Project description:We previously showed that overexpression of the miR-200c/141 cluster in the TNBC cell line MDA-MB-231 significantly reduced proliferation and invasion in vitro and tumor growth and metastasis in vivo. To confirm the effects of miR-200s in another TNBC cell line, MDA-MB-436 cells were created to overexpress both the miR-200c/141 cluster and the miR-200b/200a/429 cluster.
Project description:We have previously shown that transgenic overexpression of the miR-200b/200a/429 cluster prevents mammary tumor development in MTB-IGFIR mice. In this study we evaluated whether the miR-200b/200a/429 cluster could also prevent mammary tumor development from a different oncogene, namely Neu/Erbb2. We found that transgenic overexpression of Neu/Erbb2 in MTB-TAN mice induce rapid mammary tumor development and co-overexpression of the miR-200b/200a/429 cluster with Neu/Erbb2 completely prevent mammary epithelial transformation and tumor development
Project description:The miR-200 family of microRNAs consisting of miR-141, miR-200a, miR-200b, miR-200c and miR-429 are key regulators of breast cancer progression. The miR200 family maintains mammary epithelial identity and downregulation of miR-200 expression drives the epithelial-to-mesenchymal transition. Re-expression of one or more miR-200 family members in tumor cells with mesenchymal characteristics may restore the epithelial phenotype and alter growth and metastatic potential. To test this, the miR-200b/200a/429 cluster was re-expressed in a murine claudin-low mammary tumor cell line, RJ423
Project description:miRNAs are an class of small noncoding RNAs and about 21-25 nucleotides in length. miRNAs inhibit the translation or induce mRNA degradation by binding to the 3’ UTR of target mRNAs and have been identified as the tumor promoters or suppressors regulating the progression of cancers. miR-429, which is a member of an evolutionarily conserved family of miRNAs that includes miR-200b, miR-200a, miR-200c and miR-141, is expressed in various epithelial tissues. Our goal is to search the possible target genes of miR-429 in human liver cancer cell line HCCLM3. We analyzed possible target genes of miR-429 by identifying the shared genes among the down-regulated genes in epithelial cell adhesion molecule (EpCAM) negative HCCLM3 cells which treated with miR-429 mimics and the up-regulated genes in EpCAM positive HCCLM3 cells which treated with Antagomir-429.
Project description:The miR-200 family consists of five members expressed as two clusters: miR-200c/141 cluster and miR-200b/200a/429 cluster. In the mammary gland, miR-200s maintain epithelial identity by decreasing the expression of mesenchymal markers leading to high expression of epithelial markers. While the loss of miR-200s is associated with breast cancer growth and metastasis the impact of miR-200 expression on mammary tumor initiation has not been investigated. Using mammary specific expression of the miR-200b/200a/429 cluster in transgenic mice, we found that elevated expression miR-200s could almost completely prevent mammary tumor development. Only 1 of 16 MTB-IGFIRba429 transgenic mice (expressing both the IGF-IR and miR-200b/200a/429 transgenes) developed a mammary tumor while 100% of MTB-IGFIR transgenic mice (expressing only the IGF-IR transgene) developed mammary tumors. RNA sequencing, qRT-PCR, and immunohistochemistry of mammary tissue from 55-day old mice found Spp1, Saa1, and Saa2 to be elevated in mammary tumors and inhibited by miR-200b/200a/429 overexpression. This study suggests that miR-200s could be used as a preventative strategy to protect women from developing breast cancer. One concern with this approach is the potential negative impact miR-200 overexpression may have on mammary function. However, transgenic overexpression of miR-200s, on their own, did not significantly impact mammary ductal development indicating the miR-200 overexpression should not significantly impact mammary function. Thus, this study provides the initial foundation for using miR-200s for breast cancer prevention and additional studies should be performed to identify strategies for increasing mammary miR-200 expression and determine whether miR-200s can prevent mammary tumor initiation by other genetic alterations.
Project description:Three metastatic melanoma cell lines (BD-0548-ME, DP-0574-ME and WP-0614-ME) were transfected with miR precursors: hsa-miR negative control (NC) or hsa-miR-200a-3p precursors (miR-200a). The objective of this experiment was to determine miR-200a targets in metastatic melanoma cell lines. We selected low -miR-200a expression cell lines and then we overexpressed miR-200a or NC. Finally, we compared the metastatic melanoma cell lines with miR-200a overexpression (miR-200a) to the same cell line transfected with the negative control miR (NC).
Project description:For androgen-independent prostate cancer (AIPC), the current treatment is limited and the prognosis is poor. We previously found miR-200b could inhibit androgen independent proliferation ability of prostate cancer cells, but the mechanism is unclear. MiRNAs plays their role by blocking translation through base-pairing with complementary mRNA and by promoting degradation of target mRNA. Unraveling the miRNA translational silencing network remains a challenge in part because a single miRNA can inhibit multiple mRNA targets and because a single mRNA can be regulated by several distinct miRNAs that act cooperatively. However, proteomics methods provide us useful tools to unravel the target genes network. This study identified the target genes of miR-200b in AIPC. It helps us to understand the mechanism of AIPC and applies several new candidate targets of AIPC treatment.