Shaomin Li

The crucial role of miR-126 on suppressing progression of esophageal cancer by targeting VEGF-A

BackgroundmiR-126 is a key regulator of oncogenic processes. It is functionally linked to cellular proliferation, survival and migration. Vascular endothelial growth factor A (VEGF-A), which is regarded as a tumorgenesis activator, could directly target miR-126 in several tumors. However, the mechanism in esophageal cancer remains unclear.Methods and resultsIn this study, the expression of miR-126 and VEGF-A were assessed in esophageal cancer tissues and esophageal cancer cell lines. We found that miR-126 has significantly lower expression in esophageal cancer tissues and esophageal cancer cell lines than in healthy tissues, while the expression of VEGF-A is high. Luciferase reporter assays were performed to investigate the relationship between VEGF-A and miR-126. We confirmed that VEGF-A is a target for miR-126. Furthermore, the proliferation of esophageal cancer cells with miR-126 overexpression and miR-126 knockdown was monitored using the MTT assay. The results showed that miR-126 could inhibit esophageal cancer cell proliferation in vitro. The effect of miR-126 was also detected in BALB/c nude mice with transplanted esophageal cancer cells. In vivo study showed that tumor growth was significantly suppressed by miR-126 overexpression.ConclusionsWe believe that restoring miR-126 levels may be a promising therapeutic approach in cases of esophageal cancer.

Relationships of uPA and VEGF expression in esophageal cancer and microvascular density with tumorous invasion and metastasis.

OBJECTIVE To investigate uPA and VEGF expression in esophageal cancer and relations with tumorous invasion and metastasis. METHODS Immunohistochemistry was used to detect uPA and VEGF expression in the normal epithelial tissue of esophageal mucosa and cancer tissue and detect CD34 labeled micrangium and analyze the relationships with clinical pathological features and tumor angiogenesis. RESULTS Positive rates for uPA and VEGF protein expression were significantly greater in esophageal cancer than normal epithelial tissue (P < 0.05), the two being linked (P <0.05). In addition, uPA and VEGF protein expression of the high microvessel density (MVD) group was significantly lower than in the low MVD group (P < 0.05), with relation to clinical pathological staging, differentiation and lymph node metastasis (P < 0.05). CONCLUSION In esophageal cancer tissue, uPA and VEGF proteins are overexpressed and promote tumor angiogenesis, indicative of a poor prognosis.

O-linked N-acetylglucosamine transferase (OGT) is overexpressed and promotes O-linked protein glycosylation in esophageal squamous cell carcinoma

The aim of this present study was to explore the expression and clinical significance of O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) and enzymatic O-linked glycosylation (O-GlcNAcation) through the addition of O-linked-β-N-acetylglucosamine in esophageal squamous cell carcinoma. OGT expression and O-GlcNAcation in 40 samples from patients with esophageal squamous cell carcinoma was detected by immunohistochemical staining with anti-OGT antib ody and O-GlcNAc-specific antibody RL2, respectively. The relationship between pathological and clinical factors of patients was analyzed. We found that the expression of OGT was higher in esophageal squamous cell carcinoma samples compared to the normal tissues. RL2 antibody level was positively correlated with OGT expression, and the metastasis of lymph node, which means the level of O-GlcNAcation was high and related to the metastasis of lymph node in esophageal squamous cell carcinoma. In conclusion, OGT activation is the main reason for promoting the level of O-GlcNAcation in esophageal squamous cell carcinoma. O-GlcNAcylation may play an important role in esophageal squamous cell carcinoma.

Silencing NACK by siRNA inhibits tumorigenesis in non-small cell lung cancer via targeting Notch1 signaling pathway.

