Han Li1, Xin Xing2, Xi Zhang2, Liping Li2, Zhenzhou Jiang3, Tao Wang3, Xin Huang2, Xinzhi Wang3, Luyong Zhang4, Lixin Sun5. 1. Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009, China; School of Food and Bioengineering, Shaanxi University of Science & Technology, Xi'an 710021, China. 2. Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009, China. 3. Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance (China Pharmaceutical University), Nanjing 210009, China. 4. Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance (China Pharmaceutical University), Nanjing 210009, China; Center for Drug Research and Development, Guangdong Pharmaceutical University, Guangzhou 510006, China. Electronic address: lyzhang@cpu.edu.cn. 5. Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing 210009, China; Key Laboratory of Drug Quality Control and Pharmacovigilance (China Pharmaceutical University), Nanjing 210009, China; Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China. Electronic address: slxcpu@126.com.
Abstract
BACKGROUNDS: Triptolide (TP) exhibits effective activity against colon cancer in multiple preclinical models, but the mechanisms underlying the observed effects are not fully understood. Sphingosine-1-phosphate (S1P) is a potent bioactive sphingolipid involved in the regulation of colon cancer progression. The aim of this study was to investigate the effect of TP on the sphingosine kinase (SPHK)-S1P signaling pathway in colitis-associated colon cancer. METHODS: An azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model and the THP-1 cell line were used to evaluate the therapeutic effects and mechanisms of TP in colitis-associated colon cancer (CACC). Various molecular cell biology experiments, including Western blotting, real-time PCR and immunofluorescence, were used to obtain relevant experimental data. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was also established to detect the levels of S1P in tissue and plasma. RESULTS: In the AOM/DSS mouse model, TP treatment induced a dose-dependent decrease in tumor incidence and inhibited macrophage recruitment and M2 polarization in the tumors. TP also efficiently decreased the S1P levels and SPHK1/S1PR1/S1PR2 expression and significantly inhibited activation of the S1P-mediated phosphorylation of ERK protein in macrophages. CONCLUSIONS: The results indicated that TP might influence the recruitment and polarization of tumor-associated macrophages by suppressing the SPHK-S1P signaling pathway.
BACKGROUNDS: Triptolide (TP) exhibits effective activity against colon cancer in multiple preclinical models, but the mechanisms underlying the observed effects are not fully understood. Sphingosine-1-phosphate (S1P) is a potent bioactive sphingolipid involved in the regulation of colon cancer progression. The aim of this study was to investigate the effect of TP on the sphingosine kinase (SPHK)-S1P signaling pathway in colitis-associated colon cancer. METHODS: An azoxymethane (AOM)/dextran sulfate sodium (DSS) mouse model and the THP-1 cell line were used to evaluate the therapeutic effects and mechanisms of TP in colitis-associated colon cancer (CACC). Various molecular cell biology experiments, including Western blotting, real-time PCR and immunofluorescence, were used to obtain relevant experimental data. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was also established to detect the levels of S1P in tissue and plasma. RESULTS: In the AOM/DSSmouse model, TP treatment induced a dose-dependent decrease in tumor incidence and inhibited macrophage recruitment and M2 polarization in the tumors. TP also efficiently decreased the S1P levels and SPHK1/S1PR1/S1PR2 expression and significantly inhibited activation of the S1P-mediated phosphorylation of ERK protein in macrophages. CONCLUSIONS: The results indicated that TP might influence the recruitment and polarization of tumor-associated macrophages by suppressing the SPHK-S1P signaling pathway.