Search

Ribonucleotide reductases (RNRs) are essential enzymes that catalyze the de novo transformation of nucleoside 5- di(tri)phosphates [ND(T)Ps, where N is A, U, C, or G] to their corresponding deoxynucleotides. Despite the diversity of factors required for function and the low sequence conservation across RNRs, a unifying apparatus consolidating RNR activity is explored. We combine aspects of the protein subunit simplicity of class II RNR with a modified version of Escherichia coli class la photoRNRs that initiate radical chemistry with light to engineer a mimic of a class II enzyme. The design of this RNR involves fusing a truncated form of the active site containing α subunit with the functionally important C- terminal tail of the radical- generating β subunit to render a chimeric RNR. Inspired by a recent cryo- EM structure, a [Re] photooxidant is located adjacent to Y356[β], which is an essential component of the radical transport pathway in class I RNRs. Combination of this RNR photochimera with cytidine diphosphate (CDP), adenosine triphosphate (ATP), and light resulted in the generation of Y356• along with production of deoxycytidine diphosphate (dCDP) and cytosine. The photoproducts reflect an active site chemistry consistent with both the consensus mechanism of RNR and chemistry observed when RNR is inactivated by mechanism- based inhibitors in the active site. The enzymatic activity of the RNR photochimera in the absence of any β metallocofactor highlights the adaptability of the 10- stranded αβ barrel finger loop to support deoxynucleotide formation and accommodate the design of engineered RNRs. [ABSTRACT FROM AUTHOR]

Host-directed therapy (HDT) is an emerging approach to overcome antimicrobial resistance in pathogenic microorganisms. Specifically, HDT targets host-encoded factors required for pathogen replication and survival without interfering with microbial growth or metabolism, thereby eliminating the risk of resistance development. By applying HDT and a drug repurposing approach, we demonstrate that (R)-DI-87, a clinical-stage anticancer drug and potent inhibitor of mammalian deoxycytidine kinase (dCK), mitigates Staphylococcus aureus abscess formation in organ tissues upon invasive bloodstream infection. Mechanistically, (R)-DI- 87 shields phagocytes from staphylococcal death-effector deoxyribonucleosides that target dCK and the mammalian purine salvage pathway-apoptosis axis. In this manner, (R)-DI- 87- mediated protection of immune cells amplifies macrophage infiltration into deep-seated abscesses, a phenomenon coupled with enhanced pathogen control, ameliorated immunopathology, and reduced disease severity. Thus, pharmaceutical blockade of dCK represents an advanced anti-infective intervention strategy against which staphylococci cannot develop resistance and may help to fight fatal infectious diseases in hospitalized patients. [ABSTRACT FROM AUTHOR]

Bladder cancer (BCa) research relying on Omics approaches has increased over the last few decades, improving the understanding of BCa pathology and contributing to a better molecular classification of BCa subtypes. To gain further insight into the molecular profile underlying the development of BCa, a systematic literature search was performed in PubMed until November 2023, following the PRISMA guidelines. This search enabled the identification of 25 experimental studies using mass spectrometry or nuclear magnetic resonance-based approaches to characterize the metabolite signature associated with BCa. A total of 1562 metabolites were identified to be altered by BCa in different types of samples. Urine samples displayed a higher likelihood of containing metabolites that are also present in bladder tumor tissue and cell line cultures. The data from these comparisons suggest that increased concentrations of L-isoleucine, L-carnitine, oleamide, palmitamide, arachidonic acid and glycoursodeoxycholic acid and decreased content of deoxycytidine, 5-aminolevulinic acid and pantothenic acid should be considered components of a BCa metabolome signature. Overall, molecular profiling of biological samples by metabolomics is a promising approach to identifying potential biomarkers for early diagnosis of different BCa subtypes. However, future studies are needed to understand its biological significance in the context of BCa and to validate its clinical application. [ABSTRACT FROM AUTHOR]

The main challenge in using gemcitabine, a nucleoside analogue anti-cancer, includes resistance of some patients to this compound due to the genetic mutations on deoxycytidine kinase (dCK) that are found in a fraction of the human population. Here, we investigated the dynamics behavior and ligand binding properties of the wild type (WT) dCK and its characterized double mutant using a combination of bioinformatics tools and molecular dynamics (MD) simulation studies. Root-mean-square deviation (RMSD) values of the WT and mutant enzyme in complex with both ligands (deoxycytidine/gemcitabine) demonstrated that the WT enzyme forms a more stable complex with gemcitabine, as compared with its natural ligand (deoxycytidine). However, the stability of the double mutant-deoxycytidine complex is greater, when compared with gemcitabine. It was also found that Arg131 as a critical residue can affect the binding pattern of the enzyme to ligands in a manner that the WT enzyme can interact with both ligands, while, the mutant enzyme cannot establish efficient interaction with gemcitabine, and shows high affinity to deoxycytidine. These data together indicate that gemcitabine can interact with the WT enzyme in a competitive manner, while double mutant can be considered as a resistant variant against gemcitabine. The interaction of anti-cancer gemcitabine with deoxycytidine kinase (dCK) was compared with its natural analogue; deoxycytidine. The dynamics behavior of the representative drug-resistant mutant of deoxycytidine kinase (dCK) was investigated in comparison with the wild type enzyme. The results of this study explain the mechanism of resistance of resistant variant against gemcitabine. [ABSTRACT FROM AUTHOR]

Rationale: Cytosine and its conjugates are prone to form protonated, triply‐bonded dimers. Therefore, the nucleic‐acid cytosine‐rich sequence forms the four‐stranded noncanonical secondary structure known as the intercalated motif (i‐motif). This process has resulted in studies on cytosine protonated dimers. This communication focuses on the protonated dimers of cytosine and its nucleoside using the survival yield (SY) method and quantum mechanics calculations. Methods: To obtain the precursor ion fragmentation curve, the plot of SY against Ecomδ, the product ion spectra of the protonated dimers were obtained using a Waters/Micromass Q‐TOF Premier mass spectrometer. Quantum mechanics calculations were performed using GAUSSIAN 16, and full geometry optimizations and energy calculations were performed within the density functional theory framework at B3LYP/6‐31G(d,p). Results: The precursor ion fragmentation curve allowed the rating of the gas‐phase stabilities of the analyzed protonated dimers. Substitution of sugar moiety at N1 cytosine atom decreased the gas‐phase stabilities of the protonated dimers. The deoxycytidine dimer was found to be more stable than the cytidine dimer and cytidine–deoxycytidine dimer. Quantum chemical calculations indicated that cytosine aminohydroxy tautomer may be involved in the formation of protonated cytosine–cytosine nucleoside dimers but not in the formation of cytosine dimers. Conclusions: The results obtained for nucleoside dimers indicated that the SY method may reflect the i‐motif stabilities observed under physiological conditions. Therefore, the analysis of other protonated dimers of variously substituted cytosine–cytosine nucleoside using the SY method may be important to study the effect of cytosine substitution on the i‐motif stabilities. Cytosine tautomer containing C2‐OH... N(2H)‐C4 moiety may be involved in the formation of protonated cytosine–cytosine nucleoside dimers. [ABSTRACT FROM AUTHOR]

The self-digestive solution (SDS) of the biocontrol bacterium Lysobacter enzymogenes LE16 shows strong antagonistic activities against multiple soil-borne phytopathogens but the positive evidence of this bacterium against plant foliar disease is still scanty. Thus, laboratory, greenhouse, and field experiments were carried out to estimate the efficacies of SDS, S-SDS (stored at room temperature for 12 months), and H-SDS (heated at 100°C for 30 min) against plant powdery mildew. This bacterium produced hydrolases (phosphatase, protease, lysozyme, chitinase, and β-1,3-glucanase) that degrade pathogen cell components and siderophores that compete for iron with phytopathogens. The top five antimicrobial metabolites identified in SDS were pyroglutamic acid, deoxycytidine, pyrrole-2-carboxylic acid, 13-oxo-9,11-tridecadienoic acid, and 3'-amino-3'-deoxythimidine. Among them, pyroglutamic acid may play a vital role in powdery mildew control. As a result, SDS, S-SDS, and H-SDS strongly inhibited the conidial germination of Erysiphe cichoracearum and Sphaerotheca fuliginea. The application of SDS significantly increased the activity of antioxidant enzymes in crop leaves and effectively controlled tobacco and cucumber powdery mildew in the greenhouse and the field. Therefore, L. enzymogenes LE16 can effectively control powdery mildew. The underlying mechanisms may be attributed to the induction of plant systemic resistance and the production of antifungal substances. [ABSTRACT FROM AUTHOR]

Deoxycytidine analogues (dCas) are widely used for the treatment of malignant diseases. They are commonly inactivated by cytidine deaminase (CDD), or by deoxycytidine monophosphate deaminase (dCMP deaminase). Additional metabolic pathways, such as phosphorylation, can substantially contribute to their (in)activation. Here, a new technique for the analysis of these pathways in cells is described. It is based on the use of 5-ethynyl 2′-deoxycytidine (EdC) and its conversion to 5-ethynyl 2′-deoxyuridine (EdU). Its use was tested for the estimation of the role of CDD and dCMP deaminase in five cancer and four non-cancer cell lines. The technique provides the possibility to address the aggregated impact of cytidine transporters, CDD, dCMP deaminase, and deoxycytidine kinase on EdC metabolism. Using this technique, we developed a quick and cheap method for the identification of cell lines exhibiting a lack of CDD activity. The data showed that in contrast to the cancer cells, all the non-cancer cells used in the study exhibited low, if any, CDD content and their cytidine deaminase activity can be exclusively attributed to dCMP deaminase. The technique also confirmed the importance of deoxycytidine kinase for dCas metabolism and indicated that dCMP deaminase can be fundamental in dCas deamination as well as CDD. Moreover, the described technique provides the possibility to perform the simultaneous testing of cytotoxicity and DNA replication activity. [ABSTRACT FROM AUTHOR]

