In recent decades, the multi-functional protein nucleolin (NCL) has been reported to express outside the nucleus of many cancer cells. However, the expression and role of the extra-nuclear NCL in esophageal squamous cell carcinoma (ESCC) were not well characterized. Here, NCL was detected by immunohistochemistry and Western blotting in 60 ESCC tissues. Further, the associations of NCL, EGFR, CXCR4 and Ki67 were analyzed by in vitro assays. Our results showed that NCL expression in all 40 cases of ESCC tissues with metastasis was extensively located in the nucleus, cytoplasm and cell membrane (extra-nucleus), while NCL expression in all 20 cases of ESCC without metastasis was merely limited into the nucleus (intra-nucleus).The extra-nuclear NCL expression was positively correlated with the expression of EGFR, CXCR4 and Ki67 and serves as an independent prognostic factor for ESCC patients. In vitro, NCL siRNA (si-NCL) efficaciously affected the expression of EGF or SDF-1-induced p-AKT, p-ERK and Ki67. Also, NCL siRNA inhibited the capacity of migration and invasion of ECA109 cells. In conclusions, our study suggests that NCL is implicated in the initiation and transduction of EGFR and CXCR4 signaling and further up-regulates Ki67 expression to modulate the biological behaviors of ESCC. Clinically, the extra-nuclear NCL expression can be used as an important indicator to determine metastasis and predict the prognosis, which help develop new therapeutic strategies against ESCC.
Background: Gastric tumors generally have a poor prognosis and molecular markers to improve early detection and predict outcomes are greatly needed. The present study reports that periostin (POSTN), a secretory protein that can alter the remodeling of the extracellular matrix, is highly expressed in gastric tumors.Materials and Methods: Gastric tissues were collected from patients at the Southern Medical University. These patients provided an informed consent and were approved by the institute. Normal, cancer, and metastatic gastric tissues from lymph nodes and tissues adjacent to the tumor were collected from patients diagnosed with gastric cancer. Results: Periostin expression gradually increased as the risk grade of the NIH classification increased, and this was closely correlated with disease-free survival and overall survival. Compared with adjacent normal gastric mucosa tissues, protein expression of POSTN in gastric cancer tissues and metastases was significantly higher by immunohistochemistry and Western blot analysis. In addition, POSTN was upregulated in advanced gastric cancer tissues than in early gastric cancer tissues.Moreover, the ectopic expression of POSTN in the immortalized human gastric cell line could increase the metastasis and invasion of gastric cancer cells. Conclusion: The present results could establish the significance of POSTN in driving oncogenesis and metastasis in gastric tumors, with implications for its potential use as a diagnostic or prognostic biomarker, and as a candidate therapeutic target.
K E Y W O R D Sbiomarker, gastric tumors, invasion, metastasis, periostin
Airway barrier damage and excessive inflammation induced by influenza A virus (IAV) are associated with disease progression and prognosis. ResolvinD1 (RvD1) is a promising lipid mediator with critical protection against infection in the lung. However, whether RvD1 protects against IAV-induced injury and the underlying mechanisms remain elusive. In this study, primary normal human bronchial epithelial (pNHBE) cells were isolated and co-cultured with IAV and/or RvD1. Then, the expressions of E-cadherin, Zonula occludins-1, inflammatory mediators and proteins in Nrf2-dependent pathway were detected. To further explore the mechanisms, Nrf2 short hairpin RNA (Nrf2 shRNA) was applied in pNHBE cells. Furthermore, mice were infected with IAV, and were subsequently treated with RvD1. We found that IAV downregulated expressions of E-cadherin, Zonula occludins-1, Nrf2 and HO-1, upregulated the phosphorylation of NF κ B p65 and IKBα, levels of IL-8 and TNF-α, as well as ROS production. RvD1 reversed these damaging effects induced by IAV. However, when Nrf2 expression was suppressed with shRNA in pNHBE cells, the protective effects of RvD1 on IAV-induced injury were inhibited. In vivo studies further demonstrated that RvD1 could alleviate barrier protein breakdown and reduce airway inflammatory reactions. Collectively, the study demonstrated that RvD1 could play dual beneficial roles in protecting airway epithelium barrier function and reducing inflammation via the Nrf2 pathway, which may provide a better treatment option for influenza A virus infection.
NADPH oxidase 4 (Nox4) is an important source of reactive oxygen species (ROS) production, and its expression is increased in lipopolysaccharide- (LPS-) stimulated lung epithelial cells. Polymerase δ-interacting protein 2 (Poldip2) has been proved to bind Nox4 and participates in oxidative stress and inflammation. However, the role of Poldip2/Nox4 in LPS-induced oxidative stress and inflammation in lung epithelial cells remains unclear. Cell viability was measured via MTT assays. The expression of Poldip2, Nox4, heme oxygenase-1 (HO-1), cyclooxygenase-2 (COX-2), AKT, and p-AKT was detected by Western blotting and/or immunofluorescence. Poldip2 and Nox4 interaction was analyzed via coimmunoprecipitation (Co-IP) assay. NADPH enzymatic activity and production of ROS, prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were assessed simultaneously. The small interfering RNA (siRNA) or plasmid targeting Nox4 was used to downregulate or upregulate Nox4, and the lentiviral vector encoding Poldip2 was used to downregulate or upregulate Poldip2. The present study demonstrated that LPS stimulation significantly increased the protein levels of Poldip2 and Nox4 and proved that Poldip2 interacted with Nox4 proved by Co-IP. Importantly, Poldip2 acted as an upstream regulator of Nox4. The increased expression of Nox4 and COX-2; NADPH enzymatic activity; production of ROS, PGE2, TNF-α, and IL-1β; and decreased HO-1 expression were significantly suppressed by lentiviral Poldip2 shRNA downregulation but were increased by lentiviral upregulation of Poldip2. Furthermore, inhibiting of PI3K-AKT signaling notably attenuated LPS-induced Poldip2/Nox4 activation. Our study demonstrated that Poldip2 mediates LPS-induced oxidative stress and inflammation via interaction with Nox4 and was regulated by the PI3K-AKT signaling. Targeting Poldip2 could be a beneficial therapeutic strategy for the treatment of ALI.
BackgroundAlthough many epidemiology studies have investigated the methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and their associations with lung cancer (LC), definite conclusions cannot be drawn. To clarify the effects of MTHFR polymorphisms on the risk of LC, we performed a meta-analysis in Chinese populations.Material/MethodsRelated studies were identified from PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure (CNKI), and Chinese Biology Medicine (CBM) until 16 February 2014. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations.ResultsA total of 11 studies with 2487 LC cases and 3228 controls were included in this meta-analysis. Overall, no significant association was found between MTHFR C677T polymorphism and LC risk when all studies in Chinese populations were pooled into this meta-analysis. In subgroup analyses stratified by geographical location and source of controls, significantly increased risk was found in North China (T vs. C: OR=1.28, 95% CI: 1.14–1.44; TT vs. CC: OR=1.67, 95% CI: 1.33–2.10; TT + CT vs. CC, OR=1.39, 95% CI=1.15–1.69; TT vs. CC + CT: OR=1.46, 95% CI: 1.03–2.06) and in population-based studies (TT vs. CC: OR=1.37, 95% CI: 1.14–1.65; TT vs. CC + CT: OR=1.25, 95% CI: 1.07–1.45).ConclusionsThis meta-analysis provides evidence that MTHFR C677T polymorphism may contribute to LC development in North China. Studies with larger sample sizes and wider spectrum of populations are warranted to verify this finding.
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