Key factors associated with 6-thioguanine and 6-methylmercaptopurine nucleotide concentrations in children treated by thiopurine for acute leukaemia and inflammatory bowel disease.

AIMS: Azathioprine (AZA) and 6-mercaptopurine are prescribed in acute lymphoblastic leukaemia (ALL) and inflammatory bowel diseases (IBD). Metabolism to active 6-thioguanine (6TGN) and 6-methylmercaptopurine nucleotides (6MMPN) is variable but therapeutic drug monitoring (TDM) remains debatable. This study reports on factors impacting on red blood cell (RBC) metabolites concentrations in children to facilitate TDM interpretation. METHODS: The first paediatric TDM samples received during year 2021 were analysed, whatever indication and thiopurine drug. Target concentration ranges were 200-500, <6000 pmol/8 × 108 RBC for 6TGN and 6MMPN. RESULTS: Children (n = 492) had IBD (64.8%), ALL (22.6%) or another autoimmune disease (12.6%): mean ages at TDM were 7.5 in ALL and 13.7 years in IBD (P < .0001). ALL received 6-mercaptopurine (mean dose 1.7 mg/kg/d with methotrexate), IBD received AZA (1.9 mg/kg/d with anti-inflammatory drugs and/or monoclonal antibodies). Median 6TGN and 6MMPN concentrations were 213.7 [interquartile range: 142.5; 309.6] and 1144.6 [419.4; 3574.3] pmol/8 × 108 RBC, 38.8% of patients were in the recommended therapeutic range for both compounds. Aminotransferases and blood tests were abnormal in 57/260 patients: 8.1% patients had high alanine aminotransaminase, 3.4% of patients had abnormal blood count. Factors associated with increased 6TGN were age at TDM and thiopurine methyltransferase genotype in ALL and AZA dose in IBD. The impact of associated treatment in IBD patients was also significant. CONCLUSION: TDM allowed identification of children who do not reach target levels or remain over treated. Including TDM in follow-up may help physicians to adjust dosage with the aim of reducing adverse effects and improve treatment outcome.

[17-year study on the curative effect of treatment to prevent the recurrence of hepatitis B in different risk groups after liver transplantation].

Objective: To observe the recurrence condition of hepatitis B in different risk groups after liver transplantation in an attempt to provide useful information on whether to discontinue hepatitis B immunoglobulin (HBIG) in the future at an early stage. Methods: The patient population was divided into high, low-risk, and special groups [especially primary hepatocellular carcinoma (HCC)] according to the guidelines for the prevention and treatment of hepatitis B recurrence after liver transplantation. The recurrence condition and risk factors in this population were observed for hepatitis B. Measurement data were analyzed using a t-test and a rank-sum test. Count data were compared using a χ(2) test between groups. Results: This study finally included 532 hepatitis B-related liver transplant cases. A total of 35 cases had HBV recurrence after liver transplantation, including 34 cases that were HBsAg positive, one case that was HBsAg negative, and 10 cases that were hepatitis B virus (HBV) DNA positive. The overall HBV recurrence rate was 6.6%. The recurrence rate of HBV was 9.2% and 4.8% in the high- and low-risk HBV DNA positive and negative groups before surgery (P = 0.057). Among the 293 cases diagnosed with HCC before liver transplantation, 30 had hepatitis B recurrence after surgery, with a recurrence rate of 10.2%. The independent related factors for the recurrence of hepatitis B in patients with HCC after liver transplantation were HCC recurrence (HR =181.92, 95%CI 15.99~2 069.96, P < 0.001), a high postoperative dose of mycophenolate mofetil dispersible tablets (MMF) ( HR =5.190, 95%CI 1.289~20.889, P = 0.020), and a high dosage of HBIG (HR = 1.012, 95%CI 1.001~1.023, P = 0.035). Among the 239 cases who were non-HCC before liver transplantation, five cases (recurrence rate of 2.1%) arouse postoperative hepatitis B recurrence. Lamivudine was used in all cases, combined with on-demand HBIG prophylaxis after surgery. There was no hepatitis B recurrence in non-HCC patients who treated with entecavir combined with HBIG after surgery. Conclusion: High-barrier-to-resistance nucleotide analogues combined with long-term HBIG have a good effect on preventing the recurrence of hepatitis B after liver transplantation. The discontinuation of HBIG may be considered at an early stage after administration of a high-barrier-to-resistance nucleotide analogue in low-risk patients. Domestically, the HBV infection rate is high, so further research is still required to explore the timing of HBIG discontinuation for high-risk patients, especially those with HCC.

