title: Increase of doxorubicin sensitivity for folate receptor positive cells when given as the prodrug N-(phenylacetyl) doxorubicin in combination with folate-conjugated PGA.
abstract: Folate receptor (FR) has been proposed as a promising target for tumor drug targeting. The aim of this study was to increase the chemo-sensitivity of FR-positive cells to doxorubicin by folate-directed enzyme prodrug therapy (FDEPT). Folate conjugated penicillin-G amidase was prepared and its ability to hydrolyze N-(phenylacetyl) doxorubicin was measured by HPLC. Fluorescence and confocal image analysis revealed that Folate-PGA can be specifically delivered into FR-positive HeLa and SKOV3 tumor cells. In vitro cytotoxity assays, IC50 was reduced with N-(phenylacetyl) doxorubicin versus doxorubicin for HeLa (3.1-fold reduction; p<0.001) and SKOV3 (3.3-fold reduction; p<0.001) when Folate-PGA was specifically bound to the cells. Complete activation was confirmed in HeLa and SKOV3 cells pretreated with free folic acid (1 mM), where the combination of N-(phenylacetyl) doxorubicin with Folate-PGA did not show any significant cell toxicity to the IC50 of doxorubicin. Pharmacokinetic clearance and biodistribution studies in vivo showed that 125I-Folate-PGA was cleared from blood within 24 h and had significantly higher tumor uptake compared to 125I-PGA (p<0.05). These results demonstrate that the FDEPT approach may be a potential promising strategy to improve chemotherapy-resistant cancers therapeutic ratio and warranted future studies.
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Guangya
authors.initials: G
authors.lastname: Xiang
authors.forename: Youjiu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Keya
authors.initials: K
authors.lastname: Yang
authors.forename: Wo
authors.initials: W
authors.lastname: Fan
authors.forename: Jialiang
authors.initials: J
authors.lastname: Lin
authors.forename: Fanbo
authors.initials: F
authors.lastname: Zeng
authors.forename: Jizhou
authors.initials: J
authors.lastname: Wu
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004317:Doxorubicin / Q000494:pharmacology*; D016503:Drug Delivery Systems; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D005260:Female; D058973:Folate Receptors, GPI-Anchored; D005492:Folic Acid / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D010399:Penicillin Amidase / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D011355:Prodrugs / Q000494:pharmacology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D000903:Antibiotics, Antineoplastic; D002352:Carrier Proteins; D058973:Folate Receptors, GPI-Anchored; D011355:Prodrugs; D011956:Receptors, Cell Surface; D004317:Doxorubicin; D005492:Folic Acid; D010399:Penicillin Amidase