Antiproliferative Effect of 7-Ketositosterol in Breast and Liver Cancer Cells: Possible Impact on Ceramide, Extracellular Signal-Regulated Kinases, and Nuclear Factor Kappa B Signaling Pathways

Abstract

-Ketositosterol (7-KSS) was the focus of this investigation because of its potential
effects on sphingomyelin/ceramide metabolites and cell death in HepG2 and MCF-7 human
liver cancer cells. Methods: At various concentrations and times, the anti-proliferative effects
of 7-KSS therapy were evaluated. Cell viability was determined by MTT analysis, while
sphingomyelins (SMs), ceramides (CERs), and sphingosine-1-phosphate (S1P) levels were
analyzed by LC-MS/MS. Western blot analysis and immunofluorescence labeling were used
to determine the amounts of phosphorylated 44/42 ERK1/2 and NF-κB p65 (Ser536) proteins.
The process of cell death was examined by using flow cytometric analysis of annexin-V and
propidium iodide (PI) labeling, as well as TUNEL staining. In comparison to control cells, 7-
KSS treatment considerably reduced cell viability and levels of S1P, p-44/42 ERK1/2, and pNF-κB p65 proteins in cancer cells. In cancer cells treated with 7-KSS, apoptosis and
intracellular levels of C16-C24 CERs were shown to increase significantly. Results: S1P, p44/42 ERK1/2, and p-NF-κB p65 protein levels were downregulated by 7-KSS, which
decreased cell proliferation and increased ceramide buildup and apoptosis.