Shan Xing

The platform was simple and easy to operate, and this approach should be useful for the highly sensitive and versatile quantification of TEV proteins in clinical samples.

BACKGROUND: MicroRNAs (miRNAs) show considerable promise as therapeutic agents to improve tumor treatment, as they have been revealed as crucial modulators in tumor progression. However, our understanding of their roles in gastric carcinoma (GC) metastasis is limited. Here, we aimed to identify novel miRNAs involved in GC metastasis and explored their regulatory mechanisms and therapeutic significance in GC. METHODS: The microRNA expression profiles of GC tumors at different stages and at different metastasis statuses were compared respectively using the stomach adenocarcinoma (STAD) miRNASeq dataset in TCGA. Using the above method, miR-4521 was picked out for further study. miR-4521 expression in GC tissues was examined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and in situ hybridization (ISH). Highly and lowly invasive cell sublines were established using a repetitive transwell assay. Gain-of-function and loss-of-function analyses were performed to investigate the functions of miR-4521 and its upstream and downstream regulatory mechanisms in vitro and in vivo. Moreover, we investigated the therapeutic role of miR-4521 in a mouse xenograft model. RESULTS: In this study, we found that miR-4521 expression was downregulated in GC tissues compared with adjacent normal tissues and that its downregulation was positively correlated with advanced clinical stage, metastasis status and poor patient prognosis. Functional experiments revealed that miR-4521 inhibited GC cell invasion and metastasis in vitro and in vivo. Further studies showed that hypoxia repressed miR-4521 expression via inducing ETS1 and miR-4521 mitigated hypoxia-mediated metastasis, while miR-4521 inactivated the AKT/GSK3β/Snai1 pathway by targeting IGF2 and FOXM1, thereby inhibiting the epithelial-mesenchymal transition (EMT) process and metastasis. In addition, we demonstrated that therapeutic delivery of synthetic miR-4521 suppressed gastric carcinoma progression in vivo. CONCLUSIONS: Our results suggest an important role for miR-4521 in regulating GC metastasis and hypoxic response of tumor cells as well as the therapeutic significance of this miRNA in GC.

Predictive models for survival prediction in individual cancer patients following the tumor, node, and metastasis (TNM) staging system are limited. The survival rates of patients who share TNM stage diseases are diversified. Therefore, we established a nomogram in which hematological biomarkers and clinical characteristics for predicting the overall survival (OS) of nasopharyngeal carcinoma (NPC) patients were incorporated. The clinicopathological and follow-up data of 690 NPC patients who were histologically diagnosed histologically at the Sun Yat-sen University Cancer Center between July 2007 and December 2011 were retrospectively reviewed. Data was randomly divided into primary (n = 460) and validation groups (n = 230). Cox regression analysis was used to identify prognostic factors for building the nomogram in primary cohorts. The predictive accuracy and discriminative ability of the nomogram were measured by the concordance index (C-index) and decision curve, and were compared with the TNM staging system, Epstein-Barr virus DNA copy numbers (EBV DNA), or TMN stage plus EBV DNA. The results were internally validated by assessment of discrimination and calibration using the validation cohorts at the same institution. Independent factors selected into the nomogram for OS included age [hazard ratio (HR): 1.765; 95% confidence interval (CI): 1.008-3.090)], TNM stage (HR: 1.899; 95% CI: 1.023-3.525), EBV DNA (HR: 1.322; 95% CI: 1.087-1.607), lactate dehydrogenase level (LDH) (HR: 1.784; 95% CI: 1.032-3.086), high sensitivity C-reactive protein (hs-CRP) (HR: 1.840; 95% CI: 1.039-3.258), high-density lipoprotein cholesterol (HDL-C) (HR: 0.503; 95% CI: 0.282-0.896), hemoglobin (HGB) (HR: 0.539; 95% CI: 0.309-0.939) and lymphocyte to lymphocyte ratio (LMR) (HR:0.531; 95% CI: 0.293-0.962). The C-index in the primary cohort and validation cohort were 0.800 and 0.831, respectively, and were statistically higher when compared to C-index values for TNM stage (0.672 and 0. 716), EBV DNA (0.668 and 0.688), and TNM stage+ EBV DNA (0. 732 and 0. 760), P < 0.001 for all. Moreover, the decision curve analyses demonstrated that the nomogram model had a higher overall net benefit compared to the TNM staging system, EBV DNA and TNM stage+ EBV DNA. Next, patients were divided into three distinct risk groups for OS based on total points (TPs) of the nomogram: a low-risk group (TPs 19.0), an intermediate risk group (19.0 < TPs 25.5) and a high risk group (TPs > 25.5), respectively. The nomogram predicting prognosis generated for NPC patients had a higher predictive power compared to the TNM staging system, EBV DNA, and TNM stage+ EBV DNA.

UNLABELLED: Epstein-Barr virus (EBV) infection has been observed in tumor-infiltrated macrophages, but its infection effects on macrophage immune functions are poorly understood. Here, we showed that some macrophages in the tumor stroma of nasopharyngeal carcinoma (NPC) tissue expressed the immunosuppressive protein indoleamine 2,3-dioxygenase (IDO) more strongly than did tumor cells. EBV infection induced mRNA, protein, and enzymatic activity of IDO in human monocyte-derived macrophages (MDMs). Infection increased the production of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), whereas the neutralizing antibodies against TNF-α and IL-6 inhibited IDO induction. EBV infection also activated the mitogen-activated protein kinase (MAPK) p38 and NF-κB, and the inhibition of these two pathways with SB202190 and SN50 almost abrogated TNF-α and IL-6 production and inhibited IDO production. Moreover, the activation of IDO in response to EBV infection of MDMs suppressed the proliferation of T cells and impaired the cytotoxic activity of CD8(+) T cells, whereas the inhibition of IDO activity with 1-methyl-l-tryptophan (1-MT) did not affect T cell proliferation and function. These findings indicate that EBV-induced IDO expression in MDMs is substantially mediated by IL-6- and TNF-α-dependent mechanisms via the p38/MAPK and NF-κB pathways, suggesting that a possible role of EBV-mediated IDO expression in tumor stroma of NPC may be to create a microenvironment of suppressed T cell immune responses. IMPORTANCE: CD8(+) cytotoxic T lymphocytes (CTLs) play an important role in the control of viral infections and destroy tumor cells. Activation of the tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) in cancer tissues facilitates immune escape by the impairment of CTL functions. IDO expression was observed in some macrophages of the tumor stroma of nasopharyngeal carcinoma (NPC) tissue, and IDO could be induced in Epstein-Barr virus (EBV)-infected human monocyte-derived macrophages (MDMs). NPC cells and macrophages have been found to produce IDO in a gamma interferon (IFN-γ)-dependent manner. Instead, EBV-induced IDO expression in MDMs is substantially mediated by IL-6- and TNF-α-dependent mechanisms via the p38/MAPK and NF-κB pathways, which suppressed the proliferation of T cells and impaired the cytotoxic activity of CD8(+) T cells. This finding provides a new interpretation of the mechanism of immune escape of EBV and shows the immunosuppressive role of EBV-mediated IDO expression in tumor stroma of NPC.