Human immunodeficiency virus 1 5'-leader mutations in plasma viruses before and after the development of reverse transcriptase inhibitor-resistance mutations.

Human immunodeficiency virus 1 (HIV-1) reverse transcriptase (RT) initiation depends on interaction between viral 5'-leader RNA, RT and host tRNA3Lys. Therefore, we sought to identify co-evolutionary changes between the 5'-leader and RT in viruses developing RT-inhibitor resistance mutations. We sequenced 5'-leader positions 37-356 of paired plasma virus samples from 29 individuals developing the nucleoside RT inhibitor (NRTI)-resistance mutation M184V, 19 developing a non-nucleoside RT inhibitor (NNRTI)-resistance mutation and 32 untreated controls. 5'-Leader variants were defined as positions where ≥20 % of next-generation sequencing (NGS) reads differed from the HXB2 sequence. Emergent mutations were defined as nucleotides undergoing a ≥4-fold change in proportion between baseline and follow-up. Mixtures were defined as positions containing ≥2 nucleotides each present in ≥20 % of NGS reads. Among 80 baseline sequences, 87 positions (27.2 %) contained a variant; 52 contained a mixture. Position 201 was the only position more likely to develop a mutation in the M184V (9/29 vs 0/32; P=0.0006) or NNRTI-resistance (4/19 vs 0/32; P=0.02; Fisher's exact test) groups than the control group. Mixtures at positions 200 and 201 occurred in 45.0 and 28.8 %, respectively, of baseline samples. Because of the high proportion of mixtures at these positions, we analysed 5'-leader mixture frequencies in two additional datasets: five publications reporting 294 dideoxyterminator clonal GenBank sequences from 42 individuals and six National Center for Biotechnology Information (NCBI) BioProjects reporting NGS datasets from 295 individuals. These analyses demonstrated position 200 and 201 mixtures at proportions similar to those in our samples and at frequencies several times higher than at all other 5'-leader positions. Although we did not convincingly document co-evolutionary changes between RT and 5'-leader sequences, we identified a novel phenomenon, wherein positions 200 and 201 immediately downstream of the HIV-1 primer binding site exhibited an extraordinarily high likelihood of containing a nucleotide mixture. Possible explanations for the high mixture rates are that these positions are particularly error-prone or provide a viral fitness advantage.

MYC-induced cytidine metabolism regulates survival and drug resistance via cGas-STING pathway in mantle cell lymphoma.

Lymphocyte proliferation and tumourigenesis are dependent on nucleotide synthesis to support DNA, RNA and phospholipid synthesis. Here, we identified that reprogramming of nucleotide metabolism as an important factor divides mantle cell lymphoma (MCL) into two groups with different transcriptional signalling pathways and varying prognoses. We establish a nucleotide metabolism-related prognostic model that includes six genes with different regression coefficients, which significantly predicts prognosis for MCL patients (p < 0.0001). Of these six genes, de novo CTP synthesis pathway enzyme CTPS1 whose inhibitor (STP938) is already in clinical trials for relapsed/refractory lymphomas (NCT05463263) has the highest regression coefficient. An increase in CTPS1 expression predicts adverse overall survival and progression-free survival with independent prognostic significance in 105 primary MCL samples and GEO database (GSE93291). CRISPR CTPS1 knockout causes DNA damage and proliferation defects in MCL. Additionally, MYC positively regulates CTPS1 expression, and TP53-aberrant and ibrutinib-resistant MCL cells also rely on cytidine metabolism. Furthermore, besides the obvious decreased CTP pool caused by CTPS1 deficiency, CTPS1 inhibition may also induce immune-related responses via activating dsDNA-cGAS-STING pathway, which plays a crucial role in impeding tumour growth in MCL patients.

Withdrawal of Long-Term Nucleotide Analog Therapy in Chronic Hepatitis B: Outcomes From the Withdrawal Phase of the HBRN Immune Active Treatment Trial.

INTRODUCTION: Withdrawal of nucleos(t)ide analog therapy is increasingly being evaluated in chronic hepatitis B infection as a strategy to induce hepatitis B surface antigen (HBsAg) loss. The Hepatitis B Research Network Immune-Active Trial evaluated treatment with tenofovir (TDF) for 4 years ± an initial 6 months of peginterferon-α (PegIFN) (NCT01369212) after which treatment was withdrawn. METHODS: Eligible participants (hepatitis B e antigen [HBeAg]-/anti-HBe+, hepatitis B virus [HBV] DNA <10 3 IU/mL, no cirrhosis) who discontinued TDF were followed for at least 1 year with optional follow-up thereafter. Retreatment was based on predefined criteria. RESULTS: Among 201 participants who received 4 years of treatment, 97 participants (45 TDF and 52 TDF + PegIFN arm, 79 Asian) discontinued TDF. HBsAg loss occurred in 5 participants, 2 within 25 weeks and 3 within 89-119 weeks postwithdrawal (cumulative rate 4.3% by 2 years). Alanine aminotransferase (ALT) flares (>5× upper limit of normal) after TDF withdrawal occurred in 36 (37.1%) participants and occurred more frequently and earlier in those HBeAg- compared with HBeAg+ at treatment initiation. ALT flares were associated with older age and higher HBV DNA pretreatment and at the visit before the flare. ALT flares were not significantly associated with HBsAg decline or loss but were associated with immune active disease at 1 year (70.6% vs 11.9%, P < 0.0001) and 2 years (66.7% vs 25.9%, P = 0.03) postwithdrawal. Treatment reinitiation was required in 13 (13.4%) participants, and 13 others remained in a sustained inactive carrier state by the end of the study follow-up. No criteria reliably predicted safe treatment withdrawal. DISCUSSION: Results from this trial do not support TDF withdrawal as a therapeutic strategy. HBsAg loss was infrequent within 2 years of stopping long-term TDF. If withdrawal is considered, HBV DNA should be carefully monitored with reinitiation of therapy if levels rise above 4 log 10 IU/mL to reduce the risk of ALT flares, as they were not associated with subsequent HBsAg decline or loss.

A randomized phase 1b trial of the active site polymerase inhibitor nucleotide ATI-2173 in patients with chronic hepatitis B virus infection.

ATI-2173 is an active site polymerase inhibitor nucleotide in development as part of a potentially curative regimen for chronic hepatitis B virus (HBV) infection. This study evaluated the safety, tolerability, pharmacokinetics (PK) and antiviral activity of ATI-2173. This was a phase 1b, randomized, double-blind, placebo-controlled trial in treatment-naive adults with chronic HBV infection conducted in the Republic of Moldova and Ukraine (ClinicalTrials.gov: NCT04248426). Patients positive for hepatitis B surface antigen were randomized 6:2 to receive once-daily oral doses of ATI-2173 10, 25, or 50 mg (n = 6 per dose) or placebo (n = 7) for 28 days, with off-treatment monitoring for 24 weeks. Endpoints included PK parameters of ATI-2173 and its metabolite clevudine, maximum reduction from baseline in HBV DNA, and safety and tolerability. Treatment-emergent adverse events occurred in eight patients (47%) receiving ATI-2173 and five (71%) receiving placebo; headache was the most common (n = 4). ATI-2173 PK was generally dose proportional. Systemic clevudine exposure with ATI-2173 dosing was substantially reduced compared with historical values observed with clevudine administration. On Day 28, mean changes from baseline in HBV DNA were -2.72 to -2.78 log10  IU/ml with ATI-2173 and +0.17 log10  IU/ml with placebo. Off-treatment sustained viral suppression and decreases in covalently closed circular DNA biomarkers were observed in most patients; one maintained undetectable HBV DNA at 24 weeks off treatment. In this 28-day monotherapy study, ATI-2173 demonstrated safety and antiviral activity, with sustained off-treatment effects and substantially reduced systemic clevudine exposure. These results support evaluation of ATI-2173 with tenofovir disoproxil fumarate in phase 2 studies.

PTEN-induced kinase 1 gene single-nucleotide variants as biomarkers in adjuvant chemotherapy for colorectal cancer: a retrospective study.

