It has been reported that TNFR2 is involved in regulatory T cell induction and myeloid-derived suppressor cell (MDSC) accumulation, two kinds of immunosuppressive cells contributing to tumor immune evasion. Because transmembrane TNF-α (tmTNF-α) is the primary ligand for TNFR2, we hypothesized that tmTNF-α is mainly responsible for the activation of MDSCs. Indeed, we found that tmTNF-α, rather than secretory TNF-α (sTNF-α), activated MDSCs with enhanced suppressive activities, including upregulating arginase-1 and inducible NO synthase transcription, promoting secretion of NO, reactive oxygen species, IL-10, and TGF-β, and enhancing inhibition of lymphocyte proliferation. This effect of tmTNF-α was mediated by TNFR2, as TNFR2 deficiency significantly impaired tmTNF-α–induced release of IL-10 and NO and inhibition of T cell proliferation by MDSC supernatant. Furthermore, tmTNF-α caused p38 phosphorylation and NF-κB activation, whereas inhibition of NF-κB or p38 with an inhibitor pyrrolidine dithiocarbamate or SB203580 abrogated tmTNF-α–mediated increased suppression of lymphocyte proliferation by MDSCs. Consistently, our in vivo study showed that ectopic expression of uncleavable tmTNF-α mutant by 4T1 cells significantly promoted tumor progression and angiogenesis, accompanied with more accumulation of MDSCs and regulatory T cells in the tumor site, increased production of NO, IL-10, and TGF-β, as well as poor lymphocyte infiltration. In contrast, enforced expression of sTNF-α mutant by 4T1 cells that only released sTNF-α without expression of surface tmTNF-α markedly reduced MDSC accumulation and induced more lymphocyte infiltration instead, showing obvious tumor regression. Our data suggest that tmTNF-α acts as a potent activator of MDSCs via TNFR2 and reveals another novel immunosuppressive effect of this membrane molecule that promotes tumor immune escape.

Accumulation evidence shows that β-amyloid (Aβ) is a neurotoxic and accumulation of Aβ is responsible for the pathology of Alzheimer's disease (AD). However, it is currently not fully understood what makes Aβ toxic and accumulated. Previous studies demonstrate that Aβ is a suitable substrate for glycation, producing one form of the advanced glycation endproducts (AGEs). We speculated that Aβ-AGE formation may exacerbate the neurotoxicity. To explore whether the Aβ-AGE is more toxic than the authentic Aβ and to understand the molecular mechanisms, we synthesized glycated Aβ by incubating Aβ with methylglyoxal (MG) in vitro and identified the formation of glycated Aβ by fluorescence spectrophotometer. Then, we treated the primary hippocampal neurons cultured 8 days in vitro with Aβ-AGE or Aβ for 24 h. We observed that glycation exacerbated neurotoxicity of Aβ with upregulation of receptor for AGE (RAGE) and activation of glycogen synthase kinase-3 (GSK-3), whereas simultaneous application of RAGE antibody or GSK-3 inhibitor reversed the neuronal damages aggravated by glycated Aβ. Thereafter, we found that Aβ is also glycated with an age-dependent elevation of AGEs in Tg2576 mice, whereas inhibition of Aβ-AGE formation by subcutaneously infusion of aminoguanidine for 3 months significantly rescued the early cognitive deficit in mice. Our data reveal for the first time that the glycated Aβ is more toxic. We propose that the glycated Aβ with the altered secondary structure may be a more suitable ligand than Aβ for RAGE and subsequent activation of GSK-3 that can lead to cascade pathologies of AD, therefore glycated Aβ may be a new therapeutic target for AD.

Purpose. This study aims to explore the safety and efficacy of a novel treatment-intense pulsed light (IPL) in MGD eyes. Methods. This study is a prospective and open label study. Forty eyes of 40 MGD patients were recruited in the study and received 4 consecutive IPL treatments on day 1, day 15, day 45, and day 75. Ten ocular surface symptoms were evaluated with a subjective face score at every visit. Best spectacle corrected visual acuity, intraocular pressure (IOP), conjunctival injection, upper and lower tear meniscus height (TMH), tear break-up time (TBUT), corneal staining, lid margin and meibomian gland assessments, and meibography were also recorded at every visit, as well as the adverse effects on the eye and ocular surface. Results. Significant improvements were observed in single and total ocular surface symptom scores, TBUT, and conjunctival injection at all the visits after the initial IPL treatment (P < 0.05). Compared to baseline, the signs of eyelid margin, meibomian gland secretion quality, and expressibility were significantly improved at every visit after treatments. There was no regional and systemic threat observed in any patient. Conclusion. Intense pulsed light (IPL) therapy is a safe and efficient treatment in relieving symptoms and signs of MGD eyes.

P85α, which acts as a tumour suppressor, is frequently found to be downregulated in various human cancers. However, the role of p85α in the tumour microenvironment is unknown. Here, we report that aberrantly low expression of p85α in breast cancer stroma is clinically relevant to breast cancer disease progression. Stromal fibroblasts can acquire the hallmarks of cancer-associated fibroblasts (CAFs) as a result of the loss of p85α expression. Paracrine Wnt10b from p85α-deficient fibroblasts can promote cancer progression via epithelial-to-mesenchymal transition (EMT) induced by the canonical Wnt pathway. Moreover, exosomes have a key role in paracrine Wnt10b transport from fibroblasts to breast cancer epithelial cells. Our results reveal that p85α expression in stromal fibroblasts haves a crucial role in regulating breast cancer tumourigenesis and progression by modifying stromal–epithelial crosstalk and remodelling the tumour microenvironment. Therefore, p85α can function as a tumour suppressor and represent a new candidate for diagnosis, prognosis and targeted therapy.

TNF antagonists may offer therapeutic potential in solid tumors, but patients who have high serum levels of TNF-a fail to respond to infliximab, suggesting consumption of the circulating antibody and loss of transmembrane TNF-a (tmTNF-a) on tumors by ectodomain shedding. Addressing this possibility, we developed a monoclonal antibody (mAb) that binds both full-length tmTNF-a and its N-terminal truncated fragment on the membrane after tmTNF-a processing but does not cross-react with soluble TNF-a. We documented high levels of tmTNF-a expression in primary breast cancers, lower levels in atypical hyperplasia or hyperplasia, but undetectable levels in normal breast tissue, consistent with the notion that tmTNF-a is a potential therapeutic target. Evaluations in vitro and in vivo further supported this assertion. tmTNF-a mAb triggered antibodydependent cell-mediated cytotoxicity against tmTNF-a-expressing cells but not to tmTNF-a-negative cells. In tumor-bearing mice, tmTNF-a mAb delayed tumor growth, eliciting complete tumor regressions in some mice. Moreover, tmTNF-a mAb inhibited metastasis and expression of CD44v6, a prometastatic molecule. However, the antibody did not activate tmTNF-a-mediated reverse signaling, which facilitates tumor survival and resistance to apoptosis, but instead inhibited NF-kB activation and Bcl-2 expression by decreasing tmTNF-a-positive cells. Overall, our results established that tmTNF-a mAb exerts effective antitumor activities and offers a promising candidate to treat tmTNF-a-positive tumors, particularly in patients that are nonresponders to TNF antagonists. Cancer Res; 73(13); 4061-74. Ó2013 AACR.