Circular RNA hsa_circ_0023404 promotes proliferation, migration and invasion in non-small cell lung cancer by regulating miR-217/ZEB1 axis

BACKGROUND

Circular RNAs (circRNAs) have been considered as key regulators of cancer biology. However, the functional role of hsa_circ_0023404 in non-small cell lung cancer (NSCLC) and its regulatory mechanism are still almost unknown.

METHODS

The expression of hsa_circ_0023404, miR-217 and zinc finger E-box-binding homeobox 1 (ZEB1) was evaluated by quantitative real-time polymerase chain reaction. The role of hsa_circ_0023404 in NSCLC progression was determined using cell count kit-8 assay, transwell migration and invasion assay. Luciferase reporter assay was performed to assess the interaction of hsa_circ_0023404, miR-217 and ZEB1 in NSCLC cells.

RESULTS

The expression of hsa_circ_0023404 was upregulated in NSCLC tissues, as well as in NSCLC cell lines. High hsa_circ_0023404 expression predicted short overall survival in NSCLC. Functionally, knockdown of hsa_circ_0023404 inhibited the proliferation, migration and invasion of NSCLC cells. In the further molecular mechanism study, hsa_circ_0023404 was shown to interact with miR-217/ZEB1 axis to contribute to the growth of NSCLC cells.

CONCLUSION

hsa_circ_0023404 promotes the proliferation, migration and invasion of NSCLC cells by regulating miR-217/ZEB1 axis, providing a fresh perspective on circRNAs in NSCLC development.

miR-429 suppresses cell growth and induces apoptosis of human thyroid cancer cell by targeting ZEB1

Thyroid cancer is now the most common endocrine malignancy and the effect of miR-429 in the development of thyroid cancer still need to be further investigated. The expression level of miR-429 was quantified by qPCR in both clinical samples and cultured cell lines. MTT, flow cytometry, migration analyses and Matrigel invasion assays were conducted to test the proliferation, apoptosis, migration and invasion of MiR-429 transfection in thyroid cancer cell lines. Luciferase activity assay and western blot were conducted to detect the direct effect of miR-429 on Zinc finger E-box-binding homeobox 1 (ZEB1) expression. In this study, it was found that miR-429 was frequently decreased in thyroid cancer tissues and cell lines. Transfection of miR-429 in thyroid cancer cell lines substantially suppressed cell proliferation, migration and invasion. Besides, miR-429 up-regulation would induce apoptosis in different cell lines. ZEB1 was identified as a direct target of miR-429 and miR-429 transfection could inhibit ZEB1 by direct binding to its 3'-untranslated region (3'-UTR). In conclusion, these data indicated that miR-429 could act as a tumour suppressor miRNA and contribute to the development and progression and metastasis of thyroid cancer.

Neogenin-1 Promotes Cell Proliferation, Motility, and Adhesion by Up-Regulation of Zinc Finger E-Box Binding Homeobox 1 Via Activating the Rac1/PI3K/AKT Pathway in Gastric Cancer Cells

BACKGROUND/AIMS

Neogenin-1 (Neo1) has been reported to be involved in diverse physiology and pathology functions, including cell proliferation, differentiation and migration. The present study aimed to explore the functional role of neogenin-1 (Neo1) in gastric cancer (GC), together with underlying mechanisms.

METHODS

Neo1 expression was analyzed by qRT-PCR and Western blot analysis in both human GC cell lines and normal gastric epithelial cell line. Neo1 was respectively overexpressed or silenced by transfection with pcDNA3.1 or siRNA, and then the cells were incubated with or without different concentrations of cisplatin, transforming growth factor (TGF)-β1, and/or inhibitors of Rac-1 and PI3K. Thereafter, cell viability, invasion, and adhesion were measured by CCK-8, wound healing and adhesion assays, respectively. The expression levels of key factors involved in epithelial mesenchymal transition (EMT) and the PI3K/AKT pathway were analyzed by Western blot analysis.

RESULTS

The results showed that the Neo1 level was significantly increased in GC cell lines, with the highest level in SGC-7901 cells. Overexpression of Neo1 significantly reduced the GC cell sensitivity to cisplatin and increased the cell viability, motility and adhesion ability, and while silencing of Neo1 showed contrary results. Moreover, overexpression of Neo1 dramatically downregulated the E-Cadherin level and upregulated the levels of N-Cadherin and Vimentin. In addition, the data revealed that Neo1 positively regulated the expression of Zinc finger E-box-binding homeobox 1 (ZEB1) by activating the Rac1/PI3K/AKT pathway.

CONCLUSIONS

Neo1 could promote cell proliferation, motility, and adhesion by up-regulation of ZEB1 via activating the Rac1/PI3K/AKT pathway in GC cells.

MicroRNA-200C and -150 play an important role in endothelial cell differentiation and vasculogenesis by targeting transcription repressor ZEB1

To investigate the role of miRNA in controlling human embryonic stem (hES) cell differentiation toward the endothelial lineage and chick embryonic blood vessel formation, undifferentiated hES cells were first cultured on Matrigel-coated flasks and in endothelial cell growth medium-2 (EGM-2) to initiate endothelial cell (EC) differentiation. CD146(+) cells were isolated from differentiating hES cells and expanded in vitro. The in vitro expanded CD146(+) cells were positive for EC markers, capable of Ac-LDL uptake, lectin binding, and the formation of vascular structures in vitro and in vivo. miRNA gain/loss-of-function analyses revealed that miR-150 and miR-200c were crucial in EC differentiation. Transcriptional repressor zinc finger E-box-binding homeobox 1 (ZEB1) was identified as the communal target gene of miRNA-200C and -150, and inhibition of ZEB1 was required for miRNA-200C or -150 mediated EC gene expressions. Moreover, we demonstrated that ZEB1 could transcriptionally repress EC gene expression through direct binding to promoters of EC genes. Finally, we also demonstrated that miRNA-200c and -150 played an important role in chick embryonic blood vessel formation by in vivo inhibition of miRNA-200C or -150 in developing chick embryos, and blocking ZEB1 signaling in CD146-positive cells could rescue the inhibitory effects of miR-200c inhibiton in in vivo vasculogenesis. Our findings revealed that miR-150 and miR-200c play an important role in human endothelial lineage specification and chick embryonic vasculogenesis by targeting ZEB1.

Deadly crosstalk: Notch signaling at the intersection of EMT and cancer stem cells

Notch signaling is an evolutionarily conserved pathway involved in cell fate control during development, stem cell self-renewal and postnatal tissue differentiation. Roles for Notch in carcinogenesis, in the biology of cancer stem cells, tumor angiogenesis and epithelial-to-mesenchymal transition (EMT) have been reported. This mini-review describes the role of Notch signaling deregulation in EMT and tumor aggressiveness. We describe how accumulated evidence suggests that Notch inhibition is an attractive strategy for the treatment of several cancers, at least in part because of its potential to reverse or prevent EMT.