A242 THE P2 ISOFORM CLASS OF THE TRANSCRIPTION FACTOR HNF4A PLAYS DNA REPAIR ROLE IN COLORECTAL CANCER

Hepatocyte nuclear factor 4α (HNF4α) is a transcription factor that acts as a master regulator of genes for several endoderm-derived tissues, including the intestine, in which it plays a central role during development and tumorigenesis. To better define the mechanisms by which HNF4α can influence these processes, we identified proteins interacting with HNF4α using stable isotope labelling with amino acids in cell culture (SILAC)-based quantitative proteomics with either immunoprecipitation of green fluorescent protein (GFP) or with proximity-dependent purification by the biotin ligase BirA (BioID), both fused to HNF4α. Surprisingly, these analyses identified a significant enrichment of proteins characterized with a role in DNA repair, a so far unidentified biological feature of this transcription factor. Several of these proteins including PARP1, RAD50, and DNA-PKcs were confirmed to interact with HNF4α in colorectal cancer cell lines. Following DNA damage, HNF4α was able to increase cell viability in colorectal cancer cells. Overall, these observations identify a potential role for this transcription factor during the DNA damage response.

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Platinum Complexes in Colorectal Cancer and Other Solid Tumors

Cancers ◽

10.3390/cancers13092073 ◽

2021 ◽

Vol 13 (9) ◽

pp. 2073

Author(s):

Beate Köberle ◽

Sarah Schoch

Keyword(s):

Colorectal Cancer ◽

Dna Damage ◽

Dna Repair ◽

Cancer Cells ◽

Cisplatin Resistance ◽

Platinum Complexes ◽

Dna Lesions ◽

Dna Damage Signaling ◽

Repair Mechanisms ◽

P53 Inactivation

Cisplatin is one of the most commonly used drugs for the treatment of various solid neoplasms, including testicular, lung, ovarian, head and neck, and bladder cancers. Unfortunately, the therapeutic efficacy of cisplatin against colorectal cancer is poor. Various mechanisms appear to contribute to cisplatin resistance in cancer cells, including reduced drug accumulation, enhanced drug detoxification, modulation of DNA repair mechanisms, and finally alterations in cisplatin DNA damage signaling preventing apoptosis in cancer cells. Regarding colorectal cancer, defects in mismatch repair and altered p53-mediated DNA damage signaling are the main factors controlling the resistance phenotype. In particular, p53 inactivation appears to be associated with chemoresistance and poor prognosis. To overcome resistance in cancers, several strategies can be envisaged. Improved cisplatin analogues, which retain activity in resistant cancer, might be applied. Targeting p53-mediated DNA damage signaling provides another therapeutic strategy to circumvent cisplatin resistance. This review provides an overview on the DNA repair pathways involved in the processing of cisplatin damage and will describe signal transduction from cisplatin DNA lesions, with special attention given to colorectal cancer cells. Furthermore, examples for improved platinum compounds and biochemical modulators of cisplatin DNA damage signaling will be presented in the context of colon cancer therapy.

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Hsa_circ_0026628 promotes the development of colorectal cancer by targeting SP1 to activate the Wnt/β-catenin pathway

Cell Death and Disease ◽

10.1038/s41419-021-03794-6 ◽

2021 ◽

Vol 12 (9) ◽

Author(s):

Xuexiu Zhang ◽

Jianning Yao ◽

Haoling Shi ◽

Bing Gao ◽

Haining Zhou ◽

...

Keyword(s):

Colorectal Cancer ◽

Transcription Factor ◽

Circular Rna ◽

Luciferase Reporter ◽

Circular Rnas ◽

Transcriptional Level ◽

Sp1 Transcription Factor ◽

Reporter Assays ◽

Sphere Formation

AbstractCircular RNAs (circRNAs) have been reported to play crucial roles in the progression of various cancers, including colorectal cancer (CRC). SP1 (Sp1 transcription factor) is a well-recognized oncogene in CRC and is deemed to trigger the Wnt/β-catenin pathway. The present study was designed to investigate the role of circRNAs which shared the same pre-mRNA with SP1 in CRC cells. We identified that hsa_circ_0026628 (circ_0026628), a circular RNA that originated from SP1 pre-mRNA, was upregulated in CRC cells. Sanger sequencing and agarose gel electrophoresis verified the circular characteristic of circ_0026628. Functional assays including CCK-8, colony formation, transwell, immunofluorescence staining, and sphere formation assay revealed the function of circ_0026628. RNA pull-down and mass spectrometry disclosed the proteins interacting with circ_0026628. Mechanistic assays including RIP, RNA pull-down, CoIP, ChIP, and luciferase reporter assays demonstrated the interplays between molecules. The results depicted that circ_0026628 functioned as a contributor to CRC cell proliferation, migration, EMT, and stemness. Mechanistically, circ_0026628 served as the endogenous sponge of miR-346 and FUS to elevate SP1 expression at the post-transcriptional level, thus strengthening the interaction between SP1 and β-catenin to activate the Wnt/β-catenin pathway. In turn, the downstream gene of Wnt/β-catenin signaling, SOX2 (SRY-box transcription factor 2), transcriptionally activated SP1 and therefore boosted circ_0026628 level. On the whole, SOX2-induced circ_0026628 sponged miR-346 and recruited FUS protein to augment SP1, triggering the downstream Wnt/β-catenin pathway to facilitate CRC progression.

