Systemic lupus erythematosus (SLE) is a complex autoimmune disease that is characterized by systemic inflammation and multiple organ failures. Dysregulation of T cells plays a critical role in SLE pathogenesis. Our previous study indicates that JKAP (also named DUSP22) inhibits T-cell activation and that JKAP knockout mice develop spontaneous autoimmunity; therefore, we investigated whether JKAP downregulation is involved in SLE patients. JKAP protein levels in purified T cells were examined by immunoblotting using blood samples from 43 SLE patients and 32 healthy controls. SLE patients showed significantly decreased JKAP protein levels in peripheral blood T cells compared to healthy controls. JKAP protein levels in peripheral blood T cells were inversely correlated with SLE disease activity index (SLEDAI) and anti-dsDNA antibody levels. JKAP downregulation in T cells was highly correlated with daily urinary protein amounts and with poor renal outcome in lupus nephritis patients. Notably, the diagnostic power of JKAP downregulation in T cells for active lupus nephritis was higher than those of serum anti-dsDNA antibody, C3, and C4 levels. Moreover, T-cell-specific transgenic mice expressing a dominant-negative JKAP mutant developed spontaneous autoimmune nephritis. Furthermore, JKAP-deficient T cells overproduced complement components, soluble ICAM-1, and soluble VCAM-1 in the kidney; these cytokines have been reported to be involved in lupus nephritis. Taken together, JKAP downregulation in T cells is a novel diagnostic and prognostic biomarker for SLE nephritis.
Growing evidence demonstrates that long noncoding RNAs (lncRNAs) are involved in the progression of various cancers, including hepatocellular carcinoma (HCC). The role of nuclear-enriched abundant transcript 1 (NEAT1), an essential lncRNA for the formation of nuclear body paraspeckles, has not been fully explored in HCC. We aimed to determine the expression, roles and functional mechanisms of NEAT1 in the proliferation and invasion of HCC. Based on real-time polymerase chain reaction data, we suggest that NEAT1 is upregulated in HCC tissues compared with noncancerous liver tissues. The knockdown of NEAT1 altered global gene expression patterns and reduced HCC cell proliferation, invasion and migration. RNA immunoprecipitation and RNA pull-down assays confirmed that U2AF65 binds to NEAT1. Furthermore, the study indicated that NEAT1 regulated hnRNP A2 expression and that this regulation may be associated with the NEAT1–U2AF65 protein complex. Thus, the NEAT1-hnRNP A2 regulation mechanism promotes HCC pathogenesis and may provide a potential target for the prognosis and treatment of HCC.
CD73 is a cell surface immunosuppressive enzyme involved in tumor progression and metastasis. While patients whose cancer cells express elevated CD73 are typically associated with an unfavorable outcome, the clinical impact of CD73 expression in patients with Head and neck squamous cell carcinoma (HNSCC) remains unclear. In the present study, we investigated the prognostic significance of CD73 in HNSCC using gene and protein expression analyses. Our results demonstrate that high levels of CD73 are significantly associated with reduced overall survival in patients with HNSCC. We also investigated the functional role of CD73 in vitro and demonstrated that CD73 promotes HNSCC migration and invasion through adenosine A3R stimulation and the activation of EGF/EGFR signaling. Moreover, in vivo xenograft studies demonstrated that CD73 promotes tumorigenesis. In conclusion, our study highlights a role for CD73 as a poor prognostic marker of patient survival and also as a candidate therapeutic target in HNSCCs.
A pretargeted oncologic positron emission tomography (PET) imaging that leverages the power of supramolecular nanoparticles with in vivo bioorthogonal chemistry was demonstrated for the clinically relevant problem of tumor imaging. The advantages of this approach are that (i) the pharmacokinetics (PKs) of tumor-targeting and imaging agents can be independently altered via chemical alteration to achieve the desired in vivo performance and (ii) the interplay between the two PKs and other controllable variables confers a second layer of control toward improved PET imaging. In brief, we utilized supramolecular chemistry to synthesize tumor-targeting nanoparticles containing transcyclooctene (TCO, a bioorthogonal reactive motif), called TCO⊂SNPs. After the intravenous injection and subsequent concentration of the TCO⊂SNPs in the tumors of living mice, a small molecule containing both the complementary bioorthogonal motif (tetrazine, Tz) and a positron-emitting radioisotope (64Cu) was injected to react selectively and irreversibly to TCO. High-contrast PET imaging of the tumor mass was accomplished after the rapid clearance of the unreacted 64Cu-Tz probe. Our nanoparticle approach encompasses a wider gamut of tumor types due to the use of EPR effects, which is a universal phenomenon for most solid tumors.
Cyclooxygenase-2 (COX-2) plays an important role in lung cancer development and progression. Using streptavidin-agarose pulldown and proteomics assay, we identified and validated Ku80, a dimer of Ku participating in the repair of broken DNA double strands, as a new binding protein of the COX-2 gene promoter. Overexpression of Ku80 up-regulated COX-2 promoter activation and COX-2 expression in lung cancer cells. Silencing of Ku80 by siRNA down-regulated COX-2 expression and inhibited tumor cell growth in vitro and in a xenograft mouse model. Ku80 knockdown suppressed phosphorylation of ERK, resulting in an inactivation of the MAPK pathway. Moreover, CBP, a transcription co-activator, interacted with and acetylated Ku80 to co-regulate the activation of COX-2 promoter. Overexpression of CBP increased Ku80 acetylation, thereby promoting COX-2 expression and cell growth. Suppression of CBP by a CBP-specific inhibitor or siRNA inhibited COX-2 expression as well as tumor cell growth. Tissue microarray immunohistochemical analysis of lung adenocarcinomas revealed a strong positive correlation between levels of Ku80 and COX-2 and clinicopathologic variables. Overexpression of Ku80 was associated with poor prognosis in patients with lung cancers. We conclude that Ku80 promotes COX-2 expression and tumor growth and is a potential therapeutic target in lung cancer.
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