Cell Lines

The expression of different T-cell oncogenes -including TAL1- was analyzed by quantitative RT-PCR in a panel of T-cell acute lymphoblastic leukemia (T-ALL) cell lines. The line expressing the most TAL1 RNA was found to be Jurkat cell line (Figure 1). High expression of TAL1 protein in Jurkat cells also detected western blot, using a monoclonal antibody against human TAL1 kindly provided by Dr Karen Pulford (data not shown). Jurkat cells were selected to perform the ChIP on chip experiments because of i) being a well-characterized model for T-ALL, ii) its high levels of TAL1 would ensure an higher probability of success for the immunoprecipitation.

The T-ALL Jurkat cell line clone E6-1 was obtained from the American Type Culture Collection (ATCC) (Manassas,VA). Jurkat cells were grown in RPMI media (Invitrogen) with 10% Fetal Bovine Serum (FBS) in a humidified 5% CO2 atmosphere at 37 0C. Jurkat cells were crosslinked for 10 min at room temperature, washed with PBS and stored frozen at -800C until used in ChIP on chip experiments.