Researchers at the University of York, the University of Hull and the Castle Hill Hospital in the United Kingdom recently discovered a potential new therapeutic strategy for prostate cancer using low-temperature plasmas (LTPs). The study was published in the British Journal of Cancer and is entitled “Low-temperature plasma treatment induces DNA damage leading to necrotic cell death in primary prostate epithelial cells.”
Prostate cancer is the second most common cancer in men, with almost one million new cases diagnosed every year worldwide. In the United States, it is estimated that 220,800 new cases will be diagnosed in 2015. “Despite continual improvement and refinement, long term treatment for prostate cancer is still recognized as inadequate. In the case of early stage organ confined tumors, patients may be treated with a focal therapy, for example cryotherapy, photodynamic therapy, or radiotherapy,” explained the study’s first author Adam Hirst in a news release.
Radiotherapy or photodynamic therapy are two common treatment strategies for localized prostate cancer, and their action is based on the production of reactive oxygen species (ROS) for cytotoxic effects in cancer cells. However, the side effects experienced by patients and the fact that approximately one-third will experience cancer recurrence after therapy, strongly support the need for new treatment options.
The field of LTPs has rapidly advanced in the last years, being considered a promising potential application in biomedicine, namely in cancer therapy. LTPs are formed by applying a high electric field across a gas using an electrode, breaking down the gas to form plasma and generating a unique environment with high levels of reactive oxygen and nitrogen species (RONS). RONs can then be delivered to a target source, such as cancer cells, becoming a mediator of oxidative damage and cell death in biological systems. Previous studies have shown that LTPs can reduce cancer cell lines’ viability, arrest growth, and induce DNA damage and cell death.
Researchers have now performed a proof-of-principle study to confirm the LTP cytopathic effect on prostate cancer using, for the first time, LTP treatment on primary healthy prostate epithelial cells and prostate cancer tissue cells grown directly from biopsies from a single patient.
The research team found that LTP treatment is cytotoxic for primary prostate cells, inducing considerable DNA damage and a reduction in cell viability. “Through this research we have found that LTPs induce high levels of DNA damage, which leads in turn to a substantial reduction in colony forming ability, and ultimately necrotic cell death. Using clinically relevant, close-to-patient samples, we have presented the first experimental evidence promoting the potential of LTP as a future focal cancer therapy treatment for patients with early stage prostate cancer,” said Hirst.
The research team concluded that LTPs may represent a potential focal therapeutic strategy for patients with organ confined prostate cancer. The team’s next goal is to test LTP treatment on three-dimensional replica tumors.