2
|
Kiparaki M, Khan C, Folgado-Marco V, Chuen J, Moulos P, Baker NE. The transcription factor Xrp1 orchestrates both reduced translation and cell competition upon defective ribosome assembly or function. eLife 2022; 11:e71705. [PMID: 35179490 PMCID: PMC8933008 DOI: 10.7554/elife.71705] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 02/09/2022] [Indexed: 11/26/2022] Open
Abstract
Ribosomal Protein (Rp) gene haploinsufficiency affects translation rate, can lead to protein aggregation, and causes cell elimination by competition with wild type cells in mosaic tissues. We find that the modest changes in ribosomal subunit levels observed were insufficient for these effects, which all depended on the AT-hook, bZip domain protein Xrp1. Xrp1 reduced global translation through PERK-dependent phosphorylation of eIF2α. eIF2α phosphorylation was itself sufficient to enable cell competition of otherwise wild type cells, but through Xrp1 expression, not as the downstream effector of Xrp1. Unexpectedly, many other defects reducing ribosome biogenesis or function (depletion of TAF1B, eIF2, eIF4G, eIF6, eEF2, eEF1α1, or eIF5A), also increased eIF2α phosphorylation and enabled cell competition. This was also through the Xrp1 expression that was induced in these depletions. In the absence of Xrp1, translation differences between cells were not themselves sufficient to trigger cell competition. Xrp1 is shown here to be a sequence-specific transcription factor that regulates transposable elements as well as single-copy genes. Thus, Xrp1 is the master regulator that triggers multiple consequences of ribosomal stresses and is the key instigator of cell competition.
Collapse
Affiliation(s)
- Marianthi Kiparaki
- Department of Genetics, Albert Einstein College of MedicineThe BronxUnited States
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming”VariGreece
| | - Chaitali Khan
- Department of Genetics, Albert Einstein College of MedicineThe BronxUnited States
| | | | - Jacky Chuen
- Department of Genetics, Albert Einstein College of MedicineThe BronxUnited States
| | - Panagiotis Moulos
- Institute for Fundamental Biomedical Research, Biomedical Sciences Research Center "Alexander Fleming”VariGreece
| | - Nicholas E Baker
- Department of Genetics, Albert Einstein College of MedicineThe BronxUnited States
- Department of Developmental and Molecular Biology, Albert Einstein College of MedicineThe BronxUnited States
- Department of Opthalmology and Visual Sciences, Albert Einstein College of MedicineThe BronxUnited States
| |
Collapse
|
3
|
Ji Z, Chuen J, Kiparaki M, Baker N. Cell competition removes segmental aneuploid cells from Drosophila imaginal disc-derived tissues based on ribosomal protein gene dose. eLife 2021; 10:61172. [PMID: 33847264 PMCID: PMC8043752 DOI: 10.7554/elife.61172] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 03/08/2021] [Indexed: 12/22/2022] Open
Abstract
Aneuploidy causes birth defects and miscarriages, occurs in nearly all cancers and is a hallmark of aging. Individual aneuploid cells can be eliminated from developing tissues by unknown mechanisms. Cells with ribosomal protein (Rp) gene mutations are also eliminated, by cell competition with normal cells. Because Rp genes are spread across the genome, their copy number is a potential marker for aneuploidy. We found that elimination of imaginal disc cells with irradiation-induced genome damage often required cell competition genes. Segmentally aneuploid cells derived from targeted chromosome excisions were eliminated by the RpS12-Xrp1 cell competition pathway if they differed from neighboring cells in Rp gene dose, whereas cells with normal doses of the Rp and eIF2γ genes survived and differentiated adult tissues. Thus, cell competition, triggered by differences in Rp gene dose between cells, is a significant mechanism for the elimination of aneuploid somatic cells, likely to contribute to preventing cancer. Aneuploid cells emerge when cellular division goes awry and a cell ends up with the wrong number of chromosomes, the tiny genetic structures carrying the instructions that control life’s processes. Aneuploidy can lead to fatal conditions during development, and to cancer in an adult organism. A safety mechanism may exist that helps the body to detect and remove these cells. Yet, exactly this happens is still poorly understood: in particular, it is unclear how cells manage to ‘count’ their chromosomes. One way they could do so is through the ribosomes, the molecular ‘factories’ that create the building blocks required for life. In a cell, every chromosome carries genes that code for the proteins (known as Rps) forming ribosomes. Aneuploidy will alter the number of Rp genes, and in turn the amount and type of Rps the cell produces, so that ribosomes and the genes for Rps could act as a ‘readout’ of aneuploidy. Ji et al set out to test this theory in fruit flies. The first experiment used a genetic manipulation technique called site-specific recombination to remove parts of chromosomes from cells in the developing eye and wing. Cells which retained all their Rp genes survived, while those that were missing some usually died – but only when the surrounding cells were normal. In this situation, healthy cells eliminated their damaged neighbours through a process known as cell competition. A second experiment, using radiation as an alternative method of damaging chromosomes, also gave similar results. The work by Ji et al. reveals how the body can detect and eliminate aneuploid cells, potentially before they can cause harm. If the same mechanism applies in humans, boosting cell competition may, one day, helps to combat diseases like cancer.
