国际肿瘤学杂志

国际肿瘤学杂志 ›› 2017, Vol. 44 ›› Issue (11): 806-811.doi: 10.3760/cma.j.issn.1673422X.2017.11.002

• 论著 • 上一篇    下一篇

熊果酸对小鼠结直肠肿瘤及微环境的作用初探

乐红红，郝文斌，相芬芬，倪振华，许军，吴蓉，康向东   

  1. 200333上海中医药大学附属普陀医院检验科（乐红红、郝文斌、相芬芬、许军、吴蓉、康向东），中心实验室（倪振华）
  • 收稿日期:2017-02-21 出版日期:2017-11-08 发布日期:2017-11-24

Primary study of the effects of ursolic acid on colorectal tumor and tumor microenvironment in mice

Yue Honghong, Hao Wenbin, Xiang Fenfen, Ni Zhenhua, Xu Jun, Wu Rong, Kang Xiangdong   

  1. Department of Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200333, China
  • Received:2017-02-21 Online:2017-11-08 Published:2017-11-24

PDF

691

摘要： 目的探讨熊果酸对小鼠结直肠肿瘤及微环境的作用及可能的作用机制，为熊果酸的临床运用提供理论依据。方法建立小鼠CT26细胞肠癌皮下移植瘤模型，将模型分为4组，即空白组、荷瘤对照组、荷瘤二甲基亚砜（DMSO）组、荷瘤熊果酸组。酶联免疫吸附试验（ELISA）检测小鼠外周血白细胞介素6（IL6）水平，流式细胞术检测小鼠脾脏骨髓来源的抑制性细胞（MDSC）的数量和百分比，实时荧光定量PCR（RTPCR）检测小鼠瘤组织IL6、信号传导与转录激活因子3（STAT3）mRNA的表达水平，Western blotting检测小鼠瘤组织STAT3、磷酸化的信号传导与转录激活因子3（pSTAT3）蛋白的水平。结果动物实验显示熊果酸可显著降低结直肠癌荷瘤小鼠脾脏MDSC的数量，荷瘤熊果酸组［（249.60±17.12）个］较荷瘤DMSO组［（366.40±34.08）个］小鼠脾脏MDSC的数量显著下降，差异具有统计学意义（P=0.021）。荷瘤熊果酸组外周血中IL6的水平［（46.40±17.05）pg/ml］显著低于荷瘤DMSO组［（94.27±21.51）pg/ml］，差异具有统计学意义（P=0.012）。荷瘤熊果酸组瘤组织中IL6、STAT3 mRNA的水平（0.12±0.01，0.21±0.08）显著低于荷瘤DMSO组（0.69±0.14，0.79±0.06），差异具有统计学意义（P=0.008；P=0.003）。荷瘤熊果酸组瘤组织中STAT3、pSTAT3蛋白的水平（0.81±0.02，0.28±0.04）显著低于荷瘤DMSO组（0.98±0.02，0.91±0.22），差异具有统计学意义（P=0.027；P=0.029）。结论熊果酸可能通过降低IL6水平抑制肿瘤组织中STAT3信号通路的激活及MDSC在微环境中的扩增，从而增强机体免疫杀伤肿瘤细胞的作用，进而调控肿瘤免疫微环境，抑制小鼠肠癌细胞免疫逃逸。

关键词: 熊果酸, 结直肠肿瘤, 肿瘤微环境, 骨髓来源的抑制性细胞

Abstract: ObjectiveTo investigate the effect of ursolic acid (UA) on the colorectal tumor and microenvironment in mice, and to provide a theoretical basis for the clinical application of UA. MethodsThe models of subcutaneous transplanted tumor of mouse CT26 cells was established. The models were divided into four groups: control group, tumor bearing group, tumor bearing dimethyl sulfoxide (DMSO) group and tumor bearing UA group. The serum levels of interleukin6 (IL6) were detected by enzyme linked immunosorbent assay (ELISA). The number and percentage of myeloidderived suppressor cell (MDSC) in the spleen of mice were analyzed by flow cytometry. The mRNA levels of IL6 and signal transducer and activator of transcription 3 (STAT3) in tumor were examined by realtime quantitative polymerase chain reaction (RTPCR). The protein levels of STAT3 and pSTAT3 in tumor were detected by Western blotting. ResultsThe results showed that UA could significantly decrease the number of spleen MDSC. The accounts of spleen MDSC of tumor bearing UA group (249.60±17.12) was lower than that of tumor bearing DMSO group (366.40±34.08), and the difference was statistically significant (P=0.021). The serum level of IL6 in tumor bearing UA group ［(46.40±17.05) pg/ml］ was decreased than that in tumor bearing DMSO group ［(94.27±21.51) pg/ml］, and the difference was statistically significant (P=0.012). The expression levels of IL6 and STAT3 mRNA in tumor tissues of tumor bearing UA group (0.12±0.01, 0.21±0.08) were lower than those of tumor bearing DMSO group (0.69±0.14, 0.79±0.06), and the differences were statistically significant (P=0.008; P=0.003). The protein expression levels of STAT3 and pSTAT3 in tumor tissues of tumor bearing UA group (0.81±0.02, 0.28±0.04) were lower than those of tumor bearing DMSO group (0.98±0.02, 0.91±0.22), and the differences were statistically significant (P=0.027; P=0.029) . ConclusionUA may inhibit the activation of STAT3 signaling pathway and the amplification of MDSC in microenvironment by reducing IL6, thus to enhance the function of immunekilling tumor cells to regulate tumor immune microenvironment and inhibit the immune escape of mouse colorectal cancer cells.

Key words: Ursolic acid, Colorectal neoplasms, Tumor microenvironment, Myeloidderived suppressor cells