ABSTRACT
Objective:To explore the inhibitory mechanism of herb cake-partitioned moxibustion on tumor growth in colitis-associated colorectal cancer(CAC)based on histone lysine demethylase 4D(KDM4D). Methods:Inbred male Sprague-Dawley rats were randomly divided into a normal group,a CAC group,a herb cake-partitioned moxibustion group,and an inhibitor group.Except the normal group,rats in the other three groups were treated with azoxymethane(AOM)combined with dextran sulfate sodium(DSS)to make CAC rat models.Rats in the normal group and the CAC group did not receive interventions;rats in the herb cake-partitioned moxibustion group received moxibustion at Qihai(CV6)and bilateral Tianshu(ST25),2 cones for one point each time,once a day for 30 d with 1-day rest every week;rats in the inhibitor group received intraperitoneal injection of KDM4D inhibitor,5-chloro-8-hydroxyquinoline(5-c-8HQ),once a day for 30 d.After intervention,the general condition,colon length,tumor number and volume,and histopathological colon changes were observed.The expression of adenomatous polyposis coli(APC),axis inhibitor(Axin),cyclin D1,matrix metalloproteinase(MMP)-7 and MMP-9 mRNAs were detected by real-time quantitative polymerase chain reaction.The proliferating cell nuclear antigen(PCNA),cleaved caspase3,KDM4D,APC,and Axin proteins were detected by immunohistochemistry. Results:Compared with the normal group,the general condition was poor,the colon length was significantly shortened(P<0.01),the number and volume of colonic tumors were increased(P<0.01),the structure of glandular duct was obviously disordered with"back-to-back"and cowall phenomenon,and also high-grade adenocarcinoma formed;the protein expression levels of PCNA and KDM4D were significantly increased(P<0.01),while cleaved caspase3,APC,and Axin were significantly reduced(P<0.01);the mRNA expression levels of cyclin D1,MMP-7,and MMP-9 were significantly increased(P<0.01),while APC and Axin were significantly reduced(P<0.01)in the CAC group.Compared with the CAC group,the general condition was improved,the length of colon was significantly increased(P<0.01),the number and volume of the colonic tumors were reduced(P<0.05),and the colon tissues showed epithelial cell proliferation with enlarged and deep staining nuclei,dysplasia and inflammatory cell infiltration;the protein expression levels of PCNA and KDM4D were significantly reduced(P<0.01),while the cleaved caspase3,APC,and Axin were significantly increased(P<0.01);the mRNA expression levels of cyclin D1,MMP-7,and MMP-9 were reduced(P<0.05),while the APC and Axin were increased(P<0.05)in the colon tissues of rats in the herb cake-partitioned moxibustion group and the inhibitor group. Conclusion:Herb cake-partitioned moxibustion regulated abnormally expressed KDM4D in CAC rats,activated APC and Axin,the upstream molecules of Wnt/β-catenin pathway,inhibited abnormally activated downstream molecules of Wnt/β-catenin pathway.This may be a key mechanism of herb cake-partitioned moxibustion in inhibiting CAC tumor growth.
ABSTRACT
Objective: To observe the effects of herb-partitioned moxibustion and ginger-partitioned moxibustion on the growth of colon tumors in rats with colitis-associated colon cancer (CACC), and explore the mechanism of moxibustion intervening CACC through the purinergic receptor P2X ligand-gated ion channel 7 (P2X7R)/signal transducer and activator of transcription 3 (STAT3)/vascular endothelial growth factor (VEGF) pathway. Methods: A total of 26 male Sprague-Dawley rats were selected. According to the random number table method, 6 rats were selected as the normal group. The remaining 20 rats were injected intraperitoneally with azoxymethane (AOM) combined with oral dextran sodium sulfate (DSS) to prepare the CACC model. After the model was successfully established, 2 rats were randomly selected for model identification. The remaining 18 rats which were successfully modeled were randomly divided into a model group, a herb-partitioned moxibustion group and a ginger-partitioned moxibustion group, with 6 rats in each group. Moxibustion intervention was performed in the herb-partitioned moxibustion group and the ginger-partitioned moxibustion group at Qihai (CV 6) and bilateral Tianshu (ST 25). Moxibustion was performed twice at each point each time, once a day, at a 1-day interval after 6 consecutive interventions, for a total of 30 interventions. After intervention, the colon tumor load, pathological change and histopathological score were observed. Immunohistochemistry was used to detect the expressions of VEGF, P2X7R, phospho-STAT3 (p-STAT3), and nuclear factor-kappa B p65 (NF-κB p65) proteins in rat colon tissue. Western blot was used to detect the levels of p-STAT3 and NF-κB p65 proteins in rat colon tissue. Results: Compared with the normal group, the colon tumor load and histopathological score in the model group were significantly increased (both P<0.001), and different grades of dysplasia were observed in colon tissue from the model group, reaching the degree of adenocarcinoma; the expression level of P2X7R protein in colon tissue was significantly decreased (P<0.001), and the expression levels of p-STAT3, NF-κB p65 and VEGF proteins were significantly increased (all P<0.001) in the model group. Compared with the model group, the colon tumor load, colon histopathological score and the levels of p-STAT3, NF-κB p65 and VEGF proteins in colon tissue were significantly decreased (all P<0.05) in the herb-partitioned moxibustion group and the ginger-partitioned moxibustion group while the expression levels of P2X7R protein in colon tissue were significantly increased (both P<0.05). Conclusion: Both herb-partitioned moxibustion and ginger-partitioned moxibustion can reduce the colon tumor load in CACC rats and delay the progression of colon adenomas. The mechanism may be mediated by the P2X7R/STAT3 pathway to inhibit STAT3 phosphorylation, thereby reducing VEGF protein expression.