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Background: BI 2536, a novel Polo-like kinase 1 inhibitor, was assessed in patients with unresectable advanced exocrine adenocarcinoma of the pancreas. Methods: The study employed a two-stage design. Randomised first-line patients received BI 2536 200 mg on day 1 ( n =43) or 60 mg on days 1–3 ( n =43) every 21 days. Recruitment of second-line patients was planned for a second stage dependent on an interim analysis demonstrating ⩾2 responses in the first 18 evaluable patients following 12 weeks of treatment and/or tumour control ⩾12 weeks in 5 patients per schedule. Primary end point was objective response rate (ORR). Results: By independent review, ORR was 2.3% (all partial) and 24.4% had stable disease as confirmed best response. The second stage was not initiated. Median overall and progression-free survivals were 149 (95% confidence interval (CI), 91–307) and 46 days (95% CI, 44–56). Most common drug-related adverse events were neutropenia (37.2%), leukopenia (29.1%), fatigue (29.1%) and nausea (22.1%); most common grade 3/4-related events were neutropenia (36.0%), leukopenia (27.9%) and thrombocytopenia (8.1%). Conclusion: Given the low ORR and poor survival, further development of BI 2536 monotherapy is not warranted in this population.

Background Volasertib, a potent and selective polo-like kinase inhibitor, has shown to increase response rates and improve survival with a clinically manageable safety profile, administered alone and in combination with cytarabine in patients with acute myeloid leukaemia. Objectives The objectives of this analysis were to describe the pharmacokinetics of volasertib and cytarabine, administered as single agents or in combination. Methods Three thousand, six hundred and six plasma volasertib concentrations from 501 patients receiving either volasertib alone, or in combination with cytarabine, and 826 plasma cytarabine concentrations from 650 patients receiving cytarabine as multiple subcutaneous injections per cycle either alone, or in combination with volasertib, were analysed using NONMEM Version 7.3. Covariates evaluated included demographic and disease-related parameters. Results The pharmacokinetics of volasertib were found to be dose independent from 150 to 550 mg. Body surface area and ethnicity showed significant effects in all the patients. This is reflected as an increase in drug exposure for Japanese patients, although this finding has to be interpreted with caution because only 7% of patients were part of that population group. Volasertib showed low-to-mild inter-individual variability in total clearance. For the case of cytarabine, its pharmacokinetics was affected by body surface area. Finally, volasertib and cytarabine did not influence the pharmacokinetic characteristics of each other. Conclusions The pharmacokinetics of volasertib in patients with acute myeloid leukaemia alone or in combination with cytarabine is predictable and associated with low-to-mild patient variability with the exception of the high variability associated with the volume of distribution of the central compartment, having no effect on the area under the plasma concentration–time curve.

Background: Polo-like kinase 1 (Plk1) has an important role in mitosis. Volasertib (BI 6727), a potent and selective cell cycle kinase inhibitor, induces mitotic arrest and apoptosis by targeting Plk; this phase I study sought to determine its maximum tolerated dose (MTD) in Asian patients with advanced solid tumours. Methods: Patients were enrolled simultaneously into two 3-week schedules of volasertib: a 2-h infusion on day 1 (schedule A) or days 1 and 8 (schedule B). Dose escalation followed a 3+3 design. The MTD was determined based on dose-limiting toxicities (DLT) in the first treatment course. Results: Among 59 treated patients, the most common first course DLTs were reversible thrombocytopenia, neutropenia and febrile neutropenia; MTDs were 300 mg for schedule A and 150 mg for schedule B. Volasertib exhibited multi-exponential pharmacokinetics (PK), a long terminal half-life of ∼135 h, a large volume of distribution (>3000 l), and a moderate clearance. Partial responses were observed in two pre-treated patients (ureteral cancer; melanoma). Volasertib was generally well tolerated, with an adverse event profile consistent with its antimitotic mode of action and a favourable PK profile. Conclusions: These data support further development of volasertib and a harmonised dosing for Asian and Caucasian patients.

