Unpaired Student t test was used to compare ALL this website with Control group. Statistical significances are shown between groups only when p ≤ 0.05. Figure 4 Levels of PBX1 – 4 in healthy volunteers vs. patients with leukemia. Box plot graphics showing ΔCP values RG7420 taking ACTB (left panel) or RPL32 (right panel) as reference genes. The graphics display median (dark lines), 25‒75th percentile (boxes), interquartile ranges (whiskers), and outliers (*) from the 14 patients with Acute lymphoblastic leukemia (ALL) and the 19 controls (C). Unpaired Student

t test was used to compare ALL with Control group. Statistical significances are shown between groups only when p ≤ 0.05 MEIS1 Silencing Decreases the Proliferation Rate of Leukemic-derived Cell Lines Because we determined a consistent up-regulation of MEIS1 and PREP1 in cell lines and in samples A-1210477 order of patients with ALL, it was interesting to us to determine which type of advantage provides the high expression of these genes to leukemic cells. First we analyzed the role of MEIS1. The MEIS1 gene has been localized in chromosome 2 and it has been described that Jurkat cells are monosomic for this chromosome, CEM cells have two copies, and K562 cells are trisomic [21]; in this regard, expression of MEIS1 ought to be different in these cell lines. To test this hypothesis, we analyzed MEIS1 baseline

expression in these cell lines by qRT-PCR (Figure 5A). As expected, Jurkat was the cell line with the lowest MEIS1 expression, followed by CEM and K562 expressing highest levels. Taking advantage of the existing different levels of MEIS1 in the Florfenicol cell lines, we utilized Jurkat and K562 cells to investigate whether high MEIS1 expression is related with

increased proliferation. We observed that K562 have a higher proliferation rate than Jurkat cells (Figure 5B). To demonstrate the direct involvement of MEIS1 in this exacerbated proliferation, we performed silencing assays in both cell lines. We employed short hairpin RNAs shRNAs directed to two different regions of MEIS1 mRNA: one was directed to Exon 9 (E9), and the other to Exon 13 (E13). By using recombinant virus, we introduced these sequences into Jurkat and K562 cells. To assure that all infected cells were carrying the construction, a resistance gene to puromycin was also introduced and the infected cells were selected with this antibiotic. Additionally, we infected the cells with an empty virus (without shRNA) and selected them also with puromycin in order to posses a control for the selection and infection process. We then tested MEIS1 (mRNA) levels by qRT-PCR. As shown in Figures 5C and 5E, MEIS1 mRNA levels decrease with both shRNAs in both cell lines to nearly 50% of the initial expression. Employing the MEIS1-silenced cells, we then measured the proliferation rate and observed that proliferation was affected in all clones in which MEIS1 was silenced (Figures 5D and 5F).