MicroRNA Expression in Cutaneous Squamous Cell Carcinoma
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ABSTRACT: Cutaneous squamous cell carcinoma (cSCC) is the second most commonly diagnosed cancer in the United States each year. Despite a generally good prognosis, metastatic cSCC results in over 3500 deaths annually. There are no specifically targeted therapies or biomarkers for metastatic cSCC. To determine whether aberrant microRNA expression occurs in metastatic cSCC which could provide novel targets for therapy or biomarkers for earlier diagnosis or prognosis, microRNA expression profiling was performed in 48 samples including normal skin, primary tumors and metastases. Multiple microRNAs showed differential expression; miR-4286, miR-200a-3p and miR-148-3p showed increased expression and miR-1915-3p, miR-205-5p, miR-4516 and miR-150-5p showed reduced expression in metastatic samples. Several microRNAs previously showing aberrant expressionshown to be aberrantly expressed in primary cSCCs were also observed in this study including miR-100, miR-135b, miR-145, miR-21, and miR-214. In summary, several microRNAs show differential expression between primary and metastatic cSCCs; these may be useful as biomarkers for metastasis or as targets for therapytherapeutic targets. RNA extracted from primary human tissues
Project description:Cutaneous squamous cell carcinoma (cSCC) is the second most commonly diagnosed cancer in the United States each year. Despite a generally good prognosis, metastatic cSCC results in over 3500 deaths annually. There are no specifically targeted therapies or biomarkers for metastatic cSCC. To determine whether aberrant microRNA expression occurs in metastatic cSCC which could provide novel targets for therapy or biomarkers for earlier diagnosis or prognosis, microRNA expression profiling was performed in 48 samples including normal skin, primary tumors and metastases. Multiple microRNAs showed differential expression; miR-4286, miR-200a-3p and miR-148-3p showed increased expression and miR-1915-3p, miR-205-5p, miR-4516 and miR-150-5p showed reduced expression in metastatic samples. Several microRNAs previously showing aberrant expressionshown to be aberrantly expressed in primary cSCCs were also observed in this study including miR-100, miR-135b, miR-145, miR-21, and miR-214. In summary, several microRNAs show differential expression between primary and metastatic cSCCs; these may be useful as biomarkers for metastasis or as targets for therapytherapeutic targets.
Project description:A defining feature of the mammalian liver is polyploidy, a numerical change in the entire complement of chromosomes. The first step of polyploidization involves cell division with failed cytokinesis. Although polyploidy is common, affecting ~90% of hepatocytes in mice and 50% in humans, the specialized role played by polyploid cells in liver homeostasis and disease remains poorly understood. The goal of this study was to identify novel signals that regulate polyploidization, and we focused on microRNAs (miRNAs). First, to test whether miRNAs could regulate hepatic polyploidy we examined livers from Dicer1 liver-specific knockout mice, which are devoid of mature miRNAs. Loss of miRNAs resulted in a 3-fold reduction in binucleate hepatocytes, indicating that miRNAs regulate polyploidization. Secondly, we surveyed age-dependent expression of miRNAs in wild-type mice and identified a subset of miRNAs, including miR-122, that is differentially expressed at 2-3 weeks, a period when extensive polyploidization occurs. Next, we examined Mir122 knockout mice and observed profound, life-long depletion of polyploid hepatocytes, proving that miR-122 is required for complete hepatic polyploidization. Moreover, the polyploidy defect in Mir122 knockout mice was ameliorated by adenovirus-mediated over-expression of miR-122, underscoring the critical role miR-122 plays in polyploidization. Finally, we identified direct targets of miR-122 (Cux1, Rhoa, Iqgap1, Mapre1, Nedd4l and Slc25a34) that regulate cytokinesis. Inhibition of each target induced cytokinesis failure and promoted hepatic binucleation. Conclusion: Our data demonstrate that miR-122 is both necessary and sufficient in liver polyploidization. Among the different signals that have been associated with hepatic polyploidy, miR-122 is the first liver-specific signal identified. These studies will serve as the foundation for future work investigating miR-122 in liver maturation, homeostasis and disease. Livers from C57Bl/6 mice were isolated at defined ages: embryonic day 15.5 (n=3; mixed gender), 2 weeks (n=3; male), 3 weeks (n=3, male) and 7 weeks (n=3; male). Differential miRNA expression was assessed using the nCounter Mouse miRNA Expression Assay Kit (nanoString).
