Analysis of the biological properties and use of comparative genomic hybridization to locate chromosomal aberrations in the human testicular seminoma cell line JKT-1 and its highly metastatic cell line JKT-HM.

Abstract

To examine the biological properties, and utility of comparative genomic hybridization (CGH) to locate chromosomal aberrations, in a new human testicular seminoma cell line, JKT-1, and a highly metastatic cell line, JKT-HM, developed as an animal model of spontaneous metastasis. JKT-HM was isolated by transplanting cells of JKT-1 into the dorsal skin of nude mice, using methods developed previously. The biological properties of JKT-1 and JKT-HM cells were examined using assays of cell proliferation and in vitro tumour cell invasion, and the DNA index (by flow cytometry). CGH was used to analyse chromosomal aberrations and to detect chromosomal regions causing metastasis in the testicular seminoma cell lines. The JKT-1 and JKT-HM cells showed no difference in morphology or cell proliferation. After transplanting JKT-HM into mice, the cells metastasized to the lung and lymph nodes in all five mice by 50 days. The in vitro tumour cell invasion and animal assays suggested potential invasion and metastasis of JKT-HM. The DNA index was 1.48 for JKT-1 and 1.50 for JKT-HM. CGH analysis revealed various chromosomal aberrations undetected by examining their karyotypes, e.g. loss of 18p, Yq and gain of Xq, and the technique has potential to detect genetic aberrations related to metastasis in this model. The two cell lines JKT-1 and JKT-HM, and the metastatic animal model used, were useful in studying human testicular seminoma and the metastatic behaviour of cancer. In addition, CGH was useful for analysing the chromosomes of two different cell lines derived from the same parent line.