A DFTB study on the electronic response of encapsulated DNA nucleobases onto chiral CNTs as a sequencer.

Sequencing the DNA nucleobases is essential in the diagnosis and treatment of many diseases related to human genes. In this article, the encapsulation of DNA nucleobases with some of the important synthesized chiral (7, 6), (8, 6), and (10, 8) carbon nanotubes were investigated. The structures were modeled by applying density functional theory based on tight binding method (DFTB) by considering semi-empirical basis sets. Encapsulating DNA nucleobases on the inside of CNTs caused changes in the electronic properties of the selected chiral CNTs. The results confirmed that van der Waals (vdW) interactions, π-orbitals interactions, non-bonded electron pairs, and the presence of high electronegative atoms are the key factors for these changes. The result of electronic parameters showed that among the CNTs, CNT (8, 6) is a suitable choice in sequencing guanine (G) and cytosine (C) DNA nucleobases. However, they are not able to sequence adenine (A) and thymine (T). According to the band gap energy engineering approach and absorption energy, the presence of G and C DNA nucleobases decreased the band gap energy of CNTs. Hence selected CNTs suggested as biosensor substrates for sequencing G and C DNA nucleobases.

Sequencing considerations in the third-line treatment of metastatic colorectal cancer.

Numerous advances in the standard of care for metastatic colorectal cancer (mCRC), including the approval of several new treatments indicated for treatment in the third line or later (3L+), have been made, yet data and appropriate guidance on the optimal sequencing and treatment strategies for these lines of therapy are lacking. Four treatments-regorafenib, trifluridine/tipiracil alone or with bevacizumab, and fruquintinib-are FDA-approved and recommended by the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for the treatment of mCRC in the 3L+. When considering sequencing of treatment options for patients in the 3L+, the goal of treatment is to improve survival, but also maintain quality of life, a goal that requires consideration of relative efficacy and cumulative toxicity such as persistent myelosuppression.

A folate inhibitor exploits metabolic differences in Pseudomonas aeruginosa for narrow-spectrum targeting.

Pseudomonas aeruginosa is a leading cause of hospital-acquired infections for which the development of antibiotics is urgently needed. Unlike most enteric bacteria, P. aeruginosa lacks enzymes required to scavenge exogenous thymine. An appealing strategy to selectively target P. aeruginosa is to disrupt thymidine synthesis while providing exogenous thymine. However, known antibiotics that perturb thymidine synthesis are largely inactive against P. aeruginosa.Here we characterize fluorofolin, a dihydrofolate reductase (DHFR) inhibitor derived from Irresistin-16, that exhibits significant activity against P. aeruginosa in culture and in a mouse thigh infection model. Fluorofolin is active against a wide range of clinical P. aeruginosa isolates resistant to known antibiotics. Metabolomics and in vitro assays using purified folA confirm that fluorofolin inhibits P. aeruginosa DHFR. Importantly, in the presence of thymine supplementation, fluorofolin activity is selective for P. aeruginosa. Resistance to fluorofolin can emerge through overexpression of the efflux pumps MexCD-OprJ and MexEF-OprN, but these mutants also decrease pathogenesis. Our findings demonstrate how understanding species-specific genetic differences can enable selective targeting of important pathogens while revealing trade-offs between resistance and pathogenesis.

The emerging emetogenicity of trifluridine/tipiracil (TAS­102) from patient self-reporting: a multicenter, prospective, observational study.

