Effects of adenovirus-mediated expression of p27^Kip1, p21^Waf1 and p16^INK4A in cell lines derived from t(2;5) anaplastic large cell lymphoma and Hodgkin's disease

We investigated the response of SUDHL-1 and L428 cells, derived from t(2;5)-anaplastic large cell lymphoma (ALCL) and Hodgkin's disease (HD), respectively, to recombinant adenoviruses expressing cyclin-dependent kinase inhibitors (CDKIs) p27^Kip1 (Adp27), p21^Waf1 (Adp21) and p16^INK4A (Adp16). Cell cycle analysis of SUDHL-1 cells after 24 h of infection with 200 multiplicity of infection (MOI) of Adp27, Adp21, and Adp16, showed very high levels of cell debris in the subG1 area. The magnitude of cell debris-events was Adp27/Adp21 > Adp16. Cell cycle analysis of L428 cells revealed absence of cell debris and increased G2 phase in all the groups of cells tested as compared to the controls (mock and AdNull). A minimal increase in G1 phase was also evident in cells infected with Adp27 (52%) compared to uninfected cells (43%), AdNull (45%) and to cells infected with Adp21 (37%) and Adp16 (31%). The presence of significant levels of Coxsackie-adenovirus receptor (CAR) on the cell surface of L428 cells excluded the cell membrane-barrier as responsible for the differences in cell observed in response to the recombinant adenovirus-mediated CDKIs expression as compared to SUDHL-1. We also showed that the recombinant adenovirus-mediated cytotoxicity measured as apoptosis was MOI-and vector-dependent in SUDHL-1 cells at lower MOI (100). In conclusion, the therapeutic effect induced by recombinant adenoviruses expressing p27^Kip1, p21^Waf1 and p16^INK4A is cell-dependent in cells derived from selected lymphoid malignancies. Biochemical cellular differences more than cell surface barriers seem to be responsible for differences in response to recombinant adenovirus-mediated expression of cytotoxic genes. Moreover, the cytotoxicity of recombinant adenoviruses expressing p27^Kip1, p21^Waf1 and p16^INK4A may be further explored as a tool for gene therapy of t(2;5)-derived ALCL.