scholarly journals Investigation of DNA Damage Induced by Alkylating Agents and Repair Pathways by Cooperating Mechanisms Driving the Formation of Colorectal Adenomas and Adenocarcinomas Using DNA Alkylation and DNA Methylation

2021 ◽  
pp. 353-394
Author(s):  
Elena Locci ◽  
Silvia Raymond
Keyword(s):  
Colorectal Cancer ◽  
Dna Damage ◽  
Alkylating Agents ◽  
Red Meat ◽  
Dna Alkylation ◽  
Colorectal Adenomas ◽  
The Other ◽  
Alkylation Damage ◽  
Keywords Cancer ◽  
Repair Pathways

In this recent study, DNA data from 900 patients with colorectal cancer were reviewed. Analysis of the data showed a distinct mutation signature, a pattern that had never been identified before but indicated a type of DNA damage called "alkylation." Red meat contains chemicals that can cause alkylation. High levels of tumor alkylation damage are seen only in patients who consume an average of more than 150 grams of meat per day, roughly equivalent to two or more meals. On the other hand, a group of researchers in 2019 in a controversial conclusion stated that they do not have much confidence in reducing deaths from colon cancer by avoiding red meat. Keywords: Cancer; Cells; Tissues, Tumors; Prevention, Prognosis; Diagnosis; Imaging; Screening; Treatment; Management

scholarly journals Indication of a Type of DNA Damage Called "Alkylation" as High Levels of Tumor Alkylation Damage

2021 ◽  
pp. 342-380
Author(s):  
Ricardo Gobato ◽  
Abhijit Mitra
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
Dna Damage ◽  
Cancer Cells ◽  
Red Meat ◽  
The Other ◽  
Alkylation Damage ◽  
Treatment Management ◽  
Other Hand ◽  
Keywords Cancer

In this recent study, DNA data from 900 patients with colorectal cancer were reviewed. Analysis of the data showed a distinct mutation signature, a pattern that had never been identified before but indicated a type of DNA damage called "alkylation." Red meat contains chemicals that can cause alkylation. High levels of tumor alkylation damage are seen only in patients who consume an average of more than 150 grams of meat per day, roughly equivalent to two or more meals. On the other hand, a group of researchers in 2019 in a controversial conclusion stated that they do not have much confidence in reducing deaths from colon cancer by avoiding red meat. Keywords: Cancer; Cells; Tissues; Tumors; Prevention; Prognosis; Diagnosis; Imaging; Screening, Treatment; Management

scholarly journals A ”Clickable” Probe for Active MGMT in Glioblastoma Demonstrates Two Discrete Populations of MGMT

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 453 ◽  
Author(s):  
Sudhir Raghavan ◽  
David S. Baskin ◽  
Martyn A. Sharpe
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Cancer Cells ◽  
Dna Adducts ◽  
Alkylating Agents ◽  
Chemotherapeutic Agents ◽  
Dna Alkylation ◽  
Methylated Dna ◽  
Methylguanine Methyltransferase ◽  
Discrete Populations

Various pathways can repair DNA alkylation by chemotherapeutic agents such as temozolomide (TMZ). The enzyme O6-methylguanine methyltransferase (MGMT) removes O6-methylated DNA adducts, leading to the failure of chemotherapy in resistant glioblastomas. Because of the anti-chemotherapeutic activities of MGMT previously described, estimating the levels of active MGMT in cancer cells can be a significant predictor of response to alkylating agents. Current methods to detect MGMT in cells are indirect, complicated, time-intensive, or utilize molecules that require complex and multistep chemistry synthesis. Our design simulates DNA repair by the transfer of a clickable propargyl group from O6-propargyl guanine to active MGMT and subsequent attachment of fluorescein-linked PEG linker via ”click chemistry.” Visualization of active MGMT levels reveals discrete active and inactive MGMT populations with biphasic kinetics for MGMT inactivation in response to TMZ-induced DNA damage.

