PLX296369

GSE136803: ABCB5 is activated by MITF and b-catenin and is associated with melanoma differentiation

• Organsim human
• Type RNASEQ
• Target gene
• Project ARCHS4

Defining markers of different phenotypic states in melanoma is important for understanding disease progression, determining the response to therapy, and defining the molecular mechanisms underpinning phenotype-switching driven by the changing intratumor microenvironment. The ABCB5 transporter is implicated in drug-resistance and has been identified as a marker of melanoma-initiating cells. Indeed, ongoing studies are using ABCB5 to define stem cell populations. However, we show here that the ABCB5 is a direct target for the Microphthalmia-associated transcription factor MITF and its expression can be induced by b-catenin, a key activator and co-factor for MITF. Consequently, ABCB5 mRNA expression is primarily associated with melanoma cells exhibiting differentiation markers. The results suggest first that ABCB5 is unlikely to represent a marker of dedifferentiated melanoma stem cells, and second that ABCB5 may contribute to the non-genetic drug-resistance associated with highly differentiated melanoma cells. To reconcile the apparently conflicting observations in the field we propose a model in which ABCB5 may mark a slow-cycling differentiated population of melanoma cells. SOURCE: Pakavarin Louphrasitthiphol (pakavarin.louphrasitthiphol@ludwig.ox.ac.uk) - Prof. CRGoding Ludwig Institute for Cancer Research