SUMO Modification of PAF1/PD2 Enables PML Interaction and Promotes Radiation Resistance in Pancreatic Ductal Adenocarcinoma

2021 ◽  
Author(s):  
Sanchita Rauth ◽  
Saswati Karmakar ◽  
Ashu Shah ◽  
Parthasarathy Seshacharyulu ◽  
Rama Krishna Nimmakayala ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Rna Polymerase Ii ◽  
Radiation Resistance ◽  
Radiation Treatment ◽  
Site Directed Mutagenesis ◽  
Ductal Adenocarcinoma ◽  
Transcriptional Elongation ◽  
Post Translational Modification ◽  
Pancreatic Cancer Cells

RNA polymerase II-associated factor 1 (PAF1)/pancreatic differentiation 2 (PD2) is a core subunit of the human PAF1 complex (PAF1C) that regulates the RNA polymerase II function during transcriptional elongation. PAF1/PD2 has also been linked to the oncogenesis of pancreatic ductal adenocarcinoma (PDAC). Here, we report that PAF1/PD2 undergoes post-translational modification (PTM) through SUMOylation, enhancing the radiation resistance of PDAC cells. We identified that PAF1/PD2 is preferentially modified by small ubiquitin-related modifier 1 (SUMO 1), and mutating the residues (K)-150 and 154 by site-directed mutagenesis reduces the SUMOylation. Interestingly, PAF1/PD2 was found to directly interact with the promyelocytic leukemia (PML) protein in response to radiation and inhibiton of PAF1/PD2 SUMOylation at K-150/154 affects its interaction with PML. Our results demonstrate that SUMOylation of PAF1/PD2 increased in the radiated pancreatic cancer cells. Further, inhibition of SUMOylation or PML reduces the cell growth and proliferation of PDAC cells after radiation treatment. These results suggest that SUMOylation of PAF1/PD2 interacts with PTM for PDAC cell survival. Furthermore, abolishing the SUMOylation in PDAC cells enhances the effectiveness of radiotherapy. Overall, our results demonstrate a novel PTM and PAF1/PD2 interaction through SUMOylation and inhibiting the SUMOylation of PAF1/PD2 enhance the therapeutic efficacy for PDAC.

scholarly journals Tumor-derived exosomal long noncoding RNA LINC01133, regulated by Periostin, contributes to pancreatic ductal adenocarcinoma epithelial-mesenchymal transition through the Wnt/β-catenin pathway by silencing AXIN2

Oncogene ◽  
2021 ◽  
Vol 40 (17) ◽  
pp. 3164-3179
Author(s):  
Yang Liu ◽  
Tianchi Tang ◽  
Xiaosheng Yang ◽  
Peng Qin ◽  
Pusen Wang ◽  
...  
Keyword(s):  
Pancreatic Ductal Adenocarcinoma ◽  
Noncoding Rna ◽  
Pancreatic Tumor ◽  
Epithelial Mesenchymal Transition ◽  
Noncoding Rnas ◽  
Ductal Adenocarcinoma ◽  
Overall Survival Rate ◽  
Poor Overall Survival ◽  
Mesenchymal Transition ◽  
Pancreatic Cancer Cells

AbstractPancreatic ductal adenocarcinoma (PDAC) is one of the most fatal malignancies and rapidly progressive diseases. Exosomes and long noncoding RNAs (lncRNAs) are emerging as vital mediators in tumor cells and their microenvironment. However, the detailed roles and mechanisms of exosomal lncRNAs in PDAC progression remain unknown. Here, we aimed to clarify the clinical significance and mechanisms of exosomal lncRNA 01133 (LINC01133) in PDAC. We analyzed the expression of LINC01133 in PDAC and found that exosomal LINC01133 expression was high and positively correlated with higher TNM stage and poor overall survival rate of PDAC patients. Further research demonstrated that Periostin could increase exosome secretion and then enhance LINC01133 expression. In addition, Periostin increased p-EGFR, p-Erk, and c-myc expression, and c-myc could bind to the LINC01133 promoter region. These findings suggested that LINC01133 can be regulated by Periostin via EGFR pathway activity. We also observed that LINC01133 promoted the proliferation, migration, invasion, and epithelial–mesenchymal transition (EMT) of pancreatic cancer cells. We subsequently evaluated the effect of LINC01133 on the Wnt/β-catenin pathway and confirmed that LINC01133 can interact with Enhancer Of Zeste Homolog 2 (EZH2) and then promote H3K27 trimethylation. This can further silence AXIN2 and suppress GSK3 activity, ultimately activating β-catenin. Collectively, these data indicate that exosomal LINC01133 plays an important role in pancreatic tumor progression, and targeting LINC01133 may provide a potential treatment strategy for PDAC.

