Identification of a Differential Expression of Two cDNAs between Malignant Mesothelioma and Normal Mesothelial Cells Using the RNA Fingerprint Method

The RNA fingerprint method was used to identify mRNAs that were differentially expressed during the development of human mesothelial cell cancer. We report the isolation of two differentially expressed clones. One clone was expressed in the metastatic mesothelioma cell line M1A and in the malignant mesothelioma cell line M1 and downregulated in normal mesothelial cells. M1 and M1A were derived from a primary and metastatic tumor of the same patient. The other clone was only expressed in normal mesothelial cells. The different expression pattern was confirmed by Northern blot analysis. One clone had a striking sequence homology to the soares pregnant uterus NbHPU homo sapiens cDNA clone. The other clone contained a high sequence homology to the human mRNA for ORF. The biological function of the corresponding genes is unknown. The specificity of expression of the two sequence tags was further examined on different cancer cell lines and normal tissues.