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Objective To investigate the expression and function of lncRNA XIST in MCF-7 breast cancer cells. Methods The expression of XIST in MCF 10A human normal breast epithelial cells and MCF-7 human breast cancer cells were detected by qRT-PCR. Transient transfection technique was used to overexpress XIST in MCF-7 cells. MTT assay and Transwell assay were used to detect the changes of proliferation, migration and invasion of MCF-7 cells after XIST overexpression in MCF-7 cells. Bioinformatics and qRT-PCR were used to predict and detect the changes of miRNA expression which have potential binding sites of XIST. qRT-PCR was used to detect the expression of XIST in MCF-7 cells which was transfected instantaneously by miR-130b-3p inhibitor. Results XIST expression was decreased in MCF-7 cells, while miR-130b-3p expression was increased, compared with those in MCF-10A cells (both P < 0.001). Overexpression of XIST significantly inhibited the proliferation of MCF-7 cells (P < 0.001), promoted cell migration and invasion. And the expression level of miR-130b-3p in MCF-7 cells was reduced significantly after overexpression of XIST (P < 0.01), while the expression level of XIST in MCF-7 cells was increased significantly after down-expression of miR-130b-3p (P < 0.001). Conclusion The expression levels of XIST and miR-130b-3p in breast cancer MCF-7 cells are negatively correlated, and the overexpression of XIST could significantly inhibit the proliferation, and promote the migration and invasion of MCF-7 cells.

Abstract Background As one of the malignant tumors most often affecting children and young adults, Ewing sarcoma (ES) is characterized by early metastasis contributing to unfavorable prognosis. However, the molecular mechanisms responsible for ES metastasis remain poorly understood. In this study, we aimed to explore whether Wnt5a, a putative pro-metastatic factor, plays a role in ES metastasis. Methods Expression of Wnt5a and CXCR4 was determined by real-time PCR or Western blot in 15 ES specimens and 4 ES cell lines, A-673, RD-ES, SK-N-MC and SK-ES-1. Expression of Wnt antagonists, SFRP1, SFRP2 and SFRP5, and some components in noncanonical Wnt pathway (p-JNK, p-cJUN and p-PKC) was also analyzed in this study. Methylation status of SFRP1, SFRP2 and SFRP5 was detected by Methylation-specific PCR (MSP). Wnt5a shRNA and pcDNA3.1 SFRP5 vector were used to abrogate Wnt5a expression and overexpress SFRP5 in ES cells, respectively. Results Wnt5a expression was positively correlated with CXCR4 expression in ES specimens. Levels of both Wnt5a mRNA and CXCR4 mRNA were significantly higher in specimens from ES patients with metastasis at diagnosis compared with specimens from those without metastasis. Recombinant Wnt5a enhanced CXCR4 expression in ES cells, which was accompanied by increased ES cell migration, whereas Wnt5a shRNA has opposite effects. SFRP5 was methylated and silenced in ES cells, and both recombinant SFRP5 and pcDNA3.1 SFRP5 vector suppressed CXCR4 expression as well as ES cell migration. Wnt5a shRNA and recombinant SFRP5 inhibited phosphorylation of JNK and cJUN, and JNK inhibitor also reduced CXCR4 expression and cell migration in ES cells. Conclusions Wnt5a increases ES cell migration via upregulating CXCR4 expression in the absence of Wnt antagonist SFRP5, suggesting that Wnt5a overexpression and SFRP5 deficiency may jointly promote ES metastasis.

Background: Osteogenesis imperfecta (OI), a rare autosomal inheritable disorder characterized by bone fragility and skeletal deformity, is caused by pathogenic variants in genes impairing the synthesis and processing of extracellular matrix protein collagen type I. With the use of next‐generation sequencing and panels approaches, an increasing number of OI patients can be confirmed and new pathogenic variants can be discovered. This study sought to identify pathogenic gene variants in a Chinese family with OI I. Methods: Whole‐exome sequencing was used to identify pathogenic variants in the proband, which is confirmed by Sanger sequencing and cosegregation analysis; MES, HSF, and Spliceman were used to analyze this splicing variant；qRT‐PCR was performed to identify the mRNA expression level of COL1A1 in patient peripheral blood samples; Minigene splicing assay was performed to mimic the splicing process of COL1A1 variants in vitro; Analysis of evolutionary conservation of amino acid residues and structure prediction of the mutant protein. Results: A novel splicing pathogenic variant (c.3814+1G>T) was identified in this OI family by using whole‐exome sequencing, Sanger sequencing, and cosegregation analysis. Sequencing of RT‐PCR products from the COL1A1 minigene variant reveals a 132‐nucleotide (nt) insertion exists at the junction between exons 48 and exon 49 of the COL1A1 cDNA. Splicing assay indicates that the mutated minigene produces an alternatively spliced transcript which may cause a frameshift resulting in early termination of protein expression. The molecular analysis suggested that the altered amino acid is located at the C‐terminus of type I procollagen. Conclusion: Our study reveals the pathogenesis of a novel COL1A1 splicing pathogenic variant c.3814+1G>T in a Chinese family with OI I. [ABSTRACT FROM AUTHOR]