scholarly journals Glutamine deficiency induces DNA alkylation damage and sensitizes cancer cells to alkylating agents through inhibition of ALKBH enzymes

PLoS Biology ◽  
2017 ◽  
Vol 15 (11) ◽  
pp. e2002810 ◽  
Author(s):  
Thai Q. Tran ◽  
Mari B. Ishak Gabra ◽  
Xazmin H. Lowman ◽  
Ying Yang ◽  
Michael A. Reid ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Alkylating Agents ◽  
Dna Alkylation ◽  
Alkylation Damage

scholarly journals DNA Alkylation Damage as a Sensor of Nitrosative Stress in Mycobacterium tuberculosis

2003 ◽  
Vol 71 (2) ◽  
pp. 997-1000 ◽  
Author(s):  
Steven I. Durbach ◽  
Burkhard Springer ◽  
Edith E. Machowski ◽  
Robert J. North ◽  
K. G. Papavinasasundaram ◽  
...  
Keyword(s):  
Dna Damage ◽  
Mycobacterium Tuberculosis ◽  
Nitrosative Stress ◽  
Dna Alkylation ◽  
Genotoxic Effects ◽  
Alkylation Damage ◽  
Damage Repair

ABSTRACT One of the cellular consequences of nitrosative stress is alkylation damage to DNA. To assess whether nitrosative stress is registered on the genome of Mycobacterium tuberculosis, mutants lacking an alkylation damage repair and reversal operon were constructed. Although hypersensitive to the genotoxic effects of N-methyl-N′-nitro-N-nitrosoguanidine in vitro, the mutants displayed no phenotype in vivo, suggesting that permeation of nitrosative stress to the level of cytotoxic DNA damage is restricted.

scholarly journals Versatile Cell-Based Assay for Measuring Base Excision Repair of DNA Alkylation Damage

2021 ◽  
Author(s):  
Yong Li ◽  
Peng Mao ◽  
Evelina Y. Basenko ◽  
Zachary Lewis ◽  
Michael Smerdon ◽  
...  
Keyword(s):  
Dna Damage ◽  
Base Excision Repair ◽  
Cultured Cells ◽  
Excision Repair ◽  
Dna Alkylation ◽  
Model Systems ◽  
Environmental Carcinogens ◽  
Alkylation Damage ◽  
Chemotherapy Drugs ◽  
Base Excision

AbstractDNA alkylation damage induced by environmental carcinogens, chemotherapy drugs, or endogenous metabolites plays a central role in mutagenesis, carcinogenesis, and cancer therapy. Base excision repair (BER) is a conserved, front line DNA repair pathway that removes alkylation damage from DNA. The capacity of BER to repair DNA alkylation varies markedly between different cell types and tissues, which correlates with cancer risk and cellular responses to alkylation chemotherapy. The ability to measure cellular rates of alkylation damage repair by the BER pathway is critically important for better understanding of the fundamental processes involved in carcinogenesis, and also to advance development of new therapeutic strategies. Methods for assessing the rates of alkylation damage and repair, especially in human cells, are limited, prone to significant variability due to the unstable nature of some of the alkyl adducts, and often rely on indirect measurements of BER activity. Here, we report a highly reproducible and quantitative, cell-based assay, named alk-BER (alkylation Base Excision Repair) for measuring rates of BER following alkylation DNA damage. The alk-BER assay involves specific detection of methyl DNA adducts (7-methyl guanine and 3-methyl adenine) directly in genomic DNA. The assay has been developed and adapted to measure the activity of BER in fungal model systems and human cell lines. Considering the specificity and conserved nature of BER enzymes, the assay can be adapted to virtually any type of cultured cells. Alk-BER offers a cost efficient and reliable method that can effectively complement existing approaches to advance integrative research on mechanisms of alkylation DNA damage and repair.

scholarly journals Repair of DNA alkylation damage.

