Fig. 3From: Unphosphorylated STAT3 in heterochromatin formation and tumor suppression in lung cancerSTAT3 and HP1α affect cellular senescence and major satellite transcription. (a) Representative images are shown of A549 cells stably expressing the indicated STAT3 or HP1α transgenes assayed for senescence-associated beta-galactosidase (SA-β-gal; blue) at pH 6.0 [53]. Control cells were parent A549 cells without transgene expression. (b) Cell senescence was quantified by measuring senescence-associated β-Gal staining at an absorbance of 405 nm. (c) Total RNA was isolated from A549 cells stably expressing the indicated transgene, and were quantified for major satellite transcripts using qRT-PCR. GAPDH gene transcript was used as the internal control for expression. The mean value ± s.d. (standard deviation) was calculated in each group. * P < 0.05, ** P < 0.01Back to article page