CDK4/6 inhibitors in combination with endocrine therapy are now used as front-line treatment for patients with estrogen-receptor positive (ER+) breast cancer. While this combination improves overall survival, the mechanisms of disease progression remain poorly understood. Here, we performed unbiased genome-wide CRISPR/Cas9 knockout screens using endocrine sensitive ER+ breast cancer cells to identify novel drivers of resistance to combination endocrine therapy (tamoxifen) and CDK4/6 inhibitor (palbociclib) treatment.
View Article and Find Full Text PDFNatural killer (NK) cell homeostasis and effector functions require context-dependent signaling via numerous receptors, including the interleukin-15 receptor (IL-15R). Post-translational modifications can regulate receptor signaling, impacting receptor turnover and trafficking. Core fucosylation is one such modification known to impact receptor expression and is uniquely mediated by fucosyltransferase 8 (FUT8).
View Article and Find Full Text PDFInterleukin-15 receptor (IL-15R) agonists induce anti-tumor immunity in pre-clinical models. However, dose-limiting toxicity has hampered their clinical development. We performed genome-wide CRISPR screens to reveal the complete IL-15R signaling mechanism in natural killer (NK) cells and discovered that ubiquitin-dependent IL-15R degradation is the dominant mechanism restraining IL-15R signaling.
View Article and Find Full Text PDFBackground: Organs and tissues need to be vascularized during development. Similarly, vascularization is required to engineer thick tissues. How vessels are formed during organogenesis is not fully understood, and vascularization of engineered tissues remains a significant challenge.
View Article and Find Full Text PDFAdenosine-to-inosine (A-to-I) editing of double-stranded RNA (dsRNA) by ADAR1 is an essential modifier of the immunogenicity of cellular dsRNA. The role of MDA5 in sensing unedited cellular dsRNA and the downstream activation of type I interferon (IFN) signaling are well established. However, we have an incomplete understanding of pathways that modify the response to unedited dsRNA.
View Article and Find Full Text PDFObjectives: Autologous chimeric antigen receptor (CAR) T-cell therapy of B-cell malignancies achieves long-term disease remission in a high fraction of patients and has triggered intense research into translating this successful approach into additional cancer types. However, the complex logistics involved in autologous CAR-T manufacturing, the compromised fitness of patient-derived T cells, the high rates of serious toxicities and the overall cost involved with product manufacturing and hospitalisation have driven innovation to overcome such hurdles. One alternative approach is the use of allogeneic natural killer (NK) cells as a source for CAR-NK cell therapy.
View Article and Find Full Text PDFThe mechanism of action of eprenetapopt (APR-246, PRIMA-1) as an anticancer agent remains unresolved, although the clinical development of eprenetapopt focuses on its reported mechanism of action as a mutant-p53 reactivator. Using unbiased approaches, this study demonstrates that eprenetapopt depletes cellular antioxidant glutathione levels by increasing its turnover, triggering a nonapoptotic, iron-dependent form of cell death known as ferroptosis. Deficiency in genes responsible for supplying cancer cells with the substrates for de novo glutathione synthesis (, , and ), as well as the enzymes required to synthesize glutathione ( and ), augments the activity of eprenetapopt.
View Article and Find Full Text PDFNeuroblastoma is a deadly childhood cancer arising in the developing sympathetic nervous system. High-risk patients are currently treated with intensive chemotherapy, which is curative in only 50% of children and leaves some surviving patients with life-long side effects. microRNAs (miRNAs) are critical regulators of neural crest development and are deregulated during neuroblastoma tumorigenesis, making miRNA-based drugs an attractive therapeutic avenue.
View Article and Find Full Text PDFCurrent strategies to target RNA splicing mutant myeloid cancers proposes targeting the remaining splicing apparatus. This approach has only been modestly sensitizing and is also toxic to non-mutant-bearing wild-type cells. To explore potentially exploitable genetic interactions with spliceosome mutations, we combined data mining and functional screening for synthetic lethal interactions with an Srsf2P95H/+ mutation.
View Article and Find Full Text PDFJ Microbiol Immunol Infect
August 2021
Human papilloma viruses (HPV) are the main culprit in cervical and oropharyngeal cancers. HPV positive (+) cancers are regarded as 'oncogene addicted', displaying an absolute requirement for the continued expression of the oncogenes for their viability owing their survival, and thus making these genes salient targets for developing specific therapeutic agents. There is a strong association between HPV and oropharyngeal squamous cell carcinomas (OPSCC), a subset of head and neck cancers (HNCs).
View Article and Find Full Text PDFBreast cancers display phenotypic and functional heterogeneity and several lines of evidence support the existence of cancer stem cells (CSCs) in certain breast cancers, a minor population of cells capable of tumor initiation and metastatic dissemination. Identifying factors that regulate the CSC phenotype is therefore important for developing strategies to treat metastatic disease. The Inhibitor of Differentiation Protein 1 (Id1) and its closely related family member Inhibitor of Differentiation 3 (Id3) (collectively termed Id) are expressed by a diversity of stem cells and are required for metastatic dissemination in experimental models of breast cancer.
View Article and Find Full Text PDFBreast Cancer Res
June 2020
Background: Basal-like breast cancer (BLBC) is a poorly characterised, heterogeneous disease. Patients are diagnosed with aggressive, high-grade tumours and often relapse with chemotherapy resistance. Detailed understanding of the molecular underpinnings of this disease is essential to the development of personalised therapeutic strategies.
