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1.
Clin Nutr ESPEN ; 61: 52-62, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38777473

ABSTRACT

BACKGROUND & AIM: Malnutrition, risk of malnutrition, and risk factors for malnutrition are prevalent among acutely admitted medical patients aged ≥65 years and have significant health-related consequences. Consequently, we aimed to investigate the effectiveness of a multidisciplinary and transitional nutritional intervention on health-related quality of life compared with standard care. METHODS: The study was a block randomized, observer-blinded clinical trial with two parallel arms. The Intervention Group was offered a multidisciplinary transitional nutritional intervention consisting of dietary counselling and six sub-interventions targeting individually assessed risk factors for malnutrition, while the Control Group received standard care. The inclusion criteria were a Mini Nutritional Assessment Short-Form score ≤11, age ≥65 years, and an acute admittance to the Emergency Department. Outcomes were assessed on admission and 8 and 16 weeks after hospital discharge. The primary outcome was the difference between groups in change in health-related quality of life (assessed by the EuroQol-5D-5L) from baseline to 16 weeks after discharge. The secondary outcomes were difference in intake of energy and protein, well-being, muscle strength, and body weight at all timepoints. RESULTS: From October 2018 to April 2021, 130 participants were included. Sixteen weeks after discharge, 29% in the Intervention Group and 19% in the Control Group were lost to follow-up. Compliance varied between the sub-interventions targeting nutritional risk factors and was generally low after discharge, ranging from 0 to 61%. No difference was found between groups on change in health-related quality of life or on well-being, muscle strength, and body weight at any timepoint, neither using the intention-to-treat analysis nor the per-protocol analysis. The protein intake was higher in the Intervention Group during hospitalization (1.1 (Standard Deviation (SD) 0.4) vs 0.8 (SD 0.5) g/kg/day, p = 0.0092) and 8 weeks after discharge (1.2 (SD 0.5) vs 0.9 (0.4) g/kg/day, p = 0.0025). The percentual intake of calculated protein requirements (82% (SD 24) vs 61% (SD 32), p = 0.0021), but not of calculated energy requirements (89% (SD 23) vs 80% (SD 37), p = 0.2), was higher in the Intervention Group than in the Control Group during hospitalization. Additionally, the Intervention Group had a significantly higher percentual intake of calculated protein requirements (94% (SD 41) vs 74% (SD 30), p = 0.015) and calculated energy requirements (115% (SD 37) vs 94% (SD 31), p = 0.0070) 8 weeks after discharge. The intake of energy and protein was comparable between the groups 16 weeks after discharge. CONCLUSION: We found no effect of a multidisciplinary and transitional nutritional intervention for acutely admitted medical patients aged ≥65 years with malnutrition or risk of malnutrition on our primary outcome, health-related quality of life 16 weeks after discharge. Nor did the intervention affect the secondary outcomes, well-being, muscle strength, and body weight from admission to 8 or 16 weeks after discharge. However, the intervention improved energy and protein intake during hospitalization and 8 weeks after discharge. Low compliance with the intervention after discharge may have compromised the effect of the intervention. The study is registered at ClinicalTrials.gov (identifier: NCT03741283).


Subject(s)
Malnutrition , Nutrition Assessment , Quality of Life , Humans , Aged , Male , Female , Malnutrition/prevention & control , Aged, 80 and over , Nutritional Status , Risk Factors , Hospitalization , Geriatric Assessment , Nutrition Therapy/methods , Treatment Outcome
2.
Front Immunol ; 14: 1138920, 2023.
Article in English | MEDLINE | ID: mdl-37346039

