Analysis of Cellular Oncogene Amplification in Human Lung Cancers

Twenty-six lung cancer tissues from operation or autopsy and eight lung cancer cell lines were examined for an amplification of the ten different cellular oncogenes, c-myc, N-myc, L-myc, c-erbB-1, c-erbB-2, c-fos, v-sis, c-H-ras, v-K-ras, and N-ras, by the Southern blot hybridization. In small cell lung cancer(SCLC), one SCLC tissue(13-1) out of four SCLC tissues and one SCLC cell line contained three fold amplifications of the L-myc oncogene. In non-SCLC, one adenocarcinoma cell line(SLO51) and one large cell carcinoma cell line(SLC-30) showed an amplification of the c-myc oncogene at four fold normal amount and twenty fold amplifications of the c-erbB-1 oncogene respectively, out of twenty-two non-SCLC tissues and seven non-SCLC cell lines. Other lung cancer tissues and cell lines did not show any detectable amplifications or rearrangements of oncogenes. These results suggest that an amplification of the studied oncogenes may not always be associated with carcinogenesis even in lung cancer cell lines. Compared with lung cancer cell lines, the frequency of an amplification of oncogenes in lung cancer tissues was low, especially in non-SCLC tissues.