Investigation of potential anti-metastatic effect of metformin and caffeic acid combination therapy in breast cancer cell line in in-vitro culture model.

The invasion and metastasis of cancer cells transform localized cancers into systemic and life-threatening diseases, posing one of the most significant challenges in cancer treatment. This study tested the hypothesis that combined treatment with Caffeic acid (CA) and metformin (MTF) could inhibit or reduce effective signaling pathways involved in the proliferation, survival, and metastasis of MCF-7 breast cancer cells. Anti-proliferation analysis determined the IC50 values for MTF (4.5 mM) and CA (163 µM) after 72 h. Cell migration analysis showed that MTF and CA significantly inhibited MCF-7 cell migration by the 72nd hour, both alone and in combination, without affecting HME1 healthy cell migration from the 48th hour. Colony formation analysis revealed that CA completely inhibited colony formation in MCF-7 cells, while MTF reduced it by 19%. ELISA results indicated that neither CA nor MTF affected the levels of VEGF-A, E-cadherin, or TINAGL-1 proteins, which are involved in MCF-7 cell migration and invasion. However, MTF significantly reduced IL-1β protein levels, and CA significantly reduced IL-4 protein levels in MCF-7 cells. RT-qPCR results largely supported the ELISA findings. Overall, CA and MTF exhibited potential to inhibit MCF-7 cell apoptosis, migration, tumor microenvironment modulation, and metastasis.