International Journal of Cancer, 10 March 2003, Vol.104(1), pp.36-43
Cytotoxic drug treatment of neuroblastoma often leads to the development of drug resistance and may be associated with increased malignancy. To study the effects of long‐term cytotoxic treatment on malignant properties of tumor cells, we established 2 neuroblastoma cell sublines resistant to vincristine (VCR) and doxorubicin (DOX). Both established cell lines (UKF‐NB‐2VCR and UKF‐NB‐2DOX) were highly resistant to VCR, DOX and vice‐versa but retained their sensitivity to cisplatin. UKF‐NB‐2VCR and UKF‐NB‐2DOX expressed significant amounts of P‐glycoprotein, while parental cells were P‐glycoprotein negative. GD2 expression was upregulated, whereas NCAM expression was decreased in both resistant cells. Spectral karyotype (SKY) analysis revealed complex aberrant karyotypes in all cell lines and additional acquired karyotype changes in both resistant cells. All cell lines harbored high levels of N‐myc amplification. Compared to parental cells, UKF‐NB‐2VCR and UKF‐NB‐2DOX exhibited more than 2‐fold increase in clonal growth , accelerated adhesion and transendothelial penetration and higher tumorigenicity . We conclude that development of drug resistance and acquisition of certain karyotypic alterations is associated with an increase of additional malignant properties that may contribute to the poor prognosis in advanced forms of NB. The 2 novel neuroblastoma cell sublines also provide useful models for the study of drug resistance in aggressive forms of neuroblastoma. © 2002 Wiley‐Liss, Inc.
Neuroblastoma ; Drug Resistance ; Mdr‐1 ; Ncam ; Gd2 ; Karyotype