Erratum: iTAG an optimized IMiD-induced degron for targeted protein degradation in human and murine cells.

[This corrects the article DOI: 10.1016/j.isci.2023.107059.].

Time to Look for Ergonomically Viable Designs of Radiation Protection Aprons and Thyroid Shields in Orthopedic Surgery: A Survey of 416 Orthopedic Surgeons.

Introduction The advent of minimally invasive surgery has increased the use of C-arm among orthopedic surgeons. Their views on the ergonomicity of radiation protection aprons and thyroid shields need elucidation. To investigate, we deliberated a question-based survey. The primary aim of the survey was to find out the percentage of those not using these devices, the prevalence of back pain, and its relationship with the type of radiation protection aprons. Materials and methods This was a cross-sectional survey. A five-section Google Forms survey (Google, Inc., Mountain View, CA) was filled out, and responses from 416 orthopedic surgeons were included. Analysis was carried out using Statistical Package for the Social Sciences (SPSS) version 14.0 (SPSS Inc., Chicago, IL). Results Of the total number of orthopedic surgeons, 36.8% felt that apart from radiation exposure, wearing a radiation protection apron was the biggest problem in C-arm usage. Furthermore, 20.4% wore thyroid shields the majority of the time. The 31-40 years age group was the most comfortable wearing these devices, wore them more often, and suffered more often from back pain (all p<0.01). Conclusion The study concluded that the majority of orthopedic surgeons were not comfortable with the current designs of radiation protection aprons and thyroid shields. Thyroid shields are worn less than aprons. Lead apron weight and thyroid shield ergonomicity were the number one reason for being bare-bodied. Among those who regularly wore aprons, a large proportion suffered from back pain.

A Degron Blocking Strategy Towards Improved CRL4CRBN Recruiting PROTAC Selectivity.

Small molecules inducing protein degradation are important pharmacological tools to interrogate complex biology and are rapidly translating into clinical agents. However, to fully realise the potential of these molecules, selectivity remains a limiting challenge. Herein, we addressed the issue of selectivity in the design of CRL4CRBN recruiting PROteolysis TArgeting Chimeras (PROTACs). Thalidomide derivatives used to generate CRL4CRBN recruiting PROTACs have well described intrinsic monovalent degradation profiles by inducing the recruitment of neo-substrates, such as GSPT1, Ikaros and Aiolos. We leveraged structural insights from known CRL4CRBN neo-substrates to attenuate and indeed remove this monovalent degradation function in well-known CRL4CRBN molecular glues degraders, namely CC-885 and Pomalidomide. We then applied these design principles on a previously published BRD9 PROTAC (dBRD9-A) and generated an analogue with improved selectivity profile. Finally, we implemented a computational modelling pipeline to show that our degron blocking design does not impact PROTAC-induced ternary complex formation. We believe that the tools and principles presented in this work will be valuable to support the development of targeted protein degradation.

iTAG an optimized IMiD-induced degron for targeted protein degradation in human and murine cells.

To address the limitation associated with degron based systems, we have developed iTAG, a synthetic tag based on IMiDs/CELMoDs mechanism of action that improves and addresses the limitations of both PROTAC and previous IMiDs/CeLMoDs based tags. Using structural and sequence analysis, we systematically explored native and chimeric degron containing domains (DCDs) and evaluated their ability to induce degradation. We identified the optimal chimeric iTAG(DCD23 60aa) that elicits robust degradation of targets across cell types and subcellular localizations without exhibiting the well documented "hook effect" of PROTAC-based systems. We showed that iTAG can also induce target degradation by murine CRBN and enabled the exploration of natural neo-substrates that can be degraded by murine CRBN. Hence, the iTAG system constitutes a versatile tool to degrade targets across the human and murine proteome.

SimPLIT: Simplified Sample Preparation for Large-Scale Isobaric Tagging Proteomics.