ABSTRACT

Introduction: Inhibitors of the ATR kinase act as radiosensitizers through abrogating the G2 checkpoint and reducing DNA repair. Recent studies suggest that ATR inhibitors can also increase radiation-induced antitumor immunity, but the underlying immunomodulating mechanisms remain poorly understood. Moreover, it is poorly known how such immune effects relate to different death pathways such as caspase-dependent apoptosis. Here we address whether ATR inhibition in combination with irradiation may increase the presentation of hallmark factors of immunogenic cell death (ICD), and to what extent caspase activation regulates this response. Methods: Human lung cancer and osteosarcoma cell lines (SW900, H1975, H460, U2OS) were treated with X-rays and ATR inhibitors (VE822; AZD6738) in the absence and presence of a pan-caspase inhibitor. The ICD hallmarks HMGB1 release, ATP secretion and calreticulin surface-presentation were assessed by immunoblotting of growth medium, the CellTiter-Glo assay and an optimized live-cell flow cytometry assay, respectively. To obtain accurate measurement of small differences in the calreticulin signal by flow cytometry, we included normalization to a barcoded control sample. Results: Extracellular release of HMGB1 was increased in all the cell lines at 72 hours after the combined treatment with radiation and ATR inhibitors, relative to mock treatment or cells treated with radiation alone. The HMGB1 release correlated largely - but not strictly - with loss of plasma membrane integrity, and was suppressed by addition of the caspase inhibitor. However, one cell line showed HMGB1 release despite caspase inhibition, and in this cell line caspase inhibition induced pMLKL, a marker for necroptosis. ATP secretion occurred already at 48 hours after the co-treatment and did clearly not correlate with loss of plasma membrane integrity. Addition of pan-caspase inhibition further increased the ATP secretion. Surface-presentation of calreticulin was increased at 24-72 hours after irradiation, but not further increased by either ATR or caspase inhibition. Conclusion: These results show that ATR inhibition can increase the presentation of two out of three ICD hallmark factors from irradiated human cancer cells. Moreover, caspase activation distinctly affects each of the hallmark factors, and therefore likely plays a dual role in tumor immunogenicity by promoting both immunostimulatory and -suppressive effects.


Subject(s)
Caspases , HMGB1 Protein , Humans , Caspases/metabolism , HMGB1 Protein/metabolism , Calreticulin/metabolism , Caspase Inhibitors , Immunogenic Cell Death , Cell Line, Tumor , Protein Kinase Inhibitors , Adenosine Triphosphate , Ataxia Telangiectasia Mutated Proteins/metabolism
3.
Bio Protoc ; 13(8): e4659, 2023 Apr 20.
Article in English | MEDLINE | ID: mdl-37113330

ABSTRACT

RNA polymerase II (RNAPII) transcribes DNA into mRNA and thereby plays a critical role in cellular protein production. In addition, RNAPII plays a central role in DNA damage responses. Measurements of RNAPII on chromatin may thus give insight into several essential processes in eukaryotic cells. During transcription, the C-terminal domain of RNAPII becomes post-translationally modified, and phosphorylation on serine 5 and serine 2 can be used as markers for the promoter proximal and productively elongating forms of RNAPII, respectively. Here, we provide a detailed protocol for the detection of chromatin-bound RNAPII and its serine 5- and serine 2-phosphorylated forms in individual human cells through the cell cycle. We have recently shown that this method can be used to study the effects of ultraviolet DNA damage on RNAPII chromatin binding and that it can even be used to reveal new knowledge about the transcription cycle itself. Other commonly used methods to study RNAPII chromatin binding include chromatin immunoprecipitation followed by sequencing or chromatin fractionation followed by western blotting. However, such methods are frequently based on lysates made from a large number of cells, which may mask population heterogeneity, e.g., due to cell cycle phase. With strengths such as single-cell analysis, speed of use, and accurate quantitative readouts, we envision that our flow cytometry method can be widely used as a complementary approach to sequencing-based methods to study effects of different stimuli and inhibitors on RNAPII-mediated transcription. Graphical overview.

4.
Int J Radiat Biol ; 99(6): 941-950, 2023.
Article in English | MEDLINE | ID: mdl-33877959

ABSTRACT

PURPOSE: Radiation-induced activation of cell cycle checkpoints have been of long-standing interest. The WEE1, CHK1 and ATR kinases are key factors in cell cycle checkpoint regulation and are essential for the S and G2 checkpoints. Here, we review the rationale for why inhibitors of WEE1, CHK1 and ATR could be beneficial in combination with radiation. CONCLUSIONS: Combined treatment with radiation and inhibitors of these kinases results in checkpoint abrogation and subsequent mitotic catastrophe. This might selectively radiosensitize tumor cells, as they often lack the p53-dependent G1 checkpoint and therefore rely more on the G2 checkpoint to repair DNA damage. Further affecting the repair of radiation damage, inhibition of WEE1, CHK1 or ATR also specifically suppresses the homologous recombination repair pathway. Moreover, inhibition of these kinases can induce massive replication stress during S phase of the cell cycle, likely contributing to eliminate radioresistant S phase cells. Intriguingly, recent findings suggest that cell cycle checkpoint inhibitors in combination with radiation can also enhance anti-tumor immune effects. Altogether, the expanding knowledge about the functional roles of WEE1, CHK1 and ATR inhibitors support that they are promising candidates for use in combination with radiation treatment.


