MYC expression is dependent on TEL-AML1–mediated STAT3 activity. (A) Quantitative reverse-transcription polymerase chain reaction analysis of MYC mRNA expression 6 hours after treatment with 50 µM S3I-201, 50 µM NSC23766, or dimethylsulfoxide in Reh, At-2, and 697 cells. Columns represent mean ± standard deviation of quadruplicate measurements. (B-E) Western blot analysis of MYC protein expression in Reh and At-2 cells 24 hours after treatment with 50 µM S3I-201 (B), or 50 µM NSC23766 (C), or 6 days after transduction with control scramble, STAT3 (shSTAT3) shRNA (D), or shTA shRNA (E). Numbers represent densitometric quantitation of MYC bands normalized to GAPDH (B-D) and HSP90 (E). Percentage of apoptotic Annexin V⁺PI^- cells (F) and S-phase cells (G) 6 days after transduction with scramble or 2 different MYC (shMYC) shRNA. Data are representative of 2 (D) and 3 (A-G) independent experiments and show mean ± standard deviation of triplicate measurements. *P < .05, **P < .01, ***P < .005 compared with control (Student unpaired t test). GAPDH, glyceraldehyde-3-phosphate dehydrogenase.