Identification of rpo30, a vaccinia virus RNA polymerase gene with structural similarity to a eucaryotic transcription elongation factor

1990 ◽  
Vol 10 (10) ◽  
pp. 5433-5441
Author(s):  
B Y Ahn ◽  
P D Gershon ◽  
E V Jones ◽  
B Moss
Keyword(s):  
Rna Polymerase ◽  
Vaccinia Virus ◽  
Rna Polymerase Ii ◽  
Elongation Factor ◽  
Viral Rna ◽  
In Vitro Translation ◽  
Virus Protein ◽  
Transcriptional Elongation

Eucaryotic transcription factors that stimulate RNA polymerase II by increasing the efficiency of elongation of specifically or randomly initiated RNA chains have been isolated and characterized. We have identified a 30-kilodalton (kDa) vaccinia virus-encoded protein with apparent homology to SII, a 34-kDa mammalian transcriptional elongation factor. In addition to amino acid sequence similarities, both proteins contain C-terminal putative zinc finger domains. Identification of the gene, rpo30, encoding the vaccinia virus protein was achieved by using antibody to the purified viral RNA polymerase for immunoprecipitation of the in vitro translation products of in vivo-synthesized early mRNA selected by hybridization to cloned DNA fragments of the viral genome. Western immunoblot analysis using antiserum made to the vaccinia rpo30 protein expressed in bacteria indicated that the 30-kDa protein remains associated with highly purified viral RNA polymerase. Thus, the vaccinia virus protein, unlike its eucaryotic homolog, is an integral RNA polymerase subunit rather than a readily separable transcription factor. Further studies showed that the expression of rpo30 is regulated by dual early and later promoters.

scholarly journals The Emerging Role of Cyclin-Dependent Kinases (CDKs) in Pancreatic Ductal Adenocarcinoma

2018 ◽  
Vol 19 (10) ◽  
pp. 3219 ◽  
Author(s):  
Balbina García-Reyes ◽  
Anna-Laura Kretz ◽  
Jan-Philipp Ruff ◽  
Silvia von Karstedt ◽  
Andreas Hillenbrand ◽  
...  
Keyword(s):  
Pancreatic Ductal Adenocarcinoma ◽  
Therapeutic Potential ◽  
Current Knowledge ◽  
Ductal Adenocarcinoma ◽  
Transcriptional Elongation ◽  
Cyclin Dependent Kinases ◽  
Dismal Prognosis ◽  
The Family ◽  
Cycle Regulation

The family of cyclin-dependent kinases (CDKs) has critical functions in cell cycle regulation and controlling of transcriptional elongation. Moreover, dysregulated CDKs have been linked to cancer initiation and progression. Pharmacological CDK inhibition has recently emerged as a novel and promising approach in cancer therapy. This idea is of particular interest to combat pancreatic ductal adenocarcinoma (PDAC), a cancer entity with a dismal prognosis which is owed mainly to PDAC’s resistance to conventional therapies. Here, we review the current knowledge of CDK biology, its role in cancer and the therapeutic potential to target CDKs as a novel treatment strategy for PDAC.

scholarly journals Amino Acid Substitutions in Yeast TFIIF Confer Upstream Shifts in Transcription Initiation and Altered Interaction with RNA Polymerase II

2004 ◽  
Vol 24 (24) ◽  
pp. 10975-10985 ◽  
Author(s):  
Mohamed A. Ghazy ◽  
Seth A. Brodie ◽  
Michelle L. Ammerman ◽  
Lynn M. Ziegler ◽  
Alfred S. Ponticelli
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcription Initiation ◽  
Primer Extension ◽  
Site Directed Mutagenesis ◽  
Protein Encoding ◽  
Transcription Factor Iif ◽  
Growth Properties ◽  
Encoding Genes