BACKGROUND: Trifluridine/tipiracil (TAS-102) is an oral anticancer drug with adequate efficacy in unresectable colorectal cancer, but frequently also induces chemotherapy-induced nausea and vomiting (CINV). To investigate the occurrence of CINV and antiemetic therapy in patients with colorectal cancer treated with TAS-102 (JASCC-CINV 2001). METHODS: We conducted a multicenter, prospective, observational study in patients with colorectal cancer who received TAS-102 without dose reduction for the first time. Primary endpoint was the incidence of vomiting during the overall period. Secondary endpoints were the incidence of nausea, significant nausea, anorexia, other adverse events (constipation, diarrhea, insomnia, fatigue, dysgeusia) and patient satisfaction. Patient diaries were used for primary and secondary endpoints. All adverse events were subjectively assessed using PRO-CTCAE ver 1.0. and CTCAE ver 5.0. RESULTS: Data from 100 of the 119 enrolled patients were analyzed. The incidence of vomiting, nausea, and significant nausea was 13%, 67%, and 36%, respectively. The incidence of vomiting in patients with and without prophylactic antiemetic therapy were 20.8% and 10.5%, respectively. Prophylactic antiemetics were given to 24% of patients, of whom 70% received D2 antagonists. Multivariate Cox proportional hazards analysis showed that experience of CINV in previous treatment tended to be associated with vomiting (hazard ratio [HR]: 7.13, 95% confidence interval [CI]: 0.87-58.5, P = 0.07), whereas prophylactic antiemetic administration was not (HR: 1.61, 95 CI: 0.50-5.21, P = 0.43). With regard to patient satisfaction, the proportion of patients who were "very satisfied," "satisfied," "slightly satisfied" or "somewhat satisfied" was 81.8%. CONCLUSIONS: The low incidence of vomiting and high patient satisfaction suggest that TAS-102 does not require the use of uniform prophylactic antiemetic treatments. However, patients with the experience of CINV in previous treatment might require prophylactic antiemetic treatment.

Efficacy of Regorafenib and Trifluridine/Tipiracil According to Extended RAS Evaluation in Advanced Metastatic Colorectal Cancer Patients: A Multicenter Retrospective Analysis.

BACKGROUND: There are few molecular markers driving treatment selection in later lines of treatment for advanced colorectal cancer patients. The vast majority of patients who progress after first- and second-line therapy undergo chemotherapy regardless of molecular data. OBJECTIVE: We aimed to assess the prognostic and predictive effects of specific RAS mutations on overall survival of patients receiving regorafenib (rego), trifluridine/tipiracil (TFD/TPI), or both. PATIENTS AND METHODS: This was a retrospective observational study based on data from a previous study of our research network, involving nine Italian institutions over a 10-year timeframe (2012-2022). Extended RAS analysis, involving KRAS exon 2-4 and NRAS exon 2-4, and BRAF were the main criteria for inclusion in this retrospective evaluation. Patients with BRAF mutation were excluded. Patients were classified according to treatment (rego- or TFD/TPI-treated) and RAS mutational status (wild-type [WT], KRAS codon 12 mutations, KRAS codon 13 mutations, KRAS rare mutations and NRAS mutations, KRAS G12C mutation and KRAS G12D mutation). RESULTS: Overall, 582 patients were included in the present analysis. Overall survival did not significantly differ in rego-treated patients according to RAS extended analysis, although a trend toward a better median survival in patients carrying G12D mutation (12.0 months), Codon 13 mutation (8.0 months), and Codon 12 mutation (7.0 months) has been observed, when compared with WT patients (6.0 months). Overall survival did not significantly differ in TFD/TPI-treated patients according to RAS extended analysis, although a trend toward a better median survival in WT patients had been observed (9.0 months) in comparison with the entire population (7.0 months). Patients receiving both drugs displayed a longer survival when compared with the population of patients receiving rego alone (p = 0.005) as well as the population receiving TFD/TPI alone (p < 0.001), suggesting a group enriched for favorable prognostic factors. However, when each group was analyzed separately, the addition of TFD/TPI therapy to the rego-treated group improved survival only in all-RAS WT patients (p = 0.003). Differently, the addition of rego therapy to TFD/TPI-treated patients significantly improved OS in the Codon 12 group (p = 0.0004), G12D group (p = 0.003), and the rare mutations group (p = 0.02), in addition to all-RAS WT patients (p = 0.002). The rego-TFD/TPI sequence, compared with the reverse sequence, significantly improved OS only in the KRAS codon 12 group (p = 0.003). CONCLUSIONS: Our data demonstrate that RAS mutations do not affect outcome in rego-treated patients as well as TFD/TPI-treated patients. Nevertheless, a trend toward a higher efficacy of rego in RAS-mutated (in particular codon 12, rare RAS mutations, and G12D) patients has been recorded. The rego-TFD/TPI sequence seems to be superior to the reverse sequence in patients carrying an RAS codon 12 mutation, although the impact of other factors as disease burden or performance status cannot be excluded.

