CHARACTERIZATION OF GENE-EXPRESSION IN CLINICAL LUNG-CANCER MATERIALSBY 2-DIMENSIONAL POLYACRYLAMIDE-GEL ELECTROPHORESIS

Fourteen human lung tumors of various histopathological types were sub jected to two-dimensional gel electrophoresis (2-DE). Samples were pre pared for 2-DE using a nonenzymatic sample preparation (NESP) techniqu e recently established in our laboratory. Variations in the expression of some polypeptides were observed between tumors of different histop athological types. To this end, high expression of beta-tubulin, heat shock proteins 73 and 90, lamin B, and proliferating cell nuclear anti gen (PCNA) were observed in small cell lung carcinomas (SCLC). One pol ypeptide of unknown identity (35 kDa, pI 5.5) was significantly overex pressed in primary lung adenocarcinomas compared with SCLC, squamous c ell lung carcinomas, metastatic lung adenocarcinomas from colon and re ctum, and normal tissue. The amino acid composition of this polypeptid e is presented. In summary, combining the NESP technique and 2-DE is a n effective approach to define tumor-specific markers.