TRAF6 Induces the Activation of the PI3K/NF-κB Signaling Pathway in Non-Hodgkin’s Lymphoma

Abstract

Background: Lymphoma has emerged as the most common neoplasm among children, nearly half of them being non-Hodgkin lymphoma (NHL). To explore appropriate therapeutic targets and suggest directions for future research, this study aimed to identify the effects of TNF receptor-associated factor 6 (TRAF6) on NHL and its correlation with the phosphatidylinositol 3-kinase and nuclear factor kappa-B (PI3K/NF-κB) pathway. Methods: Blood samples were collected from healthy children and those affected with NHL. The cell lines, Raji human B lymphoma (iCell-h178) and U-937 human leukemia (iCell-h267), were maintained on RPMI-1640 culture medium. The expression profile of TRAF6, phosphatidylinositol 3-kinase (PI3K), and nuclear factor kappa-B (NF-κB) was determined by performing the real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) using blood samples from both healthy and affected children. Furthermore, RT-qPCR, Western Blot, Cell Counting Kit-8 (CCK-8) assay, and flow cytometry were used to evaluate the impact of TRAF6 expression levels on NHL cell proliferation and apoptosis, as well as the role of TRAF6 in mediating the PI3K/NF-κB pathway. Results: TRAF6, PI3K, and NF-κB were over-expressed in NHL patients (p < 0.05). Decreased/increased TRAF6 expression led to decreased/increased Proliferating cell nuclear antigen (PCNA), Cyclin D1, Bcl-2 protein expression and NHL cell proliferation (p < 0.05), while increasing/decreasing Cleaved Caspase-3, Bax protein expressions and NHL cell apoptosis (p < 0.05). In addition, decreased/increased TRAF6 expression could lead to decreased/increased p-PI3K, p-NF-κB protein expressions (p < 0.05). Conclusion: In summary, TRAF6 was over-expressed in NHL patients and NHL cell lines. However, down-regulation of TRAF6 reduced proliferation and induced apoptosis in NHL cells through deactivating PI3K/NF-κB pathway, thus suppressing the progression of NHL.