CBL-MZ be considered as a new provisional entity within the spectrum of clonal marginal zone disorders.
    Blood 12/2013; · 9.78 Impact Factor
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    ABSTRACT: To investigate the prevalence of autoimmune gastritis, Enterochromaffin-like cell (ECL-cell) hyperplasia and Gastric Neuroendocrine tumours type 1 (GNET1) in patients with autoimmune thyroid disease. Prospective observational study in a single institutional study. 120 patients with autoimmune thyroid disease were consecutively recruited from the Endocrine Clinic. Upper gastrointestinal tract endoscopy (UGE) and biochemical parameters for autoimmune thyroid disease and autoimmune gastritis were assessed at recruitment and annually thereafter in patients with a mean follow-up 37.5±14.4months. Autoimmune gastritis was defined by the presence of anti-parietal cell antibodies (APCA) and histological confirmation after UGE. Serum gastrin and chromogranin Α were also measured. 111 patients had Hashimotos' thyroiditis and 9 Graves' disease. Autoimmune gastritis was identified in 40 (38 with Hashimotos' thyroiditis, 2 with Graves' disease) patients all of whom had increased levels of gastrin and chromogranin Α; Helicobacter pylori infection was histologically identified in 15/40 (37.5%). Six patients had isolated nodular ECL-cell hyperplasia and one mixed nodular and linear ECL-cell hyperplasia [7/40 (17.5%)]. Only increased gastrin (p=0.03) levels predicted the presence ECL-cell hyperplasia. A GNET1 developed in one patient with nodular ECL-cell hyperplasia after 39 months of follow-up. Concomitant autoimmune gastritis was found in 33.3% of patients with autoimmune thyroid disease, 17.5% of whom had ECL-cell hyperplasia that evolved to GNET1 in one (2.5%). Larger studies with longer follow-up are needed to define the incidence of GNET1 in patients with autoimmune thyroid disease and ECL-cell hyperplasia and potential implications. This article is protected by copyright. All rights reserved.
    Clinical Endocrinology 10/2013; · 3.40 Impact Factor
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    ABSTRACT: The phosphoinositide 3-kinase (PI3K)/v-akt murine thymoma viral oncogene homolog (AKT)/mammalian target of rapamycin (mTOR) pathway is upregulated in a number of human cancers, including non-small cell lung cancer (NSCLC). Its potential role in NSCLC progression provides an attractive target for anticancer therapy. The expression of phosphorylated mTOR (p-mTOR), phosphorylated AKT (p-AKT), p85α and p110γ subunits of PI3K, phosphorylated p70S6K (p-p70S6K), phosphatase and tensin homolog (PTEN) and phosphorylated 4E-BP1 (p‑4E‑BP1) was examined by immunohistochemistry in 102 NSCLC specimens. The results were correlated with clinicopathological features. We also examined 61 of our cases for the presence of PIK3CA, AKT1, PTEN and K-RAS mutations. A common PIK3CA mutation was detected at exon 9 in 2 samples (p.E545K), whereas another sample displayed a rare mutation (p.D1018N). Furthermore, 10 out of 54 cases (18.5%) had a K-RAS mutation at codon 12, 5 had a PTEN mutation (exons 7 and 8) and 1 case had an AKT1 mutation (p.E17K). PTEN mutations were associated with nodal metastases. The expression of p-mTOR positively correlated with that of p-AKT and p-p70S6K and was higher in adenocarcinomas along with nuclear p110γPI3K expression, whereas p-4E-BP1 expression was higher in squamous cell carcinomas. We also established a positive association between p85αPI3K or p110γPI3K and cytoplasmic p-AKT and its downstream effectors. An inverse correlation was noted between p-4E-BP1 immunoexpression and tumour status and nuclear p-AKT expression as regards tumour stage. Univariate survival analysis demonstrated that p-4E-BP1 expression, either alone or in combination with cytoplasmic p-AKT expression had an adverse prognostic significance in adenocarcinomas. The combination of p-4E‑BP1 and cytoplasmic p-AKT expression remained significant in the multivariate analysis as a function of their interaction with histological type. Our data demonstrate the significance of p‑4E‑BP1 immunoexpression as a molecular marker of prognostic value in adenocarcinomas, particularly when combined with p-AKT.