Morphological Transformation and Surface Engineering of Glycovesicles Driven by Bioinspired Hydrogen Bonds of Nucleobases.

Glycopolymer-based supramolecular glycoassemblies with signal-driven cascade morphological deformation and accessible surface engineering toward bioinspired functional glycomaterials have attracted much attention due to their diverse applications in fundamental and practical scenarios. Herein, we achieved the cascade morphological transformation and surface engineering of a nucleobase-containing polymeric glycovesicle through exploiting the bioinspired complementary multiple hydrogen bonds of complementary nucleobases. First, the synthesized thymine-containing glycopolymers (PGal30-b-PTAm249) are capable of self-assembling into well-defined glycovesicles. Several kinds of amphiphilic adenine-containing block copolymers with neutral, positive, and negative charges were synthesized to engineer the glycovesicles through the multiple hydrogen bonds between adenine and thymine. A cascade of morphological transformations from vesicles to ruptured vesicles with tails, to worm-like micelles, and finally to spherical micelles were observed via continuously adding the adenine-containing polymer into the thymine-containing glycovesicles. Furthermore, the surface charge properties of these glyconano-objects can be facilely regulated through incorporating various adenine-containing polymers. This work demonstrates the potential application of a unique bioinspired approach to precisely engineer the morphology and surface properties of glycovesicles for boosting their biological applications.

Predictive significance of FGFR4 p.G388R polymorphism in metastatic colorectal cancer patients receiving trifluridine/tipiracil (TAS-102) treatment.

BACKGROUND: TAS-102 (Lonsurf®) is an oral fluoropyrimidine consisting of a combination of trifluridine (a thymidine analog) and tipiracil (a thymidine phosphorylation inhibitor). The drug is effective in metastatic colorectal cancer (mCRC) patients refractory to fluorouracil, irinotecan and oxaliplatin. This study is a real-world analysis, investigating the interplay of genotype/phenotype in relation to TAS-102 sensitivity. METHODS: Forty-seven consecutive mCRC patients were treated with TAS-102 at the National Cancer Institute of Naples from March 2019 to March 2021, at a dosage of 35 mg/m2, twice a day, in cycles of 28 days (from day 1 to 5 and from day 8 to 12). Clinical-pathological parameters were described. Activity was evaluated with RECIST criteria (v1.1) and toxicity with NCI-CTC (v5.0). Survival was depicted through the Kaplan-Meyer curves. Genetic features of patients were evaluated with Next Generation Sequencing (NGS) through the Illumina NovaSeq 6000 platform and TruSigt™Oncology 500 kit. RESULTS: Median age of patients was 65 years (range: 46-77). Forty-one patients had 2 or more metastatic sites and 38 patients underwent to more than 2 previous lines of therapies. ECOG (Eastern Cooperative Oncology Group) Performance Status (PS) was 2 in 19 patients. The median number of TAS-102 cycles was 4 (range: 2-12). The most frequent toxic event was neutropenia (G3/G4 in 16 patients). There were no severe (> 3) non-haematological toxicities or treatment-related deaths. Twenty-six patients experienced progressive disease (PD), 21 stable disease (SD). Three patients with long-lasting disease control (DC: complete, partial responses or stable disease) shared an FGFR4 (p.Gly388Arg) mutation. Patients experiencing DC had more frequently a low tumour growth rate (P = 0.0306) and an FGFR4 p.G388R variant (P < 0.0001). The FGFR4 Arg388 genotype was associated with better survival (median: 6.4 months) compared to the Gly388 genotype (median: 4 months); the HR was 0.25 (95% CI 0.12- 0.51; P = 0.0001 at Log-Rank test). CONCLUSIONS: This phenotype/genotype investigation suggests that the FGFR4 p.G388R variant may serve as a new marker for identifying patients who are responsive to TAS-102. A mechanistic hypothesis is proposed to interpret these findings.