Introduction: Since the beginning of the SARS-CoV-2 pandemic in December 2019 multiple metabolomics studies have proposed predictive biomarkers of infection severity and outcome. Whilst some trends have emerged, the findings remain intangible and uninformative when it comes to new patients. Objectives: In this study, we accurately quantitate a subset of compounds in patient serum that were found predictive of severity and outcome. Methods: A targeted LC–MS method was used in 46 control and 95 acute COVID-19 patient samples to quantitate the selected metabolites. These compounds included tryptophan and its degradation products kynurenine and kynurenic acid (reflective of immune response), butyrylcarnitine and its isomer (reflective of energy metabolism) and finally 3′,4′-didehydro-3′-deoxycytidine, a deoxycytidine analogue, (reflective of host viral defence response). We subsequently examine changes in those markers by disease severity and outcome relative to those of control patients' levels. Results & conclusion: Finally, we demonstrate the added value of the kynurenic acid/tryptophan ratio for severity and outcome prediction and highlight the viral detection potential of ddhC. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is an autoimmune disease driven by lymphocyte activation against myelin autoantigens in the central nervous system leading to demyelination and neurodegeneration. The deoxyribonucleoside salvage pathway with the rate‐limiting enzyme deoxycytidine kinase (dCK) captures extracellular deoxyribonucleosides for use in intracellular deoxyribonucleotide metabolism. Previous studies have shown that deoxyribonucleoside salvage activity is enriched in lymphocytes and required for early lymphocyte development. However, specific roles for the deoxyribonucleoside salvage pathway and dCK in autoimmune diseases such as MS are unknown. Here we demonstrate that dCK activity is necessary for the development of clinical symptoms in the MOG35–55 and MOG1–125 experimental autoimmune encephalomyelitis (EAE) mouse models of MS. During EAE disease, deoxyribonucleoside salvage activity is elevated in the spleen and lymph nodes. Targeting dCK with the small molecule dCK inhibitor TRE‐515 limits disease severity when treatments are started at disease induction or when symptoms first appear. EAE mice treated with TRE‐515 have significantly fewer infiltrating leukocytes in the spinal cord, and TRE‐515 blocks activation‐induced B and T cell proliferation and MOG35–55‐specific T cell expansion without affecting innate immune cells or naïve T and B cell populations. Our results demonstrate that targeting dCK limits symptoms in EAE mice and suggest that dCK activity is required for MOG35–55‐specific lymphocyte activation‐induced proliferation. [ABSTRACT FROM AUTHOR]

Simple Summary: Colorectal cancer is the third most common cancer worldwide. The treatment of the advanced stages is based on poly-chemotherapies, including oxaliplatin. However, the development of resistance to chemotherapy is observed in 50% of cases, leading to treatment failures. A better understanding of the resistance mechanisms is therefore crucial to improve treatment efficiency and patient survival. In our previous work, showed that ROS production and the p38 MAPK pathway were strongly involved in resistance to oxaliplatin. In this study, we tested several chemotherapies and observed that only gemcitabine efficiently treated oxaliplatin-resistant cancer cells. Indeed, gemcitabine was able to induce apoptosis by inhibiting both the Akt and p38 MAPK pathways. Taken together, our results show that gemcitabine could be an interesting therapeutic option for patients with oxaliplatin-resistant tumors. Resistance to treatments is one of the leading causes of cancer therapy failure. Oxaliplatin is a standard chemotherapy used to treat metastatic colorectal cancer. However, its efficacy is greatly reduced by the development of resistances. In a previous study, we deciphered the mechanisms leading to oxaliplatin resistance and highlighted the roles played by ROS production and the p38 MAPK pathway in this phenomenon. In this report, we studied the effects of different chemotherapy molecules on our oxaliplatin-resistant cells to identify alternative treatments. Among all the studied molecules, gemcitabine was the only one to present a major cytotoxic effect on oxaliplatin-resistant cancer cells both in vivo and in vitro. However, the combination of oxaliplatin and gemcitabine did not present any major interest. Indeed, the study of combination efficiency using Chou and Talalay's method showed no synergy between oxaliplatin and gemcitabine. Using PamGene technology to decipher gemcitabine's effects on oxaliplatin-resistant cells, we were able to show that gemcitabine counteracts chemoresistance by strongly inhibiting the Akt and src/p38 MAPK pathways, leading to apoptosis induction and cell death. In view of these results, gemcitabine could be an interesting alternative therapy for patients with colorectal cancer not responding to oxaliplatin-based protocols such as FOLFOX. [ABSTRACT FROM AUTHOR]

Background: This randomised phase II/III trial aimed to determine whether perioperative chemotherapy with gemcitabine plus docetaxel (GD) is non-inferior to the standard Adriamycin plus ifosfamide (AI) in terms of overall survival (OS) in patients with soft tissue sarcoma (STS).Methods: Patients with localised high-risk STS in the extremities or trunk were randomised to receive AI or GD. The treatments were repeated for three preoperative and two postoperative courses. The primary endpoint was OS.Results: Among 143 enrolled patients who received AI (70 patients) compared to GD (73 patients), the estimated 3-year OS was 91.4% for AI and 79.2% for GD (hazard ratio 2.55, 95% confidence interval: 0.80-8.14, P = 0.78), exceeding the prespecified non-inferiority margin in the second interim analysis. The estimated 3-year progression-free survival was 79.1% for AI and 59.1% for GD. The most common Grade 3-4 adverse events in the preoperative period were neutropenia (88.4%), anaemia (49.3%), and febrile neutropenia (36.2%) for AI and neutropenia (79.5%) and febrile neutropenia (17.8%) for GD.Conclusions: Although GD had relatively mild toxicity, the regimen-as administered in this study-should not be considered a standard treatment of perioperative chemotherapy for high-risk STS in the extremities and trunk.Clinical Trial Registration: jRCTs031180003. [ABSTRACT FROM AUTHOR]

Background: Gemcitabine and cisplatin has limited benefit as treatment for advanced biliary tract cancer (BTC). The addition of an anti-programmed death receptor (PD-1)/PD-ligand (L1) antibody to either systemic chemotherapy or anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4) antibody has shown benefit in multiple solid tumors.Methods: In this phase 2 trial, patients 18 years or older with advanced BTC without prior systemic therapy and Eastern Cooperative Oncology Group Performance Status 0-1 were randomized across six academic centers. Patients in Arm A received nivolumab (360 mg) on day 1 along with gemcitabine and cisplatin on days 1 and 8 every 3 weeks for 6 months followed by nivolumab (240 mg) every 2 weeks. Patients in Arm B received nivolumab (240 mg) every 2 weeks and ipilimumab (1 mg/kg) every 6 weeks.Results: Of 75 randomized patients, 68 received therapy (Arm A = 35, Arm B = 33); 51.5% women with a median age of 62.5 years. The observed primary outcome of 6-month progression-free survival (PFS) rates in the evaluable population was 59.4% in Arm A and 21.2% in Arm B. The median PFS and overall survival (OS) in Arm A were 6.6 and 10.6 months, and in Arm B 3.9 and 8.2 months, respectively, in patients who received any treatment. The most common treatment-related grade 3 or higher hematologic adverse event was neutropenia in 34.3% (Arm A) and nonhematologic adverse events were fatigue (8.6% Arm A) and elevated transaminases (9.1% Arm B).Conclusions: The addition of nivolumab to chemotherapy or ipilimumab did not improve 6-month PFS. Although median OS was less than 12 months in both arms, the high OS rate at 2 years in Arm A suggests benefit in a small cohort of patients. [ABSTRACT FROM AUTHOR]

Altogether six tautomers of cytosine and three tautomers of cytidine and deoxycytidine are studied theoretically in the gas phase and in a microhydrated environment. Their structures are optimized at MP2/6–31 + G(d,p) level. The relative energies of the isolated and the hydrated tautomers included the correction to higher correlation energy terms evaluated at the SCS‐MP2, MP4, and CCSD(T) levels. The free energies at 298 K and higher temperatures are based on the above‐mentioned relative energies and temperature‐dependent enthalpy terms and entropies evaluated at the MP2/6–31 + G(d,p) level. Theoretical predictions for the coexistence of five species for cytosine in the gas phase (canonical, trans‐ and cis‐enol‐amino, trans‐ and cis‐imino‐oxo forms) fully agree with recent experimental results. Five‐hydrated cytosine tautomeric forms of are investigated at CPCM/SCS‐MP2/6–31 + G(d,p) level to evaluate the interconversion barriers between them and to explain the coexistence, experimentally proven, of two amino‐oxo and one imino‐oxo tautomers of cytosine in aqueous solution. The presence of coordinated water molecules acting as a catalyst make the tautomerization processes quite easier. It appeared clear from the obtained data that the influence of the hydrogen‐bonded water molecules as well as the introduction of solvent effects in reducing the height of the tautomerization barriers for these five‐hydrated systems is quite substantial. Similar results are obtained for the tri‐hydrated cytidine and the 2‐deoxycytidine tautomeric forms. In aqueous solution of cytidine, syn‐ and syn‐clinal‐conformers оf the amino‐oxo tautomer should coexist with small amounts of syn‐ and syn‐clinal conformers оf imino‐oxo tautomer. For 2‐deoxycytidine an equilibrium has been found to exist between the syn‐ and anti‐conformers of the amino‐oxo and the imino‐oxo tautomers. The water‐assisted proton transfer reactions released through asynchronous concerted mechanism and the conformation of the sugar ring in nucleosides does not change during the tautomerization. [ABSTRACT FROM AUTHOR]

Background and Objectives: Colorectal cancer (CRC) is a malignant tumor with an extremely high incidence rate worldwide. This study explores the influence of mindfulness-based stress reduction (MBSR) in the care of patients with CRC undergoing bevacizumab (BVZ) plus XELOX chemotherapy, aiming at providing reliable reference and guidance for further improving their rehabilitation and prognosis.Methods: Between January 2019 and March 2020, 88 patients with CRC admitted consecutively to Jiangsu Cancer Hospital in China were enrolled in the study. Of them, 42 patients receiving BVZ plus XELOX chemotherapy, conventional care and MBSR intervention were assigned to the intervention group, and the remaining 46 patients receiving XELOX chemotherapy and conventional care were included in the control group. Clinical efficacy, safety and improvement in functional status were compared. Patients' psychological state, treatment compliance and self-care ability were evaluated. Finally, prognostic quality of life (QoL) was recorded at 1-year follow-up.Results: The overall response rate and incidence of adverse events in the intervention group were not different in the control group, but the total control rate and improvement rate in the intervention group were higher. After treatment, Sedation-Agitation Scale (SAS) and Self-Rating Depression Scale (SDS) scores in the intervention group were decreased, compliance and self-care ability were improved, all of which were better than in the control group. Prognostic follow-up showed that the QoL in the intervention group was also higher than in the control group.Conclusions: The combined use of BVZ in XELOX-based chemotherapy can improve the clinical outcome and functional status of patients with CRC. In addition, MBSR intervention implemented during chemotherapy can effectively optimize patients' psychological state and treatment compliance, strengthen their self-care ability and improve their prognostic QoL. [ABSTRACT FROM AUTHOR]

