(P26-063-25) 24-Methyl Cholesterol Modulates NAMPT Activity and Glucose Metabolism in Renal Cell Carcinoma

Objectives: 1) Investigate the effect of 24-methyl cholesterol on glucose uptake in 3T3-L1 adipocytes and renal cell carcinoma (RCC) cells; 2) Examine the effects of 24-methyl cholesterol on NAMPT activity and AMPK phosphorylation in RCC cells; 3) Correlate the inhibition of glucose uptake and AMPK phosphorylation with changes in NAMPT activity

Methods: 3T3-L1 differentiated adipocytes and Caki-1 RCC cells were exposed to varying concentrations of 24-methyl cholesterol (0.1 µM, 1 µM, 10 µM, 100 µM, 1 mM, 10 mM) to evaluate its effect on glucose uptake. The effects of 24-methyl cholesterol on AMPK phosphorylation and NAMPT activity were evaluated using a combination of ELISA and enzymatic activity assays.

Results: 24-methyl cholesterol inhibited glucose uptake in both 3T3-L1 adipocytes and RCC cells. In addition, it reduced AMPK activity in 3T3-L1 adipocytes and RCC cells and blunted the activity of purified recombinant NAMPT. These findings suggest that 24-methyl cholesterol may inhibit AMPK through a mechanism involving altered NAD+ metabolism, particularly via a NAMPT-dependent mechanism.

Conclusions: Our results show that 24-methyl cholesterol modulates cellular glucose metabolism in RCC cells, likely by disrupting NAMPT activity and AMPK signaling. These effects may underlie its potential anti-cancer properties, offering novel insights into therapeutic strategies targeting energy metabolism in RCC. Further studies are warranted to validate these findings in vivo and explore the clinical potential of 24-methyl cholesterol and cancer therapy.

Funding Sources: This work was funded by the Virginia Academy of Science and the Liberty University Office of Sponsored Programs and Research, School of Health Sciences, and Department of Biology and Chemistry.