Aggeliki Kolialexi
National and Kapodistrian University of Athens
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Featured researches published by Aggeliki Kolialexi.
Hormone Research in Paediatrics | 2004
Christina Kanaka-Gantenbein; Sophia Kitsiou; Ariadni Mavrou; Lela Stamoyannou; Aggeliki Kolialexi; Kyriaki Kekou; Magda Liakopoulou; George P. Chrousos
Aims: To describe the tall stature and its possible underlying mechanism in a Caucasian girl (age 12 years and 10 months) with 46,XX (28%)/47,XXX (72%) mosaicism and to identify the parental origin of her extra X chromosome. Methods: The fasting glucose-to-insulin ratio was studied. The karyotypes of the girl and her parents as well as the presence of SHOX copies and the parental origin of her extra X chromosome were assessed. Results: Clinical examination revealed a tall stature and severe acne, and endocrinological/metabolic assessment revealed insulin resistance. Fluorescence in situ hybridization cytogenetic analysis depicted the presence of three SHOX genes in the 47,XXX cell line of the patient. Karyotyping of her parents showed a normal 46,XX karyotype in the mother and 46,XY(93%)/47,XXY(7%) Klinefelter mosaicism in the father. However, DNA analysis unequivocally showed maternal origin of the extra X chromosome of the patient. Conclusions: This report suggests that SHOX gene triplication may produce a tall stature, even in the presence of preserved ovarian function. X triplication might predispose to insulin resistance and behavioral disorders.
Journal of Hematology & Oncology | 2014
Maria Braoudaki; George I. Lambrou; Krinio Giannikou; Vasilis Milionis; Kalliopi Stefanaki; Diane K. Birks; Neophytos Prodromou; Aggeliki Kolialexi; Antonis Kattamis; Chara Spiliopoulou; Fotini Tzortzatou-Stathopoulou; Emmanouel Kanavakis
BackgroundAlthough, substantial experimental evidence related to diagnosis and treatment of pediatric central nervous system (CNS) neoplasms have been demonstrated, the understanding of the etiology and pathogenesis of the disease remains scarce. Recent microRNA (miRNA)-based research reveals the involvement of miRNAs in various aspects of CNS development and proposes that they might compose key molecules underlying oncogenesis. The current study evaluated miRNA differential expression detected between pediatric embryonal brain tumors and normal controls to characterize candidate biomarkers related to diagnosis, prognosis and therapy.MethodsOverall, 19 embryonal brain tumors; 15 Medulloblastomas (MBs) and 4 Atypical Teratoid/Rabdoid Tumors (AT/RTs) were studied. As controls, 13 samples were used; The First-Choice Human Brain Reference RNA and 12 samples from deceased children who underwent autopsy and were not present with any brain malignancy. RNA extraction was carried out using the Trizol method, whilst miRNA extraction was performed with the mirVANA miRNA isolation kit. The experimental approach included miRNA microarrays covering 1211 miRNAs. Quantitative Real-Time Polymerase Chain Reaction was performed to validate the expression profiles of miR-34a and miR-601 in all 32 samples initially screened with miRNA microarrays and in an additional independent cohort of 30 patients (21MBs and 9 AT/RTs). Moreover, meta-analyses was performed in total 27 embryonal tumor samples; 19 MBs, 8 ATRTs and 121 control samples. Twelve germinomas were also used as an independent validation cohort. All deregulated miRNAs were correlated to patients’ clinical characteristics and pathological measures.ResultsIn several cases, there was a positive correlation between individual miRNA expression levels and laboratory or clinical characteristics. Based on that, miR-601 could serve as a putative tumor suppressor gene, whilst miR-34a as an oncogene. In general, miR-34a demonstrated oncogenic roles in all pediatric embryonal CNS neoplasms studied.ConclusionsDeeper understanding of the aberrant miRNA expression in pediatric embryonal brain tumors might aid in the development of tumor-specific miRNA signatures, which could potentially afford promising biomarkers related to diagnosis, prognosis and patient targeted therapy.