Simple Summary: We investigated the effect of combinational use of PARP inhibitors on cytotoxicity of 5-aza-dC in human cancer cell lines. The combinational treatment of 5-aza-dC and PARP inhibitor PJ-34 exhibited a stronger cytotoxicity compared with their treatment alone in blood cancer HL-60, U937, and colon cancer HCT116 and RKO cells. In microarray analysis, combinational treatment with PJ-34 and 5-aza-dC caused different broad changes in gene expression profiles compared with their single treatments in both HCT116 and RKO cells. The profiles of reactivation of silenced genes were also different in combination of PJ-34 and 5-aza-dC and their single treatments. The results suggest that a combination of 5-aza-dC and PARP inhibitor may be useful by inducing distinct transcriptional profile changes. Poly(ADP-ribose) polymerase (PARP) is involved in DNA repair and chromatin regulation. 5-Aza-2′-deoxycytidine (5-aza-dC) inhibits DNA methyltransferases, induces hypomethylation, blocks DNA replication, and causes DNA single strand breaks (SSBs). As the PARP inhibitor is expected to affect both DNA repair and transcriptional regulations, we investigated the effect of combinational use of PARP inhibitors on cytotoxicity of 5-aza-dC in human cancer cell lines. The combinational treatment of 5-aza-dC and PARP inhibitor PJ-34 exhibited a stronger cytotoxicity compared with their treatment alone in blood cancer HL-60, U937, and colon cancer HCT116 and RKO cells. Treatment with 5-aza-dC but not PJ-34 caused SSBs in HCT116 cell lines. Global genome DNA demethylation was observed after treatment with 5-aza-dC but not with PJ-34. Notably, in microarray analysis, combinational treatment with PJ-34 and 5-aza-dC caused dissimilar broad changes in gene expression profiles compared with their single treatments in both HCT116 and RKO cells. The profiles of reactivation of silenced genes were also different in combination of PJ-34 and 5-aza-dC and their single treatments. The results suggest that the combinational use of 5-aza-dC and PARP inhibitor may be useful by causing distinct transcriptional profile changes. [ABSTRACT FROM AUTHOR]

Mantled is a kind of fruit abnormality in oil palm and can cause serious yield loss of palm oil. It was reported that mantled phenotype could be resulted from the application of plant growth regulators (e.g. 2, 4-D) during tissue culture. However, the effect of 2, 4-D treatment on the development of mantled variation is still very limited. In this study, based on our present oil palm tissue culture system, the inflorescence explants were treated with different concentrations of 2,4-D at callus induction stage to induce mantled. Along with a known mantled sample as control, all 2,4-D treated samples were detected with an available DNA marker (kDEF1) for mantled identification, the expression of EgDEF1 transcripts (kDEF1 and tDEF1) and the accumulation of mantled related metabolites (deoxycytidine) were then analyzed using transcriptomics and metabolomics analysis. Detection of mantled by kDEF1 marker showed that kDEF1 was detected only in control (mantled) sample whereas none was found in 2,4-D treated samples. Furthermore, transcriptome analysis confirmed that kDEF1 transcript was not presented at all in 2,4-D treated samples. In contrast with earlier reports in mantled samples, tDEF1 was down-regulated and the accumulation of deoxycytidine was increased during callus induction. Therefore, the mantled variation was not identified at DNA, RNA and metabolite levels in 2,4-D treated samples, suggesting that high concentration of 2,4-D may not result in mantled variation during callus induction. However, similar research at embryogenesis stage could be till needed to explore more possibilities. [ABSTRACT FROM AUTHOR]

Background: Gemcitabine (Gem) alone or with Nab-paclitaxel (Gem-Nab) is used as second-line treatment for metastatic pancreatic adenocarcinoma (mPA) after FOLFIRINOX (FFX) failure; however, no comparative data exist. This study evaluates the efficacy and safety of adding Nab-paclitaxel to Gem for mPA after FFX failure.Methods: In this retrospective real-world multicenter study, from 2011 to 2019, patients with mPA receiving Gem-Nab (Gem 1000 mg/m² + Nab 125 mg/m², 3 out of 4 weeks) or Gem alone were included after progression on FFX.Results: A total of 427 patients were included. Patients receiving Gem-Nab had more metastatic sites, peritoneal disease and less PS 2 (24% vs. 35%). After median follow-up of 22 months, Gem-Nab was associated with better disease control rate (DCR) (56% vs. 32%; P < 0.001), progression-free survival (PFS) (3.5 vs. 2.3 months; 95% CI: 0.43-0.65) and overall survival (OS) (7.1 vs. 4.7 months; 95% CI: 0.53-0.86). After multivariate analysis, Gem-Nab and PS 0/1 were associated with better OS and PFS. Grade 3/4 toxicity was more frequent with Gem-Nab (44% vs. 29%).Conclusion: In this study, Gem-Nab was associated with better DCR, PFS and OS compared with Gem alone in patients with mPA after FFX failure, at the cost of higher toxicity. [ABSTRACT FROM AUTHOR]

The ergothioneine transporter ETT (formerly OCTN1; human gene symbol SLC22A4) is a powerful and highly specific transporter for the uptake of ergothioneine (ET). Recently, Sparreboom et al. reported that the ETT would transport nucleosides and nucleoside analogues such as cytarabine and gemcitabine with the highest efficiency. In our assay system, we could not detect any such transport. Subsequently, Sparreboom suggested that the intracellular metabolization of the nucleosides occurs so fast that the original compounds cannot be detected by LC–MS/MS after inward transport. Our current experiments with 293 cells disprove this hypothesis. Uptake of gemcitabine was easily detected by LC–MS/MS measurements when we expressed the Na+/nucleoside cotransporter CNT3 (SLC28A3). Inward transport was 1280 times faster than the intracellular production of gemcitabine triphosphate. The deoxycytidine kinase inhibitor 2-thio-2′-deoxycytidine markedly blocked the production of gemcitabine triphosphate. There was no concomitant surge in intracellular gemcitabine, however. This does not fit the rapid phosphorylation of gemcitabine. Uptake of cytarabine was very slow, but detection by MS was still possible. When the ETT was expressed and incubated with gemcitabine, there was no increase in intracellular gemcitabine triphosphate. We conclude that the ETT does not transport nucleosides. [ABSTRACT FROM AUTHOR]

Cytarabine (Ara-C) is the mainstay of treatment of acute myeloid leukemia (AML), but still, drug resistance and treatment-related toxicities are the main causes of treatment failure. Single nucleotide polymorphisms (SNPs) of the key genes involved in the metabolic pathway of Ara-C have been reported to affect the clinical outcome, so we aimed to investigate the potential association of SNPs of deoxycytidine kinase [DCK] 201C>T (rs2306744), DCK 360C>G (rs377182313) and cytidine deaminase (CDA) 79A>C (rs2072671) genes in adult Egyptian AML patients with the outcome. Genotyping of the studied SNPs was tested using PCR- RFLP technique in 142 adult de novo AML patients who received standard induction chemotherapy based on cytarabine and doxorubicin (3+7 protocol). The median (range) age of our patients was 38 (20-60) years. The studied SNPs genotypes had no significant influence on treatment response on day 28 of induction therapy. DCK 201 heterozygous CT genotype, DCK 201-T allele, [DCK 201(CC)/DCK 360(CC)/CDA 79(AC)] combination as well as hepatological, nephrological, neurological and hematological toxicities were independent prognostic markers on the survival of our AML patients. Nucleophosmin mutation was associated with the poor prognostic variant DCK 201-T and CDA 79-A alleles. Fms-like tyrosine3 kinase internal tandem duplication (FLT3-ITD) mutation was associated with the wild AA genotype of CDA 79A>C polymorphism, while FLT3-tyrosine kinase domain (TKD) mutation was associated with variant DCK360-G allele. These findings support the idea that the studied SNPs can be used as prognostic markers helping in tailored treatment for AML patients. [ABSTRACT FROM AUTHOR]

