Bcl-10 protein highly correlates with the expression of phosphorylated p65 NF-kappaB in peripheral T-cell lymphomas and is associated with clinical outcome.

AIMS: In T cells, protein kinase C (PKC) theta plays a major role in T-cell receptor (TCR)-mediated activation of a novel nuclear factor (NF)-kappaB pathway that involves phosphorylation of p65 at serine 536 (Pp65(Ser536)). Bcl-10 acts along the same pathway downstream of PKC theta to activate NF-kappaB. The aim was to investigate the relationship between the expression of PKC theta, Bcl-10 and P-p65(Ser536) proteins and their prognostic significance in peripheral T-cell lymphomas (PTCLs). METHODS AND RESULTS: Paraffin-embedded tissues from 30 patients with PTCLs treated with curative intention were evaluated retrospectively. Expression of PKC theta, Bcl-10 and P-p65(Ser536) proteins was assessed using immunohistochemistry. Expression of PKC theta was detected in 22 of 30 cases (73%), Bcl-10 in 20 of 30 (67%) and P-p65(Ser536) in 21 of 30 (70%). Bcl-10+ tumours were associated with PKC theta (18 of 22) (P < 0.0001) and Pp65Ser536 (19 of 21) expression (P < 0.0001). Patients with Bcl-10+ or P-p65(Ser536+) tumours fared better, with a 5-year overall survival of 48 and 45%, respectively, versus 0% for negative tumours (P = 0.029 and P = 0.04, respectively). CONCLUSIONS: Bcl-10 is expressed in PTCLs, correlates with PKC theta and Pp65(Ser536) expression and seems to be associated with better survival.