Motor neurons transplantation alleviates neurofibrogenesis during chronic degeneration by reversibly regulating Schwann cells epithelial-mesenchymal transition

A novel understanding of peripheral nerve injury is epithelial-mesenchymal transition (EMT), which characterizes the process of dedifferentiation and transformation of Schwann cells after nerve injury. Despite being regarded as an important mechanism for healing nerve injuries, long-term EMT is the primary cause of fibrosis in other tissue organs. The potential mechanism promoting neurofibrosis in the process of chronic degeneration of nerve injury and the effects of motor neurons (MNs) transplantation on neurofibrosis and repair of nerve injury were studied by transcriptome sequencing and bioinformatics analysis, which were confirmed by in vivo and in vitro experiments. Even 3 months after nerve injury, the distal nerve maintained high levels of transforming growth factor β-1 (TGFβ-1) and Snail family transcriptional repressor 2 (Snai2). The microenvironment TGFβ-1, Snai2 and endogenous TGFβ-1 formed a positive feedback loop in vivo and in vitro, which may contribute to the sustained EMT state and neurofibrogenesis in the distal injured nerve. Inhibiting TGFβ-1 and Snai2 expression and reversing EMT can be achieved by transferring MNs to distal nerves, and the removal of transplanted MNs is capable of reactivating EMT and promoting the growth of proximal axons. In conclusion, EMT persisting can be an explanation for distal neurofibrosis and a potential therapeutic target. By reversibly regulating EMT, MNs transplantation can alleviate neurofibrogenesis of distal nerve in chronic degeneration.

Fucoidan from Sargassum hemiphyllum inhibits the stemness of cancer stem cells and epithelial-mesenchymal transitions in bladder cancer cells

A variety of anticancer activities have been established for fucoidan from brown algae, whereas whether cancer stem cells (CSCs) are inhibited by sulfated polysaccharides is unexplored. In this study, fucoidan extracted from Sargassum hemiphyllum was showed heat stable and might tolerate 140 °C treatment. Fucoidan did not exhibit cytotoxicity in 5637 and T24 bladder cancer cells. After fucoidan treatment, the stress fibers were aggregated into thick and abundant underneath the plasma membrane and getting around the cells, and the structure of F-actin showed a remarkable change in the filopodial protrusion in T24 and 5637 cells. Using culture inserts, transwell assays and time lapse recordings showed that fucoidan inhibited cell migration. In the epithelial-mesenchymal transition (EMT), fucoidan downregulated the expression of vimentin, a mesenchymal marker, and upregulated the expression of E-cadherin, an epithelial marker. Additionally, the transcription levels of Snail, Slug, Twist1, Twist2, MMP2 and MMP9 were significantly decreased by fucoidan, indicating EMT suppression. CSCs are implicated in tumor initiation, metastatic spread, drug resistance and tumor recurrence. Our results showed that fucoidan inhibited stemness gene expression and sphere formation in bladder CSCs. For the first time, our findings demonstrated that fucoidan inhibits CSC formation and provides evidence as potential anticancer therapy.

Interferon-induced transmembrane protein 2 promotes epithelial-mesenchymal transition by activating transforming growth factor-β1/small mother against decapentaplegic 2 signaling in gastric cancer

BACKGROUND

Gastric cancer (GC) is one of the most prevalent malignancy around the world. Primary tumor cells are enabled to invade and migrate into adjacent normal tissues to form secondary tumors. Epithelial-mesenchymal transitions (EMT) plays a pivotal role in facilitating tumor progression. Abundant evidence suggested that the transforming growth factor-β1 (TGF-β1) triggered the process of EMT. Nonetheless, the precise molecular mechanisms underlying EMT requires further elucidation, and there still lacks effective specific therapeutic target. In our recent research, we demonstrated that the interferon (IFN)-induced transmembrane protein 2 (IFITM2) promoted the growth and metastasis of GC. However, it remains unclear whether IFITM2 involves in TGF-β1 mediated EMT in GC.