Expert Review of Proteomics | 2011
Aggeliki Kolialexi; Georgia Tounta; Ariadni Mavrou; George Th. Tsangaris
Advances in technologies associated with mass spectrometry-based proteomic techniques have added a new dimension to the field of biomedical research. Most of the existing research on human gestation has focused on the application of these high-throughput methodologies in the study of amniotic fluid. In cases of fetal aneuploidies, the use of proteomic platforms has contributed to the identification of relevant protein biomarkers that could potentially change early diagnosis and treatment. The current article focuses on studies of normal amniotic fluid using proteomic technologies and describes alterations noted in the amniotic fluid proteome in the presence of fetal aneuploidies.
Tumor Biology | 2016
M. Braoudaki; George I. Lambrou; Krinio Giannikou; S. A. Papadodima; A. Lykoudi; Kalliopi Stefanaki; G. Sfakianos; Aggeliki Kolialexi; Fotini Tzortzatou-Stathopoulou; Maria Tzetis; Sophia Kitsiou-Tzeli; Emmanuel Kanavakis
In the current setting, we attempted to verify and validate miRNA candidates relevant to pediatric primary brain tumor progression and outcome, in order to provide data regarding the identification of novel prognostic biomarkers. Overall, 26 resected brain tumors were studied from children diagnosed with pilocytic astrocytomas (PAs) (n = 19) and ependymomas (EPs) (n = 7). As controls, deceased children who underwent autopsy and were not present with any brain malignancy were used. The experimental approach included microarrays covering 1211 miRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to validate the expression profiles of miR-15a and miR-24-1. The multiparameter analyses were performed with MATLAB. Matching differentially expressed miRNAs were detected in both PAs and EPs, following distinct comparisons with the control cohort; however, in several cases, they exhibited tissue-specific expression profiles. On correlations between miRNA expression and EP progression or outcome, miR-15a and miR-24-1 were found upregulated in EP relapsed and EP deceased cases when compared to EP clinical remission cases and EP survivors, respectively. Taken together, following several distinct associations between miRNA expression and diverse clinical parameters, the current study repeatedly highlighted miR-15a and miR-24-1 as candidate oncogenic molecules associated with inferior prognosis in children diagnosed with ependymoma.
Hormone Research in Paediatrics | 2007
Ch. Kanaka-Gantenbein; E. Papandreou; K. Stefanaki; Helen Fryssira; Aggeliki Kolialexi; C. Sophocleous; Ariadni Mavrou; Sophia Kitsiou-Tzeli; G. P. Chrousos
Background: Most true hermaphrodite patients – characterized by the presence of both ovarian and testicular tis- sue – demonstrate ambiguous genitalia and are diagnosed at birth, most commonly bearing a 46,XX karyotype. Patient and Methods: We report on a 13-year-old boy presenting with left scrotal hemorrhage. He had a left inguinal hernia, a palpable testis in the right, normal male external genitalia and significant gynecomastia. During operation, the left gonad and adjacent tissue were removed for histological examination, which revealed the presence of a normal ovary, rich in follicles and a ruptured corpus luteum, suggestive of spontaneous ovulation, with a normal ipsilateral adnexa and semi-uterus. Biopsy of the right gonad revealed a dysgenetic testicle. Endocrinological assessment postoperatively depicted high FSH, pubertal testosterone and low estradiol levels. Cytogenetic analysis in peripheral blood lymphocytes and FISH of the right gonad revealed a 46,XX (70–60%)/47,XXY (30–40%) karyotype, respectively, while molecular analysis verified the presence of SRY and azoospermia factor genes. Conclusion: The importance of full histological, cytogenetic and molecular investigation and of interdisciplinary approach in every single patient with sex differentiation disorders is highlighted by this rare case of spontaneous ovulation in a true hermaphrodite with normal male external genitalia and Klinefelter mosaicism.
