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Cloned cells may be new cancer weapon
Cloned cells may be new cancer weapon
Experiments with cloning are creating cells that can aid in cancer detection and perhaps eventually in treatment. Monoclonal antibodies have been used in the laboratory for about eight years. Now they are moving into clinical application. With cloning, scientists can manufacture almost unlimited numbers of identical antibodies that are specific to a particular antigen. Theoretically, these monoclonal antibodies could become selective weapons against tumors, an article in Science (April 16) reports. Clinical work is just beginning. In the most dramatic case, reported from Stanford University School of Medicine, a patient with recurrent 6-cell lymphoma treated with highly purified monoclonal antibodies had been in remission for eight months after treatment ended. The case was described in the March 4 New England Journal of Medicine. Because antibodies would have to be individually produced for each lymphoma case, the treatment may not be practical for most patients, the Science article said. Also, the reason the technique works for this type of cancer is that all the tumor cells are members of a clone and have the same antibody chain on their cell surfaces. Other types of tumor cells do not necessarily have antigens uniqueto them. The same types of antigens may also be present on other types of tumor cells, fetal cells, and normal tissue cells. Thus, it is difficult to clone cells specific only to the tumor. That is a major obstacle in using monoclonal antibodies. Nevertheless, researchers have found
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some strains that seem good enough for clinical use. In addition to treatments for a few lymphoma and leukemia patients, preliminary work is being done in detection of lung, colon, pancreatic, and breast cancer. Investigators hope they may one day be able to use the cloned cells for screening sputum samples from smokers in detecting lung cancer and bloodsamples from personssuspected of having colorectal cancers. Monoclonal antibodies can be tagged with radioactive isotopes and injected. Since they tend to congregate where there is tumor, patterns can be picked up with imaging. In another application, monoclonal antibodies might be used as messengers to deliver cell-killing agents to tumor sites. Researchers at the University of Texas Southwestern Medical School in Dallas have used the cloned cells to kill off tumor cells in the bone marrow of leukemic mice without destroying normal cells. At Johns Hopkins Medical School, investigatorshave treated inoperable liver cancer with radioisotope-tagged cells. A great number of problems remain to be solved, according to Science. One is that scientists do not yet know how to manufacture human-originated monoclonal antibodies. They are relying on those made using mice. Some experts believe the mouse-generated cells could lead to allergic reactions in patients. This could prevent the monoclonal antibodies from reaching their targets. Despite the obstacles, observors expect continuing breakthroughs in the next few years.
AORN Journal, June 1982, V o l 3 5 , No 7
Experiments with cloning are creating cells that can aid in cancer detection and perhaps eventually in treatment. Monoclonal antibodies have been used in the laboratory for about eight years. Now they are moving into clinical application. With cloning, scientists can manufacture almost unlimited numbers of identical antibodies that are specific to a particular antigen. Theoretically, these monoclonal antibodies could become selective weapons against tumors, an article in Science (April 16) reports. Clinical work is just beginning. In the most dramatic case, reported from Stanford University School of Medicine, a patient with recurrent 6-cell lymphoma treated with highly purified monoclonal antibodies had been in remission for eight months after treatment ended. The case was described in the March 4 New England Journal of Medicine. Because antibodies would have to be individually produced for each lymphoma case, the treatment may not be practical for most patients, the Science article said. Also, the reason the technique works for this type of cancer is that all the tumor cells are members of a clone and have the same antibody chain on their cell surfaces. Other types of tumor cells do not necessarily have antigens uniqueto them. The same types of antigens may also be present on other types of tumor cells, fetal cells, and normal tissue cells. Thus, it is difficult to clone cells specific only to the tumor. That is a major obstacle in using monoclonal antibodies. Nevertheless, researchers have found
1424
some strains that seem good enough for clinical use. In addition to treatments for a few lymphoma and leukemia patients, preliminary work is being done in detection of lung, colon, pancreatic, and breast cancer. Investigators hope they may one day be able to use the cloned cells for screening sputum samples from smokers in detecting lung cancer and bloodsamples from personssuspected of having colorectal cancers. Monoclonal antibodies can be tagged with radioactive isotopes and injected. Since they tend to congregate where there is tumor, patterns can be picked up with imaging. In another application, monoclonal antibodies might be used as messengers to deliver cell-killing agents to tumor sites. Researchers at the University of Texas Southwestern Medical School in Dallas have used the cloned cells to kill off tumor cells in the bone marrow of leukemic mice without destroying normal cells. At Johns Hopkins Medical School, investigatorshave treated inoperable liver cancer with radioisotope-tagged cells. A great number of problems remain to be solved, according to Science. One is that scientists do not yet know how to manufacture human-originated monoclonal antibodies. They are relying on those made using mice. Some experts believe the mouse-generated cells could lead to allergic reactions in patients. This could prevent the monoclonal antibodies from reaching their targets. Despite the obstacles, observors expect continuing breakthroughs in the next few years.
AORN Journal, June 1982, V o l 3 5 , No 7