Intrathecal Injection Of Dznep Relieves Bone Cancer Pain In Rats

Objective:This study aims to investigate the role of EZH2 in the spinal cord of rats with bone cancer pain(BCP),and to investigate whether intrathecal injection of 3-Deazaneplanocin A(DZNep)alleviates bone cancer pain in rats.Methods:Female SD rats of the same age weighing about 160g were selected for the experiment.The experiment is divided into 3 parts:The first part is randomly dividing the SD rats into Normal(N)group,sham operation(sham)group,and BCP group.Injecting the Walker 256 breast cancer cells(about 1×10~5)into the left tibia bone cavity of SD rats to establish the rat bone cancer pain model.Measuring the ambulatory score(AS)and paw withdraw threshold(PWT)of the three groups of rats before modeling(0 d)and 1,3,6,9,12,15 d after modeling.The bone destruction of rats was observed by X-ray photography.The second part is to measure the spinal expression of EZH2m RNA,protein and the 27th lysine trimethyl transferase of histone H3(H3K27TM)at0,6,9 and 12 days in the three groups using real-time fluorescent quantitative PCR(RT-q PCR)and Western blotting(WB).The third part is randomly dividing the SD rats into N group,BCP group,BCP+saline group,and BCP+DZNep group.Injecting an EXH2 inhibitor into the sheath 3,4,and 5 days after modeling,each with a volume of10μL,once daily,in the BCP+saline group and BCP+DZNep group.The changes in AS scores and PWT of each group at 0,1,3,6,9,12,and 15 days were observed,and the changes in the expression of EZH2 protein in the spinal cord tissues of the four groups of rats on 9 days were measured by WB.Results:Compared with the N group and the sham group,the AS scores of the rats in the BCP group increased gradually 6-15 days after modeling,and the PWT decreased continuously(P<0.01);the left tibia X-ray film showed that the bone density of the BCP rats gradually decreased and the trabeculae defect occurred 6 days after modeling,and the bone damage continued to aggravate over time.RT-q PCR and WB results showed that compared with the N group and the sham group,the expression levels of EZH2 m RNA and protein,H3K27Tm protein in the spinal cord tissue of BCP rats at 6,9,and 12 days were significantly up-regulated(P<0.05),the expression level of EZH2m RNA was the highest on the 6th day,and both EZH2 and H3K27Tm protein expressed the highest on the 9th day(P<0.05).Compared with the BCP group,the AS score of the rats in the BCP+DZNep group was significantly lower than that of the BCP group within 6-15 days(P<0.05),but still higher than that of the N group(P<0.01);PWT was significantly higher than that of the BCP group(P<0.01),but still lower than the N group(P<0.01).The expression of EZH2 in spinal cord tissue of rats in the BCP+DZNep group was significantly lower than that in the BCP group at 9 days(P<0.05),but it was still significantly higher than that in the N group(P<0.05).Conclusion:Intrathecal injection of DZNep can relieve the pain of bone cancer in rats.EZH2 in spinal cord tissue may be involved in the process of bone cancer pain in rats.