Collapse
Affiliation(s)
- Zhejun Ji
- Department of Genetics, Albert Einstein College of Medicine, Bronx, United States
| | - Jacky Chuen
- Department of Genetics, Albert Einstein College of Medicine, Bronx, United States
| | - Marianthi Kiparaki
- Department of Genetics, Albert Einstein College of Medicine, Bronx, United States
| | - Nicholas Baker
- Department of Genetics, Albert Einstein College of Medicine, Bronx, United States
| |
Collapse
|
5
|
Das A, Coles-Black J, Pham T, Rajkomar AKS, Lawrentschuk N, Chuen J, Warrier S. Fully robotic retroperitoneal lymph node dissection - a fusion of technologies - a video vignette. Colorectal Dis 2020; 22:354. [PMID: 31698539 DOI: 10.1111/codi.14900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 10/08/2019] [Indexed: 02/08/2023]
Affiliation(s)
- A Das
- Department of Surgical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - J Coles-Black
- Department of Surgery, Austin Health, University of Melbourne, Melbourne, Victoria, Australia.,Austin Health 3D Medical Printing Laboratory, Melbourne, Victoria, Australia
| | - T Pham
- Department of Surgical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | | | - N Lawrentschuk
- Department of Surgical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.,Department of Surgery, Austin Health, University of Melbourne, Melbourne, Victoria, Australia.,Olivia Newton-John Cancer Research Institute, Melbourne, Victoria, Australia
| | - J Chuen
- Department of Surgery, Austin Health, University of Melbourne, Melbourne, Victoria, Australia.,Austin Health 3D Medical Printing Laboratory, Melbourne, Victoria, Australia
| | - S Warrier
- Department of Surgical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| |
Collapse
|
8
|
Raine D, Begg G, Moore J, Taylor E, Buck R, Honarbakhsh S, Yew Ding W, Redfearn D, Opel A, Opel A, Thomas D, Prakash K, Thomas D, Khokhar A, Honarbakhsh S, Tairova S, Getman N, McAloon C, Honarbakhsh S, Shah M, Al-Lawati K, Al-Lawati K, Ensam B, Collins G, Akbar S, Merghani A, Furniss G, Yones E, Vijayashankar SS, Vijayashankar SS, Shariat H, Moss A, Yeoh A, Sadiq A, Taylor R, Edwards T, Nizam ud Din K, Langley P, Shepherd E, Murray S, Lord S, Bourke J, Plein S, Lip G, Tayebjee MH, Owen N, White S, O'Neill M, Hughes L, Carroll S, Moss-Morris R, Baker V, Kirkby C, Patel K, Robinson G, Antoniou S, Richmond L, Ullah W, Hunter R, Finlay M, Earley M, Whitbread M, Schilling R, Cooper R, Modi S, Somani R, Ng A, Hobson N, Caldwell J, Hadjivassilev S, Ang R, Finlay M, Dhinoja M, Earley M, Sporton S, Schilling R, Hunter R, Hadjivassilev S, Earley M, Lambiase P, Turley A, Child N, Linker N, Owens W, James S, Milner J, Tayebjee M, Sibley J, Griffiths A, Meredith T, Basher Y, Betts T, Rajappan K, Lambiase P, Lowe M, Hunter R, Schilling R, Finlay M, Rakhimbaeva G, Akramova N, Getman T, Hamborg T, O'Hare J, Randeva H, Osman F, Srinivasan N, Kirkby C, Firman E, Tobin L, Murphy C, Lowe M, Hunter R, Finlay M, Schilling R, Lambiase P, Mohan P, Salahia G, Lim H, Lim HS, Batchvarov V, Brennan P, Cox A, Muir A, Behr E, Hamill S, Laventure C, Newell S, Gordon B, Bashir K, Chuen J, Foster W, Yusuf S, Osman F, Hayat S, Panagopoulos D, Davies E, Tomlinson D, Haywood G, Mullan J, Kelland N, Horwood A, Connell N, Odams S, Maloney J, Shetty A, Kyriacou A, Sahu J, Lee J, Uzun O, Wong A, Ashtekar S, Uzun O, Wong A, Ashtekar S, Hashemi J, Gazor S, Redfearn D, Song A, Jenkins J, Glancy J, Wilson D, Sammut E, Diab I, Cripps T, Gill A, Abbas S, Enye J, Wahab