title: Electroacupuncture attenuates bone cancer pain and inhibits spinal interleukin-1 beta expression in a rat model.
abstract: BACKGROUND
  Although pain affects the quality of life of cancer patients, current medical treatments are either ineffective or have side effects. In the present study we investigated the effect of electroacupuncture (EA) on cancer-induced hyperalgesia and expression of interleukin-1beta (IL-1beta), upregulation of which is related to the maintenance of persistent pain, in a rat model of bone cancer pain.
  
  
  METHODS
  Cancer was induced by injecting AT-3.1 prostate cancer cells into the tibia of male Copenhagen rats. The resulting pain was treated with 10 Hz/2 mA/0.4 ms pulse EA for 30 min daily at the equivalent of the human acupoint GB30 (Huantiao) between Days 14 and 18 after cancer cell inoculation. For sham control, EA needles were inserted into GB30 without stimulation. Thermal hyperalgesia, a decrease in paw withdrawal latency to a noxious thermal stimulus, was measured at baseline and 20 min after EA treatment. IL-1beta and its mRNA were respectively determined by immunohistochemistry and reverse transcription-polymerase chain reaction analysis.
  
  
  RESULTS
  Thermal hyperalgesia developed between Days 12 and 18 after cancer cell inoculation. EA significantly (P < 0.05) attenuated this hyperalgesia, increasing paw withdrawal latency from 7.0 +/- 0.3 s to 9.2 +/- 0.4 s, and inhibited the upregulation of IL-1beta and its mRNA compared to the sham control. Intrathecal injection of IL-1 receptor antagonist (IL-1ra, 0.1 mg/rat) also significantly inhibited cancer-induced thermal hyperalgesia.
  
  
  CONCLUSIONS
  The data suggest that EA alleviates bone cancer pain, at least in part by suppressing IL-1beta expression. The results support the clinical use of EA in the treatment of cancer pain.
authors.affiliation: Center for Integrative Medicine, School of Medicine, University of Maryland, Baltimore, Maryland 21201, USA. Rzhan001@umaryland.edu
authors.forename: Rui-Xin
authors.initials: RX
authors.lastname: Zhang
authors.forename: Aihui
authors.initials: A
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.forename: Linbo
authors.initials: L
authors.lastname: Wang
authors.forename: Ke
authors.initials: K
authors.lastname: Ren
authors.forename: Jian-Tian
authors.initials: JT
authors.lastname: Qiao
authors.forename: Brian M
authors.initials: BM
authors.lastname: Berman
authors.forename: Lixing
authors.initials: L
authors.lastname: Lao
mesh_terms: D000818:Animals; D001859:Bone Neoplasms / Q000150:complications / Q000378:metabolism* / Q000628:therapy*; D004195:Disease Models, Animal; D015671:Electroacupuncture / Q000379:methods; D005786:Gene Expression Regulation / Q000502:physiology; D053583:Interleukin-1beta / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D008297:Male; D010146:Pain / Q000209:etiology / Q000378:metabolism* / Q000517:prevention & control; D051381:Rats; D013116:Spinal Cord / Q000378:metabolism*
chemical_list: D053583:Interleukin-1beta