Single molecule recognition of CD95 receptors on the surface of HepG2 cells under the curcumin

Hepatocellular carcinoma (HCC) is a serious concern worldwide. The published reports showed that aberrant CD95 receptor expression plays a critical role in apoptosis in liver cancer. While curcumin has shown promise in inducing apoptosis in liver cancer cells, its direct effects on CD95 expression during this process have not been thoroughly investigated. This study aims to quantitatively assess the expression of the CD95 receptor in HepG2 cells treated with different concentrations of curcumin using techniques such as fluorescence staining, single-molecule force spectroscopy (SMFS), and single-molecule recognition imaging (SMRI). Fluorescence staining results indicate a significant increase in CD95 expression following curcumin treatment. For the first time, SMFS and SMRI techniques were used to directly reveal the binding sites of CD95 on the cell membrane, with the number of binding sites increasing as the curcumin concentration increased. Additionally, the binding force between an antibody-modified probe and CD95 was strengthened with curcumin treatment, suggesting that curcumin enhances both the quantity and affinity of CD95 binding sites. This study provides new insights into curcumin-induced CD95-mediated apoptosis in liver cancer cells and highlights the potential of AFM techniques for investigating drug mechanisms. Overall, these findings may inform innovative therapeutic strategies for liver cancer and improve drug design processes.