Maori Medical Student and Physician Exposure to Racism, Discrimination, Harassment, and Bullying.

Importance: Discrimination, bullying, and harassment in medicine have been reported internationally, but exposures for Indigenous medical students and physicians, and for racism specifically, remain less examined. Objective: To examine the prevalence of racism, discrimination, bullying, and harassment for Maori medical students and physicians in New Zealand and associations with demographic and clinical characteristics. Design, Setting, and Participants: This cross-sectional study used data from an anonymous national survey of Maori medical students and physicians in New Zealand in late 2021 and early 2022. Data were analyzed from March 2022 to April 2024. Exposures: Age, gender, marginalized status (ie, in addition to being Maori, belonging to other groups traditionally marginalized or underrepresented in medicine), year of medical school, year of graduation, and main work role. Main Outcomes and Measures: Direct and witnessed racism, discrimination, bullying, and harassment were measured as any experience in the last year and ever. Any exposure to negative comments about social groups and witnessing discriminatory treatment toward Maori patients or whanau (extended family). Considering leaving medicine, including because of mistreatment, was measured. Results: Overall, 205 Maori medical students (median [IQR] age, 23.1 [21.6-24.3] years; 137 [67.2%] women) and 200 physicians (median [IQR] age, 36.6 [30.1-45.3] years; 123 [62.8%] women) responded. Direct and witnessed exposure to racism (184 students [91.5%]; 176 physicians [90.7%]) and discrimination (176 students [85.9%]; 179 physicians [89.5%]) ever in medical education, training, or work environments was common. Ever exposure to witnessed and direct bullying (123 students [66.5%]; 150 physicians [89.3%]) and harassment (73 students [39.5%]; 112 physicians [66.7%]) was also common. Most respondents reported witnessing Maori patients or their whanau being treated badly in clinical settings, in direct interactions (67 students [57.8%]; 112 physicians [58.9%]) or behind their backs (87 students [75.0%]; 138 physicians [72.6%]). One-quarter of Maori medical students (45 students), and 37.0% of physicians (61 physicians) had considered leaving or taken a break from medicine because of these experiences. Additional marginalized statuses were significantly associated with any direct experience of mistreatment in the last year for students and physicians. Exposure to some forms of mistreatment were also significantly associated with higher likelihood of thinking about leaving or taking a break from medicine for physicians. Conclusions and Relevance: In this study, Maori medical students and physicians reported high exposure to multiple forms of racism, discrimination, bullying, and harassment in medical education, training, and work environments, requiring an urgent response from medical institutions.

Telomerase inhibition is an effective therapeutic strategy in TERT promoter-mutant glioblastoma models with low tumor volume.

BACKGROUND: Glioblastoma is one of the most lethal forms of cancer, with 5-year survival rates of only 6%. Glioblastoma-targeted therapeutics have been challenging to develop due to significant inter- and intra-tumoral heterogeneity. Telomerase reverse transcriptase gene (TERT) promoter mutations are the most common known clonal oncogenic mutations in glioblastoma. Telomerase is therefore considered to be a promising therapeutic target against this tumor. However, an important limitation of this strategy is that cell death does not occur immediately after telomerase ablation, but rather after several cell divisions required to reach critically short telomeres. We, therefore, hypothesize that telomerase inhibition would only be effective in glioblastomas with low tumor burden. METHODS: We used CRISPR interference to knock down TERT expression in TERT promoter-mutant glioblastoma cell lines and patient-derived models. We then measured viability using serial proliferation assays. We also assessed for features of telomere crisis by measuring telomere length and chromatin bridge formation. Finally, we used a doxycycline-inducible CRISPR interference system to knock down TERT expression in vivo early and late in tumor development. RESULTS: Upon TERT inactivation, glioblastoma cells lose their proliferative ability over time and exhibit telomere shortening and chromatin bridge formation. In vivo, survival is only prolonged when TERT knockdown is induced shortly after tumor implantation, but not when the tumor burden is high. CONCLUSIONS: Our results support the idea that telomerase inhibition would be most effective at treating glioblastomas with low tumor burden, for example in the adjuvant setting after surgical debulking and chemoradiation.

