scholarly journals The Role of Alternative RNA Splicing in the Regulation of hTERT, Telomerase, and Telomeres: Implications for Cancer Therapeutics

Cancers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1514 ◽  
Author(s):  
Aaron L. Slusher ◽  
Jeongjin JJ Kim ◽  
Andrew T. Ludlow
Keyword(s):  
Cancer Cell ◽  
Rna Splicing ◽  
Cell Biology ◽  
Science Studies ◽  
De Novo ◽  
Treatment Strategies ◽  
Cancer Therapeutics ◽  
Telomerase Activity ◽  
Splice Isoforms ◽  
Alternatively Spliced

Alternative RNA splicing impacts the majority (>90%) of eukaryotic multi-exon genes, expanding the coding capacity and regulating the abundance of gene isoforms. Telomerase (hTERT) is a key example of a gene that is alternatively spliced during human fetal development and becomes dysregulated in nearly all cancers. Approximately 90% of human tumors use telomerase to synthesize de novo telomere repeats and obtain telomere-dependent cellular immortality. Paradigm shifting data indicates that hTERT alternative splicing, in addition to transcription, plays an important role in the regulation of active telomerase in cells. Our group and others are pursuing the basic science studies to progress this emerging area of telomerase biology. Recent evidence demonstrates that switching splicing of hTERT from the telomerase activity producing full-length hTERT isoform to alternatively spliced, non-coding isoforms may be a novel telomerase inhibition strategy to prevent cancer growth and survival. Thus, the goals of this review are to detail the general roles of telomerase in cancer development, explore the emerging regulatory mechanisms of alternative RNA splicing of the hTERT gene in various somatic and cancer cell types, define the known and potential roles of hTERT splice isoforms in cancer cell biology, and provide insight into new treatment strategies targeting hTERT in telomerase-positive cancers.

scholarly journals Genetic and Genomic Landscape of Secondary and Therapy-Related Acute Myeloid Leukemia

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 749 ◽  
Author(s):  
Alexandra Higgins ◽  
Mithun Vinod Shah
Keyword(s):  
Acute Myeloid Leukemia ◽  
Clinical Features ◽  
Rna Splicing ◽  
Myeloid Leukemia ◽  
De Novo ◽  
Epigenetic Modification ◽  
Treatment Strategies ◽  
Molecular Techniques ◽  
De Novo Aml ◽  
Acute Myeloid

A subset of acute myeloid leukemia (AML) arises either from an antecedent myeloid malignancy (secondary AML, sAML) or as a complication of DNA-damaging therapy for other cancers (therapy-related myeloid neoplasm, t-MN). These secondary leukemias have unique biological and clinical features that distinguish them from de novo AML. Over the last decade, molecular techniques have unraveled the complex subclonal architecture of sAML and t-MN. In this review, we compare and contrast biological and clinical features of de novo AML with sAML and t-MN. We discuss the role of genetic mutations, including those involved in RNA splicing, epigenetic modification, tumor suppression, transcription regulation, and cell signaling, in the pathogenesis of secondary leukemia. We also discuss clonal hematopoiesis in otherwise healthy individuals, as well as in the context of another malignancy, and how it challenges the conventional notion of sAML/t-MN. We conclude by summarizing the current and emerging treatment strategies, including allogenic transplant, in these complex scenarios.

scholarly journals Oncogenic fusion protein EWS-FLI1 is a network hub that regulates alternative splicing

2015 ◽  
Vol 112 (11) ◽  
pp. E1307-E1316 ◽  
Author(s):  
Saravana P. Selvanathan ◽  
Garrett T. Graham ◽  
Hayriye V. Erkizan ◽  
Uta Dirksen ◽  
Thanemozhi G. Natarajan ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Protein Interactions ◽  
Rna Splicing ◽  
Rna Binding ◽  
Expression Patterns ◽  
Human Mesenchymal Stem Cells ◽  
Exon Array ◽  
Telomerase Activity ◽  
Specific Protein ◽  
Alternatively Spliced

