Dados do Resumo

Título

miR-376a-3p expression in breast cancer cells treated with melatonin and 17β-estradiol

Introdução

miRNAs are small non-coding RNAs that regulate negatively gene expression. Alterations in miRNAs expression may be responsible for the neoplasm's advent including breast cancer development. It is known that melatonin (MT) and 17β-estradiol (E2) play key roles in tumor suppression and mammary oncogenesis, respectively, opening the scope for searching their actions on miRNAs involved in these processes.

Objetivo

We aimed to evaluate the expression profile of miR-376a-3p in ER+ and triple-negative breast cancer cells treated with MT and E2.

Métodos

T47D (ER+) and MDA-MB231 (triple-negative) cells were cultured in specific mediums and conditions (ATCC recommendations). Cell lines were plated at a concentration of 5X105 in 6 wells plate and treated with 3000 µM of MT isolated and 100 nM of E2 isolated, and MT and E2 associated. The drugs were daily replacements. T47D was cultured for 48h under treatment and MDA-MB231 was evaluated 72h after treatment. A total RNA was extracted from cell lines and the purity and concentration of miRNA were verified. The cDNA synthesis for each sample was performed, and RT-PCR was carried out for miR-376a-3p using TaqMan assay. The miR-320a was used as the housekeeping gene. Relative quantification was set up comparing cycle threshold by 2-DDCT method.

Resultados

T47D cells showed low expression of miRNA-376a after the treatments with MT isolated (p<0.0001), E2 isolated (p<0.0001) and MT associated with E2 (p<0.0001), compared to cellular control (CC). Between them, we observed that MT treatment presented higher expression of miR-376a compared to MT + E2 (p<0.05). As well as the T47D, the MDA-MB231 cells presented a significant low expression of miRNA-376a after the treatments with MT isolated (p<0.0001), E2 isolated (p<0.0001) and MT associated with E2 (p<0.0001), compared to CC. In addition, this cells showed a lower expression of miR-376a in MT + E2 treatment related to MT (p<0.0001); E2 had a significant higher expression compared to MT + E2 (p<0.0001).

Conclusões

MT and E2 treatments seems to reduce the expression of miR-376a-3p. However, with associated treatment it is possible to obtain a marked diminished expression, showing that all treatments had an action on miR-376a-3p. Still, the one that stands out the most is the treatment carried out with MT and E2 associated, both in the T47D and MDA-MB231 cell lines.

Financiador do resumo

Funded by Fundação de Amparo à Pesquisa do Estado de São Paulo - FAPESP 2022/04174-2 and 2018/24224-9

Palavras Chave

melatonin; Estrogen; miRNA