Figure 2.

Snail knockdown induces cellular senescence in IMR90. (A and B) Thirty‐six hours after transfection of control siRNA (NC) or two kinds of Snail siRNAs (#1 and #2) into IMR90 cells, expression levels of Snail were examined by qRT‐PCR (A) and immunoblotting following treatment with 1 ng·mL⁻¹ of TGF‐β for 3 h (B). α‐Tubulin levels were monitored as a loading control (B). (C) Five days after transfection with control siRNA (NC) or Snail siRNAs (#1 and #2), IMR90 cells were subjected to SA‐β‐gal staining; photographs were taken (upper panel) to count the number of SA‐β‐gal‐positive cells (lower panel). (D) IMR90 cells treated with 1 ng·mL⁻¹ of TGF‐β for 7 days were subjected to SA‐β‐gal staining; photographs were taken (top panel), immunoblotting was performed (middle panel), and SA‐β‐gal‐positive cells were counted (bottom panel). Each value in (A, C, and D) represents the mean ± SD of triplicate determinations from a representative experiment. Similar results were obtained at least three independent experiments (A–D). *P < 0.05, **P < 0.01, ANOVA test.