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Signal Transduction and Targeted Therapy Feb 2021The abnormal regulation of alternative splicing is usually accompanied by the occurrence and development of tumors, which would produce multiple different isoforms and...
The abnormal regulation of alternative splicing is usually accompanied by the occurrence and development of tumors, which would produce multiple different isoforms and diversify protein expression. The aim of the present study was to conduct a systematic review in order to describe the regulatory mechanisms of alternative splicing, as well as its functions in tumor cells, from proliferation and apoptosis to invasion and metastasis, and from angiogenesis to metabolism. The abnormal splicing events contributed to tumor progression as oncogenic drivers and/or bystander factors. The alterations in splicing factors detected in tumors and other mis-splicing events (i.e., long non-coding and circular RNAs) in tumorigenesis were also included. The findings of recent therapeutic approaches targeting splicing catalysis and splicing regulatory proteins to modulate pathogenically spliced events (including tumor-specific neo-antigens for cancer immunotherapy) were introduced. The emerging RNA-based strategies for the treatment of cancer with abnormally alternative splicing isoforms were also discussed. However, further studies are still required to address the association between alternative splicing and cancer in more detail.
Topics: Alternative Splicing; Carcinogenesis; Gene Expression Regulation, Neoplastic; Humans; Neoplasms; RNA Splicing; RNA Splicing Factors; RNA, Circular
PubMed: 33623018
DOI: 10.1038/s41392-021-00486-7 -
Journal of Cancer Research and Clinical... Dec 2023During eukaryotic gene expression, alternative splicing of messenger RNA precursors is critical in increasing protein diversity and regulatory complexity. Multiple... (Review)
Review
During eukaryotic gene expression, alternative splicing of messenger RNA precursors is critical in increasing protein diversity and regulatory complexity. Multiple transcript isoforms could be produced by alternative splicing from a single gene; they could eventually be translated into protein isoforms with deleted, added, or altered domains or produce transcripts containing premature termination codons that could be targeted by nonsense-mediated mRNA decay. Alternative splicing can generate proteins with similar, different, or even opposite functions. Increasingly strong evidence indicates that abnormal RNA splicing is a prevalent and crucial occurrence in cellular differentiation, tissue advancement, and the development and progression of cancer. Aberrant alternative splicing could affect cancer cell activities such as growth, apoptosis, invasiveness, drug resistance, angiogenesis, and metabolism. This systematic review provides a comprehensive overview of the impact of abnormal RNA alternative splicing on the development and progression of hepatocellular carcinoma.
Topics: Humans; Alternative Splicing; RNA; Carcinoma, Hepatocellular; RNA, Messenger; Liver Neoplasms; Protein Isoforms; RNA Splicing
PubMed: 37898981
DOI: 10.1007/s00432-023-05474-8 -
Serine-Arginine Protein Kinase 1 (SRPK1): a systematic review of its multimodal role in oncogenesis.Molecular and Cellular Biochemistry Oct 2022Alternative splicing is implicated in each of the hallmarks of cancer, and is mechanised by various splicing factors. Serine-Arginine Protein Kinase 1 (SRPK1) is an... (Review)
Review
Alternative splicing is implicated in each of the hallmarks of cancer, and is mechanised by various splicing factors. Serine-Arginine Protein Kinase 1 (SRPK1) is an enzyme which moderates the activity of splicing factors rich in serine/arginine domains. Here we review SRPK1's relationship with various cancers by performing a systematic review of all relevant published data. Elevated SRPK1 expression correlates with advanced disease stage and poor survival in many epithelial derived cancers. Numerous pre-clinical studies investigating a host of different tumour types; have found increased SRPK1 expression to be associated with proliferation, invasion, migration and apoptosis in vitro as well as tumour growth, tumourigenicity and metastasis in vivo. Aberrant SRPK1 expression is implicated in various signalling pathways associated with oncogenesis, a number of which, such as the PI3K/AKT, NF-КB and TGF-Beta pathway, are implicated in multiple different cancers. SRPK1-targeting micro RNAs have been identified in a number of studies and shown to have an important role in regulating SRPK1 activity. SRPK1 expression is also closely related to the response of various tumours to platinum-based chemotherapeutic agents. Future clinical applications will likely focus on the role of SRPK1 as a biomarker of treatment resistance and the potential role of its inhibition.