Background: There is paucity of investigations into immunotherapy or targeted therapy for postoperative locally recurrent pancreatic cancer. We aimed to assess the efficacy of stereotactic body radiotherapy (SBRT) plus pembrolizumab and trametinib in these patients.Methods: In this open-label, randomised, controlled, phase 2 study, participants were recruited from Changhai Hospital affiliated to the Naval Medical University, Shanghai, China. Eligible patients were aged 18 years or older with histologically confirmed pancreatic ductal adenocarcinoma characterised by mutant KRAS and positive immunohistochemical staining of PD-L1, Eastern Cooperative Oncology Group performance status of 0 or 1, and documented local recurrence after surgery followed by chemotherapy (mFOLFIRINOX [ie, 5-fluorouracil, oxaliplatin, irinotecan, and folinic acid] or 5-fluorouracil). Eligible participants were randomly assigned (1:1) using an interactive voice or web response system, without stratification, to receive SBRT with doses ranging from 35-40 Gy in five fractions, intravenous pembrolizumab 200 mg once every 3 weeks, and oral trametinib 2 mg once daily or SBRT (same regimen) and intravenous gemcitabine (1000 mg/m2) on day 1 and 8 of a 21-day cycle for eight cycles until disease progression, death, unacceptable toxicity, or consent withdrawal. The primary endpoint was overall survival in the intention-to-treat population. Safety was assessed in the as-treated population in all participants who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, NCT02704156, and is now complete.Findings: Between Oct 10, 2016, and Oct 28, 2017, 198 patients were screened, of whom 170 patients were enrolled and randomly assigned to receive SBRT plus pembrolizumab and trametinib (n=85) or SBRT plus gemcitabine (n=85). As of the clinical cutoff date (Nov 30, 2020), median follow-up was 13·1 months (IQR 10·2-17·1). Median overall survival was 14·9 months (12·7-17·1) with SBRT plus pembrolizumab and trametinib and 12·8 months (95% CI 11·2-14·4) with SBRT plus gemcitabine (hazard ratio [HR] 0·69 [95% CI 0·51-0·95]; p=0·021). The most common grade 3 or 4 adverse effects were increased alanine aminotransferase or aspartate aminotransferase (ten [12%] of 85 in SBRT plus pembrolizumab and trametinib group vs six [7%] of 85 in SBRT plus gemcitabine group), increased blood bilirubin (four [5%] vs none), neutropenia (one [1%] vs nine [11%]), and thrombocytopenia (one [1%] vs four [5%]). Serious adverse events were reported by 19 (22%) participants in the SBRT plus pembrolizumab and trametinib group and 12 (14%) in the SBRT plus gemcitabine group. No treatment-related deaths occurred.Interpretation: The combination of SBRT plus pembrolizumab and trametinib could be a novel treatment option for patients with locally recurrent pancreatic cancer after surgery. Phase 3 trials are needed to confirm our findings.Funding: Shanghai Shenkang Center and Changhai Hospital.Translation: For the Chinese translation of the abstract see Supplementary Materials section. [ABSTRACT FROM AUTHOR]

Background: No reliable nomogram has been developed until date for predicting the survival in patients with unresectable pancreatic cancer undergoing treatment with gemcitabine plus nab-paclitaxel (GnP) or FOLFIRINOX.Methods: This analysis was conducted using clinical data of Japanese patients with unresectable pancreatic cancer undergoing GnP or FOLFIRINOX treatment obtained from a multicenter study (NAPOLEON study). A Cox proportional hazards model was used to identify the independent prognostic factors. A nomogram to predict 6-, 12-, and 18-month survival probabilities was generated, validated by using the concordance index (C-index), and calibrated by the bootstrapping method. And then, we attempted risk stratification for survival by classifying the patients according to the sum of the scores on the nomogram (total nomogram points).Results: A total of 318 patients were enrolled. A prognostic nomogram was generated using data on the Eastern Cooperative Oncology Group performance status, liver metastasis, serum LDH, serum CRP, and serum CA19-9. The C-indexes of the nomogram were 0.77, 0.72 and 0.70 for 6-, 12-, and 18-month survival, respectively. The calibration plot showed optimal agreement at all points. Risk stratification based on tertiles of the total nomogram points yielded clear separations of the survival curves. The median survival times in the low-, moderate-, and high-risk groups were 15.8, 12.8 and 7.8 months (P<0.05), respectively.Conclusions: Our nomogram might be a convenient and inexpensive tool to accurately predict survival in Japanese patients with unresectable pancreatic cancer undergoing treatment with GnP or FOLFIRINOX, and will help clinicians in selecting appropriate therapeutic strategies for individualized management. [ABSTRACT FROM AUTHOR]

Gemcitabine has been extensively applied in treating various solid tumors. Nonetheless, the clinical performance of gemcitabine is severely restricted by its unsatisfactory pharmacokinetic parameters and easy deactivation mainly because of its rapid deamination, deficiencies in deoxycytidine kinase (DCK), and alterations in nucleoside transporter. On this account, repeated injections with a high concentration of gemcitabine are adopted, leading to severe systemic toxicity to healthy cells. Accordingly, it is highly crucial to fabricate efficient gemcitabine delivery systems to obtain improved therapeutic efficacy of gemcitabine. A large number of gemcitabine pro-drugs were synthesized by chemical modification of gemcitabine to improve its biostability and bioavailability. Besides, gemcitabine-loaded nano-drugs were prepared to improve the delivery efficiency. In this review article, we introduced different strategies for improving the therapeutic performance of gemcitabine by the fabrication of pro-drugs and nano-drugs. We hope this review will provide new insight into the rational design of gemcitabine-based delivery strategies for enhanced cancer therapy. [ABSTRACT FROM AUTHOR]

Purpose: Drug resistance is a serious problem in leukemia therapy. A novel purine nucleoside analogue, nelarabine, is available for the treatment of children with T cell acute lymphoblastic leukemia. We investigated the mechanisms of drug resistance to nelarabine. Methods: Nelarabine-resistant cells were selected by stepwise and continuous exposure to nelarabine using the limiting dilution method in human B and T cell lymphoblastic leukemia cell lines. Expression analysis was performed using real-time polymerase chain reaction, and epigenetic analysis was performed using methylation-specific polymerase chain reaction and chromatin immunoprecipitation. Results: The RNA expression level for deoxycytidine kinase (dCK) was decreased in nelarabine-resistant leukemia cells. There were no differences between the parental and nelarabine-resistant leukemia cells in the methylation status of the promoter region of the dCK gene. In the chromatin immune precipitation assay, decreased acetylation of histones H3 and H4 bound to the dCK promoter was seen in the nelarabine-resistant cells when compared to the parental cells. Furthermore, treatment with a novel histone deacetylase inhibitor, vorinostat, promoted the cytotoxic effect of nelarabine along with increased expression of the dCK gene, and it increased acetylation of both histones H3 and H4 bound to the dCK promoter in nelarabine-resistant leukemia cells. The combination index showed that the effect of nelarabine and vorinostat was synergistic. Conclusion: This study reports that nelarabine with vorinostat can promote cytotoxicity in nelarabine-resistant leukemia cells through epigenetic mechanisms. [ABSTRACT FROM AUTHOR]

The 4S–Ag(I)–C base pair (4S, 3-((2-(methylthio)pyrimidin-4-yl)thio)propane-1,2-diol; C, deoxycytidine) represents the first metal-mediated base pair comprising an S-glycosidic nucleoside analogue. We report here the synthesis of the phosphoramidite suitable for the automated solid-phase synthesis of DNA oligonucleotides containing 4S and its silver(I)-binding ability. The DNA duplexes comprising a 4S:C mispair exhibit a large thermal stabilization upon the addition of one equivalent of silver ions, giving rise to the formation of the above-mentioned silver(I)-mediated base pair. By formally replacing the sulfur atom in the glycosidic bond by an oxygen atom, i.e., by applying 3-((2-(methylthio)pyrimidin-4-yl)oxy)propane-1,2-diol (4 O) as the artificial nucleoside analogue, the participation of this atom as a donor atom in silver(I)-mediated base pairing is shown to be neglectable. Supplemental data for this article is available online at [ABSTRACT FROM AUTHOR]

It has long been debated whether easily reducible azide groups can withstand the conditions of oligonucleotide synthesis by phosphoramidite chemistry. We have synthesized various 2′‐ and 3′‐azido modified nucleosides and immobilized them on controlled pore glass (CPG) to be used as starting material for the synthesis of oligonucleotides (ONs) with 3′‐terminal azide (attached to C2′ or C3′). In a model study, immobilized 3′‐azidoadenosine was used as a starting block for the synthesis of a series of oligodeoxynucleotides (ODNs) of increasing length. Upon synthesis, the ODNs were enzymatically digested into monomers and analyzed by RP‐HPLC. A peak corresponding to 3′‐azidoadenosine was clearly identified in all samples. Quantitative analysis showed that 3′‐azidoadenosine was present in nearly the expected ratio to deoxycytidine, which was used as an internal standard. Most importantly, the ratio remained the same for all three ODNs regardless of their length, demonstrating that a higher number of coupling cycles does not lead to higher degradation of the azide. Thus, 2′‐ or 3′‐azido nucleosides attached to a solid support are excellent starting materials for the synthesis of oligonucleotides with 3′‐terminal azide. [ABSTRACT FROM AUTHOR]

Context: Previous studies have discovered a high expression rate of Mucin 1 (MUC1) in pancreatic cancer tissue, and its abnormal glycosylation causes MUC1 to expose new protein epitopes or glycoantigens.Aims: To investigate the therapeutic effect of drug-loaded gemcitabine polybutylcyanoacrylate nanoparticles coupled with anti-human MUC1 monoclonal antibody (mAb) on human pancreatic cancer cell line and xenografts.Settings and Design: Randomized controlled trial.Materials and Methods: Gemcitabine-loaded nanospheres were prepared by emulsion polymerization; then, the anti-MUC1 mAb coupled with gemcitabine polybutylcyanoacrylate nanoparticles (MUC1-GEM-PBCA-NP) was prepared by chemical cross-linking. Cell-killing rates were detected by MTT assay in in vitro study, and changes in tumor cell cycle and apoptosis after treatment were detected by flow cytometry. Furthermore, in in vivo study, MUC1-GEM-PBCA-NP was injected into nude mice through the tail vein. Gemcitabine-loaded polybutylcyanoacrylate nanoparticles (GEM-PBCA-NP), gemcitabine bulk drug and empty nanoparticles (PBCA-NP), and normal saline blank control groups were established. Finally, data obtained were compared between groups.Results: Compared with the control group, the cell-killing rate of each experimental group was significantly different (P < 0.05) in in vitro study, among which the MUC1-GEM-PBCA-NP group was significantly higher than other groups (P < 0.05). In addition, the apoptosis rate of the MUC1-GEM-PBCA-NP treatment group was significantly higher than that of other groups (P < 0.05). Furthermore, in in vivo study, the tumor inhibition rate of the MUC1-GEM-PBCA-NP treatment group was (68.14% ±1.66%), which was significantly higher than other control groups (P < 0.05). Finally, at the end of the treatment, the average tumor mass of the MUC1-GEM-PBCA-NP treatment group was (471.61 mg ± 12.16 mg), which was significantly lower than those of other control groups (P < 0.05).Conclusions: MUC1-GEM-PBCA-NP could have an excellent inhibitory effect on tumors; thus, requiring further study. [ABSTRACT FROM AUTHOR]

