Characterising the cellular activity of new Fibroblast Growth Factor Receptor tyrosine kinase inhibitors and identification of a gatekeeper mutation in FGFR3 as a mechanism of acquired resistance.
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ABSTRACT: Fibroblast growth factor receptors (FGFRs) can act as driving oncoproteins in certain cancers due to mutation, over-expression or activating gene fusions and are therefore attractive drug targets. Here we have characterized tumour cell responses to three new inhibitors of FGFR1-3, AZ12576089, AZ12908010 and the clinical candidate AZD4547, making comparisons with the well-characterized FGFR inhibitor PD173074. Using a panel of 16 human tumour cell lines we show that the anti-proliferative activity of AZ12908010 and AZD4547 is strongly linked to the presence of de-regulated FGFR signalling. In contrast, AZ12576089 was also able to inhibit proliferation of cells lacking de-regulated FGFR, suggesting off-target effects. Acquired resistance to targeted tyrosine kinase inhibitors (TKIs) is a growing problem in the clinic. To assess how FGFR-dependent tumour cells may adapt to long-term exposure to FGFR inhibitors we generated a derivative of the KMS-11 myeloma cell line (FGFRY373C) with acquired resistance to AZ12908010 (KMS-11R cells). Basal P-FGFR3, P-FRS2 and P-ERK1/2 and D-type cyclins were all inhibited by AZ12908010 in parental KMS-11 cells whereas these markers were constitutively elevated and refractory to drug in KMS-11R cells. Sequencing of FGFR3 in KMS-11R cells revealed the presence of a heterozygous mutation at the gatekeeper residue, encoding FGFR3V555M. Consistent with this KMS-11R cells were cross-resistant to AZD4547 and PD173074 but remained fully sensitive to AZ12576089, confirming that the anti-proliferative effects of AZ12576089 are not related to FGFR inhibition. These results define the selectivity and efficacy of two new FGFR inhibitors and identify a secondary gatekeeper mutation as a mechanism of acquired resistance to FGFR inhibitors that should be anticipated as clinical evaluation proceeds.
ORGANISM(S): Homo sapiens
SUBMITTER: Simon Andrews
PROVIDER: E-TABM-1222 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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