Alternative splicing of Krüppel-like factor 6 (KLF6) enriched in human androgen-deprived prostate cancer (PC).

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e15191-e15191
Author(s):  
XiaoMei Liu ◽  
Alejandro Gomez-Pinillos ◽  
Charisse Loder ◽  
Enrique Carrillo-de Santa Pau ◽  
Rui Fang Quiao ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Transcriptional Activity ◽  
Splice Variants ◽  
Tissue Banks ◽  
Lncap Cells ◽  
Transactivation Activity ◽  
Castrate Resistant ◽  
Mtt Assays ◽  
Proliferative Advantage

e15191 Background: Inactivation of KLF6 by mutations and alternative splicing has been implicated in PC. However, there are significant discrepancies among human PC studies concerning the prevalence and significance of KLF6 mutations, and the prevalence of splice variants (SVs) has not been established. The objective of this study was to assess the prevalence and role of KLF6 splicing in human PC progression. Methods: Human specimens were obtained from the tissue banks of three institutions. Representative epithelium of 74 frozen PC specimens [25 primary hormone-naïve (HN) PCs, 21 primary hormone-deprived (HD) PCs, 6 castrate-resistant metastases] and 22 normal prostates (NPs) were microdissected. KLF6 cDNA was amplified by PCR, cloned and sequenced in both forward and reverse directions and compared to the KLF6 GenBank sequence. The transcriptional activity of KLF6 SVs was evaluated in co-transfection assays with a p21-reporter, and their effect on LNCaP cell growth was determined by MTT assays. Results: Sixteen different SVs were identified: 13 were novel; 14 affected the DNA binding domain (DBD) and were transcriptionally inactive. The incidence of SVs was increased in PC versus NP (75% vs 45%; p=0.01) and in HD-PC versus HN-PC (90% vs 64%; p=0.04) HD-PC were significantly enriched in SVs lacking the DBD. Forced expression of dysfunctional KLF6 SVs increased growth of LNCaP cells in androgen-depleted media. Conclusions: KLF6 SVs lacking p21-reporter transactivation activity occur in NP epithelium but are markedly increased in incidence, variety and level of expression in PC tissues that survive androgen-deprivation. This enrichment may enable resistance to hormone therapy and a proliferative advantage under castrate conditions.

Role of RYR3 splice variants in calcium signaling in mouse nonpregnant and pregnant myometrium

2007 ◽  
Vol 293 (3) ◽  
pp. C848-C854 ◽  
Author(s):  
Fabrice Dabertrand ◽  
Nicolas Fritz ◽  
Jean Mironneau ◽  
Nathalie Macrez ◽  
Jean-Luc Morel
Keyword(s):  
Alternative Splicing ◽  
Antisense Oligonucleotides ◽  
Splice Variants ◽  
Pregnant Mouse ◽  
Receptor Subtype ◽  
Hek 293 ◽  
Physiological Regulation ◽  
293 Cells ◽  
Subtype 3

Alternative splicing of ryanodine receptor subtype 3 (RYR3) may generate a short isoform (RYR3S) without channel function and a functional full-length isoform (RYR3L). The RYR3S isoform has been shown to negatively regulate the native RYR2 subtype in smooth muscle cells as well as the RYR3L isoform when both isoforms were coexpressed in HEK-293 cells. Mouse myometrium expresses only the RYR3 subtype, but the role of RYR3 isoforms obtained by alternative splicing and their activation by cADP-ribose during pregnancy have never been investigated. Here, we show that both RYR3S and RYR3L isoforms are differentially expressed in nonpregnant and pregnant mouse myometrium. The use of antisense oligonucleotides directed against each isoform indicated that only RYR3L was activated by caffeine and cADP-ribose in nonpregnant myometrium. These RYR3L-mediated Ca2+ releases were negatively regulated by RYR3S expression. At the end of pregnancy, the relative expression of RYR3L versus RYR3S and its ability to respond to cADP-ribose were increased. Therefore, our results suggest that physiological regulation of RYR3 alternative splicing may play an essential role at the end of pregnancy.

scholarly journals ERK1/2-EGR1-SRSF10 Axis Mediated Alternative Splicing Plays a Critical Role in Head and Neck Cancer

2021 ◽  
Vol 9 ◽  
Author(s):  
Sandhya Yadav ◽  
Deepak Pant ◽  
Atul Samaiya ◽  
Neetu Kalra ◽  
Sanjay Gupta ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Alternative Splicing ◽  
Head And Neck ◽  
Neck Cancer ◽  
Splice Variants ◽  
Critical Role ◽  
Splicing Factor ◽  
Binding Motif ◽  
Cancer Pathogenesis

