New insights into how cancer cells can maintain resistance to chemotherapy

Royal College of Surgeons in IrelandJul 12 2011

Researchers from the Royal College of Surgeons in Ireland (RCSI) have conducted a study which reveals new insights into how cancer cells can maintain a resistance to chemotherapy resulting in cancer relapse. The findings may contribute to improved cancer treatments and better outcomes for patients.

In chemotherapy treatment, anti-cancer drugs are used to kill cancer cells. These drugs trigger a process of programmed cell death (apoptosis) and also impair the function of mitochondria; which are the parts of the cell that regulate the cell's energy production and are essential in maintaining the balance of water and ions, which include substances such as minerals and salts, in the cell (osmotic homeostasis). While apoptosis and impairment of mitochondrial function both lead to cell death, some cancer cells manage to evade both processes to survive the chemotherapy treatment. The study by the RCSI team is the first to reveal the mechanisms by how these cells survive.

The research has shown that chemotherapy resistance is due to a difference in the metabolism which exists in cancer cells compared to normal human cells. In addition to producing energy in the mitochondria, cancer cells can also energy by using glucose in a process known as glycolysis. While it was previously known that this process of glycolysis can restore energy levels in cancer cells being targeted by chemotherapy, this study has revealed that glycolysis also helps to restore mitochondrial function which means that the cancer cells may continue to function following the treatment.

Dr Heinrich Huber, Senior Lecturer at the Department of Physiology and Medical Physics, RCSI commented: "Our findings show that when cancer cells are exposed to elevated glucose levels, mitochondrial function can be restored and osmotic homeostasis can be maintained which contributes to resistance to chemotherapy. Therefore, we have found that in order for cancer treatments to be effective, they must target the cancer cell's ability to produce energy by using glucose within its fluids as well as destroying the mitochondria."

"It is also important that glucose levels in patients are monitored because this can be a factor in resistance to treatment. We hope that our research may inform new potential treatments for cancer." Dr Huber concluded.