KDM6B promotes ESCC cell proliferation and metastasis by facilitating C/EBPß transcription.

BACKGROUND: As an H3K27me3 demethylase and counteracts polycomb-mediated transcription repression, KDM6B has been implicated in the development and malignant progression in various types of cancers. However, its potential roles in esophageal squamous cell carcinoma (ESCC) have not been explored. METHODS: The expression of KDM6B in human ESCC tissues and cell lines was examined using RT-qPCR, immunohistochemical staining and immunoblotting. The effects of KDM6B on the proliferation and metastasis of ESCC were examined using in vitro and in vivo functional tests. RNA-seq and ChIP-seq assay were used to demonstrate the molecular biological mechanism of KDM6B in ESCC. RESULTS: We show that the expression level of KDM6B increased significantly in patients with lymph node metastasis. Furthermore, we confirmed that KDM6B knockdown reduces proliferation and metastasis of ESCC cells, while KDM6B overexpression has the opposite effects. Mechanistically, KDM6B regulates TNFA_SIGNALING_VIA_NFκB signalling pathways, and H3K27me3 binds to the promoter region of C/EBPß, leading to the promotion of C/EBPß transcription. Besides, we show that GSK-J4, a chemical inhibitor of KDM6B, markedly inhibits proliferation and metastasis of ESCC cells. CONCLUSIONS: The present study demonstrated that KDM6B promotes ESCC progression by increasing the transcriptional activity of C/EBPß depending on its H3K27 demethylase activity.

MiR-654-3p Suppresses Non-Small Cell Lung Cancer Tumourigenesis by Inhibiting PLK4.

PURPOSE: MiR-654-3p plays important roles in many types of malignant tumours. However, the biological function of miR-654-3p in non-small cell lung cancer (NSCLC) remains unknown. In this study, the role of miR-654-3p in NSCLC was investigated. METHODS: qRT-PCR was used to evaluate the level of miR-654-3p in NSCLC tissues and cell lines, while Cell Counting Kit-8, Annexin V/propidium iodide dual staining or TUNEL staining were used to investigate proliferation and apoptosis of NSCLC cells. Luciferase assays and Western blotting were performed to validate potential targets of miR-654-3p. RESULTS: MiR-654-3p levels were significantly decreased in NSCLC patients and cell lines and were significantly correlated with the tumour size and tumour node metastasis stage of NSCLC patients. In A549 cells, miR-654-3p overexpression significantly increased apoptosis and inhibited growth both in vivo and in vitro, while downregulation of miR-654-3p had the opposite effects. In addition, polo-like kinase 4 (PLK4) was shown to be a target gene of miR-654-3p that is negatively regulated by miR-654-3p in A549 cells. Furthermore, PLK4 was observed to be highly expressed in NSCLC tissues and cells, and PLK4 overexpression abolished the inhibitory effects of miR-654-3p overexpression on NSCLC cell proliferation. Finally, the animal experiment results further demonstrated that miR-654-3p inhibits tumour growth and regulates PLK4 expression. CONCLUSION: Our results demonstrate that miR-654-3p functions as a growth-suppressing miRNA by targeting PLK4 in NSCLC.

IL-6 and IL-8 secreted by tumour cells impair the function of NK cells via the STAT3 pathway in oesophageal squamous cell carcinoma.

