The liver is an important organ that is responsible for removing toxins and other chemical waste products from the blood before excretion. Since blood will pass through the liver, it allows for easy access to cancer cells traveling in the bloodstream.
Primary liver cancer, or hepatocellular carcinoma, begins in the cells of the liver, and it accounts for around two percent of all cancers in the U.S. It is estimated that about 70% of all liver cancer cases will die in 2016.
That being said, a new and safe treatment for liver cancer, and possibly other cancers, may be on the horizon. In a new study published in the journal Gastroenterology, researchers from UT Southwestern Medical Center have found that an experimental nanoparticle therapy can kill primary liver cancer cells in rats without harming the healthy cells in the body. The nanoparticle therapy uniquely combines the cholesterol carrier low-density lipoprotein (LDL) and fish oil that is selectively toxic to cancer cells.
It is important to note that an editorial in the same Gastroenterology issue mentioned that there are limitations with drug treatments for liver cancer. The UT Southwestern study showed remarkable results that may potentially lead to a shift in liver cancer treatment from ablation, liver transplantation, and partial liver surgery.
Fish oils are particularly high in the omega-3 fatty acid called docosahexaenoic acid (DHA). Previous studies have linked omega-3 fatty acids with liver cancer protection abilities in hepatitis B or C patients. However, there haven’t been any studies supporting omega-3 fatty acids for already present tumors. But, the current study finds that high concentrations of omega-3 can fight tumors.
“The research study clearly demonstrates the anticancer potential of omega-3 fatty acids,” explained senior study author Dr. Ian Corbin, who is an assistant professor of internal medicine at UT Southwestern.
Dr. Corbin led a multidisciplinary team with specialization in the fields of nutritional science, cancer biology, lipid biochemistry, advanced imaging, and biotechnology. As a result, they were able to create the LDL-DHA nanoparticle formulation. The work is thought to expand on the UT Southwestern collaboration of Dr. Joseph Goldstein and Dr. Michael Brown that led to a Nobel Prize in 1985. They would discover the LDL receptor and build on the understanding of how the protein functions. This led to the development of cholesterol-lowering statin drugs.
While trying to understand how LDL receptors work, Dr. Goldstein and Dr. Brown conducted experiments where they removed cholesterol content from the LDL and then added other cholesterol molecule types. In the current study, Dr. Corbin and his team instead injected the combination of LDL and DHA into the livers of rats for a possible cancer treatment.
When cancer cells multiply they are thought to acquire LDL and other lipids. The researchers noted this is a version of a Trojan horse.
“The cancer cell thinks it’s getting cholesterol to provide the nutritional building blocks needed to grow and proliferate,” added Dr. Corbin. “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.”
The researchers also gave the rats a control treatment of LDL without DHA. The control was expected to have no effect, but instead it lead to signs of tumor growth, including a good blood supply. On the other hand, the LDL-DHA formula killed over 80% of the cancer cells in the rat livers, while blood supply was poor.
Although the study found that the LDL-DHA formula reduced liver tumor growth, it still wasn’t clear whether the therapy would kill every cancer cell. In future studies, the research team will look to determine whether every cancer cell is killed, and whether the efficacy of the LDL-DHA therapy can improve the long-term cancer survival rate.
Sources for Today’s Article:
Wen, X., et al., “Hepatic Arterial Infusion of Low-Density Lipoprotein Docosahexaenoic Acid Nanoparticles Selectively Disrupts Redox Balance in Hapatoma Cells and Reduces Growth of Orthotopic Liver Tumors in Rats,” Gastroenterology, 2016; 150(2): 488, doi: 10.1053/j.gastro.2015.10.008.
“Nanoparticle therapy that uses LDL and fish oil kills liver cancer cells,” UT Southwestern Medical Center Newsroom web site, February 8, 2016;