TLR3, TLR4, TLR7 and TLR9 expression appears important to the biological pathogenesis of ESCC. TLRs may represent therapeutic targets for ESCC.

BackgroundMLL2 has been identified as one of the most frequently mutated genes in a variety of cancers including esophageal squamous cell carcinoma (ESCC). However, its clinical significance and prognostic value in ESCC has not been elucidated. In the present study, we aimed to investigate the expression and role of MLL2 in ESCC.MethodsImmunohistochemistry (IHC) and qRT-PCR were used to examine the expression profile of MLL2. Kaplan–Meier survival analysis and univariate and multivariate Cox analyses were used to investigate the clinical and prognostic significance of MLL2 expression in Kazakh ESCC patients. Furthermore, to evaluate the biological function of MLL2 in ESCC, we applied the latest gene editing technique CRISPR/Cas9 to knockout MLL2 in ESCC cell line Eca109. MTT, colony formation, flow cytometry, scratch wound-healing and transwell migration assays were performed to investigate the effect of MLL2 on ESCC cell proliferation and migration. The correlation between MLL2 and epithelial–mesenchymal transition (EMT) was investigated by Western blot assay in vitro and IHC in ESCC tissue, respectively.ResultsBoth mRNA and protein expression levels of MLL2 were significantly overexpressed in ESCC patients. High expression of MLL2 was significantly correlated with TNM stage (P = 0.037), tumor differentiation (P = 0.032) and tumor size (P = 0.035). Kaplan–Meier survival analysis showed that patients with low MLL2 expression had a better overall survival than those with high MLL2 expression. Multivariate Cox analysis revealed that lymph node metastasis and tumor differentiation were independent prognostic factors. Knockout of MLL2 in Eca109 inhibited cell proliferation and migration ability, induced cell cycle arrest at G1 stage, but it had no significant effect on apoptosis. In addition, knockout of MLL2 could inhibit EMT by up-regulation of E-Cadherin and Smad7 as well as down-regulation of Vimentin and p-Smad2/3 in ESCC cells. In cancer tissues, the expression of E-Cadherin was negatively correlated with MLL2 expression while Vimentin expression was positively correlated with MLL2 expression.ConclusionOur results indicate that overexpression of MLL2 predicts poor clinical outcomes and facilitates ESCC tumor progression, and it may exert oncogenic role via activation of EMT. MLL2 may be used as a novel prognostic factor and therapeutic target for ESCC patients.

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Thsd7a (Thrombospondin type 1 domain containing 7a) is a critical transmembrane protein. Studies have indicated that Thsd7a was associated with cytoskeletal organization, cell migration and filopodia formation. However, the involvement of Thsd7a remains elusive in human Esophageal Squamous Cell Carcinoma (ESCC). Consequently, immunohistochemistry and reverse transcription-polymerase chain reaction were utilized to study the correlation between the expression of Thsd7a and clinical-pathological characteristics. The influence of Thsd7a on apoptosis, cell proliferating activity, cell cycle, migratory and invasive capacity was determined in Eca 109 and EC 9706 cell lines in vitro. And the influence on proliferating activity was testified using naked mice model in vivo. In addition, the potential molecular mechanism was tested by microarray. It was discovered that there is a certain correlation between Thsd7a and the Kazakh ESCC. By knocking out Thsd7a, the invasion, migration and proliferation could be decreased. And it could also arrest the cell cycle at G1 phase and increase the apoptosis rate. It was further verified that Thsd7a had obvious effect on proliferation in naked mice with xenograft of Eca109 cells. Finally, it was uncovered by microarray analysis that a variety of tumor genes and pathways related to Thsd7a. Together, it was demonstrated that Thsd7a might have a certain degree of carcinogenesis in ESCC.

To evaluate the association of the plasma riboflavin level in Kazak esophageal cancer patients and their riboflavin transporter (C20orf54) gene statuses. Plasma riboflavin levels were detected by high performance liquid chromatography in Kazak patients with esophageal squamous cell carcinoma (ESCC) and healthy controls. C20orf54 mRNA and protein expression were analyzed by real-time fluorogenic quantitative polymerase chain reaction and immunohistochemistry in samples from 61 ESCC patients consisting of both tumor and normal tissue, respectively. C20orf54 mRNA expression was decreased in ESCC (0.279 ± 0.102) than in normal counterpart tissue (0.479 ± 0.287; P = 0.049) significantly. Tumors exhibited low C20orf54 protein expression (42.6, 26.2, 18.0 and 13.1% for no C20orf54 staining, weak staining, medium staining and strong staining, respectively), which was significantly lower than that in the normal mucous membrane (13.1, 26.2, 41.0 and 19.7% for no C20orf54 staining, weak staining, medium staining and strong staining, respectively). Defective expression of C20orf54 in tumor cells was significantly associated with poor differentiation. However, other parameters such as depth of invasion and lymph node metastasis had no significant relationship with C20orf54 expression. The average blood concentration of riboflavin was 2.6468 ± 1.3474 ng/ml in ESCC patients lower than control group (4.2960 ± 3.2293 ng/ml, P = 0.015). A positive correlation of plasma riboflavin levels with defective expression of C20orf54 protein was found in ESCC patients (F = 8.626; P = 0.038). Defective expression of C20orf54 is associated with the development of Kazak esophageal squamous cell carcinoma and this may represent a mechanism underlying the decreased plasma riboflavin levels in ESCC.