Synergistic Cytotoxicity of Cafestol and Kahweol With Doxorubicin in Breast Cancer Cells Involves TNF‑α Targeting and NF‑κB Downregulation.

Breast cancer (BC) is the most common cancer in women worldwide. Natural compounds have been studied to improve chemotherapy efficiency. Cafestol and kahweol (C&K) are diterpenes from coffee lipid fraction, with potential anticancer activity, whose effects and association with chemotherapeutic drug doxorubicin in BC cells are still unknown. Here, we evaluated the synergistic cytotoxic effects of the C&K with doxorubicin and their molecular mechanisms in BC cells. Cell viability was assessed by the MTT assay. Flow cytometry was used to analyze apoptosis, cell cycle, and NF-κB levels. The microarray assay was performed to identify altered signaling pathways, and molecular docking was utilized to predict the interaction between C&K and TNF-α. In addition, TCGA data were explored to evaluate the clinical association between the expression of C&K-regulated genes and TNF-α/NF-κB pathway genes. C&K was cytotoxic and increased the doxorubicin cytotoxicity, augmented the sub-G0/G1 phase, downregulated TNF-α/NF-κB pathway, decreased NF-κB protein levels, and showed affinity for TNF-α by molecular docking. Moreover, considering the C&K-modulated genes, BLOC1S1 acted as a protective factor for BC, and these genes were negatively correlated with TNF-α/NF-κB genes. Our data suggest that C&K have cytotoxic properties by inhibiting TNF-α/NF-κB pathway and interacting synergistically with doxorubicin in BC cells.