Large scale proteomic profiling of cell lines can reveal molecular signatures attributed to variable genotypes or induced perturbations, enabling proteogenomic associations and elucidation of pharmacological mechanisms of action. Although isobaric labeling has increased the throughput of proteomic analysis, the commonly used sample preparation workflows often require time-consuming steps and costly consumables, limiting their suitability for large scale studies. Here, we present a simplified and cost-effective one-pot reaction workflow in a 96-well plate format (SimPLIT) that minimizes processing steps and demonstrates improved reproducibility compared to alternative approaches. The workflow is based on a sodium deoxycholate lysis buffer and a single detergent cleanup step after peptide labeling, followed by quick off-line fractionation and MS2 analysis. We showcase the applicability of the workflow in a panel of colorectal cancer cell lines and by performing target discovery for a set of molecular glue degraders in different cell lines, in a 96-sample assay. Using this workflow, we report frequently dysregulated proteins in colorectal cancer cells and uncover cell-dependent protein degradation profiles of seven cereblon E3 ligase modulators (CRL4CRBN). Overall, SimPLIT is a robust method that can be easily implemented in any proteomics laboratory for medium-to-large scale TMT-based studies for deep profiling of cell lines.

Signs and lines in lung ultrasound.

Point-of-care ultrasound has become firmly established in acute and critical care settings, and is now increasingly being used as an important tool in the assessment of the lungs. In this article, we briefly describe the technique of lung ultrasound and the various lines and signs commonly encountered during sonography of the lung, namely the normally visualised A- and T-lines and the bat sign, sliding sign (power slide sign on colour Doppler), sea-shore sign, curtain sign, and the lung pulse. We have also described signs seen in various pathological conditions like B-lines seen in cases of increased lung density; the quad sign, sinusoid sign, thoracic spine sign, plankton sign and the jelly fish sign seen in pleural effusion; the stratosphere sign and the lung point sign seen in pneumothorax; the shred/fractal sign and tissue-like sign in consolidation, and the double lung point sign seen in transient tachypnoea of the newborn. With adequate and appropriate training, lung ultrasound can be effectively utilised as a point-of-care investigation.

Investigating the phosphinic acid tripeptide mimetic DG013A as a tool compound inhibitor of the M1-aminopeptidase ERAP1.

ERAP1 is a zinc-dependent M1-aminopeptidase that trims lipophilic amino acids from the N-terminus of peptides. Owing to its importance in the processing of antigens and regulation of the adaptive immune response, dysregulation of the highly polymorphic ERAP1 has been implicated in autoimmune disease and cancer. To test this hypothesis and establish the role of ERAP1 in these disease areas, high affinity, cell permeable and selective chemical probes are essential. DG013A 1, is a phosphinic acid tripeptide mimetic inhibitor with reported low nanomolar affinity for ERAP1. However, this chemotype is a privileged structure for binding to various metal-dependent peptidases and contains a highly charged phosphinic acid moiety, so it was unclear whether it would display the high selectivity and passive permeability required for a chemical probe. Therefore, we designed a new stereoselective route to synthesize a library of DG013A 1 analogues to determine the suitability of this compound as a cellular chemical probe to validate ERAP1 as a drug discovery target.

Phenotypic screening with target identification and validation in the discovery and development of E3 ligase modulators.

The use of phenotypic screening was central to the discovery and development of novel thalidomide analogs, the IMiDs (immunomodulatory drugs) agents. With the discovery that these agents bind the E3 ligase, CRL4CRBN, and alter its substrate specificity, there has been a great deal of endeavor to discover other small molecules that can modulate alternative E3 ligases. Furthermore, the chemical properties necessary for drug discovery and the rules by which neo-substrates are selected for degradation are being defined in the context of phenotypic alterations in specific cellular systems. This review gives a detailed summary of these recent advances and the methodologies being exploited to understand the mechanism of action of emerging protein degradation therapies.

Clinico-Radiological Evaluation of Modified Stoppa Approach in Treatment of Acetabulum Fractures.

