Antibody may reduce or eliminate tumors

Mar 17 2006

San Diego State University researcher Roger Sabbadini has brought scientists one step closer to finding a cure for cancer with the creation of an antibody that hinders the growth of tumors by preventing blood vessel formation.

As published in the March 14 issue of Cancer Cell, a leading oncology journal, Sabbadini and his research team have created an antibody, Sphingomab, that can be used as a drug to reduce the size of tumors in experimental animal models of human cancer. The antibody works as a molecular sponge by soaking up sphingosine-1-phosphate (S1P), a molecule that has been proven to stimulate the growth of new blood vessels. S1P has been identified as a mediator of tumor cell proliferation and protector of tumor cells from chemotherapy drugs. By neutralizing S1P, the Sphingomab antibody inhibits the new blood vessel formation that tumors require to thrive, a process called 'tumor angiogenesis.'

The group's research tested the antibody in mice tissue implanted with drug-resistant human breast, ovarian and lung cancer cell lines, as well as a mouse skin cancer cell line. In ovarian cancer models, two of five subjects displayed no tumors, and three subjects had tumors with 68 percent less volume than those in the control group. Tumors were reduced by about 60 percent in volume in lung and breast cancer models.

"This groundbreaking research provides new hope for therapeutic treatments for forms of cancer that are resistant to current therapeutics," Sabbadini said. "The Sphingomab antibody is especially powerful as it is shown to prevent tumors from a variety of cancers, as opposed to being effective against only one type of cancer."

Sabbadini's previous sphingolipid research led to the founding of Lpath Inc.

"It has become a dream of mine to be a part of great anti-cancer research, as my mother is a cancer survivor," said Bradley Sibbald, a master's degree candidate in SDSU's molecular biology program and a co-author of the study. "With the creation of this antibody, I now have a new investigative tool to help cure cancers with liquid tumors, which is the focus of my current research."

The research team was primarily comprised of current and former students of SDSU, as well as researchers affiliated with Lpath Inc. Besides Sibbald, other authors of the study include Barbara Visentin, John Vekich, Amy Cavalli and Kelli Moreno, all former SDSU students. Other contributing researchers include Rosalia Matteo and William Garland, both with Lpath Inc., and University of Texas Anderson Cancer Center researchers Shuangxing Yu, Yiling Lu, Hassan Hall, Vikas Kundra and Gordon Mills.

Sabbadini will present the team's findings at the annual conference for the American Association of Cancer Researchers, April 1 - 5, in Washington D.C. Additionally, Lpath Inc. is preparing an application to the U.S. Food and Drug Administration for approval to use the antibody for human clinical trials.

Lpath is a theranostics company focused on bioactive signaling lipids as targets for treating and diagnosing important human diseases. For more information on Lpath, visit www.lpath.com.