Subject(s)
Protein-Tyrosine Kinases , Radiation Oncology , Protein-Tyrosine Kinases/genetics , Protein-Tyrosine Kinases/metabolism , Cell Cycle Proteins/genetics , Nuclear Proteins/metabolism , Cell Cycle , Cell Cycle Checkpoints , DNA Damage , G2 Phase Cell Cycle Checkpoints , Cell Line, Tumor , Ataxia Telangiectasia Mutated Proteins/genetics
5.
Front Oncol ; 12: 981332, 2022.
Article in English | MEDLINE | ID: mdl-36387237

ABSTRACT

Recent studies suggest that inhibition of the ATR kinase can potentiate radiation-induced antitumor immune responses, but the extent and mechanisms of such responses in human cancers remain scarcely understood. We aimed to assess whether the ATR inhibitors VE822 and AZD6738, by abrogating the G2 checkpoint, increase cGAS-mediated type I IFN response after irradiation in human lung cancer and osteosarcoma cell lines. Supporting that the checkpoint may prevent IFN induction, radiation-induced IFN signaling declined when the G2 checkpoint arrest was prolonged at high radiation doses. G2 checkpoint abrogation after co-treatment with radiation and ATR inhibitors was accompanied by increased radiation-induced IFN signaling in four out of five cell lines tested. Consistent with the hypothesis that the cytosolic DNA sensor cGAS may detect DNA from ruptured micronuclei after G2 checkpoint abrogation, cGAS co-localized with micronuclei, and depletion of cGAS or STING abolished the IFN responses. Contrastingly, one lung cancer cell line showed no increase in IFN signaling despite irradiation and G2 checkpoint abrogation. This cell line showed a higher level of the exonuclease TREX1 than the other cell lines, but TREX1 depletion did not enhance IFN signaling. Rather, addition of a pan-caspase inhibitor restored the IFN response in this cell line and also increased the responses in the other cell lines. These results show that treatment-induced caspase activation can suppress the IFN response after co-treatment with radiation and ATR inhibitors. Caspase activation thus warrants further consideration as a possible predictive marker for lack of IFN signaling.

6.
Nucleic Acids Res ; 50(15): e89, 2022 08 26.
Article in English | MEDLINE | ID: mdl-35641102

ABSTRACT

RNA polymerase II (RNAPII) is emerging as an important factor in DNA damage responses, but how it responds to genotoxic stress is not fully understood. We have developed a rapid and sensitive flow cytometry method to study chromatin binding of RNAPII in individual human cells through the cell cycle. Indicating enhanced transcription initiation at early timepoints, levels of RNAPII were increased at 15-30min after UV-induced DNA damage. This was particularly evident for the S5 phosphorylated form of RNAPII (pRNAPII S5), which is typically associated with promoter proximal pausing. Furthermore, degradation of pRNAPII S5 frequently occurs, as its levels on chromatin were strongly enhanced by the proteasome inhibitor MG132 with and without UV. Remarkably, inhibiting pause release with 5,6-dichloro-1-beta-ribo-furanosyl benzimidazole (DRB) further promoted UV-induced degradation of pRNAPII S5, suggesting enhanced initiation may lead to a phenomenon of 'promoter proximal crowding' resulting in premature termination via degradation of RNAPII. Moreover, pRNAPII S2 levels on chromatin were more stable in S phase of the cell cycle 2h after UV, indicating cell cycle specific effects. Altogether our results demonstrate a useful new method and suggest that degradation of promoter proximal RNAPII plays an unanticipated large role both during normal transcription and after UV.


Subject(s)
Chromatin , Flow Cytometry/methods , RNA Polymerase II , Chromatin/genetics , DNA Damage , Humans , Promoter Regions, Genetic , RNA Polymerase II/metabolism , Single-Cell Analysis , Transcription, Genetic
7.
Cancers (Basel) ; 13(15)2021 Jul 28.
Article in English | MEDLINE | ID: mdl-34359691