    Oncology Reports 05/2013; · 2.30 Impact Factor
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    ABSTRACT: ABSTRACT We have analyzed the immunohistochemical expression of a wide range of molecules, along with the proliferation rate separately in the proliferation centers (PCs) and in the rest of tumor area on lymph node or spleen sections of CLL patients. Fas, FasL and c-FLIP were observed both within and outside the PCs in all cases. However only the difference in FasL expression between the PCs and the non-PC areas attained statistical significance. Median survivin expression in the PCs was higher compared to the non-PC areas. Cleaved-caspase 3 was expressed in very low levels both within and outside PCs while the BCL-2 protein was expressed in high levels in all cases in both tumor compartments. Multivariate analysis demonstrated that concurrent overexpression of Fas/FasL/c-FLIP in the PCs was correlated with worse outcome for progression free survival as well as for overall survival.
    Leukemia & lymphoma 05/2013; · 2.61 Impact Factor
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    ABSTRACT: BACKGROUND: Although the expression pattern of phosphorylated (p)-mTOR pathway components has attracted scientific interest in several neoplasms, to our knowledge, there is no published information regarding its significance in mycosis fungoides (MF). OBJECTIVE: We sought to perform a comprehensive simultaneous assessment of key members of AKT/mTOR pathway along with p-extracellular signal-regulated kinase (ERK), NOTCH1, and p-STAT3 in patients with MF. METHODS: In all, 54 skin biopsy specimens (21 tumors, 30 plaques, and 3 folliculotropic MF) from 50 patients with MF were analyzed immunohistochemically for p-mTOR, its upstream p-AKT, its downstream effectors p-p70S6K and p-4E-BP1, and for p-ERK1/2, NOTCH1, and p-STAT3. RESULTS: p-mTOR was coexpressed with p-p70S6K in 67.3% of lesions, but coexpression with other molecules was less common. p-p70S6K and marginally NOTCH1 displayed higher H-scores in tumors than in plaques. Significant correlations were recorded between p-ERK and p-4E-BP1, as well as between NOTCH1 and p-p70S6K or p-4E-BP1. NOTCH1, p-4E-BP1, and p-p70S6K expression were associated with advanced stage. In survival analysis simultaneous overexpression of p-AKT and p-p70S6K, along with p-4E-BP1 positivity, adversely affected cancer-specific, disease-free, and progression-free survival in advanced-stage cases. LIMITATIONS: A limitation may be the small number of cases included in our investigation, precluding multivariate survival analysis. CONCLUSIONS: Activation of AKT/mTOR pathway in MF appears to be correlated with NOTCH1, p-ERK, and p-STAT3 and is implicated in the acquisition of a more aggressive phenotype. The combination of p-AKT, p-p70S6K, and p-4E-BP1 emerges as a significant potential prognostic marker in patients with advanced stage.
    Journal of the American Academy of Dermatology 05/2013; · 4.91 Impact Factor
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    ABSTRACT: : To investigate the expression of tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and osteoprotegerin (OPG) in bladder urothelial carcinomas (UCs) and assess possible interrelations with other regulators of TRAIL induced apoptosis (p65/NF-κB, p-ERK1/2, p-AKT) and FGFR3, as well as to elucidate their potential involvement in bladder tumourigenesis and determine their potential prognostic utility. : Paraffin embedded transurethral resection tissue from 128 patients with UC was immunostained for TRAIL and OPG as well as for p65/NF-κB, p-ERK1/2, p-AKT and FGFR3. : TRAIL and OPG were coexpressed in 96.6% of cases and positively interrelated. OPG expression was significantly different among histological grades, being higher in low-grade UCs and was inversely correlated with the presence of lymphovascular invasion (LVI). TRAIL also displayed an inverse relationship with histological grade, T-category and LVI. Both OPG and TRAIL expression were positively correlated with FGFR3 expression, the former relationship being marginal. Moreover, increased TRAIL expression was marginally correlated with lower NF-κB/p65 nuclear expression. Increased OPG expression adversely affected survival both in univariate and multivariate analysis. : OPG and TRAIL are frequently expressed and coexpressed in UCs, supporting the involvement of OPG in the resistance to TRAIL-driven apoptosis. Inhibition of NF-κB activation may also play a similar role, although less important. OPG emerged as an independent prognostic marker of adverse significance.
