[Electroacupuncture postpones growth of tumors by activating SIRT1 expression to reduce inflammatory reaction and facilitate cellular autophagy in mice with transformed colorectal carcinomas].

ABSTRACT

OBJECTIVE: To observe the effect of electroacupuncture (EA) on tumor number, body conditions, inflammatory factors and expression levels of silent information regulator 1 (sirtuin 1, SIRT1) and autophagy-related proteins Beclin-1, P62, and LC3 in colorectal tissues in inflammatory-transformed colorectal cancer mice, so as to explore its underlying mechanisms in resisting tumor growth. METHODS: A total of 100 C57BL/6 male mice were randomly divided into normal control, model, EA, EA + SIRT1 inhibitor (EA+inhibitor) and agonist resveratrol (agonist) groups, with 20 mice in each group. EA (2 Hz, 1 mA) was applied to "Zusanli"(ST36)and "Fenglong"(ST40) for 20 min every time, 3 times a week for 11 weeks. Mice of the EA +inhibitor group received intraperitoneal injection of SIRT1 inhibitor EX527 (5 mg/kg) at the same time of EA treatment, and those of the agonist group received gavage of resveratrol (200 mg/kg, an agonist of SIRT1), 3 times a week for 11 weeks. The body mass was measured weekly. The disease activity index (DAI), colorectal length and tumor number in each group were recorded. The histopathological changes of colorectal tissues were observed by H.E. staining; the contents of interleukin 6 (IL-6), IL-10, IL-17, in the colorectal tissues were detected by enzyme-linked immunosorbent assay, and the expression levels of SITR1, Beclin-1, P62, and LC3 in colorectal tissues were detected by Western blot and real-time fluorescence quantitative PCR, respectively. RESULTS: Compared with the normal control group, the body weight, length of colorectum, the contents of IL-10, and the expression levels of SIRT1,Beclin-1 and LC3 mRNAs and proteins were significantly decreased (P<0.001), whereas the DAI score, the number of tumors, the contents of IL-6 and IL-17, and the expression levels of P62 mRNA and protein were significantly increased (P<0.000 1, P<0.001) in the model group. In comparison with the model group, the body weight, the length of colorectum, the contents of IL-10, and the expression levels of SIRT1,Beclin-1 and LC3 mRNAs and proteins were significantly increased (P<0.01,P<0.05,P<0.001), while the DAI scores, the numbers of tumors, the contents of IL-6 and IL-17, and the expression levels of P62 mRNA and protein were obviously decreased in the EA and agonist groups (P<0.01,P<0.05, P<0.001). No significant changes were found in all the above-mentioned indexes in the EA+inhibitor group in comparison with the model group (P>0.05). CONCLUSION: EA can reduce the number of tumors and inflammation reaction in colorectal tissue and improve the body condition in mice with colorectal cancer, which may be related to its functions in activating the expression of intestinal SIRT1, and then facilitating cellular autophagy.