Non-Technical Abstract 
Non-Technical Abstract 
Autologous Bone Marrow Transplantation (ABMT) is a method of treating breast cancer by giving 
patients very high doses of chemotherapy and then rescuing them with their bone marrow cells that 
have been removed and frozen. In this study, patients will be treated initially with standard doses of 
chemotherapy to cause a remission of their breast cancer. Then, blood cells which are capable of 
rebuilding patients’ bone marrows will be removed from the patients’ bloodstream and bone marrow. 
Seventy percent of these blood cells will be frozen directly and 30% will be used to separate the 
“stem” cells, those cells thought to be the forebearers of all other blood cells. These stem cells will be 
cultured with a disabled virus which carries genetic material referred to as the multidrug resistance 
gene (MDR-1). The vims transfers the MDR-1 gene into a portion of the patient’s stem cells. The 
purpose of putting the MDR-1 gene into the patients’ stem cells is to try to make these blood cells and 
their offspring resistant to the toxic effects of chemotherapy. The MDR-1 protein (Pgp) that is made 
from the MDR-1 gene makes cells resistant to chemotherapy by pumping the drug out of cells before 
the drug is able to kill the cell. 
Patients are then treated with very high doses of ICE (ifosfamide, carboplatin, and etoposide) 
chemotherapy and then the frozen blood cells as well as the MDR-1 blood cells are given back to the 
patient through a catheter in a vein. It is hoped that the MDR-1 stem cells will contribute to the 
rebuilding of patients’ bone marrows following the high-dose chemotherapy. Samples of patients’ 
bone marrows and peripheral blood cells will be obtained at several points after the bone marrow 
recovers to follow the course and life span of the cells containing the MDR-1 vims. Patients who still 
have evidence of breast cancer or whose breast cancer returns after ABMT will be treated with taxol, a 
chemotherapy drug that is pumped out of cells by the MDR-1 protein. We will again follow patients’ 
blood counts closely to determine whether the number of blood cells that contain the MDR-1 gene 
increases in response to the chemotherapy. Patients will be treated with taxol for as long as there is 
evidence of a beneficial effect against their tumor. 
Recombinant DNA Research, Volume 18 
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