Aberrant alternative splicing is recognized to promote cancer pathogenesis, but the underlying mechanism is yet to be clear. Here, in this study, we report the frequent upregulation of SRSF10 (serine and arginine-rich splicing factor 10), a member of an expanded family of SR splicing factors, in the head and neck cancer (HNC) patients sample in comparison to paired normal tissues. We observed that SRSF10 plays a crucial role in HNC tumorigenesis by affecting the pro-death, pro-survical splice variants of BCL2L1 (BCL2 Like 1: BCLx: Apoptosis Regulator) and the two splice variants of PKM (Pyruvate kinase M), PKM1 normal isoform to PKM2 cancer-specific isoform. SRSF10 is a unique splicing factor with a similar domain organization to that of SR proteins but functions differently as it acts as a sequence-specific splicing activator in its phosphorylated form. Although a body of research studied the role of SRSF10 in the splicing process, the regulatory mechanisms underlying SRSF10 upregulation in the tumor are not very clear. In this study, we aim to dissect the pathway that regulates the SRSF10 upregulation in HNC. Our results uncover the role of transcription factor EGR1 (Early Growth Response1) in elevating the SRSF10 expression; EGR1 binds to the promoter of SRSF10 and promotes TET1 binding leading to the CpG demethylation (hydroxymethylation) in the adjacent position of the EGR1 binding motif, which thereby instigate SRSF10 expression in HNC. Interestingly we also observed that the EGR1 level is in the sink with the ERK1/2 pathway, and therefore, inhibition of the ERK1/2 pathway leads to the decreased EGR1 and SRSF10 expression level. Together, this is the first report to the best of our knowledge where we characterize the ERK 1/2-EGR1-SRSF10 axis regulating the cancer-specific splicing, which plays a critical role in HNC and could be a therapeutic target for better management of HNC patients.

scholarly journals Compounds from Cynomorium songaricum with Estrogenic and Androgenic Activities Suppress the Oestrogen/Androgen-Induced BPH Process

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Xueni Wang ◽  
Rui Tao ◽  
Jing Yang ◽  
Lin Miao ◽  
Yu Wang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Transcriptional Activity ◽  
Nuclear Translocation ◽  
Immunofluorescence Assay ◽  
Luciferase Reporter ◽  
Reporter Assay ◽  
Lncap Cells ◽  
Mcf 7

Objective. To investigate the phytoestrogenic and phytoandrogenic activities of compounds isolated from CS and uncover the role of CS in prevention of oestrogen/androgen-induced BPH. Methods. Cells were treated with CS compounds, and immunofluorescence assay was performed to detect the nuclear translocation of ERα or AR in MCF-7 or LNCaP cells; luciferase reporter assay was performed to detect ERs or AR transcriptional activity in HeLa or AD293 cells; MTT assay was performed to detect the cell proliferation of MCF-7 or LNCaP cells. Oestrogen/androgen-induced BPH model was established in rat and the anti-BPH, anti-estrogenic, and anti-androgenic activities of CS in vivo were further investigated. Results. The nuclear translocation of ERα was stimulated by nine CS compounds, three of which also stimulated AR translocation. The transcriptional activities of ERα and ERβ were induced by five compounds, within which only ECG induced AR transcriptional activity as well. Besides, ECG stimulated the proliferation of both MCF-7 cells and LNCaP cells. CS extract suppressed oestrogen/androgen-induced BPH progress in vivo by downregulation of E2 and T level in serum and alteration of the expressions of ERα, ERβ, and AR in the prostate. Conclusion. Our data demonstrates that compounds from CS exhibit phytoestrogenic and phytoandrogenic activities, which may contribute to inhibiting the oestrogen/androgen-induced BPH development.

scholarly journals Alternative splicing of auxiliary β2-subunits stabilizes Cav2.3 Ca2+ channel activity in continuously active midbrain dopamine neurons

2021 ◽  
Author(s):  
Anita Siller ◽  
Nadja T. Hofer ◽  
Giulia Tomagra ◽  
Nicole Wiederspohn ◽  
Simon Hess ◽  
...  
Keyword(s):  
Alternative Splicing ◽  
Splice Variants ◽  
Brain Slices ◽  
Physiological Role ◽  
Neuronal Firing ◽  
Dopamine Neurons ◽  
Channel Activity ◽  
Channel Inactivation ◽  
Midbrain Dopamine