ABSTRACT

Inhibitors of WEE1 and ATR kinases are considered promising for cancer treatment, either as monotherapy or in combination with chemo- or radiotherapy. Here, we addressed whether simultaneous inhibition of WEE1 and ATR might be advantageous. Effects of the WEE1 inhibitor MK1775 and ATR inhibitor VE822 were investigated in U2OS osteosarcoma cells and in four lung cancer cell lines, H460, A549, H1975, and SW900, with different sensitivities to the WEE1 inhibitor. Despite the differences in cytotoxic effects, the WEE1 inhibitor reduced the inhibitory phosphorylation of CDK, leading to increased CDK activity accompanied by ATR activation in all cell lines. However, combining ATR inhibition with WEE1 inhibition could not fully compensate for cell resistance to the WEE1 inhibitor and reduced cell viability to a variable extent. The decreased cell viability upon the combined treatment correlated with a synergistic induction of DNA damage in S-phase in U2OS cells but not in the lung cancer cells. Moreover, less synergy was found between ATR and WEE1 inhibitors upon co-treatment with radiation, suggesting that single inhibitors may be preferable together with radiotherapy. Altogether, our results support that combining WEE1 and ATR inhibitors may be beneficial for cancer treatment in some cases, but also highlight that the effects vary between cancer cell lines.

8.
Ann Fam Med ; 19(3): 224-231, 2021.
Article in English | MEDLINE | ID: mdl-34180842

ABSTRACT

PURPOSE: Primary care providers (PCPs) may feel ill-equipped to effectively and safely manage patients with chronic pain, an addiction, or both. This study evaluated a multidisciplinary approach of supporting PCPs in their management of this psychosocially complex patient population, to inform subsequent strategies clinics can use to support PCPs. METHODS: Four years ago, at our academic community health safety-net system, we created a multidisciplinary consultation service to support PCPs in caring for complex patients with pain and addiction. We collected and thematically analyzed 66 referral questions to understand PCPs' initially expressed needs, interviewed 14 referring PCPs to understand their actual needs that became apparent during the consultation, and identified discrepancies between these sets of needs. RESULTS: Many of the PCPs' expressed needs aligned with their actual needs, including needing expertise in the areas of addiction, safe prescribing of opioids, nonopioid treatment options, and communication strategies for difficult conversations, a comprehensive review of the case, and a biopsychosocial approach to management. But several PCP needs emerged after the initial consultation that they did not initially anticipate, including confirming their medical decision-making process, emotional validation, feeling more control, having an outside entity take the burden off the PCP for management decisions, boundary setting, and reframing the visit to focus on the patient's function, values, and goals. CONCLUSIONS: A multidisciplinary consultation service can act as a mechanism to meet the needs of PCPs caring for psychosocially complex patients with pain and addiction, including unanticipated needs. Future research should explore the most effective ways to meet PCP needs across populations and health systems.


Subject(s)
Chronic Pain , Physicians, Primary Care , Attitude of Health Personnel , Chronic Pain/therapy , Humans , Primary Health Care , Qualitative Research , Referral and Consultation
9.
Mol Cell Oncol ; 8(3): 1910008, 2021 Apr 18.
Article in English | MEDLINE | ID: mdl-34027044

ABSTRACT

Conflicts between transcription and replication are a major source of replication stress. Our recent findings show that proper dephosphorylation of Serine 5 in the carboxy-terminal domain (CTD) of DNA-directed RNA polymerase II subunit RPB1 is needed to prevent such conflicts in human cells.

10.
Cell Rep ; 33(9): 108469, 2020 12 01.
Article in English | MEDLINE | ID: mdl-33264625

ABSTRACT

Transcription-replication (T-R) conflicts cause replication stress and loss of genome integrity. However, the transcription-related processes that restrain such conflicts are poorly understood. Here, we demonstrate that the RNA polymerase II (RNAPII) C-terminal domain (CTD) phosphatase protein phosphatase 1 (PP1) nuclear targeting subunit (PNUTS)-PP1 inhibits replication stress. Depletion of PNUTS causes lower EdU uptake, S phase accumulation, and slower replication fork rates. In addition, the PNUTS binding partner WDR82 also promotes RNAPII-CTD dephosphorylation and suppresses replication stress. RNAPII has a longer residence time on chromatin after depletion of PNUTS or WDR82. Furthermore, the RNAPII residence time is greatly enhanced by proteasome inhibition in control cells but less so in PNUTS- or WDR82-depleted cells, indicating that PNUTS and WDR82 promote degradation of RNAPII on chromatin. Notably, reduced replication is dependent on transcription and the phospho-CTD binding protein CDC73 after depletion of PNUTS/WDR82. Altogether, our results suggest that RNAPII-CTD dephosphorylation is required for the continuous turnover of RNAPII on chromatin, thereby preventing T-R conflicts.


