BR2 is one of the cell-penetrating peptides (CCPs), a Buforin IIb derivative.
BR2 was found to have cancer-specificity without toxicity to normal cells. After specifically targeting cancer cells through interaction with gangliosides, BR2 entered cells via lipid-mediated macropinocytosis. Moreover, BR2 showed higher membrane translocation efficiency than the well-known CPP Tat (49–57). The capability of BR2 as a cancer-specific drug carrier was demonstrated by fusion of BR2 to a single-chain variable fragment (scFv) directed toward a mutated K-ras (G12V). BR2-fused scFv induced a higher degree of apoptosis than Tat-fused scFv in K-ras mutated HCT116 cells. These results suggest that the novel cell-penetrating peptide BR2 has great potential as a useful drug delivery carrier with cancer cell specificity.
Yu T, Shi Y, Pan X, Feng Q, Wang P, Song S, Yang L, Yang J. BR2 cell penetrating peptide effectively delivers anti-p21Ras scFv to tumor cells with ganglioside expression for therapy of ras-driven tumor. PLoS One. 2022 Jun 1;17(6):e0269084.