Non-small cell lung cancer (NSCLC) is the most common type of lung tumor with poor prognosis, in which the Notch signaling pathway plays an important role. Notch activation complex kinase (NACK) has been reported both as a co-activator and a target gene of the Notch pathway. However, the molecular mechanism of NACK in NSCLC still remains unknown. In this study, the expression of NACK was analyzed in 35 paired NSCLC tumor samples and 2 NSCLC cell lines. MTT assay, cell migration assay, cell invasion assay, flow cytometry assay, and xenograft model were employed to detect the effect of NACK knockdown on the cell proliferation, metastasis, invasion and apoptosis of NSCLC. The relationship between NACK and Notch1 signaling pathway in NSCLC cells was assessed by western blot and luciferase reporter assay. We found that the expression of NACK in the NSCLC tissues and lung cancer cells were significantly increased. High level of NACK expression is remarkable associated with tumor differentiation, lymphatic metastasis, clinical stage and poor survival prognosis. The interference of NACK significantly inhibited cell proliferation, invasion and metastasis through inducing apoptosis in NSCLC cells. The transcriptional activity of related Notch1 target genes were significantly suppressed resulting from NACK knockdown. This study demonstrates that interference of NACK inhibits NSCLC progression through Notch1 signaling pathway and targeting NACK may be an effective approach for NSCLC therapy.

Knockdown of DDX5 inhibits the proliferation and tumorigenesis in esophageal cancer.

DEAD (Asp-Glu-Ala-Asp) box protein 5 (DDX5), a prototypical member of the DEAD/H-box protein family, has been involved in several human malignancies. However, the expression and biological role of DDX5 in esophageal cancer (EC) remain largely unknown. In this study, we examined the role of DDX5 in regulating EC cell proliferation and tumorigenesis and explored its possible molecular mechanism. We found that DDX5 was overexpressed in human EC cell lines. In addition, knockdown of DDX5 significantly inhibited the proliferation of EC cells in vitro and the growth of EC xenografts in vivo. Knockdown of DDX5 also suppressed the migration/invasion and epithelial-to-mesenchymal transition (EMT) phenotype in EC cells. Furthermore, we observed that knockdown of DDX5 inhibited the expression of β-catenin, c-Myc, and cyclin D1 in EC cells. In conclusion, our findings provide the first evidence that siRNA-DDX5 inhibited the proliferation and invasion of EC cells through suppressing the Wnt/β-catenin signaling pathway. Therefore, DDX5 may be a novel potential therapeutic target for the prevention and treatment of EC.

PIK3CA gene mutations in Northwest Chinese esophageal squamous cell carcinoma

AIM To evaluate PIK3CA gene mutational status in Northwest Chinese esophageal squamous cell carcinoma (ESCC) patients, and examine the associations of PIK3CA gene mutations with clinicopathological characteristics and clinical outcome. METHODS A total of 210 patients with ESCC who underwent curative resection were enrolled in this study. Pyrosequencing was applied to investigate mutations in exons 9 and 20 of PIK3CA gene in 210 Northwest Chinese ESCCs. The associations of PIK3CA gene mutations with clinicopathological characteristics and clinical outcome were examined. RESULTS PIK3CA gene mutations in exon 9 were detected in 48 cases (22.9%) of a non-biased database of 210 curatively resected Northwest Chinese ESCCs. PIK3CA gene mutations were not associated with sex, tobacco use, alcohol use, tumor location, stage, or local recurrence. When compared with wild-type PIK3CA gene cases, patients with PIK3CA gene mutations in exons 9 experienced significantly better disease-free survival and overall survival rates. CONCLUSION The results of this study suggest that PIK3CA gene mutations could act as a prognostic biomarker in Northwest Chinese ESCC patients.

Endoscopic ultrasonography for preoperative staging of esophageal carcinoma

Abstract Objective: To evaluate the diagnostic value of endoscopic ultrasonography (EUS) in preoperative staging of esophageal carcinoma (EC). Material and methods: A total of 86 surgical patients with EC who were confirmed by endoscopy and biopsy underwent preoperative TN staging with EUS examination. The EUS findings were compared with surgical pathologic results. Results: The accuracy of EUS in T and N staging of EC was 82.6% and 84.9%, respectively. While determining whether EC invades the muscularis propria or outer membrane, EUS had the favorable sensitivity, specificity, positive predictive value and negative predictive value. The short-axis diameter of lymph nodes of 5mm had high sensitivity and negative predictive value to determine malignance with low specificity and positive predictive value. The short-axis diameter of 10mm presented the satisfactory sensitivity, specificity, positive predictive value and negative predictive value. Conclusion: EUS can accurately determine the TN staging of EC and provide a reliable basis for the treatment of EC.

