Scientists identify the 'Achilles' heel' of cancer

Researchers at the Mount Sinai School of Medicine have identified a subpopulation of cells which display cancer stem cell properties, are resistance to chemotherapy and participate in tumour progression.

Resistance to chemotherapy is a frequent and devastating phenomenon that occurs in cancer patients during certain treatments.

Unfortunately, tumours that initially respond to chemotherapy eventually become resistant to it, contributing to tumour progression and death, the researchers said.

The study showed 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.

The research Led by Dr Carlos Cordon-Cardo and Josep Domingo-Domenech generated cellular models of drug resistance by treating prostate tumour cell lines with increasing doses of the common chemotherapy drugs, including docetaxel.

They identified a cell population expressing markers of embryonic development.

These cells displayed cancer stem cell functions, including the capacity to initiate tumor cell growth.

The team then evaluated human tissue samples of prostate cancer and found that patients with more aggressive or metastatic tumours 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 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," he said in a statement.

The study also defines a new therapeutic strategy for patients with prostate cancer, consisting of a combination of standard chemotherapy and two pharmacological agents that inhibit key signaling pathways associated with embryonic development and cell differentiation.