Abstract 1477: Melatonin regulates the tumor suppressor miR-148a-3p involved in angiogenesis and metastasis of breast cancer

Abstract

Abstract Women with breast cancer has the tumor progression and angiogenesis-induced metastasis as the main cause of death. MicroRNAs (miRNAs) are small noncoding mRNA molecules that play an important role in gene regulation and once deregulated, these molecules may be involved with the progression of different human tumor types, including breast cancer. These miRNAs play an oncostatic role on tumor suppressor genes and regulate the process of angiogenesis, tumor growth and metastasis. So as new possible adjuvant treatment against breast cancer our group have shown melatonin, that is a hormone secreted by the pineal gland, by exhibiting several anti-tumor and antiangiogenic effects. Therefore, the aim of this study was to evaluate the potential therapeutic of melatonin on miRNAs regulation to verify breast cancer progression and potent tumor suppressor miR-148a-3p. In silico analysis was performed for selection of miRNAs involved in breast cancer. The MDA-MB-231 breast cancer cell line (metastatic negative estrogen receptor) was grown and separated in two different experimental conditions maintained for 24 hours: control group and melatonin-treated group (concentration of 1 mM). After this period the extraction of total RNA was performed (Qiagen®) and the total concentration of miRNAs of each sample was determined (NanoDrop Spectrophotometer 2000C - Thermo Scientific®). Differential expressions of these miRNAs was evaluate using miScript miRNA PCR-Array (Qiagen®) containing 84 miRNAs associated with breast cancer. The overexpression of miR-148a-3p in MDA-MB-231 cells was performed by bacterial cloning vector and the relative quantification of gene expression of their target IGF-1R and VEGF by real-time PCR. Moreover, the quantification of protein expression was performed by immunocytochemistry of IGF-1R and VEGF. Lastly, the migration and invasion cell assays were carried out to assess the potential capacity of these cells to undergo metastasis. The analysis of miRNAs MDA-MB-231 cell line by PCR-array showed 24 upregulated miRNAs and 8 miRNAs downregulated after the treatment with melatonin. Relative quantification shows that the melatonin treatment increases the gene expression of miR-148a-3p and decreases the gene and protein levels of IGF-1R and VEGF. The capability of migration and invasion of the breast cancer cells decreased after treatment with melatonin and overexpression of miR-148a-3p. Our results confirm the action of melatonin on the miR-148a-3p regulation known being involved in the progression of breast cancer. Thus the establishment of this therapeutic protocols can control these cellular events essential for the prognosis of patients with breast cancer. Citation Format: Debora Zuccari, Jéssica Zani Lacerda, Lívia Carvalho Ferreira, Beatriz Camargo Lopes, Andrés Felipe Aristizábal-Pachón, Marcio Chaim Bajgelman. Melatonin regulates the tumor suppressor miR-148a-3p involved in angiogenesis and metastasis of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1477. doi:10.1158/1538-7445.AM2017-1477