Tumor growth inhibition-overall survival modeling in non-small cell lung cancer: A case study from GEMSTONE-302.

Overall survival is vital for approving new anticancer drugs but is often impractical for early-phase studies. The tumor growth inhibition-overall survival (TGI-OS) model could bridge the gap between early- and late-stage development. This study aimed to identify an appropriate TGI-OS model for patients with non-small cell lung cancer from the GEMSTONE-302 study of sugemalimab. We used three TGI models to delineate tumor trajectories and investigated three OS model for linking TGI metric to OS. All three TGI models accurately captured tumor profiles at the individual level. The published atezolizumab-based TGI-OS model predicted survival time satisfactorily through simulation-based evaluation, whereas the other published model built from multi-treatment underestimated OS. Our study-specific TGI-OS model identified time-to-growth as the most significant metric with the number of metastatic sites and neutrophil-to-lymphocyte ratio at baseline as covariates and exhibited robust OS predictability. Our findings demonstrated the effectiveness of the TGI-OS models in predicting phase III outcomes, which underpins their value as a powerful tool for antitumor drug development.

The HSP40 family chaperone isoform DNAJB6b prevents neuronal cells from tau aggregation.

BACKGROUND: Alzheimer's disease (AD) is the most common neurodegenerative disorder with clinical presentations of progressive cognitive and memory deterioration. The pathologic hallmarks of AD include tau neurofibrillary tangles and amyloid plaque depositions in the hippocampus and associated neocortex. The neuronal aggregated tau observed in AD cells suggests that the protein folding problem is a major cause of AD. J-domain-containing proteins (JDPs) are the largest family of cochaperones, which play a vital role in specifying and directing HSP70 chaperone functions. JDPs bind substrates and deliver them to HSP70. The association of JDP and HSP70 opens the substrate-binding domain of HSP70 to help the loading of the clients. However, in the initial HSP70 cycle, which JDP delivers tau to the HSP70 system in neuronal cells remains unclear. RESULTS: We screened the requirement of a diverse panel of JDPs for preventing tau aggregation in the human neuroblastoma cell line SH-SY5Y by a filter retardation method. Interestingly, knockdown of DNAJB6, one of the JDPs, displayed tau aggregation and overexpression of DNAJB6b, one of the isoforms generated from the DNAJB6 gene by alternative splicing, reduced tau aggregation. Further, the tau bimolecular fluorescence complementation assay confirmed the DNAJB6b-dependent tau clearance. The co-immunoprecipitation and the proximity ligation assay demonstrated the protein-protein interaction between tau and the chaperone-cochaperone complex. The J-domain of DNAJB6b was critical for preventing tau aggregation. Moreover, reduced DNAJB6 expression and increased tau aggregation were detected in an age-dependent manner in immunohistochemical analysis of the hippocampus tissues of a mouse model of tau pathology. CONCLUSIONS: In summary, downregulation of DNAJB6b increases the insoluble form of tau, while overexpression of DNAJB6b reduces tau aggregation. Moreover, DNAJB6b associates with tau. Therefore, this study reveals that DNAJB6b is a direct sensor for its client tau in the HSP70 folding system in neuronal cells, thus helping to prevent AD.

Can a propensity score matching method be applied to assessing efficacy from single-arm proof-of-concept trials in oncology?

As a result of the escalating number of new cancer treatments being developed and competition among pharmaceutical companies, decisions regarding how to proceed with phase III trials are frequently based on findings from either single-arm phase I expansion cohorts or phase II studies that compare the efficacy of the study drug to a standard-of-care benchmark derived from historical data. However, even when eligibility criteria are matched, differences in the distribution of baseline patient features may influence the outcome of single-arm trials in real-world scenarios. Therefore, novel methods are needed to enhance the accuracy of efficacy prediction from current cohorts relative to historical data. In this study, we demonstrated the feasibility of using the propensity score matching (PSM) method to improve decision making by matching relevant baseline features between current and historical cohorts. According to our findings, utilizing the PSM method may provide a less biased means of comparing outcomes between current and historical cohorts relative to a naïve approach, which relies solely on differences in average outcomes between the cohorts.

A novel C19orf12 frameshift mutation in a MPAN pedigree impairs mitochondrial function and connectivity leading to neurodegeneration.

