CRABP1 Recombinant Rabbit mAb (S-4212-76)

CRABP1 (Cellular Retinoic Acid Binding Protein 1) is a member of the fatty acid-binding protein family, whose primary known function is to bind retinoic acid—the active derivative of vitamin A—with high affinity, and is believed to play an important role in retinoic acid-mediated cell differentiation and proliferation. This protein is widely distributed in the cytoplasm, and its three-dimensional structure forms a β-barrel fold that creates an internal cavity capable of accommodating hydrophobic ligands such as retinoic acid. Although binding retinoic acid is its primary known function, the role of CRABP1 in tumor biology is exceptionally complex and exhibits duality: in some epithelial tumors (such as papillary thyroid carcinoma and esophageal squamous cell carcinoma), its gene promoter is silenced by hypermethylation and expression is downregulated, suggesting that it may act as a tumor suppressor; however, in mesenchymal-derived tumors (such as synovial sarcoma) and pancreatic neuroendocrine tumors, CRABP1 displays clear pro-tumor and pro-metastatic activity, with its high expression closely associated with lymph node metastasis and poor differentiation/high-grade malignancy. Moreover, this pro-tumorigenic effect does not depend on its ability to bind retinoic acid, implying that the protein may possess other unknown pro-tumor molecular mechanisms. Overall, the role of CRABP1 in tumorigenesis and progression is highly tissue-dependent—it serves as a potential tumor suppressor in some cancers while acting as a key driver of malignant progression and a candidate prognostic biomarker of poor outcome in others, making its functional diversity an intriguing and complex target in cancer research.