scholarly journals Targeting BRF2 in Cancer with Repurposed Drugs Using in Silico Methods

2020 ◽  
Author(s):  
Behnam Rashidieh ◽  
Maryam Molakarimi ◽  
Ammar Mohseni ◽  
Hein Truong ◽  
Sriganesh Srihari ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Binding Capacity ◽  
Rna Polymerase Iii ◽  
Lung Squamous Cell Carcinoma ◽  
Dynamics Simulation ◽  
Optimal Drug ◽  
Redox Sensing ◽  
Repurposed Drugs ◽  
Induced Apoptosis ◽  
Dna Complex

Overexpression of BRF2, the essential subunit of RNA polymerase III, is required for the development of a variety of cancers, including lung squamous cell carcinoma and breast cancer. BRF2 also acts as a central redox-sensing transcription factor (TF) and is involved in the regulation of oxidative stress (OS) pathway where its amplification enables cancer cells to evade OS-induced apoptosis. Here, we experimentally confirmed a link between BRF2 and DNA damage response (DDR) signaling. Focusing on its DNA binding capacity, we targeted BRF2-TATA binding Protein (TBP)-DNA complex interaction to functionally inhibit this transcription factor (TF). We found that BRF2 binding to TBP changes the conformation of this protein and therefore characterized these events in detail. Virtual screening allowed selection of the optimal drug based on binding energy, and intermolecular, internal, and torsional energy parameters. Molecular dynamics simulation confirmed the docking results and all simulations were validated by root‐mean‐square deviation (RMSD). According to the simulation, the chosen drug was efficacious in targeting BRF2 which therefore requires further experimental validation to investigate the effect of this drug on BRF2 functions and its downstream pathways.

scholarly journals Targeting BRF2 in Cancer Using Repurposed Drugs

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3778
Author(s):  
Behnam Rashidieh ◽  
Maryam Molakarimi ◽  
Ammar Mohseni ◽  
Simon Manuel Tria ◽  
Hein Truong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Dna Damage Response ◽  
Cellular Proliferation ◽  
Rna Polymerase Iii ◽  
Lung Squamous Cell Carcinoma ◽  
Dynamics Simulation ◽  
Drug Candidates ◽  
Damage Response ◽  
Induced Apoptosis

The overexpression of BRF2, a selective subunit of RNA polymerase III, has been shown to be crucial in the development of several types of cancers, including breast cancer and lung squamous cell carcinoma. Predominantly, BRF2 acts as a central redox-sensing transcription factor (TF) and is involved in rescuing oxidative stress (OS)-induced apoptosis. Here, we showed a novel link between BRF2 and the DNA damage response. Due to the lack of BRF2-specific inhibitors, through virtual screening and molecular dynamics simulation, we identified potential drug candidates that interfere with BRF2-TATA-binding Protein (TBP)-DNA complex interactions based on binding energy, intermolecular, and torsional energy parameters. We experimentally tested bexarotene as a potential BRF2 inhibitor. We found that bexarotene (Bex) treatment resulted in a dramatic decline in oxidative stress and Tert-butylhydroquinone (tBHQ)-induced levels of BRF2 and consequently led to a decrease in the cellular proliferation of cancer cells which may in part be due to the drug pretreatment-induced reduction of ROS generated by the oxidizing agent. Our data thus provide the first experimental evidence that BRF2 is a novel player in the DNA damage response pathway and that bexarotene can be used as a potential inhibitor to treat cancers with the specific elevation of oxidative stress.

scholarly journals Targeting BRF2 in Cancer Using Repurposed Drugs

2021 ◽  
Author(s):  
Behnam Rashidieh ◽  
Maryam Molakarimi ◽  
Ammar Mohseni ◽  
Simon Tria ◽  
Sriganesh Srihari ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Dna Damage Response ◽  
Cellular Proliferation ◽  
Rna Polymerase Iii ◽  
Lung Squamous Cell Carcinoma ◽  
Drug Candidates ◽  
Dramatic Decline ◽  
Damage Response ◽  
Induced Apoptosis