BACKGROUND: Fluoropyrimidine-based postoperative adjuvant chemotherapy is globally recommended for high-risk stage II and stage III colon cancer. However, adjuvant chemotherapy is often associated with severe adverse events and is not highly effective in preventing recurrence. Therefore, discovery of novel molecular biomarkers of postoperative adjuvant chemotherapy to identify patients at increased risk of recurrent colorectal cancer is warranted. Autophagy (including mitophagy) is activated under chemotherapy-induced stress and contributes to chemotherapy resistance. Expression of autophagy-related genes and their single-nucleotide polymorphisms are reported to be effective predictors of chemotherapy response in some cancers. Our goal was to evaluate the relationship between single-nucleotide variants of autophagy-related genes and recurrence rates in order to identify novel biomarkers that predict the effect of adjuvant chemotherapy in colorectal cancer. METHODS: We analyzed surgical or biopsy specimens from 84 patients who underwent radical surgery followed by fluoropyrimidine-based adjuvant chemotherapy at Saitama Medical University International Medical Center between January and December 2016. Using targeted enrichment sequencing, we identified single-nucleotide variants and insertions/deletions in 50 genes, including autophagy-related genes, and examined their association with colorectal cancer recurrence rates. RESULTS: We detected 560 single-nucleotide variants and insertions/deletions in the target region. The results of Fisher's exact test indicated that the recurrence rate of colorectal cancer after adjuvant chemotherapy was significantly lower in patients with the single-nucleotide variants (c.1018G > A [p < 0.005] or c.1562A > C [p < 0.01]) of the mitophagy-related gene PTEN-induced kinase 1. CONCLUSIONS: The two single-nucleotide variants of PINK1 gene may be biomarkers of non-recurrence in colorectal cancer patients who received postoperative adjuvant chemotherapy.

Exploratory metabolomic analysis based on UHPLC-Q-TOF-MS/MS to study hypoxia-reoxygenation energy metabolic alterations in HK-2 cells.

PURPOSE: Renal ischemia-reperfusion injury(IRI)is a major cause of acute kidney injury(AKI), the injury and repair of renal tubular epithelial cells play an important role in the pathological process of IR-AKI. Metabolomics was used to detect cell metabolism alterations and metabolic reprogramming in the initial injury, peak injury, and recovery stage of human renal proximal tubular cells (HK-2 cells) to provide insights into clinical prevention and treatment of IRI-induced AKI. METHODS: An in vitro ischemia-reperfusion (H/R) injury and the recovery model of HK-2 cells were established at different times of hypoxia/reoxygenation. Comprehensive detection of metabolic alterations in HK-2 cells after H/R induction by nontarget metabolomics. Interconversion of glycolysis and fatty acid oxidation (FAO) in HK-2 cells after H/R induction was examined by western blotting and qRT-PCR. RESULTS: Multivariate data analysis found significant differences among the groups, with significant changes in metabolites such as glutamate, malate, aspartate, and L-palmitoylcarnitine. Hypoxia-reoxygenated HK-2 cells are accompanied by altered metabolisms such as disturbance of amino acid and nucleotide metabolism, dysregulation of lipid metabolism, increased glycolysis, and metabolic reprogramming, which manifests as a shift in energy metabolism from FAO to glycolysis. CONCLUSION: The development of IRI-induced AKI in HK-2 cells is accompanied by the disturbance of amino acid, nucleotide, and tricarboxylic acid cycle metabolism and specifically metabolic reprogramming of FAO to glycolytic conversion. The timely recovery of energy metabolism in HK-2 cells is of great significance for treating and prognosis IRI-induced AKI.

[Impact of nucleosides analogues and nucleotide analogues on the outcomes related to chronic hepatitis B based on non-antiviral effects].

Nucleoside analogues and nucleotide analogues can not only achieve long-term viral suppression in the treatment of most CHB patients but also have a positive impact on other CHB therapeutic goals and an improved prognosis. A certain difference can be observed in the impact of nucleotide analogues such as TDF and TAF and nucleoside analogues such as ETV on the clinical outcomes of CHB. Studies on the mechanism of action indicate that apart from inhibiting the direct antiviral effects of HBV reverse transcriptase, these two categories of drugs exhibit distinct impacts on immune-related signaling pathways, gene expression, genome stability, and other non-antiviral mechanisms. This article reviews the evidence on the potential non-antiviral mechanism of action of nucleoside analogues and nucleotide analogues and proposes a preliminary explanation for the observation trend of nucleotide analogues having a comparative advantage in clinical outcomes in CHB patients based on the latest research advancement.

Long noncoding RNA OVAAL enhances nucleotide synthesis through pyruvate carboxylase to promote 5-fluorouracil resistance in gastric cancer.

