Flowcytometric evaluation of cell cycle regulators (cyclins and cyclin dependent kinase inhibitors) expressed on bone marrow cells of patients with chronic myelogenous leukemia and multiple myeloma

OBJECTIVE: Etiopathology of malignancy can be demonstrated by the comparison of the quantified changes in the different phases of the cycle about cyclins and cyclin dependent kinase inhibitors (CDKI) in healthy and malignant proliferated cells. The aim of this study is to analyze flow cytometric expression of cell cycle regulating elements in the malignant diseases with low and high proliferative signature.\ud METHODS: The levels of cyclin D, E, A, B and CDKI's p16, p21 were studied by flowcytometry in patients with chronic myeloid leukemia (CML) (n=16), multiple myeloma (MM) (n=13) and control subjects (n=15). \ud RESULTS: The distributions of the cell cycle S phase were 10, 63%, 6, 72% and 3, 59%; for CML, MM and control subjects, respectively. Among all the cyclins expressed during the S phase, cyclin D expression was the lowest, in CML patients. While the distribution of cyclins and CDKI’s was similar between MM and control groups in G2/M phase; cyclins expressions were parallel in all three phases in MM and chronic myeloid leukemia groups.\ud CONCLUSION: CML and MM are diseases presenting with variable degrees of proliferation. The increase of cyclins in cell cycle phases in patient group was not associated with the augmentation of the expression of CDKI’s. This finding may contribute the mechanisms effective in the etiopathogenesis of hematological malignancy