    Pathology 02/2013; 45(2):138-44. · 2.66 Impact Factor
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    ABSTRACT: Background. Treatment of splenic marginal zone lymphoma (SMZL) patients is not standardized. Recent data suggest that rituximab is highly effective and could be considered as initial therapy.Aim. To assess the efficacy of rituximab monotherapy in a large series of patients with SMZL and compare these results with splenectomy results.Methods. The studied population included 85 patients. Fifty-eight received rituximab at a dose of 375 mg/m(2) per week for 6 weeks as induction followed by maintenance at the same dose every 2 months for 1-2 years, whereas 27 patients were treated using splenectomy only.Results. The overall response rate to rituximab 2 months after the end of induction was 95% (complete response [CR], 45%; unconfirmed CR, 26%; partial response, 24%). The median times to hematologic and clinical response were 2 weeks and 3 weeks, respectively. Forty-three of 55 patients already completed the maintenance phase: 28 sustained their initial response, 14 improved their response, and one progressed. Eighty-five percent of splenectomized patients responded, and two were treated with rituximab as consolidation after splenectomy and achieved a CR. The 5-year overall and progression-free survival (PFS) rates for rituximab-treated and splenectomized patients were 92% and 77% (p = .09) and 73% and 58% (p = .06), respectively. Furthermore, maintenance therapy with rituximab resulted in a longer duration of response (at 5 years, PFS was 84% for patients receiving maintenance and 36% for patients without maintenance, p <.0001).Conclusions. Rituximab is a very effective and well-tolerated therapy and may be substituted for splenectomy as the first-line treatment of choice for patients with SMZL.
    The Oncologist 01/2013; · 4.10 Impact Factor
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    ABSTRACT: Neovascularisation is a vital process underlying the development and progression of malignant neoplasms. Limited information on the subject is available regarding Waldenstrom’s macroglobulinemia/Lymphoplasmacytic lymphoma (WM/LPL), a rare and usually indolent B-cell lymphoma. We therefore studied by immunohistochemistry microvessel characteristics and IL-6, IL-8, CXCR2 and VEGF expression in the bone marrow of WM/LPL patients and investigated any possible correlation with disease characteristics and outcome. Sixty-three patients were studied (47 WM and 16 LPL) of whom 32, 25 and 6 were low, intermediate and high risk respectively, according to the IPSSWM staging system. Seventy-six percent of the patients required treatment while 24% were asymptomatic and were regularly followed- up. Microvascular characteristics, i.e microvessel density (MVD), total vascular area (TVA) and several other sizeand shape-related parameters, were evaluated in CD34-stained bone marrow slides using computerized image analysis. A Histo-score (H-score) was calculated for IL-6, IL-8, CXCR2 and VEGF expression. IL-6, IL-8, IL-8 receptor CXCR2 and VEGF expression was observed in 84%, 43%, 89% and 90% respectively. A positive correlation between IL-6 and CXCR2 H-scores was observed; IL-6 and VEGF H-scores correlated with hypoalbulinemia and increased serum β2- microglobulin respectively and both with bone marrow lymphoplasmacytic infiltration and MVD. The degree of angiogenesis, microvessel shape, VEGF expression and CXCR2 expression correlated with a shorter time to first treatment in multivariate analysis. In conclusion, in WM/LPL, increased expression of Th-2 cytokines, CXCR2 and VEGF is implicated in neovascularization. CXCR2 and VEGF expression along with the extent and the architecture of the microvessels are brought forward as contributors to biologic aggressiveness reflected by a need for earlier treatment.