BACKGROUND: Mitochondrial membrane protein‒associated neurodegeneration (MPAN) is a rare genetic disease characterized by progressive neurodegeneration with brain iron accumulations combined with neuronal α-synuclein and tau aggregations. Mutations in C19orf12 have been associated with both autosomal recessive and autosomal dominant inheritance patterns of MPAN. METHODS: We present clinical features and functional evidence from a Taiwanese family with autosomal dominant MPAN caused by a novel heterozygous frameshift and nonsense mutation in C19orf12, c273_274 insA (p.P92Tfs*9). To verify the pathogenicity of the identified variant, we examined the mitochondrial function, morphology, protein aggregation, neuronal apoptosis, and RNA interactome in p.P92Tfs*9 mutant knock-in SH-SY5Y cells created with CRISPR-Cas9 technology. RESULTS: Clinically, the patients with the C19orf12 p.P92Tfs*9 mutation presented with generalized dystonia, retrocollis, cerebellar ataxia, and cognitive decline, starting in their mid-20s. The identified novel frameshift mutation is located in the evolutionarily conserved region of the last exon of C19orf12. In vitro studies revealed that the p.P92Tfs*9 variant is associated with impaired mitochondrial function, reduced ATP production, aberrant mitochondria interconnectivity and ultrastructure. Increased neuronal α-synuclein and tau aggregations, and apoptosis were observed under conditions of mitochondrial stress. Transcriptomic analysis revealed that the expression of genes in clusters related to mitochondrial fission, lipid metabolism, and iron homeostasis pathways was altered in the C19orf12 p.P92Tfs*9 mutant cells compared to control cells. CONCLUSION: Our findings provide clinical, genetic, and mechanistic insight revealing a novel heterozygous C19orf12 frameshift mutation to be a cause of autosomal dominant MPAN, further strengthening the importance of mitochondrial dysfunction in the pathogenesis of MPAN.

Effect of nanoparticle macroalgae in the treatment of fatty liver disease using logistic regression, and support vector machine.

One of the major health issues facing people worldwide is liver fibrosis. Liver fibrosis may be brought on by long-term exposure to harmful substances, medicines, and microorganisms. The development of liver fibrosis in children was particularly worrying due to their longer life-span, which was possibly related to a great risk of developing long-term complications. Marine algae species have provided a biological variety in the research phase of novel approaches to the treatment of numerous ailments. Marine macroalgae have recently been the subject of research due to their rich bioactive chemical composition and potential for the production of various nutraceuticals. Macroalgae are potentially excellent sources of bioactive substances with particular and distinct biological activity when compared to their terrestrial equivalents. Macroalgae in diverse marine cases offer a few biologically active metabolites, comprising sterols, polyunsaturated fatty acids, carotenoids, oligosaccharides, polysaccharides, proteins, polyphenols, vitamins, and minerals. Accordingly, there is great interest in their high potential for supporting immunomodulatory, antimicrobial, antidiabetic, antitumoral, anti-inflammatory, antiangiogenic, and neuroprotective properties. Using an experimental model, the current research intends to collect data on the therapeutic value of macroalgae nanoparticles for fatty liver disease. The researchers' goal of predicting illnesses from the extensive medical datasets is quite difficult. The purpose of this research is to assess the protective effects of a seaweed, Padina pavonia (PP), on liver fibrosis caused by carbon tetrachloride (CCl4). This research presents two models of logistic regression (LR) and support vector machines (SVM) for predicting the likelihood of liver disease incidence. The performance of the model was evaluated using a dataset. PP macro-algae considerably reduce the high blood concentrations of aminotransferases, alkaline phosphatases, and lactate dehydrogenases, as well as causing a considerable (p < 0.05) decrease in serum bilirubin levels. In addition to improving kidney function (urea and creatinine), algal extracts enhance fat metabolism (triglycerides and cholesterol). With an accuracy rate of 70.2%, a sensitivity of 92.3%, a specificity of 74.7%, a type I error of 9.1%, and a type II error of 21.0%, the predictive model has demonstrated excellent performance. The model validated laboratory tests' ability to predict illness (age; direct bilirubin (DB), total proteins (TP), and albumin (ALB). These classifier methods are compared on the basis of their execution time and classification accuracy.

Bone Marrow Histology in Hemophagocytic Lymphohistiocytosis.

