TCL1 oncogene expression in B cell subsets from lymphoid hyperplasia and distinct classes of B cell lymphoma.

Activation of the TCL1 oncogene has been implicated in T cell leukemias/lymphomas and recently was associated with AIDS diffuse large B cell lymphomas (AIDS-DLBCL). Also, in nonmalignant lymphoid tissues, antibody staining has shown that mantle zone B cells expressed abundant Tcl1 protein, whereas germinal center (GC; centrocytes and centroblasts) B cells showed markedly reduced expression. Here, we analyze isolated B cell subsets from hyperplastic tonsil to determine a more precise pattern of Tcl1 expression with development. We also examine multiple B cell lines and B lymphoma patient samples to determine whether different tumor classes retain or alter the developmental pattern of expression. We show that TCL1 expression is not affected by Epstein-Barr virus (EBV) infection and is high in naïve B cells, reduced in GC B cells, and absent in memory B cells and plasma cells. Human herpesvirus-8 infected primary effusion lymphomas (PEL) and multiple myelomas are uniformly TCL1 negative, whereas all other transformed B cell lines tested express moderate to abundant TCL1. This observation supports the hypothesis that PEL, like myeloma, usually arise from post-GC stages of B cell development. Tcl1 protein is also detected in most naïve/GC-derived B lymphoma patient samples (23 of 27 [85%] positive), whereas most post-GC-derived B lymphomas lack expression (10 of 41 [24%] positive). These data indicate that the pattern of Tcl1 expression is distinct between naïve/GC and post-GC-derived B lymphomas (P < 0.001) and that the developmental pattern of expression is largely retained. However, post-GC-derived AIDS-DLBCL express TCL1 at a frequency equivalent to naïve/GC-derived B lymphomas in immune-competent individuals (7 of 9 [78%] positive), suggesting that TCL1 down-regulation is adversely affected by severe immune system dysfunction. These findings demonstrate that TCL1 expression in B cell lymphoma usually reflects the stage of B cell development from which they derive, except in AIDS-related lymphomas.

Preoperative prostate needle biopsy p27 correlates with subsequent radical prostatectomy p27, Gleason grade and pathological stage.

PURPOSE: Loss of p27 protein expression in radical prostatectomy specimens has been shown to be an adverse prognostic factor in patients with clinically localized prostate cancer. To our knowledge no studies have examined p27 expression in prostate needle biopsies. To test the potential predictive power of p27 in prostate biopsies we compared p27 expression in preoperative biopsies and matched prostatectomy specimens of patients with clinically localized prostate cancer. MATERIALS AND METHODS: Matched biopsies and radical prostatectomy specimens from 44 patients were examined. Mean followup was 22.7 months (range 1 to 46). Tumors expressing less than 30% positive nuclei were classified as low expressors and tumors expressing greater than 30% positive nuclei were classified as high expressors of p27 protein. RESULTS: Expression of p27 in prostate biopsies correlated significantly with subsequent p27 expression in radical prostatectomy specimens (p = 0.002). Sensitivity and specificity of biopsy p27 for predicting subsequent prostatectomy p27 were 87.5% and 88.9%, respectively (p <0.001). Univariate analysis showed that low expression of p27 in the biopsy correlated significantly with biopsy and prostatectomy Gleason score (p = 0.000 and 0.001, respectively), and final pathological stage (p = 0.028). Despite the small sample size and short followup, 36.4% of patients with low p27 expression had a biochemical recurrence compared to only 12.1% with high expression (hazards ratio 3.56). In addition, Kaplan-Meier analysis suggested that low p27 expression in prostate biopsies may be associated with a shorter time to recurrence, although this did not reach statistical significance (p = 0.081). CONCLUSIONS: Expression of p27 in prostate biopsies can be used to predict the degree of expression in radical prostatectomy specimens. As loss of p27 protein expression in prostatectomy specimens has been shown to correlate with biochemical recurrence and shortened prostate specific survival, these results suggest that biopsy p27 may help identify high risk patients preoperatively.