1. Islamic Azad University, Damghan Brach, Damghan 2. Department of Stem Cells and Regenerative Medicine, National Institute of Genetic Engineering and Biotechnology 3. Department of Stem Cells and Regenerative Medicine, Institute for Medical Biotechnology, National Institute of Genetic E
Abstract
Introduction
Breast cancer (bc) is the most frequent type of cancer and a main cause of cancer-related deaths among women worldwide. micrornas play pivotal roles in tumor metastasis. several studies have demonstrated decreased expression of mir-16 and mir-34a in breast tumor progression, and therefore they have been indicated as tumor suppressors in different types of cancers. due to some functional similarities between mir-16 and mir-34a we aimed to investigate whether exogenous induction of mir-34a and mir-16 can cooperate in inhibition of migration and invasion in human breast cancer cells.
Methods
Mda-mb-231 and sk-br-3 human breast cancer cell lines were cultured and transfected twice with synthetic hsa-mir-16 and hsa-mir-34a mimics individually or in combination during a 7-day culture period. at the 7th day post-transfection, the assessment of invasiveness and migratory potential of the transfected cells was performed using 3d-spheroid assay and wound healing assay, respectively. also expression of several invasion and emt markers was evaluated at gene and protein levels by quantitative real-time pcr and western blot analysis, respectively.
Results
Either mir-16 or mir-34a inhibited migration significantly. however, using both mirnas for transfection caused a greater impact on the migration rate of sk-br-3 cells compared to when using them individually. transfection of either mir-16 or mir-34a inhibited invasion in the both cell lines. expression of vimentin, beta-catenin and mapk3 in mda-mb-231 cells, and beta-catenin in sk-br-3 cells was significantly downregulated by either mir-34a or mir-16+mir-34a treatment.
Conclusion
Using both mir-16 and mir-34a can be more effective in suppression of the migratory potential of breast cancer cells. since it has been shown that mir-16 and mir-34a are either deleted or down-regulated in breast tumors, simultaneous application of these mirnas may potentiate their therapeutic impact.
Keywords
Mir-16, mir-34a, breast cancer, migration, invasion