Decitabine (DAC), a DNA methyltransferase (DNMT) inhibitor is a novel anti-cancer drug regulating epigenetic mechanisms. Similar to conventional anti-cancer drugs, drug resistance to DAC also has been reported, resulting in tumor recurrence. Our previous study using colorectal cancer HCT116 cells found the decrease in deoxycytidine kinase (dCK) (activation enzyme of DAC) and the increase in cytidine deaminase (inactivation enzyme of DAC) in acquired DAC-resistant HCT116 (HCT116/DAC) cells. The aim of our study was to clarify the involvement of dCK and CDA in DAC resistance. In order to tackle DAC resistance, it was also examined whether other DNMT inhibitors such as azacytidine (AC) and polyphenols are effective in DAC-resistant cancer cells. When dCK siRNA was transfected into HCT116 cells, IC 50 value of DAC increased by about 74-fold and reached that of HCT116/DAC cells with attenuated dCK. dCK siRNA to HCT116 cells also abolished DNA demethylation effects of DAC. In contrast, CDA siRNA to HCT116 cells did not influence the efficacy of DAC. In addition, CDA siRNA to HCT116/DAC cells with increased CDA did not restore the compromised effects of DAC. These results suggested that attenuated dCK but not increased CDA mainly contributed to DAC resistance. Regarding dCK in HCT116/DAC cells, a point mutation with amino acid substitution was observed while the product size and expression of mRNA coding region did not change, suggesting that dCK protein was decreased by post-transcriptional regulation. AC and polyphenols showed no cross-resistance in HCT116/DAC cells. AC but not polyphenols exerted DNA demethylation effect. Among polyphenols, curcumin (Cur) showed the most synergistic cytotoxicity in combination with AC while DNA demethylation effect of AC was partly maintained. Taken together, combination of AC and Cur would be a promising alternative to tackle DAC resistance mainly due to attenuated dCK. [Display omitted] • Attenuated deoxycytidine kinase mainly contributed to acquired decitabine resistance. • Azacytidine exerted DNA demethylation effect in decitabine-resistant cells. • Azacytidine and curcumin enhanced cytotoxicity in decitabine-resistant cells. [ABSTRACT FROM AUTHOR]

Background: The prognosis of patients with advanced biliary tract cancer who have progressed on gemcitabine plus cisplatin is dismal. We aimed to investigate the efficacy and safety of second-line liposomal irinotecan plus fluorouracil and leucovorin in patients with metastatic biliary tract cancer that has progressed on gemcitabine plus cisplatin.Methods: This multicentre, open-label, randomised, phase 2b (NIFTY) study was done at five academic institutions in South Korea and included patients aged 19 years or older with histologically or cytologically confirmed metastatic biliary tract cancer that had progressed on first-line gemcitabine plus cisplatin and an Eastern Cooperative Oncology Group performance status of 0 or 1. By use of an interactive web-based response system integrated with an electronic data capture system, patients were randomly assigned (1:1) using permuted blocks (block size 4) to receive either intravenous liposomal irinotecan (70 mg/m2 for 90 min) plus intravenous leucovorin (400 mg/m2 for 30 min) and intravenous fluorouracil (2400 mg/m2 for 46 h) every 2 weeks or leucovorin and fluorouracil only every 2 weeks, and were stratified by primary tumour site, previous surgery with curative intent, and participating centre. Study treatment was continued until the patient had disease progression or unacceptable toxicities, or withdrew consent. The primary endpoint was blinded independent central review (BICR)-assessed progression-free survival. The primary endpoint and safety were assessed in the full analysis set and the safety analysis set, respectively, both of which comprised all randomly assigned patients who received at least one dose of the study treatment. This trial is registered with ClinicalTrials.gov, NCT03524508, and enrolment is complete.Findings: Between Sept 5, 2018, and Feb 18, 2020, 193 patients were screened for eligibility, of whom 174 (88 in the liposomal irinotecan plus fluorouracil and leucovorin group and 86 in the fluorouracil plus leucovorin group) were enrolled and included in the full analysis and safety analysis sets. At a median follow-up of 11·8 months (IQR 7·7-18·7), the median BICR-assessed progression-free survival was significantly longer in the liposomal irinotecan plus fluorouracil and leucovorin group (7·1 months, 95% CI 3·6-8·8) than in the fluorouracil and leucovorin group (1·4 months, 1·2-1·5; hazard ratio 0·56, 95% CI 0·39-0·81; p=0·0019). The most common grade 3-4 adverse events were neutropenia (21 [24%] of 88 in the liposomal irinotecan plus fluorouracil and leucovorin group vs one [1%] of 86 in the fluorouracil and leucovorin group) and fatigue or asthenia (11 [13%] vs three [3%]). Serious adverse events occurred in 37 (42%) patients receiving liposomal irinotecan plus fluorouracil and leucovorin and 21 (24%) patients receiving fluorouracil and leucovorin. There were no treatment-related deaths.Interpretation: Adding liposomal irinotecan to fluorouracil and leucovorin significantly improved BICR-assessed progression-free survival in patients with advanced biliary tract cancer. Liposomal irinotecan plus fluorouracil and leucovorin could be considered a standard-of-care second-line therapy for advanced biliary tract cancer.Funding: Servier and HK inno.N Translation: For the Korean translation of the abstract see Supplementary Materials section. [ABSTRACT FROM AUTHOR]

CD73, a cell surface-localized ecto-5'-nucleotidase, is the major enzymatic source of extracellular adenosine. Canonically, it plays multiple roles in cancer-related processes via its metabolite. As a druggable target, clinical trials targeting CD73 in various malignant diseases are currently ongoing. Here, we report the ecto-5'-nucleotidase-independent functions of CD73 in pancreatic ductal adenocarcinoma (PDAC). Our findings support that the elevated expression of CD73 in PDAC cells promotes gemcitabine (GEM) resistance by activating AKT. We discovered that a large amount of intracellular CD73 are localized in the endoplasmic reticulum membrane. Intracellular CD73 physically interacts with major vault protein to activate the SRC-AKT circuit. Troglitazone (TGZ) is a peroxisome proliferator-activated receptor gamma agonist that could inhibit the expression of CD73. The administration of TGZ markedly enhances sensitivity to GEM via downregulating CD73 in PDAC. Our findings support that CD73 could be targeted to overcome chemoresistance in PDAC. [ABSTRACT FROM AUTHOR]

Resistance to cytarabine is an important cause of therapy failure in persons with acute myeloid leukemia (AML). Deoxycytidine kinase, encoded by DCK, catalyzes phosphorylation of cytarabine to cytarabine monophosphate, a necessary step for eventual incorporation of cytarabine triphosphate into DNA and for clinical efficacy. Whether DCK mutations make AML cells resistant to cytarabine is controversial. We studied DCK mutations and messenger RNA (mRNA) concentrations in leukemia cells from 10 subjects with AML who received cytarabine-based therapy and relapsed and in 2 artificially induced cytarabine-resistant AML cell lines. DCK mutations were detected in 4 subjects with AML relapsing after achieving a complete remission and receiving high-dose cytarabine postremission therapy. Most mutations were in exons 4–6 and were not present before therapy. DCK was also mutated in cytarabine-resistant but not parental AML cell lines. DCK mRNA concentrations were significantly decreased in cytarabine-resistant K562 and SHI-1 cells compared with cytarabine-sensitive parental cells. Mutation frequency of DCK and mRNA concentration did not correlate with the extent of cytarabine resistance indicating other factors operate. Overexpression of wild-type DCK restored cytarabine sensitivity to previously resistant leukemia cell lines. Our data contribute to the understanding of cytarabine resistance in persons with AML. [ABSTRACT FROM AUTHOR]

Background: Berzosertib (formerly M6620, VX-970) is a highly potent and selective, first-in-class inhibitor of ataxia telangiectasia and Rad3-related protein kinase (ATR). We assessed multiple ascending doses of berzosertib + gemcitabine ± cisplatin in patients with resistant/refractory advanced solid tumours.Methods: We evaluated the safety, tolerability, pharmacokinetics (PK) and preliminary efficacy of intravenous berzosertib + gemcitabine ± cisplatin using a standard 3 + 3 dose-escalation design. The starting doses were berzosertib 18 mg/m2, gemcitabine 875 mg/m2 and cisplatin 60 mg/m2.Results: Fifty-two patients received berzosertib + gemcitabine and eight received berzosertib + gemcitabine + cisplatin. Four patients receiving berzosertib + gemcitabine had a total of seven dose-limiting toxicities (DLTs) and three receiving berzosertib + gemcitabine + cisplatin had a total of three DLTs. Berzosertib 210 mg/m2 (days 2 and 9) + gemcitabine 1000 mg/m2 (days 1 and 8) Q3W was established as the recommended Phase 2 dose (RP2D); no RP2D was determined for berzosertib + gemcitabine + cisplatin. Neither gemcitabine nor cisplatin affected berzosertib PK. Most patients in both arms achieved a best response of either partial response or stable disease.Conclusions: Berzosertib + gemcitabine was well tolerated in patients with advanced solid tumours and showed preliminary efficacy signs.Clinical Trial Identifier: NCT02157792. [ABSTRACT FROM AUTHOR]

Background: Modified FOLFIRINOX and gemcitabine plus nab-paclitaxel (GEM-NAB) have been recommended as first-line therapies for advanced pancreatic cancer (PC). Due to the lack of evidence to directly compare them, we conducted this network meta-analysis to indirectly compare the effectiveness and toxicity of modified FOLFIRINOX and GEM-NAB.Methods: The eligible retrospective studies on treatments related to modified FOLFIRINOX and GEM-NAB up to 4 April 2020 were searched and assessed. We used the frequentist model to analyze the survival and toxicity data between different treatments. Pooled analysis for overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and events of toxicity were analyzed in this study.Results: Twenty-two studies were involved in this network meta-analysis. The comparisons on OS and PFS showed that modified FOLFIRINOX and GEM-NAB had similar treatment efficacy (OS: 1.13; 95% CI: 0.78-1.63; PFS: HR: 1.19; 95% CI: 0.85-1.67). GEM-NAB was more effective than modified FOLFIRINOX based on the result of ORR (RR: 1.43; 95% CI: 1.04-1.96). Moreover, our analysis showed a similar toxicity profile between modified FOLFIRINOX and GEM-NAB.Conclusions: The current evidence showed that modified FOLFIRINOX and GEM-NAB were similar in survival and toxicity. Many factors should be considered for in the formulation of optimal treatment, and our meta-analysis could provide some guidance to treatment selection in the first-line setting for advanced PC. [ABSTRACT FROM AUTHOR]