    Current Angiogenesis. 01/2013; 2(2).
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    ABSTRACT: What's known on the subject? and What does the study add? A few published studies investigating single or various PI3K/AKT/mTOR signalling components have produced inconsistent results. Moreover, PI3K regulatory subunit p85a and activated p70S6K expression levels have not been previously examined in urothelial carcinoma (UC). The present study addresses simultaneously all key members of PI3K/AKT/mTOR signalling cascade supporting a differential implication of PI3K/AKT/mTOR pathway components in urothelial tumorigenesis. Furthermore, we propose p-4E-BP1 as a potential prognostic marker in UC, which might assist the selection of patients more likely to benefit from chemotherapy regimens based on PI3K/AKT/mTOR pathway inhibition. Finally, the present study indicates PIK3CA/AKT1 mutational status as a potential predictive marker for time-to-recurrence. OBJECTIVE: •  To perform a comprehensive simultaneous assessment of all key members of phosphoinositide 3-kinase/v-akt murine thymoma viral oncogene/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway along with AKT homolog 1 (AKT1) and PIK3 catalytic alpha polypeptide (PIK3CA) mutations in bladder urothelial carcinoma (UC). •  Published information is limited to a few studies looking into single or various combinations of members of this pathway with inconsistent results. In particular the expression status of phosphorylated (p-)p70S6 kinase (p70S6K) and p85a subunit of PI3K has not been tested in UC. PATIENTS AND METHODS: •  Paraffin-embedded transurethral resection tissue from 113 patients with UC was investigated for the association of p85aPI3K, p-AKT, p-mTOR, p-p70S6K and p-4E-BP1 (eukaryotic initiation factor 4E-binding protein 1) expression status, as well as PIK3CA and AKT1 mutations with p-extracellular signal-regulated kinase 1/2 (ERK1/2), fibroblast growth factor receptor 3 (FGFR3), pathological features, recurrence and cancer-specific survival. RESULTS: •  With the exception of p-p70S6K, all others components of the PI3K/AKT/mTOR pathway were upregulated in UCs as compared with normal urothelium. •  p-mTOR expression strongly correlated with its upstream p-AKT and marginally with its downstream p-p70S6K. p85aPI3K and p-ERK1/2 levels were also marginally correlated. •  PIK3CA and AKT1 mutations were distinctly uncommon and mutually exclusive, without any association with pathological features. However, the presence of AKT1 mutations was associated with increased FGFR3 levels and was restricted to p85aPI3K immunonegative cases, whereas PIK3CA mutant cases had marginally lower p85aPI3K levels. •  The presence of PIK3CA single or combined with AKT1 mutations was associated with shorter recurrence-free survival in univariate survival analysis. An inverse relationship was established between p-4E-BP1 immunopositivity and histological grade or T category, as well as between p-p70S6K levels and T category, the latter relationship being of marginal significance. •  p-4E-BP1 nuclear expression was marginally associated with the presence of lymphovascular invasion and adversely affected survival in multivariate, but not in univariate analysis. CONCLUSIONS: •  PI3K/AKT/mTOR signalling components appear to be differentially implicated in urothelial tumorigenesis and, with the exception of p85aPI3K, are unrelated to the PIK3CA or AKT1 mutational status. •  Our findings propose p-4E-BP1 as a potential prognostic marker in UC independent of its association with pathological features, which might assist the selection of patients more likely to benefit from PI3K/AKT/mTOR axis inhibition. •  PIK3CA/AKT1 mutational status may have a place in the prediction of time-to-recurrence.