Disease Markers | 2015
Aggeliki Kolialexi; Dimitrios Gourgiotis; George Daskalakis; Antonis Marmarinos; Alexandra Lykoudi; Danai Mavreli; Ariadni Mavrou; Nikolas Papantoniou
Aim. To examine the potential value of previously identified biomarkers using proteomics in early screening for preeclampsia (PE). Methods. 24 blood samples from women who subsequently developed PE and 48 from uncomplicated pregnancies were obtained at 11–13 weeks and analysed after delivery. Cystatin-C, sVCAM-1, and Pappalysin-1 were quantified by ELISA. Maternal characteristics and medical history were recorded. Results. Median values of Cystatin-C, sVCAM-1, and Pappalysin-1 in the PE group as compared to controls were 909.1 gEq/mL versus 480.0 gEq/mL, P = .000, 832.0 gEq/mL versus 738.8 gEq/mL, P = .024, and 234.4 gEq/mL versus 74.9 gEq/mL, P = .064, respectively. Areas under the receiver-operating characteristic curves (AUC, standard error (SE)) for predicting PE were Cystatin-C: 0.90 (SE 0.04), VCAM-1: 0.66 (SE 0.074), and Pappalysin-1: 0.63 (SE 0.083). To discriminate between cases at risk for PE and normal controls, cut-off values of 546.8 gEq/mL for Cystatin-C, 1059.5 gEq/mL for sVCAM-1, and 220.8 gEq/mL for Pappalysin-1 were chosen, providing sensitivity of 91%, 41%, and 54% and specificity of 85%, 100%, and 95%, respectively. Conclusions. sVCAM-1 and Pappalysin-1 do not improve early screening for PE. Cystatin-C, however, seems to be associated with subsequent PE development, but larger studies are necessary to validate these findings.
Experimental Dermatology | 2014
Evangelia Papadavid; Penelope Korkolopoulou; Georgia Levidou; Angelica A. Saetta; Theodora Papadaki; Marina P. Siakantaris; Vassiliki Nikolaou; Afroditi Oikonomidi; Ilenia Chatziandreou; Leonidas Marinos; Aggeliki Kolialexi; A. Stratigos; Dimitrios Rigopoulos; Amanta Psyrri; Eftratios Patsouris; Christina Antoniou
Deregulated signalling through phosphatidylinositol 3‐kinase (PI3K) pathway plays a critical role in tumour initiation and progression. We have already shown that AKT is activated in skin lesions in Mycosis Fungoides (MF) and we herein further investigate the frequency and clinical significance of PTEN and PI3K at the protein and at the DNA level as well as the presence of AKT1 mutations in skin lesions from 50 patients with MF clinical stages I‐IV in relation to clinicopathological features. Increased p‐AKT expression correlated with poor prognosis in plaques (P = 0.0198), whereas p‐AKT was an independent predictor of poor survival in the entire cohort (P = 0.017, HR = 1.012). PTEN cytoplasmic expression was found low or absent in all 77.3% of cases and inversely correlated with advanced clinical stages (P = 0.0744). Molecular analysis showed no AKT1 mutation, no PI3KCA copy number gain, only 1 case with PI3KCA mutation in exon 9 and 3 cases with PTEN mutations (7%) in exons 7, 8 and 5. The latter correlated with disease (P = 0.0253) and progression (P < 0.0001) free survival in tumour stage. Although activation of PI3K/AKT signalling pathway due to PTEN alterations is rarely attributed to abnormalities in PTEN, PI3K, and AKT1 genes, PTEN mutations exert a negative effect on patients’ prognosis with tumours.
Cancer Genetics and Cytogenetics | 2000
Salem Akel; Aggeliki Kolialexi; Ariadni Mavrou; Catherine Metaxotou; Dimitris Loukopoulos; Xenophon Yataganas
In chronic myeloid leukemia, accurate determination of Ph(-) Hemopoietic stem cells (HSC) in peripheral blood (PB), bone marrow (BM) and leukapheresis products is important for the selection of patients for whom mobilization, collection, and autografting of Ph(-) HSC are envisaged. To this effect, the BCR/ABL fusion was assessed at the single cell level in 25 sets of PB and BM samples using dual-color I-FISH in immunophenotyped CD34(+) cells and RT-PCR of individual CFU-GM colonies. In 15 cases found to be 100% Ph(+), the respective BCR/ABL gene was absent in 30% of CD34(+) cells, while the respective transcripts could not be identified in 17% of CFU-GM. The mean percentage of BCR/ABL(-) CD34(+) cells and CFU-GM cells was higher (38% and 29%, respectively) in untreated patients than in treated patients (24% and 7%, respectively). In eight cases with cytogenetic response (CgR), the percentage of Ph(-) metaphases correlated with the level of BCR/ABL(-) colonies in BM and PB and with the proportion of BCR/ABL(-) CD34(+) cells in the BM. Immunophenotyping and FISH was fast, easy, always informative, and quantitative for the BCR/ABL(-) CD34(+) cells. Our results show that (a) at early diagnosis a high frequency of BCR/ABL(-) HSC circulate in the PB and that Ph(-) hematopoiesis is not completely suppressed; (b) although normal clonogenic cells decline rapidly within a few months after diagnosis, appreciable numbers of normal CD34(+) cells survive in chronic phase, especially in patients with CgR.