The Importance of Anharmonicity and Solvent Effects on the OH Radical Attack on Nucleobases.

Previous theoretical investigations of the reactions between an OH radical and a nucleobase have stated the most important pathways to be the C5-C6 addition for pyrimidines and the C8 addition for purines. Furthermore, the abstraction of a methyl hydrogen from thymine has also been proven an important pathway. The conclusions were based solely on gas-phase calculations and harmonic vibrational frequencies. In this paper, we supplement the calculations by applying solvent corrections through the polarizable continuum model (PCM) solvent model and applying anharmonicity in order to determine the importance of anharmonicity and solvent effects. Density functional theory (DFT) at the ωB97-D/6-311++G(2df,2pd) level with the Eckart tunneling correction is used. The total reaction rate constants are found to be 1.48 ×10-13 cm3 molecules-1s-1 for adenine, 1.02 ×10-11 cm3 molecules-1s-1 for guanine, 5.52 ×10-13 cm3 molecules-1s-1 for thymine, 1.47 ×10-13 cm3 molecules-1s-1 for cytosine and 7.59 ×10-14 cm3 molecules-1s-1 for uracil. These rates are found to be approximately two orders of magnitude larger than experimental values. We find that the tendencies observed for preferred pathways for reactions calculated in a solvent are comparable to the preferred pathways for reactions calculated in gas phase. We conclude that applying a solvent has a larger impact on more parameters compared to the inclusion of anharmonicity. For some reactions the inclusion of anharmonicity has no effect, whereas for others it does impact the energetics.

Gene identification and enzymatic characterization of the initial enzyme in pyrimidine oxidative metabolism, uracil-thymine dehydrogenase.

Uracil-thymine dehydrogenase (UTDH), which catalyzes the irreversible oxidation of uracil to barbituric acid in oxidative pyrimidine metabolism, was purified from Rhodococcus erythropolis JCM 3132. The finding of unusual stabilizing conditions (pH 11, in the presence of NADP+ or NADPH) enabled the enzyme purification. The purified enzyme was a heteromer consisting of three different subunits. The enzyme catalyzed oxidation of uracil to barbituric acid with artificial electron acceptors such as methylene blue, phenazine methosulfate, benzoquinone, and α-naphthoquinone; however, NAD+, NADP+, flavin adenine dinucleotide, and flavin mononucleotide did not serve as electron acceptors. The enzyme acted not only on uracil and thymine but also on 5-halogen-substituted uracil and hydroxypyrimidine (pyrimidone), while dihydropyrimidine, which is an intermediate in reductive pyrimidine metabolism, and purine did not serve as substrates. The activity of UTDH was enhanced by cerium ions, and this activation was observed with all combinations of substrates and electron acceptors.

Protocol of a phase II study investigating the efficacy and safety of trifluridine/tipiracil plus ramucirumab as a third-line or later treatment for advanced gastric cancer.

In Japan, systemic chemotherapy is the standard treatment for unresectable, advanced, or recurrent gastric cancer. However, numerous patients with gastric cancer do not receive late-line treatment because of the rapid progression of gastric cancer. Additionally, late-line treatments, such as nivolumab, trifluridine tipiracil (FTD/TPI), or irinotecan, have limited effects on improving clinical symptoms and delaying the onset of symptoms associated with cancer progression. Recently, a combination of FTD/TPI and ramucirumab was reported to have a high response rate in late-line treatment; however, owing to patient selection bias and a high rate of hematologic toxicity in that previous study, this regimen may not be feasible in real-world clinical applications. Our objective is to conduct a single-arm phase II study to assess the safety and efficacy of FTD/TPI plus ramucirumab combination therapy for gastric cancer after third-line treatment under real-world clinical conditions. This study will recruit 32 patients according to eligibility criteria and administer FTD/TPI (35 mg/m2) and intravenous ramucirumab (8 mg/kg). The primary endpoint will be the time to treatment failure. The secondary endpoints will include the overall survival time, progression-free survival time, overall response rate, disease control rate, relative dose intensity, and incidence of adverse events. The results will add new insights for improving the late-line treatment of advanced gastric cancer.

