Bone cancer pain is difficult to treat and has a strong impact on the quality of life of patients. Few
therapies have emerged because the molecular mechanisms underlying
bone cancer pain are poorly understood. Recently, T-cell death-associated gene 8 (TDAG8) has been shown to participate in complete
Freund's adjuvant-induced chronic inflammatory
pain. In this study, we aimed to examine whether TDAG8 and its downstream
protein kinase A (PKA) pathway are involved in
bone cancer pain. A
bone cancer pain model was made by inoculation of Walker 256 cells into the intramedullary space of rat tibia. Spinal TDAG8 expression was increased after inoculation with
tumor cells. Intrathecal TDAG8
siRNA attenuated
bone cancer pain behaviors during the initiation and maintenance phases; there were also concomitant decreases in TDAG8
mRNA and
protein levels in spinal cord. Moreover, we found spinal PKA and phosphorylated cAMP response element-binding (pCREB)
protein levels were up-regulated in the rat model of
bone cancer pain. Knockdown of TDAG8 resulted in reduced
bone cancer pain-induced spinal PKA and pCREB
protein expression in two procedures. Furthermore, intrathecal
H-89 (a
PKA inhibitor) significantly attenuated
bone cancer pain behaviors in rats. Our results suggest a causal relationship between TDAG8 expression and the initiation and maintenance of
bone cancer pain. Activation of spinal TDAG8 contributes to
bone cancer pain through the PKA signaling pathway in rats. These findings may lead to novel strategies for the treatment of
bone cancer pain.