Postlabeling detection of DNA adducts of antitumor alkylating agents

Zhou, G.; Teicher, Beverly A.; Frei, Emil

doi:10.1007/s002800050450

Cited by 3 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The antineoplastic activity of alkylating agents has classically been linked to the direct induction of DNA adducts that result in single-and double-strand DNA breaks (57). However, from the first description of these compounds it has been clear that they can alkylate a variety of proteins, lipids, and other molecules (58).…”

Section: Discussionmentioning

confidence: 99%

Mechanisms of Lymphoma Clearance Induced by High-Dose Alkylating Agents

et al. 2019

View full text Add to dashboard Cite

The extraordinary activity of high-dose cyclophosphamide against some high-grade lymphomas was described nearly 60 years ago. Here we address mechanisms that mediate cyclophosphamide activity in bona fi de human double-hit lymphoma. We show that antibody resistance within the bone marrow (BM) is not present upon early engraftment but develops during lymphoma progression. This resistance required a high tumor:macrophage ratio, was recapitulated in spleen by partial macrophage depletion, and was overcome by multiple, high-dose alkylating agents. Cyclophosphamide induced endoplasmic reticulum (ER) stress in BM-resident lymphoma cells in vivo that resulted in ATF4-mediated paracrine secretion of VEGFA, massive macrophage infi ltration, and clearance of alemtuzumab-opsonized cells. BM macrophages isolated after cyclophosphamide treatment had increased phagocytic capacity that was reversed by VEGFA blockade or SYK inhibition. Single-cell RNA sequencing of these macrophages identifi ed a "super-phagocytic" subset that expressed CD36/FCGR4. Together, these fi ndings defi ne a novel mechanism through which high-dose alkylating agents promote macrophage-dependent lymphoma clearance. SIGNIFICANCE: mAbs are effective against only a small subset of cancers. Herein, we recapitulate compartment-specifi c antibody resistance and defi ne an ER stress-dependent mechanism induced by high-dose alkylating agents that promotes phagocytosis of opsonized tumor cells. This approach induces synergistic effects with mAbs and merits testing across additional tumor types.

show abstract

Section: Discussionmentioning

confidence: 99%

Mechanisms of Lymphoma Clearance Induced by High-Dose Alkylating Agents

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The chemistry and reactivity of nitrogen 8-10, 18, 20, 24, 47-56 and sulfur 44, 57-64 mustards with nucleosides and DNA in vitro is well studied. There are also numerous studies that examine the mustard derived DNA adducts from treated cell culture and animals, 46,48,50,54,56,59,64,65 including white blood cells of patients on chemotherapeutic regimens that include a nitrogen mustard.…”

Section: Discussionmentioning

confidence: 99%

“…There are also numerous studies that examine the mustard-derived DNA adducts from treated cells in culture and animals, 46,48,50,54,56,59,64,65 including white blood cells of patients on chemotherapeutic regimens that included a nitrogen mustard. 53,57 A variety of methods have been used to identify these adducts, including 32 P-postlabeling, 47,58 cochromatography by HPLC with authentic standards, 8,9,24,48,57 and mass spectrometry. 18,20,[49][50][51][52]56,59,64 Recently, tandem mass spectrometry with stable isotope dilution has been employed to identify and quantitate some of these DNA adducts.…”

Section: ■ Discussionmentioning

confidence: 99%

“…The labile N7-G and N3-A nitrogen and sulfur mustard adducts and their cross-links are often thermally hydrolyzed f r o m D N A u n d e r n e u t r a l 8 − 1 0 , 5 1 , 5 7 , 6 1 o r acidic 9,10,24,46,48,50,52,53,59 conditions. Alternatively, enzymatic digestion to the nucleosides has also been employed 18,20,47,49,54,58,65 and is necessary for DNA modifications that do not increase base lability (e.g., O 6 -dG adducts). Fapy nucleosides can exist as a number of slowly interconverting isomeric constituents such as αand β-anomers, furnanose and hexanose forms of the deoxyribose, geometric isomers of the formamide group, and possible atroisomers.…”

Section: ■ Discussionmentioning

confidence: 99%

“…The chemistry and reactivity of nitrogen − ,,,,− and sulfur ,− mustards with nucleosides and DNA in vitro are well-studied. There are also numerous studies that examine the mustard-derived DNA adducts from treated cells in culture and animals, ,,,,,,, including white blood cells of patients on chemotherapeutic regimens that included a nitrogen mustard. , A variety of methods have been used to identify these adducts, including 32 P-postlabeling, , co-chromatography by HPLC with authentic standards, ,,,, and mass spectrometry. ,,− ,,, Recently, tandem mass spectrometry with stable isotope dilution has been employed to identify and quantitate some of these DNA adducts. ,,− Collectively, the studies indicate that these electrophiles react predominantly at the N7 atom of dG, although N3-dA modification also can be significant . The toxicity of mustard agents has been attributed to interstrand DNA cross-links.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Characterization of Nitrogen Mustard Formamidopyrimidine Adduct Formation of Bis(2-chloroethyl)ethylamine with Calf Thymus DNA and a Human Mammary Cancer Cell Line

Gruppi

Hejazi

Christov

et al. 2015

Chem. Res. Toxicol.

View full text Add to dashboard Cite

A robust, quantitative ultraperformance liquid chromatography ion trap multistage scanning mass spectrometric (UPLC/MS3) method was established to characterize and measure five deoxyguanosine (dG) adducts formed by reaction of the chemotherapeutic nitrogen mustard (NM) bis-(2-chloroethyl)ethylamine with calf thymus (CT) DNA. In addition to the known N7-guanine (NM-G) adduct and its crosslink (G-NM-G), the ring-opened formamidopyrimidine (FapyG) mono-adduct (NM-FapyG) and cross-links in which one (FapyG-NM-G) or both (FapyG-NM-FapyG) guanines underwent ring-opening to FapyG units were identified. Authentic standards of all adducts were synthesized and characterized by NMR and mass spectrometry. These adducts were quantified in CT DNA treated with NM (1 μM) as their deglycosylated bases. A two-stage neutral thermal hydrolysis was developed to mitigate the artifactual formation of ring-opened FapyG adducts involving hydrolysis of the cationic adduct at 37 °C, followed by hydrolysis of the FapyG adducts at 95 °C. The limit of quantification values ranged between 0.3 and 1.6 adducts per 107 DNA bases, when the equivalent of 5 μg DNA hydrolysate was assayed on column. The principal adduct formed was the G-NM-G cross-link, followed by the NM-G mono-adduct; the FapyG-NM-FapyG adduct was at the limit of detection. The NM-FapyG adducts formed in CT DNA at a level of ~20% that of the NM-G adduct. NM-FapyG has not been previously quanitified and the FapyG-NM-G and FapyG-NM-FapyG adducts have not be previously characterized. Our validated analytical method was then applied to measure DNA adduct formation in the MDA-MB-231 mammary tumor cell line exposed to NM (100 μM) for 24 h. The major adduct formed was NM-G (970 adducts per 107 bases), followed by G-NM-G (240 adducts per 107 bases) and NM-FapyG (180 adducts per 107 bases), and lastly the FapyG-NM-G cross-link adduct (6.0 adducts per 107 bases). These lesions are expected to contribute to the NM-mediated toxicity and genotoxicity in vivo.

show abstract