Riboflavin binding protein (RfBP)

Riboflavin binding protein (RfBP), also known as riboflavin carrier protein (RCP), is a specialized transport protein essential for the systemic distribution and cellular uptake of riboflavin (vitamin B2) [2, 10]. In humans, RfBP is particularly prominent during pregnancy, where it facilitates the transfer of riboflavin to the developing fetus, and it is also found in the circulatory system as a soluble carrier [10, 13]. The protein has gained significant attention in oncology because it and its associated receptors are highly overexpressed in various malignancies, including breast, prostate, and squamous cell cancers, as well as in the tumor neovasculature [2, 8]. This differential expression makes RfBP a valuable target for active targeting strategies, where riboflavin-conjugated nanoparticles or cytotoxic drugs are used to selectively deliver therapies to tumor cells [1, 3]. Beyond its role as a delivery vehicle, RfBP interacts with small molecule antagonists like quinacrine and chloroquine, which can interfere with the protein's binding capacity and disrupt essential flavin-dependent metabolic pathways in cancer cells [4, 5].

Other names

Riboflavin carrier proteinRCPOvoflavoproteinRiboflavin-flavoprotein

Targeted drug delivery via riboflavin-conjugation and competitive antagonism of riboflavin binding to disrupt cellular metabolism [3, 4, 8].