Study On The Expression And Prognosis Correlation Of CARD11 And NF-κB In Primary Gastrointestinal Diffuse Large B Cell Lymphoma

Background:Diffuse large B-cell lymphoma(DLBCL) represents the most common type of aggressive lymphoma. DLBCL is heterogeneous with respect to morphology, immunophenotype, biology, clinical presentation and outcome. The common clinical manifestation of DLBCL is rapidly enlarging lymph nodes, and it can also be primary in any extranodal tissues and organs of which the most common site is extranodal gastrointestinal.Currently, the primary gastrointestinal diffuse large B cell lymphoma (PGI-DLBCL) data is very limited. The degree of malignancy and invasiveness is higher than nodal DLBCL in clinic, and it was difficult to distinguish from the gastrointestinal common disease and gastrointestinal cancer.Therefore, when found, PGI-DLBCL is at clinical later stage and hence misdiagnosis rate is higher. Because operation have many fatal complications, the chemotherapy treatment as the preferred choice of gastrointestinal DLBCL, but some patients are not sensitive to conventional chemotherapy and have poor prognosis. Further elucidating the pathogenesis of DLBCL and searching for potential therapeutic targets remain a priority to improve the poor prognosis.Constitutive activity of the NF-κB pathway may contribute to the poor prognosis of patients with activated B cell–like (ABC) subgroup of DLBCLs, CARD11 is the important upstream signal protein in the signaling pathway of NF-κB. Furthermore, various pre-clinical data have proved the importance of CARD11 in DLBCL. Now there are few reports about the prognosis relationships among CARD11, NF-κB signaling transduction pathway and the immunophenotyping, the clinical features and biological characteristics of PGI-DLBCL.Objective:We detected the expression of CARD11, NF-κB subtypes p65, p50, CD10, Bcl-6, Mum-1, Bcl-2 and Ki-67 in primary gastrointestinal diffuse large B-cell lymphoma and associated with clinical and follow-up data. Our aim was to study and research systematically the relationships between CARD11 and NF-κB subtypes p65, p50 with the PGI-DLBCL immunophenotyping, the clinical features, biological behaviors of PGI-DLBCL. We also probed into screen the prognostic factors of PGI-DLBCL to find a more reliable molecular markers of prognosis. we can better provide a new theoretical basis for clinical application of targeted chemotherapy drugs of DLBCL.Methods:A total of 54 cases of PGI-DLBCL underwent operation in Shanghai Changzheng Hospital from May 1998 to June 2010 with complete clinical and follow up data involved in this study. The expression of CD10, Bcl-6, Mum-1 to immunophenotype and CARD11, NF-κB subtypes p65, p50 were detected on the formalin-fixed paraffin-imbedding tissues by immunohistochemistry. The SPSS statistical software were used in analyses on relationship between each factor expression and biological behavior, the apoptotic index Bcl-2 and the proliferation index Ki-67 of PGI-DLBCL. The significance of gene expression and survival period was determined by Kaplan Meier survival analyses and Log-Rank test, meanwhile the prognostic factors should be screened. Cox model were estabished according to multivariate analyses of survival data.Results: The positive expression rate of were detected as 28% in CD10, 69% in Bcl-6, 81% in Mum-1, 70% in CARD11, 72% in NF-κB/p65, 65% in NF-κB/p50 respectively. Of 54 primary gastrointestinal diffuse large B-cell lymphoma, 19 cases were classified as germinal center B-cell-like group(GCB), and 35cases asctivated B-cell like group(ABC). The expression rates of CARD11, NF-κB/p65 and NF-κB/p50 were 26.3%, 25.6% and 25.7% in GCB DLBCL, but were 73.7%, 74.4%and 74.3% in ABC DLBCL. The expressions rates of CARD11, NF-κB/p65 and NF-κB/p50 were higher in ABC-DLBCL than in GCB-DLBCL(P<0.05). Significant correlation