ABSTRACT Transcription factor IIF (TFIIF) is required for transcription of protein-encoding genes by eukaryotic RNA polymerase II. In contrast to numerous studies establishing a role for higher eukaryotic TFIIF in multiple steps of the transcription cycle, relatively little has been reported regarding the functions of TFIIF in the yeast Saccharomyces cerevisiae. In this study, site-directed mutagenesis, plasmid shuffle complementation assays, and primer extension analyses were employed to probe the functional domains of the S. cerevisiae TFIIF subunits Tfg1 and Tfg2. Analyses of 35 Tfg1 alanine substitution mutants and 19 Tfg2 substitution mutants identified 5 mutants exhibiting altered properties in vivo. Primer extension analyses revealed that the conditional growth properties exhibited by the tfg1-E346A, tfg1-W350A, and tfg2-L59K mutants were associated with pronounced upstream shifts in transcription initiation in vivo. Analyses of double mutant strains demonstrated functional interactions between the Tfg1 mutations and mutations in Tfg2, TFIIB, and RNA polymerase II. Importantly, biochemical results demonstrated an altered interaction between mutant TFIIF protein and RNA polymerase II. These results provide direct evidence for the involvement of S. cerevisiae TFIIF in the mechanism of transcription start site utilization and support the view that a TFIIF-RNA polymerase II interaction is a determinant in this process.

scholarly journals Mechanism and regulation of transcriptional elongation by RNA polymerase II

1999 ◽  
Vol 11 (3) ◽  
pp. 342-346 ◽  
Author(s):  
Daniel Reines ◽  
Ronald C Conaway ◽  
Joan Weliky Conaway
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcriptional Elongation

scholarly journals GSK-3 is an RNA polymerase II phospho-CTD kinase

2020 ◽  
Vol 48 (11) ◽  
pp. 6068-6080 ◽  
Author(s):  
Nicolás Nieto Moreno ◽  
Florencia Villafañez ◽  
Luciana E Giono ◽  
Carmen Cuenca ◽  
Gastón Soria ◽  
...  
Keyword(s):  
Dna Damage ◽  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Glycogen Synthase ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Transcriptional Elongation ◽  
Induced Apoptosis ◽  
Carboxy Terminal

Abstract We have previously found that UV-induced DNA damage causes hyperphosphorylation of the carboxy terminal domain (CTD) of RNA polymerase II (RNAPII), inhibition of transcriptional elongation and changes in alternative splicing (AS) due to kinetic coupling between transcription and splicing. In an unbiased search for protein kinases involved in the AS response to DNA damage, we have identified glycogen synthase kinase 3 (GSK-3) as an unforeseen participant. Unlike Cdk9 inhibition, GSK-3 inhibition only prevents CTD hyperphosphorylation triggered by UV but not basal phosphorylation. This effect is not due to differential degradation of the phospho-CTD isoforms and can be reproduced, at the AS level, by overexpression of a kinase-dead GSK-3 dominant negative mutant. GSK-3 inhibition abrogates both the reduction in RNAPII elongation and changes in AS elicited by UV. We show that GSK-3 phosphorylates the CTD in vitro, but preferentially when the substrate is previously phosphorylated, consistently with the requirement of a priming phosphorylation reported for GSK-3 efficacy. In line with a role for GSK-3 in the response to DNA damage, GSK-3 inhibition prevents UV-induced apoptosis. In summary, we uncover a novel role for a widely studied kinase in key steps of eukaryotic transcription and pre-mRNA processing.

scholarly journals BRM270 Inhibits the Proliferation of CD44 Positive Pancreatic Ductal Adenocarcinoma Cells via Downregulation of Sonic Hedgehog Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Do Luong Huynh ◽  
Hyebin Koh ◽  
Nisansala Chandimali ◽  
Jiao Jiao Zhang ◽  
Nameun Kim ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Sonic Hedgehog ◽  
Hedgehog Signaling ◽  
Ductal Adenocarcinoma ◽  
Cell Phenotype ◽  
Sonic Hedgehog Signaling ◽  
Mesenchymal Transition ◽  
Pancreatic Cancer Cells ◽  
Adenocarcinoma Cells

