FIG. 4.
Senescence-associated marker in Tax- and Ras-expressing human BJ fibroblasts and primary human CD4+ T lymphocytes. (A) Wild-type Tax- or Ras-expressing BJ cells were treated without (nontreated) or with (NAC-treated) NAC, and they were examined after 6 days by SA β-Gal staining. (B) The frequency of senescent β-Gal cells was tabulated as in Fig. 3B. Experiments were performed three times. To obtain enough cell counts for statistical analysis, at least 500 cells in each sample were counted. Error bars show standard deviations. Statistical analysis was performed as described for Fig. 1C. A single asterisk shows a statistically significant difference (P < 0.01), and double asterisks show an absence of significant difference. (C) Wild-type Tax- or Neo-expressing primary human CD4+ T cells were treated without (nontreated) or with (NAC-treated) NAC or with Tax siRNA, and they were examined after 6 days by immunofluorescence for SEN1. (D) The frequency of SEN1 cells was tabulated as in Fig. 3B, and the statistical analysis was as described for Fig. 1C.