Dataset Information

STK33 kinase inhibitor BRD-8899 has no effect on KRAS-dependent cancer cell viability.

ABSTRACT: Approximately 30% of human cancers harbor oncogenic gain-of-function mutations in KRAS. Despite interest in KRAS as a therapeutic target, direct blockade of KRAS function with small molecules has yet to be demonstrated. Based on experiments that lower mRNA levels of protein kinases, KRAS-dependent cancer cells were proposed to have a unique requirement for the serine/threonine kinase STK33. Thus, it was suggested that small-molecule inhibitors of STK33 might have therapeutic benefit in these cancers. Here, we describe the development of selective, low nanomolar inhibitors of STK33's kinase activity. The most potent and selective of these, BRD8899, failed to kill KRAS-dependent cells. While several explanations for this result exist, our data are most consistent with the view that inhibition of STK33's kinase activity does not represent a promising anti-KRAS therapeutic strategy.

SUBMITTER: Luo T

PROVIDER: S-EPMC3286931 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

STK33 kinase inhibitor BRD-8899 has no effect on KRAS-dependent cancer cell viability.

Luo Tuoping T Masson Kristina K Jaffe Jacob D JD Silkworth Whitney W Ross Nathan T NT Scherer Christina A CA Scholl Claudia C Fröhling Stefan S Carr Steven A SA Stern Andrew M AM Schreiber Stuart L SL Golub Todd R TR

Proceedings of the National Academy of Sciences of the United States of America 20120209 8

Approximately 30% of human cancers harbor oncogenic gain-of-function mutations in KRAS. Despite interest in KRAS as a therapeutic target, direct blockade of KRAS function with small molecules has yet to be demonstrated. Based on experiments that lower mRNA levels of protein kinases, KRAS-dependent cancer cells were proposed to have a unique requirement for the serine/threonine kinase STK33. Thus, it was suggested that small-molecule inhibitors of STK33 might have therapeutic benefit in these can ...[more]

PMID: 22323609

Similar Datasets

Project description:Many human oncogenes are challenging therapeutic targets. An alternative to direct targeting of oncogenes is to perform â??synthetic lethalityâ?? screens for genes that are essential only in the context of specific cancer-causing mutations. We used high-throughput RNA interference (RNAi) to identify synthetic lethal interactions in cancer cells harboring mutant KRAS, the most commonly mutated human oncogene. We find that cells that are dependent on mutant KRAS exhibit sensitivity to suppression of the serine/threonine kinase STK33 irrespective of tissue origin, whereas STK33 is not required by KRAS-independent cells. STK33 promotes cancer cell viability in a kinase activity-dependent manner by regulating the suppression of mitochondrial apoptosis mediated through S6K1-induced inactivation of the death agonist BAD selectively in mutant KRAS-dependent cells. These observations identify STK33 as a target for treatment of the broad spectrum of mutant KRAS-driven cancers, and demonstrate the potential of RNAi screens for discovering critical functional dependencies created by oncogenic mutations that may enable therapeutic intervention for cancers associated with â??undruggableâ?? genetic alterations. NOMO-1 and SKM-1 acute myeloid leukemia (AML) cells were stably transduced with different pLKO.1puro lentiviral shRNA vectors targeting STK33 or a nontargeting control shRNA. VSV-G-pseudotyped lentiviral particles were produced by cotransfection of 293T cells with pLKO.1 constructs and the compatible packaging plasmids pMD.G and pCMVR8.91. Virus was harvested 48 and 72 hours after transfection, cells were incubated with lentiviral supernatants for 30 hours, and infected cells were selected with 2 Âµg/ml puromycin. RNA was isolated after 2 days of puromycin selection and isolation of viable cells by density gradient centrifugation, and gene expression was profiled using GeneChip Human Genome U133 Plus 2.0 microarrays (Affymetrix). Fluorescence ratios were normalized according to the RMA algorithm, and data were filtered as previously described (Bullinger et al. Blood 110:1291-300, 2007) using the BRB-ArrayTools software package. For subsequent analyses, only probe sets with a p-value for the log intensity variation of less than 0.01 were included. Average linkage clustering was used for hierarchical clustering (distance measure, correlation uncentered), and results were visualized using TreeView (Eisen et al. Proc Natl Acad Sci USA 95:14863-14868, 1998). Differentially expressed genes (p < 0.005) were identified by â??class comparison analysisâ?? for paired samples (cell line transduced with an shRNA targeting STK33 versus cell line transduced with a control shRNA) using the BRB-ArrayTools software package (Version 3.3.0 Beta_3; http://linus.nci.nih.gov/BRB-ArrayTools.html) and R (Version 2.2.1; http://www.r-project.org). Screening for an enrichment of genes belonging to distinct BioCarta pathways in the different gene sets was performed with the BRB Pathway Comparison tool computing several statistics, including the Fisher (LS) statistic and the Kolmogorov-Smirnov (KS) statistic. A pathway was considered differentially regulated if the significance level was less than 0.005.

Dataset Information

STK33 kinase inhibitor BRD-8899 has no effect on KRAS-dependent cancer cell viability.

Publications

STK33 kinase inhibitor BRD-8899 has no effect on KRAS-dependent cancer cell viability.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets