[Expression of myocyte enhancer factor 2B in mantle cell lymphoma and its clinical significance]

Objective: To investigate the expression of myocyte enhancer factor 2B (MEF2B) in mantle cell lymphomas (MCL), and to analyze the correlation between the expression of MEF2B and pathological subtypes, structural subtypes, SOX11 expression and its clinical significance. Methods: Paraffin-embedded tissues were stained with HE, immunohistochemistry (EnVision method) and fluorescence in situ hybridization (FISH) , in addition, the clinical and pathological data of 60 cases of MCL were collected at Sun Yat-sen University Foshan Hospital and Sun Yat-sen University Cancer Center from January,2002 to May, 2019 for analysis. Results: Of the 60 MCLs, males is predominant (M∶F=3∶1). Histologically, the typical MCL is the majority (classical MCL: variant type MCL=48 cases:12 cases) . Fifty cases were classified into non-complete FDC meshwork type MCL, and the remaining 10 cases were classified into the complete-FDC meshwork type MCL group. Patients with classical MCL were more than 60 years old. The coexistent lesion sites both node and extranode in pathological subtype or structural subtype was the most common lesion sites. SOX11(+) MCL was common in classical MCL (P=0.040) and tended to be complete-FDC meshwork type MCL (P=0.086). The expression rate of MEF2B in MCL was 60.0%(36/60). This rate of MEF2B in classical type, complete-FDC meshwork type and SOX11(+) MCL was significantly higher than that variant type, no complete-FDC meshwork type, SOX11(-)MCL (P<0.05), respectively. There was no difference in clinical characteristics of MCL between MEF2B positive and negative groups. Compared with SOX11(-)MCL, the percentage of MEF2B expressed in tumor cells of SOX11(+)MCL was significantly higher (P=0.027). The expression of MEF2B was not related to the proliferation of tumor cells (P=0.341). There was no significant difference in the survival rate between different expression groups of MEF2B and SOX11 (P=0.304 and P=0.819, respectively). Only the mortality of variant type (blastoid/pleomorphic) MCL within 2 years was significantly higher than that of classical type MCL (P<0.05). Conclusions: The expression of MEF2B in MCL is related to the pathological subtypes, structural subtypes and the expression of SOX11, but not to the proliferation and prognosis. The high mortality rate within 2 years is only found in variant MCL. However, the role of MEF2B in MCL needs to be further studied.