The synthesis and processing of mRNA, from transcription to translation initiation, often requires splicing of intragenic material. The final mRNA composition varies based on proteins that modulate splice site selection. EWS-FLI1 is an Ewing sarcoma (ES) oncoprotein with an interactome that we demonstrate to have multiple partners in spliceosomal complexes. We evaluate the effect of EWS-FLI1 on posttranscriptional gene regulation using both exon array and RNA-seq. Genes that potentially regulate oncogenesis, including CLK1, CASP3, PPFIBP1, and TERT, validate as alternatively spliced by EWS-FLI1. In a CLIP-seq experiment, we find that EWS-FLI1 RNA-binding motifs most frequently occur adjacent to intron–exon boundaries. EWS-FLI1 also alters splicing by directly binding to known splicing factors including DDX5, hnRNP K, and PRPF6. Reduction of EWS-FLI1 produces an isoform of γ-TERT that has increased telomerase activity compared with wild-type (WT) TERT. The small molecule YK-4–279 is an inhibitor of EWS-FLI1 oncogenic function that disrupts specific protein interactions, including helicases DDX5 and RNA helicase A (RHA) that alters RNA-splicing ratios. As such, YK-4–279 validates the splicing mechanism of EWS-FLI1, showing alternatively spliced gene patterns that significantly overlap with EWS-FLI1 reduction and WT human mesenchymal stem cells (hMSC). Exon array analysis of 75 ES patient samples shows similar isoform expression patterns to cell line models expressing EWS-FLI1, supporting the clinical relevance of our findings. These experiments establish systemic alternative splicing as an oncogenic process modulated by EWS-FLI1. EWS-FLI1 modulation of mRNA splicing may provide insight into the contribution of splicing toward oncogenesis, and, reciprocally, EWS-FLI1 interactions with splicing proteins may inform the splicing code.

Chemokines: Brief review and its Role in Cancer Cell Biology

2012 ◽  
Vol 2 (12) ◽  
pp. 415-416
Author(s):  
Dr. Priyanka R Prasad ◽  
◽  
Dr. Anju N Duttargi ◽  
Dr. Sreeshyla H.S Dr. Sreeshyla H.S ◽  
Dr. Usha Hegde ◽  
...  
Keyword(s):  
Cancer Cell ◽  
Cell Biology

ARFGAP3 an androgen target gene promotes prostate cancer cell proliferation and migration.

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Cell Proliferation ◽  
Cancer Cell ◽  
Cell Biology ◽  
Adaptor Protein ◽  
Cancer Cell Proliferation ◽  
Lncap Cells ◽  
Gtpase Activating Protein ◽  
Cell Proliferation And Migration ◽  
And Migration ◽  
Proliferation And Migration

ADP ribosylation factor GTPase-activating protein 3 (ARFGAP3) is a GTPase-activating protein that associates with the Golgiapparatus and regulates the vesicular trafficking pathway. In the present study, we examined the contribution of ARFGAP3 toprostate cancer cell biology. We showed that ARFGAP3 expression was induced by 100 nM of dihydrotestosterone (DHT) atboth the mRNA and protein levels in androgen-sensitive LNCaP cells. We generated stable transfectants of LNCaP cells withFLAG-tagged ARFGAP3 or a control empty vector and showed that ARFGAP3 overexpression promoted cell proliferation andmigration compared with control cells. We found that ARFGAP3 interacted with paxillin, a focal adhesion adaptor protein thatis important for cell mobility and migration. Small interfering RNA (siRNA)-mediated knockdown of ARFGAP3 showed thatARFGAP3 siRNA markedly reduced LNCaP cell growth. Androgen receptor (AR)-dependent transactivation activity on prostatespecificantigen (PSA) enhancer was synergistically promoted by exogenous ARFGAP3 and paxillin expression, as shown byluciferase assay in LNCaP cells. Thus, our results suggest that ARFGAP3 is a novel androgen-regulated gene that can promoteprostate cancer cell proliferation and migration in collaboration with paxillin.

Eating Green: Shining Light on the Use of Dietary Phytochemicals as a Modern Approach in the Prevention and Treatment of Head and Neck Cancers

2018 ◽  
Vol 18 (3) ◽  
pp. 182-191 ◽  
Author(s):  
Linda L. Eastham ◽  
Candace M. Howard ◽  
Premalatha Balachandran ◽  
David S. Pasco ◽  
Pier Paolo Claudio
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Head And Neck ◽  
Cancer Cell ◽  
Squamous Cell ◽  
Treatment Strategies ◽  
Lifestyle Changes ◽  
Neck Squamous Cell Carcinoma ◽  
Laboratory Research ◽  
Modern Approach

Enthusiasm for the use of dietary bioactive compounds as chemopreventive agents and adjuvants for current therapies has increased laboratory research conducted on several types of cancers including Head and Neck Squamous Cell Carcinoma (HNSCC). The green chemoprevention movement is a modern approach to highlight healthy lifestyle changes that aim to decrease the incidence of HNSCC. A healthy diet can be an effective way to prevent the development of oral cancers. Discovery of the naturally occurring plant based compounds called phytochemicals has facilitated the development of new treatment strategies for patients that are at risk for, or have developed HNSCC. Many of these compounds have been shown to elicit very potent anti-carcinogenic properties. While there are many compounds that have been studied, the compounds from two specific categories of phytochemicals, phenolics (resveratrol, EGCG, curcumin, quercetin, and honokiol) and glucosinolates (sulforaphane, PEITC and BITC), are emerging as potent and effective inhibitors of oral carcinogenesis. These compounds have been shown to inhibit HNSCC growth through a variety of mechanisms. Research has demonstrated that these compounds can regulate cancer cell proliferation through the regulation of multiple cell signaling pathways. They can impede cell cycle progression, induce differentiation and apoptosis, prevent angiogenesis, and inhibit cancer cell invasive and metastatic properties. They can protect normal cells during treatment and reduce the damage caused by chemotherapy and radiotherapy. This review aims to provide an overview of some of the most effective phytochemicals that have the potential to successfully prevent and treat head and neck squamous cell carcinoma.