Overexpression of BRF2, a selective subunit of RNA polymerase III, has been shown to be crucial in the development of several types of cancers, including breast cancer and lung squamous cell carcinoma . Predominately, BRF2 acts as a central redox-sensing transcription factor (TF) and is involved in rescuing oxidative stress (OS) -induced apoptosis. Here, we showed a novel link between BRF2 and DNA damage response. Due to the lack of BRF2 specific inhibitors, through virtual and molecular dynamics screening, we identified potential drug candidates that interfere with BRF2-TATA-binding Protein (TBP)-DNA complex interactions based on binding energy, intermolecular, and torsional energy parameters. We experimentally tested Bexarotene as a potential BRF2 inhibitor. We found that Bexarotene (Bex) treatment resulted in a dramatic decline in oxidative stress (Tert-butylhydroquinone (tBHQ))-induced levels of BRF2 and consequently, lead to a decrease in cellular proliferation of cancer cells which may in part be due to drug pretreatment induced reduction of ROS generated by the oxidizing agent. Our data thus, provide the first experimental evidence that BRF2 is a novel player in DNA damage response pathway and Bexarotene can be used as a potential inhibitor to treat cancers with the specific elevation of oxidative stress.

scholarly journals Functional dissection of the B" component of RNA polymerase III transcription factor IIIB: a scaffolding protein with multiple roles in assembly and initiation of transcription.

1997 ◽  
Vol 17 (4) ◽  
pp. 1868-1880 ◽  
Author(s):  
A Kumar ◽  
G A Kassavetis ◽  
E P Geiduschek ◽  
M Hambalko ◽  
C J Brent
Keyword(s):  
Transcription Factor ◽  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
Dna Complexes ◽  
Protein Footprinting ◽  
U6 Snrna ◽  
Polymerase Iii ◽  
Core Proteins ◽  
Transcription Factor Iiib ◽  
Dna Complex

Transcription factor IIIB (TFIIIB), the central transcription factor of Saccharomyces cerevisiae RNA polymerase III, is composed of TATA-binding protein, the TFIIB-related protein Brf, and B". B", the last component to enter the TFIIIB-DNA complex, confers extremely tight DNA binding on TFIIIB. Terminally and internally deleted B" derivatives were tested for competence to form TFIIIB-DNA complexes by TFIIIC-dependent and -independent pathways on the SUP4 tRNA(Tyr) and U6 snRNA (SNR6) genes, respectively, and for transcription. Selected TFIIIB-TFIIIC-DNA complexes assembled with truncated B" were analyzed by DNase I footprinting, and the surface topography of B" in the TFIIIB-DNA complex was also analyzed by hydroxyl radical protein footprinting. These analyses define functional domains of B" and also reveal roles in start site selection by RNA polymerase III and in clearing TFIIIC from the transcriptional start. Although absolutely required for transcription, B" can be extensively truncated. Core proteins retaining as few as 176 (of 594) amino acids remain competent to transcribe the SNR6 gene in vitro. TFIIIC-dependent assembly on DNA and transcription requires a larger core of B": two domains (I and II) that are required for SNR6 transcription on an either-or basis are simultaneously required for TFIIIC-dependent assembly of DNA complexes and transcription. Domains I and II of B" are buried upon assembly of the TFIIIB-DNA complex, as determined by protein footprinting. The picture of the TFIIIB-DNA complex that emerges is that B" serves as its scaffold and is folded over in the complex so that domains I and II are near one another.

scholarly journals Suppression of E1A-Mediated Transformation by the p50E4F Transcription Factor

1999 ◽  
Vol 19 (7) ◽  
pp. 4739-4749 ◽  
Author(s):  
Elma R. Fernandes ◽  
Robert J. Rooney
Keyword(s):  
Cell Death ◽  
Transcription Factor ◽  
Suppressive Effect ◽  
Culture Conditions ◽  
Binding Activity ◽  
Cellular Transcription Factor ◽  
Dna Binding Activity ◽  
3T3 Fibroblasts ◽  
Induced Apoptosis ◽  
Nih 3T3

