Project description:ADAR1 catalyzes Adenosine-to-Inosine (A-to-I) editing of double-stranded RNA and regulates global expression output through its interactions with RNA and other proteins. ADARs play important roles in development and disease, and previous work has shown that ADAR1 is oncogenic in a growing list of cancer types. Here we show that ADAR1 is important for growth and invasion in triple negative breast cancer cells, as ADAR1 loss yields reduced growth, migration & invasion, and mammosphere formation. Global RNA-seq analyses demonstrate that ADAR1 regulates both coding and non-coding targets via expression level and/or A-to-I editing. We demonstrated that a recoding edit in FLNB (chr3:58156064) inhibits the tumor suppressive activities of the protein to promote growth & invasion. We show that several tumor suppressor microRNAs are also downregulated by ADAR1 to promote cell cycle progression and invasion. This work describes several novel mechanisms of ADAR1-mediated oncogenesis in triple negative breast cancer, providing support to strategies for targeting ADAR1 in this aggressive cancer type with few treatment options.
Project description:Targeted interference of sin3a-tgif1 function by SID decoy treatment inhibits WNT signaling and invasion in triple negative breast cancer cells. MDA-MB-231 cells were treated with scrambled SID control, 2.5µM SID peptide or untreated for 24h.
Project description:Aberrant RNA-editing was observed in several human tumors, but its significance is mostly unknown. Here we show that ADAR1, a ubiquitous RNA-editing enzyme, is commonly lost in metastatic melanoma cells and specimens. Experimental ADAR1 silencing significantly alters melanoma cell morphology, facilitates proliferation and cell-cycle, and increases the tumorigenicity in-vivo. A series of ADAR1 truncation mutants establishes a novel RNA-editing-independent role for ADAR1 in controlling the nuclear and cytoplasmic processing steps of miRNA biogenesis. Altered expression of ADAR1-controled miRNAs accounts for the observed phenotype. We show that the oncogenic miR-17-5p endogenously regulates ADAR1 expression and that its genomic sequence is frequently amplified in melanoma to overexpress the mature miR-17-5p form. ADAR1 and miR-17-5p are ubiquitously expressed, suggesting the generality of this mechanism. Melanoma cell line expressing low ADAR1 levels (ADAR1-Knockdown) using shRNA technique were selected for RNA extraction and hybridization on Affymetrix microarrays. We sought to examine the alterations in the genes and microRNA expression profile in the manipulated cell system, due to ADAR1 possible involvement cancer development. To that end, we selected ADAR1-knockdown (ADAR1-KD) cells that demonstrated an enhanced aggressive phenotype both in vivo and in vitro as compared to the control cells (Control).
Project description:Targeted interference of sin3a-tgif1 function by SID decoy treatment inhibits WNT signaling and invasion in triple negative breast cancer cells. MDA-MB-231 cells were treated with scrambled SID control, 2.5µM SID peptide or untreated for 24h. Sub-confluent cultures of MDA-MB-231 cells were treated with scrambled SID control, 2.5µM SID peptide or untreated for 24h. Experiments were performed as three independent replicates.
Project description:Purpose: The BET family protein BRD4 is an important anti-tumor target and is highly expressed in breast cancer. However, BET inhibitors are susceptible to drug resistance. The aim of this study is to explore the mechanism of BET inhibitor JQ-1 combined with cardamonin in the anti-invasion and metastasis of triple-negative breast cancer. Methods: triple-negative breast cancer cells mRNA of DMSO (Control), JQ-1,cardamonin and combined groups were progressed with deep sequencing, in triplicate through Illumina sequencing platform (HiSeqTM 2500). Genes with adjusted P-value < 0.01 and |foldChange| > 2 were defined as differentially expressed genes (DEGs) and subjected to the following GO and KEGG enrichment. qRT-PCR was performed to validate several essential genes using QuantStudio 5 (Thermo Fisher) and SYBR Green assays. Results: As an inhibitor of mTOR, Cardamonin(CAR) can inhibit the proliferation of tumors. Research have found that BET inhibitor can affect the function of a large number of genes by regulating the epigenome, which plays an important role in a variety of diseases. In this study we explored the JQ1 which is a BRD4 protein inhibitor can inhibit the proliferation and metastasis of MDA-MB-231 cells in triple-negative breast cancer cell lines, and this phenomenon can be significantly enhanced when CAR is combined with JQ-1, and the same results are shown in mouse tumor formation experiments and triple-negative breast cancer organoids. At the same time, RNA-seq was performed in MD1-MB-231 cells to explore the changes of specific molecular signaling pathways. We have mapped over 40 million sequence reads to the MDA-MB-231 cell line genome in each specimen.Compared with the control group, CAR and JQ1, the combination group has significantly enriched gene expression. KEGG and GO enrichment analysis indicate that the combination group showed a series of biological processes such as macroautophagy, negative regulation of cell growth, lipid catabolic process, which led to decreased cell viability and decreased proliferation and metastasis ability. Conclusions: In this study, we demonstrated that JQ-1 combined with cardamomin could inhibit the invasion and metastasis of triple-negative breast cancer MDA-MB-231 cells, induce cell cycle arrest and promote cell apoptosis. The results of RNA-Seq were consistent with our in vitro and in vivo experiments, which demonstrated that the combination of JQ-1 and cardamonin effectively inhibited the proliferation, invasion and metastasis of MDA-MB-231 cells.
