Dynamic Reprogramming of the Kinome in Response to Targeted MEK Inhibition in Triple-Negative Breast Cancer

Abstract

SUMMARY Kinase inhibitors have limited success in cancer treatment because tumors circumvent their action. Using a quantitative proteomics approach, we assessed kinome activity in response to MEK inhibition in triple negative breast cancer (TNBC) cells and genetically engineered mice (GEMMs). MEK inhibition caused acute ERK activity loss, resulting in rapid c-Myc degradation that induced expression and activation of several receptor tyrosine kinases (RTKs). RNAi knockdown of ERK or c-Myc mimicked RTK induction by MEK inhibitors, whereas prevention of proteasomal c-Myc degradation blocked kinome reprogramming. MEK inhibitor-induced RTK stimulation overcame MEK2 but not MEK1 inhibition, reactivating ERK and producing drug resistance. The C3Tag GEMM for TNBC similarly induced RTKs in response to MEK inhibition. The inhibitor-induced RTK profile suggested a kinase inhibitor combination therapy that produced GEMM tumor apoptosis and regression where single agents were ineffective. This approach defines mechanisms of drug resistance, allowing rational design of combination therapies for cancer.

Preferential killing of p53-deficient cancer cells by reversine

“…In support of this hypothesis, it has previously been shown that relatively unspecific kinase inhibitors may have broader anticancer effects than highly-targeted agents 47 and/or may avoid the compensatory activation of pathways that sustain cell survival. 48 As an example, the combination of several tyrosine kinase inhibitors with different specificities, as well as elevated concentrations of a single compound, reportedly lead to a rapid collapse of the tyrosine kinase network, resulting in efficient cell killing. 49 What are the mechanisms through which the inactivation of p53 augments the susceptibility of cancer cells to the cytotoxic effects of high-dose reversine?…”

Kinase detection with gallium nitride based high electron mobility transistors

“…2 Monitoring of the entire kinome gave a better overall view of drug efficacy than by monitoring the activity of a single kinase where drug resistance often develops by compensatory upregulation of uninhibited kinases. 2 Another clinical application of the kinase affinity assay was in drug development through determining kinase inhibitor drug targets. 3 Cell lysates were treated with soluble kinase inhibitors, and the lysates were exposed to the affinity beads.…”

“…2 Affinity is in turn affected by kinase activation state as regulated by phosphorylation. 2,3 Basic science and clinical applications exist for the kinase affinity assay. An example basic science application was the monitoring of cell cycle kinase phosphorylation status.…”

“…2 Label-free methods of kinome activity profiling are ideal due to elimination of artifacts caused by changes to kinase characteristics with labeling. 3 An important label-free method of kinome activity measurement is the kinase affinity assay.…”

Preclinical Evaluation of a Novel Orally Available SRC/Raf/VEGFR2 Inhibitor, SKLB646, in the Treatment of Triple-Negative Breast Cancer

“…The Cancer Genome Atlas (TCGA) analysis has determined that about 80% of basal-like TNBC have some degree of genomic amplification or activation of major components of the MAPK signaling network (16). Though both Raf and MEK are the important central nodes in the MAPK pathway, MEK inhibitors in TNBC could induce the activation of several upstream receptor tyrosine kinases through negative feedback, which can reactivate ERK and lead to drug resistance (17). All of these suggest that Raf other than MEK is a better target for the MAPK pathway-targeting therapy of TNBC.…”