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Previous studies showed that peripheral blood lymphocytes of B-cell chronic lymphocytic leukemia (B-CLL) displayed a high intracellular level of cell cycle inhibitory protein p27(Kip1). It has been suggested that its' high expression may confer them survival advantage and lead to unfavorable prognosis, but the prognostic significance of p27(Kip1) expression for previously untreated, non-advanced stage B-CLL was not established. We studied a relationship between the intracellular level of p27(Kip1) of lymphocytes of early- and intermediate stage B-CLL patients and their spontaneous apoptosis in vitro, as well as prognostic significance of p27(Kip1) in B-CLL lymphocytes for the risk of disease progression. Intracellular p27(Kip1) content of peripheral blood lymphocytes obtained from 48 previously untreated 0-II Rai stage B-CLL patients was determined by flow cytometry. The viability and apoptosis of those lymphocytes after 72-h culture were also assessed. During the follow-up period (6-71 months, median 59.5), we recorded the time elapsed to the doubling of lymphocyte count, progression to a higher Rai stage and the appearance of indications for cytostatic treatment. The p27(Kip1) expression was neither correlated with initial lymphocyte count, CD38 expression, cell viability nor spontaneous apoptosis ratio after 72-h culture. Higher p27(Kip1) level was related to the probability of earlier occurrence of each of three above-mentioned events. We did not find a prognostic significance of in vitro cell viability nor apoptosis as to the risk of disease progression. Our results indicate that elevated intracellular p27(Kip1) level in leukemic lymphocytes of early- and intermediate stage B-CLL patients contributes to rapid progression of the disease.

Eph receptors represent the largest subfamily of receptor tyrosine kinases (RTKs). The up- regulation of Eph receptors has been documented in various solid tumors, where it often correlates with poor prognosis. Their significance in hematologic malignancies is still unclear. This study aimed to investigate the expression of Eph A4, Eph B2, and Eph B4 mRNA in non - M3 AML patients and determine their prognostic significance. Bone marrow samples from 101 newly diagnosed non - M3 AML patients and 26 healthy controls for comparison were quantified by real time reverse transcriptase polymerase chain reaction (RT-PCR), and the comparative cycle threshold (Ct) method was used to determine their relative expression levels to GUS control gene. The results showed that expression of all selected Eph receptors was significantly lower in AML patients comparing to controls. It also differed according to FAB subtypes. The decreased expression levels of Eph A4 were associated with higher leukocytes (p = 0.022) and blast cell counts (p = 0.001), and unfavorable FLT3-ITD mutation. Our study revealed significant correlation between lower EphB2 expression levels, and higher complete remission rate (p = 0.009724) and longer overall survival. Additionally, we found that patients with shorter RFS had decreased EphB4 expression (p = 0.00). In conclusion, the results suggest the prognostic impact of decreased expression levels of some Eph receptors in AML patients.

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The most recent studies emphasize a link between B-cell proliferation in vivo and clinical outcome of B-cell chronic lymphocytic leukemia (B-CLL). The expression of cyclin D2 in B-CLL cells isolated from the peripheral blood of 27 untreated patients in relation to the apoptosis ratio both before and 72 h after culture in the absence of growth factors was analyzed by immunocytochemistry. The significant associations between cell death in culture and both cyclin D2 expression in freshly isolated cells and the rate of its decrement in culture found in this study confirm the special role of cyclin D2 in enhancing the longevity of these cells in vivo. As cyclin D2 is inducible in the early G1 phase, its increased expression might also reflect the activation of cells attempting to replicate in vivo. Furthermore, the finding that B-CLL progression positively correlates with the gradual increase in the proportion of apoptotic B lymphocytes in culture seems to support the notion of cells striving to undergo division in the absence of growth factors. All together, these results indicate the possibility that cyclin D2+ cells represent a pool of leukemic cells with the potential to enter the dividing compartment.