Project description:Metastatic disease is a primary cause of cancer-related death, and factors governing tumor cell metastasis have not been fully elucidated. Here we addressed this question by using tumor cell lines derived from mice that develop metastatic lung adenocarcinoma owing to expression of mutant K-ras and p53. A feature of metastasis-prone tumor cells that distinguished them from metastasis-incompetent tumor cells was plasticity in response to changes in their microenvironment. They transited reversibly between epithelial and mesenchymal states, forming highly polarized epithelial spheres in 3-dimensional culture that underwent epithelial-mesenchymal transition (EMT) following treatment with transforming growth factor-beta or injection into syngeneic mice. This plasticity was entirely dependent upon the microRNA-200 family, which decreased during EMT. Forced expression of miR-200 abrogated the capacity of these tumor cells to undergo EMT, invade, and metastasize and conferred transcriptional features of metastasis-incompetent tumor cells. We conclude that microenvironmental cues direct tumor metastasis by regulating miR-200 expression.
Project description:This SuperSeries is composed of the following subset Series:; GSE14449: Gene expression profiles of spontaneous metastasis in a K-ras/p53 mutant mouse model; GSE14458: Gene expression profiles of 344SQ lung adenocarcinoma cells with high metastatic potential (syngeneic mouse model) Experiment Overall Design: Refer to individual Series
Project description:Metastatic disease is a primary cause of cancer-related death, and factors governing tumor cell metastasis have not been fully elucidated. Here we addressed this question by using tumor cell lines derived from mice that develop metastatic lung adenocarcinoma owing to expression of mutant K-ras and p53. A feature of metastasis-prone tumor cells that distinguished them from metastasis-incompetent tumor cells was plasticity in response to changes in their microenvironment. They transited reversibly between epithelial and mesenchymal states, forming highly polarized epithelial spheres in 3-dimensional culture that underwent epithelial-mesenchymal transition (EMT) following treatment with transforming growth factor-beta or injection into syngeneic mice. This plasticity was entirely dependent upon the microRNA-200 family, which decreased during EMT. Forced expression of miR-200 abrogated the capacity of these tumor cells to undergo EMT, invade, and metastasize and conferred transcriptional features of metastasis-incompetent tumor cells. We conclude that microenvironmental cues direct tumor metastasis by regulating miR-200 expression. Experiment Overall Design: Cell lines from p53R172Hâ??g/+ K-rasLA1/+ mice were derived from tumor tissues removed at autopsy from two different mice (#344 and #393). The tissues were minced, placed in culture, and passed serially in RPMI 1640 supplemented with 10% fetal bovine serum (FBS), which yielded mass populations of tumor cells derived from primary lung tumors (344P and 393P), mediastinal lymph nodes (344LN and 393LN), and a subcutaneous site (344SQ). Stable 344SQ cell lines expressing the miR-200b-200a-429 cluster or control vector were generated by transduction with lentivirus vectors. GFP positive transfectant pools were selected by growth in RPMI 1640 with 10% FBS and puromycin. RNA samples of miR-200b-200a-429 knockup versus control (from triplicate cultures of each) were processed and analyzed on Affymetrix Mouse Expression Array 430A 2.0 chips.
Project description:Here, we elucidated whether miR-200 family members control RNA-binding protein quaking (QKI), a newly identified tumor suppressor that is regulated during EMT. QKI expression was suppressed by miR-200 overexpression, and the 3'-UTR of QKI mRNA was directly targeted by miR-200 in luciferase reporter assays. ShRNA-mediated knockdown of QKI led to pronounced EMT and protumor effects in both in vitro and in vivo studies of oral squamous cell carcinoma. Furthermore, high expression of QKI protein is associated with favorable prognosis in surgically resected head and neck squamous cell carcinoma and lung adenocarcinoma. In conclusion, QKI increases during EMT and is targeted by miR-200; while, it suppresses EMT and tumorigenesis. We suggest that QKI and miR-200 form a negative feedback loop to maintain homeostatic responses to EMT-inducing signals.
