Description
To investigate an unknown mechanism of cytotoxicity, A549 human lung-cancer cells were treated with compounds from a series of inhibitors developed against the human LIM kinases LIMK1 and LIMK2. Compounds 1 and 2 inhibit LIM kinase activity in vitro and affect cell proliferation and survival in vivo. Compounds 3 and 4 inhibit LIM kinases but do not affect cell survival or proliferation. Compounds 5 and 6 affect proliferation and survival but do not inhibit LIM kinases. Nocodazole was included as a comparator because the compounds were known to affect microtubule stability. A treatment of 7 hours was used to examine events prior to apoptosis, while the dose levels captured both cytotoxicity and inhibition of LIMKs (Compounds 1 and 2), LIMK inhibition alone ( Compounds 3 and 4) or cytotoxicity alone (Compounds 5, 6, and Nocodazole).