Subject(s)
Chromatin/drug effects , Chromosomal Proteins, Non-Histone/therapeutic use , RNA Polymerase II/metabolism , Chromosomal Proteins, Non-Histone/pharmacology , Humans , Transfection
11.
Front Oncol ; 9: 1301, 2019.
Article in English | MEDLINE | ID: mdl-31850205

ABSTRACT

The CD37 targeting radioimmunoconjugate 177Lu-lilotomab satetraxetan (Betalutin) is currently being evaluated in a clinical phase 2b trial for patients with follicular lymphoma (FL) and in a phase 1 trial for patients with diffuse large B-cell lymphoma (DLBCL). Herein we have investigated the effect of 177Lu-lilotomab satetraxetan in seven activated B-cell like (ABC) DLBCL cell lines. Although the radioimmunoconjugate showed anti-tumor activity, primary resistance was observed in a subset of cell lines. Thus, we set out to identify drugs able to overcome the resistance to 177Lu-lilotomab satetraxetan in two resistant ABC-DLBCL cell lines. We performed a viability-based screen combining 177Lu-lilotomab satetraxetan with the 384-compound Cambridge Cancer Compound Library. Drug combinations were scored using Bliss and Chou-Talalay algorithms. We identified and characterized the dual-specific CDK1/2 and AURA/B kinase inhibitor JNJ-7706621 as compound able to revert the resistance to RIT, alongside topoisomerase and histone deacetylases (HDAC) inhibitors.

12.
BMJ Evid Based Med ; 24(4): 149-154, 2019 08.
Article in English | MEDLINE | ID: mdl-31208984

ABSTRACT

Information mastery is an approach to applying the methods of evidence-based medicine to everyday practice. The aim of this research is to describe concepts identified by clinicians attending a 3-day course on applied evidence-based medicine that led to 'transformative learning', in which they experienced a deep, structural shift in the basic premises of thought, feelings and actions in their approach to making medical decisions. We used a qualitative approach to capture the lived experience of 12 current and 9 prior attendees of the 'information mastery' course through individual interviews, focus groups and observation. Data were thematically analysed and themes were reported. We found that current and previous attendees who seemed to undergo transformative learning identified eight concepts that constitute an information mastery approach to medical decision-making, which we grouped into two general themes. Some participants attending this course underwent transformative learning, resulting in an alternative decision-making process no longer relying on the anecdotes or guidance of others (what 'ought to work') and instead on incorporating patient-oriented outcomes based on the best evidence (what 'does work').


Subject(s)
Clinical Decision-Making , Evidence-Based Medicine/education , Adult , Clinical Decision-Making/methods , Female , Humans , Male , Middle Aged , Teaching
13.
Cell Cycle ; 18(8): 834-847, 2019 04.
Article in English | MEDLINE | ID: mdl-30943845

ABSTRACT

The Wee1 inhibitor MK1775 (AZD1775) is currently being tested in clinical trials for cancer treatment. Here, we show that the p53 target and CDK inhibitor p21 protects against MK1775-induced DNA damage during S-phase. Cancer and normal cells deficient for p21 (HCT116 p21-/-, RPE p21-/-, and U2OS transfected with p21 siRNA) showed higher induction of the DNA damage marker γH2AX in S-phase in response to MK1775 compared to the respective parental cells. Furthermore, upon MK1775 treatment the levels of phospho-DNA PKcs S2056 and phospho-RPA S4/S8 were higher in the p21 deficient cells, consistent with increased DNA breakage. Cell cycle analysis revealed that these effects were due to an S-phase function of p21, but MK1775-induced S-phase CDK activity was not altered as measured by CDK-dependent phosphorylations. In the p21 deficient cancer cells MK1775-induced cell death was also increased. Moreover, p21 deficiency sensitized to combined treatment of MK1775 and the CHK1-inhibitor AZD6772, and to the combination of MK1775 with ionizing radiation. These results show that p21 protects cancer cells against Wee1 inhibition and suggest that S-phase functions of p21 contribute to mediate such protection. As p21 can be epigenetically downregulated in human cancer, we propose that p21 levels may be considered during future applications of Wee1 inhibitors.


