title: Effects of TrkA inhibitory peptide on cancer-induced pain in a mouse melanoma model.
abstract: OBJECTIVE
  Tropomyosin receptor kinase (Trk) A, a high-affinity receptor of nerve growth factor, is a therapeutic target for both noxious and neuropathic pain. The present study examined the effects of an inhibitory peptide of Trk activity (IPTRK) 3 that inhibits TrkA activity on cancer-induced pain in a mouse melanoma model.
  
  
  METHODS
  The hind paws of mice were inoculated with B16-F1 mouse melanoma cells on day 0. We administered IPTRK3 (20 mg/kg i.p.) repetitively on days 5, 6, 7, 8, and 9, and evaluated pain-related behaviors on days 0, 5, 10, 15, and 20 after tumor inoculation.
  
  
  RESULTS
  Following inoculation, mice demonstrated mechanical allodynia and thermal hyperalgesia with an increased number of flinches, and paw volume increased gradually. However, an intraperitoneal injection of IPTRK3 significantly inhibited mechanical allodynia on day 15 and suppressed the number of flinches on day 20. The increased paw volume was significantly suppressed on day 20 after tumor inoculation. IPTRK3, however, showed no significant effect on thermal hyperalgesia.
  
  
  CONCLUSIONS
  These results suggest that TrkA inhibitory peptide likely suppress melanoma-induced pain with concomitant reduction in the increased paw volume in a mouse skin cancer pain model.
authors.affiliation: Department of Anesthesiology and Reanimatology, Faculty of Medical Sciences, University of Fukui, Eiheijicho, Fukui, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Tabata
authors.forename: Eri
authors.initials: E
authors.lastname: Murata
authors.forename: Koyo
authors.initials: K
authors.lastname: Ueda
authors.forename: Nahoko
authors.initials: N
authors.lastname: Kato-Kogoe
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kuroda
authors.forename: Munetaka
authors.initials: M
authors.lastname: Hirose
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001522:Behavior, Animal; D001835:Body Weight / Q000187:drug effects; D045744:Cell Line, Tumor; D002463:Cell Membrane Permeability; D049109:Cell Proliferation / Q000187:drug effects; D005528:Foot / Q000473:pathology; D007150:Immunohistochemistry; D007274:Injections, Intraperitoneal; D008297:Male; D008546:Melanoma, Experimental / Q000150:complications* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D020932:Nerve Growth Factor / Q000494:pharmacology; D010148:Intractable Pain / Q000188:drug therapy* / Q000209:etiology / Q000523:psychology; D010766:Phosphorylation; D020917:Receptor, trkA / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D020932:Nerve Growth Factor; D020917:Receptor, trkA