5-Fluorouracil (5-FU) is widely used in gastric cancer treatment, yet 5-FU resistance remains an important clinical challenge. We established a model based on five long noncoding RNAs (lncRNA) to effectively assess the prognosis of gastric cancer patients; among them, lncRNA OVAAL was markedly upregulated in gastric cancer and associated with poor prognosis and 5-FU resistance. In vitro and in vivo assays confirmed that OVAAL promoted proliferation and 5-FU resistance of gastric cancer cells. Mechanistically, OVAAL bound with pyruvate carboxylase (PC) and stabilized PC from HSC70/CHIP-mediated ubiquitination and degradation. OVAAL knockdown reduced intracellular levels of oxaloacetate and aspartate, and the subsequent pyrimidine synthesis, which could be rescued by PC overexpression. Moreover, OVAAL knockdown increased sensitivity to 5-FU treatment, which could be reversed by PC overexpression or repletion of oxaloacetate, aspartate, or uridine. OVAAL overexpression enhanced pyrimidine synthesis to promote proliferation and 5-FU resistance of gastric cancer cells, which could be abolished by PC knockdown. Thus, OVAAL promoted gastric cancer cell proliferation and induced 5-FU resistance by enhancing pyrimidine biosynthesis to antagonize 5-FU induced thymidylate synthase dysfunction. Targeting OVAAL-mediated nucleotide metabolic reprograming would be a promising strategy to overcome chemoresistance in gastric cancer.

Targeting miR-21 in spinal cord injuries: a game-changer?

Spinal cord injury (SCI) is a devastating neurological state causing physical disability, psychological stress and financial burden. SCI global rate is estimated between 250,000 and 500,000 individuals every year, of which 60% of victims are young, healthy males between 15 and 35 years. A variety of pathological conditions such as neuroinflammation, mitochondrial dysfunction, apoptosis, glial scar formation, blood-spinal cord barrier disruption, and angiogenesis disruption occur after SCI leading to a limitation in recovery. MicroRNAs (miRs) are endogenous and non-coding RNAs consisting of 22 nucleotides that regulate 60% of all human genes and involve several normal physiological processes and pathological conditions. miR-21 is among the most highly expressed miRs and its expression has been shown to increase one day after SCI and this elevation is sustained up to 28 days after injury. Overexpression of miR-21 exerts many protective effects against SCI by inhibiting neuroinflammation, improving blood-spinal cord barrier function, regulating angiogenesis, and controlling glial scar formation. It also exhibits anti-apoptotic effects in SCI by down-regulating the expression of PTEN, Spry2, and PDCD4. This review provides a novel therapeutic perspective for miR-21 in SCI.

Effects of gentamicin inducing readthrough premature stop Codons: A study of alpha-L-iduronidase nonsense variants in COS-7 Cells.

Mucopolysaccharidosis type I Hurler syndrome (MPS IH) is a severe lysosomal storage disorder caused by alpha-l-iduronidase (IDUA) deficiency. Premature truncation mutations (PTC) are the most common (50%-70%) type of IDUA mutations and correlate with MPS IH. Nonsense suppression therapy is a therapeutic approach that aims to induce stop codon readthrough. The different ability of gentamicin to bind mutant mRNA in readthrough is determined by nucleotide sequence (PTC context: UGA > UAG > UAA) and inserted amino acid including the nucleotide position +4 of the PTC, as well as the mRNA secondary structure. We used COS-7 cells to investigate the functional characteristics of p.Q500X and p.R619X, IDUA variants and the effects of gentamicin in inducing stop codon readthrough of seven IDUA variants including p.Q500X, p.R619X, p.Q70X, p.E299X, p.W312X, p.Q380X, and p.W402X. Moreover, we performed prediction of RNA secondary structure using the online tool RNAfold. We found that cells treated with gentamicin showed significantly enhanced full-length IDUA expression and restored IDUA activity, in a dose-dependent manner, only in cells expressing cDNA with W312X, Q380X, W402X, and R619X. Among the readthrough-responsive variants, we observed UGA PTC in W312X, W402X and R619X; and UAG PTC with C at nucleotide +4 in Q380X. Changes of RNA secondary structure were noted only in mutants with readthrough-responsive variants including W312X, Q380X, W402X, and R619X. Additional preclinical studies of selected PTCs with potential readthrough, using drugs with less oto-nephrotoxicity, in patient's skin fibroblasts and animal model are necessary for the premise of personalized medicine.