Ultrafast and Multichannel Generation of the Triplet State in DNA-Intercalated Gilvocarcin V for an Enhanced Photoaddition Reaction.

Gilvocarcin V (GV) is a natural antibiotic exhibiting excellent antitumor activities and remarkably low toxicity in near-ultraviolet or visible light-dependent treatment. Notwithstanding, the [2 + 2] cycloaddition reaction between GV and thymine has been proven to be the key for its function in photodynamic therapy, and crucial mechanistic details about such a reaction are poorly understood. In this study, the electronic relaxation pathways and photoaddition reaction are characterized by femto- to nanosecond time-resolved spectroscopy combined with quantum chemical calculation. Our results reveal that ultrafast intersystem crossing (<3 ps) leads to the population of a local triplet excited state in DNA-intercalated GV. Such a state can further induce the formation of a biradical state, which is identified as the important reactive precursor for photoaddition between GV and thymine. The overall photoaddition quantum efficiency is determined to be 11.57 ± 1.0%. These results are essential to the elucidation of the DNA photoaddition mechanism of C-aryl glycoside-based artificial photocytotoxic agents and could help further development of those medicines.

Genomic and Epigenomic Changes in the Progeny of Cold-Stressed Arabidopsis thaliana Plants.

Plants are continuously exposed to various environmental stresses. Because they can not escape stress, they have to develop mechanisms of remembering stress exposures somatically and passing it to the progeny. We studied the Arabidopsis thaliana ecotype Columbia plants exposed to cold stress for 25 continuous generations. Our study revealed that multigenerational exposure to cold stress resulted in the changes in the genome and epigenome (DNA methylation) across generations. Main changes in the progeny were due to the high frequency of genetic mutations rather than epigenetic changes; the difference was primarily in single nucleotide substitutions and deletions. The progeny of cold-stressed plants exhibited the higher rate of missense non-synonymous mutations as compared to the progeny of control plants. At the same time, epigenetic changes were more common in the CHG (C = cytosine, H = cytosine, adenine or thymine, G = guanine) and CHH contexts and favored hypomethylation. There was an increase in the frequency of C to T (thymine) transitions at the CHH positions in the progeny of cold stressed plants; because this type of mutations is often due to the deamination of the methylated cytosines, it can be hypothesized that environment-induced changes in methylation contribute to mutagenesis and may be to microevolution processes and that RNA-dependent DNA methylation plays a crucial role. Our work supports the existence of heritable stress response in plants and demonstrates that genetic changes prevail.

Impact of KRASG12 mutations on survival with trifluridine/tipiracil plus bevacizumab in patients with refractory metastatic colorectal cancer: post hoc analysis of the phase III SUNLIGHT trial.

BACKGROUND: In metastatic colorectal cancer (mCRC), KRAS mutations are often associated with poorer survival; however, the prognostic impact of specific point mutations is unclear. In the phase III SUNLIGHT trial, trifluridine/tipiracil (FTD/TPI) plus bevacizumab significantly improved overall survival (OS) versus FTD/TPI alone. We assessed the impact of KRASG12 mutational status on OS in SUNLIGHT. PATIENTS AND METHODS: In the global, open-label, randomized, phase III SUNLIGHT trial, adults with mCRC who had received no more than two prior chemotherapy regimens were randomized 1 : 1 to receive FTD/TPI alone or FTD/TPI plus bevacizumab. In this post hoc analysis, OS was assessed according to the presence or absence of a KRASG12 mutation in the overall population and in patients with RAS-mutated tumors. RESULTS: Overall, 450 patients were analyzed, including 302 patients in the RAS mutation subgroup (214 with a KRASG12 mutation and 88 with a non-KRASG12RAS mutation). In the overall population, similar OS outcomes were observed in patients with and without a KRASG12 mutation [median 8.3 and 9.2 months, respectively; hazard ratio (HR) 1.09, 95% confidence interval (CI) 0.87-1.4]. Similar OS outcomes were also observed in the subgroup analysis of patients with a KRASG12 mutation versus those with a non-KRASG12RAS mutation (HR 1.03, 95% CI 0.76-1.4). FTD/TPI plus bevacizumab improved OS compared with FTD/TPI alone irrespective of KRASG12 mutational status. Among patients with a KRASG12 mutation, the median OS was 9.4 months with FTD/TPI plus bevacizumab versus 7.2 months with FTD/TPI alone (HR 0.67, 95% CI 0.48-0.93), and in patients without a KRASG12 mutation, the median OS was 11.3 versus 7.1 months, respectively (HR 0.59, 95% CI 0.43-0.81). CONCLUSIONS: The presence of a KRASG12 mutation had no detrimental effect on OS among patients treated in SUNLIGHT. The benefit of FTD/TPI plus bevacizumab over FTD/TPI alone was confirmed independently of KRASG12 status.

