Homologous recombination suppresses transgenerational DNA end resection and chromosomal instability in fission yeast.

Chromosomal instability (CIN) drives cell-to-cell heterogeneity, and the development of genetic diseases, including cancer. Impaired homologous recombination (HR) has been implicated as a major driver of CIN, however, the underlying mechanism remains unclear. Using a fission yeast model system, we establish a common role for HR genes in suppressing DNA double-strand break (DSB)-induced CIN. Further, we show that an unrepaired single-ended DSB arising from failed HR repair or telomere loss is a potent driver of widespread CIN. Inherited chromosomes carrying a single-ended DSB are subject to cycles of DNA replication and extensive end-processing across successive cell divisions. These cycles are enabled by Cullin 3-mediated Chk1 loss and checkpoint adaptation. Subsequent propagation of unstable chromosomes carrying a single-ended DSB continues until transgenerational end-resection leads to fold-back inversion of single-stranded centromeric repeats and to stable chromosomal rearrangements, typically isochromosomes, or to chromosomal loss. These findings reveal a mechanism by which HR genes suppress CIN and how DNA breaks that persist through mitotic divisions propagate cell-to-cell heterogeneity in the resultant progeny.

Treatment satisfaction in patients with hidradenitis suppurativa: A real-world survey from the EU5 and US.

Introduction Hidradenitis suppurativa (HS) is a debilitating, inflammatory skin disorder. Treatment strategies in patients with HS are challenging; real-world evidence in a HS population is warranted for greater disease understanding. The objective of this analysis was to describe real-world treatment patterns and treatment satisfaction in patients with HS. Methods This was a cross-sectional market research survey with retrospective data collection in patients with HS from the United States and five European countries (France, Germany, Italy, Spain, United Kingdom) between November 2020 and April 2021, using physician- and patient-reported surveys. Eligible physicians were general dermatologists actively managing patients with HS; dermatologists were required to have consulted with ≥2 patients with HS in the previous 12 months. Adult (≥18 years) and adolescent (10‒17 years) HS patients visiting a participating dermatologist were included. Outcomes included treatment patterns, flare status, treatments prescribed in response to flares, previous surgeries, barriers to biologics, and patient- and physician-reported satisfaction with the disease control provided by treatment. Results Survey data from 1787 patients were collected from 312 dermatologists. The most frequently prescribed treatments were topicals, oral antibiotics, and antiseptic washes/creams at diagnosis and sampling. At sampling, biologics were more frequently prescribed in patients with more severe disease (prescribed in 26.6%, 31.0% and 52.4% of patients with mild, moderate, and severe disease, respectively); oral antibiotics (48.8%), topicals (37.4%), and biologics (34.3%) were the most frequently prescribed treatment classes in response to a flare. Of patients currently not receiving a biologic, dermatologists reported that 18.9% of patients' condition warranted their use. Approximately one quarter of dermatologists (24.5%) and patients (27.4%) were not satisfied with current treatment; of patients who were dissatisfied, 12.8% reported they would never raise their dissatisfaction with their doctor. Conclusion These real-world data suggest a high disease burden and potential undertreatment in patients with HS. Patients received multiple treatments, and a notable proportion underwent surgery. Robustly integrating the patient voice in HS treatment decisions may lead to better outcomes and improved treatment satisfaction.

Secukinumab efficacy in patients with hidradenitis suppurativa assessed by the International Hidradenitis Suppurativa Severity Score System (IHS4): A post hoc analysis of the SUNSHINE and SUNRISE trials.

