title: Preparation and Characterization of Gelonin-Melittin Fusion Biotoxin for Synergistically Enhanced Anti-Tumor Activity.
abstract: To investigate the applicability of fusion biotoxins combining pore-forming toxins (PFTs) and ribosome-inactivating proteins (RIPs) for the anti-cancer treatment.
  
  
  
  Membrane active PFTs tend to destabilize cell membranes of tumor cells, but lack a warhead inducing significant cause of cell death. Cell-impermeable RIPs possess a powerful warhead, yet not able to enter the tumor cells. To address these challenges for anti-tumor effects, we introduced a fusion strategy of conjugating melittin (a PFT) and gelonin (a type 1 RIP) via chemical and recombinant methods, followed by in vitro assays and in vivo animal studies.
  
  
  
  In vitro characterization results confirmed that the chimeric gelonin-melittin fusion proteins retained equivalent intrinsic activity to that of unmodified gelonin in inhibiting protein translation. However, chemically conjugated gelonin-melittin (cGel-Mel) and recombinant chimeric gelonin-melittin fusion (rGel-Mel) exhibited greater cell uptake, yielding a significantly enhanced cytotoxic activity over treatment of gelonin, melittin or physical mixture of gelonin and melittin. Remarkably, cGel-Mel and rGel-Mel displayed 32- and 10-fold lower IC50 than gelonin in the cell lines. The superior anti-tumor efficacy of multivalent cGel-Mel to monovalent rGel-Mel suggested that valency could be a crucial factor for the extent of melittin-mediated cell uptake. Tumoricidal effects observed from animal studies were in good accordance with our findings from the cellular assays.
  
  
  
  This study successfully demonstrated that fusion of biotoxins could provide a simple yet effective way to synergistically augment their anti-tumor activity.
authors.affiliation: College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, 501 Jinju Daero, Jinju, Gyeongnam, 52828, Republic of Korea.|Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI 48109, USA.
authors.forename: Meong Cheol
authors.initials: MC
authors.lastname: Shin
authors.affiliation: College of Pharmacy and Research Institute of Pharmaceutical Sciences, Gyeongsang National University, 501 Jinju Daero, Jinju, Gyeongnam, 52828, Republic of Korea.|Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI 48109, USA.|College of Pharmacy, Inje University, 197 Injero, Gimhae, Gyeongnam, 50834, Republic of Korea.
authors.forename: Kyoung Ah
authors.initials: KA
authors.lastname: Min
authors.affiliation: Comparative Biomedicine Research Branch, Division of Cancer Biology, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu, Goyang, Gyeonggi-do, 10408, Republic of Korea.
authors.forename: Heesun
authors.initials: H
authors.lastname: Cheong
authors.affiliation: College of Pharmacy, Sunchon National University, 255 Jungang-ro, Suncheon, Jeonnam 57922, Republic of Korea.
authors.forename: Cheol
authors.initials: C
authors.lastname: Moon
authors.affiliation: Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Hai-ke Rd., Shanghai 201203, China.
authors.forename: Yongzhuo
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China.
authors.forename: Huining
authors.initials: H
authors.lastname: He
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan, 428 Church St., Ann Arbor, MI 48109, USA.|Tianjin Key Laboratory on Technologies Enabling Development of Clinical Therapeutics and Diagnosis, School of Pharmacy, Tianjin Medical University, Tianjin 300070, China.
authors.forename: Victor C
authors.initials: VC
authors.lastname: Yang
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry* / Q000494:pharmacology; D002460:Cell Line; D045744:Cell Line, Tumor; D004285:Dogs; D006367:HeLa Cells; D006801:Humans; D061985:Madin Darby Canine Kidney Cells; D008555:Melitten / Q000737:chemistry* / Q000494:pharmacology; D051379:Mice; D009369:Neoplasms / Q000188:drug therapy; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000494:pharmacology; D054788:Ribosome Inactivating Proteins / Q000737:chemistry / Q000494:pharmacology; D054789:Ribosome Inactivating Proteins, Type 1 / Q000737:chemistry* / Q000494:pharmacology; D014118:Toxins, Biological / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D011993:Recombinant Fusion Proteins; D054789:Ribosome Inactivating Proteins, Type 1; D014118:Toxins, Biological; D008555:Melitten; C025674:GEL protein, Gelonium multiflorum; D054788:Ribosome Inactivating Proteins
keywords: cancer; gelonin; melittin; ribosome inactivating protein; toxin