Involvement of Spinal Bv8/Prokineticin 2 in a Rat Model of Cancer-Induced Bone Pain.

Cancer-induced bone pain (CIBP) is seriously disruptive to the quality of life in cancer patients, and present therapies are limited. The Bv8/prokineticin 2, a new family of chemokines, has been demonstrated to be involved in inflammatory and neuropathic pain. However, whether it is involved in CIBP remains unclear. This study was designed to examine whether spinal Bv8 was involved in the development of CIBP in rats. A rat CIBP model was constructed by injecting Walker 256 carcinoma cells into the medullary cavity of rat tibia. Tibia inoculation with Walker 256 tumour cells resulted in the development of mechanical hyperalgesia. Compared with sham rats, spinal Bv8 mRNA and protein levels were markedly and time-dependently increased in CIBP rats. Intrathecal administration of Bv8 neutralizing antibody (5 ng) could markedly attenuate pain behaviour as well as up-regulation of spinal TNF-α expression at day 18 after inoculation. Intrathecal pre-treatment with synthetic Bv8 (50 pg) almost completely abolished these effects. These data suggested that spinal Bv8/prokineticin 2 participated in the development of CIBP. Targeting of spinal Bv8 might be a promising strategy for the management of cancer-induced bone pain.