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Updated: Dec 24, 2025
Assessing Cell Viability and Death in 3D Spheroid Cultures of Cancer Cells
Published on: June 16, 2019
Spermine synthesis inhibitor blocks 25-hydroxycholesterol-induced- apoptosis via SREBP2 upregulation in DLD-1 cell
Miku Kakimoto1, Hideya Yamamoto1, Arowu R Tanaka1
1Laboratory of Physiology and Morphology, Department of Life Sciences, School of Pharmacy, Yasuda Women's University, 6-13-1 Yasuhigashi, Asaminami Ward, Hiroshima City, Hiroshima, 731-0153, Japan.
Abstract:
The oxysterol 25-hydroxycholesterol (25-HC) has diverse physiological activities, including the ability to inhibit anchorage-independent growth of colorectal cancer cells. Here, we found that a polyamine synthesis inhibitor, DFMO, prevented 25-HC-induced apoptosis in non-anchored colorectal cancer DLD-1 cells. Additionally, we found that the spermine synthesis inhibitor APCHA also inhibited 25-HC-induced apoptosis in DLD-1 spheroids. Inhibiting the maturation of SREBP2, a critical regulator of cholesterol synthesis, reversed the effects of APCHA. SREBP2 knockdown also abolished the ability of APCHA to counteract 25-HC activity. Furthermore, APCHA induced SREBP2 maturation and upregulated its transcriptional activity, indicating that altered polyamine metabolism can increase SREBP2 activity and block 25-HC-induced apoptosis in spheroids. These results suggest that crosstalk between polyamine metabolism and cholesterol synthetic pathways via SREBP2 governs the proliferative and malignant properties of colorectal cancer cells.
Insights
Polyamines and cholesterol synthesis pathways interact to control colorectal cancer cell growth. Inhibiting polyamine synthesis blocks 25-hydroxycholesterol-induced cell death in colorectal cancer models.
Area of Science:
- Biochemistry
- Molecular Biology
- Oncology
Background:
- 25-hydroxycholesterol (25-HC) inhibits colorectal cancer cell growth.
- Polyamines are crucial for cell proliferation and survival.
Purpose of the Study:
- To investigate the role of polyamine metabolism in 25-HC-induced apoptosis in colorectal cancer cells.
- To elucidate the involvement of SREBP2 in the interplay between polyamine metabolism and cholesterol synthesis.
Main Methods:
- Utilized colorectal cancer cell lines (DLD-1) and spheroids.
- Administered polyamine synthesis inhibitors (DFMO, APCHA) and 25-HC.
- Assessed apoptosis, SREBP2 maturation, and transcriptional activity.
- Performed SREBP2 knockdown experiments.
Main Results:
- DFMO and APCHA prevented 25-HC-induced apoptosis in non-anchored and spheroid colorectal cancer cells.
- APCHA treatment led to SREBP2 maturation and increased its transcriptional activity.
- Inhibition of SREBP2 maturation or knockdown abolished APCHA's protective effect against 25-HC-induced apoptosis.
- Altered polyamine metabolism enhances SREBP2 activity, blocking 25-HC-induced apoptosis.
Conclusions:
- Crosstalk between polyamine metabolism and cholesterol synthesis via SREBP2 regulates colorectal cancer cell proliferation and malignancy.
- Targeting polyamine metabolism may offer a novel therapeutic strategy for colorectal cancer by modulating cholesterol pathways.