Project description:Claudin-low tumors are a highly aggressive breast cancer subtype with no targeted treatments and a clinically documented resistance to chemotherapy. They are significantly enriched in cancer stem cells (CSCs), which makes claudin-low tumor models particularly attractive for studying CSC behavior and developing novel approaches to minimize CSC therapy resistance. One proposed mechanism by which CSCs arise is via an epithelial-mesenchymal transition (EMT), and reversal of this process may provide a potential therapeutic approach for increasing tumor chemosensitivity. Therefore, we investigated the role of the miR-200 family of microRNAs in regulating the epithelial state, stem-like properties, and therapeutic response in an in vivo primary, syngeneic p53null claudin-low tumor model that is normally deficient in miR-200 expression. Using an inducible lentiviral approach, we expressed the miR-200c cluster in this claudin-low model and found that it changed the epithelial state, and consequently, impeded CSC behavior in these mesenchymal tumors. Moreover, these state changes were accompanied by a decrease in proliferation and an increase in the differentiation status. MiR-200c expression also forced a significant reorganization of tumor architecture, affecting important cellular processes involved in cell-cell contact, cell adhesion, and motility. Accordingly, induced miR200c expression also significantly enhanced the chemosensitivity and decreased the metastatic potential of this p53null claudin-low tumor model. Collectively, our data suggest that miR-200c expression in claudin-low tumors offers a potential therapeutic application to disrupt the EMT program on multiple fronts in this mesenchymal tumor subtype, by altering tumor growth, chemosensitivity, and metastatic potential in vivo. reference x sample
Project description:MicroRNAs are critical regulators of gene networks in normal and abnormal biological processes. Focusing on invasive ductal breast cancer (IDC), we have found dysregulated expression in tumor samples of several microRNAs, including the miR-200 family, along progression from primary tumors to distant metastases, further reflected in higher blood levels of miR-200b and miR-7 in IDC patients with regional or distant metastases relative to patients with primary node-negative tumors. Forced expression of miR-200s in MCF10CA1h mammary cells induced an enhanced epithelial program, aldehyde dehydrogenase (ALDH) activity, mammosphere growth and ability to form branched tubuloalveolar structures while promoting orthotopic tumor growth and lung colonization in vivo. Knockdown of the miR-200 target, ZEB2, partially phenocopied the expression of miR200s with a strong enhancement of mammosphere growth and ALDH activity. Interestingly, the morphology of tumors formed in vivo by cells expressing miR-200s was reminiscent of metaplastic breast cancer (MBC). Indeed, the epithelial components of MBC samples expressed significantly higher levels of miR-200s than their mesenchymal components and displayed a marker profile compatible with luminal progenitor cells. We propose that microRNAs of the miR-200 family promote traits of highly proliferative breast luminal progenitor cells, thereby exacerbating the growth and metastatic properties of transformed mammary epithelial cells.
Project description:Background: MicroRNAs are noncoding RNA molecules of ~22 nucleotides with diagnostic and therapeutic action, affecting the expression of mRNAs involved in invasion, migration, and development. miR-200c is part of the miR-200c/141 cluster on chromosome 12p13. Its mechanism of action when encapsulated is critical in lung cancer when patients express changes in miRNAs. miR-200c be a potential biomarkers for various lung diseases. As a potential therapy, miR-200c can impact lives as target lung cancer is a leading cause of death with about 234,000 cases annually, high heterogeneity, complex screening, and a 5-year survival rate of 16%. Encapsulated miR-200c efficiently enhances bioavailability, pharmacokinetics of therapeutics and targeting to cells, improves efficacy and provides potential cure. Methods: The functions of miR-200c were determined in non-metastatic KW-634 and metastatic 821-T4 and 821-LN mouse lung cancer cell lines after various nano vehicle treatments. Viability and cytotoxicity were determined by cell cycle and quantitative real-time PCR analyses were used to quantify levels of miR-200c and its target genes. In situ hybridization was used to visualize patterns of expression of miR-200c and others in the lung and many organs. Next-generation sequencing, invasion and migration assays using transwell chambers, and ActivSignal were used to elucidate the activation and inhibition profiles and perform direct expression measurements and modification of cellular components.
Project description:Long noncoding RNAs (lncRNAs) are a class of transcripts longer than 200 nucleotides with limited protein coding potential. Long non-coding RNAs (lncRNAs) play an important role in lung adenocarcinoma (LUAD) metastasis. In this study, we profiled matched tissue from LUAD patients with HTA 2.0 microarray analysis and identified lncRNA- chromatin-associated RNA 10 (CAR10) as obviously clearly overexpressed in LUAD tissues. we demonstrated that CAR10 accelerates tumor growth and promotes metastasis in lung adenocarcinoma. CAR10 was shown to promote epithelial-to-mesenchymal transition (EMT) translation of LUAD cells through sponging miR-30/203, leading to upregulation of SNAI1/2 expression.
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