Background The aim of our study was to evaluate the efficacy of Modified Stoppa approach for surgical treatment of acetabulum fractures by analyzing clinical and radiological outcomes. Also, we assess intraoperative and postoperative complications of fracture treated by using Modified Stoppa approach. Objectives To evaluate clinical outcomes of Modified Stoppa approach by using Merle d'Aubigne hip score. To evaluate the radiological reduction quality of Modified Stoppa approach by using the criteria of Matta, and to assess complications of Modified Stoppa approach.  Method Thirty-two patients participated in this study (mean age 40 years; range 18-60 years) and the male to female ratio was 4:1, patients who underwent surgical intervention for acetabular fracture by using Modified Stoppa approach from Oct 2017 to April 2019 were included. Out of 32 patients, two were lost in follow up, leaving 30 of 32 patients for clinico-radiological analysis. We classified the fracture pattern according to Judet and Letournel classification based on preoperative X-ray AP view, Judet View, and 3D-CT pelvis. Operative time, blood loss, reduction quality, and perioperative complications were assessed in each patient. Clinical outcomes were assessed by Merle d'Aubigne hip score and radiological outcomes by criteria of Matta.  Results Out of 30 acetabulum fractures in 30 patients, three (10%) were categorized as anterior column fracture, one (3.3%) as transverse with posterior wall, one (3.33%) as T-type, six (20%) as anterior column with posterior hemi-transverse and 19 (63.33%) as both column fractures. In our study, most patients have trauma due to road traffic accident (RTA) in 25 (83.3%) and fall from stairs in three (10%) patients. Timing of surgery after trauma was average 5.83 days (range three to 15 days), Mean surgical time determined to be 214.66 min (range 150-350 min) and mean intraoperative loss 683.33 ml (range 230-1250 ml). Clinical outcomes by Merle d'Aubigne hip score was excellent in 13 (43.33%), good in 15 (50%), fair in two (6.66%) patients whereas poor results in 0 (0%) patient (p=0.001). Quality of reduction by Matta criteria was found to be an anatomical reduction in 26 (86.6%), imperfect reduction in three (10%), and poor reduction in one patient (3.33%) (p<0.001). Radiological grading by Matta criteria was excellent in 24 (80%), good in five (16.66%), and fair in one (3.33%) patient, and no patients met criteria for poor results (p<0.001). In operative complications one patient developed an external iliac vein injury which was repaired by a vascular surgeon, one patient had a superficial infection for which debridement, regular dressing, and IV antibiotics given and resolve in one month, obturator nerve injury in one patient which was resolve in five to six months, lateral femoral cutaneous nerve injury in one patient which resolved within three months and one patient urinary bladder injury which was repaired by a general surgeon.  Conclusion Our experience with Modified Stoppa approach for surgical treatment of acetabulum fracture in 30 patients is excellent and effective for better visualization to anterior column, quadrilateral plate, and up to sacroiliac joint. This approach provides better visibility of the fracture site which allows for good to an excellent reduction of fracture and fixation. Although Stoppa approach is cosmetic surgery in terms of scar size, there is less complication rate than the ilioinguinal approach.

Quizartinib-resistant FLT3-ITD acute myeloid leukemia cells are sensitive to the FLT3-Aurora kinase inhibitor CCT241736.

Internal tandem duplication of FLT3 (FLT3-ITD) is one of the most common somatic mutations in acute myeloid leukemia (AML); it causes constitutive activation of FLT3 kinase and is associated with high relapse rates and poor survival. Small-molecule inhibition of FLT3 represents an attractive therapeutic strategy for this subtype of AML, although resistance from secondary FLT3 tyrosine kinase domain (FLT3-TKD) mutations is an emerging clinical problem. CCT241736 is an orally bioavailable, selective, and potent dual inhibitor of FLT3 and Aurora kinases. FLT3-ITD+ cells with secondary FLT3-TKD mutations have high in vitro relative resistance to the FLT3 inhibitors quizartinib and sorafenib, but not to CCT241736. The mechanism of action of CCT241736 results in significant in vivo efficacy, with inhibition of tumor growth observed in efficacy studies in FLT3-ITD and FLT3-ITD-TKD human tumor xenograft models. The efficacy of CCT241736 was also confirmed in primary samples from AML patients, including those with quizartinib-resistant disease, which induces apoptosis through inhibition of both FLT3 and Aurora kinases. The unique combination of CCT241736 properties based on robust potency, dual selectivity, and significant in vivo activity indicate that CCT241736 is a bona fide clinical drug candidate for FLT3-ITD and TKD AML patients with resistance to current drugs.

