Helen P. Kourea
University of Patras
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Helen P. Kourea.
American Journal of Pathology | 1999
Helen P. Kourea; Irene Orlow; Bernd W. Scheithauer; Carlos Cordon-Cardo; James M. Woodruff
The INK4A gene, a candidate tumor suppressor gene located on chromosome 9p21, encodes two protein products, p16 and p19(ARF). p16 is a negative cell cycle regulator capable of arresting cells in the G1 phase by inhibiting cyclin-dependent kinases 4 (Cdk4) and 6 (Cdk6), thus preventing pRB phosphorylation. p19(ARF) prevents Mdm2-mediated neutralization of p53. Loss of INK4A is a frequent molecular alteration involved in the genesis of several neoplasms, including tumors of neuroectodermal origin. This study investigated the frequency of INK4A gene alterations in a series of malignant peripheral nerve sheath tumors (MPNSTs) and neurofibromas (NFs). INK4A gene and the p19(ARF)-specific exon 1beta were studied in 11 MPNST samples from 8 patients and 7 neurofibromas. Presence of INK4A deletions was assessed by Southern blotting hybridization and by a multiplex polymerase chain reaction (mPCR). INK4A point mutations were examined by single-strand conformation polymorphism (SSCP) and sequencing. The p16 promoter methylation status was determined by PCR amplification of bisulfite-treated DNA. Homozygous deletions of exon 2, thus affecting both p16 and p19(ARF), were identified in MPNSTs from 4 of 8 patients. Deletions, mutations, or silencing by methylation were not identified in the neurofibromas analyzed. Based on our results, we conclude that INK4A deletions are frequent events in MPNSTs and may participate in tumor progression. Silencing of p16 by methylation, which occurs often in several tumor types, is uncommon in MPNSTs.
American Journal of Pathology | 1999
Helen P. Kourea; Carlos Cordon-Cardo; Maria E. Dudas; Denis H. Y. Leung; James M. Woodruff
There is little information regarding the status of cell cycle regulators in malignant peripheral nerve sheath tumors (MPNSTs) and neurofibromas (NFs). In this study, we investigated patterns of expression of p53 and pRB, cyclin-dependent kinase inhibitors (CKIs) p21 and p27, as well as cyclins D1 and E, in a cohort of 35 well-characterized MPNSTs and 16 NFs. These phenotypes were correlated with proliferative index, as assessed by Ki-67, as well as clinicopathological parameters of poor outcome. p53 nuclear overexpression was found in 10 of 35 (29%) MPNSTs, and it was lacking in NFs (P = 0.02). There were no differences in the patterns of expression of pRB, cyclin D1, and p21 between MPNSTs and NFs. However, p27 nuclear expression was present in most NFs, but it was absent in the majority of MPNSTs, which displayed cytoplasmic staining (P < 0.001). Nuclear cyclin E expression was more pronounced in MPNSTs than in NFs. We observed inverse patterns of expression for nuclear p27 and nuclear cyclin E expression. The staining profiles of cytoplasmic p27 and nuclear cyclin E expression were found to be statistically associated (P = 0.01). High Ki-67 expression was found in 20 of 34 (59%) MPNSTs but was absent in NFs (P < 0.001). Furthermore, detection of cytoplasmic p27 expression was found to be a prognostic factor for poor survival in MPNSTs (P = 0.03, relative risk = 2.4).
