7Beta-Hydroxycholesterol

Biol. Pharm. Bull., 2005, 28(8):1377-80.

Cytotoxic effect of 7beta-hydroxycholesterol on human NCI-H460 lung cancer cells.[Pubmed: 16079477]

The cytotoxic activity of 7Beta-Hydroxycholesterol (7beta-OHC) was evaluated on human NCI-H460 lung cancer cells.
METHODS AND RESULTS:
7beta-OHC decreased clonogenic survival of NCI-H460 in a dose dependent pattern. 7beta-OHC induced apoptosis in NCI-H460, with the characteristic features like increase in sub-G(1) hypodiploid (apoptotic) cells, and apoptotic body formation, as evidenced by flow cytometry and fluorescence microscope, respectively. Apoptosis was also associated with loss of mitochondrial transmembrane potential, and the activation of caspases 9 and 3. 7beta-OHC resulted in generation of reactive oxygen species (ROS) during apoptosis.
CONCLUSIONS:
On the whole, the results indicated that 7beta-OHC inhibited the proliferation of NCI-H460 cells through apoptosis via caspase activation.

Anticancer Res., 2002, 22(2A):943-8.

Effects of combinations of 7beta-hydroxycholesterol and anticancer drugs or ionizing radiation on the proliferation of cultured tumor cells.[Pubmed: 12014676]

Oxysterols compose a large class of natural substances endowed in a number of cases with marked antiproliferative and cytotoxic activities.
METHODS AND RESULTS:
The consequences of treatments combining 7Beta-Hydroxycholesterol (7beta-OHC) or XG-142 (a galactose-linked hydrosoluble derivative of 7beta-OHC) with drugs used in cancer chemotherapy or gamma radiation has been evaluated upon a variety of tumor cell lines: Hep-G2, U937, K562 cells, its adriamycin-resistant variant K562 Adr+ and RDM4. Proliferation was assessed by the Uptiblue assay and the [3H]Thymidine incorporation test.
CONCLUSIONS:
Results indicated that 7beta-OHC increased the sensitivity of tumor cells to adriamycin, VP-16, 5-FU and bleomycin to various degrees. 7beta-OHC was found to reinforce the susceptibility of K562 adriamycin-resistant cells to this drug. In RDM4 cells, an enhanced radiosensitivity by 7beta-OHC was also obtained, whereas XG-142 was less efficient in provoking such an effect.