Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: FRIDAY, March 5, 1993 TAG: 9303050052
SECTION: NATIONAL/INTERNATIONAL PAGE: A-5 EDITION: METRO
SOURCE: Associated Press
DATELINE: WASHINGTON LENGTH: Medium
COLON CANCER TARGETED WITH `SMART BOMB' CELLS
Human immune cells linked with special antibodies have turned into biological "smart bombs" that target and kill colon cancer cells, according to researchers.Dr. Hiroshi Takahashi of Massachusetts General Hospital Cancer Center in Charlestown, Mass., said Thursday that although the method has been tested only in mice, it could develop into a powerful new therapy for human cancers.
A report on the study was to be published today in the journal Science.
Takahashi said the technique uses powerful killer cells that are present in the human immune system.
The cells, called lymphokine-activated killer cells, or LAK, have been shown to be extremely toxic to colon cancer tumors in test tube experiments. In clinical trials with patients, however, Takahashi said the cells mount only a weak attack on the cancer.
Takahashi said it was thought that if the LAK could be directed to target tumor cells more directly, it could be a powerful cancer killer. One way to do that, he said, would be to link LAK with an antibody that naturally seeks out cancer cells.
To test the idea, Takahashi and his colleagues infected laboratory mice with human colon cancer cells. They then attached human LAK cells to a laboratory-made antibody that naturally seeks out and attaches to colon cancer cells.
One group of mice infected with human colon cancer was injected with untreated LAK cells. Another group of mice was injected with the LAK cells that had been linked with the antibody.
The result was a reduction in tumors of up to 80 percent among the mice receiving the LAK-plus-antibody injections, Takahashi said.
Survival time for mice receiving the LAK-antibody injections was almost twice that of untreated mice, he said. The median survival time for untreated mice was 30 days, while mice that received four injections of the LAK-antibody cells had a median survival time of 54 days.
Takahashi said the study proved that it is possible to link the LAK cells with antibodies that will carry the powerful killer cells directly to cancer cells.