Macrophage migration inhibitory factor (MIF) accounts for one of the first cytokine activities to have been described, and it has emerged recently to be an important regulator of innate and adaptive immunity. MIF is an upstream activator of monocytes/macrophages, and it is centrally involved in the pathogenesis of septic shock, arthritis, and other inflammatory conditions. The protein is encoded by a unique but highly conserved gene, and X-ray crystallography studies have shown MIF to define a new protein fold and structural superfamily. Although recent work has begun to illuminate the signal transduction pathways activated by MIF, the nature of its membrane receptor has not been known. Using expression cloning and functional analysis, we report herein that CD74, a Type II transmembrane protein, is a high-affinity binding protein for MIF. MIF binds to the extracellular domain of CD74, and CD74 is required for MIF-induced activation of the extracellular signal–regulated kinase–1/2 MAP kinase cascade, cell proliferation, and PGE2 production. A recombinant, soluble form of CD74 binds MIF with a dissociation constant of ∼9 × 10−9 K d, as defined by surface plasmon resonance (BIAcore analysis), and soluble CD74 inhibits MIF-mediated extracellular signal–regulated kinase activation in defined cell systems. These data provide a molecular basis for MIF's interaction with target cells and identify it as a natural ligand for CD74, which has been implicated previously in signaling and accessory functions for immune cell activation.

BackgroundAcquired radioresistance during radiotherapy is considered as the most important reason for local tumor recurrence or treatment failure. Circular RNAs (circRNAs) have recently been identified as microRNA sponges and involve in various biological processes. The purpose of this study is to investigate the role of circRNAs in the radioresistance of esophageal cancer.MethodsTotal RNA was isolated from human parental cell line KYSE-150 and self-established radioresistant esophageal cancer cell line KYSE-150R, and hybridized to Arraystar Human circRNA Array. Quantitative real-time PCR was used to confirm the circRNA expression profiles obtained from the microarray data. Bioinformatic tools including gene ontology (GO) analysis, KEGG pathway analysis and network analysis were done for further assessment.ResultsAmong the detected candidate 3752 circRNA genes, significant upregulation of 57 circRNAs and downregulation of 17 circRNAs in human radioresistant esophageal cancer cell line KYSE-150R were observed compared with the parental cell line KYSE-150 (fold change ≥2.0 and P < 0.05). There were 9 out of these candidate circRNAs were validated by real-time PCR. GO analysis revealed that numerous target genes, including most microRNAs were involved in the biological processes. There were more than 400 target genes enrichment on Wnt signaling pathway. CircRNA_001059 and circRNA_000167 were the two largest nodes in circRNA/microRNA co-expression network.ConclusionsOur study revealed a comprehensive expression and functional profile of differentially expressed circRNAs in radioresistant esophageal cancer cells, indicating possible involvement of these dysregulated circRNAs in the development of radiation resistance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-0977-7) contains supplementary material, which is available to authorized users.

BackgroundAcquired radioresistance has significantly compromised the efficacy of radiotherapy for esophageal cancer. The purpose of this study is to investigate the roles of epithelial-mesenchymal transition (EMT) and the Wnt/β-catenin signaling pathway in the acquirement of radioresistance during the radiation treatment of esophageal cancer.MethodsWe previously established a radioresistant cell line (KYSE-150R) from the KYSE-150 cell line (a human cell line model for esophageal squamous cell carcinoma) with a gradient cumulative irradiation dose. In this study, the expression of EMT phenotypes and the Wnt/β-catenin signaling pathway proteins were examined by real-time PCR, western blot and immunofluorescence in the KYSE-150R cells. The KYSE-150R cells were then treated with a β-Catenin/Tcf inhibitor FH535. The expressions of nuclear and cytoplasmic β-catenin and EMT markers in KYSE-150R cells were assessed at both mRNA and protein level after FH535 treatment. The radiosensitization effect of FH535 on KYSE-150R was evaluated by CCK8 analysis and a colony forming assay. DNA repair capacities was detected by the neutral comet assays.ResultsKYSE-150R cell line displayed obvious radiation resistance and had a stable genetic ability. EMT phenotype was presented in the KYSE-150R cells with decreased E-cadherin and increased snail and twist expressions. The up-regulated expressions of Wnt/β-catenin signaling pathway proteins (Wnt1, FZD1-4, GSK3β, CTNNB1 and Cyclin D1), the increased phosphorylation of GSK3β, and the decreased phosphorylation of β-catenin were observed in KYSE-150R cells compared with KYSE-150 cells, implicating the activation of the Wnt pathway in KYSE-150R cells. The expression of nuclear β-catenin and nuclear translocation of β-catenin from the cytoplasm was decreased after FH535 treatment. FH535 also reversed EMT phenotypes by increasing E-cadherin expression. The cell proliferation rates of KYSE-150R were dose-dependent and the radiation survival fraction was significantly decreased upon FH535 treatment. Neutral comet assays indicated that FH535 impairs DNA double stranded break repair in KYSE-150R cells.ConclusionsAcquisition of radioresistance and EMT in esophageal cancer cells is associated with the activation of the Wnt/β-catenin pathway. EMT phenotypes can be reduced and the radiosensitivity of esophageal cancer cells can be enhanced by inhibiting the Wnt/β-catenin pathway with FH535 treatment.

