SOX9 drives the epithelial-mesenchymal transition in non-small-cell lung cancer through the Wnt/ß-catenin pathway.

BACKGROUND: The distant metastasis of cancer cells is a risk factor for tumor lethality and poor prognosis in non-small-cell lung carcinoma (NSCLC). Increased SOX9 expression has been associated with clinical stage and poor prognosis in NSCLC, but the molecular mechanisms by which SOX9 promotes metastasis in NSCLC are still unknown. METHODS: The relationship between SOX9 expression and T, N, M classification was assessed using the χ2 test and Spearman's analysis in 142 immunohistochemically diagnosed specimens of NSCLC. We also generated SOX9-overexpression and SOX9-knockdown cells lines and their corresponding control cell lines by transfection with lentiviral constructs. In vivo assay, SOX9-overexpressing and SOX9-knockdown NSCLC cells were injected in zebrafish to examine distance metastasis. Gene set enrichment analysis (GSEA) was applied to analysis the correlation between SOX9 overexpression and Wnt/ß-catenin pathway. Luciferase assay was used to check transcriptional activity of TCF/LEF and western blot and immunofluorescence was employed to detect ß-catenin translocation in SOX9-overexpression, SOX9-knockdown and their corresponding control cell lines. RESULTS: We found that SOX9 overexpression correlates with the T, N and M stage significantly (p = 0.03, 0.000, and 0.032 respectively) in 142 immunohistochemically diagnosed specimens of NSCLC. SOX9 overexpression was found to decrease the expression of the epithelial cell markers E-cadherin and γ-catenin and increase the expression of the mesenchymal cell markers N-cadherin and vimentin. An in vivo assay showed distant metastasis of the SOX9-overexpressing cells, which was not observed in the SOX9-knockdown cells. These findings indicate that SOX9 promotes distant metastasis by promoting EMT in NSCLC cells. GSEA showed that SOX9 overexpression was significantly correlated with the Wnt/ß-catenin pathway which was corroborated by the expression of EMT-associated proteins in this pathway and its downstream target genes. SOX9 overexpression was also found to enhance the transcriptional activity of TCF/LEF, promote the nuclear translocation of ß-catenin and increase the phosphorylation of GSK3ß at Ser9. Further, inhibition of ß-catenin suppressed the metastasis-promoting effects of SOX9 overexpression. CONCLUSIONS: This study is the first to report that SOX9 is associated with clinical TNM stage and indicates that SOX9 promotes migration, invasion and the EMT process through the Wnt/ß-catenin pathway.

Risk factors for embolism in cardiac myxoma: a retrospective analysis.

BACKGROUND: Myxomas are the most common primary heart tumors and are closely associated with embolic events. Cardiac myxomas typically arise from the interatrial septum at the border of the fossa ovalis in the left atrium. Any other location is considered atypical. Embolism, one of the complications of myxoma, is associated with high morbidity and mortality. The aim of this study was to investigate the risk factors for embolism in patients with cardiac myxoma. MATERIAL AND METHODS: In this retrospective study, a cohort of 162 patients with cardiac myxomas was surgically treated between January 1998 and June 2014 at 3 cardiac centers in China. Preoperative data, including platelet count, sex, age, and the tumor (size, location, surface, and attachment), were compared between embolic and non-embolic groups of patients. RESULTS: No significant differences in vascular risk factors were seen between the 2 groups. However, the percentage of higher platelet count (>300 × 10(9)/L) and mean platelet volume in the embolic group were significantly higher than in the non-embolic group (P=0.0356, and 0.0113, respectively). Irregular surface and atypical location of the myxomas were also independently associated with increased risk of embolic complications. CONCLUSIONS: Tumor location, macroscopic appearance, mean platelet volume, and high platelet count are strong risk factors for embolic events in patients with cardiac myxomas.

Clinical significance of SOX9 in human non-small cell lung cancer progression and overall patient survival.

BACKGROUND: Sex determining region Y (SRY)-related high mobility groupbox 9 (SOX9) is an important transcription factor required for development, which regulates the expression of target genes in the associated pathway. The aim of this study was to describe the expression of SOX9 in human non-small cell lung cancer (NSCLC) and to investigate the association between SOX9 expression and progression of NSCLC. METHODS: SOX9 protein and mRNA expression in normal human pneumonocytes, lung cancer cell lines, and eight pairs of matched lung cancer tissues and their adjacent normal lung tissues were detected by Western blotting and real-time reverse transcription-polymerase chain reaction (RT-PCR). Immunohistochemistry was used to determine SOX9 protein expression in 142 cases of histologically characterized NSCLC. Statistical analyses were applied to test for prognostic and diagnostic associations. RESULTS: SOX9 in lung cancer cell lines was upregulated at both mRNA and protein levels, and SOX9 mRNA and protein were also elevated in NSCLC tissues compared with levels in corresponding adjacent non-cancerous lung tissues. Immunohistochemical analysis demonstrated a high expression of SOX9 in 74/142 (52.1%) paraffin-embedded archival lung cancer biopsies. Statistical analysis indicated that upregulation of SOX9 was significantly correlated with the histological stage of NSCLC (P=0.017) and that patients with a high SOX9 level exhibited a shorter survival time (P<0.001). Multivariate analysis illustrated that SOX9 upregulation might be an independent prognostic indicator for the survival of patients with NSCLC. CONCLUSIONS: This work shows that SOX9 may serve as a novel and prognostic marker for NSCLC, and play a role during the development and progression of the disease.