Feasibility and outcome of reproducible clinical interpretation of high-dimensional molecular data: a comparison of two molecular tumor boards.

BACKGROUND: Structured and harmonized implementation of molecular tumor boards (MTB) for the clinical interpretation of molecular data presents a current challenge for precision oncology. Heterogeneity in the interpretation of molecular data was shown for patients even with a limited number of molecular alterations. Integration of high-dimensional molecular data, including RNA- (RNA-Seq) and whole-exome sequencing (WES), is expected to further complicate clinical application. To analyze challenges for MTB harmonization based on complex molecular datasets, we retrospectively compared clinical interpretation of WES and RNA-Seq data by two independent molecular tumor boards. METHODS: High-dimensional molecular cancer profiling including WES and RNA-Seq was performed for patients with advanced solid tumors, no available standard therapy, ECOG performance status of 0-1, and available fresh-frozen tissue within the DKTK-MASTER Program from 2016 to 2018. Identical molecular profiling data of 40 patients were independently discussed by two molecular tumor boards (MTB) after prior annotation by specialized physicians, following independent, but similar workflows. Identified biomarkers and resulting treatment options were compared between the MTBs and patients were followed up clinically. RESULTS: A median of 309 molecular aberrations from WES and RNA-Seq (n = 38) and 82 molecular aberrations from WES only (n = 3) were considered for clinical interpretation for 40 patients (one patient sequenced twice). A median of 3 and 2 targeted treatment options were identified per patient, respectively. Most treatment options were identified for receptor tyrosine kinase, PARP, and mTOR inhibitors, as well as immunotherapy. The mean overlap coefficient between both MTB was 66%. Highest agreement rates were observed with the interpretation of single nucleotide variants, clinical evidence levels 1 and 2, and monotherapy whereas the interpretation of gene expression changes, preclinical evidence levels 3 and 4, and combination therapy yielded lower agreement rates. Patients receiving treatment following concordant MTB recommendations had significantly longer overall survival than patients receiving treatment following discrepant recommendations or physician's choice. CONCLUSIONS: Reproducible clinical interpretation of high-dimensional molecular data is feasible and agreement rates are encouraging, when compared to previous reports. The interpretation of molecular aberrations beyond single nucleotide variants and preclinically validated biomarkers as well as combination therapies were identified as additional difficulties for ongoing harmonization efforts.

Association of genetic polymorphisms of CYP3A4 and CYP2D6 with gefitinib-induced toxicities.

Dermatological, gastrointestinal and hepatic toxicities are the most common adverse events associated with gefitinib use. Gefitinib is metabolized by cytochrome P450. Inconsistent associations of single nucleotide genetic polymorphisms of CYP450 and gefitinib-induced adverse effects were reported. We aim to investigate the association between CYP450 genetic polymorphism and the development of gefitinib-associated adverse events. A retrospective cohort study of Chinese patients with metastatic nonsmall cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations who received first-line gefitinib treatment was conducted. Single nucleotide polymorphisms (SNPs) of CYP2D6, CYP3A4 and CYP3A5 were assayed using a multiplex SNP microarray. Risks of development of gefitinib-induced toxicities associated with different SNPs were determined. Among the 152 patients treated with gefitinib, 52 (34.2%) had gefitinib-induced hepatotoxicity, 113 (74.3%) had cutaneous reactions and 53 (34.9%) had gastrointestinal adverse effects. CYP2D6*41 CT, CYP2D6*10 AA and CYP3A4*1/*1G TT genotypes were significantly associated with hepatic, cutaneous and gastrointestinal adverse effects [odds ratio (OR) 3.773; (95% confidence interval {CI},1.046-13.610; P = 0.043), 3.368 (95% CI, 1.000-11.345; P = 0.050) and 20.000 (95% CI, 2.381-167.965; P = 0.006), respectively]. CYP2D6*41 CT, CYP2D6*10 AA and CYP3A4*1/*1G TT genotypes may be associated with increased risks of gefitinib-induced toxicities in the liver, skin and gastrointestinal tract.

Therapeutic drug monitoring of thiopurines: Effect of reduced 6-thioguanine nucleotide target levels in inflammatory bowel disease patients.