Dodecamer duplex DNA containing anomeric (α/β‐d) and enantiomeric (β‐l/β‐d) 2'‐deoxycytidine mismatches was studied with respect to base pair stability in the absence and presence of silver ions. Stable duplexes with silver‐mediated cytosine–cytosine pairs were formed by all anomeric and enantiomeric combinations. Stability changes were observed depending on the composition of the mismatches. Most strikingly, the new silver‐mediated base pair of anomeric α‐d‐dC with enantiomeric β‐l‐dC is superior to the well‐noted β‐d/β‐d‐dC pair in terms of stability. CD spectra were used to follow global helical changes of DNA structure. [ABSTRACT FROM AUTHOR]

Background: Gemcitabine plus platinum as the first-line chemotherapy for cholangiocarcinoma (CCA) has limited efficacy. The aim of this study was to evaluate the effectiveness of modified FOLFIRINOX (mFOLFIRINOX) compared to that of gemcitabine plus oxaliplatin (Gemox) for patients with locally advanced or metastatic CCA.Methods: From January 2016 to December 2019, consecutive patients who were diagnosed with locally advanced or metastatic CCA were treated with either mFOLFIRINOX or Gemox as a first-line chemotherapy. The main endpoint was Progression free survival (PFS). The second endpoints were Overall survival (OS), Disease control rate (DCR) and incidence of severe toxicity (grade 3-4). Tumors were evaluated at baseline and thence every 4-6 weeks. The study was designed and carried out in accordance with the principles of the declaration of Helsinki, approved by the Ethics Committee of Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine (XHEC-D-2020-154) and registered with ClinicalTrials.gov , number NCT04305288 (registration date: 12/03/2020).Results: Of 49 patients in this study, 27 were in the FOLFIRINOX regimen group and 22 in the Gemox regimen group. There were no significant differences between groups in baseline characteristics. The DCR was 77.8% in the mFOLFIRINOX group and 63.5% in the Gemox group. The corresponding median PFS was 9.9 months (95% confidence interval [CI], 7.3-12.4) in the mFOLFIRINOX group versus 6.4 months (95% CI,3.6-9.2, p = 0.040) in the Gemox group. The corresponding median OS was 15.7 months (95% CI, 12.5-19.0) versus 12.0 months (95% CI, 9.3-14.8, p = 0.099). Significantly more grade 3-4 vomiting occurred in the mFOLFIRINOX than the Gemox groups (7 (25.9%) vs 1 (4.5%), p = 0.044).Conclusions: First-line mFOLFIRINOX offered more promising results in patients with advanced or metastatic CCA. [ABSTRACT FROM AUTHOR]

Aim: To explore the role of DNA methylation in the innate immunity of the dental pulp, this study investigated the effect of 5‐aza‐2'‐deoxycytidine (AZA) on lipoteichoic acid (LTA)‐induced cytokine production and related intracellular signalling pathways in human odontoblast‐like cells (hOBs). Methodology: hOBs were cultured and differentiated from human dental pulp tissue, and the odontoblastic phenotype of the cells was detected using immunofluorescence, qRT‐PCR and Western blotting. hOBs were pretreated with AZA and then stimulated with 10 μg mL−1 LTA. The levels of 42 cytokines related to immunity and inflammation were examined using a cytokine antibody array and verified using qRT‐PCR and ELISA. The effect of AZA on the LTA‐induced NF‐κB and MAPK signalling pathways was explored using Western blotting. The cells were treated with the specific NF‐κB inhibitor PDTC and MAPK inhibitors (the ERK inhibitor U0126, the p38 inhibitor SB203580, and the JNK inhibitor SP600125) to further confirm the role of the signalling pathways in LTA‐treated hOBs. DNA immunoprecipitation–PCR was used to examine the dynamic methylation status of the gene promoters of myeloid differentiation primary response 88 (MyD88) and tumour necrosis factor receptor‐associated factor 6 (TRAF6) in the LTA‐induced hOBs. Statistical analyses of the differences between two groups were performed using Student's t‐test. One‐way analysis of variance (anova) or repeated‐measures anova with a post hoc Dunnett's test was used to assess the differences between multiple sets of data. P < 0.05 was considered to be statistically significant. Results: The odontoblastic markers were significantly higher in hOBs than those in human dental pulp cells (hDPCs) (P < 0.05). According to the cytokine antibody array results, hOBs pretreated with AZA had significantly increased production of several inflammatory cytokines (P < 0.05), in which the expression levels of IL‐6 and IL‐8 were the most dramatically increased upon LTA stimulation (P < 0.01). Furthermore, AZA resulted in the significant upregulation of p‐IKKα/β, p‐IκBα, p‐p65, p‐p38 and p‐ERK in LTA‐stimulated hOBs (P < 0.01). Treatment with the NF‐κB pathway inhibitor suppressed both IL‐6 and IL‐8 expression (P < 0.05), whereas inhibitors of the MAPK pathway (SB203580 and SP600125) did not. In LTA‐treated hOBs, AZA significantly increased the expression levels of TRAF6 and MyD88 (P < 0.05). AZA induced MyD88 promoter hypomethylation but did not affect TRAF6 methylation. Conclusion: AZA regulated the LTA‐induced inflammatory response through the NF‐κB signal pathway in hOBs. This study highlights the important role of DNA methylation in the immunity defence of odontoblasts during the dental pulp immunity response to caries. [ABSTRACT FROM AUTHOR]

KRAS mutation is associated with the progression and growth of pancreatic cancer and contributes to chemo-resistance, which poses a significant clinical challenge in pancreatic cancer. Here, we developed a RT22-ep59 antibody (Ab) that directly targets the intracellularly activated GTP-bound form of oncogenic KRAS mutants after it is internalized into cytosol by endocytosis through tumor-associated receptor of extracellular epithelial cell adhesion molecule (EpCAM) and investigated its synergistic anticancer effects in the presence of gemcitabine in pancreatic cancer. We first observed that RT22-ep59 specifically recognized tumor-associated EpCAM and reached the cytosol by endosomal escape. In addition, the anticancer effect of RT22-ep59 was observed in the high-EpCAM-expressing pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells, but it had little effect on the low-EpCAM-expressing pancreatic cancer cells. Additionally, co-treatment with RT22-ep59 and gemcitabine synergistically inhibited cell viability, migration, and invasion in 3D-cultures and exhibited synergistic anticancer activity by inhibiting the RAF/ERK or PI3K/AKT pathways in cells with high-EpCAM expression. In an orthotopic mouse model, combined administration of RT22-ep59 and gemcitabine significantly inhibited tumor growth. Furthermore, the co-treatment suppressed cancer metastasis by blocking EMT signaling in vitro and in vivo. Our results demonstrated that RT22-ep59 synergistically increased the antitumor activity of gemcitabine by inhibiting RAS signaling by specifically targeting KRAS. This indicates that co-treatment with RT22-ep59 and gemcitabine might be considered a potential therapeutic strategy for pancreatic cancer patients harboring KRAS mutation. [ABSTRACT FROM AUTHOR]

Background: Pancreatic ductal adenocarcinoma (PDAC) is still a highly fatal malignancy among the most common cancers. More powerful treatments are expecting to bring hope for patients. Biweekly gemcitabine/nab-paclitaxel/S-1 (GAS) was proved safe and effective for patients with locally advanced pancreatic cancer in Japan. The objective of this study is to evaluate the feasibility and toxicity of GAS (repeated every 3 weeks) in the treatment of locally advanced or advanced pancreatic cancer and determine the recommended dose of S-1 in this combination.Methods: This is an open-label, single-arm, and single-center phase I trial. Patients who have been diagnosed with locally advanced or advanced PDAC pathologically without previous systemic treatments will be enrolled and be treated with GAS chemotherapy every 3 weeks (nab-paclitaxel 125 mg/m 2, ivgtt, day1, 8; gemcitabine 1000 mg/m2, day1, 8; different doses of S-1 within a dose escalation scheme) until the presence of disease progression (PD), intolerable adverse events (AEs), or requirement of patients and researchers. The primary endpoints are maximum tolerated dose (MTD) and dose-limiting toxicity (DLT). The secondary endpoints include safety, objective response rate (ORR), progression-free survival (PFS) and overall survival (OS).Discussion: This trial will adjust the administration of GAS to make it more effective for Chinese patients, while exploring the toxicity and feasibility of this adjustment.Trial Registration: ChiCTR, ( ChiCTR1900027833 ). Registered 30 November 2019. [ABSTRACT FROM AUTHOR]

Low energy electron (LEE) induced cytosine base release in a selected pyrimidine nucleotide, viz., 2'-deoxycytidine-3'-monophosphate is investigated using ab initio electronic structure methods and time dependent quantum mechanical calculations. It has been noted that the cytosine base scission is comparatively difficult process than the 3' C-O bond cleavage from the lowest π * shape resonance in energy region < 1 eV. This is mainly due to the high activation energy barrier associated with the electron transfer from the π * orbital of the base to the σ* orbital of the glycosidic N-C bond. In addition, the metastable state formed after impinging LEE (0-1 eV) has very short lifetime (10 fs) which may decay in either of the two competing auto-detachment or dissociation process simultaneously. On the other hand, the selected N-C mode may cleave to form the cytosine base anion at higher energy regions (>2 eV) via tunneling of the glycosidic bond. Resonance states generated within this energy regime will exist for a duration of ~35-55 fs. Comparison of salient features of the two dissociation events, i.e., 3' C-O single strand break and glycosidic N-C bond cleavage in 3'-dCMPH molecule are also provided. [ABSTRACT FROM AUTHOR]

