Guoying Jin1,2, Yuhang Liu1,2, Jia Zhang1,2, Zehua Bian1,2, Surui Yao1,2, Bojian Fei3, Leyuan Zhou4, Yuan Yin5,6, Zhaohui Huang7,8. 1. Wuxi Cancer Institute, Affiliated Hospital of Jiangnan University, 200 Huihe Road, Wuxi, 214062, Jiangsu, China. 2. Cancer Epigenetics Program, Wuxi School of Medicine, Jiangnan University, Wuxi, 214122, Jiangsu, China. 3. Department of Surgical Oncology, Affiliated Hospital of Jiangnan University, Wuxi, 214062, Jiangsu, China. 4. Department of Radiation Oncology, The Affiliated Hospital of Jiangnan University, Wuxi, 214062, China. 5. Wuxi Cancer Institute, Affiliated Hospital of Jiangnan University, 200 Huihe Road, Wuxi, 214062, Jiangsu, China. yinyuandiana@163.com. 6. Cancer Epigenetics Program, Wuxi School of Medicine, Jiangnan University, Wuxi, 214122, Jiangsu, China. yinyuandiana@163.com. 7. Wuxi Cancer Institute, Affiliated Hospital of Jiangnan University, 200 Huihe Road, Wuxi, 214062, Jiangsu, China. hzhwxsy@126.com. 8. Cancer Epigenetics Program, Wuxi School of Medicine, Jiangnan University, Wuxi, 214122, Jiangsu, China. hzhwxsy@126.com.
Abstract
BACKGROUND: Chemoresistance is a common problem for cancer treatment worldwide. Circulating exosomal microRNAs (miRNAs) have been considered as promising biomarkers of cancers. However, few studies have assessed the relationship between serum/plasma exosomal microRNAs and chemoresistance in colorectal cancer (CRC). METHODS: Based on previous microarray analysis, we selected 30 miRNAs which are aberrantly expressed during CRC progression and then detected their expression levels in three pairs of oxaliplatin/5-fluorouracil-resistant CRC cell lines and the corresponding secreted exosomes. Six candidate exosomal miRNAs were identified for further evaluating potential value in predicting chemotherapeutic effect in advanced CRC patients. Finally, the molecular mechanisms of these miRNAs in drug resistance were explored by bioinformatics preliminarily. RESULTS: We observed that the expression of 14 miRNAs was significantly higher in three drug-resistant CRC cells comparing with their parental cells. Among these miRNAs, miR-21-5p, miR-1246, miR-1229-5p, miR-135b, miR-425 and miR-96-5p are also up-regulated in exosomes from culture media of resistant cells. Clinical sample analysis confirmed that the expression levels of miR-21-5p, miR-1246, miR-1229-5p and miR-96-5p in serum exosomes were significantly higher in chemoresistant patients in contrast with chemosensitive controls. ROC curve showed that the combination of the four miRNAs had an area of under the curve (AUC) of 0.804 (P < 0.05). In addition, GO analysis and KEGG pathway analysis revealed that these miRNAs were enriched in PI3K-Akt signaling pathway, FoxO signaling pathway and autophagy pathway. CONCLUSIONS: Our study demonstrates that a panel of serum exosomal miRNAs containing miR-21-5p, miR-1246, miR-1229-5p and miR-96-5p could significantly distinguish the chemotherapy-resistant group from advanced colorectal cancer patients. Targeting these miRNAs may promote chemosensitivity to oxaliplatin and 5-fluorouracil, and might be promising strategy for CRC treatment.
BACKGROUND: Chemoresistance is a common problem for cancer treatment worldwide. Circulating exosomal microRNAs (miRNAs) have been considered as promising biomarkers of cancers. However, few studies have assessed the relationship between serum/plasma exosomal microRNAs and chemoresistance in colorectal cancer (CRC). METHODS: Based on previous microarray analysis, we selected 30 miRNAs which are aberrantly expressed during CRC progression and then detected their expression levels in three pairs of oxaliplatin/5-fluorouracil-resistant CRC cell lines and the corresponding secreted exosomes. Six candidate exosomal miRNAs were identified for further evaluating potential value in predicting chemotherapeutic effect in advanced CRC patients. Finally, the molecular mechanisms of these miRNAs in drug resistance were explored by bioinformatics preliminarily. RESULTS: We observed that the expression of 14 miRNAs was significantly higher in three drug-resistant CRC cells comparing with their parental cells. Among these miRNAs, miR-21-5p, miR-1246, miR-1229-5p, miR-135b, miR-425 and miR-96-5p are also up-regulated in exosomes from culture media of resistant cells. Clinical sample analysis confirmed that the expression levels of miR-21-5p, miR-1246, miR-1229-5p and miR-96-5p in serum exosomes were significantly higher in chemoresistant patients in contrast with chemosensitive controls. ROC curve showed that the combination of the four miRNAs had an area of under the curve (AUC) of 0.804 (P < 0.05). In addition, GO analysis and KEGG pathway analysis revealed that these miRNAs were enriched in PI3K-Akt signaling pathway, FoxO signaling pathway and autophagy pathway. CONCLUSIONS: Our study demonstrates that a panel of serum exosomal miRNAs containing miR-21-5p, miR-1246, miR-1229-5p and miR-96-5p could significantly distinguish the chemotherapy-resistant group from advanced colorectal cancerpatients. Targeting these miRNAs may promote chemosensitivity to oxaliplatin and 5-fluorouracil, and might be promising strategy for CRC treatment.