Abstract A71: Evaluation of ruthenium complex [Ru(AmSal)(dppe)2]PF6 on the proliferation, morphology, and migration of triple-negative MDA-MB-231 breast tumor cells
Authors: Popolin Cecília Patrícia , Becceneri Amanda Blanque , Graminha Angélica Ellen , Batista Alzir Azevedo , Cominetti Márcia Regina 
Published: August 2018

Abstract
Breast cancer is the most prevalent type of cancer in women and the second leading cause of cancer death worldwide. Triple-negative breast cancer (TNBC) is a highly aggressive breast cancer subtype responsible for 10-20% of breast cancers. The limited efficacy of current systemic and targeted therapies against TNBC metastatic breast tumor metastases leads the search for new types of treatments. The development of antitumor metal-based drugs was started with the discovery of cisplatin; however, its side effects represent a limitation for clinical use. The ruthenium (Ru) molecule has some unique properties that justify its use as candidates for antitumor compounds, such as its ability to mimic iron for binding several biomolecules, including transferrin. The aim of this study was to evaluate the effects of the complex [Ru(AmSal)(dppe)2]PF6 on the proliferation, morphology, and migration of TNBC MDA-MB-231. For the proliferation assay, cells (1x104/100µL) were plated on 96-well plates for 24h. The culture medium was removed from the wells and fresh medium containing [Ru(AmSal)(dppe)2]PF6 (0,36 - 100µM) was added to the wells and incubated properly for 24h. After incubation, the culture medium of each well was removed and a solution containing MTT (1mg/mL) was added (100µL/well). The absorbance was read on an ELISA plate reader (540nm). For cell morphology MDA-MB-231 cells (1x105/mL) were seeded on 12-well plates for 24h. Cells were allowed to grow overnight and then treated or not (control) with the complex (0.15 9.6 µM) for 24h. Cell morphology was examined under an inverted microscope (Nikon, T5100) with amplification of 100×. Cell migration was investigated by two methods, wound healing and transwell assays using Boyden chambers. For wound healing, MDA-MB-231 cells (2x105/mL) were plated in 12-wells plates and incubated properly until the culture reached 100% of confluence. Afterwards, a straight scratch was made and then cells were incubated with complex (0.15 1.20 µM) for 24h. Cells were viewed using an inverted microscope (Nikon, T5100) at 40× total magnification and images were captured (Moticam, 1000-S camera) at 0 h, 24 h. Closure area of migrating cells was measured and the percentage of wound closure was calculated. Cell migration was also assessed using 24-well Boyden chambers. MDA-MB-231 (0.5x105/350µL) cells, incubated or not with complex (0.15 1.20 µM) were seeded on the upper chamber in a DMEM incomplete medium (without FBS). In the lower chamber DMEM medium supplemented with 10% FBS was added. Cells were allowed to migrate for 22h. Then, cells that remained in the upper chamber were removed using a cotton swab. Cells that migrated to the other side of the upper chamber membrane were fixed (methanol) and stained with 1% toluidine blue. Migrated cells were quantified by manual counting and inhibition ratio was expressed as % of control. The results demonstrate that complex [Ru(AmSal)(dppe)2]PF6 has potent cytotoxic activity against breast tumor cells MDA-MB-231 (IC50 1.35 μM). The incubation of the complex with MDA-MB-231 profoundly altered their morphology, promoting the appearance of round cells, also indicating cell death. The complex was also able to inhibit the MDA-MB-231 cell migration in the highest concentrations tested, which were not cytotoxic to the cells. The results show that complex [Ru(AmSal)(dppe)2]PF6 complex was effective in promoting cytotoxic effect on TNBC MDA-MB-231 cells, altering their morphology and inhibiting migration of these cells. This work supports the evidence that complex [Ru(AmSal)(dppe)2]PF6 should be further studied in order to explore its potential of action on TNCB cells and could be used as a model for the design of a new antitumor drug to be applied in chemotherapy.
Citation Format: Cecília Patrícia Popolin, Amanda Blanque Becceneri, Angélica Ellen Graminha, Alzir Azevedo Batista, Márcia Regina Cominetti. Evaluation of ruthenium complex [Ru(AmSal)(dppe)2]PF6 on the proliferation, morphology, and migration of triple-negative MDA-MB-231 breast tumor cells [abstract]. In: Proceedings of the AACR Special Conference: Advances in Breast Cancer Research; 2017 Oct 7-10; Hollywood, CA. Philadelphia (PA): AACR; Mol Cancer Res 2018;16(8_Suppl):Abstract nr A71.