APLNR is involved in ATRA-induced growth inhibition of nasopharyngeal carcinoma and may suppress EMT through PI3K-Akt-mTOR signaling.

The apelin receptor (APLNR) is a GPCR involved in many pathophysiological processes; however, the correlation between APLNR expression and nasopharyngeal carcinoma (NPC) has not been reported. In this study, we used cDNA microarray data to determine APLNR expression levels in NPC tissues. We found that APLNR expression was reduced in NPC tissues compared with noncancerous nasopharyngeal epithelial tissues. Subsequently, a large-scale sample of 1015 tissues was used to validate this discovery and explore the relationship between APLNR expression and prognosis of NPC. Expression levels of APLNR in NPC tissues were indeed down-regulated. Furthermore, positive expression of APLNR in NPC predicted a better prognosis (disease-free survival: P = 0.001; overall survival: P < 0.001). Moreover, ingenuity pathway analysis revealed that an indirect interaction existed between APLNR and retinoic acid (RA) in the cancer regulatory network. Consistently, after treatment with all-trans-RA (ATRA), we found that APLNR was significantly up-regulated in NPC cell lines (5-8F and HNE1), and proliferation of NPC cells was inhibited. Cell cycle arrest occurred in the G0/G1 phase. In contrast, knockdown of APLNR diminished ATRA-induced growth inhibition of NPC cells. In addition, we surprisingly found that APLNR also played an important role in migration and invasion of NPC. Wound-healing and Transwell assays revealed that APLNR overexpression led to reduced migratory and invasive properties in 2 NPC cell lines. Western blot results revealed that hallmarks of epithelial-mesenchymal transition (EMT) were altered as well, suggesting that APLNR was capable of inhibiting EMT in NPC cells. Our study further demonstrated that low expression of APLNR promoted EMT in NPC cells by activating the PI3K-protein kinase B-mammalian target of rapamycin signaling pathway. Taken together, our data suggest that APLNR could potentially predict prognosis for patients with NPC and inhibit proliferation, migration, invasion, and EMT in nasopharyngeal cancer cells.-Liu, Y., Liu, Q., Chen, S., Liu, Y., Huang, Y., Chen, P., Li, X., Gao, G., Xu, K., Fan, S., Zeng, Z., Xiong, W., Tan, M., Li, G., Zhang, W. APLNR is involved in ATRA-induced growth inhibition of nasopharyngeal carcinoma and may suppress EMT through PI3K-Akt-mTOR signaling.

Upregulation of cyclin D1 can act as an independent prognostic marker for longer survival time in human nasopharyngeal carcinoma.

BACKGROUND: Cyclin D1 is an essential part of oncogenic transformation. We previously proved that cyclin D1 was upregulated in nasopharyngeal carcinoma (NPC) and promoted the NPC cell proliferation. But the association between cyclin D1 and the clinical outcome of NPC has not yet been determined. The study explores the possible relevance between the cyclin D1 expression and clinical parameters and its predictive value of prognosis in NPC patients. METHODS: We analyzed the clinical data from 379 NPC patients and 112 non-NPC patients in our previous study, which made further statistics. Receiver operating curve (ROC) was applied to select the optimal cutoff points. By analyzing the clinical data from 101 NPC patients using Chi-squared test, we estimated the relationship between the cyclin D1 expression level and clinicopathological parameters. We also used Kaplan-Meier method and log-rank test assess and compared the disease-free survival (DFS) rate and overall survival (OS) rate. The Cox proportional hazards model was adopted to perform the univariate and multivariate analyses. RESULT: Receiver operating curve analysis reported that cyclin D1 was used to differentiate between NPC patients and non-NPC patients (P < .001, sensitivity: 53.6%, specificity: 85.7%, AUC = 0.752). Cyclin D1 was positively correlated with lymph node metastasis (P = .015). A survival analysis of the 101 NPC patients indicated that the positive expression of cyclin D1 was predictive of a good prognosis (DFS: P = .010, OS: P = .019). Multivariate analysis showed that cyclin D1 could be used independently to predict NPC patients' prognosis (DFS: P = .038). CONCLUSION: The overexpression of cyclin D1 is a good prognostic marker for NPC.

Sequential Detection of Superoxide Anion and Hydrogen Polysulfides under Hypoxic Stress via a Spectral-Response-Separated Fluorescent Probe Functioned with a Nitrobenzene Derivative.

Chronic hypoxic stress disrupts the intracellular redox homeostasis, leads to a series of physiological dysfunction, and finally results in many diseases including cancer and inflammatory and cardiovascular diseases. The intracellular redox status is related to the homeostasis between reactive oxygen species (ROS) and cellular antioxidant species. Superoxide anion (O2•-) is considered to be a precursor of ROS. As a member of reactive sulfur species, hydrogen polysulfides (H2S n) are a class of antioxidants in cells, which act as an important regulator for the intracellular redox state. Therefore, trapping the cross-talk of O2•- and H2S n is a benefit for further understanding the physiological and pathological effects. Herein, we conceive a fluorescent probe HCy-ONO for sequential detection of O2•- and H2Sn in cells and in mouse models. Based on a tandem reaction, the probe HCy-ONO can be used to detect O2•- and H2S n in different fluorescence collection windows without spectral overlap interference with limits of detection 90 and 100 nM, respectively. The strategy affords high sensitivity and selectivity for our detection in living cell models under continuous hypoxic and intermittent hypoxic conditions, revealing the reason for ischemia-reperfusion injury. Moreover, the probe can distinguish the inflamed tissue from normal tissue in acute peritonitis mouse model. Finally, our probe is successfully applied for imaging of O2•- and H2S n in the SH-SY5Y tumor-bearing mouse model, which is helpful to elucidate the physiological and pathological processes. These data demonstrated that different hypoxic status lead to different concentrations between H2S n and O2•-.