AIMS: The effect of the Dutch nationwide adjustment of reducing 6-thioguanine nucleotide (6-TGN) target values (from 600-1200 to 320-630 pmol/8 × 108 red blood cells [RBC]) on toxicity and clinical outcome of thiopurine treatment in patients with inflammatory bowel disease has not yet been established. Therefore, the authors determined the incidence of toxicity-induced discontinuations and efficacy at both target concentrations. METHODS: This retrospective study was performed in inflammatory bowel disease patients treated with azathioprine or mercaptopurine. Two groups were defined: the former target (FT) group with target concentrations of 600-1200 pmol/8 × 108 RBC and the adjusted target (AT) group with target concentrations of 320-630 pmol/8 × 108 RBC. Patients were followed for maximum 52 weeks or until discontinuation of thiopurine therapy. Data were collected from the local hospital electronic health software of Rijnstate Hospital. RESULTS: In total, 151 patients were included, 76 in the FT group and 75 in the AT group. At week 52, 100 out of 151 patients (66%) of the total population discontinued thiopurine therapy. Forty-eight of the discontinuations were due toxicity (48%). The incidence of toxicity induced discontinuations was 35% in the AT group vs. 47% in the FT group (P = .25). No loss of efficacy was seen in the AT group. CONCLUSION: After reduction of the target range, there was a trend towards fewer toxicity-induced discontinuations, albeit not statistically significant. In addition, this study did not find any indication that the reduction of the target range diminished efficacy.

Long non-coding RNA SNHG5 mediates periodontal inflammation through the NF-κB signalling pathway.

AIM: We investigated the role of long non-coding RNAs and small nucleolar RNA host gene 5 (SNHG5) in the pathogenesis of periodontitis. MATERIALS AND METHODS: A ligature-induced periodontitis mouse model was established, and gingival tissues were collected from patients with periodontitis and healthy controls. Inflammatory cytokines were detected using quantitative reverse transcription-polymerase chain reaction and western blotting analyses. Direct interactions between SNHG5 and p65 were detected by RNA pull-down and RNA immunoprecipitation assays. Micro-computed tomography, haematoxylin and eosin staining, and immunohistochemical staining were used to measure periodontal bone loss. RESULTS: SNHG5 expression was down-regulated in human and mouse periodontal tissues compared to that in the healthy controls. In vitro experiments demonstrated that SNHG5 significantly ameliorated tumour necrosis factor α-induced inflammation. Mechanistically, SNHG5 directly binds to the nuclear factor-kappa B (NF-κB) p65 subunit and inhibits its translocation, thereby suppressing the NF-κB signalling pathway activation and reducing the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing three inflammasome expression. Locally injecting si-SNHG5 aggravated the periodontal destruction. CONCLUSION: This study revealed that SNHG5 mediates periodontal inflammation through the NF-κB signalling pathway, providing a potential therapeutic target for periodontitis treatment.

Therapeutic Approaches Targeting miRNA in Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a potentially fatal systemic autoimmune disease, and its etiology involves both genetic and environmental factors such as sex hormone imbalance, genetic predisposition, epigenetic regulation, and immunological factors. Dysregulation of microRNA (miRNA) is suggested to be one of the epigenetic factors in SLE. miRNA is a 22-nucleotide single-stranded noncoding RNA that contributes to post-transcriptional modulation of gene expression. miRNA targeting therapy has been suggested to be useful for the treatment of cancers and other diseases. Gene knockout and miRNA targeting therapy have been demonstrated to improve SLE disease activity in mice. However, these approaches have not yet reached the level of clinical application. miRNA targeting therapy is limited by the fact that each miRNA has multiple targets. In addition, the expression of certain miRNAs may differ among cell tissues within a single SLE patient. This limitation can be overcome by targeted delivery and chemical modifications. In the future, further research into miRNA chemical modifications and delivery systems will help us develop novel therapeutic agents for SLE.

Evaluation of AT-752, a Double Prodrug of a Guanosine Nucleotide Analog with In Vitro and In Vivo Activity against Dengue and Other Flaviviruses.

