title: Chondroitin sulfate as a molecular portal that preferentially mediates the apoptotic killing of tumor cells by penetratin-directed mitochondria-disrupting peptides.
abstract: The use of cell-penetrating peptides (CPPs) as drug carriers for targeted therapy is limited by the unrestricted cellular translocation of CPPs. The preferential induction of tumor cell death by penetratin (Antp)-directed peptides (PNC27 and PNC28), however, suggests that the CPP Antp may contribute to the preferential cytotoxicity of these peptides. Using PNC27 as a molecular model, we constructed three novel peptides (PT, PR9, and PD3) by replacing the leader peptide Antp with one of three distinct CPPs (TAT, R9, or DPV3), respectively. The IC(50) values of PNC27 in tumor cells were 2-3 times lower than in normal cells. However, all three engineered peptides demonstrated similar cytotoxic effects in tumor and normal cells. Another three chimeric peptides containing the leader peptide Antp with different mitochondria-disrupting peptides (KLA-Antp (KGA), B27-Antp (BA27), and B28-Antp (BA28)), preferentially induced apoptosis in tumor cells. The IC(50) values of these peptides (3-10 microM) were 3-6 times lower in tumor cells than in normal cells. In contrast, TAT-directed peptides (TAT-KLA (TK), TAT-B27 (TB27), and TAT-B28 (TB28)), were cytotoxic to both tumor and normal cells. These data demonstrate that the leader peptide Antp contributes to the preferential cytotoxicity of Antp-directed peptides. Furthermore, Antp-directed peptides bind chondroitin sulfate (CS), and the removal of endogenous CS reduces the cytotoxic effects of Antp-directed peptides in tumor cells. The overexpression of CS in tumor cells is positively correlated to the cell entry and cytotoxicity of Antp- directed peptides. These results suggest that CS overexpression in tumor cells is an important molecular portal that mediates the preferential cytotoxicity of Antp-directed peptides.
authors.affiliation: Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, West China Hospital, Sichuan University, Chengdu 610041, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Yang
authors.forename: Shan
authors.initials: S
authors.lastname: Liu
authors.forename: Huawei
authors.initials: H
authors.lastname: Cai
authors.forename: Lin
authors.initials: L
authors.lastname: Wan
authors.forename: Shengfu
authors.initials: S
authors.lastname: Li
authors.forename: Youping
authors.initials: Y
authors.lastname: Li
authors.forename: Jingqiu
authors.initials: J
authors.lastname: Cheng
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Lu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001692:Biological Transport / Q000187:drug effects; D002352:Carrier Proteins / Q000378:metabolism / Q000494:pharmacology*; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D057846:Cell-Penetrating Peptides; D002809:Chondroitin Sulfates / Q000494:pharmacology*; D005260:Female; D006025:Glycosaminoglycans / Q000378:metabolism / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism*; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000494:pharmacology / Q000627:therapeutic use; D023041:Xenograft Model Antitumor Assays
chemical_list: D002352:Carrier Proteins; D057846:Cell-Penetrating Peptides; D006025:Glycosaminoglycans; C549751:PNC-27; D010455:Peptides; D016159:Tumor Suppressor Protein p53; D002809:Chondroitin Sulfates; C414409:penetratin