Project description:MicroRNA deregulation is frequent in human colorectal cancers (CRCs) but little is known to whether it represents a bystander event or actually drives tumor progression in vivo. We show that miR-135b over-expression is triggered in mouse and humans by APC loss, PTEN/PI3K pathway deregulation and by SRC over-expression and promotes tumor transformation and progression. We show that miR-135b up-regulation is common to sporadic and inflammatory bowel disease-associated human CRCs and correlates with tumor stage and poor clinical outcome. Inhibition of miR-135b in CRC mouse models reduces tumor growth controlling genes involved in proliferation, invasion and apoptosis. We identify miR-135b as a key down-steam effector of oncogenic pathways and a potential novel target for CRC patient’s treatment. RNA was extracted from fresh frozen tissues from tumours from APC;CpC and AOM/DSS mice and normal matched tissues
Project description:In acute myeloid leukemia (AML), leukemia stem cells (LSC) play a central role in disease progression and recurrence due to their intrinsic capacity for self-renewal and chemotherapy resistance. Whereas epigenetic regulation balances normal blood stem cell self-renewal and fate decisions, mutation and dysregulation of epigenetic modifiers are now considered fundamental to leukemia initiation and progression. Alterations in miRNA function represent a non-canonical epigenetic mechanism influencing malignant hematopoiesis, however the function of miRNA in LSC remains undetermined. Here we show that miRNA profiling of fractionated AML populations defines an LSC-specific signature that is highly predictive of patient survival. Gain of function genetic analysis demonstrated that miR-126 restrained cell cycle progression, prevented LSC differentiation, and increased LSC self-renewal. miR-126 promoted chemo-resistance, preserving LSC quiescence in part through suppression of the G0 to G1 gatekeeper, CDK3. Thus, in AML, miRNAs influence patient outcome through post-transcriptional regulation of stemness programs in LSC. 74 primary patient normal karyotype AML samples were analyzed for miRNA expression.
Project description:We found that miR-199a-3p expression is decreased in cSCC biopsies and cell lines compared to normal skin biopsies or normal keratinocytes cell. To understand the role lost expression of miR-199a-3p might have in tumorigenesis of keratinocytes, we aimed to fine possible biochemical pathways and possible targets of miR-199a-3p in cSCC. In order do so, we overexpressed miR-199a-3p in cSCC and used microarrays to find global gene expression affected by miR-199a-3p.
Project description:Global downregulation of microRNAs (miRNAs) is commonly observed in human cancers and can have a causative role in tumorigenesis. The mechanisms responsible for this phenomenon remain poorly understood. Here we show that YAP, the downstream target of the tumor-suppressive Hippo signaling pathway regulates miRNA biogenesis in a cell density-dependent manner. At low cell density, nuclear YAP binds and sequesters p72 (DDX17), a regulatory component of the miRNA processing machinery. At high cell density, Hippo-mediated cytoplasmic retention of YAP facilitates p72 association with Microprocessor and binding to a specific sequence motif in pri-miRNAs. Inactivation of the Hippo pathway or expression of constitutively active YAP causes widespread miRNA suppression in cells and tumors and a corresponding post-transcriptional induction of MYC expression. Thus, the Hippo pathway links contact-inhibition regulation to miRNA biogenesis and may be responsible for the widespread miRNA repression observed in cancer. Two conditions (Low density and High density) were analyzed in duplicate.
