Bloch Finds Defense Mechanism In Human Body May Encourage Growth of Harmful Cancer Cells

Antibodies, the human defense mechanisms which normally fight disease, may actually protect certain types of deadly cancer cells, according to a study published recently by Dr. Kurt J. Bloch, associate in Medicine.

Bloch found that by exposing cancer cells from a mouse to guinea pig antibodies, he could protect the malignant growths from the guinea pig's other defenses. Although he focused his study on a single type of cancer, he said yesterday that the results "could apply equally well to a whole host of tumors in animals and in man."

Bloch determined that the large number of antibodies which an animal produces is responsible for this effect.

When harmful material enters the body of a guinea pig, he said, the animal secretes at least two chemical antibodies, called gamma-1 and gamma-2. The gamma-2 molecule acts rapidly to attach itself to the walls of tumor cells. and with the aid of chemicals in the blood it breaks open the cell membrane, often killing the cancer.

The gamma-1 compound normally serves an entirely beneficial function. In this case, however, it also attaches itself to the cancer cells. But is unable to pierce their outer membranes.

As a result, the cells become covered with thousands of gamma-1 molecules. Thus the other, more effective gamma-2 antibodies can find no place to attach themselves and are totally unable to act. With their coating of inactive gamma-1 antibodies, cancer cells feed, grow and spread.

Bloch has conducted his research so far with isolated cells in test tubes, but he suggests that conditions in the human body may be similar. He is now conducting further research on many different types of animal and human cancers to determine exactly how tumor cells coat themselves with neutralized antibodies.