Lung Cancer | 2009
Ioannis P. Gialmanidis; Vasiliki Bravou; Stavroula G. Amanetopoulou; John Varakis; Helen P. Kourea; Helen Papadaki
The hedgehog (HH)-signaling pathway is implicated in developmental processes and its aberrant activation in adult tissues has been associated with malignancy. The aim of this study was to determine the expression pattern of HH-signaling molecules in non-small cell lung carcinomas (NSCLC), as well as the involvement of the transcription factor FOXM1, that controls cell proliferation, in this process. Paraffin-embedded tissue sections of 80 NSCLC cases and adjacent non-neoplastic lung parenchyma were immunohistochemically analyzed with anti-SHH, anti-Patched1 (PTCH1), anti-Smoothened (SMO), anti-GLI1, anti-GLI2 and anti-FOXM1 antibodies. Correlations of HH molecules with clinicopathological parameters and FOXM1 expression were evaluated. All the HH-signaling molecules examined were overexpressed in NSCLC compared with the adjacent non-neoplastic lung parenchyma. HH pathway activity and expression of PTCH1 and SMO were significantly higher in squamous cell carcinomas compared to other NSCLC histological types. Activation of HH pathway and PTCH1 expression were correlated with tumor grade being higher in low grade tumors. There was a significant correlation of lymph node metastases with expression of SMO in all NSCLC histological types and with nuclear GLI1 immunolocalization only in adenocarcinomas. Overexpression of FOXM1 in NSCLC was also significantly correlated with PTCH1, SMO and GLI1 expression. In conclusion, HH-signaling pathway is activated in NSCLC and correlates with histological type, prognostic parameters of the tumors as well as with the increased expression of FOXM1.
Obstetrics & Gynecology | 1995
Paul DiSilvestro; Walter Gajewski; Mark E. Ludwig; Helen P. Kourea; James Sung; C.O. Granai
Objective To review the experience at Women & Infants Hospital and Hartford Hospital of patients with malignant mixed mesodermal tumors of the ovary, and to review the pertinent literature. Methods Fourteen cases of malignant mixed mesodermal tumors of the ovary at the two hospitals over a 5-year period were identified through their tumor registries. Demographic data, pathology, treatment, and survival rates were reviewed. Results The median survival of the patients in our series was 7 months, with 64% dead of disease in 1 year. A review of the pertinent literature indicated median survivals of 6–12 months, with more than 70% of the patients dead of disease at 1 year, despite treatment. Conclusion Further investigation is needed to determine the proper management for malignant mixed mesodermal tumors of the ovary. Meanwhile, current treatment strategies should recognize the present therapeutic limitations, so as not to diminish any further the quality of life for women with this malignancy.
Breast Cancer Research and Treatment | 2005
George Fountzilas; Dimitrios Pectasides; Anna Kalogera-Fountzila; Dimosthenis Skarlos; Haralabos P. Kalofonos; Christos Papadimitriou; Dimitrios Bafaloukos; Stefanos Lambropoulos; Savvas Papadopoulos; Helen P. Kourea; Christos Markopoulos; Helen Linardou; D. Mavroudis; Evangelos Briasoulis; Nicholaos Pavlidis; Evangelia Razis; Paraskevas Kosmidis; Helen Gogas
SummaryPaclitaxel (TaxolR) and carboplatin are an effective combination regimen for treating advanced breast cancer. Gefitinib (IRESSA) is the first epidermal growth factor receptor tyrosine kinase inhibitor to be approved for cancer treatment. This multicenter phase II trial treated 68 patients with advanced breast cancer with paclitaxel (175 mg/m2 over 3 h) and 3-weekly carboplatin (area under the curve of 6) for six cycles, and 250 mg/day gefitinib orally. Median age was 57 (range 35–77) years, patients had performance status 0 (69.1%), 1 (27.9%) 2 (2.9%), 82.4% of patients had visceral metastases and 63.2% had received adjuvant chemotherapy. Forty-eight (70.6%) patients completed six cycles of chemotherapy and 20 (29.4%) patients discontinued treatment (seven [10.3%] due to disease progression, seven [10.3%] due to toxicity, five [7.4%] withdrew consent and one [1.5%] died after the first cycle). Sixty-three (92.7%) patients were evaluable for response; nine (13.2%) had complete responses, 30 (44.1%) had partial responses, 21 (30.9%) had stable disease and three (4.4%) had disease progression. Grade 3/4 adverse events in ≥5% of patients except of alopecia, included neutropenia (17.7%), anemia (10.3%), diarrhea (7.4%), thrombocytopenia (5.9%) and peripheral neuropathy (5.9%). Of those tumor biopsies available for immunohistochemical analysis (n=60), 5.0% were positive and 35.0% negative for expression of all HER-family receptors. Comparable numbers of tumor biopsies were nuclear p27kipl positive and negative (39.7 and 42.7%, respectively), with the majority (72.1%) negative for cytoplasmic p27kipl. The observed efficacy data in this study were similar to those reported for the combination of paclitaxel and carboplatin alone.
