Anticancer drugs alkylating agents

J. A. Hartley, Selectivity in alkylating agent-DNA interactions, in Molecular Aspects of Anticancer Drug-DNA Interactions Vol. 1 (Eds. S. Neidle, M. Waring), CRC Press, Boca Raton, FL, 1993, 1. 

Anticancer drugs act on cells in active proliferation and may interfere with a specific phase of the cell cycle or act independently from it. Some of these drugs are naturally occurring compounds, identified in plants or microorganisms, some are synthetic chemicals. Among the major classes of chemotherapeutics include antimetabolites, alkylating agents, inhibitors of the... 

Clinical Use. Cyclophosphamide (Cytoxan, Neosar) is an anticancer alkylating agent that is commonly used in a variety of neoplastic disorders (see Chapter 36). This drug may also be helpful in suppressing the immune response in certain autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis.12 43 High doses of cyclophosphamide are also used to prevent tissue rejection in patients receiving bone marrow transplants and other organ transplants. 

Chemotherapy agents, such as DNA alkylators (see Chapter 6), have traditionally been administered intravenously because of their high chemical reactivity and low bioavailability. During the past decade, a new class of oral anticancer drug, the tyrosine kinase inhibitors, has been developed. These inhibitors bind membrane-bound tyrosine kinase-linked receptors (TKLR) (see Chapter 5). 

The correct choice = E. Tamoxifen forms a complex with the estrogen receptor. Procarbazine inhibits monoamine oxidase, an enzyme required to metabolize tyramine found in fermentative sources, such as cheese and some wines. X-irradiation is effective in eradicating leukemic cells which have found sanctuary in the CNS. Many anticancer drugs are mutagenic and carcinogenic, particularly the alkylating agents. 

The sulfur mustards gave rise to the nitrogen mustards, which are less reactive alkylating agents that are used as anticancer drugs. Nitrogen mustards alkylate DNA, which prevents its reproduction and ultimately kills the cells. 

---