AbstractIn dopaminergic (DA) substantia nigra (SN) neurons Cav2.3 R-type Ca2+-currents contribute to somatodendritic Ca2+-oscillations. These may contribute to the selective degeneration of these neurons in Parkinson’s disease (PD) since Cav2.3-knockout is neuroprotective in a PD mouse model. However, the typical Cav2.3 gating would predict complete channel inactivation during SN DA neuronal firing. Here we show that in tsA-201-cells the membrane-anchored β2-splice variants β2a and β2e stabilize Cav2.3 gating properties allowing sustained Cav2.3 availability during simulated pacemaking and enhanced Ca2+-currents during bursts. We confirmed the expression of β2a and β2e-subunits in the SN and identified SN DA neurons. Patch-clamp recordings of SN DA neurons in mouse brain slices revealed R-type Ca2+-currents similar to β2a- or β2e-stabilized Cav2.3-currents and recordings in cultured murine DA neurons confirmed their activity during pacemaking. Taken together, our data support an important (patho)physiological role of β-subunit alternative splicing for Cav2.3 Ca2+-signaling in highly vulnerable SN DA neurons.

Oct1 regulates cell growth of LNCaP cells and is a prognostic factor for prostate cancer

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Prostate Cancer ◽  
Prognostic Factor ◽  
Hazard Analysis ◽  
Critical Role ◽  
Immunohistochemical Analysis ◽  
Lncap Cells ◽  
Cancer Specific Survival ◽  
High Gleason Score ◽  
Castrate Resistant ◽  
Transcription Factor 1

The androgen receptor (AR) plays a critical role in the development and the progression of prostate cancer. Alterations in theexpression of AR coregulators lead to AR hypersensitivity, which is one of the mechanisms underlying the progression ofprostate cancer into a castrate-resistant state. Octamer transcription factor 1 (Oct1) is a ubiquitous member of the POUhomeodomainfamily that functions as a coregulator of AR. In our study, the contribution of Oct1 to prostate cancerdevelopment was examined. Immunocytochemistry analysis showed that Oct1 is expressed in the nuclei of LNCaP cells.siRNA-mediated silencing of Oct1 expression inhibited LNCaP cell proliferation. Immunohistochemical analysis of Oct1expression in tumor specimens obtained from 102 patients with prostate cancer showed a positive correlation of Oct1immunoreactivity with a high Gleason score and AR immunoreactivity (p 5 0.0042 and p < 0.0001, respectively). Moreover,patients with high immunoreactivity of Oct1 showed a low cancer-specific survival rate, and those patients with highimmunoreactivities of both Oct1 and AR exhibited poorer cancer-specific prognosis. Multivariate hazard analysis revealed asignificant correlation between high Oct1 immunoreactivity and poor cancer-specific survival (p 5 0.012). These resultsdemonstrate that Oct1 can be a prognostic factor in prostate cancer as a coregulator of AR and may lead to the developmentof a new therapeutic intervention for prostate cancer.

scholarly journals PPM1G promotes the progression of hepatocellular carcinoma via phosphorylation regulation of alternative splicing protein SRSF3

2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Dawei Chen ◽  
Zhenguo Zhao ◽  
Lu Chen ◽  
Qinghua Li ◽  
Jixue Zou ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Alternative Splicing ◽  
Protein Function ◽  
Vital Role ◽  
Normal Tissues ◽  
Mechanistic Analysis ◽  
Highly Correlated ◽  
Splicing Patterns

AbstractEmerging evidence has demonstrated that alternative splicing has a vital role in regulating protein function, but how alternative splicing factors can be regulated remains unclear. We showed that the PPM1G, a protein phosphatase, regulated the phosphorylation of SRSF3 in hepatocellular carcinoma (HCC) and contributed to the proliferation, invasion, and metastasis of HCC. PPM1G was highly expressed in HCC tissues compared to adjacent normal tissues, and higher levels of PPM1G were observed in adverse staged HCCs. The higher levels of PPM1G were highly correlated with poor prognosis, which was further validated in the TCGA cohort. The knockdown of PPM1G inhibited the cell growth and invasion of HCC cell lines. Further studies showed that the knockdown of PPM1G inhibited tumor growth in vivo. The mechanistic analysis showed that the PPM1G interacted with proteins related to alternative splicing, including SRSF3. Overexpression of PPM1G promoted the dephosphorylation of SRSF3 and changed the alternative splicing patterns of genes related to the cell cycle, the transcriptional regulation in HCC cells. In addition, we also demonstrated that the promoter of PPM1G was activated by multiple transcription factors and co-activators, including MYC/MAX and EP300, MED1, and ELF1. Our study highlighted the essential role of PPM1G in HCC and shed new light on unveiling the regulation of alternative splicing in malignant transformation.

scholarly journals LncRNA CRNDE attenuates chemoresistance in gastric cancer via SRSF6-regulated alternative splicing of PICALM

