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Breast cancer is a serious threat to human health. The transforming growth factor-β signaling pathway is an important pathway involved in the occurrence and development of cancer. The SMAD family genes are responsible for the TGF-β signaling pathway. However, the mechanism by which genes of the SMAD family are involved in breast cancer is still unclear. Therefore, it is necessary to investigate the biological roles of the SMAD family genes in breast cancer. We downloaded the gene expression data, gene mutation data, and clinical pathological data of breast cancer patients from the UCSC Xena database. We used the Wilcox test to estimate the expression of genes of the SMAD family in cancers. And the biological functions of SMAD family genes using the DAVID website. The Pearson correlation method was used to explore the immune cell infiltration and drug response of SMAD family genes. We conducted in biological experiments vitro and vivo. In this study, we integrated the multi-omics data from TCGA breast cancer patients for analysis. The expression of genes of SMAD family was significantly dysregulated in patients with breast cancer. Except for SMAD6, the expression of other SMAD family genes was positively correlated. We also found that genes of the SMAD family were significantly enriched in the TGF-β signaling pathway, Hippo signaling pathway, cell cycle, and cancer-related pathways. In addition, SMAD3, SMAD6, and SMAD7 were lowly expressed in stage II breast cancer, while SMAD4 and SMAD2 were lowly expressed in stage III cancer. Furthermore, the expression of genes of the SMAD family was significantly correlated with immune cell infiltration scores. Constructing a xenograft tumor mouse model, we found that SMAD3 knockdown significantly inhibited tumorigenesis. Finally, we analyzed the association between these genes and the IC50 value of drugs. Interestingly, patients with high expression of SMAD3 exhibited significant resistance to dasatinib and staurosporine, while high sensitivity to tamoxifen and auranofin. In addition, SMAD3 knockdown promoted the apoptosis of BT-549 cells and decreased cell activity, and BAY-1161909 and XK-469 increased drug efficacy. In conclusion, genes of the SMAD family play a crucial role in the development of breast cancer. [ABSTRACT FROM AUTHOR]

In this work, a series of epoxy-terminated butadiene acrylonitrile copolymer (ETBN) liquid rubber-intercalated organic montmorillonite (OMMT)-filled epoxy nanocomposites were prepared. The dispersion of OMMT was studied by X-ray diffraction analysis and transmission electron microscope analysis. The mechanical strength and damping properties of the resultant nanocomposites were characterized by mechanical tests and dynamic mechanical analysis, respectively. Thermal stabilities of the pure and modified epoxy samples were studied by thermogravimetric analysis. Results revealed that the addition of OMMT and ETBN could improve the damping properties greatly and decrease the glass transition temperature (Tg) of the composites while the high tensile strength of composites was still maintained. Besides, with the addition of the second nano-filler (nano-CaCO3 or nano-SiO2) into the nanocomposites, the tensile strength of the nanocomposites was further enhanced without decreasing the high damping properties. [ABSTRACT FROM AUTHOR]