Exploring the Therapeutic Potential of Fluorinated CXCR4 Inhibitor A1: Insights from Breast Cancer In Vitro Investigations

The impacts of the CXC motif chemokine 12 (CXCL12)/ C-X-C chemokine receptor type 4 (CXCR4) axis on the infiltration of anti-tumor and pro-tumor immune cells in the tumor microenvironment (TME) of breast cancer (BCa) have been noted in previous studies. Accordingly, regulating the downstream signals of this axis can effectively increase CD8+ cytotoxic T cells and decrease the frequency of immunosuppressive cells in the TME. This study investigated the anti-tumor effects of N, N''-thiocarbonylbis (N'-(3,4-dimethylphenyl)-2,2,2 trifluoroacetimidamide) (A1), a novel fluorinated CXCR4 inhibitor on a BCa cell line. In this study, the impacts of A1 on cell viability, proliferation, apoptosis, and cell cycle were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays. Moreover, the effect of A1 on the number of CXCR4+ 4T1 cells was measured by flow cytometry. A1 treatment exhibited cytotoxic effects on 4T1 cells, promoting cell apoptosis and G2/M cell cycle arrest. In addition, A1-treated cells showed a reduced cell proliferation than CXCL12 treated cells. Furthermore, treatment with A1 alongside CXCL12 significantly decreased the number of CXCR4+ cells compared to the control group treated with only CXCL12 as a proliferator factor. These results indicate that A1 exerts potential anti-tumor effects and may serve as a possible therapeutic agent for BCa treatment; however, further studies are required.