Oncotarget | 2016
Vassiliki Kotoula; Kyriakos Chatzopoulos; Sotiris Lakis; Zoi Alexopoulou; Eleni Timotheadou; Flora Zagouri; George Pentheroudakis; Helen Gogas; Eleni Galani; Ioannis Efstratiou; Thomas Zaramboukas; Angelos Koutras; Gerasimos Aravantinos; E. Samantas; Amanda Psyrri; Helen P. Kourea; Mattheos Bobos; Pavlos Papakostas; P. Kosmidis; Dimitrios Pectasides; George Fountzilas
Background Tumor infiltrating lymphocytes (TILs) are considered in the prognosis of breast cancer (BC) patients. Here, we investigated the prognostic/predictive effect of TILs in patients treated in the frame of four prospective trials with adjuvant anthracycline-based chemotherapy in the pre- and post-trastuzumab era. Methods TILs density was histologically assessed as percentage of stromal area on whole routine sections of 2613 BC (1563 Luminal A/B; 477 Luminal HER2; 246 HER2-enriched; 327 triple negative [TNBC]) and were evaluated as high/low at three cut-offs (c/o; 50% [lymphocytic predominance, LP], 35% and 25%), in separate training and validation sets. Results High TILs were present in 3.5%, 6.5% and 11.5% of all tumors, using the 50%, 35% and 25% c/o, respectively. TILs status did not interact with BC subtypes or trastuzumab treatment. LPBC patient outcome was not affected by nodal status, while high TILs were favorable in TNBC with unfavorable nodal status. When adjusted for standard clinicopathological parameters and treatment, high TILs independently predicted for favorable outcome, e.g., disease-free survival with the 35% c/o in the entire cohort (HR = 0.44, 95% CI 0.28-0.69, p < 0.001) and in specific subtypes. Conclusions High TILs tumors, especially LPBC seem worthy validating as a separate entity of favorable prognosis in breast cancer.
Journal of Clinical Pathology-molecular Pathology | 2003
Helen P. Kourea; Angelos Koutras; C D Scopa; M N Marangos; E Tzoracoeleftherakis; D Koukouras; Haralabos P. Kalofonos
Aims: To look for correlations between expression of cell cycle regulatory proteins p34cdc2, p21WAF1, and p53 in node negative invasive ductal breast carcinoma, or between these proteins and clinicopathological parameters, and to assess their prognostic value. Methods: Immunohistochemistry using formalin fixed, paraffin wax embedded sections from 94 breast carcinomas. Adjacent benign epithelial breast tissue was available in 74 cases. Median follow up was 72 months. Results: Nuclear and cytoplasmic p34cdc2 expression was seen in 80 and 62 tumours, respectively; nuclear expression was seen in adjacent benign epithelium in 12 cases. p21WAF1 and p53 were positive in 48 and 21 tumours, respectively. High expression of p34cdc2 in neoplastic nuclei was associated with higher histological grade and p53 expression, but not with tumour size, steroid receptor status, patient age, menopausal status, recurrence, metastasis, disease free survival (DFS), or overall survival (OS). p34cdc2 in tumour cytoplasm was associated with p34cdc2 nuclear positivity, high tumour grade, and DFS in univariate but not multivariate analysis. In contrast, p34cdc2 expression in benign tissue independently predicted DFS and OS in univariate and multivariate analysis. Expression of p53 was associated with high tumour grade and negative steroid receptors, but not with recurrence, metastasis, DFS, or OS. p21WAF1 expression was not associated with the examined parameters. Conclusions: p34cdc2, p21WAF1, and p53 expression does not predict outcome in node negative breast carcinoma, although p34cdc2 expression in benign tissue is related to prognosis. The association between p34cdc2 and p53 implicates p53 in G2–M cell cycle checkpoint control, possibly via mediators unrelated to p21WAF1.
