Figure 4.

(A) UCH-L1 gene activity and (B) UCH-L1 protein were exclusively downregulated in the presence of EGFcyt, EGF22.23, and mbEGFctF. (C) Specific 10-to 12-mer peptides covering the complete EGFcyt peptide region encoded by exons 22 and 23 were used to determine the specificity of exon-derived peptides for the silencing of UCH-L1 by EGFcyt. Exclusively peptides encoded by the exon 23-derived peptide sequences of EGFcyt, but not scrambled peptides or peptides derived from pEGFcyt exon 22, were capable of downregulating UCH-L1 expression at the gene and protein levels. Representative immunodetection of UCH-L1 in (D) papillary and (E) undifferentiated human thyroid cancer tissues. (F and G) No specific immunostaining was detected in normal human thyroid tissues (data not shown) and when the primary antiserum was replaced by a species-specific nonimmune serum at the same concentration. Magnification, x20.