Statins and Protein Prenylation in Cancer Cell Biology and Therapy

2012 ◽  
Vol 12 (4) ◽  
pp. 303-315 ◽  
Author(s):  
Carmen Garcia-Ruiz ◽  
Albert Morales ◽  
Jose C. Fernandez-Checa
Keyword(s):  
Cancer Cell ◽  
Cell Biology ◽  
Protein Prenylation

An Unbiased Predictive Model to Detect DNA Methylation Propensity of CpG Islands in the Human Genome

2020 ◽  
Vol 15 ◽  
Author(s):  
Dicle Yalcin ◽  
Hasan H. Otu
Keyword(s):  
Model Building ◽  
De Novo ◽  
Cpg Islands ◽  
Treatment Strategies ◽  
Area Under The Curve ◽  
Global Methylation ◽  
Sequence Features ◽  
A Genome ◽  
Combined Features ◽  
Epigenetic Repression

Background: Epigenetic repression mechanisms play an important role in gene regulation, specifically in cancer development. In many cases, a CpG island’s (CGI) susceptibility or resistance to methylation are shown to be contributed by local DNA sequence features. Objective: To develop unbiased machine learning models–individually and combined for different biological features–that predict the methylation propensity of a CGI. Methods: We developed our model consisting of CGI sequence features on a dataset of 75 sequences (28 prone, 47 resistant) representing a genome-wide methylation structure. We tested our model on two independent datasets that are chromosome (132 sequences) and disease (70 sequences) specific. Results: We provided improvements in prediction accuracy over previous models. Our results indicate that combined features better predict the methylation propensity of a CGI (area under the curve (AUC) ~0.81). Our global methylation classifier performs well on independent datasets reaching an AUC of ~0.82 for the complete model and an AUC of ~0.88 for the model using select sequences that better represent their classes in the training set. We report certain de novo motifs and transcription factor binding site (TFBS) motifs that are consistently better in separating prone and resistant CGIs. Conclusion: Predictive models for the methylation propensity of CGIs lead to a better understanding of disease mechanisms and can be used to classify genes based on their tendency to contain methylation prone CGIs, which may lead to preventative treatment strategies. MATLAB and Python™ scripts used for model building, prediction, and downstream analyses are available at https://github.com/dicleyalcin/methylProp_predictor.

The Impact of Translational Research in Breast Cancer Care: Can we Improve the Therapeutic Scenario?

2018 ◽  
Vol 18 (6) ◽  
pp. 832-836
Author(s):  
Giuseppe Buono ◽  
Francesco Schettini ◽  
Francesco Perri ◽  
Grazia Arpino ◽  
Roberto Bianco ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Translational Research ◽  
Cell Biology ◽  
Cancer Biology ◽  
Hormone Receptors ◽  
Treatment Strategies ◽  
Growth Factor Receptor ◽  
Molecular Heterogeneity ◽  
Therapeutic Implications ◽  
The Impact

Traditionally, breast cancer (BC) is divided into different subtypes defined by immunohistochemistry (IHC) according to the expression of hormone receptors and overexpression/amplification of human epidermal growth factor receptor 2 (HER2), with crucial therapeutic implications. In the last few years, the definition of different BC molecular subgroups within the IHC-defined subtypes and the identification of the important role that molecular heterogeneity can play in tumor progression and treatment resistance have inspired the search for personalized therapeutic approaches. In this scenario, translational research represents a key strategy to apply knowledge from cancer biology to the clinical setting, through the study of all the tumors “omics”, including genomics, transcriptomics, proteomics, epigenomics, and metabolomics. Importantly, the introduction of new high-throughput technologies, such as next generation sequencing (NGS) for the study of cancer genome and transcriptome, greatly amplifies the potential and the applications of translational research in the oncology field. Moreover, the introduction of new experimental approaches, such as liquid biopsy, as well as new-concept clinical trials, such as biomarker-driven adaptive studies, may represent a turning point for BC translational research. </P><P> It is likely that translational research will have in the near future a significant impact on BC care, especially by giving us the possibility to dissect the complexity of tumor cell biology and develop new personalized treatment strategies.

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