Cholesterol‐Lowering Treatment Blocks Epithelial‐Mesenchymal Transition (
EMT
) Associated Invasiveness and Drug Resistance in Breast and Colorectal Adenocarcinoma Models
Shanen Perumal, Naaziyah Abdulla, Ruth Aronson, Mandeep Kaur ABSTRACT
Background
Epithelial‐mesenchymal transition (EMT) is a cellular process involved in the invasion and metastasis of cancer cells. Deregulated cellular cholesterol is associated with treatment resistance and metastatic potential in cancer cells; however, the link between EMT and cholesterol is unclear.
Methods
We tested the effect of cholesterol‐lowering on EMT using three cell line models and three EMT inducers. EMT was induced in NMuMG, MCF‐7 and HT‐29 cells to assess the effect of cholesterol‐modulatory compounds, MβCD, HPβCD and simvastatin. Free cholesterol, lipid droplets and lipid rafts in cellular membranes were evaluated using immunofluorescence microscopy. Expression of EMT‐associated genes was assessed using immunofluorescent staining, RT‐qPCR and Western blotting.
Results
Following cholesterol depletion (free cholesterol, lipid rafts and lipid droplets) with HPβCD, RT‐qPCR showed an increase in CDH1 expression (log 2 fold change [log 2 FC] = 2.03; p < 0.001), and a decrease in Vim (log 2 FC = −1.01; p < 0.05) in NMuMG cells post EMT. Expression of cholesterol biosynthesis gene HMGCR (log 2 FC = −1.72; p < 0.01), and efflux genes ABCA1 (log 2 FC = −1.74; p < 0.01) and ABCG1 (log 2 FC = −4.81; p < 0.001) were reduced. A 68.4% ( p < 0.001) reduction in relative invasion in NMuMG cells and a 41.3% ( p < 0.01) reduction in multidrug resistance measurements in MCF‐7 cells were observed post‐EMT after HPβCD treatment.
Conclusion
Cholesterol depletion reversed EMT‐associated expression patterns in all three cell models. Results from this study support cholesterol depletion as a potential therapeutic intervention for mitigating metastatic cancer progression.