Scientists have identified a new molecule that inhibits proliferation of a broad range of lethal malignant glioma cells in vitro and in vivo.
The findings, published in the May issue of Cancer Cell, shed light on which PI3 kinase family members are most likely to play a role in cancer progression. This study reinforces the concept that successful small molecule kinase inhibitors must display a broad reactivity to effectively attenuate the complex signaling pathways involved in malignant transformation and to thwart to the ability of cancer cells to adapt to stress.
Lipid kinases belonging to the PI3 kinase family, made up of different isoforms, promote cell growth and survival. Aberrant regulation and activation of PI3 kinases has been implicated in several human malignancies. Although the specific mechanisms and PI3K-associated molecules involved in cancer are not clear, this kinase family represents a rational and promising target for design of new cancer therapeutics. Dr. William A. Weiss, from the Department of Neurology at the University of California, San Francisco and coworkers sought to identify which PI3 kinase isoforms are critical for growth and progression of malignant glioma cells. UCSF colleagues Zachary Knight and Kevan Shokat synthesized and characterized a series of novel inhibitors that span the different PI3 kinase isoforms (described in the May issue of Cell). Qi-Wen Fan in the Weiss lab screened these agents in glioma cell lines. One compound, PI-103, uniquely and potently blocked the growth of glioma cells.