1998 ◽  
Vol 45 (1) ◽  
pp. 191-202 ◽  
Author(s):  
M Bouziane ◽  
F Miao ◽  
N Ye ◽  
G Holmquist ◽  
G Chyzak ◽  
...  
Keyword(s):  
Dna Damage ◽  
Mammalian Cells ◽  
Excision Repair ◽  
Alkylating Agents ◽  
Phosphoglycerate Kinase ◽  
Amino Acid Sequences ◽  
Dna Glycosylases ◽  
Alkylation Damage ◽  
Base Excision ◽  
Methylating Agents

Alkylation damage of DNA is one of the major types of insults which cells must repair to remain viable. One way alkylation damaged ring nitrogens are repaired is via the Base Excision Repair (BER) pathway. Examination of mutants in both BER and Nucleotide Excision Repair show that there is actually an overlap of repair by these two pathways for the removal of cytotoxic lesions in Escherichia coli. The enzymes removing damaged bases in the first step in the BER pathway are DNA glycosylases. The coding sequences for a number of methylpurine-DNA glycosylases (MPG proteins) were cloned, and a comparison of the amino-acid sequences shows that there are some similarities between these proteins, but nonetheless, compared to other DNA glycosylases, MPG proteins are more divergent. MPG proteins have been purified to homogeneity and used to identify their substrates ranging from methylating agents to deamination products to oxidatively damaged bases. The ligation-mediated polymerase chain reaction has been used to study the formation of alkylation damage, and its repair in mammalian cells. We have studied DNA damage in the PGK1 gene for a series of DNA alkylating agents including N-methyl-N'-nitro-N-nitrosoguanidine, Mechlorethamine, and Chlorambucil and shown that the damage observed in the PGK1 (phosphoglycerate kinase 1) gene depends on the alkylating agent used. This report reviews the literature on the MPG proteins, DNA glycosylases removing 3-methyladenine, and the use of these enzymes to detect DNA damage at the nucleotide level.

scholarly journals Understanding of the activity of a protein involved in DNA repair by biochemical, structural and in silico approaches

2017 ◽  
Author(s):  
Castrese Morrone ◽  
Riccardo Miggiano ◽  
Mario Serpe ◽  
Alberto Massarotti ◽  
Anna Valenti ◽  
...  
Keyword(s):  
Conformational Changes ◽  
In Silico ◽  
Intramolecular Interaction ◽  
Alkylating Agents ◽  
Dna Alkylation ◽  
Structural Rearrangements ◽  
Reaction Cycle ◽  
Alkylation Damage ◽  
Starting Point ◽  
Dna Alkyltransferase

The repair of DNA from alkylation damage is generally performed by evolutionary conserved protein complexes. However, specific repair of O6-alkylated-guanines is a task of a small class of proteins called AGTs (alkylated DNA-protein alkyl-transferases): by using a single-step reaction mechanism, the alkylic group is irreversibly transferred to a catalytic cysteine in the active site, inducing the in vitro and in vivo inactivation and destabilization of the protein. Although some conformational changes after the alkylation are supposed, a complete picture of structural rearrangements occurring during the reaction cycle is missing. The complete knowledge of these structural movements is a great challenge and a fundamental task for the development of new inhibitors of the human AGT, whose overexpression leads to a resistance in several types of tumor cells to the chemoterapic alkylating agents-based treatment. We used the Sulfolobus solfataricus thermostable ortholog (SsOGT) as a model for AGTs [1], by performing biochemical, structural, molecular dynamics and in silico analysis of ligand-free, DNA-bound and alkylated version of the protein. With this protein, we were able to highlight conformational changes and perturbations of intramolecular interaction occurring during lesion recognition and catalysis, confirming our previous hypothesis that coordination between the N- and C-terminal domains of SsOGT is important for protein activity and stability [2]. All the data allowed us to propose a general model of structural rearrangements occurring during the reaction cycle of AGTs [3], and proposing it as a starting point to design strategies to modulate AGT activity in therapeutic settings. [1] G. Perugino, A. Vettone, G. Illiano, A. Valenti, M.C. Ferrara, M. Rossi, M. Ciaramella (2012) Activity and regulation of archaeal DNA alkyltransferase: conserved protein involved in repair of DNA alkylation damage. J. Biol. Chem., 287, 4222-4231. [2] G.Perugino, R.Miggiano, M.Serpe, A.Vettone, A.Valenti, S.Lahiri, F.Rossi, M.Rossi, M. Rizzi, M. Ciaramella (2015) Structure-function relationships governing activity and stability of a DNA alkylation damage repair thermostable protein. Nucleic Acids Res., 43, 8801-8816. [3] C. Morrone, R. Miggiano, M. Serpe, A. Massarotti, A. Valenti, G. del Monaco, M. Rossi, F. Rossi, M. Rizzi, G. Perugino, M. Ciaramella (2017) Interdomain interactions rearrangements control the reaction steps of a thermostable DNA alkyltransferase. BBA-Gen. Sub., 1861, 2, 86-96.

