Scientists at Mount Sinai School of Medicine have discovered a subpopulation of cells that display cancer stem cell properties and resistance to chemotherapy, and participate in tumor progression. This breakthrough could lead to the development of new tests for early cancer diagnosis, prognostic tests, and innovative therapeutic strategies, as reported in Cancer Cell.
Resistance to chemotherapy is a frequent and devastating phenomenon that occurs in cancer patients during certain treatments. Unfortunately, tumors that initially respond to chemotherapy eventually become resistant to it, contributing to tumor progression and death. The study reveals that these new cancer "stem" cells, which have not been differentiated into more specific cell types, are capable of multiplying despite being exposed to chemotherapy, while differentiated cells die.
Led by Carlos Cordon-Cardo, MD, PhD, Chair of Pathology, and Josep Domingo-Domenech, MD, PhD, Assistant Professor of Pathology at Mount Sinai, the research team generated cellular models of drug resistance by treating prostate tumor cell lines with increasing doses of the common chemotherapy drugs, including docetaxel. They identified a cell population expressing markers of embryonic development. In addition, these cells displayed cancer stem cell functions, including the capacity to initiate tumor cell growth. Next, the team evaluated human tissue samples of prostate cancer and found that patients with more aggressive or metastatic tumors had more of these cancer "stem" cells.
"This is the first time these so-called cancer stem cells of prostate have been identified as the basis for drug resistance and tumor progression, indicating that they are cancer's 'Achilles Heel,'" said Dr. Cordon-Cardo. "These findings are the culmination of more than six years of innovative research, which has led to the successful unveiling of cancer characteristics that are critical to understanding how the disease works and progresses."