Radioresistance is considered as the most important reason for local tumour recurrence. This study investigates the role of miRNAs in radioresistant human esophageal cancer cells. Human miRNA microarray has been used to detect the differential expressed microRNAs between radioresistant esophageal cell line KYSE-150R and the parental cell line KYSE-150. The relative expression of some candidate miRNAs was measured by quantitative real-time PCR (qRT-PCR). Potential mRNA targets were analysed bioinformatically. Significant upregulation of 10 microRNAs and downregulation of 25 microRNAs were detected. The statistical significance of downregulation in hsa-miR-301a, hsa-miR-141 and hsa-miR-18b expression (P < 0.05) were confirmed by qRT-PCR. The correlation of the predicted microRNA target genes to apoptosis (63 genes), cell cycle (67 genes), DNA damage and repair (18 genes) were confirmed by functional annotation. The downregulation of hsa-miR-301a promoted radioresistance in KYSE-150R through the upregulation of wnt1, indicating that wnt/β-catenin signal pathway might be important in radioresistance. In conclusion, a unique set of miRNAs and their expression profiles in radiation resistance have been identified, providing a solid basis for future studies to investigate the target genes of these miRNAs and their function.

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Esophageal cancer (EC) is one of the leading causes of death among malignancies. Radiotherapy for esophageal squamous cell carcinoma (ESCC) patients is limited by resistance to ionizing radiation (IR). An increasing body of evidence has demonstrated that aberrant expression of microRNA-301a (miR-301a) contributes to cancer progression and sensitivity to radiation. The aim of the present study was to investigate the exact functions and potential mechanisms of miR-301a in ESCC radioresistance. Initially, the miR-301a-transfected radioresistant ESCC cells KYSE-150R exhibited a decreased proliferation rate, and enhanced radiosensitivity and migration, whereas downregulation of miR-301a in radiosensitive KYSE-150 cells produced the opposite results. miR-301a regulates WNT1 expression at both the mRNA and protein levels. Furthermore, dual-luciferase reporter assays revealed that WNT1 was a target gene of miR-301a. In addition, the expression of miR-301a markedly affected the expression of Wnt/β-catenin-related proteins such as β-catenin and cyclin D1. Finally, overexpression of miR-301a inhibited epithelial-mesenchymal transition (EMT) conversion by directly targeting Snail and vimentin in radioresistant-ESCC cell lines; however, no inhibitory effects were exerted on Twist. Collectively, these results indicated that miR-301a increased the radiosensitivity and inhibited the migration of radioresistant-ESCC cells by targeting WNT1, thereby inactivating the Wnt/β-catenin signaling pathway and EMT reversal. Thus, miR-301a may be a potential therapeutic target for the treatment of EC radioresistance.

Neutrophils are known to play a major role in the egg granulomatous lesions caused by Schistosoma japonicum, but the precise mechanism by which eggs recruit or active neutrophil is unknown. Here we report S. japonicum egg specific EF-hand protein-SjE16.7 is a potent neutrophil recruiter and initiates the egg associated inflammatory granuloma in schistosomiasis. We show that the expression of SjE16.7 at level of both mRNA and protein is restricted to the egg stage. It locates in the miracidium and subshell area of the egg and can be secreted by the egg. The antigenic properties of SjE16.7 strongly suggest a role for SjE16.7 as an egg-derived molecule involved in host-parasite interactions. To study SjE16.7 functions in vivo, we challenged murine air pouch with recombinant SjE16.7. The results showed SjE16.7 trigged more inflammatory cell infiltration than vehicle or control protein. Using peritoneal exudate neutrophils from mice, we found that SjE16.7 significantly induced neutrophil chemotaxis in vitro, and the observed phenotypes were associated with enhanced Rac GTPase activation in SjE16.7 treated cells. Finally, in vivo hepatic granuloma formation model showed SjE16.7 coupled beads recruited more inflammatory cell infiltration than control beads. Our findings suggest SjE16.7 is an important pathogenic factor derived from egg. By recruiting neutrophils and inducing local inflammation, SjE16.7 facilitates eggs to be excreted through gut tissues and also initiates pathology in the liver; therefore SjE16.7 is a possible target for the prevention and treatment of schistosomiasis.

Background and PurposeTo develop an artificial intelligence-based full-process solution for rectal cancer radiotherapy.Materials and MethodsA full-process solution that integrates autosegmentation and automatic treatment planning was developed under a single deep-learning framework. A convolutional neural network (CNN) was used to generate segmentations of the target and the organs at risk (OAR) as well as dose distribution. A script in Pinnacle that simulates the treatment planning process was used to execute plan optimization. A total of 172 rectal cancer patients were used for model training, and 18 patients were used for model validation. Another 40 rectal cancer patients were used for an end-to-end evaluation for both autosegmentation and treatment planning. The PTV and OAR segmentation was compared with manual segmentation. The planning results was evaluated by both objective and subjective assessment.ResultsThe total time for full-process planning without contour modification was 7 min, and an additional 15 min may require for contour modification and re-optimization. The PTV DICE similarity coefficient was greater than 0.85 for all 40 patients in the evaluation dataset while the DICE indices of the OARs also indicated good performance. There were no significant differences between the auto plans and manual plans. The physician accepted 80% of the auto plans without any further operation.ConclusionWe developed a deep learning-based automatic solution for rectal cancer treatment that can improve the efficiency of treatment planning.