title: Targeting signal transducer and activator of transcription 3 with G-quartet oligonucleotides: a potential novel therapy for head and neck cancer.
abstract: Signal transducer and activator of transcription 3 (Stat3) is a critical mediator of oncogenic signaling activated frequently in many types of human cancer where it contributes to tumor cell growth and resistance to apoptosis. Stat3 has been proposed as a promising target for anticancer drug discovery. Recently, we developed a series of G-quartet oligodeoxynucleotides (GQ-ODN) as novel and potent Stat3 inhibitors, which significantly suppressed the growth of prostate and breast tumors in nude mice. In the present study, we showed that GQ-ODN specifically inhibited DNA-binding activity of Stat3 as opposed to Stat1. Computer-based docking analysis revealed that GQ-ODN predominantly interacts with the SH2 domains of Stat3 homodimers to destabilize dimer formation and disrupt DNA-binding activity. We employed five regimens in the treatment of nude mice with tumors of head and neck squamous cell carcinoma (HNSCC): placebo, paclitaxel, GQ-ODN T40214, GQ-ODN T40231, and T40214 plus paclitaxel. The mean size of HNSCC tumors over 21 days only increased by 1.7-fold in T40214-treated mice and actually decreased by 35% in T40214 plus paclitaxel-treated mice whereas the mean size of HNSCC tumors increased 9.4-fold in placebo-treated mice in the same period. These findings show that GQ-ODN has potent activity against HNSCC tumor xenografts alone and in combination with paclitaxel.
authors.affiliation: Department of Medicine and Cancer Center, Baylor College of Medicine, One Baylor Plaza, N520, Houston, TX 77030, USA. njing@bcm.tmc.edu
authors.forename: Naijie
authors.initials: N
authors.lastname: Jing
authors.forename: Qiqing
authors.initials: Q
authors.lastname: Zhu
authors.forename: Ping
authors.initials: P
authors.lastname: Yuan
authors.forename: Yidong
authors.initials: Y
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Mao
authors.forename: David J
authors.initials: DJ
authors.lastname: Tweardy
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017209:Apoptosis; D004273:DNA, Neoplasm / Q000187:drug effects; D016503:Drug Delivery Systems; D006147:Guanine / Q000737:chemistry; D006258:Head and Neck Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009838:Oligodeoxyribonucleotides / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use*; D017239:Paclitaxel / Q000627:therapeutic use; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors* / Q000235:genetics; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D004273:DNA, Neoplasm; C510005:GQ-ODN T40214; C510006:GQ-ODN T40231; D009838:Oligodeoxyribonucleotides; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D006147:Guanine; D017239:Paclitaxel