title: MicroRNA-93-5p may participate in the formation of morphine tolerance in bone cancer pain mouse model by targeting Smad5.
abstract: In this study, we aim to find out the role of microRNA-93-5p (miR-93) and Smad5 in morphine tolerance in mouse models of bone cancer pain (BCP).
  
  
  
  At 7 days after injection of morphine, the PMWT showed no significant difference between the morphine model group and the saline model group (P < 0.05), suggesting that morphine tolerance had formed in the morphine model group. The morphine model group had higher miR-93 expression and lower Smad5 mRNA expression than the saline model group. Smad5 is a downstream target gene of miR-93. At 7, 9 and 14 days after injection of lentiviruses, the L/anti-miR-93 group had the lowest PMWTs, while the Smad5 shRNA group presented the highest PMWTs among these five groups (all P < 0.05).
  
  
  
  We built mouse models of BCP and morphine tolerance and recorded 50% PMWT. After 6 days of modeling, we set saline control group, morphine control, saline model group and morphine model group (morphine tolerance emerged). We performed luciferase reporter gene assay to verify the relation between miR-93 and Smad5. After lentivirus transfection, the mice with morphine tolerance were assigned into L/anti-miR-93 group, Smad5 shRNA group, L/anti-miR-93 + Smad5 shRNA group, blank group and PBS control group. RT-qPCR, Western Blot assay and immumohistochemical staining were performed to observe the changes of miR-93 and Smad5.
  
  
  
  Up-regulation of miR-93 may contribute to the progression of morphine tolerance by targeting Smad5 in mouse model of BCP.
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha 410008, China.
authors.forename: Wen-Feng
authors.initials: WF
authors.lastname: Xiao
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha 410008, China.
authors.forename: Yu-Sheng
authors.initials: YS
authors.lastname: Li
authors.affiliation: Department of Pain Treatment, Ningbo No.2 Hospital, Ningbo 315010, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Lou
authors.affiliation: Department of Emergency Internal Medicine, Ningbo No.2 Hospital, Ningbo 315010, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Cai
authors.affiliation: Stem Cell Laboratory, Ningbo No.2 Hospital, Ningbo 315010, China.
authors.forename: Shun
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Nephropathy Dialysis Center, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
authors.forename: Xiao-Ying
authors.initials: XY
authors.lastname: Hu
authors.affiliation: Division of Pharmaceutics, College of Pharmacy, Jinan Unversity, Guangzhou 510632, P.R. China.
authors.forename: Xing-Wang
authors.initials: XW
authors.lastname: Zhang
authors.affiliation: Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha 410008, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D001859:Bone Neoplasms / Q000150:complications* / Q000556:secondary; D000072716:Cancer Pain / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism; D018827:Carcinoma, Lewis Lung / Q000556:secondary; D004361:Drug Tolerance / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000235:genetics*; D009020:Morphine / Q000494:pharmacology; D051902:Smad5 Protein / Q000378:metabolism*
chemical_list: D000701:Analgesics, Opioid; D035683:MicroRNAs; C551470:Mirn93 microRNA, mouse; D051902:Smad5 Protein; C497798:Smad5 protein, mouse; D009020:Morphine
keywords: Smad5; bone cancer pain; microRNA-93-5p; morphine tolerance; paw mechanical withdrawal threshold