    BJU International 10/2012; · 3.05 Impact Factor
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    ABSTRACT: Glyoxalase detoxification system composed of glyoxalase-I and II (GLO-I, II), is ubiquitously expressed and implicated in the protection against cellular damage due to cytotoxic metabolites such as advanced glycation end-products (AGEs). Recently, ovarian tissue has emerged as a new target of excessive AGEs deposition been associated either with a high AGEs diet in experimental animals or hyperandrogenic disorders like Polycystic Ovarian Syndrome (PCOS) in humans. This study was designed to investigate the impact of dietary AGEs and androgens in rat ovarian GLO-I activity of normal non-androgenized (NAN, Group A, n=18) and androgenised prepubertal (AN) rats (Group B, n=29). Both groups were further randomly assigned, either to high (HA) or low (LA) AGE content diet for 3 months. The activity of ovarian GLO-I was significantly reduced in normal NAN animals fed with HA diet compared to LA (p=0.006). Furthermore, GLO-I activity was markedly reduced in AN animals compared to NAN (p≤0.001) when fed with the corresponding diet type. In addition, ovarian GLO-I activity was positively correlated with the body weight gain (r(s)=0.533, p<0.001), estradiol (r(s)=0.326, p=0.033) and progesterone levels (r(s)=0.500, p<0.001). A negative correlation was observed between GLO-I activity and AGEs expression in the ovarian granulosa cell layer of all groups with marginal statistical significance (r(s)=-0.263, p=0.07). The present data demonstrate that ovarian GLO-I activity may be regulated by dietary composition and androgen levels. Modification of ovarian GLO-I activity observed for the first time in this androgenised prepubertal rat model, may present a contributing factor to the reproductive dysfunction characterising PCOS.
    Molecular Medicine 07/2012; · 4.47 Impact Factor
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    ABSTRACT: To investigate the significance of the mammalian target of rapamycin (mTOR) pathway in astrocytic tumours, published information in this context being limited, especially regarding phosphorylated 4E-binding protein (p-4E-BP) 1. Paraffin-embedded tissue from 111 patients with astroglial tumours (grades II-IV) was investigated for the association of phosphorylated mTOR (p-mTOR) signalling components with phosphorylated extracellular signal-related kinase 1/2 (p-ERK1/2) and phosphorylated AKT (p-AKT) expression, clinicopathological features, angiogenesis, isocitrate dehydrogenase 1 (IDH1)-R132H, and survival. Expression was also quantified by western blot analysis in 12 cases and in three primary glioma cell cultures following rapamycin treatment. p-mTOR expression correlated with p-4E-BP1 expression and marginally with p-p70S6K expression. p-4E-BP1 expression increased with tumour grade. Rapamycin induced a decline in phosphorylation levels of all three proteins. Nuclear p-AKT and cytoplasmic p-ERK1/2 immunoexpression correlated with p-4E-BP1 expression, whereas cytoplasmic p-AKT expression correlated with p-p70S6K expression. All three proteins were associated with increased angiogenesis but not with IDH1-R132H expression status. p-mTOR adversely affected overall and disease-free survival in univariate analysis. In multivariate survival analysis, the presence of p-4E-BP1 predicted shortened overall survival in the entire cohort and glioblastomas. mTOR signalling components are differentially involved in the acquisition of a more aggressive and angiogenic phenotype in astrocytic tumours. Moreover, p-4E-BP1 emerges as a novel prognostic marker, which might aid in the selection of patients who are more likely to benefit from therapy with mTOR inhibitors.