was found between low positive expression and high positive expression of NF-κB/p65 and NF-κB/p50, with regard to CARD11(r=0.314, r=0.322, P<0.05). CARD11 expressed higher in the group of high-positive expression of NF-κB/p65 and NF-κB/p50. No significance correlation were found between the positive expression of CARD11 and gender, age, onset sites, clinical stage, depth of invasion, lymph node involvement, extranodal involvement sites, tumor size, LDH, ECOG, IPI, B symptoms of patients(P>0.05).The expression of NF-κB/p65 in PGI-DLBCL tissues was correlated with of extranodal involvement sites(group"≥2"> group"0~1") (P<0.05), but was not correlated with gender, age, onset sites, clinical stage, depth of invasion, lymph node involvement, tumor size, LDH, ECOG, IPI, B symptoms of patients(P>0.05). The expression of NF-κB/p50 in PGI-DLBCL tissues was correlated with of clinical stage(group"Ⅲ/Ⅳ"> group"Ⅰ/Ⅱ") (P<0.05), extranodal involvement sites(group"≥2"> group"0~1") (P<0.05), LDH(group"higher"> group"normal") (P<0.05), IPI(group"low risk"< group"low/intermediate"= group"high/intermediate"< group"high risk") (P<0.05), but was not correlated with gender, age, onset sites, depth of invasion, lymph node involvement, tumor size, ECOG, B symptoms of patients(P>0.05). No significant correlation were found in Bcl-2 and Ki-67 of CARD11. Significant correlation was found between low positive expression and high positive expression of NF-κB/p65 and NF-κB/p50, with regard to Bcl-2(r=0.350, r=0.328, P<0.05). Significant correlation was found between low positive expression and high positive expression of NF-κB/p65 and Ki-67(r=0.271, P<0.05). No significance correlation were found in NF-κB/p50 and Ki-67(P>0.05). The gender, extranodal involvement sites, LDH, IPI, the immunophenotyping, expression of NF-κB/p65 were all correlated with survival time. The male group lived shorter than the female group; With the extranodal involvement sites, the"≥2"group lived shorter than the"0~1"group; the serum level of LDH at diagnosis had significantly lower survival rate; With the risk factors increasing, survival time of the lower levels("low risk"and"low/intermediate")were longer than the higher level("high risk"and"high/intermediate"). Mean survival time of ABC is lower than GCB, NF-κB/p65 positive expression was longer than its negative expression.The other clinical agents were not correlated with survival time in PGI-DLBCL(P>0.05). The extranodal involvement sites and expression of NF-κB/p65 entered the final Cox model for prognosis of PGI-DLBCL.Conclusion:The expressions rates of CARD11, NF-κB/p65 and NF-κB/p50 were higher in ABC-DLBCL than in GCB-DLBCL, and the expression of CARD11 was statistically related with NF-κB/p65 and NF-κB/p50, which means CARD11 was consistend with NF-κB in ABC-DLBCL, and CARD11 as the important signal protein in the signaling pathway of NF-κB played a certain role in development of PGI-DLBCL. It means that, in clinical therapies, CARD11 could be a new potential target for treating PGI-DLBCL. The expression of NF-κB/p65 in PGI-DLBCL tissues was correlated with of extranodal involvement sites and the expression of NF-κB/p50 in PGI-DLBCL tissues was correlated with of clinical stage, extranodal involvement sites, LDH and IPI. Significant positive correlation were found in Bcl-2 of NF-κB/p65 and NF-κB/p50, so NF-κB could inhibit cell apoptosis and have positive correlation with the development and invasivion of PGI-DLBCL. Combining with the immunophenotyping, NF-κB could predict the development of PGI-DLBCL. The extranodal involvement sites, LDH, IPI, the immunophenotyping, expression of NF-κB/p65 could be the prognostic agents of PGI-DLBCL. The extranodal involvement sites and expression of NF-κB/p65 are major factors on prognosis of patients with PGI-DLBCL, and a high PI correlates with high risk and short survival time.