View Article and Find Full Text PDFAlternative polyadenylation (APA) determines stability, localization and translation potential of the majority of mRNA in eukaryotic cells. The heterodimeric mammalian cleavage factor II (CF II) is required for pre-mRNA 3' end cleavage and is composed of the RNA kinase hClp1 and the termination factor hPcf11; the latter protein binds to RNA and the RNA polymerase II carboxy-terminal domain. Here, we used siRNA mediated knockdown and poly(A) targeted RNA sequencing to analyze the role of CF II in gene expression and APA in estrogen receptor positive MCF7 breast cancer cells.
View Article and Find Full Text PDFDocetaxel and cabazitaxel are taxane chemotherapy treatments for metastatic castration-resistant prostate cancer (CRPC). However, therapeutic resistance remains a major issue. MicroRNAs are short non-coding RNAs that can silence multiple genes, regulating several signalling pathways simultaneously.
View Article and Find Full Text PDFMethods Mol Biol
January 2019
This chapter details a compendium of protocols that collectively enable the reader to perform a pooled shRNA and/or CRISPR screen-with methods to identify and validate positive controls and subsequent hits; establish a viral titer in the cell line of choice; create and screen libraries, sequence strategies, and bioinformatics resources to analyze outcomes. Collectively, this provides an overarching resource from the start to finish of a screening project, making this technology possible in all laboratories.
View Article and Find Full Text PDFNucleic Acids Res
December 2017
Micro-RNAs (miRNAs) are potent regulators of gene expression and cellular phenotype. Each miRNA has the potential to target hundreds of transcripts within the cell thus controlling fundamental cellular processes such as survival and proliferation. Here, we exploit this important feature of miRNA networks to discover vulnerabilities in cancer phenotype, and map miRNA-target relationships across different cancer types.
View Article and Find Full Text PDFIt has recently been suggested that the chemokine receptor (CCR5) is required for bone marrow (BM) derived endothelial progenitor cell (EPC) mediated angiogenesis. Here we show that suppression of either cancer cell produced CCL5, or host CCR5 leads to distinctive vascular and tumor growth defects in breast cancer. Surprisingly, CCR5 restoration in the BM alone was not sufficient to rescue the wild type phenotype, suggesting that impaired tumor growth associated with inhibiting CCL5/CCR5 is not due to defects in EPC biology.
View Article and Find Full Text PDFIntroduction: The study of mammalian development has offered many insights into the molecular aetiology of cancer. We previously used analysis of mammary morphogenesis to discover a critical role for GATA-3 in mammary developmental and carcinogenesis. In recent years an important role for microRNAs (miRNAs) in a myriad of cellular processes in development and in oncogenesis has emerged.
View Article and Find Full Text PDFBasal-like breast cancer (BLBC) is a heterogeneous disease with poor prognosis; however, its cellular origins and aetiology are poorly understood. In this study, we show that inhibitor of differentiation 4 (ID4) is a key regulator of mammary stem cell self-renewal and marks a subset of BLBC with a putative mammary basal cell of origin. Using an ID4GFP knock-in reporter mouse and single-cell transcriptomics, we show that ID4 marks a stem cell-enriched subset of the mammary basal cell population.
View Article and Find Full Text PDFIntroduction: The lateral circumflex femoral artery usually originates from the lateral side of the initial part of the deep femoral artery, or less frequently from the femoral artery. If it is a branch of the femoral artery, it arises directly above the point of origin of the deep femoral artery. The aim of this study was to determine the origin of the lateral circumflex femoral artery, its origin distance from the midpoint of the inguinal ligament and the topographical relations of the origin, which have a great significance in clinical work.
View Article and Find Full Text PDFAngiogenesis, defined as blood vessel formation from a preexisting vasculature, is governed by multiple signal cascades including integrin receptors, in particular integrin αVβ3. Here we identify the endothelial cell (EC)-secreted factor epidermal growth factor-like protein 7 (EGFL7) as a novel specific ligand of integrin αVβ3, thus providing mechanistic insight into its proangiogenic actions in vitro and in vivo. Specifically, EGFL7 attaches to the extracellular matrix and by its interaction with integrin αVβ3 increases the motility of EC, which allows EC to move on a sticky underground during vessel remodeling.
View Article and Find Full Text PDFBlood vessels form de novo through the tightly regulated programs of vasculogenesis and angiogenesis. Both processes are distinct but one of the steps they share is the formation of a central lumen, when groups of cells organized as vascular cords undergo complex changes to achieve a tube-like morphology. Recently, a protein termed epidermal growth factor-like domain 7 (EGFL7) was described as a novel endothelial cell-derived factor involved in the regulation of the spatial arrangement of cells during vascular tube assembly.
View Article and Find Full Text PDFEpidermal growth factor-like domain 7 (EGFL7) is a secreted factor implicated in cellular responses such as cell migration and blood vessel formation; however the molecular mechanisms underlying the effects of EGFL7 are largely unknown. Here we have identified transmembrane receptors of the Notch family as EGFL7-binding molecules. Secreted EGFL7 binds to a region in Notch involved in ligand-mediated receptor activation, thus acting as an antagonist of Notch signalling.
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