Tissue microarrays for gene amplification surveys in many different tumor types

Gene amplifications are common in many different tumor types and may confer diagnostic, prognostic, or therapeutic information for patient management. Tedious experiments are often required to determine which tumor types have amplifications of a specific oncogene, To facilitate rapid screening for m olecular alterations in many different malignancies, a tissue microarray co nsisting of samples from 17 different tumor types was generated. Altogether , 397 individual tumors were arrayed in a single paraffin block. To determi ne whether results from the literature can be reproduced on minute tissue s amples (diameter, 0.6 mm), amplification of three extensively studied oncog enes (CCND1, CMYC, and ERBB2) was analyzed in three fluorescence in situ hy bridization experiments from consecutive sections cut from the tissue micro array. Amplification of CCND1 was found in breast, lung, head and neck, and bladder cancer, as well as in melanoma, ERBB2 was amplified in bladder, br east, colon, stomach, testis, and lung cancer. CMYC was amplified in breast , colon, kidney, lung, ovary, bladder, head and neck, and endometrial cance r. These results confirm and even extend existing data in the literature on such amplifications. In summary, we applied three fluorescence in situ hyb ridization experiments to analyze amplifications of three oncogenes in thre e x 397 tumors within a week. This demonstrates the power of using minute a rrayed tissue specimens for tumor screening.