Efficacy of Chemotherapy Rechallenge Versus Regorafenib or Trifluridine/Tipiracil in Third-Line Setting of Metastatic Colorectal Cancer: A Multicenter Retrospective Comparative Study.

PURPOSE: Metastatic colorectal cancer (mCRC) is a significant global health burden. This retrospective study compared the effectiveness of trifluridine/tipiracil (FTD/TPI), regorafenib, and chemotherapy rechallenge for third-line mCRC treatment. MATERIALS AND METHODS: We reviewed the medical records of 132 patients with mCRC treated with regorafenib, FTD/TPI, or a rechallenge with the initial chemotherapy regimen in a third-line setting from four different institutions. The primary end point was progression-free survival (PFS). Secondary end points were objective response rate and overall survival (OS) across the three treatment approaches. RESULTS: Twenty-nine patients received chemotherapy rechallenge, and 103 received FTD/TPI or regorafenib. Patients' characteristics were comparable, except for a lower number of left-sided primaries and KRAS wild-type tumors in the FTD/TPI-regorafenib group. The median PFS for the entire group was 3.0 months, and the median OS was 13.7 months. Chemotherapy rechallenge has resulted in a median PFS of 3.1 months and a median OS of 21.2 months, compared with 2.9 months (PFS) and 12.6 months (OS) for the FTD/TPI-regorafenib group. Multivariate analyses identified male sex and an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-1 as independent prognostic factors for better PFS, whereas chemotherapy rechallenge, localized stage at diagnosis, and an ECOG PS of 0-1 were significant prognostic factors for better OS. CONCLUSION: This study suggests that chemotherapy rechallenge may provide a survival benefit in the third-line treatment of mCRC. However, patient characteristics, such as sex and ECOG PS, should also be considered in treatment decisions. Further prospective studies are required to confirm our findings.

A Phase II Study of FOLFIRI Plus Ziv-Aflibercept After Trifluridine/Tipiracil Plus Bevacizumab in Patients with Metastatic Colorectal Cancer: WJOG 11018G.

BACKGROUND: Non-inferiority of trifluridine/tipiracil (FTD/TPI) plus bevacizumab (BEV) to irinotecan/fluoropyrimidine plus BEV in metastatic colorectal cancer was investigated in the phase III TRUSTY study, and we conducted a phase II study of FOLFIRI (5-FU+leucovorin+irinotecan) plus zib-aflibercept (AFL) after FTD/TPI plus BEV. However, the TRUSTY study failed during the recruitment of our patients. OBJECTIVE: We present the findings of a phase II study on the efficacy of FOLFIRI plus zib-aflibercept (AFL) after FTD/TPI plus BEV, including clinical results with plasma biomarker analyses. METHODS: This was a multicenter, single-arm, phase II study in patients with metastatic colorectal cancer refractory or intolerant to oxaliplatin, fluoropyrimidine, BEV, and FTD/TPI. The primary endpoint was progression-free survival. Fifteen plasma angiogenesis-associated biomarkers were analyzed using a Luminex® multiplex assay U-kit. RESULTS: Between January 2020 and May 2022, 26 patients (median age, 68 years) from 15 sites were enrolled. The median progression-free survival was 4.9 months (85% confidence interval, 3.4 month-not estimated). The overall response and disease control rates were 8% and 62%, respectively. The median levels of vascular endothelial growth factor-A and placental growth factor, both targets of AFL, were below the measurable limit of 30 pg/mL and 16 pg/mL, respectively. Patients were divided into two groups at the median levels of baseline biomarkers. The progression-free survival did not differ between high and low expressers of placental growth factor (p = 0.7), while it tended to be shorter in those with high levels of osteopontin (p = 0.05), angiopoietin-2 (p = 0.07), and tissue inhibitor of matrix metalloproteinases-1 (p = 0.1). CONCLUSIONS: This study did not meet the primary endpoint. Hence, FOLFIRI plus AFL should not be used after FTD/TPI plus BEV for metastatic colorectal cancer. Further studies are needed to determine factors not targeted by AFL that may affect the efficacy of the treatment. CLINICAL TRIAL REGISTRATION: jRCTs041190100.

