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Hou G.Q.,Guangdong Medical College | Sun J.C.,Southern Medical University | Sun J.C.,Guangdong Province Key Laboratory of Molecular Tumor Pathology | Zhang X.J.,Southern Medical University | And 6 more authors.
American Journal of Neuroradiology

Our aim was to better understand and improve the accuracy of the preoperative diagnosis of intraspinal MM by a combined analysis of MR imaging and pathologic findings. All 5 patients had undergone unenhanced and contrast-enhanced MR imaging examinations. All tumor samples had immunohistochemical reactions to HMB-45, vimentin, S-100, EMA, and Leu-7 antibodies. All 5 cases were located in the intradural extramedullary compartment. Two cases had multifocal lesions, and 3 cases were solitary. Two cases showed homogeneously strong enhancement, and 3 cases showed moderate enhancement on contrast-enhanced T1WI. The tumor cells had positive reactions to HMB-45, vimentin, and S-100 antibodies. MR imaging plays an important role in the detection and diagnosis of intraspinal MM. Final diagnosis should be based on histopathology and IHC examinations. Source

Li Y.,Southern Medical University | Zeng Y.,Guangdong Province Key Laboratory of Molecular Tumor Pathology | Wang J.,Guangdong Province Key Laboratory of Molecular Tumor Pathology | Zhang X.,Guangdong Province Key Laboratory of Molecular Tumor Pathology | And 4 more authors.
Molecular Cancer Research

FMNL2 is a member of diaphanous-related formins that control actin-dependent processes such as cell motility and invasion. Its overexpression in metastatic cell lines and tissues of colorectal carcinoma has been associated with aggressive tumor development in our previous study. But its specific role in cancer is largely unknown. Here we report that FMNL2 is involved in epithelial-mesenchymal transition (EMT) maintenance in human colorectal carcinoma cells. A positive correlation between FMNL2 and vimentin expression and an inverse correlation between FMNL2 and E-cadherin expression were found in colorectal carcinoma cell lines and cancer tissues. Specific knockdown of FMNL2 led to an epithelial-state transition, confirmed by the cobblestone-like phenotype, upregulation of E-cadherin, α-catenin, and γ-catenin, and downregulation of vimentin, snail, slug. Loss of FMNL2 expression lowered the ability of TGF-β to induce cell invasion and EMT, as shown by morphology and the expression levels. Upregulation of vimentin, slug, snail, downregulation of E-cadherin and activation of receptor-Smad3 phosphorylation were observed in M5 and MDCK cells induced by TGF-β, whereas altered expression of these markers was not obvious in FMNL2-depleting M5 cells. High levels of activation of p-MAPK and p-MEK, but not p-PI3K and p-AKT, were observed in SW480/FMNL2+ cells compared with control cells. Treatment with U0126 could abrogate the activation of p-MAPK and p-MEK, whereas LY294002 treatment had no effect on the PI3K/AKT pathway. In conclusion, these findings identify a novel EMT and tumor promoting function for FMNL2, which is involved in TGF-β-inducedEMTand colorectal carcinoma cell invasion via Smad3 effectors, or in collaboration with MAPK/MEK pathway. ©2010 AACR. Source

Li Y.,Southern Medical University | Li Y.,Guangdong Province Key Laboratory of Molecular Tumor Pathology | Lv Z.,Southern Medical University | He G.,Southern Medical University | And 19 more authors.

