Fighting Ovarian Cancer with Arsenic

Arsenic is typically understood as a poison, but it could be extremely helpful in fighting cancer. Ovarian cancer affects over 22,000 women in the United States on a yearly basis. It ranks 5th in cancer deaths among women, making it deadlier than any other cancer of the female reproductive system.

To date, the main treatment for ovarian cancer is surgery, which involves removing as much of the tumor as possible, followed by chemotherapy. Typically, a combination chemotherapy of a type of chemo drug called a platinum compound (usually cisplatin or carboplatin) and another chemo drug called a taxane (such as docetaxel or paclitaxel) works best as a first chemotherapeutic approach for the disease.

Improving the effectiveness of cisplatin

For the last 50 years, cisplatin has been the most active chemotherapeutic drug used to treat ovarian cancer and the survival rate for women with the disease can be defined by the tumor response to the drug. The tumors that express platinum-resistance generally have poor prognosis and, although a majority of patients with ovarian cancer respond to platinum combination chemotherapy, many will develop disease that becomes resistant to cisplatin, and they will ultimately succumb to it.

As a result, it has been found that improving the effectiveness of cisplatin can have a major impact in the battle against ovarian cancer. Tom O’Halloran, a Professor in Chemistry and Molecular Biosciences and a well-known expert on inorganic compounds, believes that certain inorganic compounds and elements may be used to kill cancer cells – such as arsenic.

The role of arsenic in cancer

Arsenic is a naturally occurring element that can be found in water, soil, and air. It can also be released into the environment by certain industrial and agricultural processes. Arsenic comes in two forms – organic and inorganic. Organic compounds are found in some food, such as fish, while inorganic compounds tend to be toxic and linked to an increased risk of cancer.

Although arsenic is commonly known for its use as a poison, O’Halloran believes that it can be used as a potential cancer drug. Yet, traditional methods used to deliver arsenic have not been successful in solid tumors in the ovaries, lungs, breasts, and others areas of the body. “What limits arsenic’s broader application in cancer is its toxicity. So, we asked whether we could control that toxicity but still allow its destructive effect to manifest only in cancer cells,” said O’Halloran.

O’Halloran and his team began their research by inserting insoluble particles of arsenic into a liposome, which is a tiny vesicle of fat, thereby creating what they named a “nanobin.” When injected into the blood, the nanobins release arsenic only once they reach cancer cells and the healthy cells remain unharmed.

Yet, how is this possible?

Read on to learn more about how exactly arsenic targets cancer cells.