Bcl11a promotes expansion of an Nf1-deficient hematopoietic cell line and p21^Cip1 down-regulation. (A) Scheme for generating Nf1^(+/+) or Nf1^(−/−) cell lines stably transduced with Bcl11a-expressing retroviral construct (Nf1+/+.Bcl11a and Nf1−/−.Bcl11a) or with empty vector (Nf1+/+.vector and Nf1−/−.vector) as negative controls. His6 indicates the protein tag of 6 repeats of histidine. (B) Verification of the Bcl11a-expressing vector by transient transfection of 293T cells followed by Western blotting assay. Anti-His antibody was used. The double arrows indicate the signal for Bcl11a. The single arrow indicates a nonspecific (n.s.) signal. (C) Cumulative growth of the stable Bcl11a- or vector-transduced Nf1^(+/+) or Nf1^(−/−) cells. (D) The abundance of cell-cycle regulatory proteins in stable Bcl11a or vector transductants. (E) p21^Cip1 protein level was determined in stable Bcl11a or vector transductants after doxorubicin treatment (Doxo) for 16 hours. Representative results from 3 independent experiments were shown here.