Abstract 496: The synergistic role of miR-150-5p and miR-661 in regulating epithelial mesenchymal transition in triple negative breast cancer
Authors: Ozawa Patricia MM , Sugita Bruna M. , Fonseca Aline S. , Rodriguez Yara , Gusev Yuriy , Fadda Paolo , Kumar Deepak , Cavalli Luciane R. 
Published: August 2018

MiRNA dysregulation has been linked to cancer initiation and progression, through their control in multiple cancer associated signaling pathways. MiRNA low specificity of target interaction confer them the ability to cooperatively regulate a single biological process. Epithelial mesenchymal transition (EMT) plays pivotal roles in cancer progression and metastasis, through the regulation of transcription factors and proteins, such as E-cadherin, Slug, Snail, Twist and Zeb1. This process is also controlled post-transcriptionally by a complex and regulated network of miRNAs. We have shown that miR-150-5p and miR-661, up-regulated in triple negative breast cancer (TNBC) when compared to normal tissue and other breast cancer subtypes, exert an oncogenic action and modulate cell proliferation, clonogenicity, migration and cytotoxic response in in vitro TNBC models. The main objective of this study was to determine whether the modulation of these phenotypes were due to the regulation of their corresponding gene targets associated with EMT. By conducting an integrated computational and experimental analysis, in which miR-150-5p and miR-661 were suppressed or ectopically expressed in transfected MDA-MB-231 cells, we showed that they present common regulatory roles in cell adhesion and motility signaling networks, including those involved in EMT. Gene expression analysis in a targeted panel of 770 genes with primary functional annotations in EMT, cell adhesion and motility and metastasis, revealed that: i. the suppression of miR-150-5p and miR-661, affected the expression of 160 and 123 genes, respectively; 18% of these genes were commonly affected by both miRNAs, including ACVR1C (ALK-7), CHAD, GIMAP6, SFRCL1, SPARCL1 and TBX1; ii. the ectopic expression of miR-150-5p and miR-661, affected the expression of 283 and 267 genes, respectively; 27% of which commonly affected by both miRNAs, including AKT1, DCL1, MAPK2, MMP1, SFRP1 and TPM2. iii. 26 genes were inversely affected by the suppression and ectopic expression of miR-150-5p and miR-661 (consistent with the general post-transcriptional regulation of miRNA/mRNA targets); 73% of these genes were predicted to be miRs150-5p and 661 direct or indirect targets. In summary, based on the computational and experimental data presented, we provide evidences that strongly suggest that miRNA-150-5p and miR-661 modulate the aggressive tumor phenotype in TNBC cells by regulating common gene targets associated with the EMT process. Further functional studies in TNBC experimental models will allow us to dissect the mechanisms by which they contribute to the TNBC aggressive phenotypes by synergistically regulating EMT.

Funding: Partially funded by Georgetown University Center of Excellence in Regulatory Science and Innovation (CERSI U01FD004319), CNPq, Capes-Brazil (scholarship to PMMO, BMS, ASF).

Citation Format: Patricia MM Ozawa, Bruna M. Sugita, Aline S. Fonseca, Yara Rodriguez, Yuriy Gusev, Paolo Fadda, Deepak Kumar, Luciane R. Cavalli. The synergistic role of miR-150-5p and miR-661 in regulating epithelial mesenchymal transition in triple negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 496.