Expression of cytochrome P450 in lung tumor.

Cytochrome P450 (CYP450) enzymes have the capability of playing key metabolic roles in several aspects of cancer as a consequence of their unusually broad substrate specificities. CYP450 are also prominent players in the metabolism of anticancer therapeutic drugs, enhancing or diminishing the efficacy of the drugs depending on whether the drug or its metabolites are efficacious. As CYP450 enzymes are also found in lung tissue, lung metabolism can be of importance to the bioactivation of some anticancer agents. The presence of individual forms of CYP450 has been investigated in lung tumor to determine whether intra-tumor metabolism of anticancer agents by CYP450 could occur and thus influence the response of tumor to these agents. Differences in drug metabolism between normal and cancerous lung tissue have been shown to exist, therefore; the variable expression of CYP450 between tumor and normal tissue can provide a basis for selective sensitivity of tissue to anticancer drugs, thereby localizing drug actions to tumor. This review gives a detailed picture of the expression of CYP450 in lung tumor and the role of this enzyme in lung tumor in the fate of anticancer drugs.