Subject(s)
Antineoplastic Agents/pharmacology , Cell Cycle Proteins/antagonists & inhibitors , Cyclin-Dependent Kinase Inhibitor p21/metabolism , DNA Damage/drug effects , Neoplasms/metabolism , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrazoles/pharmacology , Pyrimidinones/pharmacology , S Phase Cell Cycle Checkpoints/drug effects , Antineoplastic Agents/therapeutic use , Cell Survival/drug effects , Cell Survival/genetics , Cell Survival/radiation effects , Checkpoint Kinase 1/antagonists & inhibitors , Cyclin-Dependent Kinase Inhibitor p21/genetics , Cyclin-Dependent Kinases/antagonists & inhibitors , Cyclin-Dependent Kinases/metabolism , DNA Damage/genetics , HCT116 Cells , Humans , Neoplasms/drug therapy , Phosphorylation/drug effects , Pyrazoles/therapeutic use , Pyrimidinones/therapeutic use , RNA, Small Interfering/genetics , Transfection
14.
Methods Enzymol ; 619: 145-159, 2019.
Article in English | MEDLINE | ID: mdl-30910019

ABSTRACT

The 26S proteasome is a multisubunit ATP-dependent peptidase complex mediating most regulated protein degradation in eukaryotes. The proteasome undergoes several coordinated conformational changes during catalysis that activate it for substrate processing and functionally couple distinct enzymatic activities during substrate degradation. Understanding the impact of substrate interactions and individual ATP binding events on these conformational changes is currently a major bottleneck in the study of proteasome function. Here, we describe a simple biochemical reporter based on engineered disulfide crosslinking for measuring the conformational distribution of the Saccharomyces cerevisiae 26S proteasome. We demonstrate its use to investigate the impact of ATP analogs and proteasome inhibitors on proteasome conformational equilibria. This reporter allows simultaneous and rapid comparison of multiple treatments or conditions on the steady-state conformational distribution of the proteasome and can be readily extended to the study of other multisubunit complexes for which multiple conformational states are known at near-atomic resolution.


Subject(s)
Cross-Linking Reagents/chemistry , Disulfides/chemistry , Proteasome Endopeptidase Complex/chemistry , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae/chemistry , Adenosine Triphosphate/analogs & derivatives , Adenosine Triphosphate/pharmacology , Models, Molecular , Proteasome Inhibitors/chemistry , Proteasome Inhibitors/pharmacology , Protein Conformation/drug effects , Protein Subunits/chemistry , Saccharomyces cerevisiae Proteins/antagonists & inhibitors
15.
Cell Rep ; 26(2): 483-495.e5, 2019 01 08.
Article in English | MEDLINE | ID: mdl-30625330

ABSTRACT

The 26S proteasome is the central ATP-dependent protease in eukaryotes and is essential for organismal health. Proteasome assembly is mediated by several dedicated, evolutionarily conserved chaperone proteins. These chaperones associate transiently with assembly intermediates but are absent from mature proteasomes. Chaperone eviction upon completion of proteasome assembly is necessary for normal proteasome function, but how they are released remains unresolved. Here, we demonstrate that the Nas6 assembly chaperone, homolog of the human oncogene gankyrin, is evicted from nascent proteasomes during completion of assembly via a conformation-specific allosteric interaction of the Rpn5 subunit with the proteasomal ATPase ring. Subsequent ATP binding by the ATPase subunit Rpt3 promotes conformational remodeling of the ATPase ring that evicts Nas6 from the nascent proteasome. Our study demonstrates how assembly-coupled allosteric signals promote chaperone eviction and provides a framework for understanding the eviction of other chaperones from this biomedically important molecular machine.


Subject(s)
Allosteric Site , Proteasome Endopeptidase Complex/metabolism , Saccharomyces cerevisiae Proteins/metabolism , Adenosine Triphosphate/metabolism , Allosteric Regulation , Proteasome Endopeptidase Complex/chemistry , Protein Binding , Saccharomyces cerevisiae , Saccharomyces cerevisiae Proteins/chemistry
16.
Nucleic Acids Res ; 47(4): 1797-1813, 2019 02 28.
Article in English | MEDLINE | ID: mdl-30541148

