Better odds for lung cancer patients

Medical scientists are constantly looking for a cure to the world’s deadliest diseases. One of these diseases holds the Center for Disease Control’s number two deadliest disease title: cancer. Of the different types of cancer, lung cancer is one of the most common and has a death rate of more than 150,000 people per year. UC Davis researchers aim to change that.

Recently, a team of UC Davis researchers found a protein on the surface of lung cancer cells that could prove to be useful in developing effective cancer treatments.

“We have been studying proteins on the surface of leukocytes for years,” said Dr. Joseph Tuscano, co-principal investigator of the study and professor of hematology and oncology in the UC Davis Department of Internal Medicine. “We developed antibodies against [the protein] to treat cell lymphomas.”

Leukocytes are white blood cells that defend the body against diseases. There are five different types of leukocytes, including B cells. Lymphomas are cancers that affect the immune system, most commonly found in lymph nodes.

The protein the researchers found is called CD-22, a sugar-binding transmembrane protein. This means it binds to specific sugar molecules and goes from one side of a membrane to the other. CD-22 is typically found on mature B cells. Initially, researchers thought CD-22 was only found on B cells, but they recently discovered that it also appears on lung cancer cells. Additionally, they found other lung cancer cell lines expressed CD-22.

The discovery was even more exciting and significant because there was already an antibody developed that targeted CD-22. The monoclonal antibody, HB22.7, was tested in mice and found to treat non-Hodgkin’s lymphoma, the cancer of lymph tissue. Monoclonal antibody therapies are very effective because they destroy cells containing the antigen, in this case, CD-22.

“Currently, lung cancer is most commonly treated in a ‘stage-dependent’ manner. More recently, there has been a push to develop targeted therapies. Targeted treatments are directed towards specific genetic or molecular defects found on cancer cells,” said Dr. Raj K. Batra, an associate professor of medicine and researcher for the UCLA Jonsson Cancer Center.

“There are three main targeted interventions currently approved for treating lung cancer … in general, these drugs occasionally or often yield a dramatic response, but unfortunately, these responses are of limited duration.”

After testing HB22.7 on mouse models for lung cancer, the treatment reduced tumor growth in the treated mice by about 50 percent. Lung cancer metastasis, the cancer cells’ ability to circulate through the bloodstream and implant in other organs, was studied as well, using the mouse models. There was very little evidence of any tumor growth and the growth that was spotted was insignificant. Also, the treated mice had a much higher survival rate than the untreated mice; 90 percent of the treated mice were still alive at the end of the 84-day trial.

“It has been an exciting time recently for lung cancer research,” said Dr. Edward B. Garon, assistant clinical professor and director at the Thoracic Oncology Program at the David Geffen School of Medicine at UCLA. “We have been in a situation where we have been able to start working towards personalizing care for a percentage of patients … our ability to treat the disease is [overall] more effective.”

In medical research, many fields of study overlap and together bring about solutions to common problems. Cancer research is no different.

“We are looking into prostate cancer and other cancer types,” Tuscano said. “Research in one area is often beneficial to many areas … [This] research may help us understand many cancers or many diseases.”

The research will aid in the battle against life-threatening cancers of all types and will hopefully send cancer to the bottom of the Center for Disease Control’s deadliest disease list.

NICOLE NOGA can be reached at science@theaggie.org.