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Feifei Zhang ◽  
Hui Wang ◽  
Jiang Yu ◽  
Xueqing Yao ◽  
Shibin Yang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Alternative Splicing ◽  
Noncoding Rna ◽  
De Novo ◽  
Acquired Resistance ◽  
Genetic Alterations ◽  
Clinical Samples ◽  
Autophagy Flux ◽  
Resistance To Chemotherapy

AbstractDe novo and acquired resistance, which are mainly mediated by genetic alterations, are barriers to effective routine chemotherapy. However, the mechanisms underlying gastric cancer (GC) resistance to chemotherapy are still unclear. We showed that the long noncoding RNA CRNDE was related to the chemosensitivity of GC in clinical samples and a PDX model. CRNDE was decreased and inhibited autophagy flux in chemoresistant GC cells. CRNDE directly bound to splicing protein SRSF6 to reduce its protein stability and thus regulate alternative splicing (AS) events. We determined that SRSF6 regulated the PICALM exon 14 skip splice variant and triggered a significant S-to-L isoform switch, which contributed to the expression of the long isoform of PICALM (encoding PICALML). Collectively, our findings reveal the key role of CRNDE in autophagy regulation, highlighting the significance of CRNDE as a potential prognostic marker and therapeutic target against chemoresistance in GC.

scholarly journals Microbiomes attached to fresh perennial ryegrass are temporally resilient and adapt to changing ecological niches

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sharon A. Huws ◽  
Joan E. Edwards ◽  
Wanchang Lin ◽  
Francesco Rubino ◽  
Mark Alston ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Perennial Ryegrass ◽  
Transcriptional Activity ◽  
Ecological Niches ◽  
Ecological Interactions ◽  
Carbohydrate Degradation ◽  
Host Nutrition ◽  
Role Based ◽  
Insight Into

Abstract Background Gut microbiomes, such as the rumen, greatly influence host nutrition due to their feed energy-harvesting capacity. We investigated temporal ecological interactions facilitating energy harvesting at the fresh perennial ryegrass (PRG)-biofilm interface in the rumen using an in sacco approach and prokaryotic metatranscriptomic profiling. Results Network analysis identified two distinct sub-microbiomes primarily representing primary (≤ 4 h) and secondary (≥ 4 h) colonisation phases and the most transcriptionally active bacterial families (i.e Fibrobacteriaceae, Selemondaceae and Methanobacteriaceae) did not interact with either sub-microbiome, indicating non-cooperative behaviour. Conversely, Prevotellaceae had most transcriptional activity within the primary sub-microbiome (focussed on protein metabolism) and Lachnospiraceae within the secondary sub-microbiome (focussed on carbohydrate degradation). Putative keystone taxa, with low transcriptional activity, were identified within both sub-microbiomes, highlighting the important synergistic role of minor bacterial families; however, we hypothesise that they may be ‘cheating’ in order to capitalise on the energy-harvesting capacity of other microbes. In terms of chemical cues underlying transition from primary to secondary colonisation phases, we suggest that AI-2-based quorum sensing plays a role, based on LuxS gene expression data, coupled with changes in PRG chemistry. Conclusions In summary, we show that fresh PRG-attached prokaryotes are resilient and adapt quickly to changing niches. This study provides the first major insight into the complex temporal ecological interactions occurring at the plant-biofilm interface within the rumen. The study also provides valuable insights into potential plant breeding strategies for development of the utopian plant, allowing optimal sustainable production of ruminants.

scholarly journals Role of Alternative Splicing in Regulating Host Response to Viral Infection

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1720
Author(s):  
Kuo-Chieh Liao ◽  
Mariano A. Garcia-Blanco
Keyword(s):  
Innate Immunity ◽  
Alternative Splicing ◽  
Immune Responses ◽  
Viral Infection ◽  
Rna Splicing ◽  
Type I ◽  
Host Immune Responses ◽  
Transcriptional Regulatory Mechanisms ◽  
Host Virus Interactions

The importance of transcriptional regulation of host genes in innate immunity against viral infection has been widely recognized. More recently, post-transcriptional regulatory mechanisms have gained appreciation as an additional and important layer of regulation to fine-tune host immune responses. Here, we review the functional significance of alternative splicing in innate immune responses to viral infection. We describe how several central components of the Type I and III interferon pathways encode spliced isoforms to regulate IFN activation and function. Additionally, the functional roles of splicing factors and modulators in antiviral immunity are discussed. Lastly, we discuss how cell death pathways are regulated by alternative splicing as well as the potential role of this regulation on host immunity and viral infection. Altogether, these studies highlight the importance of RNA splicing in regulating host–virus interactions and suggest a role in downregulating antiviral innate immunity; this may be critical to prevent pathological inflammation.

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