CONTEXT.­: Bone marrow (BM) samples are obtained through aspiration and trephine biopsy. Hemophagocytic lymphohistiocytosis (HLH) has been largely studied in BM aspirate smears. OBJECTIVE.­: To investigate the histologic features of HLH in trephine biopsy. DESIGN.­: Patients with hemophagocytosis in BM aspirate smears were assigned to HLH (n = 127) and non-HLH (n = 203) groups. We quantified hematoxylin-eosin and CD68 immunohistochemical staining of their trephine biopsies. RESULTS.­: No significant correlation was noted in the hemophagocytosis count between aspirate smears and trephine biopsies. Compared with the non-HLH group, the HLH group had a higher hemophagocytosis count (13 versus 9 per tissue section, P = .046), lower percentage of the adipocytic area (36.7% versus 50.3%, P < .001), and higher percentage of the foamy area (19.1% versus 14.5%, P < .001). The HLH group had more histiocyte infiltrates (total histiocyte density, 9.2% versus 7.3%; P < .001) and more fat-infiltrating histiocytes (histiocyte density of the fat-associated part [HD-FA], 7.6% versus 6.2%; P < .001). We identified the following poor prognostic factors in the HLH group: age 50 years or older (median overall survival [mOS], 95 versus 499 days; P = .04), Epstein-Barr virus-positive T-cell lymphoproliferative diseases (EBV+TLPDs) (mOS, 51 versus 425 days; P < .001), hemophagocytosis count of 6 or higher per tissue section (mOS, 66 versus 435 days; P = .02), and HD-FA of 9% or greater (mOS, 61 versus 359 days; P = .02). Multivariate analysis revealed that age 50 years or older (hazard ratio [HR], 2.38; P < .001), EBV+TLPDs (HR, 2.07; P < .001), and hemophagocytosis count of 6 or higher per tissue section (HR, 2.07; P = .002) were independent prognostic factors for HLH. CONCLUSIONS.­: The HLH group had higher hemophagocytic activity, higher cellularity, a more foamy appearance, more histiocyte infiltrates, and more fat-infiltrating histiocytes. High hemophagocytic activity and marked histiocyte infiltrates in the BM fat were associated with poorer prognosis.

[Clinical features of 19 children infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 in Hangzhou, China]. / 杭州市19ä¾‹æ–°åž‹å† çŠ¶ç— æ¯’Omicronå˜å¼‚æ ªæ„ŸæŸ“å„¿ç«¥çš„ä¸´åºŠç‰¹å¾.

OBJECTIVES: To study the clinical features of children infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: The medical data of 19 children who were diagnosed with SARS-CoV-2 Omicron variant infection from January 28 to March 3, 2022 in Hangzhou were retrospectively reviewed. RESULTS: Among the 19 children, there were 7 boys (37%) and 12 girls (63%), and their age ranged from 6 months to 16 years, with a median age of 2 years and 1 month. Most of these children were infants and young children (aged ≤3 years, accounting for 53%). Among these children, 11 (58%) were unvaccinated with SARS-CoV-2 vaccine and 8 (42%) were vaccinated with SARS-CoV-2 vaccine, and 3 children (16%) had a history of underlying diseases. All 19 children had a clear history of close contact with persons infected with SARS-CoV-2, and 10 children (53%) were involved in the cluster outbreak in a maternal and infant care center. In terms of clinical classification, 13 children (68%) had mild coronavirus disease 2019 (COVID-19) and 6 (32%) had common COVID-19, with no severe cases of COVID-19. The most common clinical symptoms were cough (100%) and fever (63%). The children with a normal peripheral white blood cell count accounted for 84%, and those with a normal lymphocyte count accounted for 68%. There were no significant abnormalities in platelet count, procalcitonin, liver function parameters (alanine aminotransferase and aspartate aminotransferase), and renal function parameters (creatinine and urea). Six children (32%) had obvious signs of pneumonia on chest CT. All 19 children were given symptomatic treatment, and 12 children (63%) were given aerosol inhalation of interferon α. All children were cured and discharged. CONCLUSIONS: Children infected with Omicron variant strains are more common in infants and young children, with mild symptoms and good prognosis. Most of the children have a history of close contact with persons infected with SARS-CoV-2, and epidemic prevention and control should be strengthened in places with many infants and children, such as maternal and infant care centers.

Evaluation of opioid consumption trends for pain in Taiwan and comparison with neighboring Asian countries.

