Sodium-dependent multivitamin transporter (SMVT) (SMVT)

The Sodium-dependent multivitamin transporter (SMVT), encoded by the SLC5A6 gene, is a transmembrane protein that mediates the sodium-dependent uptake of biotin (Vitamin B7), pantothenic acid (Vitamin B5), and lipoic acid. It is the primary mechanism for biotin acquisition in mammals and is widely expressed in tissues with high metabolic activity, such as the liver, intestine, and kidney. In the context of oncology, SMVT is frequently overexpressed in various aggressive cancer cell lines, including those of the breast, lung, colon, and ovary, to support the increased demand for vitamins required for rapid cell proliferation. This differential expression between tumor and normal tissues has led to the development of biotin-conjugated prodrugs and delivery systems, often referred to as "biotin receptor-targeted" therapies. These agents utilize biotin as a targeting ligand to trigger receptor-mediated endocytosis, thereby enhancing the intracellular delivery of cytotoxic payloads like taxoids or camptothecins. While SMVT is technically a transporter rather than a signaling receptor, its role as a gateway for biotin-functionalized therapeutics makes it a significant target for improving the selectivity and efficacy of cancer treatments.

Other names

Biotin receptorSLC5A6Sodium-dependent multivitamin transporterMultivitamin transporterSolute carrier family 5 member 6Vitamin H transporter

Receptor-mediated endocytosis of biotin-conjugated therapeutic agents