Analysis of exon 11-skipped transcript. (A) RT-PCR analysis of untreated chronic lymphocytic leukemia (CLL) cells and cells treated with emetine (e) or emetine plus actinomycin D (e + A) and assayed for expression of E-cadherin, BIK, and DUSP4. In the top panel, E-cadherin cDNA was amplified with primers at the 3′ end of the gene, In the bottom panel, the E-cadherin cDNA is amplified by primers in the region of exons 10 and 12. The upper points toward the band of expected size, and the lower points toward a DNA fragment lacking exon 11. The next 2 panels show amplification of BIK and DUSP4. Glyceraldehyde-3-phosphate dehydrogenase amplification shown as a control. (B) Time course of emetine-induced up-regulation of E-cadherin RNA. CLL cells treated with emetine for 0, 4, 8, 12, and 16 hours. Primers in the region of exons 10 and 12 were used for amplification of E-cadherin cDNA and give rise to 2 fragments that differ by 146 base pairs in emetine-treated cells due to exon 11 deletion. (C) Sequence of the E-cadherin gene in the region of interest. There is an exon 11 deletion resulting in a frame shift and PTC codon.