ACNU-resistant mutants of 9L rat glioma cell line

1985 ◽  
Vol 63 (4) ◽  
pp. 583-588 ◽  
Author(s):  
Takashi Kokunai ◽  
Norihiko Tamaki ◽  
Satoshi Matsumoto
Keyword(s):  
Cell Line ◽  
Glioma Cell ◽  
Early Stage ◽  
Alkylating Agents ◽  
Glioma Cell Line ◽  
Dna Alkylation ◽  
Cross Resistance ◽  
Alkylation Damage ◽  
Content Type ◽  
Rat Glioma

✓ Three ACNU-resistant subclones were isolated and characterized from a wild-typed 9L rat glioma cell line in culture. At an early stage after cloning, these ACNU-resistant subclones showed a high frequency of chromosomal aberrations compared with nonresistant 9L cells. These ACNU-resistant subclones revealed a cross resistance to BCNU, CCNU, methyl CCNU, nitrogen mustard, cyclophosphamide, and cis-platinum, which are alkylating agents. Further studies are necessary to clarify the mechanisms of ACNU-resistance from the aspect of repair of DNA alkylation damage.

scholarly journals Versatile cell-based assay for measuring DNA alkylation damage and its repair

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yong Li ◽  
Peng Mao ◽  
Evelina Y. Basenko ◽  
Zachary Lewis ◽  
Michael J. Smerdon ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cultured Cells ◽  
Excision Repair ◽  
Cell Types ◽  
Dna Alkylation ◽  
Model Systems ◽  
Environmental Carcinogens ◽  
Alkylation Damage ◽  
Chemotherapy Drugs ◽  
Integrative Research

AbstractDNA alkylation damage induced by environmental carcinogens, chemotherapy drugs, or endogenous metabolites plays a central role in mutagenesis, carcinogenesis, and cancer therapy. Base excision repair (BER) is a conserved, front line DNA repair pathway that removes alkylation damage from DNA. The capacity of BER to repair DNA alkylation varies markedly between different cell types and tissues, which correlates with cancer risk and cellular responses to alkylation chemotherapy. The ability to measure cellular rates of alkylation damage repair by the BER pathway is critically important for better understanding of the fundamental processes involved in carcinogenesis, and also to advance development of new therapeutic strategies. Methods for assessing the rates of alkylation damage and repair, especially in human cells, are limited, prone to significant variability due to the unstable nature of some of the alkyl adducts, and often rely on indirect measurements of BER activity. Here, we report a highly reproducible and quantitative, cell-based assay, named alk-BER (alkylation Base Excision Repair) for measuring rates of BER following alkylation DNA damage. The alk-BER assay involves specific detection of methyl DNA adducts (7-methyl guanine and 3-methyl adenine) directly in genomic DNA. The assay has been developed and adapted to measure the activity of BER in fungal model systems and human cell lines. Considering the specificity and conserved nature of BER enzymes, the assay can be adapted to virtually any type of cultured cells. Alk-BER offers a cost efficient and reliable method that can effectively complement existing approaches to advance integrative research on mechanisms of alkylation DNA damage and repair.

Sign in / Sign up

Export Citation Format

Share Document