A, Elshafie S, Ling K, Carey P, Chatterjee D, Timbrell S, Tufail W, Why H, Martos R, Thornley A, James S, Turley A, Bates M, Linker N, Hassan E, Quick J, Cowell R, Ho E. POSTERS (1)59MULTIPOLAR CONTACT MAPPING GUIDED ABLATION OF TEMPORALLY STABLE HIGH FREQUENCY AND COMPLEX FRACTIONATED ATRIAL ELECTROGRAM SITES IN PATIENTS WITH PERSISTENT ATRIAL FIBRILLATION60INTRA-CARDIAC AND PERIPHERAL LEVELS OF BIOCHEMICAL MARKERS OF FIBROSES IN PATIENTS UNDERGOING CATHETER ABLATION FOR ATRIAL FIBRILATION61THE DON'T WAIT TO ANTICOAGULATE PROJECT (DWAC) BY THE WEST OF ENGLAND ACADEMIC HEALTH SCIENCE NETWORK (AHSN) OPTIMISES STROKE PREVENTION FOR PATIENTS WITH ATRIAL FIBRILLATION (AF) WITHIN PRIMARY CARE IN LINE WITH NICE CG180 IN THE WEST OF ENGLAND62ILLNESS AND TREATMENT REPRESENTATIONS, COPING AND DISTRESS: VICIOUS CYCLES OF EVERYDAY EXPERIENCES IN PATIENTS WITH PERSISTENT ATRIAL FIBRILLATION63THE NEEDS OF THE ADOLESCENT LIVING WITH AN INHERITED CARDIAC CONDITION: THE PATIENTS' PERSPECTIVE64SAFETY AND EFFICACY OF PARAMEDIC TREATMENT OF REGULAR SUPRAVENTRICULAR TACHYCARDIA (PARA-SVT)65NATURAL PROGRESSION OF QRS DURATION FOLLOWING IMPLATABLE CARDIOVERTER DEFIBRILLATORS (ICD) - IMPLANTATION66COMPARISON OF EFFICACY OF VOLTAGE DIRECTED CAVOTRICUSPID ISTHMUS ABLATION USING MINI VS CONVENTIONAL ELETRODES67CRYOBALLOON ABLATION (CRYO) FOR ATRIAL FIBRILLATION (AF) CANNOT BE GUIDED BY TEMPERATURE END-POINTS ALONE68MODERATOR BAND ECTOPY UNMASKED BY ADENOSINE AS A CAUSE OF ECTOPIC TRIGGERED IDIOPATHIC VF69EARLY CLINICAL EXPERIENCE WITH TARGETED SITE SELECTION FOR THE WiCS-LV ELECTRODE FOR CRT70DOES VECTOR MAPPING PRIOR TO IMPLANTABLE LOOP RECORDER INSERTION IMPROVE THE DETECTION OF ARRHYTHMIA?71THE ROLE OF SPECKLE TRACKING STRAIN IMAGING IN ASSESSING LEFT VENTRICULAR RESPONSE TO CARDIAC RESYNCHRONISATION THERAPY IN RESPONDERS AND NON-RESPONDERS72EVALUATING PATIENTS' EXPERIENCE AND SATISFACTION OF THE ATRIAL FIBRILLATION ABLATION PROCEDURE: A RETROSPECTIVE ANALYSIS73TROUBLESHOOTING LV LEAD IMPLANTATION - NOVEL “UNIRAIL TECHNIQUE”74SUBCLINICAL ATHEROSCELEROSIS AND COGNITIVE IMPAIRMENT75EFFECT OF LOZARTANE ON DEVELOPMENT OF THE ELECTRICAL INSTABILITY OF THE MYOCARDIUM76THE INTERPLAY BETWEEN BODY COMPOSITION AND LEFT VENTRICULAR REMODELLING IN CARDIAC RESYNCHRONISATION THERAPY77FAMILY SCREENING IN IDIOPATHIC VENTRICULAR FIBRILLATION78MANAGEMENT OF ATRIAL FIBRILLATION IN A LARGE TEACHING HOSPITAL79THE EFFECT OF LEFT VENTRICULAR LEAD POSITION ON SURVIVAL IN PATIENTS WITH BINVENTRICULAR PACEMAKRS/DEFIBRILLATORS80ACUTE DEVICE IMPLANT-RELATED COMPLICATIONS DO NOT INCREASE LATE MORTALITY81ABORTED CARIDAC ARREST AS THE SENTINEL PRESENTATION IN A COHORT OF PATIENTS WITH THE CONCEALED BRUGADA PHENOTYPE82POST-CARDIAC DEVICE IMPLANTATION MOBILISATION ADVICE: A NATIONAL SURVEY83DO RISK SCORES DEVELOPED TO PROTECT ONE-YEAR MORTALITY ACTUALLY HELP IN ACCURATELY SELECTING PATIENTS RECEIVING PRIMARY PREVENTION ICD?84ATRIAL TACHYCARDIA ARISING FROM THE NON-CORONARY AORTIC CUSP85THE EFFECT OF DIFFERENT ATRIAL FIBRILLATION ABLATION STRATEGIES ON SURFACE ECG P WAVE DURATION86PRESCRIBING DRONEDARONE: HOW IS IT DONE ACROSS THE UK AND IS IT SAFE?87A CASE OF WIDE COMPLEX TACHYCARDIA88TRANSITION TO DEDICATED DAY CASE DEVICES - SAFETY AND EFFICACY IN A LARGE VOLUME CENTRE89SEQUENTIAL REGIONAL DOMINANT FREQUENCY MAPPING DURING ATRIAL FIBRILLATION: A NOVEL TEQUNIQUE90ELECTIVE CARDIOVERSION ENERGY PROTOCOLS: A RETROSPECTIVE COMPARISON OF ESCALATION STRATEGIES91THE INCIDENCE OF CLINCALLY