Abstract
β-caryophyllene (BCP) exhibits anti-proliferative properties in cancer cells. Here, we examine the hypothesis that BCP induces membrane remodeling. Our data show that high concentrations of BCP increase membrane permeability of human breast cells (hBrC) causing detachment and cell death. At a sub-lethal concentration of BCP, we show that BCP induces a striking upregulation of genes involved in cholesterol biosynthesis, including the gene that encodes for HMGCoA reductase (HMGCR), the rate-determining step in cholesterol biosynthesis. In addition, stearoyl-CoA desaturase (SCD) is also upregulated which would lead to the enhanced formation of monounsaturated fatty acids, specifically oleate and palmitoleate from stearoyl CoA and palmitoyl CoA, respectively. These fatty acids are major components of membrane phospholipids and cholesterol esters. Together, these data suggest that cells respond to BCP by increasing the synthesis of components found in membranes. These responses could be viewed as a repair mechanism and/or as a mechanism to mount resistance to the cytotoxic effect of BCP. Blocking HMGCR activity enhances the cytotoxicity of BCP, suggesting that BCP may provide an additional therapeutic tool in controlling breast cancer cell growth.
Abbreviations
- BCP
- β-caryophyllene
- SREBP
- sterol response element binding protein
- SCAP
- SREBP cleavage activating protein
- TNBC
- triple negative beast cancer
- SCD
- stearoyl-CoA desaturase
- HBrC
- human breast cancer cells
- LDH
- lactate dehydrogenase
- ER
- endoplasmic reticulum
- HMGCR
- HMG CoA reductase
- INSIG
- insulin induced gene
- S1P and S2P
- site 1 protease and site 2 protease
- STARD4
- StAR related lipid transfer domain containing 4
- GRP78
- glucose-regulated protein 78
- PFO
- perfringolysin O
- HER2
- human epidermal growth factor 2