Researchers at the University of Cincinnati Academic Health Center recently published in the journal Molecular Cancer Therapeutics their findings on a therapeutic agent based on SapC-DOPS technology for lung cancer treatment. The study is entitled “SapC–DOPS Nanovesicles as Targeted Therapy for Lung Cancer.”
According to the American Cancer Society, lung cancer is the most common cancer and the primary cause of cancer-related deaths in the United States and worldwide for both men and women. The U.S. will have an estimated 221,000 new cases and 158,000 deaths in 2015 alone. Cigarette smoking is the main risk factor for the development of the disease, followed by occupational and environmental exposure to pollutants.
“I partnered with scientists at Nanjing Medical University in China for this research, as lung cancer in China is a major health issue,” said Dr. Xiaoyang Qi, from the University of Cincinnati and the study’s senior author, in a news release. “As reported by the International Agency for Research on Cancer, more than half of lung cancer deaths caused by air pollutants worldwide occurred in China and other East Asian countries.”
In this study, researchers assessed the in vitro and in vivo efficacy of a biotherapeutic agent based on two natural cellular components, a lysosomal protein (Saposin C, SapC) and a phospholipid (dioleoylphosphatidylserine, DOPS) that can be combined and assembled into nanovesicles, named SapC–DOPS. These SapC-DOPS have been previously shown to have selective antitumor activity, causing cell death in several types of cancer, such as brain, prostate, breast, skin, blood and pancreatic cancer, without affecting normal cells and tissues.
“Standard treatment options for lung cancer, including chemotherapy, radiation and surgery, have undesirable side effects that impact the quality of life of the cancer patient, which is why the targeted use of SapC-DOPS could be so beneficial,” explained Dr. Qi.
Regarding liposomal formulations, Dr. Qi said, “Compared with non-encapsulated, free drugs, they provide improved biocompatibility and targeted delivery. Despite promising results in preclinical models of lung cancer and many other cancer types, only a few non-targeted liposomal formulations have been approved for cancer treatment by regulatory agencies. Clinical trials are under way to evaluate some of these in lung cancer patients. However, so far, these liposomes have been shown to be less effective when compared with free drug administration, which is why the SapC-DOPS research is promising as a targeted treatment for lung cancer.”
SapC–DOPS target phosphatidylserine (PS), a phospholipid usually exposed in the surface of cancer cells. Researchers used SapC-DOPS to target lung tumor cells in both human cell cultures and in animal models. “Using a double-tracking method in live models, we showed that the nanovesicles were specifically targeted to the tumors. These data suggest that the acidic phospholipid PS is a biomarker for lung cancer, as it has been found to be for pancreatic and brain tumors in previous studies, and can be effectively targeted for therapy using cancer-selective SapC-DOPS nanovesicles.”
“We observed that the nanovesicles selectively killed human lung cancer cells, and the noncancerous, or untransformed cells, remained unaffected,” observed Dr. Qi. Animal models treated with SapC-DOPS also exhibited a halt in tumor growth, where tumors shrank or disappeared.
“Our results show that SapC-DOPS could be a promising treatment option for lung cancer worthy of further clinical study,” concluded Dr. Qi. The team also suggests that this therapeutic agent could represent a key treatment for a broad range of different cancers.