Oral care, loss of personal identity and dignity in residential care homes.

OBJECTIVE: The UK National Institute of Clinical Excellence (NICE) guidelines recommend that care staff who provide daily personal care to residents: "Understand the importance of residents' oral health and the potential effect on their general health, well-being and dignity." The aim of this study was to explore residents' views and perspectives of dental care in care homes in order to understand how to deliver this care. METHOD: Care homes were identified using care home inspection reports for Wales, the UK. Care homes for older people with residents having mental capacity to consent were invited to participate. Data were collected using semi-structured one-to-one interviews with care home residents, care home managers and oral healthcare leads. Interviews were audio recorded, transcribed and analysed using a thematic approach to data. Analysis was assisted by NVivo 10 software. Data collection was completed when no new themes emerged. RESULTS: This analysis presents findings from 26 interviews with residents, across five care homes. Going into care was associated with a loss of identity. Having teeth and looking after teeth (natural teeth or dentures) was part of keeping that identity. All prioritised privacy, pride and independence above effective oral hygiene. Oral hygiene was viewed as a very private event. Carers adapted oral care, to balance time constraints, care, privacy and dignity. Teeth were a part of personal pride to the extent that two residents said they did not want to die without dentures in their mouths. CONCLUSION: Whilst oral care is important to residents, dignity and privacy are often more important; care routines and practices are adapted around this. Carers need to adopt an individualised, pragmatic and sensitive approach to oral care to account for personal dignity when looking after residents to be able to provide appropriate oral care in accordance with guidance. Members of the dental team need to support carers to provide effective oral care, which allows dignified and effective care.

ATRX modulates the escape from a telomere crisis.

Telomerase activity is the principal telomere maintenance mechanism in human cancers, however 15% of cancers utilise a recombination-based mechanism referred to as alternative lengthening of telomeres (ALT) that leads to long and heterogenous telomere length distributions. Loss-of-function mutations in the Alpha Thalassemia/Mental Retardation Syndrome X-Linked (ATRX) gene are frequently found in ALT cancers. Here, we demonstrate that the loss of ATRX, coupled with telomere dysfunction during crisis, is sufficient to initiate activation of the ALT pathway and that it confers replicative immortality in human fibroblasts. Additionally, loss of ATRX combined with a telomere-driven crisis in HCT116 epithelial cancer cells led to the initiation of an ALT-like pathway. In these cells, a rapid and precise telomeric elongation and the induction of C-circles was observed; however, this process was transient and the telomeres ultimately continued to erode such that the cells either died or the escape from crisis was associated with telomerase activation. In both of these instances, telomere sequencing revealed that all alleles, irrespective of whether they were elongated, were enriched in variant repeat types, that appeared to be cell-line specific. Thus, our data show that the loss of ATRX combined with telomere dysfunction during crisis induces the ALT pathway in fibroblasts and enables a transient activation of ALT in epithelial cells.

Internal tsunamigenesis and ocean mixing driven by glacier calving in Antarctica.

Ocean mixing around Antarctica exerts key influences on glacier dynamics and ice shelf retreats, sea ice, and marine productivity, thus affecting global sea level and climate. The conventional paradigm is that this is dominated by winds, tides, and buoyancy forcing. Direct observations from the Antarctic Peninsula demonstrate that glacier calving triggers internal tsunamis, the breaking of which drives vigorous mixing. Being widespread and frequent, these internal tsunamis are at least comparable to winds, and much more important than tides, in driving regional shelf mixing. They are likely relevant everywhere that marine-terminating glaciers calve, including Greenland and across the Arctic. Calving frequency may change with higher ocean temperatures, suggesting possible shifts to internal tsunamigenesis and mixing in a warming climate.

Aerosol and splatter generation with rotary handpieces used in restorative and orthodontic dentistry: a systematic review.

