DNA amplification on chromosome 6p12 in non small cell lung cancer detected by arbitrarily primed polymerase chain reaction

Abstract

Gene amplification is clearly an important aspect of tumour growth and development and has prognostic significance in certain tumours. The identification and genetic characterisation of new areas of amplification in human malignancy remains an important goal in understanding the underlying genetic lesions within these tissues. In the present work, arbitrarily primed-PCR (AP-PCR) has been applied to detect and characterise amplified DNA fragments in human non small cell lung cancer (NSCLC). Our results show that gains of genomic sequences occur at high frequency (64% of all genomic changes analysed). Moreover, we succeeded in detecting a genomic sequence that is highly amplified in one of the tumours analysed. The amplification intensity of this DNA fragment was also increased in 29 (45%) of the 65 NSCLC patients from our study. The amplified DNA fragment was isolated and identified as a 600 bp sequence mapped to chromosome 6p12. This sequence did not show significant homology with known human DNA sequences. Interestingly, a gene related to cancer processes, the pim-1 oncogene, is placed neighbouring to this region on chromosome 6. Survival studies revealed that disease-free interval of NSCLC patients was shorter in patients bearing the amplified sequence (p = 0.05 by the Breslow test). Our findings suggest that the amplified sequence located on chromosome 6 might be relevant in the pathogenesis of human NSCLC. Int. J. Cancer (Pred. Oncol.), 84:344-349, 1999.