BRMS1 up-regulates miR-146. A, ectopic expression of BRMS1 in MDA-MB-231 or MDA-MB-435 breast cancer cell lines significantly enhanced the expression of miR-146a as shown by real-time RT-PCR (∼6-fold and ∼60-fold, respectively). miR-146b expression was also increased in MDA-MB-435 (∼40-fold). B, endogenous expression levels of miR-146a and miR-146b in multiple breast-derived cell lines generally show decreased levels in tumorigenic but weakly/nonmetastatic cell lines (MCF7, T47D, and MDA-MB-436) compared with the immortalized, nontumorigenic breast epithelial cell line (MCF10A) and a further decrease was found in metastatic MDA-MB-435. Please note scale differences.