An inverse correlation between p27 Kip1 expression and proliferation has been recently established in tissues derived from human lymphomas. The nucleophosminanaplastic lymphoma kinase (NPM ± ALK)/phospholipase C-g (PLCg) complex also appears to play an important role in cell proliferation and malignant transformation of anaplastic large cell lymphoma (ALCL). In this study, we report that SUDHL-1 and KARPAS 299 ALCL-derived cell lines present di erent sensitivity to the antiproliferative e ect of recombinant adenovirus-mediated p27 Kip1 expression or to serumstarvation in culture media. The results indicate that exogenous p27 Kip1 may interact with the NPM ± ALK/ PLCg pathway in SUDHL-1 but not in KARPAS 299 cells. This interaction correlates with changes in cell cycle and cell morphology observed mainly in SUDHL-1 cells. The percentage of SUDHL-1 cells in S phase declines, whereas it is almost unchanged in KARPAS 299 cells as compared to the controls after 96 h of infection with the recombinant adenovirus. Furthermore KARPAS 299 cells are resistant to serum-starvation due to de®cient p27 Kip1 -upregulation and G1 arrest, whereas SUDHL-1 cells respond with increased G1 phase and p27 Kip1 -upregulation after 48 h of serum-starvation. Both cell lines express appropriate variation of levels of cyclins E and A, and Rb-phosphorylation as expected by growing them in culture media with di erent FBS content. Although both cell lines express cyclin D2, SUDHL-1 cells only present high level of cyclin D3. Moreover SUDHL-1 cells express high level of PTEN and the PKB/Akt pathway is constitutively activated in both cell lines. Lastly SUDHL-1 cells show higher levels of phosphotyrosine-containing proteins that is correlated with a higher NPM ± ALK-associated autophosphorylation activity compared to KARPAS 299 cells. Our study clearly identi®es some of the biochemical di erences that may explain the di erence in sensitivity to antiproliferative stimuli shown by two cell lines derived from the same type of lymphoma. Oncogene (2001) 20, 4466 ± 4475.

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) p27Kip1 (Adp27), p21Waf1 (Adp21) and p16INK4A (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 p27Kip1, p21Waf1 and p16INK4A 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 p27Kip1, p21Waf1 and p16INK4A may be further explored as a tool for gene therapy of t(2;5)-derived ALCL.

Recombinant adenoviruses expressing wild-type p53 (AdWTp53) and p27 Kip1