title: Behavioral characteristics of a mouse model of cancer pain.
abstract: Pain is a major symptom in cancer patients, and most cancer patients with advanced or terminal cancers suffer from chronic pain related to treatment failure and/or tumor progression. In the present study, we examined the development of cancer pain in mice. Murine hepatocarcinoma cells, HCa-1, were inoculated unilaterally into the thigh or the dorsum of the foot of male C3H/HeJ mice. Four weeks after inoculation, behavioral signs were observed for mechanical allodynia, cold allodynia, and hyperalgesia using a von Frey filament, acetone, and radiant heat, respectively. Bone invasion by the tumor commenced from 7 days after inoculation of tumor cells and was evident from 14 days after inoculation. Cold allodynia but neither mechanical allodynia nor hyperalgesia was observed in mice that received an inoculation into the thigh. On the contrary, mechanical allodynia and cold allodynia, but not hyperalgesia, were developed in mice with an inoculation into the foot. Sometimes, mirror-image pain was developed in these animals. These results suggest that carcinoma cells injected into the foot of mice may develop severe chronic pain related to cancer. This animal model of pain would be useful to elucidate the mechanisms of cancer pain in humans.
authors.affiliation: Medical Research Center, Department of Physiology, Brain Research Institue, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea.
authors.forename: Bae Hwan
authors.initials: BH
authors.lastname: Lee
authors.forename: Jinsil
authors.initials: J
authors.lastname: Seong
authors.forename: Un Jeng
authors.initials: UJ
authors.lastname: Kim
authors.forename: Ran
authors.initials: R
authors.lastname: Won
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Kim
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D001842:Bone and Bones / Q000473:pathology; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D045744:Cell Line, Tumor; D003080:Cold Temperature; D004195:Disease Models, Animal; D005528:Foot; D008113:Liver Neoplasms / Q000473:pathology; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D009361:Neoplasm Invasiveness; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000150:complications*; D010146:Pain / Q000209:etiology* / Q000503:physiopathology / Q000523:psychology*; D017288:Pain Threshold; D010812:Physical Stimulation; D013848:Thigh