Effective and selective targeting of leukemia cells using a TORC1/2 kinase inhibitor.

Published

Journal Article

Targeting the mammalian target of rapamycin (mTOR) protein is a promising strategy for cancer therapy. The mTOR kinase functions in two complexes, TORC1 (target of rapamycin complex-1) and TORC2 (target of rapamycin complex-2); however, neither of these complexes is fully inhibited by the allosteric inhibitor rapamycin or its analogs. We compared rapamycin with PP242, an inhibitor of the active site of mTOR in both TORC1 and TORC2 (hereafter referred to as TORC1/2), in models of acute leukemia harboring the Philadelphia chromosome (Ph) translocation. We demonstrate that PP242, but not rapamycin, causes death of mouse and human leukemia cells. In vivo, PP242 delays leukemia onset and augments the effects of the current front-line tyrosine kinase inhibitors more effectively than does rapamycin. Unexpectedly, PP242 has much weaker effects than rapamycin on the proliferation and function of normal lymphocytes. PI-103, a less selective TORC1/2 inhibitor that also targets phosphoinositide 3-kinase (PI3K), is more immunosuppressive than PP242. These findings establish that Ph(+) transformed cells are more sensitive than normal lymphocytes to selective TORC1/2 inhibitors and support the development of such inhibitors for leukemia therapy.

Full Text

Duke Authors

Cited Authors

  • Janes, MR; Limon, JJ; So, L; Chen, J; Lim, RJ; Chavez, MA; Vu, C; Lilly, MB; Mallya, S; Ong, ST; Konopleva, M; Martin, MB; Ren, P; Liu, Y; Rommel, C; Fruman, DA

Published Date

  • February 2010

Published In

Volume / Issue

  • 16 / 2

Start / End Page

  • 205 - 213

PubMed ID

  • 20072130

Pubmed Central ID

  • 20072130

Electronic International Standard Serial Number (EISSN)

  • 1546-170X

International Standard Serial Number (ISSN)

  • 1078-8956

Digital Object Identifier (DOI)

  • 10.1038/nm.2091

Language

  • eng