Impact of HDL on breast cancer risk

The heart disease is known to be protected by the presence of large quantities of high density lipoprotein (HDL) or good cholesterol. Recently, some animal studies have revealed that higher HDL levels are found to be increasing the risk of breast cancer. HDL is also known to be enhancing the cancer aggressive nature in the experiments conducted in animals.

The researchers have shown that the increased risk of breast cancer might be due to the presence of HDL receptor on the breast cancer cells. The HDL receptor might be a new molecular target which might aid in treating the disease. The researchers at Thomas Jefferson University found that HDL receptors on breast cancer cells are responsible for the negative impact of HDL on breast cancer risk. The researchers also showed that blocking the activity of the HDL receptor on the breast cancer cells will help in reducing the risk for the disease, though HDL is simultaneously satisfying the usual levels present in the blood vessels.

The researchers at Thomas Jefferson University have studied the effect of HDL on the breast cancer cells. They studied on the impact of HDL on the breast cancer cell lines and identified that HDL activated the signal pathways that are active during the progression of cancer. They also observed the state of metastasis changed from the normal state of the cells.

The expression of the HDL receptor called as SR-BI was decreased by the researchers by using silencing RNA. The signal pathways that enhanced the progression of tumor were decreased. It is also shown that cells with lower number of SR-BI receptors exhibited decreased rate of proliferation and ability of migration compared to the cells that had normal number of SR-BI receptors.

In some of the tumorigenesis studies done in mouse models, the tumor formation is decreased with decreased SR-BI levels. The research people used a drug known as BLT-1 to block the SR-BI receptor present in the breast cancer cells. This blockage was done to observe the decreased signaling and proliferation of the cells through the proteins meant for tumor development. Therefore, the study done by the researchers at Thomas Jefferson University has revealed that HDL has a strong impact on the aggressive development of breast cancer. Inhibiting the utility of SR-BI receptors in the breast cancer cells might reduce the growth of cancer.

Some more studies have to be done further to identify the exact drugs that are responsible for blocking the SR-BI receptors. The study also has to be conducted to identify the amount of cholesterol necessary for the tumor to develop prior to the reduction and modification of lipid content in the cancer patients.