Project description:Gene expression data of HER2+ breast tumor samples Increasing evidence indicates that a subset of patients with HER2-positive breast cancer may achieve significant clinical benefit with anti-HER2 targeted therapy without chemotherapy. Thus, identification of biomarkers of long-term benefit from anti-HER2 agents is needed, especially in the metastatic setting. In the HERLAP study (NCT00842998), patients with HER2-positive metastatic breast cancer were randomized to trastuzumab or lapatinib as first-line therapy. Patients showing radiological signs of tumor regression after 8 weeks of treatment were allowed to continue on single agent anti-HER2 therapy until disease progression. Chemotherapy was added to anti-HER-2 therapy in patients failing to achieve tumor regression at the 8-week evaluation and those progressing at any time. Expression analysis of 105 selected genes was performed from formalin-fixed paraffin-embedded in 17 primary tumor samples. The research-based PAM50 intrinsic subtypes were also identified. The association of the expression of each biomarker with clinical outcome endpoints was evaluated. Nineteen patients were enrolled. In 4 patients (21.1%) we observed disease control lasting longer than 12 months with single agent anti-HER2 therapy (range 14.9-38.8 months). High expression of 17q12-21 amplicon genes HER2 and GRB7, and the PAM50 HER2-enriched intrinsic profile, were found significantly associated with 8-week overall response rate and with the duration of disease control during single agent anti-HER2 therapy. Conversely, high expression of luminal-related genes such as PGR, MDM2 or PIK3CA, or the PAM50 luminal intrinsic profile, was found associated with reduced benefit from single agent anti-HER2 therapy. Conclusions: Our data indicate that gene expression-based biomarkers can identify patients with HER2-positive metastatic breast cancer that benefit substantially from single agent chemo-free anti-HER2 targeted therapy. In the study presented here, a well-defined cohort of 21 breast cancer cases from the HERLAP trial, was used to acquire expression profiles of a total of 105 unique genes
Project description:Global downregulation of microRNAs (miRNAs) is commonly observed in human cancers and can have a causative role in tumorigenesis. The mechanisms responsible for this phenomenon remain poorly understood. Here we show that YAP, the downstream target of the tumor-suppressive Hippo signaling pathway regulates miRNA biogenesis in a cell density-dependent manner. At low cell density, nuclear YAP binds and sequesters p72 (DDX17), a regulatory component of the miRNA processing machinery. At high cell density, Hippo-mediated cytoplasmic retention of YAP facilitates p72 association with Microprocessor and binding to a specific sequence motif in pri-miRNAs. Inactivation of the Hippo pathway or expression of constitutively active YAP causes widespread miRNA suppression in cells and tumors and a corresponding post-transcriptional induction of MYC expression. Thus, the Hippo pathway links contact-inhibition regulation to miRNA biogenesis and may be responsible for the widespread miRNA repression observed in cancer. Two conditions (siCtrl and siYAP) were analyzed in duplicate.
Project description:Global downregulation of microRNAs (miRNAs) is commonly observed in human cancers and can have a causative role in tumorigenesis. The mechanisms responsible for this phenomenon remain poorly understood. Here we show that YAP, the downstream target of the tumor-suppressive Hippo signaling pathway regulates miRNA biogenesis in a cell density-dependent manner. At low cell density, nuclear YAP binds and sequesters p72 (DDX17), a regulatory component of the miRNA processing machinery. At high cell density, Hippo-mediated cytoplasmic retention of YAP facilitates p72 association with Microprocessor and binding to a specific sequence motif in pri-miRNAs. Inactivation of the Hippo pathway or expression of constitutively active YAP causes widespread miRNA suppression in cells and tumors and a corresponding post-transcriptional induction of MYC expression. Thus, the Hippo pathway links contact-inhibition regulation to miRNA biogenesis and may be responsible for the widespread miRNA repression observed in cancer. Four conditions (siCtrl, si p72, siNF2/LATS2 and siDROSHA/DGCR8) were analyzed in duplicate.
Project description:Global downregulation of microRNAs (miRNAs) is commonly observed in human cancers and can have a causative role in tumorigenesis. The mechanisms responsible for this phenomenon remain poorly understood. Here we show that YAP, the downstream target of the tumor-suppressive Hippo signaling pathway regulates miRNA biogenesis in a cell density-dependent manner. At low cell density, nuclear YAP binds and sequesters p72 (DDX17), a regulatory component of the miRNA processing machinery. At high cell density, Hippo-mediated cytoplasmic retention of YAP facilitates p72 association with Microprocessor and binding to a specific sequence motif in pri-miRNAs. Inactivation of the Hippo pathway or expression of constitutively active YAP causes widespread miRNA suppression in cells and tumors and a corresponding post-transcriptional induction of MYC expression. Thus, the Hippo pathway links contact-inhibition regulation to miRNA biogenesis and may be responsible for the widespread miRNA repression observed in cancer. Two conditions (transfection of p72 or control EGFP in addition to siRNAs for NF2 and LATS2) were analyzed in duplicate.