Sternoclavicular tuberculosis: an atypical imitator of refractory shoulder pain.

INTRODUCTION: Sternoclavicular joint tuberculosis is rare and has been presented in literature with few sporadic case reports or small case series. Rarity of the condition, nonspecific symptoms, difficulty to visualise the area on X-rays, and minimal clinical signs make diagnosis of sternoclavicular tuberculosis extremely difficult. Delay in diagnosis is therefore the common feature of all presented reports in literature. We here present our experience of treating 19 cases of sternoclavicular tuberculosis at our centre. MATERIALS AND METHOD: This is an observational study from 2010 to 2017 in a tertiary care referral hospital. All patients with clinical tenderness of sternoclavicular joint and shoulder joint pain of over three week duration were subjected to MRI. Patients who showed radiological lesions (radiography/MRI) were subjected to core biopsy under image guidance. A total of 26 patients had biopsy confirmed sternoclavicular tuberculosis (TB) during this period. RESULTS: All patients had improvement in shoulder function after treatment completion. Mean CSS pre-treatment was 29 which improved to mean of 8 after 18 months of ATT. Eight patients had excellent results, seven good, three fair, and one patient poor result. High initial ESR, late commencement of ATT from initial symptoms, and surgery of the involved joint were considered poor prognostic factors. DISCUSSION: Sternoclavicular tuberculosis is a rare disease with controversial etiology. Both haematogenous spread through suprascapular artery and contiguous spread through latent disease in apical lungs has been postulated. Delay in diagnosis is common to most reports in literature. Early MRI is useful in diagnosis of the lesion. The treatment for sternoclavicular joint in literature is controversial with proponents of both surgery and conservative management. CONCLUSION: Primary sternoclavicular tuberculosis is rare condition and requires a high index of suspicion for an early diagnosis. A focused sternoclavicular MRI and early biopsy may help in timely diagnosis. Early commencement of ATT has overall good clinical and functional results.

Experience of valgus osteotomy for neglected and failed osteosynthesis in fractures neck of femur.

PURPOSE: There is vast literature supporting valgus osteotomy in fracture neck of femur. However, little or no distinction has ever been made to evaluate the success of the procedure in these two different scenarios-non-unions due to failed osteosynthesis and neglected fractures neck of femur. The aim of our study was to compare the results of valgus osteotomy in neglected neck femur fractures and non-union fractures of neck of femur. METHODS: This is a single tertiary centre-based retrospective study. The records of all patients aged less than 45 years who underwent valgus osteotomy for neck of femur fractures from 2012 to 2017 were evaluated. Patients with fracture neck of femur of over one month's duration, where no previous surgical intervention was undertaken were placed in neglected fracture group. Patients with failed primary osteosynthesis surgery, either cannulated cancellous screw or dynamic hip screw, were placed in fixation failure group. There were 23 patients in neglected group and 17 patients in fixation failure group. Demographical details, fracture patterns, and preoperative radiograph, surgery time, blood loss, post-operative complications, union time, and non-unions were studied in both groups. RESULTS: Osteotomy site united in mean time of 11 weeks in fixation failure group and 11.3 weeks in neglected group (p = .434). Time to radiological union of fracture was 16 weeks (12-23 weeks) for neglected fracture group compared to 25 weeks (20-32 weeks) for fixation failure group which was statistically significant (p = .02). Seven out of 17 fractures did not unite in fixation failure group compared to one non-union out of 23 patients in neglected group. (p = .004) There were two loss of fixation with implant failure in fixation failure group compared to none in neglected group (p = .174). Neither of the groups had any surgical site infection. CONCLUSION: Valgus osteotomy results in excellent union rates for neglected fractures of neck of femur. However, the union rates of valgus osteotomy are lower in neck femur fractures with failed implants compared to neglected fractures and the procedure should be cautiously used in such circumstances.

