Secreted Protein Acidic and Rich in Cysteine (SPARC) and/or Glycoprotein 60 (GP60) (SPARC, GP60)

The primary albumin-binding proteins exploited for drug delivery in oncology are secreted protein acidic and rich in cysteine (SPARC) and glycoprotein 60 (GP60). SPARC is overexpressed in many solid tumors and participates in extracellular matrix remodeling, angiogenesis, and tumor metastasis. GP60, predominantly present on vascular endothelial cells, mediates albumin transcytosis across the endothelium. Albumin-bound drugs, such as nab-paclitaxel (Abraxane), utilize these receptors for selective accumulation and cellular uptake in tumors, enhancing drug delivery by harnessing both passive (EPR effect) and active (receptor-mediated) targeting pathways. Expression levels of SPARC can predict therapeutic response to albumin-formulated drugs. This strategy can circumvent chemotherapy resistance mechanisms such as MDR1-mediated drug efflux, but efficacy and safety can be affected by differential expression of albumin-binding proteins in normal tissues[1][2][3][5].

Other names

OsteonectinBM-40AlbondinAlbumin-binding proteins

Targeted drug delivery: Drugs bound to albumin exploit tumor-expressed albumin receptors for selective uptake by tumor cells ("Trojan horse" approach)\nCircumvention of multidrug resistance (MDR1) by albumin-mediated entry into cancer cells