Soy isoflavones boost effect of radiation for killing lung cancer cells

Kathleen Blanchard's picture
Lung cancer

Compounds in soy improves radiotherapy for lung cancer

Researchers are working on a non-toxic way to help kill cancer cells using compounds in soy. Radiation therapy given to treat lung cancer can destroy normal tissue. Investigators at Wayne State University's School of Medicine and the Karmanos Cancer Institute in Detroit say soybean isoflavones can sensitize cancer cells to the effect of radiation and protect normal tissue.

Soy inhibits cancer survival mechanism

The scientists explain soy inhibits mechanisms used by cancer cells to survive. Dr. Gilda Hillman, an associate professor in the Department of Radiation Oncology says, "At the same time, soy isoflavones can also act as antioxidants in normal tissues, which protect them against unintended damage from the radiotherapy."

Recent research, published in the Journal of Thoracic Oncology, showed the soybean compounds block DNA repair in cancer cells, making them more vulnerable to destruction with radiation therapy.


Pre-treating cancer cells with soy isoflavone pills is a non toxic way to increase radiation's effect while protecting normal tissue.

Soy has antioxidants says Hillman that can protect normal tissue from being harmed from lung cancer radiotherapy. In the study, the researchers treated cancer cells with a formulation of genistein, daidzein and glycitein, three main isoflavones found in soybeans.

They found human A549 non-small cell lung cancer (NSCLC) cells had more DNA damage. Soy impaired the ability of cancer cells to repair, making radiation therapy more effective.

The study shows soy compounds have anti-tumor effects that can be used as a non-toxic way to boost the effect of radiation for lung cancer treatment. Pure genistein in soy pills have been used in clinical studies and shown to help destroy cancer cells. The researchers found the combination of genistein, daidzein and glycitein in soybeans is even more potent.

Journal of Thoracic Oncology. 6(4):688-698, April 2011.
doi: 10.1097/JTO.0b013e31821034ae
"Soy Isoflavones Augment Radiation Effect by Inhibiting APE1/Ref-1 DNA Repair Activity in Non-small Cell Lung Cancer"
Singh-Gupta, Vinita; Joiner, Michael C.; Runyan, Lindsay; Yunker, Christopher K.; Sarkar, Fazlul H.; Miller, Steven; Gadgeel, Shirish M.; Konski, Andre A.; Hillman, Gilda G.