Frequent chromosome 8q gains in human small cell lung carcinoma detected by arbitrarily primed-PCR genomic fingerprinting

The arbitrarily primed-polymerase chain reaction (AP-PCR) genomic fingerpri nting method was applied to detect chromosomal numerical imbalances in 13 s mall cell lung carcinomas (SCLC). Increases and decreases in the intensity of the AP-PCR bands from several chromosomes, representing gains of chromos omes 1, 7, 16, and X, and losses of chromosomes 2, 10, and 22, were recurre nt events in independent tumors. In addition, the most common alterations d etected were increases in signal intensity of three AP-PCR bands derived fr om genomic sequences on chromosome 8q (eight of 13 tumors: 62%). To define whether the 8q gains observed in the AP-PCR analysis include the C-MYC gene at chromosome 8q24 or not, we performed targeted AP-PCR analysis of the C- MYC gene. The C-MYC gene was amplified in five of the eight tumors with gai ns of 8q, but in none of the remaining five tumors in which 8q gains were n ot detected. These results indicate that chromosome 8q gain occurs frequent ly in SCLC and gained regions often, but do not always, include the C-MYC g ene. Moderate increases in copy number of the C-MYC gene and additional gen e(s) in the 8q region appear to be under positive selection during SCLC pro gression. (C) 2000 Elsevier Science inc. AII rights reserved.