    Histopathology 06/2012; 61(2):293-305. · 2.86 Impact Factor
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    ABSTRACT: Here, we summarise the results after carrying out a large survey regarding the assessment of vascular alterations, both vessel changes and vascular lesions in an inter-laboratory setting. In total, 32 neuropathologists from 22 centres, most being members of BrainNet Europe (BNE), participated by filling out a questionnaire with emphasis on assessment of common vascular alterations seen in the brains of aged subjects. A certain level of harmonisation has been reached among BNE members regarding sectioning of the brain, harvesting of brain tissue for histology and staining used when compared to the survey carried out in 2006 by Pantoni and colleagues. The most significant variability was seen regarding the assessment of severity and of clinical significance of vascular alterations. Two strategies have recently been recommended regarding the assessment of vascular alterations in aged and demented subjects. The National Institute on Aging - Alzheimer's Association (NIA-AA) recommends the assessment of hippocampal sclerosis, vascular brain injury and microvascular lesions in 12 regions. Although this strategy will be easy to follow, the recommendations do not inform how the load of observed alterations should be assessed and when the observed lesions are of significance. Deramecourt and his colleagues recommend an assessment and semiquantitative grading of various pathologies in 4 brain regions. This strategy yielded a total score of 0 to 20 as an estimate of pathology load. It is, however, not clear which score is considered to be of clinical significance. Furthermore, in several BNE trials the semiquantitative assessment has yielded poor agreement rates; an observation that might negatively influence the strategy proposed by Deramecourt and his colleagues. In line with NIA-AA, a dichotomised approach of easily recognisable lesions in a standardised set of brain regions harvested for neuropathological assessment and applying reproducible sampling and staining strategies is recommended by BNE. However, a simple strategy regarding assessment of load of alteration is urgently needed to yield reproducible, and at the same time, comparable results between centres.
    Experimental gerontology 06/2012; 47(11):825-33. · 3.34 Impact Factor
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    ABSTRACT: Replication protein A (RPA) is an ssDNA-binding protein required for the initiation of DNA replication and the stabilization of ssDNA. Collaboration with several molecules, that is, the MCM2-7 complex, has been suggested to be imperative for its multifaceted role. In this study, we investigated the immunohistochemical expression of the RPA2 subunit in correlation with the MCM-2 and MCM-5 and Ki67 index, and assessed its prognostic significance in 76 patients with nonearly ovarian adenocarcinomas, the majority of whom had a serous histotype. RPA2 protein expression was observed in all cases, whereas the staining intensity varied from weak to strong. RPA2 expression was correlated with the tumor stage in the entire cohort and in serous tumors (P=0.0053 in both relationships). Moreover, RPA2 immunoexpression was positively correlated with MCM-2 (P=0.0001) and MCM-5 (P<0.0001) expression, but was unrelated to the Ki67 index (P>0.10). In multivariate survival analysis, RPA2 expression emerged as an independent predictor of adverse outcome (P<0.0001) along with tumor histologic grade. RPA2 remained an independent predictor of survival (P=0.002) even after adjustment for MCM-2 and MCM-5 expression and when analysis was restricted to serous carcinomas (P=0.004). Our results further support the interrelation of RPA2 protein with MCM-2 and MCM-5 in OCs. Moreover, RPA2 protein may play an important role in ovarian tumorigenesis, and may serve as a useful independent molecular marker for stratifying patients with OC in terms of prognosis.
    International journal of gynecological pathology: official journal of the International Society of Gynecological Pathologists 05/2012; 31(4):319-27. · 2.07 Impact Factor

Publication Stats

1k Citations
316.34 Total Impact Points

Institutions

  • 2009–2014
    • Laiko Hospital
      Athínai, Attica, Greece
  • 2005–2014
    • Athens State University
      Athens, Alabama, United States
  • 2009–2013
    • University of Crete
      • • School of Medicine
      • • Department of Haematology
      Réthymnon, Kriti, Greece
  • 2002–2013
    • National and Kapodistrian University of Athens
      • • Division of Pathophysiology
      • • Faculty of Medicine
      • • Division of Hematology
      • • Department of Medicine
      Athínai, Attica, Greece
  • 2012
    • University of Eastern Finland
      Kuopio, Eastern Finland Province, Finland
    • Athens Medical Center
      Athínai, Attica, Greece
  • 2006–2009
    • University of Kuopio
      Kuopio, Eastern Finland Province, Finland
  • 1993
    • INRS
      Lutetia Parisorum, Île-de-France, France