New treatments for diseases such as cancer don’t happen overnight; they require years of investigation, and that journey almost universally begins with showing proof of concept in vitro. A new paper published in Oncotarget describes how common side effects from antibiotics can attack the mitochondria in cancer stem cells. What’s more, this study was inspired by a comment made by senior author Michael Lisanti’s daughter, Camilla. While this method is a long way off from being used as a clinical treatment, it does provide an interesting avenue of research for future studies.
"I was having a conversation with Camilla about how to cure cancer and she asked why don't we just use antibiotics like we do for other illnesses,” Lisanti recalled in a press release. “I knew that antibiotics can affect mitochondria and I've been doing a lot of work recently on how important they are to the growth of tumors, but this conversation helped me to make a direct link."
The current research used five different common classes of antibiotics to treat the stem cells from brain, lung, prostate, ovarian, skin, pancreatic, and breast cancers. Four of the antibiotics were quite successful, as they were able to effectively target the mitochondria in the cancer stem cells, prohibiting their growth and development. Mitochondria are the powerhouse of cells and generate the vast majority of the cell’s energy. Fortunately, the mitochondria within healthy cells were largely unharmed.
"This research makes a strong case for opening new trials in humans for using antibiotics to fight cancer,” Lisanti explained. “Many of the drugs we used were extremely effective, there was little or no damage to normal cells and these antibiotics have been in use for decades and are already approved by the FDA for use in humans. However, of course, further studies are needed to validate their efficacy, especially in combination with more conventional therapies.”
The simplicity and abundant availability of antibiotics make moving forward with this research slightly easier and more encouraging, but there are some points to consider. Yes, antibiotics have already been approved for human consumption by the FDA which should make entering human clinical trials easier, but these in vitro demonstrations do not indicate what the dose may be when dealing with an entire organism, which could be problematic.
Widespread use of antibiotics is leading to dangerous levels of resistance, which could be an unintended side effect as a cancer treatment. Additionally, taking antibiotics for an extended period of time can cause infections of Clostridium difficile, which can be devastating to already immunocompromised cancer patients. Despite these logistical considerations, the researchers are still optimistic as they move forward, as antibiotics have previously been shown to enhance patient survival rates and have several positive qualities as well.
"As these drugs are considerably cheaper than current therapies, they can improve treatment in the developing world where the number of deaths from cancer is predicted to increase significantly over the next ten years," concluded co-author Federica Sotgi.