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Science (New York, N.Y.) Dec 2022Neurons harbor high levels of single-strand DNA breaks (SSBs) that are targeted to neuronal enhancers, but the source of this endogenous damage remains unclear. Using...
Neurons harbor high levels of single-strand DNA breaks (SSBs) that are targeted to neuronal enhancers, but the source of this endogenous damage remains unclear. Using two systems of postmitotic lineage specification-induced pluripotent stem cell-derived neurons and transdifferentiated macrophages-we show that thymidine DNA glycosylase (TDG)-driven excision of methylcytosines oxidized with ten-eleven translocation enzymes (TET) is a source of SSBs. Although macrophage differentiation favors short-patch base excision repair to fill in single-nucleotide gaps, neurons also frequently use the long-patch subpathway. Disrupting this gap-filling process using anti-neoplastic cytosine analogs triggers a DNA damage response and neuronal cell death, which is dependent on TDG. Thus, TET-mediated active DNA demethylation promotes endogenous DNA damage, a process that normally safeguards cell identity but can also provoke neurotoxicity after anticancer treatments.
Topics: Cell Differentiation; DNA Demethylation; Induced Pluripotent Stem Cells; Neurons; DNA Breaks, Single-Stranded; Enhancer Elements, Genetic; Thymine DNA Glycosylase; DNA Repair; 5-Methylcytosine; Humans; Cell Transdifferentiation
PubMed: 36454826
DOI: 10.1126/science.add9838 -
Future Oncology (London, England) Jun 2021Trifluridine/tipiracil (FTD/TPI) is an orally active formulation of trifluridine, a thymidine-based nucleoside analog, and tipiracil hydrochloride, a thymidine...
Trifluridine/tipiracil (FTD/TPI) is an orally active formulation of trifluridine, a thymidine-based nucleoside analog, and tipiracil hydrochloride, a thymidine phosphorylase inhibitor that increases the bioavailability of trifluridine. Preliminary studies of FTD/TPI plus bevacizumab have produced encouraging results in the treatment of refractory metastatic colorectal cancer. Here, we describe the design of the multinational Phase III SUNLIGHT, an open-label study of FTD/TPI plus bevacizumab as third-line treatment for patients with unresectable metastatic colorectal cancer. A total of 490 patients will be randomized 1:1 to receive either FTD/TPI plus bevacizumab, or FTD/TPI monotherapy. The primary objective is to significantly improve overall survival with FTD/TPI plus bevacizumab compared with FTD/TPI monotherapy. The first patient was enrolled in November 2020.
Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Clinical Trials, Phase III as Topic; Colorectal Neoplasms; Drug Combinations; Female; Humans; Male; Middle Aged; Multicenter Studies as Topic; Neoplasm Metastasis; Pyrrolidines; Randomized Controlled Trials as Topic; Thymine; Trifluridine; Young Adult
PubMed: 33569986
DOI: 10.2217/fon-2020-1238 -
Future Oncology (London, England) Apr 2022Trifluridine/tipiracil is a compound drug, approved in 2015 by the US FDA, and in 2016 by the EMA, for the treatment of chemorefractory metastatic colorectal cancers,... (Review)
Review
Trifluridine/tipiracil is a compound drug, approved in 2015 by the US FDA, and in 2016 by the EMA, for the treatment of chemorefractory metastatic colorectal cancers, after the phase III RECOURSE trial demonstrated significant benefit. Another phase III trial (TAGS) showed significant improvement of overall survival and progression-free survival in refractory gastric cancer and gastroesophageal junction cancer, leading to further approval from the FDA on February 2019, followed by Japan in August 2019 and the EU in September 2019. As promising results have already been observed in the chemorefractory gastric and gastroesophageal-junction cancers, ongoing trials are assessing the use of trifluridine/tipiracil with other standard of care agents, aiming to further improve the survival rate of these patients.