ABSTRACT

Ataxia telangiectasia mutated and Rad3-related (ATR) kinase is a key factor activated by DNA damage and replication stress. An alternative pathway for ATR activation has been proposed to occur via stalled RNA polymerase II (RNAPII). However, how RNAPII might signal to activate ATR remains unknown. Here, we show that ATR signaling is increased after depletion of the RNAPII phosphatase PNUTS-PP1, which dephosphorylates RNAPII in its carboxy-terminal domain (CTD). High ATR signaling was observed in the absence and presence of ionizing radiation, replication stress and even in G1, but did not correlate with DNA damage or RPA chromatin loading. R-loops were enhanced, but overexpression of EGFP-RNaseH1 only slightly reduced ATR signaling after PNUTS depletion. However, CDC73, which interacted with RNAPII in a phospho-CTD dependent manner, was required for the high ATR signaling, R-loop formation and for activation of the endogenous G2 checkpoint after depletion of PNUTS. In addition, ATR, RNAPII and CDC73 co-immunoprecipitated. Our results suggest a novel pathway involving RNAPII, CDC73 and PNUTS-PP1 in ATR signaling and give new insight into the diverse functions of ATR.


Subject(s)
Ataxia Telangiectasia Mutated Proteins/genetics , RNA Polymerase II/genetics , Stress, Physiological/genetics , Tumor Suppressor Proteins/genetics , Animals , Chromatin/genetics , DNA Damage/radiation effects , DNA-Binding Proteins/genetics , Gene Expression Regulation/radiation effects , Green Fluorescent Proteins/genetics , Humans , Mice , Nuclear Proteins/genetics , Phosphorylation/radiation effects , RNA-Binding Proteins/genetics , Radiation, Ionizing , Receptors, Neuropeptide Y/genetics , Ribonuclease H/genetics , Signal Transduction/radiation effects , Stress, Physiological/radiation effects
17.
Cell Rep ; 24(5): 1301-1315.e5, 2018 07 31.
Article in English | MEDLINE | ID: mdl-30067984

ABSTRACT

The proteasome is the central protease for intracellular protein breakdown. Coordinated binding and hydrolysis of ATP by the six proteasomal ATPase subunits induces conformational changes that drive the unfolding and translocation of substrates into the proteolytic 20S core particle for degradation. Here, we combine genetic and biochemical approaches with cryo-electron microscopy and integrative modeling to dissect the relationship between individual nucleotide binding events and proteasome conformational dynamics. We demonstrate unique impacts of ATP binding by individual ATPases on the proteasome conformational distribution and report two conformational states of the proteasome suggestive of a rotary ATP hydrolysis mechanism. These structures, coupled with functional analyses, reveal key roles for the ATPases Rpt1 and Rpt6 in gating substrate entry into the core particle. This deepened knowledge of proteasome conformational dynamics reveals key elements of intersubunit communication within the proteasome and clarifies the regulation of substrate entry into the proteolytic chamber.


Subject(s)
Molecular Dynamics Simulation , Proteasome Endopeptidase Complex/chemistry , Adenosine Triphosphatases/chemistry , Adenosine Triphosphatases/metabolism , Adenosine Triphosphate/metabolism , Binding Sites , Proteasome Endopeptidase Complex/metabolism , Protein Binding , Saccharomyces cerevisiae , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae Proteins/metabolism
18.
Eur J Cancer ; 103: 356-387, 2018 11.
Article in English | MEDLINE | ID: mdl-30100160

ABSTRACT

INTRODUCTION: Europe contains 9% of the world population but has a 25% share of the global cancer burden. Up-to-date cancer statistics in Europe are key to cancer planning. Cancer incidence and mortality estimates for 25 major cancers are presented for the 40 countries in the four United Nations-defined areas of Europe and for Europe and the European Union (EU-28) for 2018. METHODS: Estimates of national incidence and mortality rates for 2018 were based on statistical models applied to the most recently published data, with predictions obtained from recent trends, where possible. The estimated rates in 2018 were applied to the 2018 population estimates to obtain the estimated numbers of new cancer cases and deaths in Europe in 2018. RESULTS: There were an estimated 3.91 million new cases of cancer (excluding non-melanoma skin cancer) and 1.93 million deaths from cancer in Europe in 2018. The most common cancer sites were cancers of the female breast (523,000 cases), followed by colorectal (500,000), lung (470,000) and prostate cancer (450,000). These four cancers represent half of the overall burden of cancer in Europe. The most common causes of death from cancer were cancers of the lung (388,000 deaths), colorectal (243,000), breast (138,000) and pancreatic cancer (128,000). In the EU-28, the estimated number of new cases of cancer was approximately 1.6 million in males and 1.4 million in females, with 790,000 men and 620,000 women dying from the disease in the same year. CONCLUSION: The present estimates of the cancer burden in Europe alongside a description of the profiles of common cancers at the national and regional level provide a basis for establishing priorities for cancer control actions across Europe. The estimates presented here are based on the recorded data from 145 population-based cancer registries in Europe. Their long established role in planning and evaluating national cancer plans on the continent should not be undervalued.


