OBJECTIVE: To investigate the impact of combined treatment of colorectal cancer (CRC) with electroacupuncture (EA) and capeOX (combined administration of fluorouracil, oxaliplatin and capecitabine) on the tumor volume, weight, spleen coefficient, apoptosis and ferroptosis of tumor tissue, and liver and kidney functions in nude mice with CRC, so as to explore its mechanisms underlying inhibiting CRC and alleviating toxic reactions of capeOX.
METHODS: Female Balb/c nude mice were randomly assigned to 3 groups:model, capeOX, and EA+capeOX, with 8 nude mice in each group. The CRC model was established by subcutaneous injection of colon cancer cells at the right inguinal region. Nude mice of the capeOX group received intraperitoneal injection of oxaliplatin for 1 day and gavage of capecitabine from day 2 to day 7. EA (1 mA, 2 Hz/100 Hz) was applied to bilateral \"Zusanli\" (ST36) for 20 min, once daily for 7 days. During the interven-tion, the tumor volume and weight were measured every day, and at the end of intervention, the weight of the tumor tissue and spleen were measured, with tumor volume difference and spleen coefficient calculated. The proportion of apoptotic cells was measured by flow cytometry, and the contents of serum malondialdehyde (MDA), alanine aninotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), and creatinine (Cr) were detected using ELISA. The expression level of glutathione peroxidase 4 (GPX4, a key regulator for ferroptosis) protein of the tumor tissue was determined using Western blot.
RESULTS: Compared to the model group, both the capeOX group and EA+capeOX group showed a decrease in the tumor volume (on day 3 and 4 in the capeOX group, and from day 2 to 7 in the EA+capeOX group) and body weight (P<0.05, on day 3 to 7 in the EA+capeOX group and on day 2 to 7 in the capeOX group), being evidently lower in the tumor volume on day 7 in the EA+capeOX than in the capeOX group (P<0.05), and evidently higher in the body weight on day 6 and 7 in the EA+capeOX group than in the capeOX group (P<0.05). In comparison with the model group, the tumor volume difference, tumor weight and spleen coefficient in both capeOX and EA+capeOX groups were significantly decreased (P<0.05), and MDA content in EA+capeOX group was significantly decreased (P<0.05), while the contents of ALT, BUN and Cr in the capeOX group, the proportion of apoptotic cells in both capeOX and EA+capeOX groups, and the GPX4 expression level in the EA+capeOX group were all significantly increased (P<0.05). The tumor volume difference, tumor weight, and contents of MDA, ALT, AST, BUN and Cr in the EA+capeOX group were markedly lower than in the capeOX group (P<0.05), while the spleen coefficient, proportion of apoptotic cells and GPX4 expression level in the EA+capeOX group were markedly higher than those in the capeOX group (P<0.05).
CONCLUSIONS: EA of ST36 can enhance the effect of capeOX in inhibiting colorectal cancer growth in nude mice with CRC, which may be related with its functions in promoting tumor cell apoptosis, inhibiting ferroptosis, and modulating immune tolerance. In addition, EA can lower the side effects of capeOX in hematopoietic and immune, liver, and kidney functions.
目的: 观察电针“足三里”联合capeOX方案对结直肠癌(CRC)裸鼠肿瘤体积、肿瘤质量、脾脏系数、肿瘤细胞凋亡、铁死亡及肝肾功能的影响,探讨电针辅助capeOX抑制CRC、减轻capeOX毒性反应的作用机制。方法: 将雌性Balb/c裸鼠随机分为模型组、capeOX组、电针(EA)+capeOX组,每组8只。采用右侧腹股沟皮下注射结肠癌细胞复制CRC模型。CapeOX组于造模成功后第1天给予腹腔注射奥沙利铂,第2~7天按100 mg/kg给予卡培他滨灌胃;EA+capeOX组在capeOX组的基础上每天给予电针双侧“足三里”,1 mA,2 Hz/100 Hz,20 min/次,1次/d,共干预7 d。干预期间每天测量肿瘤体积、裸鼠体质量,干预结束后称量肿瘤及脾脏质量,计算肿瘤体积差和脾脏系数,流式细胞仪检测肿瘤组织的凋亡细胞比例,ELISA法检测血清丙二醛(MDA)、谷丙转氨酶(ALT)、谷草转氨酶(AST)、尿素氮(BUN)及肌酐(Cr)的含量,Western blot法检测肿瘤组织谷胱甘肽过氧化酶4(GPX4)蛋白表达水平。结果: 与模型组比较,capeOX组、EA+capeOX组裸鼠肿瘤体积、体质量、肿瘤体积差、肿瘤质量及脾脏系数均降低(P<0.05),肿瘤组织中的凋亡细胞比例上升(P<0.05);capeOX组ALT、BUN及Cr含量均上升(P<0.05);EA+capeOX组血清MDA含量降低(P<0.05),GPX4蛋白表达水平升高(P<0.05)。与capeOX组比较,EA+capeOX组的肿瘤体积、肿瘤体积差、肿瘤质量及MDA、ALT、AST、BUN、Cr含量均降低(P<0.05),体质量、脾脏系数、凋亡细胞比例、GPX4蛋白表达水平均升高(P<0.05)。结论: 电针“足三里”可增强capeOX抑制CRC的疗效,其作用机制可能与促进肿瘤细胞凋亡、抑制铁死亡、调节免疫耐受有关;另外,电针“足三里”联合capeOX还可减轻capeOX对造血功能、免疫功能、肝肾功能的损害。.