INTRODUCTION: The COVID-19 pandemic has caused major disruptions in dental care globally, in part due to the potential for contaminated aerosol to be generated by dental activities. This systematic review assesses the literature for changes in aerosol-contamination levels when rotary instruments are used, (1) as distance increases from patient's mouth; (2) as time passes after the procedure; and (3) when using different types of handpieces. METHODS: The review methods and reporting are in line with PRISMA statements. A structured search was conducted over five platforms (September 2021). Studies were assessed independently by two reviewers. To be eligible studies had to assess changes in levels of aerosol contamination over different distances, and time points, with rotary hand instruments. Studies' methodologies and the sensitivity of the contamination-measurement approaches were evaluated. Results are presented descriptively. RESULTS: From 422 papers identified, 23 studies were eligible. All investigated restorative procedures using rotary instruments and one study additionally looked at orthodontic bracket adhesive material removal. The results suggest contamination is significantly reduced over time and distance. However, for almost all studies that investigated these two factors, the sizes of the contaminated particles were not considered, and there were inconclusive findings regarding whether electric-driven handpieces generate lower levels of contaminated particles. CONCLUSION: Aerosol contamination levels reduce as distances, and post-procedure times increase. However, there was sparce and inconsistent evidence on the clearing time and no conclusions could be drawn. High-speed handpieces produce significantly higher levels of contamination than slow-speed ones, and to a lesser extent, micro-motor handpieces. However, when micro-motor handpieces were used with water, the contamination levels rose and were similar to high-speed handpiece contamination levels.

The development and application of a chairside oral health risk and need stratification tool in general dental services.

OBJECTIVE: To describe the development and application of the Assessment of Clinical Oral Risks and Needs (ACORN) stratification tool based on a traffic light system in National Health Service (NHS) general dental services (GDS) Wales, UK. MATERIALS AND METHODS: This was a secondary analysis of routinely-collected dental care data. All courses of treatment provided in dental practices participating in NHS GDS Reform Programme between July 2018 and September 2019, in which an ACORN assessment and age were recorded were included in the analysis. RESULTS: A total of 236,490 subjects contributed 339,933 courses of treatment during the study period. 'Amber' and 'red' ACORN outcomes were associated with more courses of treatment per annum than 'green' outcomes. Outcomes indicating an increased risk of decay or other dental problems were associated with a greater likelihood of several operative treatment items. Patients at greater risk of poor periodontal health were more likely to receive extractions and dentures than low-risk patients. Patients were most likely to either remain in the same ACORN outcome categories or move to a healthier state between assessments. CONCLUSION: More research is required to understand the utility of the ACORN tool in risk communication and behaviour change.

If the public can vaccinate, why not students? Review of a student nurse placement in a mass vaccination centre.

Delivery of the COVID-19 vaccine has been made possible in part through the use of mass vaccination centres (MVCs). The primary legal framework underpinning the MVC programme is a national protocol enabling registered and non-registered healthcare workers to contribute to the safe and effective administration of the vaccine. The national protocol provided a vehicle for an innovative supervised student nurse placement within an MVC in south Wales. This placement, for undergraduate pre-registration student nurses, formed part of a service improvement project. Through student feedback prior to, and following, the short placement, the learning was unequivocal in terms of knowledge and skills acquisition related to safe and effective vaccine administration, with students providing clear feedback on the positive nature of the placement experience. A placement within an MVC offers a rich educational experience for student nurses, which as yet appears to be underutilised across the UK.

Symptoms of Prenatal Depression Associated with Shorter Telomeres in Female Placenta.