Placenta | 2018
Alexandra Lykoudi; Aggeliki Kolialexi; George I. Lambrou; Maria Braoudaki; Charalampos Siristatidis; George Konstantinos Papaioanou; Maria Tzetis; Ariadni Mavrou; Nikolas Papantoniou
INTRODUCTION To determine the miRNA expression profile in placentas complicated by Preeclampsia (PE) and compare it to uncomplicated pregnancies. METHODS Sixteen placentas from women with PE, [11 with early onset PE (EOPE) and 5 with late onset PE (LOPE)], as well as 8 placentas from uncomplicated pregnancies were analyzed using miRNA microarrays. For statistical analyses the MATLAB® simulation environment was applied. The over-expression of miR-518a-5p was verified using Quantitative Real-Time Polymerase Chain Reaction. RESULTS Forty four miRNAs were found dysregulated in PE complicated placentas. Statistical analysis revealed that miR-431, miR-518a-5p and miR-124* were over-expressed in EOPE complicated placentas as compared to controls, whereas miR-544 and miR-3942 were down-regulated in EOPE. When comparing the miRNA expression profile in cases with PE and PE-growth restricted fetuses (FGR), miR-431 and miR-518a-5p were found over-expressed in pregnancies complicated by FGR. DISCUSSION Since specific miRNAs can differentiate EOPE and LOPE from uncomplicated placentas, they may be considered as putative PE-specific biomarkers. MiR-518a-5p emerged as a potential diagnostic indicator for EOPE cases as well as for PE-FGR complicated placentas, indicating a potential link to the severity of the disease.
Birth Defects Research Part A-clinical and Molecular Teratology | 2012
Maria Tzetis; Kalliopi Stefanaki; Areti Syrmou; Konstantina Kosma; Eleni Leze; Krinio Giannikou; Vasilis Oikonomakis; Christalena Sofocleous; Michael Choulakis; Aggeliki Kolialexi; Periklis Makrythanasis; Sophia Kitsiou-Tzeli
BACKGROUND Cat-Eye syndrome (CES) with teratoma has not been previously reported. We present the clinical and molecular findings of a 9-month-old girl with features of CES and also a palpable midline neck mass proved to be an extragonadal mature teratoma, additionally characterized by array comparative genomic hybridization (aCGH). RESULTS High resolution oligonucleotide-based aCGH confirmed that the supernumerary marker chromosome (SMC) derived from chromosome 22, as was indicated by molecular cytogenetic analysis with fluorescence in situ hybridization (FISH). Additionally, aCGH clarified the size, breakpoints, and gene content of the duplication (dup 22q11.1q11.21; size:1.6 Mb; breakpoints: 15,438,946-17,041,773; hg18). The teratoma tissue was also tested with aCGH, in which the CES duplication was not found, but the analysis revealed three aberrations: del Xp22.3 (108,864-2788,689; 2.7 Mb hg18), dup Yp11.2 (6688,491-7340,982; 0.65 Mb, hg18), and dup Yq11.2q11.23 (12,570,853-27,177,133; 14.61 Mb, hg18). These results indicated 46 XY (male) karyotype of the teratoma tissue, making this the second report of mature extragonadal teratoma in a female neonate, probably deriving from an included dizygotic twin of opposite sex (fetus in fetu). CONCLUSIONS Our findings extend the phenotypic spectrum of CES syndrome, a disorder with clinical variability, pointing out specific dosage-sensitive genes that might contribute to specific phenotypic features.
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Fotini Tzortzatou-Stathopoulou
National and Kapodistrian University of Athens
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