Topics: Arginine; Arginine Kinase; Carcinogenesis; Cell Transformation, Neoplastic; Humans; NF-kappa B; Neoplasms; Phosphatidylinositol 3-Kinases; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; RNA Splicing Factors; Serine; Transforming Growth Factor beta
PubMed: 35583632
DOI: 10.1007/s11010-022-04456-7 -
International Journal of Molecular... Feb 2023Among the most common muscular dystrophies in adults is Myotonic Dystrophy type 1 (DM1), an autosomal dominant disorder characterized by myotonia, muscle wasting and... (Review)
Review
Among the most common muscular dystrophies in adults is Myotonic Dystrophy type 1 (DM1), an autosomal dominant disorder characterized by myotonia, muscle wasting and weakness, and multisystemic dysfunctions. This disorder is caused by an abnormal expansion of the CTG triplet at the gene that, when transcribed to expanded mRNA, can lead to RNA toxic gain of function, alternative splicing impairments, and dysfunction of different signaling pathways, many regulated by protein phosphorylation. In order to deeply characterize the protein phosphorylation alterations in DM1, a systematic review was conducted through PubMed and Web of Science databases. From a total of 962 articles screened, 41 were included for qualitative analysis, where we retrieved information about total and phosphorylated levels of protein kinases, protein phosphatases, and phosphoproteins in DM1 human samples and animal and cell models. Twenty-nine kinases, 3 phosphatases, and 17 phosphoproteins were reported altered in DM1. Signaling pathways that regulate cell functions such as glucose metabolism, cell cycle, myogenesis, and apoptosis were impaired, as seen by significant alterations to pathways such as AKT/mTOR, MEK/ERK, PKC/CUGBP1, AMPK, and others in DM1 samples. This explains the complexity of DM1 and its different manifestations and symptoms, such as increased insulin resistance and cancer risk. Further studies can be done to complement and explore in detail specific pathways and how their regulation is altered in DM1, to find what key phosphorylation alterations are responsible for these manifestations, and ultimately to find therapeutic targets for future treatments.
Topics: Animals; Adult; Humans; Myotonic Dystrophy; Phosphorylation; Alternative Splicing; RNA, Messenger; Muscular Atrophy; Muscle, Skeletal
PubMed: 36834509
DOI: 10.3390/ijms24043091 -
Technology in Cancer Research &... 2021The purpose of this meta-analysis was to study the prognostic effects of androgen receptor splicing variant 7 (AR-V7) on metastatic castration-resistant prostate cancer... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
The purpose of this meta-analysis was to study the prognostic effects of androgen receptor splicing variant 7 (AR-V7) on metastatic castration-resistant prostate cancer (mCRPC) under different treatment options (chemotherapy, hormone therapy).
METHODS
We conducted a systematic search of PubMed, EMBASE and Cochrane databases for clinical studies up to June 4, 2021, and used prostate-specific antigen (PSA) progression free-survival (PSA-PFS), radiologic PFS (r-PFS), overall survival (OS) and PSA response rate (PSA RR) as the main endpoints. Subgroup analyses were conducted based on the source of the specimens. STATA v.15 software was used for data analysis.
RESULTS
Twenty-one studies were included in this meta-analysis, with a total of 1578 samples. In the abiraterone (AA)/enzalutamide (E) treatment group, AR-V7 positive patients had worse PSA-PFS (hazard ratio [HR] = 3.40; 95% confidence interval [95%CI] 2.56-4.51; < 0.05) and worse r-PFS (HR = 2.69; 95%CI 1.70-4.24; < 0.05) and OS (HR = 3.02; 95%CI 1.73-5.30; < 0.05). Multivariate Cox regression results showed that AR-V7 positive status was an independent risk factor for OS in the AA/E treatment group. In the taxane treatment group, AR-V7-positive and negative patients had similar PSA-PFS (HR = 0.87; 95%CI 0.46-1.63; = 0.657), r-PFS (HR = 1.01; 95%CI 0.53-1.96; = 0.965) and OS (HR = 1.50; 95%CI 0.89-2.52; = 0.127). For AR-V7-positive patients, the difference in OS between taxane and AA/E treatment was not statistically significant (HR = 1.03; 95%CI 0.52-2.06; = 0.930). However, multivariate Cox regression results suggested that for AR-V7-positive patients, taxane therapy was a protective factor for OS (HR = 0.35; 95%CI 0.20-0.60; < 0.05).
CONCLUSION
The expression of AR-V7 indicates a poor prognosis and is an independent risk factor for OS in AA/E-treated mCRPC patients. However, AR-V7 positive status does not play the same role in taxane-treated patients. In addition, compared to AA/E, taxane treatment is a protective factor for OS in AR-V7-positive patients. AR-V7 may thus be an effective biomarker for treatment prognosis in patients with mCRPC.