BACKGROUND: Depression is a common mood disorder during pregnancy impacting one in every seven women. Children exposed to prenatal depression are more likely to be born at a low birth weight and develop chronic diseases later in life. A proposed hypothesis for this relationship between early exposure to adversity and poor outcomes is accelerated aging. Telomere length has been used as a biomarker of cellular aging. We used high-resolution telomere length analysis to examine the relationship between placental telomere length distributions and maternal mood symptoms in pregnancy. METHODS: This study utilised samples from the longitudinal Grown in Wales (GiW) study. Women participating in this study were recruited at their presurgical appointment prior to a term elective caesarean section (ELCS). Women completed the Edinburgh Postnatal Depression Scale (EPDS) and trait subscale of the State-Trait Anxiety Inventory (STAI). Telomere length distributions were generated using single telomere length analysis (STELA) in 109 term placenta (37-42 weeks). Multiple linear regression was performed to examine the relationship between maternally reported symptoms of depression and anxiety at term and mean placental telomere length. RESULTS: Prenatal depression symptoms were significantly negatively associated with XpYp telomere length in female placenta (B = -0.098, p = 0.026, 95% CI -0.184, -0.012). There was no association between maternal depression symptoms and telomere length in male placenta (B = 0.022, p = 0.586, 95% CI -0.059, 0.103). There was no association with anxiety symptoms and telomere length for either sex. CONCLUSION: Maternal prenatal depression is associated with sex-specific differences in term placental telomeres. Telomere shortening in female placenta may indicate accelerated placental aging.

#EEGManyLabs: Investigating the replicability of influential EEG experiments.

There is growing awareness across the neuroscience community that the replicability of findings about the relationship between brain activity and cognitive phenomena can be improved by conducting studies with high statistical power that adhere to well-defined and standardised analysis pipelines. Inspired by recent efforts from the psychological sciences, and with the desire to examine some of the foundational findings using electroencephalography (EEG), we have launched #EEGManyLabs, a large-scale international collaborative replication effort. Since its discovery in the early 20th century, EEG has had a profound influence on our understanding of human cognition, but there is limited evidence on the replicability of some of the most highly cited discoveries. After a systematic search and selection process, we have identified 27 of the most influential and continually cited studies in the field. We plan to directly test the replicability of key findings from 20 of these studies in teams of at least three independent laboratories. The design and protocol of each replication effort will be submitted as a Registered Report and peer-reviewed prior to data collection. Prediction markets, open to all EEG researchers, will be used as a forecasting tool to examine which findings the community expects to replicate. This project will update our confidence in some of the most influential EEG findings and generate a large open access database that can be used to inform future research practices. Finally, through this international effort, we hope to create a cultural shift towards inclusive, high-powered multi-laboratory collaborations.

Genotoxicity and Epigenotoxicity of Carbazole-Derived Molecules on MCF-7 Breast Cancer Cells.

The carbazole compounds PK9320 (1-(9-ethyl-7-(furan-2-yl)-9H-carbazol-3-yl)-N-methylmethanamine) and PK9323 (1-(9-ethyl-7-(thiazol-4-yl)-9H-carbazol-3-yl)-N-methylmethanamine), second-generation analogues of PK083 (1-(9-ethyl-9H-carbazol-3-yl)-N-methylmethanamine), restore p53 signaling in Y220C p53-mutated cancer cells by binding to a mutation-induced surface crevice and acting as molecular chaperones. In the present paper, these three molecules have been tested for mutant p53-independent genotoxic and epigenomic effects on wild-type p53 MCF-7 breast adenocarcinoma cells, employing a combination of Western blot for phospho-γH2AX histone, Comet assay and methylation-sensitive arbitrarily primed PCR to analyze their intrinsic DNA damage-inducing and DNA methylation-changing abilities. We demonstrate that small modifications in the substitution patterns of carbazoles can have profound effects on their intrinsic genotoxic and epigenetic properties, with PK9320 and PK9323 being eligible candidates as "anticancer compounds" and "anticancer epi-compounds" and PK083 a "damage-corrective" compound on human breast adenocarcinoma cells. Such different properties may be exploited for their use as anticancer agents and chemical probes.

Dental periodontal procedures: a systematic review of contamination (splatter, droplets and aerosol) in relation to COVID-19.