METHODS AND RESULTS

In the present research, we investigated the functional role of IFITM2 in EMT process and TGF-β1 signaling pathway in two GC cell lines. We noticed that silencing IFITM2 can effectively inhibit TGF-β1 signaling mediated EMT by regulating down stream small mother against decapentaplegic (SMAD) 2/3 and transcription factors.This finding was further determined in both tumor tissues from GC patients and normal tissues adjacent to cancer. Our data demonstrated the key role of IFITM2 in TGF-β1 signaling and EMT in GC.

CONCLUSION

The findings enriched our understanding of the underlying mechanism in EMT during the progression of GC. In addition, IFITM2 would be a potential target for treating GC and other malignant tumors.

[MicroRNA-133b suppresses cell proliferation and invasion of esophageal squamous cell carcinoma via downregulating TAGLN2 expression]

Objective: To investigate the expression of microRNA-133b (miR-133b) in esophageal squamous cell carcinoma (ESCC), and explore its effect and the underlying molecular mechanisms on cell proliferation and invasion. Methods: Real-time quantitative PCR (qPCR) was used to examine miR-133b expression in 63 ESCC tissues and paired adjacent non-cancerous tissues, several ESCC cells (Eca109, EC9706, EC1, TE1, KYSE70) and normal esophageal epithelial cell Het-1A. MiR-133b mimic, inhibitor and negative control (NC) were transfected into TE1 cells. The effect of miR-133b on cell proliferation and invasion were determined by CCK-8 and Transwell assays, respectively. Subsequently, the target gene of miR-133b was predicted by online tools TargetScan and miRDB, which was verified by dual luciferase reporter assays. Finally, Western blot was utilized to detect the effects of miR-133b overexpression on expression of target gene TAGLN2 as well as EMT-related proteins E-cadherin, N-cadherin, Snail, Slug and Vimentin. Results: Relative levels of miR-133b in ESCC tissues (0.295±0.040) were significantly lower than those in adjacent non-cancerous tissues (1.002±0.011, P<0.001). The expression of miR-133b was tightly associated with clinical staging, lymph node metastasis and prognosis. Moreover, relative levels of miR-133b in ESCC cells Eca109, EC9706, EC1, TE1 and KYSE70 (0.679±0.031, 0.391±0.008, 0.236±0.016, 0.031±0.005 and 0.099±0.020) were evidently lower than that in normal esophageal epithelial cell Het-1A (1.005±0.016, all P<0.001). In TE1 cells, miR-133b mimic significantly increased the level of miR-133b to 6.199±0.627, and suppressed cell proliferation and invasion, whereas miR-133b inhibitor obviously decreased its expression to 0.182±0.023, and promoted cell proliferation and invasion. Most notably, the relative luciferase activities of miR-133b-mimic group (0.320±0.018) in TE1 cells transfected with TAGLN-3'UTR-WT were markedly lower than that in NC group (1.010±0.036, P<0.001), whereas those in TAGLN-3'UTR-MUT transfection cells were 1.019±0.056 and 1.008±0.021, respectively, showing no significantly statistical difference (P>0.05). Furthermore, miR-133b overexpression markedly downregulated TAGLN2, N-cadherin, Snail, Slug and Vimentin levels, and increased E-cadherin expression. Conclusion: MiR-133b plays an important role in the proliferation and invasion of ESCC cells by regulating TAGLN2 expression, and it may be a potential therapeutic target for ESCC patients.

Predictive value of intratumour inflammatory cytokine mRNA levels of hepatocellular carcinoma patients and activation of two distinct pathways govern IL-8 induced epithelial-mesenchymal transition in human hepatic cancer cell lines