A diagnostic dilema in benign lytic lesions of clavicle - our experience of 37 patients.

INTRODUCTION: The studies on benign lytic lesion of clavicle are sparse. Asymptomatic nature of lesions, rare occurrence, the difficulty in interpretation of the X-rays because of the surrounding structures and striking similarities in various lesions further make the diagnosis of such atraumatic lytic lesions difficult. MATERIAL AND METHODS: Prompted by the rarity of lesion and scarcity of data regarding presentation and management, we performed a prospective study of benign lytic lesions of clavicle. The results of the lesions are categorised in infective, metabolic and neoplastic conditions. RESULTS: Infective lesions were most common cause of symptomatic painful benign lytic lesions. Metabolic lesions, like rickets, were the most common cause of painless swelling in clavicle. Neoplastic conditions although rare were an important differential. CONCLUSION: It is important to differentiate and diagnose lytic lesions of clavicle. Early MRI and Biopsy of the lesion helps in preventing an undue delay in diagnosis. Most lesions when diagnosed in time have excellent results.

A critical evaluation of the approaches to targeted protein degradation for drug discovery.

There is a great deal of excitement around the concept of targeting proteins for degradation as an alternative to conventional inhibitory small molecules and antibodies. Protein degradation can be undertaken by bifunctional molecules that bind the target for ubiquitin mediated degradation by complexing them with Cereblon (CRBN), von Hippel-Lindau or other E-3 ligases. Alternatively, E-3 ligase receptors such as CRBN or DCAF15 can also be used as a 'template' to bind IMiD or sulphonamide like compounds to degrade multiple context specific proteins by the selected E-3 ligases. The 'template approach' results in the degradation of neo-substrates, some of which would be difficult to drug using conventional approaches. The chemical properties necessary for drug discovery, the rules by which neo-substrates are selected by E-3 ligase receptors and defining the optimal components of the ubiquitin proteasome for protein degradation are still to be fully elucidate. Theis review will aim to critically evaluate the different approaches and principles emerging for targted protein degradation.

Challenges to curing primary brain tumours.

Despite decades of research, brain tumours remain among the deadliest of all forms of cancer. The ability of these tumours to resist almost all conventional and novel treatments relates, in part, to the unique cell-intrinsic and microenvironmental properties of neural tissues. In an attempt to encourage progress in our understanding and ability to successfully treat patients with brain tumours, Cancer Research UK convened an international panel of clinicians and laboratory-based scientists to identify challenges that must be overcome if we are to cure all patients with a brain tumour. The seven key challenges summarized in this Position Paper are intended to serve as foci for future research and investment.

Primary hydatidosis of distal femur masquerading malignancy -A rare case.

Hydatidosis is relatively uncommon entity and it rarely affects bone and joints. A rare case of primary hydatidosis (Echhinococcus granulosus infection) involving the distal femur and the knee joint in a 53 years old female is reported here. This presented as a pathological supracondylar fracture of femur. On establishment of a clinical diagnosis she was treated preoperatively with Albendazole 600 mg, daily for 3 cycles each of 21 days with a gap of 1 weeks between cycles. Two stage surgery was carried out, the first being a meticulous debridement and second a total knee replacement with cemented tumor mega-prosthesis. Postoperatively the wound healed completely without any evidence of infection and albendazole therapy was continued for three months following surgery. During the follow-up period of two and a half year, no recurrence of hydatidosis was noticed.

A First-in-Human Study of Novel Cereblon Modulator Avadomide (CC-122) in Advanced Malignancies.