INTRODUCTION: The emergence of the SARS-CoV-2 virus and subsequent COVID-19 pandemic has had a significant effect on the delivery of routine dentistry; and in particular, periodontal care across the world. This systematic review examines the literature relating to splatter, droplet settle and aerosol for periodontal procedures and forms part of a wider body of research to understand the risk of contamination in relation to periodontal care procedures relevant to COVID-19. METHODS: A search of the literature was carried out using key terms and MeSH words relating to the review questions. Sources included Medline (OVID), Embase (OVID), Cochrane Central Register of Controlled Trials, Scopus, Web of Science and LILACS, ClinicalTrials.Gov . Studies meeting inclusion criteria were screened in duplicate and data extraction was carried out using a template. All studies were assessed for methodological quality and sensitivity. Narrative synthesis was undertaken. RESULTS: Fifty studies were included in the review with procedures including ultrasonic scaling (n = 44), air polishing (n = 4), prophylaxis (n = 2) and hand scaling (n = 3). Outcomes included bacterial (colony-forming units e.g. on settle plates) or blood contamination (e.g. visible splatter) and non bacterial, non blood (e.g. chemiluminescence or coloured dyes) contamination. All studies found contamination at all sites although the contamination associated with hand scaling was very low. Contamination was identified in all of the studies even where suction was used at baseline. Higher power settings created greater contamination. Distribution of contamination varied in relation to operator position and was found on the operator, patient and assistant with higher levels around the head of the operator and the mouth and chest of the patient. Settle was identified 30 min after treatments had finished but returned to background levels when measured at or after an hour. The evidence was generally low to medium quality and likely to underestimate contamination. CONCLUSION: Ultrasonic scaling, air polishing and prophylaxis procedures produce contamination (splatter, droplets and aerosol) in the presence of suction, with a small amount of evidence showing droplets taking between 30 min and 1 h to settle. Consideration should be given to infection control, areas of cleaning particularly around the patient and appropriate personal protective equipment, with particular attention to respiratory, facial and body protection for these procedures. In addition, the use of lower power settings should be considered to reduce the amount and spread of contamination.

Cost-effectiveness of the reverse total shoulder arthroplasty. Does indication affect outcome?

BACKGROUND: The primary aim of this study was to determine the cost-effectiveness of the reverse total shoulder arthroplasty in a prospective cohort of patients over a two-year post-operative period. METHODS: Patients who underwent reverse total shoulder arthroplasty were prospectively monitored for 24 months post-operatively using the Oxford Shoulder Score, Disabilities of the Arm, Shoulder and Hand questionnaire and EuroQol 5-dimensional questionnaire. Any complications or use of health care resources were recorded. The incremental cost-effectiveness ratio was used to express the cost per quality-adjusted life year gained. RESULTS: Sixty-seven patients were analysed, 46 primary reverse total shoulder arthroplasty for cuff arthropathy and 21 revisions from previous arthroplasty. Both indications had comparable peri-operative shoulder scores without significant difference. Using the mean change of EuroQol 5-dimensional questionnaire at one year, the incremental cost-effectiveness ratio was calculated at £16,827.43 per quality-adjusted life year, decreasing to £8313.48 per quality-adjusted life year at two years. Primary was associated with a lower incremental cost-effectiveness ratio at two years (primary £7596.76 vs. revision £11,748.51). The estimated post-operative life expectancy of the cohort was 6.9 years with a projected cost per quality-adjusted life year of £2438.78. CONCLUSIONS: Reverse total shoulder arthroplasty provides a cost-effective intervention with excellent patient outcomes at two years post-operatively.

CD57+ Memory T Cells Proliferate In Vivo.

A central paradigm in the field of lymphocyte biology asserts that replicatively senescent memory T cells express the carbohydrate epitope CD57. These cells nonetheless accumulate with age and expand numerically in response to persistent antigenic stimulation. Here, we use in vivo deuterium labeling and ex vivo analyses of telomere length, telomerase activity, and intracellular expression of the cell-cycle marker Ki67 to distinguish between two non-exclusive scenarios: (1) CD57+ memory T cells do not proliferate and instead arise via phenotypic transition from the CD57- memory T cell pool; and/or (2) CD57+ memory T cells self-renew via intracompartmental proliferation. Our results provide compelling evidence in favor of the latter scenario and further suggest in conjunction with mathematical modeling that self-renewal is by far the most abundant source of newly generated CD57+ memory T cells. Immunological memory therefore appears to be intrinsically sustainable among highly differentiated subsets of T cells that express CD57.

