Project description:Whole transcriptome Identification of direct targets of miR-139-5p using biotinylated pull-downs found that this miRNA has roles in breast cancer invasion and migration.
Project description:We performed affymetrix gene expression profiling on mammary tumors from eight well-characterized genetically engineered Mouse (GEM) models of human breast cancer. The gene expression data will be combined with the miRNA gene expression data from the corresponding mammary tumors and tissues for integrated miRNA and mRNA gene expression analysis, which are useful in improving the identification of miRNA targets from potential targets identified in silico.
Project description:Whole transcriptome Identification of direct targets of miR-139-5p using biotinylated pull-downs found that this miRNA has roles in breast cancer invasion and migration. MCF7 cells were transfected with biotinylated miR-139-5p. The miRNAs and target mRNA were pulled down with streptavidin and compared to the input control.
Project description:We performed affymetrix gene expression profiling on mammary tumors from eight well-characterized genetically engineered Mouse (GEM) models of human breast cancer. The gene expression data will be combined with the miRNA gene expression data from the corresponding mammary tumors and tissues for integrated miRNA and mRNA gene expression analysis, which are useful in improving the identification of miRNA targets from potential targets identified in silico. mRNA expression data for 41 mouse primary mammary tumors and 5 mouse normal mammary glands
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:Little is understood about the early molecular drivers of triple-negative breast cancer (TNBC), making the identification of women at risk and development of targeted therapy for prevention significant challenges. By sequencing a TNBC cell line-based breast cancer progression model we have found that miRNA-29c is progressively lost during TNBC tumorigenesis. In support of the tumor suppressive role of miRNA 29c, we found that low levels predict poor overall patient survival and, conversely, that ectopic expression of miRNA-29c in preneoplastic cell models inhibits growth. miRNA-29c exerts its growth inhibitory effects through direct binding and regulation of TGFB-induced factor homeobox 2 (TGIF2), CAMP-responsive element binding protein 5 (CREB5), and V-Akt murine thymoma viral oncogene homolog 3 (AKT3). miRNA-29c regulation of these gene targets seems to be functionally relevant, as TGIF2, CREB5, and AKT3 were able to rescue the inhibition of cell proliferation and colony formation caused by ectopic expression of miRNA-29c in preneoplastic cells. AKT3 is an oncogene of known relevance in breast cancer, and as a proof of principle we found that inhibition of phosphoinositide 3-kinase (PI3K) activity, a protein upstream of AKT3, suppressed proliferation in TNBC preneoplastic cells. We explored additional opportunities for prevention of TNBC by studying the regulation of miRNA-29c and identified DNA methylation to have a role in the inhibition of miRNA-29c during TNBC tumorigenesis. Consistent with these observations, we found 5 aza-cytadine to relieve the suppression of miRNA-29c. Together, these results demonstrate that miRNA-29c loss plays a key role in the early development of TNBC.
Project description:Deficiencies in the ATM gene are the underlying cause for ataxia telangiectasia, a congenital syndrome characterized by neurological, motor and immunological defects, as well as a predisposition to cancer risks. MicroRNAs (miRNAs) are small regulators of post-transcriptional gene expression and a useful tool for cancer diagnosis, staging, and prediction of therapeutic responses to clinical regimens. In particular, miRNAs have been used to develop signatures for breast cancer profiling. We are interested in the consequences of ATM deficiency on miRNA expression in breast epithelial cells and the potential contribution to cancer predisposition. In this study we investigate the effects of ATM loss on the miRNA expression and related gene expression changes in normal human mammary epithelial cells (HME-CC). We have identified 81 significantly differently expressed miRNAs in the ATM-deficient HME-CCs using small RNA sequencing. Many of these differentially expressed miRNAs have been described and implicated in tumorigenesis and proliferation. These changes include down-regulation of tumor suppressor miRNAs, such as hsa-miR-29c and hsa-miR-16, as well as the over-expression of pro-oncogenic miRNAs hsa-miR-93 and hsa-mir-221. All 81 miRNAs were combined with genome wide gene expression profiles to investigate possible targets of miRNA regulation. We identified messenger RNA (mRNA) targets of these miRNAs that were also significantly regulated after the depletion of ATM. Predicted targets included many genes implicated in cancer formation and progression, including SOCS1 and the proto-oncogene MAF. Integrated analysis of miRNA and mRNA expression allows us to build a more complete understanding of the pathways and networks involved in the breast cancer predisposition observed in individuals deficient in ATM. This study highlights miRNA and predicted mRNA target expression changes in ATM-deficient HME-CCs and suggests a mechanism for the breast cancer-prone phenotype seen in ATM deficient cells and patients. Additionally, this study provides preliminary data for defining miRNA profiles that may be used prognostic biomarkers for breast cancer predisposition.