Evidence of Somatic Pairing in an Adenocarcinoma of the Lung.

Abstract

SummaryChromosomal analysis of an adenocarcinoma of the lung showed three clones. Additionally three cells were also recorded which showed mitotic chromosomal pairing involving varying number of chromosomes. In one of these cells almost the entire genome was involved in mitotic pairing of chromosomes. The importance of somatic pairing of chromosomes in the context of tumor evolution is highlighted.During the last decade, lung cancer (CA) has become the leading cause of deaths by cancer in both men and women. In the United States, lung cancer has an annual incidence of some 180,000cases with approximately 150,000 deaths. Unlike hematologic neoplasms where chromosomal aberrations correlate with diagnosis, management and prognosis, similar information regarding solid tumors is not yet recognized.We have made the observation in a case of adenocarcinoma of the lung which showed three different clones and also mitotic pairing of GTG banded homologous chromosomes.We have highlighted the significance of mitotic pairing of chromosomes in tumor evolution. Material and methodAfter excision, the tumor diagnosed as adenocarcinoma of the lung was brought in RPMI-1640 immediately to the laboratory. It was minced and exposed to 16 mg of collagenase in 10 ml . In addition to these clones, three cells in close proximity to each othcr showing somatic pairing among homologous chromosomes were observed on one of the slides. Chiasmata were absent in each of the chromosomal pairs. The cell with the maximum number of pairs showed chromosomal association of almost the entire genome (Fig. 1).