RELEVANT HAEMATOMAS WITH PERIOPERATIVE USE OF NEWER P2Y12 INHIBITORS AND INTERRUPTED NOAC THERAPY IN CARDIAC IMPLANTABLE ELECTRONIC DEVICE INSERTION92AN AUDIT OF THE OUTCOMES FOR CHEMICAL AND DIRECT CURRENT CARDIOVERSION FOR ATRIAL FIBRILLATION AT OUR DGH OVER A 3 YEAR DURATION93REAL LIFE ACUTE MANAGEMET OF HAEMODYNAMICALLY TOLERATED MONOMORPHIC VENTRICULAR TACHYCARDIA. ARE WE MAKING EVIDENCE BASED ON DECISIONS?94A SERVICE EVALUATION TO ASSESS THE EFFICACY AND SAFETY OF NOVEL ORAL ANTICOAGULANTS VERSUS WARFARIN FOR ELECTIVE CARDIVERSION IN PATIENTS WITH NON VALVULAR AF IN A NURSE LED CARDIOVERSION SERVICE95PICK UP RATE OF IMPLANTED LOOP RECORDER AT A DISTRICT HOSPITAL. Europace 2016. [DOI: 10.1093/europace/euw273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
12
|
Mourad WA, Vallieres E, Chuen J, Alrobaish A. Cell kinetics analysis of surgically resected non-small cell carcinoma of the lung using the AgNOR silver stain. Ann Saudi Med 1997; 17:161-6. [PMID: 17377422 DOI: 10.5144/0256-4947.1997.161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cell kinetics analysis of lung carcinoma using DNA flow cytometry has shown a significant correlation with the biological behavior of these neoplasms. Ploidy has shown a more significant association with aggressive behavior. The method may however not be available in all centers. Two counts of the AgNOR silver stain have been correlated with ploidy and proliferative activity (PA). The first count, which is the mean number of AgNOR granules (mAgNOR), correlates with ploidy. The second count is the percentage of cells with > 5 AgNORs/nucleus (pAgNOR), reflects PA. We performed the AgNOR silver stain using the two above-mentioned counts in 41 cases of surgically resected nonâsmall cell carcinoma of the lung. The cases included 14 adenocarcinomas, 24 squamous cell carcinomas, and three undifferentiated nonâsmall cell carcinomas. Follow-up data were available on 36 of the patients, ranging from 10 to 31 months (median 18 months). Thirteen of these patients (36%) developed progressive disease. Adenocarcinomas showed mAgNOR counts suggestive of aneuploidy (> 2.4) in nine of the 14 patients (64%) and 16 of the 24 squamous carcinomas (66%). The adenocarcinomas showed high pAgNOR counts (> 8%) in eight of the 14 cases (57%), in contrast to 15 of the 24 squamous carcinomas (62%). The AgNOR counts did not show any statistically significant correlation with tumor type, grade or stage of disease. The mAgNOR counts were aneuploid in all 13 progressive cases and in only 10 of the 23 stable cases (43%)(P=0.001). The pAgNOR counts were high in 12 of the 13 cases that progressed (92%), in contrast to 10 of the 23 stable cases (43%)(P=0.01). There is no significant evidence that squamous carcinoma of the lung may have a higher incidence of aneuploidy and high PA than adenocarcinoma. Our data also confirm previous data showing that aneuploid lung carcinomas have more aggressive behavior than diploid ones. This study also indicates that, despite the short-term follow-up data, the use of the AgNOR silver stain for cell kinetics analysis of nonâsmall cell carcinoma of the lung may potentially provide useful predictive information on the biologic behavior of lung carcinoma. Long-term follow-up may provide more significant information.
Collapse
Affiliation(s)
- W A Mourad
- Departments of Pathology, Surgery and Medicine, University of Alberta Hospitals, Edmonton, Alberta, Canada
| | | | | | | |
Collapse
|