Figure 3. SIGIRR^ΔE8 is a common variant in colon cancer cells with reduced complex glycan modification.

A. VACO 400 cells were transfected with FLAG-tagged SIGIRR(+) or empty vector followed bywestern blot. B. RNA from Vaco400 cells was used for 5’ RACE analysis using primer targeting 5’ end (RACE P) and oligo-dT targeting polyA tail. The product from the reaction was resolved on a 1.5% agarose gel. C. Quantitative analysis of the of SIGIRR^ΔE8 versus full-length SIGIRR transcript expressed as percentage of the SIGIRR^ΔE8 in normal colonic epithelial cells, colorectal cancer tissue and colon cancer cell lines. Locations of amplicons used in the assay are indicated in B (A1 and A2) D. Indicated amounts of full-length SIGIRR or SIGIRR^ΔE8 were transfected into HeLa cells together with NFκB dependent luciferase followed by luciferase assay and western blot. E. 3μg of full-length SIGIRR or SIGIRR^ΔE8 cDNA was transfected into HeLa cells. 8 hours after transfection, cells were treated with 5ng/mL kifunensine for indicated time and harvested for western blot analysis. Error bar represents standard error of mean (S.E.M.) of 3 technical replicates.