Programming sp3 Quantum Defects along Carbon Nanotubes with Halogenated DNA.

Atomic defect color centers in solid-state systems hold immense potential to advance various quantum technologies. However, the fabrication of high-quality, densely packed defects presents a significant challenge. Herein we introduce a DNA-programmable photochemical approach for creating organic color-center quantum defects on semiconducting single-walled carbon nanotubes (SWCNTs). Key to this precision defect chemistry is the strategic substitution of thymine with halogenated uracil in DNA strands that are orderly wrapped around the nanotube. Photochemical activation of the reactive uracil initiates the formation of sp3 defects along the nanotube as deep exciton traps, with a pronounced photoluminescence shift from the nanotube band gap emission (by 191 meV for (6,5)-SWCNTs). Furthermore, by altering the DNA spacers, we achieve systematic control over the defect placements along the nanotube. This method, bridging advanced molecular chemistry with quantum materials science, marks a crucial step in crafting quantum defects for critical applications in quantum information science, imaging, and sensing.

Loop nucleobases-dependent folding of G-quadruplex in normal and cancer cell-mimicking KCl microenvironments.

In this study, the folding of G-quadruplex (G4) from the telomeric DNA sequences having loop nucleobases of different chemical natures, numbers, and arrangements in 10 mM and 100 mM KCl salt conditions mimicking the cancerous and normal KCl salt microenvironments have been investigated. The data suggest that the structure and stability of the G4 are highly dependent on the KCl salt concentration. In general, the conformational flexibility of the folded G4 is higher in KCl salt relevant to cancer than in the normal case for any loop arrangements with the same number of nucleobases. The stability of the G4 decreases with the increase in the number of loop nucleobases for both salt conditions. However, the decrease in the stability of G4 having adenine in the loop region is significantly higher than the case of thymine, particularly more prominent in the KCl salt relevant to the cancer. The topology of the folded G4 and its stability also depend delicately on the permutation of the nucleobases in the loop and the salt concentrations for a particular sequence. The findings indicate that the structure and stability of G4 are noticeably different in KCl salt relevant to physiological and cancer conditions.

Efficacy and Safety of Trifluridine/Tipiracil-Containing Combinations in Colorectal Cancer and Other Advanced Solid Tumors: A Systematic Review.

