Abstract 5581: Melatonin and 17β-estradiol treatment modulating TIMP’s family gene expression profile in IDCC

Introduction: Tissue Inhibitor of Metalloproteinases (TIMPs) are genes that encodes four (TIMP1-4) proteins that act as endogenous protease inhibitors. They regulate directly the matrix metalloproteinases (MMPs) known to be associated with growth and invasiveness of sundry cancer types, including breast cancer cells. Several evidences have shown that melatonin can present both anti-proliferative and invasiveness role in cancer, while estrogen seems to have the opposite function. Thus, our goal was to evaluate the expression of TIMPs’ family compounds in invasive ductal carcinoma cells (IDCC) of breast cancer after treatment with 17β-estradiol (malignancy inducer), melatonin (malignancy inhibitor), isolated and associated with each other. Methods: IDCC [T47D (ER+/PR+), MCF7 (ER+), and MDA-MB231 (triple-negative)] were cultured as recommended by ATCC. All three cell lines were plated (5X105 in 6 wells plate) and treated with 17β-estradiol (E2 - 100 nM), Metatonin (Mel - 3000 μM) or both (Mel + E2). After treatment the RNA was extracted using mirVana miRNA Isolation Kit (Ambion, CA, USA) and then, purity and concentration of total RNA were accessed. The Reverse transcription synthesis was performed using High-Capacity cDNA Reverse Transcription Kit and RT-PCR was accessed for TIMP 1 - 4 using TaqMan assay system. The beta2-microglobulin (B2M) was established as a housekeeping gene and the relative quantification was determined by 2-DDCT method. Results: All members of the TIMPs’ family were expressed in IDCC tested with significant differences in their expression when compared to control cells. Mel treatment led to TIMP1, -3 and -4 mRNA upregulation, while E2 upregulated TIMP1 but downregulated TIMP2 in T47D cells. Otherwise, TIMP1 and -3 were downregulated and -2 and -4 were upregulated in MCF7 cells treated with Mel, while an increase of TIMP1, -2 and -4 were observed for E2. In comparison with control group, E2 treatment of MDA-MB231 cells led to upregulation of TIMPs -1, -3 and -4, and Mel upregulated all, except TIMP4 that was downregulated. Conclusion: Melatonin and 17β-estradiol treatments seems to modulate negative or positively the gene expression profile of all the assessed members of TIMPs’ family in IDCC cells. Citation Format: Kelly P. Ferreira, Bruna C. Almeida, Katia C. Carvalho. Melatonin and 17β-estradiol treatment modulating TIMP’s family gene expression profile in IDCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5581.