Cancer stem cells (CSCs) and EMT-type cells, which share molecular characteristics with CSCs, have been believed to play critical roles in tumor metastasis. Although much progress has been garnered in elucidating the molecular pathways that trigger EMT, stemness and metastasis, a number of key mechanistic gaps remain elusive. In the study, miR-371-5p was obviously down-regulated in primary CRC tissues compared with matched adjacent normal mucosa and correlated significantly with differentiation, tumor size, lymphatic and liver metastases. MiR-371-5p could attenuate proliferation, invasion in vitro and metastasis in vivo in CRC cells. It also suppressed EMT by regulating Wnt/β-catenin signaling and strongly decreased the CRC stemness phenotypes. Moreover, demethylation of SOX17 induced miR-371-5p expression and consequently suppressed its direct target SOX2 in CRC cells. MiR- 371-5p was necessary for SOX17 mediated cancer-related traits and SOX2 was a functional target of miR-371-5p. A positive relationship between SOX17 and miR-371- 5p expression and a negative one between miR-371-5p and SOX2 expression were observed in CRC cell lines and tissues. In conclusion, we identified miR-371-5p as an important "oncosuppressor" in CRC progression and elucidated a novel mechanism of the SOX17/miR-371-5p/SOX2 axis in the regulation of EMT, stemness and metastasis, which may be a potential therapeutic target. Source

Wang J.,Southern Medical University | Wang J.,Luzhou Medical College | Zhu X.,Southern Medical University | Zhu X.,Guangdong Province Key Laboratory of Molecular Tumor Pathology | And 18 more authors.

DAB2IP has been identified as a tumor suppressor in several cancers but its oncogenic role and transcriptionally regulatory mechanisms in the progression of colorectal carcinoma (CRC) remain unknown. In this study, DAB2IP was downregulated in CRC tissues and a valuable prognostic marker for survival of CRC patients, especially in the late stage. Moreover, DAB2IP was sufficient to suppress proliferation, epithelial-mesenchymal transition (EMT), invasion and metastasis in CRC. Mechanically, the linear complex of EZH2/HDAC1/Snail contributed to DAB2IP silencing in CRC cells. The study further proved that the positive feedback loop between Snail and DAB2IP existed in CRC cells and DAB2IP was required for Snailinduced aggressive cell behaviors. Finally, DAB2IP correlated negatively with Snail and EZH2 expressions in CRC tissues. Our findings reveal the suppressive role and a novel regulatory mechanism of DAB2IP expression in the progression of CRC. DAB2IP may be a potential, novel therapeutic and prognostic target for clinical CRC patients. Source

Li X.,Southern Medical University | Li X.,Guangdong Province Key Laboratory of Molecular Tumor Pathology | Wang J.,Southern Medical University | Wang J.,Guangdong Province Key Laboratory of Molecular Tumor Pathology | And 8 more authors.
Annals of Surgical Oncology

Background: RhoGDI2 has been identified as a regulator of tumor metastasis but its role in cancer remains controversial. The aims of this study were to analyze the function of RhoGDI2 in colorectal carcinoma (CRC), and to determine its possible signaling pathway in CRC. Methods: The expression of RhoGDI2 was detected in CRC cell lines, and 20 matched pairs of fresh CRC tissues, and 120 cases of clinical paraffin-embedded CRC tissues by real-time RT-PCR, Western blot, RT-PCR, or immunohistochemistry. The levels of activations of p-PI3K, p-Akt, p-MAPK, and p-MEK were then examined in RhoGDI2-overexpressing cells by Western blot. A series of assays were finally performed to evaluate the effect of RhoGDI2 on CRC cell behaviors in vitro. Results: RhoGDI2 expression was higher in highly metastatic CRC cell lines than in lowly metastatic ones. RhoGDI2 expression was up-regulated in CRC or lymphatic metastatic tissues relative to normal mucosa (P < 0.05). RhoGDI2 expression was correlated strongly with tumor size, differentiation, and Duke's stage (P < 0.05). Patients with lower RhoGDI2 expression had better overall survival (P = 0.012), and RhoGDI2 could predict prognosis only in patients with early-stage disease. High levels of activations of p-PI3K and p-Akt were observed in RhoGDI2-overexpressing cells. LY294002 inhibitor could abrogate the activation of PI3K/Akt pathway in those cells. Over-expression of RhoGDI2 enhanced CRC cell proliferation, motility, and invasion in vitro. Conclusions: Over-expression of RhoGDI2 is associated with poor overall survival in CRC patients, especially those presenting in early-stage. RhoGDI2 contributes to cell proliferation, motility, and invasion of CRC, at least in part, by activating the PI3K/Akt pathway © 2011 Society of Surgical Oncology. Source

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