Pancreatic cancer has a poor survival rate as compared to other types of cancer. Surface marker CD44 plays important role in epithelial-mesenchymal transition and cancer stem cell phenotype. Therefore, targeting CD44 positive pancreatic cancer cells might enhance therapies effectiveness. Our previous studies indicated the antitumorigenesis effect of BRM270 in osteosarcoma, lung cancer, and glioblastoma; however there is no evidence on BRM270 impacts on pancreatic cancer growth. In this study, we investigated the effect of BRM270 on the isolated CD44 positive pancreatic ductal adenocarcinoma cells (CD44+PDAC). Results showed that CD44 positive cells undergo apoptosis induced by BRM270. Moreover, BRM270 also inhibits stemness and metastasis traits in CD44+PDAC via Sonic hedgehog signaling pathway and SALL4 expression.In vivostudy indicated that tumor growth derived from CD44+PDAC was suppressed as daily uptake by BRM270 5 mg/kg. These data suggest the alternative approach in antipancreatic tumorigenesis via herbal plants extract and selectively targeting CD44+PDAC cells in tumor.

scholarly journals Aspartate β-hydroxylase promotes pancreatic ductal adenocarcinoma metastasis through activation of SRC signaling pathway

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Kosuke Ogawa ◽  
Qiushi Lin ◽  
Le Li ◽  
Xuewei Bai ◽  
Xuesong Chen ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Stem Cell Marker ◽  
Ductal Adenocarcinoma ◽  
Physical Interaction ◽  
Pancreatic Cancer Cells ◽  
Ecm Degradation ◽  
Invadopodia Formation ◽  
Pdx Models

Abstract Background Signaling pathways critical for embryonic development re-emerge in adult pancreas during tumorigenesis. Aspartate β-hydroxylase (ASPH) drives embryonic cell motility/invasion in pancreatic development/differentiation. We explored if dysregulated ASPH is critically involved in pancreatic cancer pathogenesis. Methods To demonstrate if/how ASPH mediates malignant phenotypes, proliferation, migration, 2-D/3-D invasion, pancreatosphere formation, immunofluorescence, Western blot, co-immunoprecipitation, invadopodia formation/maturation/function, qRT-PCR, immunohistochemistry (IHC), and self-developed in vitro metastasis assays were performed. Patient-derived xenograft (PDX) models of human pancreatic ductal adenocarcinoma (PDAC) were established to illustrate in vivo antitumor effects of the third-generation small molecule inhibitor specifically against ASPH’s β-hydroxylase activity. Prognostic values of ASPH network components were evaluated with Kaplan-Meier plots, log-rank tests, and Cox proportional hazards regression models. Results ASPH renders pancreatic cancer cells more aggressive phenotypes characterized by epithelial–mesenchymal transition (EMT), 2-D/3-D invasion, invadopodia formation/function as demonstrated by extracellular matrix (ECM) degradation, stemness (cancer stem cell marker upregulation and pancreatosphere formation), transendothelial migration (mimicking intravasation/extravasation), and sphere formation (mimicking metastatic colonization/outgrowth at distant sites). Mechanistically, ASPH activates SRC cascade through direct physical interaction with ADAM12/ADAM15 independent of FAK. The ASPH-SRC axis enables invadopodia construction and initiates MMP-mediated ECM degradation/remodeling as executors for invasiveness. Pharmacologic inhibition of invadopodia attenuates in vitro metastasis. ASPH fosters primary tumor development and pulmonary metastasis in PDX models of PDAC, which is blocked by a leading compound specifically against ASPH enzymatic activity. ASPH is silenced in normal pancreas, progressively upregulated from pre-malignant lesions to invasive/advanced stages of PDAC. Expression profiling of ASPH-SRC network components independently/jointly predicts clinical outcome of PDAC patients. Compared to a negative-low level, a moderate-very high level of ASPH, ADAM12, activated SRC, and MMPs correlated with curtailed overall survival (OS) of pancreatic cancer patients (log-rank test, ps < 0.001). The more unfavorable molecules patients carry, the more deleterious prognosis is destinated. Patients with 0–2 (n = 4), 3–5 (n = 8), 6–8 (n = 24), and 9–12 (n = 73) unfavorable expression scores of the 5 molecules had median survival time of 55.4, 15.9, 9.7, and 5.0 months, respectively (p < 0.001). Conclusion Targeting the ASPH-SRC axis, which is essential for propagating multi-step PDAC metastasis, may specifically/substantially retard development/progression and thus improve prognosis of PDAC.

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