ABCB5

ATP-binding cassette sub-family B member 5 also known as P-glycoprotein ABCB5 is a plasma membrane-spanning protein that in humans is encoded by the ABCB5 gene. ABCB5 is an ABC transporter and P-glycoprotein family member principally expressed in physiological skin and human malignant melanoma.

ABCB5 has been suggested to regulate skin progenitor cell fusion and mediate chemotherapeutic drug resistance in stem-like tumor cell subpopulations in human malignant melanoma. It is commonly over-expressed on circulating melanoma tumour cells. Furthermore, the ABCB5+ melanoma- initiating cells were demonstrated to express FLT1 (VEGFR1) receptor tyrosine kinase which was functionally required for efficient xenograft tumor formation, as demonstrated by shRNA knockdown experiments.