Project description:We analyzed the miRNA expression in 6 breast cancer cell lines from young (HCC1500, HCC1937) and old (MCF-7, MDA-MB-231, HCC1806 and MDA-MB-468) patients with breast cancer using the GeneChip® miRNA 2.0 Array (Affymetrix, Santa Clara, CA, USA).
Project description:The project aimed to identify miRNA that varied with tumourigenicity in human breast cell lines. The second objective was to identify miRNA that had differential expression between cell lines that varied in accordance with the abundance of the tetraspanin CD9 in the cell lines and the degree to which endogenous factors within these cell lines interacted with the 3'UTR of CD9 as determined by dual luciferase assay. These miRNA were considered potential regulators of the abundance of CD9 in breast cancer.
Project description:MicroRNA (miRNA/miR) miR526b and miR655 overexpressed tumor cell-free secretions promote breast cancer phenotypes in the tumor microenvironment (TME). However, the mechanisms of miRNA regulating TME have never been investigated. With mass spectrometry analysis of MCF7-miRNA-overexpressed versus miRNA-low MCF7-Mock tumor cell secretomes, we identified 34 novel secretory proteins coded by eight genes YWHAB, TXNDC12, MYL6B, SFN, FN1, PSMB6, PRDX4, and PEA15 those are differentially regulated. We used bioinformatic tools and systems biology approaches to identify these markers’ role in breast cancer. Gene ontology analysis showed that the top functions are related to apoptosis, oxidative stress, membrane transport, and motility, supporting miRNA-induced phenotypes. These secretory markers expression is high in breast tumors, and a strong positive correlation exists between upregulated markers’ mRNA expressions with miRNA cluster expression in luminal A breast tumors. Gene expression of secretome markers is higher in tumor tissues compared to normal samples, and immunohistochemistry data supported gene expression data. Moreover, both up and downregulated marker expressions are associated with breast cancer patient survival. miRNA regulates these marker protein expressions by targeting transcription factors of these genes. Premature miRNA (pri-miR526b and pri-miR655) are established breast cancer blood biomarkers. Here we report novel secretory markers upregulated by miR526b and miR655 (YWHAB, MYL6B, PSMB6, and PEA15) are significantly upregulated in breast cancer patients’ plasma, and are potential breast cancer biomarkers.
Project description:miRNA expression is often disregulated in cancer pathways, such as progression of resistance. We used microarrays in order to determine the differences in miRNA expression between breast cancer cell lines and their resistant pairs.
Project description:Bone morphogenetic protein 4 (BMP4) is a remarkably powerful inhibitor of breast cancer cell proliferation, but is also able to induce breast cancer cell migration in certain cellular contexts. Previous data demonstrate that BMP4 controls the transcription of a variety of protein coding genes, but not much is known about microRNAs (miRNA) regulated by BMP4. In this study, miRNA expression patterns following BMP4 treatment were determined in one mammary epithelial and seven breast cancer cell lines using microarrays. The analysis identified 20 to 128 differentially expressed miRNAs in individual cell lines with emphasis on upregulation over downregulation. Four miRNAs (miR-16-5p, miR-106b-5p, miR-23a-3p and miR-23b-3p) were commonly induced in a subset of breast cancer cells upon BMP4 treatment and inhibition of their expression resulted in an increase in BT-474 cell number, indicating that they possess tumor suppressive properties. Yet no major change was detected when the cells were simultaneously treated with BMP4, and thus these miRNAs do not act as the main mediators of BMP4-induced growth reduction. MiR-16-5p and miR-106b-5p were elevated in MDA-MB-231 cells that respond to BMP4 with increased migration. Their inhibition, in combination with BMP4 treatment, resulted in enhanced MDA-MB-231 cell migration, suggesting that miR-16-5p and miR-106b-5p are engaged in BMP4-induced motility. Taken together, we have shown for the first time that in breast cancer cells BMP4 induces variable miRNA expression patterns.