A systematic review of contamination (aerosol, splatter and droplet generation) associated with oral surgery and its relevance to COVID-19.

INTRODUCTION: The current COVID-19 pandemic caused by the SARS-CoV-2 virus has impacted the delivery of dental care globally and has led to re-evaluation of infection control standards. However, lack of clarity around what is known and unknown regarding droplet and aerosol generation in dentistry (including oral surgery and extractions), and their relative risk to patients and the dental team, necessitates a review of evidence relating to specific dental procedures. This review is part of a wider body of research exploring the evidence on bioaerosols in dentistry and involves detailed consideration of the risk of contamination in relation to oral surgery. METHODS: A comprehensive search of Medline (OVID), Embase (OVID), Cochrane Central Register of Controlled Trials, Scopus, Web of Science, LILACS and ClinicalTrials.Gov was conducted using key terms and MeSH (Medical Subject Headings) words relating to the review questions. Methodological quality including sensitivity was assessed using a schema developed to measure quality aspects of studies using a traffic light system to allow inter- and intra-study overview and comparison. A narrative synthesis was conducted for assessment of the included studies and for the synthesis of results. RESULTS: Eleven studies on oral surgery (including extractions) were included in the review. They explored microbiological (bacterial and fungal) and blood (visible and/or imperceptible) contamination at the person level (patients, operators and assistants) and/or at a wider environmental level, using settle plates, chemiluminescence reagents or air samplers; all within 1 m of the surgical site. Studies were of generally low to medium quality and highlighted an overall risk of contaminated aerosol, droplet and splatter generation during oral surgery procedures, most notably during removal of impacted teeth using rotatory handpieces. Risk of contamination and spread was increased by factors, including proximity to the operatory site, longer duration of treatment, higher procedural complexity, non-use of an extraoral evacuator and areas involving more frequent contact during treatment. CONCLUSION: A risk of contamination (microbiological, visible and imperceptible blood) to patients, dental team members and the clinical environment is present during oral surgery procedures, including routine extractions. However, the extent of contamination has not been explored fully in relation to time and distance. Variability across studies with regards to the analysis methods used and outcome measures makes it difficult to draw robust conclusions. Further studies with improved methodologies, including higher test sensitivity and consideration of viruses, are required to validate these findings.

Human Endometrial Carcinogenesis Is Associated with Significant Reduction in Long Non-Coding RNA, TERRA.

Telomeres are transcribed as long non-coding RNAs called TERRAs (Telomeric repeat containing RNA) that participate in a variety of cellular regulatory functions. High telomerase activity (TA) is associated with endometrial cancer (EC). This study aimed to examine the levels of three TERRAs, transcribed at chromosomes 1q-2q-4q-10q-13q-22q, 16p and 20q in healthy (n = 23) and pathological (n = 24) human endometrium and to examine their association with cellular proliferation, TA and telomere lengths. EC samples demonstrated significantly reduced levels of TERRAs for Chromosome 16p (Ch-16p) (p < 0.002) and Chromosome 20q (Ch-20q) (p = 0.0006), when compared with the postmenopausal samples. No significant correlation was found between TERRA levels and TA but both Ch-16p and Ch-20q TERRA levels negatively correlated with the proliferative marker Ki67 (r = -0.35, p = 0.03 and r = -0.42, p = 0.01 respectively). Evaluation of single telomere length analysis (STELA) at XpYp telomeres demonstrated a significant shortening in EC samples when compared with healthy tissues (p = 0.002). We detected TERRAs in healthy human endometrium and observed altered individual TERRA-specific levels in malignant endometrium. The negative correlation of TERRAs with cellular proliferation along with their significant reduction in EC may suggest a role for TERRAs in carcinogenesis and thus future research should explore TERRAs as potential therapeutic targets in EC.

Two subsets of stem-like CD8+ memory T cell progenitors with distinct fate commitments in humans.

