[Cytogenetic studies on one human small cell lung cancer (SCLC) cell line, LTEP-sm].

Cytogenetic studies on LTEP-sm, the first SCLC cell line established in China, were carried out with G-banding techniques. Two 30-metaphase groups showing good G-banding patterns in generation 55 and 99 respectively were subjected to karyological analysis. The results are as follows: the modal number of chromosomes is 51-53 (generation 55) and 51-54 (generation 99). The cell line is hypotriploid. Six marker chromosomes were found. The frequency of interstitial deletion of the short arm of chromosome 3 (del 3p14-23) was as high as 26 (generation 55) and 28 (generation 99) in the two 30-metaphase groups analyzed. This result is in accordance with reports on the genetic markers of SCLC and SCLC variants published abroad. Another 5 marker chromosomes are: t(1;15) (1qter----1p22::15p12----15qter); del(1) (qter----p31:); del (7)(pter----q31:); t(6;9)(6pter----6q14:: 9q21----9qter); and del (12)(qter----p12.3). The incidence of the marker chromosomes was also calculated.