p38 predicts depression and poor outcome in esophageal cancer

p38 mitogen-activated protein kinase (MAPK) signaling has been implicated in the cancer development and progression. However, the precise mechanism of this association remains unknown. The aim of the present study was to evaluate the association between p38 and cancer progression, including investigations into the effects on cell proliferation, resistance to thalidomide, indoleamine 2,3-dioxygenase (IDO) expression and prognosis in patients with esophageal cancer. The present retrospective study included patients with stage I–III esophageal cancer. A total of 228 patients with esophageal cancer were recruited to analyze the expression of phosphorylated (p)-p38 and IDO in tumor, and normal tissues through immunohistochemistry. Depression status was measured using the Zung Self-Rating Depression Scale. P38 cDNA was transfected into esophageal cancer cells to assess tumor cell viability, sensitivity to thalidomide treatment and IDO gene expression. Western blotting and flow cytometry was used to analyze protein expression alterations, and apoptosis in esophageal cancer cells. P-p38 protein was expressed in 68.9% of cancer tissues, and was significantly associated with depressive symptoms, tumor recurrence and poor survival of patients. In vitro experiments revealed that the expression of p-p38 induced esophageal cancer Eca-109 and TE-1 cell viability, and resistance to thalidomide treatment, as well as in the expression of IDO without the application of lipopolysaccharides. Further follow-up of patients revealed that depression was also an independent factor for early recurrence and overall survival rate. Altered p38 MAPK expression was associated with poor outcome in patients with esophageal cancer. p38 may be a potential biomarker for the prediction of depressive symptoms and prognosis in patients with esophageal cancer.

Downregulation of O-linked N-acetylglucosamine transferase by RNA interference decreases MMP9 expression in human esophageal cancer cells

O-linked N-acetylglucosamine transferase (OGT) catalyzes O-linked glycosylation (O-GlcNAcylation). O-GlcNAcylation is a post-translational carbohydrate modification of diverse nuclear and cytosolic proteins by the addition of O-linked β-N-acetylglucosamine. It was recently demonstrated that OGT and the level of O-GlcNAcylation are upregulated in esophageal cancer; however, the physiological consequences of this upregulation remain unknown. The current study reports that OGT knockdown by short hairpin RNA (shRNA) did not affect cell viability; however, cell migration in esophageal cancer Eca-109 cells was significantly reduced. OGT-specific shRNA vectors efficiently decreased the protein and mRNA levels of OGT and the RL2 level (a marker of O-GlcNAcylation levels) in Eca-109 esophageal cancer cells. In addition, colony formation and cell proliferation assays demonstrated that OGT-specific shRNA decreased the proliferation of Eca-109 cells; however, there was no significant statistical difference between OGT-specific shRNA and control shRNA. Notably, transwell assays demonstrated that the migratory ability of Eca-109 cells was significantly suppressed following knockdown of the OGT gene. Correspondingly, western blot analyses demonstrated that OGT knockdown significantly downregulated the expression of matrix metalloproteinase 9 (MMP9) in Eca-109 cells. These results suggest that OGT may promote the migration, invasion and metastasis of esophageal cancer cells by enhancing the stability or expression of MMP9.

MicroRNA‑361‑5p suppresses cancer progression by targeting signal transducer and activator of transcription 6 in non‑small cell lung cancer

The incidence of non-small cell lung cancer (NSCLC) has significantly increased in China, while the prognosis of affected patients is poor. The pathogenesis of NSCLC is thought to be regulated by microRNAs (miRs). The present study used a miR array in order to determine the expression of miR-361-5p, which was significantly lower in NSCLC tissues compared with that in adjacent tissues, indicating a crucial role of miR-361-5p during the progression of NSCLC. Furthermore, the effects of transfection-induced upregulation of miR-361-5p on the NSCLC cell line H23 were assessed. Overexpression of miR-361-5p inhibited the proliferation and colony formation ability of H23 cells. In addition, apoptosis of H23 cells was induced by upregulation of miR-361-5p. Furthermore, signal transducer and activator of transcription 6 (STAT6) was confirmed as a direct target of miR-361-5p by a dual-luciferase reporter assay. Moreover, inhibition of STAT6 by small interfering RNA or miR-361-5p also decreased the expression of B-cell lymphoma extra large (Bcl-xL). In vivo, miR-361-5p significantly reduced tumor growth in a nude mouse xenograft model, and suppressed STAT6 and Bcl-xL expression. In conclusion, the present study indicated that miR-361-5p may represent a novel molecular tool for therapeutic and diagnostic strategies in NSCLC.