PURPOSE: Avadomide is a novel, small-molecule therapeutic agent that modulates cereblon E3 ligase activity and exhibits potent antitumor and immunomodulatory activities. This first-in-human phase I study (NCT01421524) evaluated the safety and clinical activity of avadomide in patients with advanced solid tumors, non-Hodgkin lymphoma (NHL), and multiple myeloma. PATIENTS AND METHODS: Thirty-four patients were treated with avadomide in 7 dose-escalation cohorts using a 3 + 3 design (0.5-3.5 mg, 28-day continuous dosing cycles). The primary objectives were to determine the dose-limiting toxicity (DLT), nontolerated dose (NTD), maximum tolerated dose (MTD), recommended phase II dose, and pharmacokinetics of avadomide. The secondary objective was to determine preliminary avadomide efficacy. Exploratory objectives included evaluation of pharmacodynamic effects of avadomide. RESULTS: DLTs were reported in 2 patients, and grade ≥3 treatment-emergent adverse events (TEAEs) occurred in 14 patients (41%). The most common TEAEs (≥15%) were fatigue, neutropenia, and diarrhea. The NTD and MTD were 3.5 and 3.0 mg, respectively. Of 5 patients with NHL, 1 achieved a complete response, and 2 had partial responses. Although no objective responses were observed in patients with solid tumors, 5 of 6 patients with brain cancer experienced nonprogression of ≥6 months. A dose-dependent relationship between Aiolos degradation in peripheral B and T cells occurred within 5 hours of the first dose of avadomide administered, starting at 0.5 mg. CONCLUSIONS: Avadomide monotherapy demonstrated acceptable safety and favorable pharmacokinetics in patients with solid tumors, NHL, and multiple myeloma. In addition, 3 objective responses were observed in NHL.

Cereblon modulator iberdomide induces degradation of the transcription factors Ikaros and Aiolos: immunomodulation in healthy volunteers and relevance to systemic lupus erythematosus.

OBJECTIVES: IKZF1 and IKZF3 (encoding transcription factors Ikaros and Aiolos) are susceptibility loci for systemic lupus erythematosus (SLE). The pharmacology of iberdomide (CC-220), a cereblon (CRBN) modulator targeting Ikaros and Aiolos, was studied in SLE patient cells and in a phase 1 healthy volunteer study. METHODS: CRBN, IKZF1 and IKZF3 gene expression was measured in peripheral blood mononuclear cells (PBMC) from patients with SLE and healthy volunteers. Ikaros and Aiolos protein levels were measured by Western blot and flow cytometry. Anti-dsDNA and anti-phospholipid autoantibodies were measured in SLE PBMC cultures treated for 7 days with iberdomide. Fifty-six healthy volunteers were randomised to a single dose of iberdomide (0.03-6 mg, n=6 across seven cohorts) or placebo (n=2/cohort). CD19+ B cells, CD3+ T cells and intracellular Aiolos were measured by flow cytometry. Interleukin (IL)-2 and IL-1ß production was stimulated with anti-CD3 and lipopolysaccharide, respectively, in an ex vivo whole blood assay. RESULTS: SLE patient PBMCs expressed significantly higher CRBN (1.5-fold), IKZF1 (2.1-fold) and IKZF3 (4.1-fold) mRNA levels compared with healthy volunteers. Iberdomide significantly reduced Ikaros and Aiolos protein levels in B cells, T cells and monocytes. In SLE PBMC cultures, iberdomide inhibited anti-dsDNA and anti-phospholipid autoantibody production (IC50 ≈10 nM). Single doses of iberdomide (0.3-6 mg) in healthy volunteers decreased intracellular Aiolos (minimum mean per cent of baseline: ≈12%-28% (B cells); ≈0%-33% (T cells)), decreased absolute CD19+ B cells, increased IL-2 and decreased IL-1ß production ex vivo. CONCLUSIONS: These findings demonstrate pharmacodynamic activity of iberdomide and support its further clinical development for the treatment of SLE. TRIAL REGISTRATION NUMBER: NCT01733875; Results.