Acetaminophen & Metformin Attack Breast Cancer Stem Cells
Posted Mar 23 2011 10:51am
An ever-growing body of scientific research continues to suggest that breast cancer stem cells drive tumor formation, metastasis, and breast cancer recurrence. Breast cancer stem cells are cells that are undifferentiated and capable of self-renewal. These cells have been shown to be resistant to breast cancer treatments; therefore, the discovery of new or existing drugs that can specifically target and block breast cancer stem cell activity is imperative. Two newly published studies suggest that two commonly used drugs, acetaminophen and metformin , might effectively block stem cell function.
In the first of these two studies, breast cancer researchers used MDA-MB-231 breast cancer cells that contain stem cells to test the ability of a variety of medicines to cause stem cells to differentiate. The study investigators reported that acetaminophen, a common pain-relief medication, reduced stem cell function . Specifically, the breast cancer researchers noted that in cell culture tests acetaminophen
Induced differentiatian of breast cancer stem cells,
Decreased the ability of breast cancer stem cells to invade, and
Made these cells more susceptible to breast cancer drugs.
Furthermore, the results of this study showed that treatment of the MDA-MB-231 breast cancer cells with acetaminophen before implanting them into mice reduced the ability of these cells to develop into breast tumors. Lastly, the study investigators reported that acetaminophen treatment of mice already implanted with breast cancer cells suppressed the ability of the tumors to grow.
In the second breast cancer study, investigators studied the benefits of metformin alone or in combination with various breast cancer treatment drugs on breast cancer stem cell function and tumor growth. Metformin is primarily used for the treatment of Type 2 diabetes, but research has shown that it can suppress breast cancer stem cell activity. The results of this new metformin breast cancer study showed that
Oral administration of metformin alone and the chemotherapy drug doxorubicin alone to mice with breast tumors reduced tumor growth.
The combination breast cancer treatment of metformin plus doxorubicin both suppressed tumor growth and prolonged remission, indicating that the combination therapy was more effective than either therapy given alone.
Metformin selectively killed breast cancer stem cells in human breast cancer tissue samples.
Combining metformin with doxorubicin, paclitaxel, or carboplatin suppressed breast tumor growth and prolonged relapse.
Lower doses of doxorubicin could be used effectively when used as a combination therapy with metformin.
This second study suggests that metformin alone or in combination can suppress breast cancer tumor growth. These combination treatments appear to be effective due to the different approaches of the two breast cancer treatments. The standard chemotherapy drugs typically attack the non-stem cancer cells, while the metformin attacks the stem cells.
Overall, these two studies confirm the importance of targeting stem cells in the fight against breast cancer. Furthermore, these studies indicate that two commonly used medicines might be effective in targeting cancer stem cells and when given in combination with standard chemotherapy drugs can result in the use of lower doses of the chemotherapy drugs. This provides the possibility of fewer side effects and better quality of life, while still effectively attacking the breast cancer. These are exciting results that will hopefully develop into future improvements is breast cancer treatments.