Background Alterations in specific pteridine metabolites, particularly neopterin, biopterin, and tetrahydrobiopterin have been reported in mild cognitive impairment, Alzheimer’s disease, and other types of dementia. However, the available evidence regarding such alterations has not been comprehensively and critically appraised. Methods We systematically reviewed studies reporting the concentrations of biopterin, tetrahydrobiopterin, and neopterin in different biological fluids in patients with mild cognitive impairment, Alzheimer’s disease or other types of dementia, and healthy controls. Electronic databases were searched from inception to 29 February 2024. Results Overall, there were no significant differences in plasma/serum concentrations of neopterin between patients with mild cognitive impairment, Alzheimer’s disease, or other types of dementia, when grouped together, and healthy controls after adjusting for publication bias (11 studies, standard mean difference, SMD = 0.20, 95% CI -0.02 to 0.41, p  = 0.076). In meta-regression and subgroup analysis, the effect size was significantly associated with age, number of participants, study continent, presence of mild cognitive impairment, presence of Alzheimer’s disease, analytical method, and assessment of serum vs. plasma. One study reported higher urine neopterin in patients with Alzheimer’s disease vs. controls whereas another study reported non-significant between-group differences in cerebrospinal neopterin. The cerebrospinal fluid concentrations of biopterin were significantly lower in patients with Alzheimer’s disease vs. controls (two studies, SMD = -0.75, 95% CI -1.23 to -0.27, p  = 0.002; I 2  = 0.0%, p  = 0.46). One study showed non-significant between-group differences in plasma biopterin whereas another study showed higher concentrations of urine biopterin in patients with Alzheimer’s disease. Our search did not identify studies investigating tetrahydrobiopterin. Conclusion Our study showed no significant differences in circulating neopterin between patients with mild cognitive impairment, Alzheimer’s disease, or other types of dementia, when grouped together, and healthy controls. The significant associations observed between the effect size and mild cognitive impairment and Alzheimer’s disease in subgroup analysis warrant further investigation. (PROSPERO registration number: CRD42024523478).

The MUSASHI (MSI) family of RNA binding proteins (MSI1 and MSI2) contribute to a wide spectrum of cancers including acute myeloid leukemia. We find that the small molecule Ro 08–2750 (Ro) binds directly and selectively to MSI2 and competes for its RNA binding in biochemical assays. Ro treatment in mouse and human myeloid leukemia cells results in an increase in differentiation and apoptosis, inhibition of known MSI-targets, and a shared global gene expression signature similar to shRNA depletion of MSI2. Ro demonstrates in vivo inhibition of c-MYC and reduces disease burden in a murine AML leukemia model. Thus, we identify a small molecule that targets MSI’s oncogenic activity. Our study provides a framework for targeting RNA binding proteins in cancer. The RNA binding protein MUSASHI-2 (MSI2) is a potential therapeutic target for acute myeloid leukemia. Here the authors identify a small molecule inhibitor of MSI2 and characterize its effects in a murine leukemia model.

Naturalists have been fascinated for centuries by animal colors and color patterns. While widely studied at the adult stage, we know little about color patterns in the embryo. Here, we study a trait consisting of coloration that is specific to the embryo and absent from postembryonic stages in water striders (Gerromorpha). By combining developmental genetics with chemical and phylogenetic analyses across a broad sample of species, we uncovered the mechanisms underlying the emergence and diversification of embryonic colors in this group of insects. We show that the pteridine biosynthesis pathway, which ancestrally produces red pigment in the eyes, has been recruited during embryogenesis in various extraocular tissues including antennae and legs. In addition, we discovered that this cooption is common to all water striders and initially resulted in the production of yellow extraocular color. Subsequently, 6 lineages evolved bright red color and 2 lineages lost the color independently. Despite the high diversity in colors and color patterns, we show that the underlying biosynthesis pathway remained stable throughout the 200 million years of Gerromorpha evolutionary time. Finally, we identified erythropterin and xanthopterin as the pigments responsible for these colors in the embryo of various species. These findings demonstrate how traits can emerge through the activation of a biosynthesis pathway in new developmental contexts.

Recent studies have demonstrated that the fish liver protein fraction extract obtained by gel filtration exhibits nitric oxide synthase (NOS)-independent NO synthase from nitrates and nitrites. This activity was attributed to the molybdenum enzymes (Mo-enzymes) group which was already demonstrated in mammals. However, the evidence that NOS-independent NO synthase activity can be classified as a fish Mo-enzyme has been poorly demonstrated. In mammals, Mo-enzymes NOS-independent NO synthase activity occurs at the molybdenum center. We studied the ability of molybdenum cofactor (Mo-co) isolated from the protein fraction of fish liver extract to restore the NADPH-nitrate reductase (NADPH-NR) activity from Neurospora crassa nit-1 . Our results demonstrated that Mo-co from the extract from fish liver was able to recover NADPH-NR activity in the extract of N. crassa nit-1 , thereby possessing the ability to reduce nitrogen compounds. However, the oxidation of Mo-co from fish liver destabilizes molybdenum, leading to its inactivation. However, the results obtained under anaerobic conditions with dithionite indicate that Mo remains bound to Mo-co under highly reducing conditions. This may also indicate that the availability of Mo is not the sole factor affecting the activity of Mo-enzymes, also oxygen content after the synthesis of mature Mo-co may play a role in cofactor inactivation.