Opioids are effective analgesics for pain relief, however, inappropriate use may cause risks. The aims of the study were to evaluate trends of opioid consumption for pain management in Taiwan and compare them among neighboring Asian countries. Opioid consumption data, including fentanyl, morphine, oxycodone, hydromorphone, codeine, and pethidine, were collected from the Controlled Drugs Management Information System of Taiwan Food and Drug Administration from 2008 to 2018. Data of different continents and neighboring Asian countries were retrieved from the WHO website. The major findings include: (1) In Taiwan, the total annual opioid consumption has gradually increased from 2008 to 2018, with fentanyl being the most frequently consumed opioid analgesic, followed by morphine. Codeine and pethidine consumption dropped significantly over the years. (2) In neighboring Asian countries, the opioid consumption in order from highest to lowest consumption were South Korea, Japan, Taiwan, Singapore, Hong Kong (China), and China. We concluded that, from 2008 to 2018, the total opioid consumption trend for pain management in Taiwan has slowly increased, with fentanyl and morphine being the most commonly used opioids. When compared with neighboring Asian countries, level of opioid consumption in Taiwan was between Japan and Singapore. The research results may provide a reference for healthcare professionals worldwide.

Syndrome of Inappropriate Secretion of Antidiuretic Hormone Associated With Varicella Infection in Children.

A 9-year-old girl with remarkable hyponatremia was diagnosed with SIADH that was likely secondary to varicella. Under appropriate treatment, her serum sodium returned to the normal level. There was no evidence of hyponatremia at a 3-month follow-up. We propose that medical professionals need to consider the existence of that SIADH when treating patients with varicella who present with severe hyponatremia.

Prevalence of opioid prescriptions in Taiwan (2008-2018).

BACKGROUND: Opioids are effective for severe pain; however, the safety issue is also a primary concern. To better understand the opioid use in Taiwan, we conducted this study. METHODS: Data on patients with opioid prescriptions, including morphine, fentanyl, pethidine, codeine, oxycodone, hydromorphone, and buprenorphine were collected using the Taiwan National Health Insurance Database (NHID). RESULTS: Our analysis of opioid prescriptions from 2008 to 2018 in Taiwan indicated that (1) A slow increase in prevalence of opioid prescription was found during the study period. Among the drugs studied, morphine accounted for the majority of the prescriptions written, with a gradual increase annually. Pethidine prescriptions showed a significant and rapid decline over the years; (2) medical centers prescribed the largest number of opioids, followed by regional hospitals, local hospitals, and clinics; (3) the number of prescriptions per year per capita in cancer group was much higher than that in noncancer group. In noncancer group, most of the prescriptions were used in acute pain service (98.7%); and (4) use of opioids increased with age in both cancer and noncancer patients. CONCLUSION: The total number of opioid prescriptions in Taiwan gradually increased annually, among which morphine was the most commonly used opioid. Cancer patients consumed more opioid prescriptions than noncancer patients and most of the prescriptions in noncancer patients were used in acute pain service. The number of prescriptions increased with the age of the patients in both cancer and noncancer patients. The low prescription rate of opioids in chronic pain in Taiwan is not similar as those in high opioid-consuming countries, such as United States.

Bandgap Shrinkage and Charge Transfer in 2D Layered SnS2 Doped with V for Photocatalytic Efficiency Improvement.

Effects of electronic and atomic structures of V-doped 2D layered SnS2 are studied using X-ray spectroscopy for the development of photocatalytic/photovoltaic applications. Extended X-ray absorption fine structure measurements at V K-edge reveal the presence of VO and VS bonds which form the intercalation of tetrahedral OVS sites in the van der Waals (vdW) gap of SnS2 layers. X-ray absorption near-edge structure (XANES) reveals not only valence state of V dopant in SnS2 is ≈4+ but also the charge transfer (CT) from V to ligands, supported by V Lα,ß resonant inelastic X-ray scattering. These results suggest V doping produces extra interlayer covalent interactions and additional conducting channels, which increase the electronic conductivity and CT. This gives rapid transport of photo-excited electrons and effective carrier separation in layered SnS2 . Additionally, valence-band photoemission spectra and S K-edge XANES indicate that the density of states near/at valence-band maximum is shifted to lower binding energy in V-doped SnS2 compare to pristine SnS2 and exhibits band gap shrinkage. These findings support first-principles density functional theory calculations of the interstitially tetrahedral OVS site intercalated in the vdW gap, highlighting the CT from V to ligands in V-doped SnS2 .

