Ramazan Rezaei1, Kaveh Baghaei2, Davar Amani3, Andrea Piccin4, Seyed Mahmoud Hashemi1, Hamid Asadzadeh Aghdaei5, Mohammad Reza Zali6. 1. Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 2. Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: kavehbaghaei@sbmu.ac.ir. 3. Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: amanid@sbmu.ac.ir. 4. Haematology Dept, Our Lady's Children's Hospital, Dublin, Ireland; Dept of Internal Medicine V, University of Innsbruck, Innsbruck, Austria. 5. Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 6. Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Abstract
AIMS: EMT is the process by which a polarized epithelial cell undergoes several changes leading to highly invasive and fibroblast-like morphology. It has been described that miR-375 is inversely associated with EMT in cancerous patients and can effectively inhibit invasion and migration of tumor cells. Here, we investigate whether miR-375 mimic delivered by tumor-derived exosomes could reverse EMT process. MAIN METHODS: The exosomes were isolated from HT-29 and SW480. Subsequently, exosomes were loaded with miR-375-3p mimic applying modified calcium chloride method. Quantitative real-time PCR was used for evaluation of the loading efficiency of miR-375 mimic in the exosomes. The effects of miR-375 loaded tumor exosomes (TEXomiR) on EMT process investigated using flow cytometry, cell morphology, and invasion and migration assay. KEY FINDINGS: The in vitro results showed that the tumor derived exosomes can efficiently deliver miR-375 mimic to reduce the expression of β-catenin, vimentin, ZEB1, and snail. In contrast, TEXomiR significantly increased the expression of E- cadherin in EMT process. Furthermore, the migration and invasion abilities of HT-29 and SW480 cells were inhibited by TEXomiR. The expression of CD44 and CD133 are increased in EMT process. Flow cytometry evaluation demonstrated that treatment with TEXomiR significantly decreased the expression of CD44 and CD133 in SW480 cell line. SIGNIFICANCE: Our results imply that colon cancer cells-derived exosomes could be used as an effective nonvehicle to deliver miR-375-3p mimic. Moreover, TEXomiR may be a potent therapeutic agent for the treatment of metastatic colorectal cancer.
AIMS: EMT is the process by which a polarized epithelial cell undergoes several changes leading to highly invasive and fibroblast-like morphology. It has been described that miR-375 is inversely associated with EMT in cancerouspatients and can effectively inhibit invasion and migration of tumor cells. Here, we investigate whether miR-375 mimic delivered by tumor-derived exosomes could reverse EMT process. MAIN METHODS: The exosomes were isolated from HT-29 and SW480. Subsequently, exosomes were loaded with miR-375-3p mimic applying modified calcium chloride method. Quantitative real-time PCR was used for evaluation of the loading efficiency of miR-375 mimic in the exosomes. The effects of miR-375 loaded tumor exosomes (TEXomiR) on EMT process investigated using flow cytometry, cell morphology, and invasion and migration assay. KEY FINDINGS: The in vitro results showed that the tumor derived exosomes can efficiently deliver miR-375 mimic to reduce the expression of β-catenin, vimentin, ZEB1, and snail. In contrast, TEXomiR significantly increased the expression of E- cadherin in EMT process. Furthermore, the migration and invasion abilities of HT-29 and SW480 cells were inhibited by TEXomiR. The expression of CD44 and CD133 are increased in EMT process. Flow cytometry evaluation demonstrated that treatment with TEXomiR significantly decreased the expression of CD44 and CD133 in SW480 cell line. SIGNIFICANCE: Our results imply that colon cancer cells-derived exosomes could be used as an effective nonvehicle to deliver miR-375-3p mimic. Moreover, TEXomiR may be a potent therapeutic agent for the treatment of metastatic colorectal cancer.