Figure 2. Expression of UPF1 and UPF2 in MSI and non-MSI (MSS) primary CRCs relative to matched normal colonic mucosa.
In 25 MSI and 31 MSS CRCs we compared the expression of UPF1 and UPF2 between the tumors and matched normal colonic mucosa by real-time quantitative RT-PCR. In all but 5 cases, over-expression of UPF1 was observed in MSI CRC tumors. Considering all samples, the over-expression of UPF1 in MSI tumors was statistically significant (P = 1.5×10−3; paired t-test). In MSS CRCs, a trend for over-expression of this factor was observed under the same conditions (P = 0.08; paired t-test). In patients with MSI or MSS CRCs, UPF2 was not differentially expressed between tumor and matching normal mucosa (P = 0.56 and P = 0.83, respectively; paired t-test).