Supervisors info:
Παναγούλα Κόλλια, Καθηγήτρια Μοριακής Γενετικής Ανθρώπου, Τμήμα Βιολογίας, ΕΚΠΑ
Summary:
Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal disorders of the multipotent hematopoietic cell characterized by disorders of its maturation and differentiation and inefficient hematopoiesis. MDS occurs in the elderly (<70 years) and is a chronic disease with a high risk of diversion to Acute Myelogenous Leukemia and a life expectancy of 0.5 to 6 years. According to a possible pathogenic disease model for the onset and diversion to Acute Myelogenous Leukemia is required the accumulation of a significant number of mutations. There must be a state of genetic instability in the cells, which is also caused by the malfunction of one or some mechanisms of repair of the genetic material. In this thesis we investigate the expression of a large number of genes (PCR arrays) involved in different genetic repair mechanisms (BER, NER, HR, NHEJ, MMR or others) to identify differences in their expression between patients and healthy controls. Then, based on the results of the arrays, three genes were selected (XAB2, RPA1, ERCC8) which are evaluated for their expression with quantitative pcr. The methodology used is Real-Time PCR, which calculates the difference in the expression of these genes between a group of patients (21 patients) and the control group (21 healthy individuals of similar age). Patients belong to seven categories of MDS (RAEB1, RAEB2, RA, RARS, RA, RCMD and Del5q) as defined by the World Health Organization in 2008. The tissue examined is mostly isolated peripheral blood monocytes except for a sample derived from the bone marrow. The relative expression of the repair genes is calculated by the ΔΔCT method and is examined first among all the pathological samples in relation to the control group and then between high / low MDS malignancy.
The results of the aforementioned methodology show that in patients with MDS the two repair genes (XAB2, ERCC8) are downregulated, which indicates a large accumulation of defects in the genetic material. The RPA1 gene appears to be upregulated, which justifies the gradual progression of the disease to malignancy. Therefore, the experimental results of the present work contribute to the understanding of the role of the numerous molecules involved in the different repair mechanisms and their relationship to the different MDS categories and the control group. In this way, an attempt is made to interpret the observed changes in the expression of the genes under study and correlation with the pathogenesis mechanisms of MDS, in order to properly evaluate and contribute to the investigation of predisposition, early diagnosis and / or treatment of patients with MDS.
Keywords:
DNA repair mechanisms, Myelodysplastic Syndromes, NER repair mechanism, gene expression
