Shan-Shan Yang1, Shuang Ma2, He Dou2, Feng Liu2, Shi-Yuan Zhang2, Cong Jiang2, Min Xiao3, Yuan-Xi Huang4. 1. Department of Gynecological Radiotherapy, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, 150081, PR China. 2. Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, 150081, PR China. 3. Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, 150081, PR China. Electronic address: xiaomin@hrbmu.edu.cn. 4. Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang, 150081, PR China. Electronic address: doctor_hyx@126.com.
Abstract
OBJECTIVE: To explore the effects of breast cancer (BC)-derived exosomes on invasion and migration of BC cells. METHODS: Exosomes (Exo-MA, Exo-M7, Exo-M1) were extracted from normal breast epithelial cells (MCF-10A), BC cells (MCF-7/MDA-MB-231) and BC cells with miR-146a overexpression or knockdown using multi-step differential centrifugation. Morphologies and sizes of exosomes were observed by transmission electron microscope (TEM) and particle size analysis respectively. BC mouse models were injected with DIR labeled Exo-MA, Exo-M7 or Exo-M1. The epithelial-mesenchymal transition (EMT) in BC cells was determined by PCR and Western blot. PKH67 labeled Exo-MA, Exo-M7 and Exo-M1 were incubated with NFs or MCF-7 to measure the activation of CAFs. Cell invasion and migration abilities were determined by scratch test and Transwell assay. RESULTS: Exo-MA, Exo-M7, Exo-M1 were successfully extracted with positive expressions of Alix, CD63 and TSG101. Contents of Ki67, N-cadherin, Vimentin and Snail-1 were increased but E-cadherin was decreased, compared to Exo-MA group. Exo-M7 or Exo-M1 could increase BC cell proliferation and enhance EMT in nude mouse. Exo-M7 and Exo-M1 could accelerate the transformation of NFs into CAFs and promote the recruitment of CAFs in MCF-7. Transfection of miR-146a could promote the transformation of NFs into CAFs and promote cell invasion and migration of MCF-7 cells. As a target gene of miR-146a, TXNIP could inhibit the activation of CAFs. miR-146a overexpression or TXNIP silence enhance the activation of Wnt signal pathway. CONCLUSION: BC-derived exosomes promote the activation of CAFs through miR-146a/TXNIP axis to activate Wnt pathway, which in turn enhances invasion and metastasis of BC cells.
OBJECTIVE: To explore the effects of breast cancer (BC)-derived exosomes on invasion and migration of BC cells. METHODS: Exosomes (Exo-MA, Exo-M7, Exo-M1) were extracted from normal breast epithelial cells (MCF-10A), BC cells (MCF-7/MDA-MB-231) and BC cells with miR-146a overexpression or knockdown using multi-step differential centrifugation. Morphologies and sizes of exosomes were observed by transmission electron microscope (TEM) and particle size analysis respectively. BCmouse models were injected with DIR labeled Exo-MA, Exo-M7 or Exo-M1. The epithelial-mesenchymal transition (EMT) in BC cells was determined by PCR and Western blot. PKH67 labeled Exo-MA, Exo-M7 and Exo-M1 were incubated with NFs or MCF-7 to measure the activation of CAFs. Cell invasion and migration abilities were determined by scratch test and Transwell assay. RESULTS:Exo-MA, Exo-M7, Exo-M1 were successfully extracted with positive expressions of Alix, CD63 and TSG101. Contents of Ki67, N-cadherin, Vimentin and Snail-1 were increased but E-cadherin was decreased, compared to Exo-MA group. Exo-M7 or Exo-M1 could increase BC cell proliferation and enhance EMT in nude mouse. Exo-M7 and Exo-M1 could accelerate the transformation of NFs into CAFs and promote the recruitment of CAFs in MCF-7. Transfection of miR-146a could promote the transformation of NFs into CAFs and promote cell invasion and migration of MCF-7 cells. As a target gene of miR-146a, TXNIP could inhibit the activation of CAFs. miR-146a overexpression or TXNIP silence enhance the activation of Wnt signal pathway. CONCLUSION:BC-derived exosomes promote the activation of CAFs through miR-146a/TXNIP axis to activate Wnt pathway, which in turn enhances invasion and metastasis of BC cells.