Cholesterol is an important structural component of cell membranes and is found in all animal cells, but cancer cells also need cholesterol to fuel their growth. Now, a new study shows that a compound designed as a cholesterol-lowering drug can kill cancer cells and stop tumor progression in hormone-dependent breast cancers, which represent the majority of breast cancers in women.
Researchers at the University of Missouri (MU) led by Salman Hyder, professor of biomedical sciences in the College of Veterinary Medicine, describe their findings in the journal Breast Cancer Research and Treatment.
Prof. Hyder, who also works at MU's Dalton Cardiovascular Research Center and is Zalk Endowed Professor in Tumor Angiogenesis, says scientists looking for ways to cure breast cancer often seek out targets that slow or stop the disease by killing cancer cells:
"In our study, we targeted the production of cholesterol in cancer cells leading to death of breast cancer cells."
Compound targets cholesterol production in hormone-dependent cancer
Researchers have already established that around 70% of breast cancers in women depend on the hormone estrogen to keep them growing. These can be treated with drugs like tamoxifen that target the hormone as a way to starve the cells.
Researchers say cholesterol contributes to hormone resistance because cells use it to make hormones.
However, while the cancer may at first respond to hormone treatment, eventually most develop resistance to anti-hormone drugs and the cells begin to grow and spread again.
Cholesterol can also contribute to hormone resistance because cells use it to make hormones. This is what interested the team - perhaps they could attack the hormone-dependent cancer via these cholesterol pathways instead of trying to tackle the hormone directly.
So they took human breast cancer cells in the lab and gave them a compound initially developed for the treatment of high cholesterol.
The compound, a cholesterol biosynthesis inhibitor made by Roche Pharmaceuticals, works in a different way to statins.
Compound also destroys estrogen receptors
They found the cholesterol-lowering compound reduced growth of the breast cancer cells, and in many cases also caused their death. Plus, it destroyed an estrogen receptor - a protein that spurs tumor cell growth.
Having shown the compound's effects in cell cultures, the team then tested it in mice with breast cancer. They found the molecule killed the breast cancer cells by destroying their estrogen receptors.
Prof. Hyder summarizes the findings:
"The compound exhibited anti-tumor properties in both human samples, which were outside the body, and in samples that were administered by injection into the mice. In both cases, the proteins that cause tumors to grow were eliminated, leading to more aggressive cell death."
He says it should be possible, with further clinical testing, to develop a drug that fights both high cholesterol and cancer.
A grant from the Department of Defense Breast Cancer Program and the National Institutes of Health helped fund the study.
In April 2014, Medical News Today learned how researchers at the Johns Hopkins Kimmel Cancer Center in Baltimore, MD, developed a blood test that predicts breast cancer recurrence. The test - which appears to deliver a response as early as 2 weeks - looks for signs of hypermethylation, a process that silences genes that keep cancers in check.