Every year, millions of people worldwide are infected with dengue virus (DENV), with a significant number developing severe life-threatening disease. There are currently no broadly indicated vaccines or therapeutics available for treatment of DENV infection. Here, we show that AT-281, the free base of AT-752, an orally available double prodrug of a guanosine nucleotide analog, was a potent inhibitor of DENV serotypes 2 and 3 in vitro, requiring concentrations of 0.48 and 0.77 µM, respectively, to inhibit viral replication by 50% (EC50) in Huh-7 cells. AT-281 was also a potent inhibitor of all other flaviviruses tested, with EC50 values ranging from 0.19 to 1.41 µM. Little to no cytotoxicity was observed for AT-281 at concentrations up to 170 µM. After oral administration of AT-752, substantial levels of the active triphosphate metabolite AT-9010 were formed in vivo in peripheral blood mononuclear cells of mice, rats, and monkeys. Furthermore, AT-9010 competed with GTP in RNA template-primer elongation assays with DENV2 RNA polymerase, which is essential for viral replication, with incorporation of AT-9010 resulting in termination of RNA synthesis. In AG129 mice infected with DENV D2Y98P, treatment with AT-752 significantly reduced viremia and morbidity and increased survival. The demonstrated in vitro and in vivo activity of AT-752 suggests that it is a promising compound for the treatment of dengue virus infection and is currently under evaluation in clinical studies.

Dynamic evaluation of hepatocellular carcinoma prediction models in patients with chronic hepatitis B receiving nucleotide/nucleoside analogue treatment.

Carcinogenesis risk scores for chronic hepatitis B have been proposed, but it remains unclear whether these scores during nucleoside/nucleotide analogue (NA) therapy are useful for risk assessment. In this study, we examined changes of these scores and the predictability during NA treatment. 432 patients with no history of hepatocellular carcinoma (HCC) treated with NA were enrolled. PAGE-B, modified PAGE-B (mPAGE-B), and REACH-B scores were calculated at NA administration, 1 and 2 years after administration. The median follow-up duration was 5.1 years, during which 37 patients (8.6%) developed HCC. Cumulative incidence HCC development in patients with high risk of PAGE at NA administration, and 1 and 2 years after NA administration was significantly higher than those with intermediate and low-risk groups (p < .05 for all time points), whereas HCC incidence in patients with high risk of mPAGE-B and REACH-B at 2 years after NA administration were equivalent to those with intermediate and low-risk groups (p = .2 for mPAGE-B, and p = .1 for REACH-B). The area under the receiver operating characteristic (AUROC) for HCC development of PAGE-B at NA administration, and 1 and 2 years after administration were 0.773, 0.803 and 0.737, respectively. The AUROCs of PAGE-B at each point were continuously higher than those of REACH-B (0.646, 0.725, and 0.653, respectively) and mPAGE-B (0.754, 0.734, and 0.678, respectively).PAGE-B score has a high diagnostic accuracy for HCC development at any time point during NA treatment, indicating its potential use as a real-time monitor of HCC development.

Changes of cytokine levels and T cell surface molecules in patients with chronic hepatitis B and the association with functional cure.

This study aimed to examine changes in levels of cytokine and T cell surface molecules in chronic hepatitis B (CHB) patients receiving sequential interferon therapy following 1-year nucleos(t)ide analogs (NAs) treatment. Cytokine levels were measured in 30 patients, and T cell surface molecule expression was measured in 48 patients receiving sequential interferon therapy and 24 patients only receiving NA mono-therapy. An HBsAg titer of <0.05 IU/ml was defined as a "functional cure." In the cured group (HBsAg < 0.05 IU/ml), a decreasing probability was observed in IFN-γ (after Week 0), and IL-22 and IP-10 (after Week 12). In the non-cured group (HBsAg ≥ 0.05 IU/ml), a probability of slightly decreasing was observed for IFN-γ (after Week 12), and a probability of increasing IP-10 concentration (after Week 0) was observed. Generalized estimating equation (GEE) analyses showed significant differences in the levels of IL-10, IL-23, CCL-3, IL-1ß, IL-2, and IL-12P70 between the two groups. In GEE analysis, there were significant differences in expressions of CD45RO+ between the cured group and the non-cured group. The frequencies of T cells expressing Tim-3, CD62L, and CD152 were significantly lower in the sequential interferon therapy group than in the NA mono-therapy group. Changes in cytokine levels (IFN-γ, IP-10, IL-10, IL-23, CCL-3, IL-1ß, IL-2, and IL-12P70) and T cell surface molecules (CD45RO+ ) may predict HBsAg seroconversion in CHB patients receiving sequential interferon therapy. The period from Weeks 12 to 24 during sequential interferon therapy may be a critical time of immune status change.