We performed a systematic literature review to identify and summarize data from studies reporting clinical efficacy and safety outcomes for trifluridine/tipiracil (FTD/TPI) combined with other antineoplastic agents in advanced cancers, including metastatic colorectal cancer (mCRC). We conducted a systematic search on May 29, 2021, for studies reporting one or more efficacy or safety outcome with FTD/TPI-containing combinations. Our search yielded 1378 publications, with 38 records meeting selection criteria: 35 studies of FTD/TPI-containing combinations in mCRC (31 studies second line or later) and 3 studies in other tumor types. FTD/TPI plus bevacizumab was extensively studied, including 19 studies in chemorefractory mCRC. Median overall survival ranged 8.6-14.4 months and median progression-free survival 3.7-6.8 months with FTD/TPI plus bevacizumab in refractory mCRC. Based on one randomized and several retrospective studies, FTD/TPI plus bevacizumab was associated with improved outcomes compared with FTD/TPI monotherapy. FTD/TPI combinations with chemotherapy or other targeted agents were reported in small early-phase studies; preliminary data indicated higher antitumor activity for certain combinations. Overall, no safety concerns existed with FTD/TPI combinations; most common grade ≥ 3 adverse event was neutropenia, ranging 5%-100% across all studies. In studies comparing FTD/TPI combinations with monotherapy, grade ≥ 3 neutropenia appeared more frequently with combinations (29%-67%) vs. monotherapy (5%-41%). Discontinuation rates due to adverse events ranged 0%-11% for FTD/TPI plus bevacizumab and 0%-17% with other combinations. This systematic review supports feasibility and safety of FTD/TPI plus bevacizumab in refractory mCRC. Data on non-bevacizumab FTD/TPI combinations remain preliminary and need further validation.

Comparative Efficacy and Safety of Standard and Biweekly Trifluridine/Tipiracil Regimen in Patients With Colorectal Cancer.

BACKGROUND/AIM: Trifluridine/tipiracil (FTD/TPI) is used to treat metastatic colorectal cancer (mCRC). Since the standard regimen of FTD/TPI features a complex dosing schedule and frequently results in severe hematological toxicities, a simplified regimen has emerged, in which FTD/TPI is orally administered biweekly. However, the survival benefits and potential adverse events associated with the biweekly FTD/TPI regimen have not been fully evaluated in previous reports. Therefore, in this study, the differences in efficacy and safety between the standard and biweekly FTD/TPI regimens were retrospectively investigated in patients with mCRC. PATIENTS AND METHODS: Data from 90 patients who received FTD/TPI for mCRC were extracted from the electronic medical records at the Osaka University Hospital. According to the inclusion and exclusion criteria, 85 of the 90 patients were enrolled in the study. We compared patient characteristics, overall survival (OS), progression-free survival (PFS), and adverse events between the standard (n=56) and biweekly groups (n=29). RESULTS: The biweekly group exhibited prolonged OS and PFS compared to patients in the standard group. Multivariate analysis for OS and PFS demonstrated that the biweekly regimen was the only significant factor that affected OS, and not PFS (HR=0.561, p=0.049). Kaplan-Meier analysis indicated that neutropenia (grade ≥3) in the biweekly group was significantly prolonged compared to the standard group (p=0.012). However, there were no significant differences in adverse events between the two groups (p>0.999). CONCLUSION: The biweekly FTD/TPI regimen, compared to the standard regimen, should enhance both OS and PFS in patients with mCRC without escalating any adverse event.

Efficacy and safety of trifluridine/tipiracil (TAS-102) in patients with metastatic colorectal cancer: a systematic review and meta-analysis

Objectives The purpose of this meta-analysis is to evaluate the efficacy and safety of TAS-102 in treating metastatic colorectal cancer (mCRC) using the most recent data available. Methods The literature on the efficacy and safety of TAS-102 versus placebo and/or best supportive care (BSC) in mCRC was obtained through a systematic search of PubMed, Embase, and Web of Science databases through January 2023. Identify the included literature and extract pertinent data, such as the overall survival (OS), progression-free survival (PFS), time to treatment failure (TTF), disease control rate (DCR), incidence of adverse events (AEs) and serious adverse events (SAEs). Results There were eight eligible articles that included 2903 patients (1964 TAS-102 versus 939 Placebo and/or BSC). In this meta-analysis, TAS-102 treatment resulted in longer OS, PFS, TTF, and higher DCR in patients with mCRC versus placebo and/or BSC. TAS-102 improved OS and PFS in subgroup analyses of mCRC patients with KRAS wild-type and KRAS mutant-type. In addition, TAS-102 did not increase the incidence of serious adverse events. Conclusion TAS-102 can enhance the prognosis of mCRC patients whose standard therapy has failed, regardless of KRAS mutation status, and its safety is acceptable (AU)