Subject(s)
Neoplasms/epidemiology , Neoplasms/mortality , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Europe , History, 21st Century , Humans , Incidence , Infant , Infant, Newborn , Male , Middle Aged , Young Adult
19.
J Contin Educ Health Prof ; 38(2): 102-109, 2018.
Article in English | MEDLINE | ID: mdl-29851715

ABSTRACT

INTRODUCTION: Continuing medical information courses have been criticized for not promoting behavior change among their participants. For behavior change to occur, participants often need to consciously reject previous ideas and transform their way of thinking. Transformational learning is a process that cultivates deep emotional responses and can lead to cognitive and behavioral change in learners, potentially facilitating rich learning experiences and expediting knowledge translation. We explored participants' experiences at a 2-day conference designed to support transformative learning as they encounter new concepts within Information Mastery, which challenge their previous frameworks around the topic of medical decision making. Using the lens of transformative learning theory, we asked: how does Information Mastery qualitatively promote perspective transformation and hence behavior change? METHODS: We used a hermeneutic phenomenologic approach to capture the lived experience of 12 current and nine previous attendees of the "Information Mastery" course through individual interviews, focus groups, and observation. Data were thematically analyzed. RESULTS: Both prevoius and current conference attendees described how the delivery of new concepts about medical decision making evoked strong emotional responses, facilitated personal transformation, and propelled expedited behavior change around epistemological, moral, and information management themes, resulting in a newfound sense of self-efficacy, confidence, and ownership in their ability to make medical decisions. DISCUSSION: When the topic area holds the potential to foster a qualitative reframing of learners' guiding paradigms and worldviews, attention should be paid to supporting learners' personalized meaning-making process through transformative learning opportunities to promote translation into practice.


Subject(s)
Decision Making , Evidence-Based Medicine/methods , Problem-Based Learning/methods , Education, Medical, Continuing/methods , Evidence-Based Medicine/standards , Focus Groups/methods , Humans , Problem-Based Learning/standards , Qualitative Research
20.
Sci Rep ; 8(1): 6880, 2018 05 02.
Article in English | MEDLINE | ID: mdl-29720710

ABSTRACT

Checkpoint kinases are important in cellular surveillance pathways that help cells to cope with DNA damage and protect their genomes. In cycling cells, DNA replication is one of the most sensitive processes and therefore all organisms carefully regulate replication initiation and progression. The checkpoint kinase ATR plays important roles both in response to DNA damage and replication stress, and ATR inhibitors are currently in clinical trials for cancer treatment. Therefore, it is important to understand the roles of ATR in detail. Here we show that the fission yeast homologue Rad3 and the human ATR regulate events also in G1 phase in an unperturbed cell cycle. Rad3Δ mutants or human cells exposed to ATR inhibitor in G1 enter S phase prematurely, which results in increased DNA damage. Furthermore, ATR inhibition in a single G1 reduces clonogenic survival, demonstrating that long-term effects of ATR inhibition during G1 are deleterious for the cell. Interestingly, ATR inhibition through G1 and S phase reduces survival in an additive manner, strongly arguing that different functions of ATR are targeted in the different cell-cycle phases. We propose that potential effects of ATR inhibitors in G1 should be considered when designing future treatment protocols with such inhibitors.


Subject(s)
Ataxia Telangiectasia Mutated Proteins/metabolism , Checkpoint Kinase 2/metabolism , G1 Phase , Schizosaccharomyces pombe Proteins/metabolism , Ataxia Telangiectasia Mutated Proteins/antagonists & inhibitors , Ataxia Telangiectasia Mutated Proteins/genetics , Cell Line , Cell Line, Tumor , Cell Survival/drug effects , Checkpoint Kinase 2/antagonists & inhibitors , Checkpoint Kinase 2/genetics , Humans , Protein Kinase Inhibitors/pharmacology , S Phase , Schizosaccharomyces , Schizosaccharomyces pombe Proteins/antagonists & inhibitors , Schizosaccharomyces pombe Proteins/genetics
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