Objective: To investigate the proteins expression difference after upregulation of human CD99 in Hodgkin Lymphoma cell line, L428 cell, and verify the function of differential proteins. Methods: The differential proteins were detected by two-dimensional fluorescence difference gel electrophoresis and mass spectrometry analysis, cluster analysis was done by GOfact. Results: There were 38 proteins screened out, of which 21 proteins were positively associated with CD99, while 17 proteins were negative. Among the 38 proteins, 32 proteins participated in biological process, and 35 proteins were involved in the composition and construction. And 28 proteins participated in multifaceted biological activities including antioxidation, protein binding, catalytic activity, regulation of enzyme, signal transduction, molecular structure, regulation of translation and ion transport. Conclusions The changes of the differential proteins, correlated with cytoskeleton, cell differentiation, signal pathway and regulating gene expression, are closely relevant to the translation between Hodgkin/Reed-Sternberg and B lymphocyte cell.

Objective: To explore the role of GTP binding protein 2 (Septin2) in the differentiation of Hodgkin’s Lymphoma H/RS cells (Hodgkin/Reed-Sternberg) to B lymphocytes. Methods: The expressions of Septin2 mRNA and protein in Hodgkin’s Lymphoma cell line L428 which CD99 was overexpressed were detected by RT-qPCR and Western blot,confocal laser microscopy and immunocytochemistry (ICC) . RT-qPCR and Western blot were used to assay the expression of Septin2 after Septin2-siRNA transfected into L428 cells, and confocal laser microscopy, CCK8 assay and flow cytometry were used to analyze the changes of F-actin cytoskeleton,cell proliferation ability and immunophenotype. Results: The low expressions of Septin2 mRNA and protein were detected in L428 cell line after overexpresion of CD99 (0.329±0.019 vs 1.000, P=0.001) and Septin2 siRNA transfection (0.276±0.025 vs 1.000, P=0.000) compared to controls. Compared to vector group, Septin2 siRNA transfection could lead to decrease of cell size, decline of proliferation activity (F=204.927, P<0.001) and reconstruction of F-actin cytoskeleton, and the expression of specific antigen markers CD30 and CD15 of H/RS cell decreased, B cell antigen marker CD19 as well as germinal center marker CD10 and early plasma cell marker CD38 were up-regulated. Conclusion Septin2 interference promotes H/RS cells’ redifferentiation to B lymphocytes