ANTITUMOR EFFECTS OF THE SSI6 SUBSTANCE DERIVED FROM GINGER ON BREAST CANCER CELLS

Liany J. Luna1, Marina A. Naves1, James A. da Silva2, Márcia R. Cominetti1

Institution: Universidade Federal de Sao Carlos

Objective: this study intends to evaluate the substance SSi6 as its capacity to alter the behavior of MDA-MB-231 triple negative breast tumor (TNBC) cell line, considering changes in cell morphology, proliferation rate and cytotoxic effects. Methodology: to verify the effects of SSi6 over the morphology, MDA-MB-231 TNBC cells were plated in 12-well plates and after 24h of incubation, different concentrations of the substance (6.25-100µM) were added to the wells. Images were taken using (inverted microscope and camera).In the proliferation assay, cells were plated in 96-well plates and exposed to increasing concentrations of the substance; next, cells were treated with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] in order to form formazan crystals, which were subsequently diluted with DMSO (dimethyl sulfoxide).Plates were analyzed in spectrophotometer with 540 nm wavelenght. The IC50 (concentration that inhibits 50% of cell proliferation) value for SSi6 was calculated through GraphPad Prism 6.01 software. In the clonogenic assay, cells were plated in Petri dishes, then, incubated with increasing concentrations of SSi6. Next, treatment was removed and replaced by new culture medium with no treatment. Plates were maintained in an incubator for 10 days and after this period; cells were fixed, stained and analyzed through ImageJ software. Results: SSi6 affected the morphology of TNBC, causing vacuoles formation and inhibiting cell adhesion after 2h of treatment at 50µM.This result is much more evident after 24h of treatment. The proliferation assay indicated that SSi6 was able to inhibit MDA-MB-231growth and proliferation (IC50=22.90µM) and moreover, had a cytotoxic and cytostatic effect after 48h at 15µM as it can be seen in the clonogenic assay. Conclusion: results suggest that SSi6 substance affects in a significant manner the morphology and proliferation of TNBC and makes this substance a new potential candidate to be further investigated as an antitumor drug that could be used to improve current chemotherapy.

Keywords: breast cancer, antitumor activity, natural products, ginger.”