Topics: Antineoplastic Combined Chemotherapy Protocols; Clinical Trials, Phase III as Topic; Drug Combinations; Humans; Pyrrolidines; Stomach Neoplasms; Thymine; Trifluridine
PubMed: 35081748
DOI: 10.2217/fon-2021-0754 -
Cancer Science Jul 2021Adjuvant chemotherapy has reduced the risk of tumor recurrence and improved survival in patients with resected colorectal cancer. Potential utility of circulating tumor... (Observational Study)
Observational Study Randomized Controlled Trial
Adjuvant chemotherapy has reduced the risk of tumor recurrence and improved survival in patients with resected colorectal cancer. Potential utility of circulating tumor DNA (ctDNA) prior to and post surgery has been reported across various solid tumors. We initiated a new type of adaptive platform trials to evaluate the clinical benefits of ctDNA analysis and refine precision adjuvant therapy for resectable colorectal cancer, named CIRCULATE-Japan including three clinical trials. The GALAXY study is a prospectively conducted large-scale registry designed to monitor ctDNA for patients with clinical stage II to IV or recurrent colorectal cancer who can undergo complete surgical resection. The VEGA trial is a randomized phase III study designed to test whether postoperative surgery alone is noninferior to the standard therapy with capecitabine plus oxaliplatin for 3 months in patients with high-risk stage II or low-risk stage III colon cancer if ctDNA status is negative at week 4 after curative surgery in the GALAXY study. The ALTAIR trial is a double-blind, phase III study designed to establish the superiority of trifluridine/tipiracil as compared with placebo in patients with resected colorectal cancer who show circulating tumor-positive status in the GALAXY study. Therefore, CIRCULATE-Japan encompasses both "de-escalation" and "escalation" trials for ctDNA-negative and -positive patients, respectively, and helps to answer whether measuring ctDNA postoperatively has prognostic and/or predictive value. Our ctDNA-guided adaptive platform trials will accelerate clinical development toward further precision oncology in the field of adjuvant therapy. Analysis of ctDNA status could be utilized as a predictor of risk stratification for recurrence and to monitor the effectiveness of adjuvant chemotherapy. ctDNA is a promising, noninvasive tumor biomarker that can aid in tumor monitoring throughout disease management.
Topics: Antineoplastic Combined Chemotherapy Protocols; Capecitabine; Chemotherapy, Adjuvant; Circulating Tumor DNA; Colonic Neoplasms; Colorectal Neoplasms; Double-Blind Method; Humans; Japan; Neoplasm Recurrence, Local; Oxaliplatin; Prospective Studies; Pyrrolidines; Thymine; Trifluridine
PubMed: 33931919
DOI: 10.1111/cas.14926 -
ChemistryOpen Apr 2020Dynamic and reversible non-covalent interactions endow synthetic systems and materials with smart adaptive functions that allow them to response to diverse stimuli,... (Review)
Review
Dynamic and reversible non-covalent interactions endow synthetic systems and materials with smart adaptive functions that allow them to response to diverse stimuli, interact with external agents, or repair structural defects. Inspired by the outstanding performance and selectivity of DNA in living systems, scientists are increasingly employing Watson-Crick nucleobase pairing to control the structure and properties of self-assembled materials. Two sets of complementary purine-pyrimidine pairs (guanine:cytosine and adenine:thymine(uracil)) are available that provide selective and directional H-bonding interactions, present multiple metal-coordination sites, and exhibit rich redox chemistry. In this review, we highlight several recent examples that profit from these features and employ nucleobase interactions in functional systems and materials, covering the fields of energy/electron transfer, charge transport, adaptive nanoparticles, porous materials, macromolecule self-assembly, or polymeric materials with adhesive or self-healing ability.
Topics: Adenine; Base Pairing; Coordination Complexes; Cytosine; DNA; Electron Transport; Energy Transfer; Guanine; Molecular Conformation; Oxidation-Reduction; Surface Properties; Thymine; Uracil
PubMed: 32257750
DOI: 10.1002/open.201900363