An HSP90 cochaperone Ids2 maintains the stability of mitochondrial DNA and ATP synthase.

BACKGROUND: Proteostasis unbalance and mitochondrial dysfunction are two hallmarks of aging. While the chaperone folds and activates its clients, it is the cochaperone that determines the specificity of the clients. Ids2 is an HSP90's cochaperone controlling mitochondrial functions, but no in vivo clients of Ids2 have been reported yet. RESULTS: We performed a screen of the databases of HSP90 physical interactors, mitochondrial components, and mutants with respiratory defect, and identified Atp3, a subunit of the complex V ATP synthase, as a client of Ids2. Deletion of IDS2 destabilizes Atp3, and an α-helix at the middle region of Ids2 recruits Atp3 to the folding system. Shortage of Ids2 or Atp3 leads to the loss of mitochondrial DNA. The intermembrane space protease Yme1 is critical to maintaining the Atp3 protein level. Moreover, Ids2 is highly induced when cells carry out oxidative respiration. CONCLUSIONS: These findings discover a cochaperone essentially for maintaining the stability of mitochondrial DNA and the proteostasis of the electron transport chain-crosstalk between two hallmarks of aging.

A Clinicopathological Study of Cytomegalovirus Lymphadenitis and Tonsillitis and Their Association with Epstein-Barr Virus.

INTRODUCTION: Histopathological characteristics of cytomegalovirus (CMV) lymphadenitis have been well described. Rare studies have reported the immune status and clinical features. Clinically, experts believed that CMV lymphadenitis develops in immunocompromised and immunocompetent patients. Infectious mononucleosis (IM)-like syndrome is the most well-known clinical presentation. METHODS: We reviewed archived CMV immunohistochemical stains on lymphoid tissues. The clinicopathological features of CMV-positive cases were studied. RESULTS: For lymph nodes, we detected CMV in 29% (5/17) allogeneic peripheral blood hematopoietic stem cell transplantation (PBSCT) recipients, 29% (4/14) post-autologous PBSCT patients, 13% (6/47) patients treated with intravenous chemotherapy, and 9% (9/96) immunocompetent patients. We detected CMV in 7% (2/24) of tonsils but not in the nasopharynx, tongue base, or spleen specimens. The patients with iatrogenic immunodeficiency ranged from 37 to 76 years old. CMV infections developed a few years after lymphoma treatment (median duration after allogeneic PBSCT, 932 days; after autologous PBSCT, 370 days; and after chemotherapy, 626 days). The most common clinical presentation was neck mass (13/25, 42%), followed by asymptomatic image finding (10/25, 40%). Positron emission tomography/computed tomography (PET/CT) scan showed increased uptake compared to the liver in all patients (11/11, 100%). Of 10 lymphoma patients, 8 (80%) had a Deauville score of 4-5; they accounted for 30% (8/27) of lymphoma patients with false-positive PET/CT scan results. All cases were self-limiting. 96% (23/25) cases had Epstein-Barr virus coinfection, and EBER-positive cells were predominantly in a few germinal centers. CONCLUSIONS: Cytomegalovirus (CMV) lymphadenitis and tonsillitis were subclinical infections, not primary CMV infection with IM-like syndrome. The lymphadenopathy typically developed a few years after lymphoma treatments in the middle-aged and the elderly. The lesions mimicked lymphoma relapse in PET scans. Therefore, recognizing CMV infection in lymphoid tissues is of clinical importance.

Clinical and functional characterization of a novel STUB1 frameshift mutation in autosomal dominant spinocerebellar ataxia type 48 (SCA48).