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Hepatitis B virus X protein impedes the DNA repair via its association with transcription factor, TFIIH

BMC Microbiology ◽

10.1186/1471-2180-11-48 ◽

2011 ◽

Vol 11 (1) ◽

pp. 48 ◽

Cited By ~ 25

Author(s):

Ishtiaq Qadri ◽

Kaneez Fatima ◽

Hany AbdeL-Hafiz

Keyword(s):

Dna Repair ◽

Transcription Factor ◽

Hepatitis B Virus ◽

Hepatitis B ◽

X Protein ◽

B Virus

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POLYMORPHISMS OF BIOTRANSFORMATION AND DNA REPAIR GENES, DIETARY AND RISK OF COLORECTAL CANCER IN TAIWAN

Epidemiology ◽

10.1097/00001648-200407000-00393 ◽

2004 ◽

Vol 15 (4) ◽

pp. S150

Author(s):

Chih-Ching Yeh ◽

Fung-Chang Sung ◽

Reiping Tang ◽

Chung Rong Chang-Chieh ◽

Ling-Ling Hsieh

Keyword(s):

Colorectal Cancer ◽

Dna Repair ◽

Dna Repair Genes ◽

Repair Genes

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141 Mitochondrial transcription factor a mitochondrial DNA repair

Mitochondrion ◽

10.1016/j.mito.2009.12.132 ◽

2010 ◽

Vol 10 (2) ◽

pp. 240

Author(s):

Deborah L. Croteau ◽

Anne-Cécile V. Bayne ◽

Chandrika Canugovi ◽

Scott Maynard ◽

Nadja de Souza-Pinto ◽

...

Keyword(s):

Dna Repair ◽

Transcription Factor ◽

Mitochondrial Dna ◽

Mitochondrial Transcription ◽

Mitochondrial Transcription Factor ◽

Mitochondrial Dna Repair ◽

Mitochondrial Transcription Factor A

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Colorectal Cancer Metastasis: The DNA Repair Inhibitor Dbait Increases Sensitivity to Hyperthermia and Improves Efficacy of Radiofrequency Ablation

Radiology ◽

10.1148/radiol.13130805 ◽

2014 ◽

Vol 270 (3) ◽

pp. 736-746 ◽

Cited By ~ 16

Author(s):

Flavien Devun ◽

Julian Biau ◽

Michel Huerre ◽

Amélie Croset ◽

Jian-Sheng Sun ◽

...

Keyword(s):

Colorectal Cancer ◽

Dna Repair ◽

Radiofrequency Ablation ◽

Cancer Metastasis ◽

Colorectal Cancer Metastasis ◽

Dna Repair Inhibitor

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Structural basis of TFIIH activation for nucleotide excision repair

10.1101/628032 ◽

2019 ◽

Author(s):

Goran Kokic ◽

Aleksandar Chernev ◽

Dimitry Tegunov ◽

Christian Dienemann ◽

Henning Urlaub ◽

...

Keyword(s):

Dna Repair ◽

Transcription Factor ◽

Nucleotide Excision Repair ◽

Excision Repair ◽

Dna Lesions ◽

Structural Basis ◽

Disease Mutations ◽

Mechanistic Analysis ◽

Nucleotide Excision ◽

Dna Complex

AbstractGenomes are constantly threatened by DNA damage, but cells can remove a large variety of DNA lesions by nucleotide excision repair (NER)1. Mutations in NER factors compromise cellular fitness and cause human diseases such as Xeroderma pigmentosum (XP), Cockayne syndrome and trichothiodystrophy2,3. The NER machinery is built around the multisubunit transcription factor IIH (TFIIH), which opens the DNA repair bubble, scans for the lesion, and coordinates excision of the damaged DNA single strand fragment1,4. TFIIH consists of a kinase module and a core module that contains the ATPases XPB and XPD5. Here we prepare recombinant human TFIIH and show that XPB and XPD are stimulated by the additional NER factors XPA and XPG, respectively. We then determine the cryo-electron microscopy structure of the human core TFIIH-XPA-DNA complex at 3.6 Å resolution. The structure represents the lesion-scanning intermediate on the NER pathway and rationalizes the distinct phenotypes of disease mutations. It reveals that XPB and XPD bind double- and single-stranded DNA, respectively, consistent with their translocase and helicase activities. XPA forms a bridge between XPB and XPD, and retains the DNA at the 5’-edge of the repair bubble. Biochemical data and comparisons with prior structures6,7 explain how XPA and XPG can switch TFIIH from a transcription factor to a DNA repair factor. During transcription, the kinase module inhibits the repair helicase XPD8. For DNA repair, XPA dramatically rearranges the core TFIIH structure, which reorients the ATPases, releases the kinase module and displaces a ‘plug’ element from the DNA-binding pore in XPD. This enables XPD to move by ~80 Å, engage with DNA, and scan for the lesion in a XPG-stimulated manner. Our results provide the basis for a detailed mechanistic analysis of the NER mechanism.

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