BACKGROUND: Recurrence and metastasis are the leading causes of tumour-related death in patients with oesophageal squamous cell carcinoma (ESCC). Tumour-infiltrating natural killer cells (NK cells) display powerful cytotoxicity to tumour cells and play a pivotal role in tumour therapy. However, the phenotype and functional regulation of NK cells in oesophageal squamous cell carcinoma (ESCC) remains largely unknown. METHODS: Single cell suspensions from blood and tissue samples were isolated by physical dissociation and filtering through a 70 µm cell strainer. Flow cytometry was applied to profile the activity and function of NK cells, and an antibody chip experiment was used to identify and quantitate cytokine levels. We studied IL-6 and IL-8 function in primary oesophageal squamous carcinoma and NK cell co-cultures in vitro and by a xenograft tumour model in vivo. Western blotting was used to quantitate STAT3 (signal transducer and activator of transcription 3) and p-STAT3 levels. Finally, we performed an IHC array to analyse IL-6/IL-8 (interleukin 6/interleukin 8) expression in 103 pairs of tumours and matched adjacent tissues of patients with ESCC to elucidate the correlation between IL-6 or IL-8 and clinical characteristics. RESULTS: The percentages of NK cells in both peripheral blood and tumour tissues from patients with ESCC were significantly increased in comparison with those in the controls and correlated with the clinical characteristics. Furthermore, the decrease in activating receptors and increase in inhibitory receptors on the surface of tumour-infiltrating NK cells was confirmed by flow cytometry. The level of granzyme B, the effector molecule of tumour-infiltrating NK cells, was also decreased. Mechanistically, primary ESCC cells activated the STAT3 signalling pathway on NK cells through IL-6 and IL-8 secretion, leading to the downregulation of activating receptors (NKp30 and NKG2D) on the surface of NK cells. An ex vivo study showed that blockade of STAT3 attenuated the IL-6/IL-8-mediated impairment of NK cell function. Moreover, the expression of IL-6 or IL-8 in tumour tissues was validated by immunohistochemistry to be positively correlated with tumour progression and poor survival, respectively. CONCLUSIONS: Tumour cell-secreted IL-6 and IL-8 impair the activity and function of NK cells via STAT3 signalling and contribute to oesophageal squamous cell carcinoma malignancy.

[Expression of CLDN1 and Its Nuclear Distribution in Esophageal Squamous Carcinoma].

OBJECTIVE: To determine the expression of tight junction protein CLDN1 in esophageal squamous carcinoma (ESCC) and to explore the effect of CLDN1 on the biological function of ESCC TE-11 cells. METHODS: This study collected 30 ESCC tissues,30 adjacent normal tissues and 30 distal esophageal tissues to detected the expression of CLDN1 in tissue microaary by immunohistochemistry method. Western blot was employed to determine the expression of CLDN1 in 15 ESCC tissues and cell lines,and then the distribution of CLDN1 in tumor cells and normal esophageal epithelial cells was analyzed. Lentivirus containing the sequence of CLDN1 shRNA was constructed and transfected into TE-11 cells,the transfection efficiency and intracellular distribution was determined by Western blot and flow cytometry. Cell proliferation was detected by CCK-8,the invasion and migration ability of cells was determined with Transwell. Cytoskeleton changes was observed by laser scanning confocal microscope. RESULTS: Immunohistochemical results showed no significant difference between the cancer tissues and adjacent tissues in term of the positive rate of CLDN1 ( P>0.05). CLDN1 was highly expressed in highly and moderately differentiated ESCC tissues,but its expression was significantly decreased in poorly differentiated cancer tissues. Western blot revealed that CLDN1 was mainly distributed in the nucleus of TE-11 cells. The proliferation of TE-11 cells,as well as invasion and migration ability,were declined obviously when the expression of CLDN1 being down-regulated,while the cytoskeleton protein fluorescence intensity deceased. CONCLUSION: The expression of CLDN1 in ESCC tissue is associated with its differentiation and may promote carcinogenesis in TE-11 cells.

A bio-inspired synthesis of oxindoles by catalytic aerobic dual C-H functionalization of phenols.

Nitrogen-containing heterocycles are fundamentally important to the function of pharmaceuticals, agrochemicals and materials. Herein, we report a bio-inspired approach to the synthesis of oxindoles, which couples the energetic requirements of dehydrogenative C-N bond formation to the reduction of molecular oxygen (O2). Our method is inspired by the biosynthesis of melanin pigments (melanogenesis), but diverges from the biosynthetic polymerization. Mechanistic analysis reveals the involvement of CuII-semiquinone radical intermediates, which enable dehydrogenative carbon-heteroatom bond formation that avoids a catechol/quinone redox couple. This mitagates the deleterious polarity reversal that results from phenolic dearomatization, and enables a high-yielding phenolic C-H functionalization under catalytic aerobic conditions. Our work highlights the broad synthetic utility and efficiency of forming C-N bonds via a catalytic aerobic dearomatization of phenols, which is currently an underdeveloped transformation.