[Significance of phosphorylation of mitogen-activated protein kinase and signal transducer and activator of transcription 3 and cyclin D1 protein expression in Hodgkin's lymphomas].

Background & Objective: Signal cascades of mitogen-actived protein kinase(MAPK) and signal transducer and activator of transcription 3 (Stat3) are two main signal transduction pathways which were associated with cell proliferation and malignant transformation.MAPK and Stat3 proteins are activated by phosphorylation. The biological effects which are caused by multiple cytokines produced by Hodgkin's lymphoma(HL) cells are mediated through MAPK and Stat3 signal pathways. This study was designed to investigate significance of MAPK and Stat3 phosphorylation(p-MAPK and p-Stat3) and cyclin D1 protein expression in HL.

Methods: SP immunohistochemistry was used to detect expression of p-MAPK, p-Stat3, and cyclin D1 protein in 45 cases of HL of various types.

Results: The expression positive rates of p-MAPK, p-Stat3, and cyclin D1 proteins were 73.3%(33/45),64.4%(29/45), and 68.9%(31/45), respectively. The positive expression levels of p-MAPK and cyclin D1 protein gradually increased(P< 0.05), whereas that of p-stat3 had no significant difference(P >0.05) in four subsets(LR:lymphocyte-rich classical type; NS:nodular sclerosis type; MC:mixed cellularity type; LD:lymphocyte depletion type) of all cases. The expression of p-MAPK was positively related to that of cyclin D1 protein (r(s)=0.7254,P< 0.01), but the expression of p-Stat3 was not related to that of cyclin D1 protein (r(s)=0.2197,P >0.05).

Conclusion: The data suggest that activation of MAPK may play an important role in genesis and progression of HL, but Stat3 activation is not associated with the progression of HL. MAPK may induce overexpression of cyclin D1 protein and results in persistent proliferation of RS/H cells in genesis and development of HL.