Amplification and expression of different myc ‐family genes in a tumor specimen and 3 cell lines derived from one small‐cell lung cancer patient during longitudinal follow‐up

In a small‐cell lung carcinoma (SCLC) tumor specimen as well as in 3 cell lines derived from SCLC biopsies obtained from the same patient at successive times during the clinical course, either the N‐myc gene or the c‐myc gene appeared to be amplified and expressed. The initial tumor specimen, a lymph‐node metastasis, was amplified for N‐myc , as was the cell line GLC‐14 derived from this metastasis. The cell lines GLC‐16 and GLC‐19, derived from recurrent primary tumor biopsies after a complete remission, were amplified for c‐myc . This finding implies independent amplification events and supports the idea that the amplification of myc genes is probably a secondary event correlated with tumor progression. Although all 3 cell lines could be classified as classic SCLC cell lines according to their histological characteristics, GLC‐16 and GLC‐19 clearly possess, in their c‐myc amplification and derivation from therapy‐resistant tumor cells, features of variant SCLC lines. This may question the significance of the classic/variant classificatio