BACKGROUND: Heterozygous pathogenic variants in STUB1 are implicated in autosomal dominant spinocerebellar ataxia type 48 (SCA48), which is a rare familial ataxia disorder. We investigated the clinical, genetic and functional characteristics of STUB1 mutations identified from a Taiwanese ataxia cohort. METHODS: We performed whole genome sequencing in a genetically undiagnosed family with an autosomal dominant ataxia syndrome. Further Sanger sequencing of all exons and intron-exon boundary junctions of STUB1 in 249 unrelated patients with cerebellar ataxia was performed. The pathogenicity of the identified novel STUB1 variant was investigated. RESULTS: We identified a novel heterozygous frameshift variant, c.832del (p.Glu278fs), in STUB1 in two patients from the same family. This rare mutation is located in the U-box of the carboxyl terminus of the Hsc70-interacting protein (CHIP) protein, which is encoded by STUB1. Further in vitro experiments demonstrated that this novel heterozygous STUB1 frameshift variant impairs the CHIP protein's activity and its interaction with the E2 ubiquitin ligase, UbE2D1, leading to neuronal accumulation of tau and α-synuclein, caspase-3 activation, and promoting cellular apoptosis through a dominant-negative pathogenic effect. The in vivo study revealed the influence of the CHIP expression level on the differentiation and migration of cerebellar granule neuron progenitors during cerebellar development. CONCLUSIONS: Our findings provide clinical, genetic, and a mechanistic insight linking the novel heterozygous STUB1 frameshift mutation at the highly conserved U-box domain of CHIP as the cause of autosomal dominant SCA48. Our results further stress the importance of CHIP activity in neuronal protein homeostasis and cerebellar functions.

Nuclear envelope tethering inhibits the formation of ALT-associated PML bodies in ALT cells.

Telomere length homeostasis is essential for maintaining genomic stability and cancer proliferation. Telomerase-negative cancer cells undergo recombination-mediated alternative lengthening of telomeres. Telomeres associate with the nuclear envelope through the shelterin RAP1 and nuclear envelope SUN1 proteins. However, how the associations between telomeres and the nuclear envelope affect the progression of telomere recombination is not understood. Here, we show that telomere anchorage might inhibit telomere-telomere recombination. SUN1 depletion stimulates the formation of alternative lengthening of telomeres-associated promyelocytic leukemia bodies in ALT cells. In contrast, overexpression of a telomere-nuclear envelope-tethering chimera protein, RAP1-SUN1, suppresses APB formation. Moreover, inhibition of this nuclear envelope attachment alleviates the requirement of TOP3α for resolving the supercoiling pressure during telomere recombination. A coimmunoprecipitation assay revealed that the SUN1 N-terminal nucleoplasmic domain interacts with the RAP1 middle coil domain, and phosphorylation-mimetic mutations in RAP1 inhibit this interaction. However, abolishing the RAP1-SUN1 interaction does not hinder APB formation, which hints at the existence of another SUN1-dependent telomere anchorage pathway. In summary, our results reveal an inhibitory role of telomere-nuclear envelope association in telomere-telomere recombination and imply the presence of redundant pathways for the telomere-nuclear envelope association in ALT cells.

Stress-induced p53 drives BAG5 cochaperone expression to control α-synuclein aggregation in Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disorder with the pathological hallmark of α-synuclein aggregation. Dysregulation of α-synuclein homeostasis caused by aging, genetic, and environmental factors underlies the pathogenesis of PD. While chaperones are essential for proteostasis, whether modulation of cochaperones may participate in PD formation has not been fully characterized. Here, we assessed the expression of several HSP70- and HSP90-related factors under various stresses and found that BAG5 expression is distinctively elevated in etoposide- or H2O2-treated SH-SY5Y cells. Stress-induced p53 binds to the BAG5 promoter directly to stimulate BAG5. Induced BAG5 binds α-synuclein and HSP70 in both cell cultures and brain lysates from PD patients. Overexpressed BAG5 may result in the loss of its ability to promote HSP70. Importantly, α-synuclein aggregation in SH-SY5Y cells requires BAG5. BAG5 expression is also detected in transgenic SNCA mutant mice and in PD patients. Together, our data reveal stress-induced p53-BAG5-HSP70 regulation that provides a potential therapeutic angle for PD.

Hexafluorotitanic acid-assisted synthesis of large-sized, ultrathin titania nanosheets as multifunctional and high-performance photocatalysts.

A fast cyclohexanol solvothermal pathway was developed to prepare highly dispersed anatase titania (TiO2) nanosheets with an edge length of ∼800 nm and a thickness of ∼6 nm. Under the synergistic control of hexafluorotitanic acid and cyclohexanol, the exposed 001 facets reached ∼98.5% on the TiO2 nanosheets obtained by the treatment at 180 °C for 150 min. Moreover, it was found that the phase transformation and structural development drastically occurred during the solvothermal treatment. When used as a catalyst for photodegradation of rhodamine B, the TiO2 nanosheets exhibited a good recycling stability and a much higher photocatalytic degradation rate (nearly 99% degradation within 2.5 h) than the commercial P25 (93.6%). After being uniformly loaded with 4 wt.% of the Pt nanoparticles, the TiO2 nanosheets displayed a photocatalytic hydrogen production rate of 2.239 mmol g-1 h-1 under simulated solar light, which was much higher than the pristine TiO2 nanosheets (0.045 mmol g-1 h-1) as well as most of the reported TiO2-based photocatalysts. The remarkable photocatalytic activity and good stability of the TiO2 nanosheets with highly exposed 001 facets would make them find potential applications in both water treatment and hydrogen generation from water splitting under solar light.

