Overexpression of IL-9 receptor in diffuse large B-cell lymphoma.

Interleukin-9 (IL-9) is initially described as a growth factor secreted by helper T cells. It acts on a variety of immune cells via its receptor (IL-9R). Recently, the oncogenic activities of IL-9 and IL-9R were reported in some lymphomas but not diffuse large B-cell lymphoma (DLBCL). The purpose of the present study is to investigate the expression of IL-9R in pathological tissues from patients with DLBCL and to evaluate its correlation with clinical characteristics. Tissue samples from patients with DLBCL and reactive lymphoid hyperplasia were analyzed using RT-PCR, western blot and immunohistochemical staining. There was a higher expression of IL-9R within DLBCL tissues compared with hyperplasic lymph nodes. Immunohistochemical analysis indicated membrane localization of IL-9R in 22 of 36 (61.1%) DLBCL cases. The upregulated IL-9R was correlated to the serum levels of β2 microglobulin and albumin, International Prognostic Index (IPI) score as well as Ki-67 expression within tumor tissues. Our findings suggest that overexpression of IL-9R may contribute to the pathogenesis of DLBCL and is associated with some adverse prognostic parameters.