Genes regulating the sensitivity of solid tumor cell lines to cytotoxic agents: a literature review

In order to review gene alterations associated with drug responses in vitro to identify candidate genes for predictive chemosensitivity testing, we selected from literature genes fulfilling at least one of the following criteria for the definition of 'in vitro chemosensitivity associated gene': (i) alterations of the gene can be identified in human solid tumor cell lines exhibiting drug-induced resistance; (ii) transfection of the gene induces drug resistance; (iii) down-regulation of the gene increases the drug sensitivity. We then performed Medline searches for papers on the association between gene alterations of the selected genes and chemosensitivity of cancer cell lines, using the name of the gene as a keyword. A total of 80 genes were identified, which were categorized according to the protein encoded by them as follows: transporters (n = 15), drug targets (n = 8), target-associated proteins (n = 7), intracellular detoxifiers (n = 7), DNA repair proteins (n = 10), DNA damage recognition proteins (n = 2), cell cycle regulators (n = 6), mitogenic and survival signal regulators (n = 7), transcription factors (n = 4), cell adhesion-mediated drug resistance protein (n = 1), and apoptosis regulators (n = 13). The association between the gene alterations and chemosensitivity of cancer cell lines was evaluated in 50 studies for 35 genes. The genes for which the association above was shown in two or more studies were those encoding the major vault protein, thymidylate synthetase, glutathione S-transferase pi, metallothionein, tumor suppressor p53, and bcl-2. We conclude that a total of 80 in vitro chemosensitivity associated genes identified in the literature are potential candidates for clinical predictive chemosensitivity testing.