MITF Modulates Therapeutic Resistance through EGFR Signaling

Response to targeted therapies varies significantly despite shared oncogenic mutations. Nowhere is this more apparent than in BRAF (V600E)-mutated melanomas where initial drug response can be striking and yet relapse is commonplace. Resistance to BRAF inhibitors have been attributed to the activation of various receptor tyrosine kinases (RTKs), although the underlying mechanisms have been largely uncharacterized. Here, we found that EGFR-induced vemurafenib resistance is ligand dependent. We employed whole-genome expression analysis and discovered that vemurafenib resistance correlated with the loss of microphthalmia-associated transcription factor (MITF), along with its melanocyte lineage program, and with the activation of EGFR signaling. An inverse relationship between MITF, vemurafenib resistance, and EGFR was then observed in patient samples of recurrent melanoma and was conserved across melanoma cell lines and patients' tumor specimens. Functional studies revealed that MITF depletion activated EGFR signaling and consequently recapitulated the resistance phenotype. In contrast, forced expression of MITF in melanoma and colon cancer cells inhibited EGFR and conferred sensitivity to BRAF/MEK inhibitors. These findings indicate that an "autocrine drug resistance loop" is suppressed by melanocyte lineage signal(s), such as MITF. This resistance loop modulates drug response and could explain the unique sensitivity of melanomas to BRAF inhibition..

Medienart:

Artikel

Erscheinungsjahr:

2015

Erschienen:

2015

Enthalten in:

Zur Gesamtaufnahme - volume:135

Enthalten in:

The journal of investigative dermatology - 135(2015), 7, Seite 1863-1872

Sprache:

Englisch

Beteiligte Personen:

Ji, Zhenyu [VerfasserIn]
Erin Chen, Yiyin [Sonstige Person]
Kumar, Raj [Sonstige Person]
Taylor, Michael [Sonstige Person]
Jenny Njauw, Ching-Ni [Sonstige Person]
Miao, Benchun [Sonstige Person]
Frederick, Dennie T [Sonstige Person]
Wargo, Jennifer A [Sonstige Person]
Flaherty, Keith T [Sonstige Person]
Jönsson, Göran [Sonstige Person]
Tsao, Hensin [Sonstige Person]

Links:

Volltext
www.ncbi.nlm.nih.gov
lup.lub.lu.se

Themen:

Cell Proliferation - drug effects
Cell Proliferation - genetics
Drug Resistance, Neoplasm - genetics
Indoles - pharmacology
Melanoma - drug therapy
Melanoma - genetics
Microphthalmia-Associated Transcription Factor - drug effects
Microphthalmia-Associated Transcription Factor - genetics
Molecular Targeted Therapy - methods
Proto-Oncogene Proteins B-raf - drug effects
Proto-Oncogene Proteins B-raf - genetics
Receptor, Epidermal Growth Factor - drug effects
Receptor, Epidermal Growth Factor - metabolism
Sulfonamides - pharmacology
Tumor Cells, Cultured - drug effects

RVK:

RVK Klassifikation

doi:

10.1038/jid.2015.105

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

OLC1964636698