Tumour-associated macrophages have been implicated in pancreatic ductal adenocarcinoma (PDAC) therapy response and Extracellular vesicles (EVs) shed by macrophages might have a role in this process. Here, we demonstrated that large EVs released by anti-inflammatory human macrophages decreased PDAC cellular sensitivity to gemcitabine. Using proteomic analysis, chitinase 3-like-1 (CHI3L1) and fibronectin (FN1) were identified as two of the most abundant proteins in the cargo of macrophages-derived EVs. Overexpression of CHI3L1 and FN1, using recombinant human proteins, induced PDAC cellular resistance to gemcitabine through ERK (extracellular-signal-regulated kinase) activation. Inhibition of CHI3L1 and FN1 by pentoxifylline and pirfenidone, respectively, partially reverted gemcitabine resistance. In PDAC patient samples, CHI3L1 and FN1 were expressed in the stroma, associated with the high presence of macrophages. The Cancer Genome Atlas analysis revealed an association between CHI3L1 and FN1 gene expression, overall survival of PDAC patients, gemcitabine response, and macrophage infiltration. Altogether, our data identifies CHI3L1 and FN1 as potential targets for pharmacological inhibition in PDAC. Further pre-clinical in vivo work is warranted to study the possibility of repurposing pentoxifylline and pirfenidone as adjuvant therapies for PDAC treatment. [ABSTRACT FROM AUTHOR]

Aberrant glycosylation in pancreatic cancer has been linked to cancer development, progression and chemoresistance. However, the role of glycogene, such as galactosyltransferase, in pancreatic cancer remains unknown. Herein, we establish beta-1.4-galactosyltransferase 1 (B4GALT1) as a clinical marker and regulator of chemoresistance. Clinically, high B4GALT1 expression correlates with poor survival, enhanced tumor size, increased lymph node metastasis, elevated cancer progression and enhanced incidence of relapse in PDAC patients. Expression of B4GALT1 is up-regulated in gemcitabine resistant patient derived organoids as well as chemoresistant cancer cell lines, while genetic perturbation of its expression in PDAC cell lines regulates cancer progression and chemoresistance. Mechanistically, we show that elevated p65 activity transcriptionally up-regulates B4GALT1 expression, which then interacts with and stabilizes cyclin dependent kinase 11 isomer CDK11p110 protein via N-linked glycosylation, in order to promote cancer progression and chemoresistance. Finally, depletion of B4GALT1 rescues the response of chemoresistant cells to gemcitabine in an orthotopic PDAC model. Overall, our data uncovers a mechanism by which p65-B4GALT1-CDK11p110 signalling axis determines cancer progression and chemoresistance, providing a new therapeutic target for an improved pancreatic cancer treatment. [ABSTRACT FROM AUTHOR]

Background: Mesothelin is a 40-kDa glycoprotein that is highly overexpressed in various types of cancers, however molecular mechanism of mesothelin has not been well-known. Amatuximab is a chimeric monoclonal IgG1/k antibody targeting mesothelin. We recently demonstrated that the combine therapy of Amatuximab and gemcitabine was effective for peritonitis of pancreatic cancer in mouse model.Methods: We discover the role and potential mechanism of mesothelin blockage by Amatuximab in human pancreatic cells both expressing high or low level of mesothelin in vitro experiment and peritonitis mouse model of pancreatic cancer.Results: Mesothelin blockage by Amatuximab lead to suppression of invasiveness and migration capacity in AsPC-1 and Capan-2 (high mesothelin expression) and reduce levels of pMET expression. The combination of Amatuximab and gemcitabine suppressed proliferation of AsPC-1 and Capan-2 more strongly than gemcitabine alone. These phenomena were not observed in Panc-1 and MIA Paca-2 (Mesothelin low expression). We previously demonstrated that Amatuximab reduced the peritoneal mass in mouse AsPC-1 peritonitis model and induced sherbet-like cancer cell aggregates, which were vanished by gemcitabine. In this study, we showed that the cancer stem cell related molecule such as ALDH1, CD44, c-MET, as well as proliferation related molecules, were suppressed in sherbet-like aggregates, but once sherbet-like aggregates attached to peritoneum, they expressed these molecules strongly without the morphological changes.Conclusions: Our work suggested that Amatuximab inhibits the adhesion of cancer cells to peritoneum and suppresses the stemness and viability of those, that lead to enhance the sensitivity for gemcitabine. [ABSTRACT FROM AUTHOR]

Background: The Phase 2 SCALOP trial compared gemcitabine with capecitabine-based consolidation chemoradiotherapy (CRT) in locally advanced pancreatic cancer (LAPC).Methods: Thirty-five systematically identified circulating biomarkers were analysed in plasma samples from 60 patients enroled in SCALOP. Each was measured in triplicate at baseline (prior to three cycles of gemcitabine-capecitabine induction chemotherapy) and, for a subset, prior to CRT. Association with overall survival (OS) was determined using univariable Cox regression and optimal thresholds delineating low to high values identified using time-dependent ROC curves. Independence from known prognostic factors was assessed using Spearman correlation and the Wilcoxon rank sum test prior to multivariable Cox regression modelling including independent biomarkers and known prognostic factors.Results: Baseline circulating levels of C-C motif chemokine ligand 5 (CCL5) were significantly associated with OS, independent of other clinicopathological characteristics. Patients with low circulating CCL5 (CCL5low) had a median OS of 18.5 (95% CI 11.76-21.32) months compared to 11.3 (95% CI 9.86-15.51) months in CCL5high; hazard ratio 1.95 (95% CI 1.04-8.65; p = 0.037).Conclusions: CCL5 is an independent prognostic biomarker in LAPC. Given the known role of CCL5 in tumour invasion, metastasis and the induction of an immunosuppressive micro-environment, targeting of CCL5-mediated pathways may offer therapeutic potential in pancreatic cancer.Clinical Trial Registration: The SCALOP trial was registered with ISRCTN, number 96169987 (registered 29 May 2008). [ABSTRACT FROM AUTHOR]

Background: The Wee1 (WEE1hu) inhibitor adavosertib and gemcitabine have shown preclinical synergy and promising activity in early phase clinical trials. We aimed to determine the efficacy of this combination in patients with ovarian cancer.Methods: In this double-blind, randomised, placebo-controlled, phase 2 trial, women with measurable recurrent platinum-resistant or platinum-refractory high-grade serous ovarian cancer were recruited from 11 academic centres in the USA and Canada. Women were eligible if they were aged 18 years or older, had an Eastern Cooperative Oncology Group performance status of 0-2, a life expectancy of more than 3 months, and normal organ and marrow function. Women with ovarian cancer of non-high-grade serous histology were eligible for enrolment in a non-randomised exploratory cohort. Eligible participants with high-grade serous ovarian cancer were randomly assigned (2:1), using block randomisation (block size of three and six) and no stratification, to receive intravenous gemcitabine (1000 mg/m2 on days 1, 8, and 15) with either oral adavosertib (175 mg) or identical placebo once daily on days 1, 2, 8, 9, 15, and 16, in 28-day cycles until disease progression or unacceptable toxicity. Patients and the team caring for each patient were masked to treatment assignment. The primary endpoint was progression-free survival. The safety and efficacy analysis population comprised all patients who received at least one dose of treatment. The trial is registered with ClinicalTrials.gov, NCT02151292, and is closed to accrual.Findings: Between Sept 22, 2014, and May 30, 2018, 124 women were enrolled, of whom 99 had high-grade serous ovarian cancer and were randomly assigned to adavosertib plus gemcitabine (65 [66%]) or placebo plus gemcitabine (34 [34%]). 25 women with non-high-grade serous ovarian cancer were enrolled in the exploratory cohort. After randomisation, five patients with high-grade serous ovarian cancer were found to be ineligible (four in the experimental group and one in the control group) and did not receive treatment. Median age for all treated patients (n=119) was 62 years (IQR 54-67). Progression-free survival was longer with adavosertib plus gemcitabine (median 4·6 months [95% CI 3·6-6·4] with adavosertib plus gemcitabine vs 3·0 months [1·8-3·8] with placebo plus gemcitabine; hazard ratio 0·55 [95% CI 0·35-0·90]; log-rank p=0·015). The most frequent grade 3 or worse adverse events were haematological (neutropenia in 38 [62%] of 61 participants in the adavosertib plus gemcitabine group vs ten [30%] of 33 in the placebo plus gemcitabine group; thrombocytopenia in 19 [31%] of 61 in the adavosertib plus gemcitabine group vs two [6%] of 33 in the placebo plus gemcitabine group). There were no treatment-related deaths; two patients (one in each group in the high-grade serous ovarian cancer cohort) died while on study medication (from sepsis in the experimental group and from disease progression in the control group).Interpretation: The observed clinical efficacy of a Wee1 inhibitor combined with gemcitabine supports ongoing assessment of DNA damage response drugs in high-grade serous ovarian cancer, a TP53-mutated tumour type with high replication stress. This therapeutic approach might be applicable to other tumour types with high replication stress; larger confirmatory studies are required.Funding: US National Cancer Institute Cancer Therapy Evaluation Program, Ontario Institute for Cancer Research, US Department of Defense, Princess Margaret Cancer Foundation, and AstraZeneca. [ABSTRACT FROM AUTHOR]

