Expression levels of HOXA9 targets in primary samples of AML. (A) Gene expression profiles for 28 human primary AML patient samples were downloaded from the www.genome.wi.mit.edu/MPR website.16 HOXA9 expression levels were used to divide the samples into 2 groups. High HOXA9 samples had pixel intensities ranging from 2000 to 6000 (n = 17) and low HOXA9-expressing samples had pixel intensity values of 2000 or below (n = 11). A Student t test was performed to determine which gene expression differences were statistically significant. *P < .05; **P < .001. Fourteen genes whose expression was significantly different between the HOXA9-high and HOXA9-low groups of primary AML showed the same direction of change of expression as seen in the microarray studies. (B) JUNB mRNA levels in high and low HOXA9-expressing AML patient samples, as measured by quantitative real-time PCR. Samples were segregated into one of 2 groups, based on relative expression of HOXA9, and normalized to GAPDH. High HOXA9-expressing samples had HOXA9/GAPDH ratios of more than 0.05 (n = 4), and low HOXA9 samples had ratios less than 0.05 (n = 7). Values for JUNB represent the mean relative expression level for each HOXA9 expression group.
