Tiger nut extracts inhibit cell migration, RhoA, and RhoC GTPases, but induce Rac1/2/3 in MCF7 and MDA‐MB231 cancer‐origin cell lines

Abstract

Background/AimsBreast cancer is the most common female cancer worldwide. The high mortality of breast cancer patients is increasing over the years due to the late stage discovery of the cancer when the cancer cells may have already metastasized. In many developing and underdeveloped countries such as Ghana, the delay in cancer detection is partly due to the cost of the various treatments available which forced the women to first fall on orthodox medicine or herbal products. A proper investigation and mechanism of action of known medicinal plants to help alleviate this burden is therefore needed. Tiger nut is an underutilized crop in Ghana, with high nutritional values, but consumed raw as snack or blended for its milk. A study on its antioxidant and cytotoxicity effects showed that it has an anti‐proliferative effect on MCF7 and MDA‐MB‐231 breast cancer‐origin cell lines. This work investigated the effects of Tiger nut extracts on the migration and invasion of the mentioned cell lines, and on the Rho GTPase pathways.MethodologyCell lines were cultured in DMEM (Low glucose) supplemented with 10 % FBS, and 1 % penicillin. The migration effect was studied by the scratching assay where plated cells were wounded, treated, incubated and pictures taken at 0 h, 12 h, and 24 hours time points. The invasion assay was performed using Matrigel invasion kits on MDA‐MB‐231. Finally, cytoplasmic proteins were extracted by lysing the cells with Thermo‐Fisher mper lysis buffer and Western blotted for Rho A, Rho C, and rac1/2/3.ResultsAqueous and Ethanol extracts have been found to inhibit the migration of the investigated cell lines. However, only ethanolic extract was found to reduce the invasiveness of MDA‐MB‐231 at almost 50 %. Rho A, and Rho C were down‐regulated by all extracts whereas Rac1/2/3 was up‐regulated in MCF7.ConclusionRho A and Rho C are known to positively contribute to tumour progression. Their down‐regulation might therefore be responsible for the inhibition in cell migration observed. Even though the over expression of Rac may assemble lamellipodia at the leading edge of the cell, the down regulation of the Rho A, and C could not generate the contractile force needed to migrate. Thus, the cell will be static or round up in case of absence of Rho B, which may be the reason of the anti‐proliferative behaviour observed from previous studies.Support or Funding InformationThe work was supported by Universiti Sains Malaysia. Seyram Elom Achoribo is recipient of The World Academic of Sciences‐Universiti Sains Malaysia (TWAS‐USM) fellowship.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.