ABSTRACT The adenovirus E1A gene can act as an oncogene or a tumor suppressor, with the latter effect generally arising from the induction of apoptosis or the repression of genes that provide oncogenic growth stimuli (e.g., HER-2/c-erbB2/neu) or increased metastatic invasiveness (e.g., metalloproteases). In this study, coexpression of E1A and p50E4F, a cellular transcription factor whose DNA binding activity is stimulated by E1A, suppressed colony formation by NIH 3T3 cells and transformation of primary rat embryo fibroblasts but had no observed effect in the absence of E1A. Domains in p50E4F required for stimulation of the adenovirus E4 promoter were required for the suppressive effect, indicating a transcriptional mechanism. In serum-containing media, retroviral expression of p50E4F in E1A13S/ras-transformed NIH 3T3 fibroblasts had little effect on subconfluent cultures but accelerated a decline in viability after the cultures reached confluence. Cell death occurred by both apoptosis and necrosis, with the predominance of each process determined by culture conditions. In serum-free media, p50E4F accelerated E1A-induced apoptosis. The results suggest that p50E4F sensitizes cells to signals or conditions that cause cell death.

Transcription factor 3 controls cell proliferation and migration in glioblastoma multiforme cell lines

2016 ◽  
Vol 94 (3) ◽  
pp. 247-255 ◽  
Author(s):  
Ruiting Li ◽  
Yinghui Li ◽  
Xin Hu ◽  
Haiwei Lian ◽  
Lei Wang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Glioblastoma Multiforme ◽  
Cell Lines ◽  
Normal Brain ◽  
Phosphatidylinositol 3 Kinase ◽  
T Cell Factor ◽  
And Migration ◽  
Induced Apoptosis ◽  
Proliferation And Migration ◽  
Transcription Factor 3

Transcription factor 3 (TCF3) is a member of the T-cell factor/lymphoid enhancer factor (TCF/LEF) transcription factor family. Recent studies have demonstrated its potential carcinogenic properties. Here we show that TCF3 was upregulated in glioma tissues compared with normal brain tissues. This upregulation of the TCF3 gene probably has functional significance in brain-tumor progression. Our studies on glioblastoma multiforme (GBM) cell lines show that knock-down of TCF3 induced apoptosis and inhibited cell migration. Further analysis revealed that down-regulation of TCF3 gene expression inhibits Akt and Erk1/2 activation, suggesting that the carcinogenic properties of TCF3 in GBM are partially mediated by the phosphatidylinositol 3-kinase–Akt and MAPK–Erk signaling pathways. Considered together, the results of this study demonstrate that high levels of TCF3 in gliomas potentially promote glioma development through the Akt and Erk pathways.

scholarly journals Involvement of RNA Polymerase III in Immune Responses

2015 ◽  
Vol 35 (10) ◽  
pp. 1848-1859 ◽  
Author(s):  
Damian Graczyk ◽  
Robert J. White ◽  
Kevin M. Ryan
Keyword(s):  
Transcription Factor ◽  
Immune Responses ◽  
Rna Polymerase ◽  
Rna Polymerase Iii ◽  
Trna Genes ◽  
Malignant Cells ◽  
Polymerase Iii ◽  
Mouse Macrophages ◽  
Tightly Coupled ◽  
Pol Iii

Inflammation in the tumor microenvironment has many tumor-promoting effects. In particular, tumor-associated macrophages (TAMs) produce many cytokines which can support tumor growth by promoting survival of malignant cells, angiogenesis, and metastasis. Enhanced cytokine production by TAMs is tightly coupled with protein synthesis. In turn, translation of proteins depends on tRNAs, short abundant transcripts that are made by RNA polymerase III (Pol III). Here, we connect these facts by showing that stimulation of mouse macrophages with lipopolysaccharides (LPS) from the bacterial cell wall causes transcriptional upregulation of tRNA genes. The transcription factor NF-κB is a key transcription factor mediating inflammatory signals, and we report that LPS treatment causes an increased association of the NF-κB subunit p65 with tRNA genes. In addition, we show that p65 can directly associate with the Pol III transcription factor TFIIIB and that overexpression of p65 induces Pol III-dependent transcription. As a consequence of these effects, we show that inhibition of Pol III activity in macrophages restrains cytokine secretion and suppresses phagocytosis, two key functional characteristics of these cells. These findings therefore identify a radical new function for Pol III in the regulation of macrophage function which may be important for the immune responses associated with both normal and malignant cells.

Sign in / Sign up

Export Citation Format

Share Document