Suppression of proline-directed protein kinase FA systemically inhibits the growth of human acute leukemia cells

Initial studies revealed that proline-directed protein kinase FA (PDPK FA) was overexpressed in various cancerous tissues relative to normal controls. However, the functional role of overexpressed PDPK FA in cancer remains to be established. In this report, we explore the potential role of PDPK FA in leukemia cell growth by investigating the effects of partial inhibition of this kinase on human acute promyelocytic leukemia (HL-60) and acute lymphoblastic leukemia (Jurkat) cells. Cloning of PDPK FA cDNA and its recombinant antisense expression vector and antibody were successfully developed. Several stable antisense clones of HL-60 and Jurkat cells were subcloned, which expressed a low level of PDPK FA when compared with the control-transfected clone in immunoblot analysis. Moreover, these antisense clones potently inhibited cell growth, clonogenic growth in soft agar and serum-independent growth. The results taken together demonstrate that suppression of PDPK FA is able to interfere with the growth of HL-60 and Jurkat cells, suggesting an essential role of this PDPK in human acute leukemia cell growth. © 2001 Wiley-Liss, Inc.