Topics: Alternative Splicing; Biomarkers, Tumor; Humans; Male; Prognosis; Proportional Hazards Models; Prostatic Neoplasms, Castration-Resistant; RNA Isoforms; Receptors, Androgen
PubMed: 34313171
DOI: 10.1177/15330338211035260 -
Prostate Cancer and Prostatic Diseases Sep 2020The androgen receptor (AR) is a key prostate cancer drug target. Suppression of AR signaling mediated by the full-length AR (AR-FL) is the therapeutic goal of all...
BACKGROUND
The androgen receptor (AR) is a key prostate cancer drug target. Suppression of AR signaling mediated by the full-length AR (AR-FL) is the therapeutic goal of all existing AR-directed therapies. AR-targeting agents impart therapeutic benefit, but lead to AR aberrations that underlie disease progression and therapeutic resistance. Among the AR aberrations specific to castration-resistant prostate cancer (CRPC), AR variants (AR-Vs) have emerged as important indicators of disease progression and therapeutic resistance.
METHODS
We conducted a systemic review of the literature focusing on recent laboratory studies on AR-Vs following our last review article published in 2016. Topics ranged from measurement and detection, molecular origin, regulation, genomic function, and preclinical therapeutic targeting of AR-Vs. We provide expert opinions and perspectives on these topics.
RESULTS
Transcript sequences for 22 AR-Vs have been reported in the literature. Different AR-Vs may arise through different mechanisms, and can be regulated by splicing factors and dictated by genomic rearrangements, but a low-androgen environment is a prerequisite for generation of AR-Vs. The unique transcript structures allowed development of in situ and in-solution measurement and detection methods, including mRNA and protein detection, in both tissue and blood specimens. AR-V7 remains the main measurement target and the most extensively characterized AR-V. Although AR-V7 coexists with AR-FL, genomic functions mediated by AR-V7 do not require the presence of AR-FL. The distinct cistromes and transcriptional programs directed by AR-V7 and their coregulators are consistent with genomic features of progressive disease in a low-androgen environment. Preclinical development of AR-V-directed agents currently focuses on suppression of mRNA expression and protein degradation as well as targeting of the amino-terminal domain.
CONCLUSIONS
Current literature continues to support AR-Vs as biomarkers and therapeutic targets in prostate cancer. Laboratory investigations reveal both challenges and opportunities in targeting AR-Vs to overcome resistance to current AR-directed therapies.
Topics: Alternative Splicing; Androgen Receptor Antagonists; Antineoplastic Combined Chemotherapy Protocols; Biomarkers, Tumor; Clinical Decision-Making; Drug Resistance, Neoplasm; Gene Expression Regulation, Neoplastic; Genetic Testing; Humans; Male; Precision Medicine; Progression-Free Survival; Prostatic Neoplasms, Castration-Resistant; Protein Isoforms; Proteolysis; Receptors, Androgen; Transcriptional Activation
PubMed: 32139878
DOI: 10.1038/s41391-020-0217-3 -
American Journal of Medical Genetics.... Jul 2020Variations in SLC9A9 gene expression and protein function are associated with multiple human diseases, which range from Attention-deficit/hyperactivity disorder (ADHD)...
Variations in SLC9A9 gene expression and protein function are associated with multiple human diseases, which range from Attention-deficit/hyperactivity disorder (ADHD) to glioblastoma multiforme. In an effort to determine the full spectrum of human disease associations with SLC9A9, we performed a systematic review of the literature. We also review SLC9A9's biochemistry, protein structure, and function, as well as its interacting partners with the goal of identifying mechanisms of disease and druggable targets. We report gaps in the literature regarding the genes function along with consistent trends in disease associations that can be used to further research into treating the respective diseases. We report that SLC9A9 has strong associations with neuropsychiatric diseases and various cancers. Interestingly, we find strong overlap in SLC9A9 disease associations and propose a novel role for SLC9A9 in neuropsychiatric comorbidity. In conclusion, SLC9A9 is a multifunctional protein that, through both its endosome regulatory function and its protein-protein interaction network, has the ability to modulate signaling axes, such as the PI3K pathway, among others.
Topics: Alternative Splicing; Attention Deficit Disorder with Hyperactivity; Autism Spectrum Disorder; Autophagy; Comorbidity; Exons; Genetic Predisposition to Disease; HEK293 Cells; Humans; Mental Disorders; Phosphatidylinositol 3-Kinases; Protein Interaction Mapping; Protein Processing, Post-Translational; Signal Transduction; Sodium-Hydrogen Exchangers
PubMed: 32400953
DOI: 10.1002/ajmg.b.32787 -
Prostate Cancer and Prostatic Diseases Sep 2020Approximately 10-30% of men with mCRPC will test positive for AR-V7 using one of two analytically and clinically validated circulating tumor cell (CTC)-based assays....