Hepatocellular carcinoma (HCC) is always accompanied by persistent inflammation of liver tissues, which is considered to exert protumourigenic effects by promoting cancer growth, progression, and metastasis. However, the tumour-promoting roles and predictive value of intratumoural inflammatory cytokines remain unclear. In the present study, we used database analysis, clinical pathological studies, and in vitro biological experiments on human hepatic cancer cell lines to assess the prognostic potential of the primary tumour cytokine mRNA levels and underlying mechanisms in HCC. First, we assessed the prognostic value of several cytokines from the TCGA database and found that IL-8 is a unique cytokine that is associated with poor overall survival of HCC patients. Then, we collected 87 HCC tumour and adjacent non-tumour specimens from patients and confirmed that patients with low IL-8 expression exhibited less intrahepatic invasion or distant metastasis, a lower recurrence rate and longer overall survival time compared to patients with high IL-8 expression. Wound healing, transwell, and western blotting assay results showed that IL-8 promotes the migration and invasion of Huh-7 and HepG2 cells, and the underlying mechanism is that IL-8 induces the EMT of HCC cells via the IL-8/ERK1/2/SNAI1 and IL-8/STAT3/TWIST1 signalling pathways. These results provide valuable biological IL-8 information which needs to be further investigated in liver cancer target therapy research. Furthermore, the intratumoural cytokine expression at the mRNA level may provide insight into hepatocarcinoma prognosis.

Histone deacetylase inhibitors upregulate Snail via Smad2/3 phosphorylation and stabilization of Snail to promote metastasis of hepatoma cells

Hepatocellular carcinoma (HCC) remains the third most common cause of cancer-related mortality. Resection and transplantation are the only curative treatments available, but are greatly hampered by high recurrence rates. Histone deacetylase inhibitors (HDACIs) are considered to be promising anticancer agents in drug development. Currently, four HDACIs have been granted Food and Drug Administration (FDA) approval for cancer. HDACIs have shown significant efficacy in hematological malignancies. However, they have limited effects in epithelial cell-derived cancers, including HCC, and the mechanisms of these are not elucidated. In this study, our results demonstrated that HDACIs were able to induce epithelial-mesenchymal transitions (EMT) in hepatoma cells which are believed to trigger tumor cell invasion and metastasis. We found that HDACIs promoted the expression of Snail and Snail-induced EMT was critical for HDACI-initiated invasion and metastasis. We indicated that HDACIs upregulated Snail in two ways. Firstly, HDACIs upregulated Snail at the transcriptional level by promoting Smad2/3 phosphorylation and nuclear translocation, then combined with the promoter to activate the transcription of Snail. Secondly, we showed that HDACIs regulated the stabilization of Snail via upregulating the expression of COP9 signalosome 2 (CSN2), which combined with Snail and exposed its acetylation site, then promoted acetylation of Snail, thereby inhibiting its phosphorylation and ubiquitination to repress the degradation of Snail. All these results highlighted that HDACIs have limited effects in HCC, and the use of HDACIs combined with other targeted strategies to inhibit EMT, which explored in this study is a promising treatment method for treating HCC.

Jumonji domain containing 2C promotes cell migration and invasion through modulating CUL4A expression in lung cancer

Jumonji domain containing 2C (JMJD2C), also named as KDM4C, was found to a transcriptional cofactor and enzyme that catalyzes demethylation of histone H3 lysine 9 and 36. Here in this study, we found that the expression of JMJD2C increased in a majority of the human lung cancer tissues examined compared with adjacent tissues. Furthermore, the expression of JMJD2C was found to be higher in metastatic lung cancer tissues than which in non-metastatic lung cancer tissues. Knockdown of JMJD2C inhibited the ability of migration and invasion of lung cancer cells. Moreover, JMJD2C knockdown was proven to inhibit the tumor hepatic metastasis of lung cancer cells in vivo and epithelial-mesenchymal transition (EMT) in vitro. On the contrary, over-expression of JMJD2C was found to promote the ability of migration, invasion and EMT. As to mechanism, knockdown of JMJD2C was found to inhibit the expression of CUL4A while to promote the expression of p53 and p27. Furthermore, we found that JMJD2C regulated the activities of lung cancer cells by directly controlling the expression of CUL4A in JMJD2C over-expression cell line, and interference of CUL4A was found to reverse the ability of migration, invasion and EMT which JMJD2C over-expression bought to. Together, these results of this study not only enriched the JMJD2C biological function of lung cancer, but also illuminated exploring the prevention and treatment of the invasion and metastasis of lung cancer.