Effects of Benzo (a) Pyrene and 2,2',4,4'-Tetrabromodiphenyl Ether Exposure on the Thyroid Gland in Rats by Attenuated Total Reflection Fourier-Transform Infrared Spectroscopy.

Benzo[a]pyrene (B[a]P) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) are widespread environmental pollutants and can destroy thyroid function. We assessed the biochemical changes in the thyroid tissue of rats exposed to B[a]P and BDE-47 using attenuated total reflection Fourier-transform infrared spectroscopy combined with support vector machine(SVM). After B[a]P and BDE-47 treatment in rats, the structure of thyroid follicles was destroyed and epithelial cells were necrotic, indicating that B[a]P and BDE-47 may lead to changes of the thyroid morphology of the rats. These damages are mainly related to C=O stretch vibrations of lipids (1743 cm-1), as well as the secondary structure of proteins [amide I (1645 cm-1) and amide II (1550 cm-1)], and carbohydrates [C-OH (1138 cm-1), C-O (1106 cm-1, 1049 cm-1, 991 cm-1), C-C (1106 cm-1) stretching] and collagen (phosphodiester stretching at 922 cm-1) vibration modes. When SVM was used for classification, there was a substantial separation between the control and the exposure groups (accuracy = 96%; sensitivity = 98%; specificity = 87%), and there was also a major separation between the exposed groups (accuracy = 93%; sensitivity = 94%; and specificity = 92%).

Whole transcriptome sequencing and competitive endogenous RNA regulation network construction analysis in benzo[a]pyrene-treated breast cancer cells.

Breast cancer is the most common malignant tumor in women worldwide, and environmental pollutants are considered to be risk factors. Currently, most studies into benzo[a]pyrene (B[a]P)-induced breast cancer focus on biological effects such as proliferation, invasion, and metastasis, DNA damage, estrogen receptor (ER)-related molecular mechanisms, oxidative damage, and other metabolic pathways. This study aims to provide insights into the role of B[a]P in breast cancer development through RNA-seq and bioinformatics analysis and construction of a competing endogenous RNA (ceRNA) regulatory network. By analyzing RNA-seq results, we identified 144 differentially-expressed circRNAs, 69 differentially-expressed lncRNAs, 20 differentially-expressed miRNAs, and 212 differentially-expressed mRNAs. Following on, we analyzed the gene ontology (GO) and KEGG enrichment functions of the differentially-expressed RNAs. In addition, the protein-protein interaction (PPI) network was mapped for differentially-expressed mRNAs. Subsequently, we constructed ceRNA networks, one of which consisted of 45 dysregulated circRNAs, 11 miRNAs, and 9 mRNAs, and a second consisted of 40 lncRNAs, 11 miRNAs, and 9 mRNAs. Finally, 6 circRNAs, 4 lncRNAs, 1 miRNA, and 4 mRNAs were randomly selected for quantitative real-time PCR verification. PCR results were further verified by Western blotting assays. These results show that the expression level of differentially-expressed RNA was consistent with the sequencing data, and the Western blotting results were highly consistent with the PCR results, confirming that the sequencing result was very reliable. This study systematically explores the ceRNA atlas of differentially-expressed genes related to B[a]P exposure in breast cancer cells, providing new insights into mechanisms of environmental pollutants in breast cancer.

Deciphering the Oncogenic Role of VPS28 Modulated by miR-491-5p in Breast Cancer Cells Using In Silico and Functional Analysis.

Vacuolar protein sorting-associated protein 28 (VPS28), one of the four cytosolic proteins comprising the endosomal sorting complex required for the transport I (ESCRT-I) component, has been reported to be linked to various cancers. However, less evidence is available regarding the involvement of VPS28 in breast cancer. To this end, this study focused on exploring the function of VPS28 in breast cancer cells using the in silico analysis. VPS28 expression pattern data in breast cancer tissues were collected using the Cancer Genome Atlas (TCGA) and Clinical Proteomic Tumor Analysis Consortium (CPTAC) databases and analyzed to assess the association of VPS28 with breast cancer prognosis. The elevated VPS28 expression was found in breast cancer tissues and was associated with a poor prognosis (p < 0.001). A higher VPS28 expression indicated a short survival duration (HR = 2.43; 95% CI: 1.44-4.1; p < 0.001). The CCLE database showed that VPS28 was expressed in breast cancer cell lines. The upstream targets of VPS28 were identified using the mirDIP, starBase, and TargetScan online tools. The correlation and binding relationship between miR-491-5p and VPS28 was analyzed. VPS28 or miR-491-5p gain and loss of function experiments were performed to verify their potential effect on the biological functions of breast cancer cells. Knockdown of VPS28 was shown to suppress the biological functions and enhance the apoptosis of breast cancer cell lines. Micro RNA-491-5p, identified as a posttranscriptional regulator of VPS28, was downregulated in breast cancer tissues. In contrast to the miR-491-5p inhibitor, the miR-491-5p mimic could suppress the migration, wound healing ability, and proliferation, while accelerating apoptosis. However, co-transfection of VPS28 and miR-491-5p counteracted the effect of the miR-491-5p mimic on breast cancer cell functions. Thus, our in silico analysis demonstrates that miR-491-5p can suppress breast cancer progression by attenuating the expression of VPS28.

Global, regional, and national mortality trends of female breast cancer by risk factor, 1990-2017.

BACKGROUND: Female breast cancer (FBC) is a malignancy involving multiple risk factors and has imposed heavy disease burden on women. We aim to analyze the secular trends of mortality rate of FBC according to its major risk factors. METHODS: Death data of FBC at the global, regional, and national levels were retrieved from the online database of Global Burden of Disease study 2017. Deaths of FBC attributable to alcohol use, high body-mass index (BMI), high fasting plasma glucose (FPG), low physical activity, and tobacco were collected. Estimated average percentage change (EAPC) was used to quantify the temporal trends of age-standardized mortality rate (ASMR) of FBC in 1990-2017. RESULTS: Worldwide, the number of deaths from FBC increased from 344.9 thousand in 1990 to 600.7 thousand in 2017. The ASMR of FBC decreased by 0.59% (95% CI, 0.52, 0.66%) per year during the study period. This decrease was largely driven by the reduction in alcohol use- and tobacco-related FBC, of which the ASMR was decreased by 1.73 and 1.77% per year, respectively. In contrast, the ASMR of FBC attributable to high BMI and high FPG was increased by 1.26% (95% CI, 1.22, 1.30%) and 0.26% (95% CI, 0.23, 0.30%) per year between 1990 and 2017, respectively. CONCLUSIONS: The mortality rate of FBC experienced a reduction over the last three decades, which was partly owing to the effective control for alcohol and tobacco use. However, more potent and tailored prevention strategies for obesity and diabetes are urgently warranted.