BACKGROUND
Approximately 10-30% of men with mCRPC will test positive for AR-V7 using one of two analytically and clinically validated circulating tumor cell (CTC)-based assays. These men have poor outcomes with approved AR-targeting therapies but may retain sensitivity to chemotherapy. Here, we discuss the clinical implications of testing and strategies that may benefit AR splice variant (AR-V)-positive men and discuss whether such variants are passengers or drivers of aggressive clinical behavior.
METHODS
We conducted a systemic review of the literature, covering updates since our 2016 review on androgen receptor variants in mCRPC, outcomes, and existing and novel approaches to therapy. We provide an expert opinion about management strategies for AR-V7-positive men and key unanswered research questions.
RESULTS
AR-V7-positive men, defined by Epic nuclear protein detection or the modified AdnaTest mRNA detection in CTCs, identify a subset of men with mCRPC that have a low probability of response to AR-targeting therapy with short progression-free and overall survival in multivariable analyses. AR-variants do not exist in isolation, but rather in the context of a complex, heterogeneous, and evolving mCRPC genome and phenotype as well as patient-specific clinical heterogeneity, and multiple mechanisms of resistance likely exist in patients regardless of AR-V7 detection. Efforts to develop broader resistance assays are needed, and effective treatment strategies beyond taxanes are needed to address the causal driver role of AR-variants and to benefit patients with AR-V-expressing prostate cancer.
CONCLUSIONS
CTC AR-V7 detection using the AdnaTest mRNA or Epic nuclear protein assays represents the first analytically and prospective clinically validated liquid biopsy assays that may inform treatment decisions in men with mCRPC, particularly after failure of first-line AR-therapy. The importance of AR-variants is likely to increase with the earlier use of AR-targeting strategies in other settings, and novel interventions for these men are needed.
Topics: Alternative Splicing; Androgen Receptor Antagonists; Antineoplastic Combined Chemotherapy Protocols; Clinical Decision-Making; Drug Resistance, Neoplasm; Genetic Testing; Humans; Male; Precision Medicine; Progression-Free Survival; Prostatic Neoplasms, Castration-Resistant; Protein Isoforms; Receptors, Androgen
PubMed: 32094489
DOI: 10.1038/s41391-020-0215-5 -
Gene May 2020Osteogenesis imperfecta (OI) is a rare disease characterized by increased bone fragility and predisposition to fractures, bone deformities and other major signs such as...
Rare splicing mutation in COL1A1 gene identified by whole exomes sequencing in a patient with osteogenesis imperfecta type I followed by prenatal diagnosis: A case report and review of the literature.
BACKGROUND
Osteogenesis imperfecta (OI) is a rare disease characterized by increased bone fragility and predisposition to fractures, bone deformities and other major signs such as dentinogenesis imperfecta, blue sclera and deafness. Over 90% of OI cases are caused by mutations in the COL1A1 and COL1A2 genes and the inheritance is autosomal dominant.
METHODS
We present a case of a couple requesting genetic counseling, because the man was diagnosed with OI on a clinical and radiological basis and the woman was pregnant. Whole exomes sequencing (WES) was performed in order to identify the mutation (s), followed by prenatal diagnosis.
RESULTS
WES identified a rare splicing mutation c.1155 + 1G > C in the COL1A1 gene recognized to be pathogenic and subsequently confirmed by next generation sequencing. The carrier state of the mutation was excluded for the fetus, so the pregnancy was further pursued and a healthy baby was born at term.
CONCLUSIONS
WES is a new and effective technique for detecting pathogenic variants in monogenic diseases and it is preferable to use such a technique in diseases with genetic heterogeneity especially when time does not allow another time-consuming diagnostic technique such classical Sanger sequencing. WES offers possibility to expand the global spectrum of OI pathogenic variants enabling the diagnosis of the disease.
Topics: Adult; Alternative Splicing; Collagen Type I; Collagen Type I, alpha 1 Chain; Exome; Female; Genotype; High-Throughput Nucleotide Sequencing; Humans; Male; Mutation; Osteogenesis Imperfecta; Pedigree; Pregnancy; Prenatal Diagnosis; Protein Isoforms; Exome Sequencing
PubMed: 32165296
DOI: 10.1016/j.gene.2020.144565