ABSTRACT
OBJECTIVE: To compare the efficiency of 3 different processing methods (Sepax, AutoXpress [AXP], and manual processing with hydroxyethyl starch [HES] sedimentation) used at Stemlab during a 10-year period. METHODS: Historical data were compiled and the analytical results obtained for the 3 different methods were compared. RESULTS: The manual processing (HES) method yielded the highest level of total nucleated cell recovery after processing, and the AXP system yielded the highest CD34+ cell number. The red blood cell reduction was also significantly higher with the HES method. Also, HES showed comparable results to Toticyte technology for umbilical cord blood (UCB) processing. CONCLUSION: These results show that the HES method is as effective as automated technologies for UCB volume reduction; hence, it is a suitable methodology for private and public UCB banks. The HES method also proved to be superior to Toticyte technology for medical applications, with higher recovery yields of total nucleated cells after thawing and equivalent CD34+ cell recovery and functionality.
ABSTRACT
Blockade of mitogen-activated protein kinase kinase (MEK1/2), part of the extracellular signal-regulated kinase (ERK) or p44/42 mitogen-activated protein kinase (MAPK) pathway has been shown, in some instances, to cause apoptosis in leukemic blast cells. However, studies are contradictory and have often been based mainly on inhibition of cell growth in a limited number of cell lines. This investigation examined the effect of the potent MEK inhibitor U0126 alone and in combination with Ara-C on apoptosis in acute myeloblastic leukemia (AML) cell lines, patient acute leukemic and nonleukemic samples. Apoptosis was assessed flow cytometrically using Apo2.7 and AnnexinV antibodies which detect apoptosis at the mitochondrial and cell membrane levels, respectively. The proapoptotic effect of the inhibitor varied across the five cell lines tested, from highly significant induction of apoptosis to no apparent response. A possible synergistic effect with the combined use of U0126 and Ara-C was observed in one cell line only. The proapoptotic effect of U0126 in the most sensitive cell line appeared to be related to CD34 positivity. Cells from leukemic patients showed considerable sensitivity in two of four cases with a similar association with CD34 expression being evident. Interestingly, control cells did not show a significant effect when exposed to the inhibitor. These results suggest that U0126 may offer a potential alternative to standard chemotherapy with a particular role in the most primitive types of leukemia, these being often the most resistant to standard chemotherapy.
