Antibody Potentially Kills Cancer Cells, Leaves Healthy Cells

An antibody derived from the human immune system may kill cancer cells with less harm to patient.

Researchers in a recent study were able to create an antibody derived from the human immune system that attacks cancer cells, but leaves other cells unharmed.

The study, published by Cell Reports, found that the antibody is able to dismantle part of the cancer cell defense system, and then uses several methods to attack the cell.

"This is the first completely human-derived antibody developed as an anti-cancer therapy, which is very different from other immunotherapy approaches," said senior author Edward F. Patz, Jr, MD.

The team of researchers noticed that some lung cancer patients had early-stage tumors that never progressed. Patients with more lethal tumors had a presence of antibodies against complement factor H (CFH). CFH is known to protect cells from an immune attack.

CFH prevents the deposit of a complement C3b protein on the cell surface. Complement C3b starts the degradation of the cell membrane, leading to cell death.

Once researchers were able to identify the antibody for CFH, they were able to evaluate how the immune response could be used as a cancer treatment. Researchers needed to create an antibody that contained the same part of CFH as the antibodies seen in early-stage cancer patients.

Researchers gathered white blood cells from CFH antibody-producing cancer patients. According to the study, they then isolated and cloned the antibody genes from immune cells that make specific antibodies.

This process allowed researchers to create mature antibodies that were able to recognize the region of CFH targeted by patient’s immune systems, resulting in the attack of cancer cells while leaving healthy cells unharmed. Researchers tested the antibodies in lung, gastric, and breast cancer cell lines in both lab dishes and in mice.

It was observed that the antibodies caused cell death without any noticeable side effects, and even triggered an additional immune system response since the damaged cells sent signals to recruit lymphocytes, thus creating a more fatal immune system attack.

"We believe it might be this additional cellular response that could potentially have the most profound impact on cancer outcomes long-term,” Dr Patz concluded. “This could represent a whole new approach to treating cancer, and it's exciting because the antibody selectively kills tumor cells, so we don't have significant side effects to achieve tumor control. We believe we can modulate the immune response and let the body's own immune system take over to either kill the tumor or keep it from growing."