Clonal derivatives of a herpes type 2 transformed hamster cell line (333‐8‐9): Cytogenetic analysis, tumorigenicity and virus sequence detection

Abstract

The characteristics of the Syrian hamster cell line (333‐8‐9), putatively transformed by herpes virus type 2 (HSV‐2), strain 333, have been examined. The line has been cloned and the clones characterized cytogenetically and morphologically. The original line and the clones have been assayed for tumorigenicity and for the presence of herpes‐virus‐specific nucleic acid sequences using in situ hybridization with ¹²⁵I HSV‐2 DNA. The line 333‐8‐9 is hyperdiploid with a mode of 49 chromosomes and contains a spectrum of cytogenetic marker chromosomes present in varying frequencies. The clones demonstrate a segregation of these marker chromosomes and other abnormal chromosomes. Cloned lines have distinct stem‐cell types with the characteristic abnormal chromosomes present in a high percentage of cells. Some of the marker chromosomes have been identified by Giemsa banding techniques. All the clones have distinctive, persistent in vitro morphologies, ranging from purely epithelial to purely fibroblastic. They differ from the line 333‐8‐9 and between themselves in tumorigenicity, varying from highly tumorigenic to entirely nontumorigenic. Herpes virus 2 specific sequences have been detected in the original cell line and in all but two of the clones. There does not appear to be any obvious correlation between the three parameters of: (1) detection of HSV‐2 information; (2) marker chromosome occurrence; and (3) tumorigenicity.