Differential growth of N- and S-type human neuroblastoma cells xenografted into SCID mice. Correlation with apoptosis

This study concerns tire role of apoptosis in the growth of human neuroblastomas transplanted into immunodeficient SCID mice. Human neuroblastoma cell lines may consist of one or more distinct phenotypes including the neural 'N-type' and flat substrate-adherent 'S-type'. A differential phenotype-specific proliferation was apparent among S- and N-type cell clones transplanted into SCTD mice when compared with the mild-type SK-N-BE(2) cell line. This differential growth capacity of the tumours was correlated with spontaneous apoptosis. Another SK-N-BE(2)-derived cell line (TGA), displaying high levels of apoptosis upon stable transfection with the full length 'tissue' transglutaminase (tTG) cDNA, was unable to indnce tumour development when xenografted into SCID mice. To support these observations, the expression of apoptosis-related genes (i.e., bcl-2, p53, and tTG) in the various neuroblastomas was also investigated.