Nanobody targeted photodynamic therapy induces cell death of HER2-positive tumor cells

Abstract

SignificanceHuman epidermal growth factor receptor 2 (HER2) protein promotes the growth of cancer cells. Photodynamic therapy (PDT) using nanobodies (NBs) targeting HER2 is a promising treatment strategy for patients with HER2-positive cancers. ApproachIn this study, we evaluated the affinity of pheophorbide A (Pa)-conjugated HER2-targeted NBs (Pa-NB) conjugates for HER2-positive cells and the cytotoxicity induced by PDT using Pa-NB conjugates in vitro. MCF-7 cells with low HER2 expression and SKBR-3 with high HER2 expression were used. ResultsPa-NB conjugates had e high affinity for SKBR-3 cells and selectively induced cell death in them after laser irradiation. Pa-NB conjugates selectively accumulated in vitro. Upon laser irradiation, the Pa-NB conjugates selectively induced significant cytotoxicity in HER2-positive cells. ConclusionsPDT using Pa-NB conjugates, has been suggested as an attractive new therapeutic modality for HER2-positive cancers. Further studies are needed to assess the selectivity and antitumor effects of the Pa-NB conjugates in vivo.