Defining the genetic characteristics of human hepatic stellate cell line LX-2 by spectral karyotyping and short tandem repeat genotyping

Objective: The hepatic cell line LX-2 was originally described in 2005 as a novel tool to study mechanisms of hepatic fibrogenesis and the testing of antifibrotic compounds [1]. It was established by immortalisation with the Simian Vacuolating Virus 40 (SV40) transforming (T) antigen and subsequent propagation in low serum conditions. Although this immortalized line is used in an increasing number of studies [2], a detailed genotypic characterisation that is mandatory for immortalized cell lines is still lacking. Design: In this study we attempt to describe the genetic characteristics and expression attributes of LX-2 cells to establish a reliable platform for explaining its cellular behaviour. Results: We established a single-locus short tandem repeat (STR) signature for the cell line and characterized the LX-2 karyotype by several cytogenetic and molecular cytogenetic techniques. Spectral karyotyping (SKY) revealed that LX-2 have marked heterogeneity with some chromosomal aberrations. However, despite some complexity and genetic variability, a few recurrent translocations have been identified that are specific for LX-2 and therefore suitable for proper identity testing. In addition, we found that this LX-2 cells express collagen type IV, collagen type I, fibronectin, vimentin, desmin, α-smooth muscle actin, connective tissue growth factor (CTGF), Id2, p21 and the complete set of TGF-β receptors including TβRI, TβRII and the accessory receptor endoglin (CD105) supporting the notion that this cell line originated from hepatic stellate cells. Conclusions: Our study provides criteria for cellular authentication of LX-2, and offers functional clues underlying its phenotypic and genotypic features. The provided information will increase the attraction for LX-2 cells in liver research and allow easy cellular authentication to avoid potential false experimental outcomes and scientific misinterpretation in studies in which LX-2 are employed.