Escherichia coli is an important model organism in microbiology and a prominent member of the human microbiota 1 . Environmental isolates readily colonize the gastrointestinal tract of humans and other animals, and they can serve diverse probiotic, commensal and pathogenic roles in the host 2 – 4 . Although certain strains have been associated with the severity of inflammatory bowel disease (IBD) 2 , 5 , the diverse immunomodulatory phenotypes remain largely unknown at the molecular level. Here, we decode a previously unknown E. coli metabolic pathway that produces a family of hybrid pterin–phenylpyruvate conjugates, which we named the colipterins. The metabolites are upregulated by subinhibitory levels of the antifolate sulfamethoxazole, which is used to treat infections including in patients with IBD 6 , 7 . The genes folX/M and aspC/tyrB involved in monapterin biosynthesis 8 – 10 and aromatic amino acid transamination, 11 respectively, were required to initiate the colipterin pathway. We show that the colipterins are antioxidants, harbour diverse immunological activities in primary human tissues, activate anti-inflammatory interleukin-10 and improve colitis symptoms in a colitis mouse model. Our study defines an antifolate stress response in E. coli and links its associated metabolites to a major immunological marker of IBD. Subinhibitory levels of sulfamethoxazole, an antibiotic used to treat Escherichia coli infections, trigger a previously undescribed metabolic pathway in E. coli that comprises a family of hybrid pterin–phenylpyruvate conjugates called colipterins. These metabolites are antioxidants, have immunomodulatory properties and improve colitis in a murine model.

Tumor microenvironment is closely related to the occurrence and development of liver cancer. Tumor-associated macrophages (TAMs) are an important part of tumor microenvironment promoting tumor deterioration and metastasis by inhibiting immune cells. Previous studies showed that PI3Kγ inhibitor could reverse the phenotype of TAMs, relieve immunosuppression and sensitize chemotherapy drugs, suggesting that the combination of PI3Kγ inhibitor and chemotherapeutics is likely to bring new breakthroughs in the treatment of liver cancer. Based on it, this paper builds HES-TG100-115-CDM-PEG micelles with tumor microenvironment responsiveness that simultaneously loaded sorafenib and TG100-115 to synergistically treat liver cancer. Pharmacokinetic study showed that the prepared micelles had longer half-life than that of the free drug solutions, which was favorable for high propensity of extravasation through tumor vascular fenestrations. Under low pH and high α-amylasereductive conditions, micelles could depolymerize quickly due to the sensitivity of bonds and enhance significantly cytotoxic activity against Hep-3B liver cancer cell. Additionally, micelles demonstrated higher levels of antitumor efficiency and better tolerance against nude mouse with Hep-3B cell than the free drug solutions. These findings reveal that HES-TG100-115-CDM-PEG micelles are a promising drug delivery system in clinical comprehensive therapy of liver cancer.

Pterins are an inseparable part of living organisms. Pterins participate in metabolic reactions mostly as tetrahydropterins. Dihydropterins are usually intermediates of these reactions, whereas oxidized pterins can be biomarkers of diseases. In this review, we analyze the available data on the quantum chemistry of unconjugated pterins as well as their photonics. This gives a comprehensive overview about the electronic structure of pterins and offers some benefits for biomedicine applications: (1) one can affect the enzymatic reactions of aromatic amino acid hydroxylases, NO synthases, and alkylglycerol monooxygenase through UV irradiation of H4pterins since UV provokes electron donor reactions of H4pterins; (2) the emission properties of H2pterins and oxidized pterins can be used in fluorescence diagnostics; (3) two-photon absorption (TPA) should be used in such pterin-related infrared therapy because single-photon absorption in the UV range is inefficient and scatters in vivo; (4) one can affect pathogen organisms through TPA excitation of H4pterin cofactors, such as the molybdenum cofactor, leading to its detachment from proteins and subsequent oxidation; (5) metal nanostructures can be used for the UV-vis, fluorescence, and Raman spectroscopy detection of pterin biomarkers. Therefore, we investigated both the biochemistry and physical chemistry of pterins and suggested some potential prospects for pterin-related biomedicine.