MicroRNA-488 inhibits tongue squamous carcinoma cell invasion and EMT by directly targeting ATF3

Abstract Background It has been reported that the expression of activating transcription factor 3 (ATF3) is closely associated with both microRNA (miRNA) processing and the progress of many cancers. Our study aimed to explore the interaction between ATF3 and miR-488 in tongue squamous cell carcinoma (TSCC). Methods Quantitative real-time PCR was performed to detect the levels of ATF3 and miR-488 in TSCC tissues and cell lines. Cell invasion and epithelial–mesenchymal transition (EMT) were assessed to determine the biological functions of miR-488 and ATF3 in TSCC cells. The mRNA and protein levels of ATF3 were measured using quantitative RT-PCR and western blotting. Luciferase assays were performed to validate ATF3 as an miR-488 target in TSCC cells. Results We found that the level of miR-488 significantly decreased and the expression of ATF3 significantly increased in TSCC tissues and cell lines. A low level of miR-488 was closely associated with increased expression of ATF3 in TSCC tissues. Introducing miR-488 significantly inhibited the invasion and EMT of TSCC cells, and knockdown of miR-488 promoted both processes. The bioinformatics analysis predicted that ATF3 is a potential target gene of miR-488. The luciferase reporter assay showed that miR-488 could directly target ATF3. ATF3 silencing had similar effects to miR-488 overexpression on TSCC cells. Overexpression of ATF3 in TSCC cells partially reversed the inhibitory effects of the miR-488 mimic. Conclusion miR-488 inhibited cell invasion and EMT of TSCC cells by directly downregulating ATF3 expression

MiR-106a directly targets LIMK1 to inhibit proliferation and EMT of oral carcinoma cells

Abstract Background LIM kinase 1 (LIMK1) expression levels are closely associated with microRNA (miRNA) processing. Higher levels of LIMK1 are reported during the progression of many cancers. Our study explored the interaction between LIMK1 and miR-106a in oral squamous cell carcinoma (OSCC). Methods Quantitative RT-PCR was performed to detect the levels of LIMK1 and miR-106a in OSCC tissues and cell lines. The rates of cell proliferation and epithelial–mesenchymal transition (EMT) were assessed to determine the biological functions of miR-106a and LIMK1 in OSCC cells. The mRNA and protein levels of LIMK1 were measured using quantitative RT-PCR and western blotting. Luciferase assays were performed to validate LIMK1 as an miR-106a target in OSCC cells. Results We found that the level of miR-106a significantly decreased and the expression of LIMK1 significantly increased in OSCC tissues and cell lines. There was a close association between these changes. Knockdown of LIMK1 significantly inhibited the proliferation and EMT of OSCC cells. The bioinformatics analysis predicted that LIMK1 is a potential target gene of miR-106a and the luciferase reporter assay confirmed that miR-106a could directly target LIMK1. Introduction of miR-106a to OSCC cells had similar effects to LIMK1 silencing. Overexpression of LIMK1 in OSCC cells partially reversed the inhibitory effects of the miR-106a mimic. Conclusion MiR-106a inhibited the cell proliferation and EMT of OSCC cells by directly decreasing LIMK1 expression

Mesoproterozoic high Fe–Ti mafic magmatism in western Shandong, North China Craton: Petrogenesis and implications for the final breakup of the Columbia supercontinent

High Fe–Ti basic rocks (FeOt > 12 wt% and TiO2 > 2 wt%) are rare in the geological record and display a different evolutionary trend (the ‘Fenner’ trend) from the normal ‘Bowen’ trend of SiO2 enrichment. In this paper, we present geochronological, geochemical and Sr–Nd isotopic data for the Fe–Ti-rich gabbros from western Shandong within the Eastern Block of the North China Craton. Zircon U–Pb dating indicates that they were emplaced at ∼1.21 Ga. All high Fe–Ti gabbros are characterized by low MgO (12 wt%), TiO2 (>2 wt%) and P2O5 (mostly >0.4 wt%). Geochemically, they can be divided into two different series (the alkaline series for the Yishui gabbros and the sub-alkaline series for the Feixian gabbros). Both series of Fe–Ti-rich gabbros show similar depletion in Th, U, Nb and Ta, and have positive Eu anomalies. The main difference is that the alkaline series displays slightly more fractionated REE patterns and more depleted Sr–Nd isotopic compositions than the sub-alkaline series; it also lacks positive P anomalies. Elemental geochemistry indicates that both series were likely generated by the partial melting of lherzolitic mantle, with different proportions of garnet in their sources. The mantle sources were re-enriched through varying degrees of hybridization of lower crustal materials prior to partial melting.The results of modeling based on the Sr–Nd isotopic compositions show that their mantle sources could have formed from the hybridization of N-MORB-like depleted mantle through involvement of around 1% lower crustal components for the alkaline series and 2% for the sub-alkaline series: this accounts for their geochemical signatures, especially for the marked depletion in Th and U, and weak negative Nb and Ta anomalies. A combination of Fe-rich mantle source and subsequent fractional crystallization, coupled with low fO2 during magmatic evolution, likely resulted in the Fe–Ti enrichment trend in both series of gabbros. In combination with regional and global studies, their generation could be related to a prolonged superplume that led to the final breakup of the Columbia supercontinent during Mesoproterozoi