Expression profile of 11 proteins and their prognostic significance in patients with chronic lymphocytic leukemia (CLL)

It has been suggested that the expansion of the leukemic cells in chronic lymphocytic leukemia (CLL) is due to dysregulation of pathways of programmed cell death (apoptosis) rather than cell proliferation, although differences may exist in early vs late and treated vs untreated patients. In the present study, we analyzed the expression of 11 proteins in CLL cells that are implicated in the control of apoptosis, proliferation, and differentiation, and correlated this expression profile with survival. Using a quantitative solid-phase radioimmunoassay (RIA), we measured the cellular protein levels of Bcl-2, cyclin D1, PCNA, ATM, Fas, Bax, retinoic acid receptor alpha (RARα), retinoic acid receptor beta (RXRβ), Flt1, VEGF, and cellular β2-microglobulin in 230 samples of CLL. Univariate analysis using the Cox proportional hazard model showed a correlation with survival of only the following proteins: Bcl-2 (P < 0.001), cyclin D1 (P = 0.027), Fas (P = 0.055), PCNA (P < 0.001), and ATM (P = 0.028). In a multivariate analysis using classification and regression tree analysis (CART), five groups of patients (nodes) could be generated with significant differences of survival expectation (P < 0.0001) based on levels of expression of the above proteins. Based on CART analysis, Bcl-2 levels emerge as the most important protein in predicting survival between all 11 proteins studied. Patients with marked elevation in Bcl-2 levels had the worst outcome while patients with intermediate levels, but with high levels of PCNA and cyclin D1 or abnormal ATM expression had intermediate survival. These data indicate that intracellular levels of proteins such as Bcl-2, ATM, cyclin D1, and PCNA can be used as markers to predict clinical behavior and survival in patients with CLL. The pathways in which these proteins are involved may also represent possible targets for future therapeutic trials in CLL.

[1]  E L Kaplan.  NON-PARAMETRIC ESTIMATION FROM INCOMPLETE OBSERVATION , 1958 .

[2]  D. O'Connor,et al.  Predictors of hysterectomy: an Australian study. , 1999, American journal of obstetrics and gynecology.

[3]  Daryl Pregibon,et al.  Tree-based models , 1992 .

[4]  John Calvin Reed,et al.  Drug-induced apoptosis in B-cell chronic lymphocytic leukemia: relationship between p53 gene mutation and bcl-2/bax proteins in drug resistance. , 1996, Oncogene.

[5]  K. Do,et al.  Combining non-parametric models with logistic regression: an application to motor vehicle injury data , 2000 .

[6]  P. Grambsch,et al.  Martingale-based residuals for survival models , 1990 .

[7]  H. Döhner,et al.  Somatic ATM mutations indicate a pathogenic role of ATM in B-cell chronic lymphocytic leukemia. , 1999, Blood.

[8]  M. LeBlanc,et al.  Relative risk trees for censored survival data. , 1992, Biometrics.

[9]  Robert Tibshirani,et al.  An Introduction to the Bootstrap , 1994 .

[10]  E. Estey,et al.  Angiogenesis in acute and chronic leukemias and myelodysplastic syndromes. , 2000, Blood.

[11]  D.,et al.  Regression Models and Life-Tables , 2022 .

[12]  K R Hess,et al.  Classification and regression tree analysis of 1000 consecutive patients with unknown primary carcinoma. , 1999, Clinical cancer research : an official journal of the American Association for Cancer Research.

[13]  D C Case,et al.  Clinical staging of chronic lymphocytic leukemia. , 1977, The Journal of the Maine Medical Association.

[14]  M. Mardiney,et al.  Alteration of cellular ribonucleases associated with murine oncogenic virus infection. , 1978, Biomedicine / [publiee pour l'A.A.I.C.I.G.].

[15]  R. Peto,et al.  Clinical trial methodology , 1978, Nature.

[16]  D. Johnston,et al.  Prognostic value of proliferating cell nuclear antigen expression in chronic lymphoid leukemia. , 1992, Blood.

[17]  K. Do,et al.  Morphology of sporadic colorectal cancer with DNA replication errors , 1998, Gut.

[18]  E. Montserrat,et al.  Chronic Lymphocytic Leukaemia: Proposals for a Revised Prognostic Staging System , 1981 .

[19]  T. McDonnell,et al.  Bcl-2 expression in chronic lymphocytic leukemia and its correlation with the induction of apoptosis and clinical outcome. , 1996, Leukemia.

[20]  L. Foroni,et al.  Expression and function of the FAS antigen in B chronic lymphocytic leukemia and hairy cell leukemia. , 1995, Leukemia.

[21]  T. Manshouri,et al.  Expression profile of MDM‐2 proteins in chronic lymphocytic leukemia and their clinical relevance , 1997, American journal of hematology.

[22]  Leo Breiman,et al.  Classification and Regression Trees , 1984 .

[23]  H. Kantarjian,et al.  Variations in the low levels of cyclin D1/BCL1 have prognostic value in chronic lymphocytic leukemia. , 2000, Leukemia research.

[24]  John Calvin Reed,et al.  bcl-2 Gene hypomethylation and high-level expression in B-cell chronic lymphocytic leukemia , 1993 .

[25]  L. Moretti,et al.  bcl-2 gene expression in hematopoietic cell differentiation. , 1992, Blood.

[26]  D. Colomer,et al.  Involvement of CED-3/ICE proteases in the apoptosis of B-chronic lymphocytic leukemia cells. , 1997, Blood.

[27]  C. Pepper,et al.  REGULATION OF CLINICAL CHEMORESISTANCE BY bcl‐2 AND BAX ONCOPROTEINS IN B‐CELL CHRONIC LYMPHOCYTIC LEUKAEMIA , 1996, British journal of haematology.

[28]  H. Kantarjian,et al.  Deficiency of the ATM protein expression defines an aggressive subgroup of B-cell chronic lymphocytic leukemia. , 1998, Cancer research.

[29]  H. Gralnick,et al.  Proposals for the classification of chronic (mature) B and T lymphoid leukaemias. French-American-British (FAB) Cooperative Group. , 1989, Journal of clinical pathology.

[30]  D. Johnston,et al.  Proliferating cell nuclear antigen (PCNA) expression in chronic lymphocytic leukemia (CLL). , 1993, Leukemia & lymphoma.

[31]  S. Chevret,et al.  Prognostic importance of serum soluble CD23 level in chronic lymphocytic leukemia. , 1996, Blood.

[32]  John Calvin Reed.  Molecular biology of chronic lymphocytic leukemia. , 1998, Seminars in oncology.

[33]  Ash A. Alizadeh,et al.  Distinct types of diffuse large B-cell lymphoma identified by gene expression profiling , 2000, Nature.

[34]  Christina Gloeckner,et al.  Modern Applied Statistics With S , 2003 .

[35]  M Schumacher,et al.  Comparison of the Cox model and the regression tree procedure in analysing a randomized clinical trial. , 1993, Statistics in medicine.

[36]  T. Manshouri,et al.  ATM gene deletion in patients with adult acute lymphoblastic leukemia , 2000, Cancer.

[37]  G M Cohen,et al.  Caspases: the executioners of apoptosis. , 1997, The Biochemical journal.

[38]  E. Read,et al.  Fas‐mediated lysis of chronic lymphocytic leukaemia cells: role of type I versus type II cytokines and autologous FasL‐expressing T cells , 1999, British journal of haematology.