Background: Standard chemotherapy remains inadequate in metastatic pancreatic adenocarcinoma. Combining an agonistic CD40 monoclonal antibody with chemotherapy induces T-cell-dependent tumour regression in mice and improves survival. In this study, we aimed to evaluate the safety of combining APX005M (sotigalimab) with gemcitabine plus nab-paclitaxel, with and without nivolumab, in patients with pancreatic adenocarcinoma to establish the recommended phase 2 dose.Methods: This non-randomised, open-label, multicentre, four-cohort, phase 1b study was done at seven academic hospitals in the USA. Eligible patients were adults aged 18 years and older with untreated metastatic pancreatic adenocarcinoma, Eastern Cooperative Oncology Group performance status score of 0-1, and measurable disease by Response Evaluation Criteria in Solid Tumors version 1.1. All patients were treated with 1000 mg/m2 intravenous gemcitabine and 125 mg/m2 intravenous nab-paclitaxel. Patients received 0·1 mg/kg intravenous APX005M in cohorts B1 and C1 and 0·3 mg/kg in cohorts B2 and C2. In cohorts C1 and C2, patients also received 240 mg intravenous nivolumab. Primary endpoints comprised incidence of adverse events in all patients who received at least one dose of any study drug, incidence of dose-limiting toxicities (DLTs) in all patients who had a DLT or received at least two doses of gemcitabine plus nab-paclitaxel and one dose of APX005M during cycle 1, and establishing the recommended phase 2 dose of intravenous APX005M. Objective response rate in the DLT-evaluable population was a key secondary endpoint. This trial (PRINCE, PICI0002) is registered with ClinicalTrials.gov, NCT03214250 and is ongoing.Findings: Between Aug 22, 2017, and July 10, 2018, of 42 patients screened, 30 patients were enrolled and received at least one dose of any study drug; 24 were DLT-evaluable with median follow-up 17·8 months (IQR 16·0-19·4; cohort B1 22·0 months [21·4-22·7], cohort B2 18·2 months [17·0-18·9], cohort C1 17·9 months [14·3-19·7], cohort C2 15·9 months [12·7-16·1]). Two DLTs, both febrile neutropenia, were observed, occurring in one patient each for cohorts B2 (grade 3) and C1 (grade 4). The most common grade 3-4 treatment-related adverse events were lymphocyte count decreased (20 [67%]; five in B1, seven in B2, four in C1, four in C2), anaemia (11 [37%]; two in B1, four in B2, four in C1, one in C2), and neutrophil count decreased (nine [30%]; three in B1, three in B2, one in C1, two in C2). 14 (47%) of 30 patients (four each in B1, B2, C1; two in C2) had a treatment-related serious adverse event. The most common serious adverse event was pyrexia (six [20%] of 30; one in B2, three in C1, two in C2). There were two chemotherapy-related deaths due to adverse events: one sepsis in B1 and one septic shock in C1. The recommended phase 2 dose of APX005M was 0·3 mg/kg. Responses were observed in 14 (58%) of 24 DLT-evaluable patients (four each in B1, C1, C2; two in B2).Interpretation: APX005M and gemcitabine plus nab-paclitaxel, with or without nivolumab, is tolerable in metastatic pancreatic adenocarcinoma and shows clinical activity. If confirmed in later phase trials, this treatment regimen could replace chemotherapy-only standard of care in this population.Funding: Parker Institute for Cancer Immunotherapy, Cancer Research Institute, and Bristol Myers Squibb. [ABSTRACT FROM AUTHOR]

Background: Gram-negative bacteria mediated gemcitabine resistance in pre-clinical models. We determined if intratumoural lipopolysaccharide (LPS) detection by immunohistochemistry is associated with outcome in advanced pancreatic ductal adenocarcinoma (PDAC) treated with gemcitabine and non-gemcitabine containing 1st-line chemotherapy.Methods: We examined LPS on tumour tissue from 130 patients treated within the randomised AIO-PK0104 trial and a validation cohort (n = 113) and analysed the association of LPS detection to patient outcome according to treatment subgroups.Results: In 24% of samples from the AIO-PK0104 study LPS was detected; in LPS-positive patients median OS was 4.4 months, compared to 7.3 months with LPS negative tumours (HR 1.732, p = 0.010). A difference in OS was detected in 1st-line gemcitabine-treated patients (n = 71; HR 2.377, p = 0.002), but not in the non-gemcitabine treatment subgroup (n = 59; HR 1.275, p = 0.478). Within the validation cohort, the LPS positivity rate was 23%, and LPS detection was correlated with impaired OS in the gemcitabine subgroup (n = 94; HR 1.993, p = 0.008) whereas no difference in OS was observed in the non-gemcitabine subgroup (n = 19; HR 2.596, p = 0.219).Conclusions: The detection of intratumoural LPS as surrogate marker for gram-negative bacterial colonisation may serve as a negative predictor for gemcitabine efficacy in advanced PDAC.Clinical Trial Registry: The Clinical trial registry identifier is NCT00440167. [ABSTRACT FROM AUTHOR]

Background: Personalised medicine strategies may improve outcomes in pancreatic ductal adenocarcinoma (PDAC), but validation of predictive biomarkers is required. Having developed a clinical trial to assess the ATR inhibitor, AZD6738, in combination with gemcitabine (ATRi/gem), we investigated ATM loss as a predictive biomarker of response to ATRi/gem in PDAC.Methods: Through kinase inhibition, siRNA depletion and CRISPR knockout of ATM, we assessed how ATM targeting affected the sensitivity of PDAC cells to ATRi/gem. Using flow cytometry, immunofluorescence and immunoblotting, we investigated how ATRi/gem synergise in ATM-proficient and ATM-deficient cells, before assessing the impact of ATM loss on ATRi/gem sensitivity in vivo.Results: Complete loss of ATM function (through pharmacological inhibition or CRISPR knockout), but not siRNA depletion, sensitised to ATRi/gem. In ATM-deficient cells, ATRi/gem-induced replication catastrophe was augmented, while phospho-Chk2-T68 and phospho-KAP1-S824 persisted via DNA-PK activity. ATRi/gem caused growth delay in ATM-WT xenografts in NSG mice and induced regression in ATM-KO xenografts.Conclusions: ATM loss augments replication catastrophe-mediated cell death induced by ATRi/gem and may predict clinical responsiveness to this combination. ATM status should be carefully assessed in tumours from patients with PDAC, since distinction between ATM-low and ATM-null could be critical in maximising the success of clinical trials using ATM expression as a predictive biomarker. [ABSTRACT FROM AUTHOR]

Background: We investigated the impact of the age-adjusted Charlson comorbidity index (ACCI) on the pancreatic cancer survival and recurrence after curative surgery followed by adjuvant chemotherapy.Patients and Methods: This study included 155 patients who underwent curative surgery followed by adjuvant chemotherapy for pancreatic cancer between 2005 and 2014. The risk factors for the overall survival (OS) and recurrence-free survival (RFS) were identified.Results: An ACCI of 8 was regarded as the optimum critical point of classification considering the 1-, 3- and 5-year survival rates. The OS rates at 3 and 5 years after surgery were 25.7% and 19.0% in the ACCI-low group, respectively, and 7.6% and 0% in the ACCI-high group, which amounted to a statistically significant difference (P = 0.019). The RFS rates at 3 and 5 years after surgery were 17.3% and 13.8% in the ACCI-low group, respectively, and 7.1% and 0% in the ACCI-high group, which amounted to a marginally statistically significant difference (P = 0.104). A multivariate analysis showed that the ACCI was a significant independent risk factor for both the OS and RFS.Conclusions: The ACCI was a risk factor for the OS in patients who underwent curative surgery followed by adjuvant chemotherapy for pancreatic cancer. An effective plan is needed for determining the optimum surgical strategy according to the ACCI. [ABSTRACT FROM AUTHOR]

Background: The efficacy and safety of the anti-programmed death ligand 1 (PD-L1) monoclonal antibody atezolizumab, as compared with those of platinum-based chemotherapy, as first-line treatment for patients with metastatic non-small-cell lung cancer (NSCLC) with PD-L1 expression are not known.Methods: We conducted a randomized, open-label, phase 3 trial involving patients with metastatic nonsquamous or squamous NSCLC who had not previously received chemotherapy and who had PD-L1 expression on at least 1% of tumor cells or at least 1% of tumor-infiltrating immune cells as assessed by the SP142 immunohistochemical assay. Patients were assigned in a 1:1 ratio to receive atezolizumab or chemotherapy. Overall survival (primary end point) was tested hierarchically according to PD-L1 expression status among patients in the intention-to-treat population whose tumors were wild-type with respect to EGFR mutations or ALK translocations. Within the population with EGFR and ALK wild-type tumors, overall survival and progression-free survival were also prospectively assessed in subgroups defined according to findings on two PD-L1 assays as well as by blood-based tumor mutational burden.Results: Overall, 572 patients were enrolled. In the subgroup of patients with EGFR and ALK wild-type tumors who had the highest expression of PD-L1 (205 patients), the median overall survival was longer by 7.1 months in the atezolizumab group than in the chemotherapy group (20.2 months vs. 13.1 months; hazard ratio for death, 0.59; P = 0.01). Among all the patients who could be evaluated for safety, adverse events occurred in 90.2% of the patients in the atezolizumab group and in 94.7% of those in the chemotherapy group; grade 3 or 4 adverse events occurred in 30.1% and 52.5% of the patients in the respective groups. Overall and progression-free survival favored atezolizumab in the subgroups with a high blood-based tumor mutational burden.Conclusions: Atezolizumab treatment resulted in significantly longer overall survival than platinum-based chemotherapy among patients with NSCLC with high PD-L1 expression, regardless of histologic type. (Funded by F. Hoffmann-La Roche/Genentech; IMpower110 ClinicalTrials.gov number, NCT02409342.). [ABSTRACT FROM AUTHOR]

Desmoplastic small round cell tumor (DSRCT) is a type of soft-tissue sarcoma with poor prognosis. Current treatments include multidisciplinary treatment options such as surgery, chemotherapy, and radiotherapy. Apatinib is an oral, small-molecule, anti-tumor, angiogenesis-targeted drug, which acts mainly on the intracellular binding site of vascular endothelial growth factor receptor-2. In this study, we administered apatinib in combination with chemotherapy to achieve good disease control. This is a 31-year-old male who presented with upper abdominal pain, nausea, and anorexia for over a month. Imaging revealed multiple solid masses and ascites in the liver and abdominal cavity. He was diagnosed as having cholangiocarcinoma with metastasis to the liver, both lungs, bone, and multiple lymph nodes in the neck, abdominal and pelvic cavity, retroperitoneum, and palpitate angle, based on a percutaneous biopsy of the liver and an abdominal mass, and other examinations. Computed tomography revealed disease progression after two cycles of gemcitabine combined with nedaplatin chemotherapy. Next-generation sequencing detection based on the Illumina high-throughput sequencing platform suggested EWSR1 exon7- Wilms tumor 1 exon8 fusion. The pathology was verified and diagnosed as DSRCT. The chemotherapy regimen was changed to cyclophosphamide, epirubicin, vincristine, and oral apatinib for two cycles. The lesions were mostly reduced, and partial response was evaluated. This case is the first report of the efficacy of apatinib combined with systemic chemotherapy in the treatment of DSRCT, which can become an alternative treatment for this disease. [ABSTRACT FROM AUTHOR]