Project description:The high-throughput sequencing technology was performed after the treatment of human triple negative breast cancer cells MDA-MB-231 with the active compound D16 designed and synthesized by ourselves, to explore the expression of genes related to cell proliferation, adhesion, migration and invasion of human triple negative breast cancer cells MDA-MB-231 after the treatment of the active compound Changes to explore the effect of active compounds on the proliferation and motility of triple breast breast cancer cells and to find an interesting target gene, CKAP2.
Project description:The high-throughput sequencing technology was performed after the treatment of human triple negative breast cancer cells MDA-MB-231 and BT549 with Lespedeza bicolor root extracted by ourselves, to explore the expression of genes related to cell proliferation, adhesion, migration and invasion of human triple negative breast cancer cells MDA-MB-231 and BT549 after the treatment of Lespedeza bicolor root changes, and to find an interesting target gene.
Project description:Efforts to improve the clinical outcome of highly aggressive triple-negative breast cancer (TNBC) have been hindered by the lack of effective targeted therapies. Thus, it is important to identify the specific gene targets/pathways driving the invasive phenotype to develop more effective therapeutics. Here we show that ubiquitin-associated and SH3 domain-containing B (UBASH3B), a protein tyrosine phosphatase, is overexpressed in TNBC, where it supports malignant growth, invasion, and metastasis largely through modulating epidermal growth factor receptor (EGFR). We also show that UBASH3B is a functional target of anti-invasive microRNA200a (miR200a) that is down-regulated in TNBC. Importantly, the oncogenic potential of UBASH3B is dependent on its tyrosine phosphatase activity, which targets CBL ubiquitin ligase for dephosphorylation and inactivation, leading to EGFR up-regulation. Thus, UBASH3B may function as a crucial node in bridging multiple invasion-promoting pathways, thereby providing a potential therapeutic target for TNBC.
Project description:Breast cancer is a heterogeneous disease comprised of four molecular subtypes defined by whether the tumor-originating cells are luminal or basal epithelial cells. Breast cancers arising from the luminal mammary duct often express estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth receptor 2 (HER2). Tumors expressing ER and/or PR are treated with anti-hormonal therapies, while tumors overexpressing HER2 are targeted with monoclonal antibodies. Immunohistochemical detection of ER, PR, and HER2 receptors/proteins is a critical step in breast cancer diagnosis and guided treatment. Breast tumors that do not express these proteins are known as “triple negative breast cancer” (TNBC) and are typically basal-like. TNBCs are the most aggressive subtype, with the highest mortality rates and no targeted therapy, so there is a pressing need to identify important TNBC tumor regulators. The signal transducer and activator of transcription 3 (STAT3) transcription factor has been previously implicated as a constitutively active oncogene in TNBC. However, its direct regulatory gene targets and tumorigenic properties have not been well characterized. By integrating RNA-seq and ChIP-seq data from 2 TNBC tumors and 4 cell lines, we discovered novel gene signatures directly regulated by STAT3 that were enriched for processes involving inflammation, immunity, and invasion in TNBC. Functional analysis revealed that STAT3 has a key role regulating invasion and metastasis, a characteristic often associated with TNBC. Our findings suggest therapies targeting STAT3 may be important for preventing TNBC metastasis.