TY - JOUR
T1 - P2X7 receptor-deficient mice are susceptible to bone cancer pain
AU - Hansen, Rikke Rie
AU - Nielsen, Christian K.
AU - Nasser, Arafat
AU - Thomsen, Stine I. M.
AU - Eghorn, Laura F
AU - Pham, Yen
AU - Schulenburg, Cecilia
AU - Syberg, Susanne
AU - Ding, Ming
AU - Stojilkovic, Stanko S
AU - Jorgensen, Niklas R
AU - Heegaard, Anne-Marie
N1 - Copyright © 2011 International Association for the Study of Pain. All rights reserved.
PY - 2011/8
Y1 - 2011/8
N2 - The purinergic P2X7 receptor is implicated in both neuropathic and inflammatory pain, and has been suggested as a possible target in pain treatment. However, the specific role of the P2X7 receptor in bone cancer pain is unknown. We demonstrated that BALB/cJ P2X7 receptor knockout (P2X7R KO) mice were susceptible to bone cancer pain and moreover had an earlier onset of pain-related behaviours compared with cancer-bearing, wild-type mice. Furthermore, acute treatment with the selective P2X7 receptor antagonist, A-438079, failed to alleviate pain-related behaviours in models of bone cancer pain with and without astrocyte activation (BALB/cJ or C3H mice inoculated with 4T1 mammary cancer cells or NCTC 2472 osteosarcoma cells, respectively), suggesting that astrocytic P2X7 receptors play a negligible role in bone cancer pain. The results support the hypothesis that bone cancer pain is a separate pain state compared with those of neuropathic and inflammatory pain. However, the recent discovery of a P2X7 receptor splice variant expressed in the knockout mice used for this study complicates the interpretation of the results. The P2X7 splice variant receptor was detected in the spinal cord but not in osteoclasts of the P2X7R KO mouse. Further experiments are needed to elucidate the exact role of the P2X7 receptors in bone cancer pain. Pain-related behaviours had an earlier onset in bone cancer-bearing, P2X7 receptor-deficient mice, and treatment with A-438079 failed to alleviate pain-related behaviours.
AB - The purinergic P2X7 receptor is implicated in both neuropathic and inflammatory pain, and has been suggested as a possible target in pain treatment. However, the specific role of the P2X7 receptor in bone cancer pain is unknown. We demonstrated that BALB/cJ P2X7 receptor knockout (P2X7R KO) mice were susceptible to bone cancer pain and moreover had an earlier onset of pain-related behaviours compared with cancer-bearing, wild-type mice. Furthermore, acute treatment with the selective P2X7 receptor antagonist, A-438079, failed to alleviate pain-related behaviours in models of bone cancer pain with and without astrocyte activation (BALB/cJ or C3H mice inoculated with 4T1 mammary cancer cells or NCTC 2472 osteosarcoma cells, respectively), suggesting that astrocytic P2X7 receptors play a negligible role in bone cancer pain. The results support the hypothesis that bone cancer pain is a separate pain state compared with those of neuropathic and inflammatory pain. However, the recent discovery of a P2X7 receptor splice variant expressed in the knockout mice used for this study complicates the interpretation of the results. The P2X7 splice variant receptor was detected in the spinal cord but not in osteoclasts of the P2X7R KO mouse. Further experiments are needed to elucidate the exact role of the P2X7 receptors in bone cancer pain. Pain-related behaviours had an earlier onset in bone cancer-bearing, P2X7 receptor-deficient mice, and treatment with A-438079 failed to alleviate pain-related behaviours.
KW - Former Faculty of Pharmaceutical Sciences
U2 - 10.1016/j.pain.2011.03.024
DO - 10.1016/j.pain.2011.03.024
M3 - Journal article
C2 - 21565445
SN - 0304-3959
VL - 152
SP - 1766
EP - 1776
JO - Pain
JF - Pain
IS - 8
ER -
