Nanoparticle Therapy May Kill Liver Cancer Cells

An experimental nanoparticle therapy that combines low-density lipoproteins (LDL) and fish oil preferentially kills primary liver cancer cells without harming healthy cells, University of Texas (UT) Southwestern Medical Center researchers report.

"This approach offers a potentially new and safe way of treating liver cancer, and possibly other cancers," says study senior author Ian Corbin, PhD, an assistant professor in the Advanced Imaging Research Center and of Internal Medicine at UT Southwestern. "The method utilizes the cholesterol carrier LDL combined with fish oil to produce a unique nanoparticle that is selectively toxic to cancer cells."

The study is published in the February 2016 issue of the journal Gastroenterology.

Primary liver cancer, or hepatocellular carcinoma, is the sixth most prevalent type of cancer and third-leading cause of cancer-related deaths worldwide, according to the National Cancer Institute. Incidence of the disease is rising in the United States, principally in relation to the spread of hepatitis C virus infection.

Although several studies have reported an association between cancer prevention and omega-3 fatty acids, there have not been any studies showing benefits of omega-3 fatty acids against established tumors, Corbin says. "Our study suggests established tumors would need to be exposed to higher concentrations of omega-3 fatty acids than could be achieved through diet," he adds.

In the UT Southwestern study, conducted in rats, the newly formulated LDL-DHA nanoparticles were injected into the artery leading to the liver, the site of the cancer, he says.

"This research study clearly demonstrates the anticancer potential of omega-3 fatty acids," Corbin says, adding that while the study showed significant cancer cell toxicity, it's too soon to tell whether the approach is able to kill every cancer cell. Future experiments will examine that question, as well as whether the LDL-DHA strategy improves long-term cancer survival.

"We knew that cancer cells like to take up LDL in order to acquire cholesterol and other lipids to help build their cell membranes as they proliferate. So what we have here is a classic example of a Trojan horse. The cancer cell thinks it's getting cholesterol to provide the nutritional building blocks needed to grow and proliferate. Instead, it gets a payload of fish oil in the form of LDL-DHA nanoparticles that are selectively toxic to cancer cells without harming normal liver cells," he says.

The researchers gave rats with liver cancer either the LDL-DHA nanoparticles or control treatments of LDL without DHA, which were expected to have no effect. After three days, the tumors in controls had grown large and developed a good blood supply, which is essential to cancer growth. In contrast, the LDL-DHA rats had smaller, pale tumors with poor blood supply. In fact, more than 80% of their tumor cells were dying, the researchers report.

"In conclusion, our study demonstrates that LDL-DHA nanoparticles have potent anticancer activity," they write.

— Source: UT Southwestern Medical Center