Discrimination of human lung neoplasm from normal lung by two target genes

Simple tools for discrimination of lung tissues can be useful in a fast machine-aided diagnosis, for example, by tumor-specific microarrays. We demonstrate that an easy ratio technique, based on the expression levels of only two genes differentially expressed in lung tumor and normal lung samples, allows discrimination of normal and neoplastic lung with a sensitivity of 100% and specificity of 90.5%. DNA microarray analysis of 99 lung tumor samples and 15 normal lung tissues revealed that receptor for advanced glycation end products (RAGE) mRNA is reduced fourfold (p = 7.8 x 10(-11)) and cyclin-B2 mRNA is upregulated twofold (p = 5.9 x 10(-18)) in lung carcinoma compared with normal lung. The microarray-calculated expression ratio of RAGE to cyclin-B2 was used in polymerase chain reaction analysis of 84 independent blinded samples to discriminate tumor and corresponding normal lung tissues. In 94.7% of the samples this quotient correctly distinguished non-small cell lung cancer from normal lung tissue, suggesting the RAGE/cyclin-B2 quotient as a potential means for diagnosis of lung cancer.