TAK1-binding proteins (TAB)2 and TAB3 are redundantly required for TLR-induced cytokine production in macrophages2024 · Transforming growth factor-β-activated kinase 1 (TAK1) plays a pivotal role in innate and adaptive immunity. TAK1 is essential for the activation of mitogen-activated protein kinases (MAPKs) and nuclear factor (NF)-κB pathways downstream of diverse immune receptors, including Toll-like receptors (TLRs). Upon stimulation with TLR ligands, TAK1 is activated via recruitment to lysine 63-linked polyubiquitin chain through TAK1-binding proteins (TAB) 2 and TAB3. However, the physiological importance of TAB2 and TAB3 in macrophages is still controversial. A previous study has shown that mouse bone marrow-derived macrophages (BMDMs) isolated from mice double deficient for TAB2 and TAB3 produced tumor necrosis factor (TNF)-α and interleukin (IL)-6 to the similar levels as control wild-type BMDMs in response to TLR ligands such as lipopolysaccharide (LPS) or Pam3CSK4, indicating that TAB2 and TAB3 are dispensable for TLR signaling. In this study, we revisited the role of TAB2 and TAB3 using an improved mouse model. We observed a significant impairment in the production of pro-inflammatory cytokines and chemokine in LPS- or Pam3CSK4-treated BMDMs deficient for both TAB2 and TAB3. Double deficiency of TAB2 and TAB3 resulted in the decreased activation of NF-κB and MAPK pathways as well as the slight decrease in TAK1 activation in response to LPS or Pam3CSK4. Notably, the TLR-mediated expression of inhibitor of NF-κB (IκB)ζ was severely compromised at the protein and mRNA levels in the TAB2/TAB3 double-deficient BMDMs, thereby impeding IL-6 production. Our results suggest that TAB2 and TAB3 play a redundant and indispensable role in TLR signaling pathway.
miR-935 Inhibits Oral Squamous Cell Carcinoma and Targets Inositol Polyphosphate-4-phosphatase Type IA (INPP4A).2020 · BACKGROUND/AIM: Oral squamous cell carcinoma (OSCC) is a common malignancy with poor prognosis. Therefore, novel therapeutic options are needed to improve prognosis of OSCC. Recently, microRNAs (miRs) have received increasing attention as a potential therapeutic tool for carcinomas. However, no definitive miR-based drugs for patients with OSCC have been reported to date. The aim of this study was to identify new miRs potentially involved in cellular processes associated with OSCC malignancy, which could lead to novel therapeutic strategies. MATERIALS AND METHODS: We identified miRs that are modulated in OSCC and possibly regulate OSCC malignancy, using miR microarray on OSCC cell lines. RESULTS: miR-935 and miR-509-3p were down-regulated in OSCC cell lines and patient tissues. When miR-935 was overexpressed in HSC-3-M3 cells, proliferation, migration, and invasion of the cell line was suppressed, whereas apoptosis was increased. Moreover, we showed that the gene inositol polyphosphate-4-phosphatase type I A (INPP4A) is a potential target whose expression is positively regulated by miR-935. CONCLUSION: miR-935 may function as a tumor suppressor by inhibiting OSCC malignancy via INPP4A induction. Therefore, miR-935 can be a new therapeutic candidate for OSCC treatment.