Journal of Obstetrics and Gynaecology Research | 2013
Marinos Nikolaou; Helen P. Kourea; Kostas Antonopoulos; Katerina Geronatsiou; George Adonakis; George Decavalas
We report a rare case of spontaneous uterine rupture of an unscarred uterus caused by adenomyosis in the early third trimester. A 33‐year‐old primigravid woman was referred to our department because of severe acute abdominal pain and signs and symptoms of hemorrhagic shock. Ultrasound exanimation performed at admission revealed a living, intrauterine fetus of 28 weeks gestational age with reduced amniotic fluid and presence of free peritoneal fluid. The fetal heart rate was non‐reassuring with variable decelerations and severe fetal bradycardia. Emergency cesarean section revealed massive hemoperitoneum and complete rupture in the uterine fundus. Subtotal peripartum hysterectomy with conservation of adnexae was performed. Histological examination revealed adenomyosis at the site of uterine rupture.
European Journal of Obstetrics & Gynecology and Reproductive Biology | 2009
Vassilis G. Papadopoulos; Helen P. Kourea; George Adonakis; George Decavalas
Hemangiomas of the umbilical cord are extremely rare benign vascular tumors, not always detected prenatally. They have been associated with increased alpha-fetoprotein (AFP), hydramnios, congenital anomalies, and increased perinatal mortality. Impaired umbilical circulation has been proposed as the predisposing factor for fetal compromise. We report a case of an antenatally detected umbilical cord hemangioma with one artery crossing the tumor, and we reviewed the literature. Close surveillance with Doppler flow studies of the umbilical vessels were carried out throughout the pregnancy. All indices were normal, except from the intra-tumoral part of the umbilical artery under discussion that showed increasing resistance from 32 weeks onwards. Our review confirmed the reported association with increased AFP and hydramnios. The placental end of the cord was the preferred site of location, and the umbilical artery the commonest vessel of origin. Association with cutaneous vascular malformations, and single umbilical artery were assessed.
Current Molecular Pharmacology | 2015
Helen P. Kourea; Vassiliki Zolota; Chrisoula D. Scopa
Breast carcinoma is currently considered as a group of diseases, differing not only in histopathologic phenotype, as indicated by histologic type and grade, but also in their protein, genetic and epigenetic molecular profile. The standard of care indicates that the core information for patient management includes data on Estrogen Receptor (ER), Progesterone Receptor (PgR) and Human Epidermal Growth Factor Receptor 2 (HER2), while there is an emerging role for the proliferation marker Ki67. These indices can be provided even in low resource settings and are indispensable for prognostication and therapeutic patient management. With the progress in molecular and translational research, there is a growing body of information on the molecular subtypes of breast carcinoma and their significance, and multigene signature assays are used to dictate prognosis and guide therapeutics in high resource settings. In addition, several cellular pathways involved in tumor growth and spread are dissected and targeted in clinical trials. Among these are the p53, RB, PI3K/Akt/mTOR and Ras/MAPK pathways, alterations associated with genetic instability and epigenetic alterations including histone methylation and acetylation, DNA methylation and microRNAs expression. The tumor immune microenvironment, including the tumor infiltrating lymphocytes (TILs) is attracting significant research interest. This review summarizes the mechanisms of function of the above factors in breast tumorigenesis with emphasis on their prognostic and predictive value and their use as therapeutic targets.