PLUNC inhibits invasion and metastasis in nasopharyngeal carcinoma by inhibiting NLRP3 inflammasome activation.

Nasopharyngeal carcinoma (NPC) is a malignant tumor that occurs in the nasopharynx. Palate, lung, and nasal epithelium clone (PLUNC) has been identified as an early secreted protein that is specifically expressed in the nasopharynx. The aim of this study was to determine the role and mechanism of PLUNC in NPC. We used mRNA sequencing (seq) combined with ribosome-nascent chain complex (RNC)-seq to determine the biological role of PLUNC. The expression of epithelial-to-mesenchymal transition (EMT)-related molecules was detected by western blotting. Then, cell migration and invasion were detected by wound healing and Transwell chamber assays. NPC cells were injected into the tail vein of nude mice to explore the biological role of PLUNC in vivo. The sequencing results showed that PLUNC inhibited the progression of NPC and its expression was correlated with that of NOD-like receptors. Experiments confirmed that PLUNC inhibited the invasion and metastasis of NPC cells by promoting the ubiquitination degradation of NLRP3. PLUNC overexpression in combination with the treatment by MCC950, an inhibitor of NLRP3 inflammasome activation, was most effective in inhibiting NPC invasion and metastasis. In vivo experiments also confirmed that the combination of PLUNC overexpression and MCC950 treatment effectively inhibited the lung metastasis of NPC cells. In summary, our research suggested that PLUNC inhibited the invasion and metastasis of NPC by inhibiting NLRP3 inflammasome activation, and targeting the PLUNC-NLRP3 inflammasome axis could provide a new strategy for the diagnosis and treatment of NPC patients.

The Multifunctional Roles of Short Palate, Lung, and Nasal Epithelium Clone 1 in Regulating Airway Surface Liquid and Participating in Airway Host Defense.

Short palate, lung, and nasal epithelium clone 1 (SPLUNC1) is a kind of secretory protein, and gets expressed abundantly in normal respiratory epithelium of humans. As a natural immune molecule, SPLUNC1 is proved to be involved in inflammatory response and airway host defense. This review focuses on summarizing and discussing the role of SPLUNC1 in regulating airway surface liquid (ASL) and participating in airway host defense. PubMed and MEDLINE were used for searching and identifying the data in this review. The domain of bactericidal/permeability-increasing protein in SPLUNC1 and the α-helix, α4, are essential for SPLUNC1 to exert biological activities. As a natural innate immune molecule, SPLUNC1 plays a significant role in inflammatory response and airway host defense. Its special expression patterns are not only observed in physiological conditions, but also in some respiratory diseases. The mechanisms of SPLUNC1 in airway host defense include modulating ASL volume, acting as a surfactant protein, inhibiting biofilm formation, as well as regulating ASL compositions, such as LL-37, mucins, Neutrophil elastase, and inflammatory cytokines. Besides, potential correlations are found among these different mechanisms, especially among different ASL compositions, which should be further explored in more systematical frameworks. In this review, we summarize the structural characteristics and expression patterns of SPLUNC1 briefly, and mainly discuss the mechanisms of SPLUNC1 exerted in host defense, aiming to provide a theoretical basis and a novel target for future studies and clinical treatments.

Gold nanorods functionalized by a glutathione response near-infrared fluorescent probe as a promising nanoplatform for fluorescence imaging guided precision therapy.

Theranostics nanoplatforms offer opportunities for imaging-guided precision therapy and hold great potential for clinical applications. In most reported works, the imaging unit has a lack of site selectivity, and is always kept in the "on" modality regardless of whether it is in normal tissues or tumor sites, increasing the risk of unsafe treatment. Herein, we designed a near-infrared (NIR) fluorescence-guided theranostics nanoplatform by integrating the functions of tumor-response and photodynamic therapy (PDT)/photothermal therapy (PTT). A novel NIR fluorescent dye, CyPT, with excellent optical and PDT/PTT properties, was synthesized and linked onto the gold nanorods (AuNRs) to form CyPT-AuNRs nanohybrids via a sulfur-sulfur bond that can be broken by glutathione (GSH) with high selectivity and sensitivity. In normal cells where the concentration of GSH is low, the fluorescence of CyPT is quenched by the AuNRs. By contrast, the high level of GSH in tumor cells leads to the breaking of the sulfur-sulfur bond, resulting in the release of CyPT and the accomplishment of a "off-on" fluorescence response. Followed by precise NIR tumor-imaging diagnosis, the PDT and PTT treatment which rely on the released CyPT and AuNRs, respectively, can be effectively performed. The CyPT-AuNRs nanoplatform has been successfully applied to the treatment of tumor xenograft models and no distinct damage has been observed in the nearby normal tissues. This versatile nanoplatform has potential for use in targeted tumor imaging and precision therapy.