LAUSR

The survival rate of childhood acute lymphoblastic leukemia (ALL) has increased while that of Philadelphia‐positive (Ph+) ALL remains low. CD19 is a B‐cell specific molecule related to the survival and proliferation of normal B cells. However, there is little information available on the effects of CD19 on the biological behavior of Ph+ ALL cells. In this study, we explored a lentiviral vector‐mediated short hairpin RNA (shRNA) expression vector to stably reduce CD19 expression in Ph+ ALL cell line SUP‐B15 cells and investigated the effects of CD19 downregulation on cell proliferation, apoptosis, drug sensitivity, cell adhesion, cell migration and cell invasion in vitro. CD19 mRNA and protein expression levels were inhibited significantly by CD19 shRNA. Down‐regulation of CD19 could inhibit cell proliferation, adhesion, migration and invasion, and increase cell apoptosis and the efficacy of chemotherapeutic agents and imatinib in SUP‐B15 cells. Moreover, we found that down‐regulation of CD19 expression inhibits cell proliferation and induces apoptosis in SUP‐B15 cells in a p53‐dependent manner. Taken together, our results suggest that lentiviral vector‐mediated RNA interference of CD19 gene may be a promising strategy in the treatment of Ph+ ALL.