الفهرس 
ACUTE LEUKEMIAOnly 14 pages are availabe for public view
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Abstract
Cancer stem cells are a small subset of cancer cells constituting a reservoir of self-sustaining cells with the exclusive ability to self-renew and maintenance of the tumor. These cells are identified by specific stem cell markers: antigens, molecules and signaling pathways. CD133 represents a marker of cancer stem cells in a number of human cancers like human leukemia and therefore, it may be possible to develop future therapies targeting these cells via clearer under-standing of the molecular mechanisms of CD133-expressing cells.
Prominin-1/CD133 is pentaspan transmembrane glycoprotein. The interest in this molecule has grown exponentially, since it appears to be an important cell surface marker widely used to identify and isolate stem cells from various sources, including the hematopoietic and central nervous systems, as it does not share homology with other hemopoietic stem cell (HSC) surface antigens. It is rapidly down-regulated as human HSCs differentiate into phenotypically restricted cells and this rapid down-regulation during cell differentiation is a characteristic feature of this protein, which makes it a unique cell surface marker for the identification and isolation of stem cells and progenitor cells.
Detection of CD133 expression at diagnosis is of high clinical relevance, because its expression has a direct consequence for treatment stratification, being associated with poor prognosis.
The aim of the present study was to determine the expression of CD133 molecule on the surface of myeloid and lymphoid blasts from patients with acute leukemia in a trial to correlate the expression of this molecule to various clinical and laboratory data determining its diagnostic value for acute leukemia immunophenotyping, as well as its relation to treatment response.
The current study was carried out on 30 newly diagnosed acute leukemia patients. All patients were subjected to complete history taking, thorough clinical examination and laboratory investigations including: complete hemogram, bone marrow aspiration with examination of Leishman-stained peripheral blood and bone marrow smears, immunophenotyping and flow cytometry analysis of CD133 expression using clone AC141 MoAb on the leukemic blast cell.
CD133 expression was not associated with any of the studied demographic, clinical or laboratory variables. The expression of CD133 had no relationship with the clinical prognostic factors such as sex, age, the percentage of leukemic cells in peripheral blood and in bone marrow, WBC counts, hemoglobin concentration and platelet counts.
On analyzing the association between CD133 expression and the immunophenotyping of acute leukemia, no significant association existed between CD133 positive expression and other cell surface markers, also there was no significant difference in CD133 expression between AML and ALL cell samples.
The results of this work showed a significant positive association between patients who did not respond to chemotherapy and positive CD133 expression. So, CD133 could be regarded as an independent risk factor for the prediction of poor response to chemotherapy.