T cell memory relies on the generation of antigen-specific progenitors with stem-like properties. However, the identity of these progenitors has remained unclear, precluding a full understanding of the differentiation trajectories that underpin the heterogeneity of antigen-experienced T cells. We used a systematic approach guided by single-cell RNA-sequencing data to map the organizational structure of the human CD8+ memory T cell pool under physiological conditions. We identified two previously unrecognized subsets of clonally, epigenetically, functionally, phenotypically and transcriptionally distinct stem-like CD8+ memory T cells. Progenitors lacking the inhibitory receptors programmed death-1 (PD-1) and T cell immunoreceptor with Ig and ITIM domains (TIGIT) were committed to a functional lineage, whereas progenitors expressing PD-1 and TIGIT were committed to a dysfunctional, exhausted-like lineage. Collectively, these data reveal the existence of parallel differentiation programs in the human CD8+ memory T cell pool, with potentially broad implications for the development of immunotherapies and vaccines.

Targeting Cavity-Creating p53 Cancer Mutations with Small-Molecule Stabilizers: the Y220X Paradigm.

We have previously shown that the thermolabile, cavity-creating p53 cancer mutant Y220C can be reactivated by small-molecule stabilizers. In our ongoing efforts to unearth druggable variants of the p53 mutome, we have now analyzed the effects of other cancer-associated mutations at codon 220 on the structure, stability, and dynamics of the p53 DNA-binding domain (DBD). We found that the oncogenic Y220H, Y220N, and Y220S mutations are also highly destabilizing, suggesting that they are largely unfolded under physiological conditions. A high-resolution crystal structure of the Y220S mutant DBD revealed a mutation-induced surface crevice similar to that of Y220C, whereas the corresponding pocket's accessibility to small molecules was blocked in the structure of the Y220H mutant. Accordingly, a series of carbazole-based small molecules, designed for stabilizing the Y220C mutant, also bound to and stabilized the folded state of the Y220S mutant, albeit with varying affinities due to structural differences in the binding pocket of the two mutants. Some of the compounds also bound to and stabilized the Y220N mutant, but not the Y220H mutant. Our data validate the Y220S and Y220N mutants as druggable targets and provide a framework for the design of Y220S or Y220N-specific compounds as well as compounds with dual Y220C/Y220S specificity for use in personalized cancer therapy.

Integrative analysis of spontaneous CLL regression highlights genetic and microenvironmental interdependency in CLL.

Spontaneous regression is a recognized phenomenon in chronic lymphocytic leukemia (CLL) but its biological basis remains unknown. We undertook a detailed investigation of the biological and clinical features of 20 spontaneous CLL regression cases incorporating phenotypic, functional, transcriptomic, and genomic studies at sequential time points. All spontaneously regressed tumors were IGHV-mutated with no restricted IGHV usage or B-cell receptor (BCR) stereotypy. They exhibited shortened telomeres similar to nonregressing CLL, indicating prior proliferation. They also displayed low Ki-67, CD49d, cell-surface immunoglobulin M (IgM) expression and IgM-signaling response but high CXCR4 expression, indicating low proliferative activity associated with poor migration to proliferation centers, with these features becoming increasingly marked during regression. Spontaneously regressed CLL displayed a transcriptome profile characterized by downregulation of metabolic processes as well as MYC and its downstream targets compared with nonregressing CLL. Moreover, spontaneous regression was associated with reversal of T-cell exhaustion features including reduced programmed cell death 1 expression and increased T-cell proliferation. Interestingly, archetypal CLL genomic aberrations including HIST1H1B and TP53 mutations and del(13q14) were found in some spontaneously regressing tumors, but genetic composition remained stable during regression. Conversely, a single case of CLL relapse following spontaneous regression was associated with increased BCR signaling, CLL proliferation, and clonal evolution. These observations indicate that spontaneously regressing CLL appear to undergo a period of proliferation before entering a more quiescent state, and that a complex interaction between genomic alterations and the microenvironment determines disease course. Together, the findings provide novel insight into the biological processes underpinning spontaneous CLL regression, with implications for CLL treatment.