Selected ellipticine derivatives, known to target topoisomerase II, suppress the alternative lengthening of telomere (ALT) pathway in telomerase-negative cells.

BACKGROUND: DNA topoisomerase and telomerase enzymes are popular targets of several anti-tumor drugs. Smooth proceeding of telomeric recombination requires Topoisomerase II (Top2), which is involved in telomere-telomere recombination through functioning in relaxation of positive supercoils among the cells adopting telomerase-independent Alternative lengthening of telomere (ALT) pathway. Most of the inhibitors reported so far have been designed to targetsolely telomerase-positive cells, which can potentially lead to therapeutic failure because tumor cells treated with telomerase inhibitors can activate the ALT pathway for telomere maintenance. Knowing that ALT cells are more sensitive against a Top2 inhibitor, ICRF-93 agent, compared to telomerase-positive cells, we analyzed two selected ellipticine derivatives that we recently reported as TopII-targeting compounds, to assess their effects on the formation of DNA breaks and suppression of ALT pathway. METHODS: Cell viability, Comet, C-Circle assays, dot blot, immunofluorescence staining, and telomere fluorescence in situ hybridization (FISH) staining were used for determining the effect of the compounds on ALT status of tumor cells. RESULTS AND CONCLUSIONS: Treatment of ALT cells with ellipticine derivatives resulted in the formation of DNA breaks and suppression of ALT-associated phenotypes in vitro. Our results will contribute to the development of therapeutic strategies combining telomerase and ALT pathway inhibitors.

Glucose intake hampers PKA-regulated HSP90 chaperone activity.

Aging is an intricate phenomenon associated with the gradual loss of physiological functions, and both nutrient sensing and proteostasis control lifespan. Although multiple approaches have facilitated the identification of candidate genes that govern longevity, the molecular mechanisms that link aging pathways are still elusive. Here, we conducted a quantitative mass spectrometry screen and identified all phosphorylation/dephosphorylation sites on yeast proteins that significantly responded to calorie restriction, a well-established approach to extend lifespan. Functional screening of 135 potential regulators uncovered that Ids2 is activated by PP2C under CR and inactivated by PKA under glucose intake. ids2Δ or ids2 phosphomimetic cells displayed heat sensitivity and lifespan shortening. Ids2 serves as a co-chaperone to form a complex with Hsc82 or the redundant Hsp82, and phosphorylation impedes its association with chaperone HSP90. Thus, PP2C and PKA may orchestrate glucose sensing and protein folding to enable cells to maintain protein quality for sustained longevity.

PARP1 controls KLF4-mediated telomerase expression in stem cells and cancer cells.

Telomerase is highly expressed in cancer and embryonic stem cells (ESCs) and implicated in controlling genome integrity, cancer formation and stemness. Previous studies identified that Krüppel-like transcription factor 4 (KLF4) activates telomerase reverse transcriptase (TERT) expression and contributes to the maintenance of self-renewal in ESCs. However, little is known about how KLF4 regulates TERT expression. Here, we discover poly(ADP-ribose) polymerase 1 (PARP1) as a novel KLF4-interacting partner. Knockdown of PARP1 reduces TERT expression and telomerase activity not only in cancer cells, but also in human and mouse ESCs. Recruitment of KLF4 to TERT promoter is reduced in PARP1-suppressed cells. The poly(ADP-ribose) polymerase activity is dispensable, while the oligo(ADP-ribose) polymerase activity is required for the PARP1- and KLF4-mediated TERT activation. Repression of Parp1 in mouse ESCs decreases expression of pluripotent markers and induces differentiation. These results suggest that PARP1 recruits KLF4 to activate telomerase expression and stem cell pluripotency, indicating a positive regulatory role of the PARP1-KLF4 complex in telomerase expression in cancer and stem cells.