INTRODUCTION: The International Hidradenitis Suppurativa Severity Score System (IHS4) is a validated tool that measures inflammatory lesions, including draining tunnels, in hidradenitis suppurativa (HS). OBJECTIVE: To evaluate secukinumab efficacy using IHS4 in patients with moderate to severe HS. METHODS: Data from the SUNSHINE and SUNRISE trials, which assessed subcutaneous secukinumab 300 mg every 2 (SECQ2W) and 4 (SECQ4W) weeks in adults with moderate to severe HS, were analyzed. Assessments included changes from baseline in IHS4 and severity classification up to Week 52; IHS4-55, IHS4-75, IHS4-90 responses (55%, 75% and 90% reduction in IHS4) and concordance between IHS4-55 and HS clinical response (HiSCR), at Weeks 16 and 52. RESULTS: In total, 1084 patients (SECQ2W = 361; SECQ4W = 360; placebo = 363) were analyzed. At Week 16, SECQ2W and SECQ4W demonstrated a numerically higher reduction in IHS4 from baseline versus placebo (adjusted mean [95% CI]: -10.80 [-12.30 to -9.30] and -9.46 [-10.96 to -7.96] vs. -4.92 [-6.43 to -3.41]); the reduction was maintained until Week 52 in both dose regimens. A greater proportion of patients achieved IHS4-55 with SECQ2W (43.4%) and SECQ4W (39.5%) versus placebo (31.5%) at Week 16, with further improvement at Week 52. Similar trends were observed for IHS4-75 and IHS4-90 responses. While no patients had mild disease based on IHS4 (80.7% had severe and 19.3% had moderate HS) at baseline, a greater proportion of patients were categorized as having mild disease at Week 16 in the SECQ2W (25.9%) and SECQ4W (24.0%) groups versus placebo (16.4%); this trend continued up to Week 52 in both dose regimens. Strong concordance (>85%) was observed between IHS4-55 and HiSCR. CONCLUSIONS: Both SECQ2W and SECQ4W demonstrated efficacy in improving treatment response as measured by IHS4 and reducing disease severity versus placebo at Week 16 and these improvements were sustained through Week 52. These findings support that the dynamic and dichotomous IHS4 can efficiently detect treatment response changes in clinical trial settings.

Secukinumab versus guselkumab in the complete resolution of ustekinumab-resistant psoriatic plaques: The ARROW study.

Interleukin (IL)-23-independent IL-17A production has been suggested to be involved in persistent manifestations of psoriatic disease, including anti-IL-12/23-refractory psoriatic plaques; this study aimed to test this hypothesis by investigating the clinical and molecular effects of direct IL-17A (with secukinumab) versus selective IL-23 inhibition (with guselkumab) in patients with anti-IL-12/23 (ustekinumab)-refractory psoriatic plaques. A 16-week, randomized, open-label, parallel-group, Phase IIa study (ARROW, NCT03553823) was conducted in patients with ≥1 active psoriatic plaque (total clinical score [TCS] ≥6) at screening despite treatment with ustekinumab, and a Psoriasis Area and Severity Index (PASI) score 1-10. Patients were randomized 1:1 to receive secukinumab 300 mg (n = 20) or guselkumab 100 mg (n = 20). Biopsies from one refractory ('target plaque') were obtained at baseline and Week 16. The primary endpoint was the proportion of patients whose ustekinumab-refractory target plaque achieved clear/almost clear status (TCS 0-2) at Week 16. Transcriptomic and histological analyses were conducted on target plaques to determine the molecular effects of direct IL-17A versus selective IL-23 inhibition. At Week 16, target plaque clear/almost clear status was achieved in 60.0% of patients treated with secukinumab versus 40.0% of patients treated with guselkumab (p = 0.1715). Molecular analyses identified that secukinumab modulated a greater proportion of psoriasis disease transcriptome genes (72.1% vs. 48.0%) and resulted in more histological responders (72.2% vs. 53.3%) compared with guselkumab. Secukinumab demonstrated a greater clinical and molecular effect on ustekinumab-refractory psoriatic plaques versus guselkumab. These results are consistent with the hypothesis that IL-23-independent IL-17 mechanisms may be relevant to the inflammation driving refractory manifestations of psoriasis.

Patient Perspectives on Psoriatic Disease Burden: Results from the Global Psoriasis and Beyond Survey.

BACKGROUND: Patients' understanding of the systemic nature of psoriatic disease (PsD) remains insufficiently explored. OBJECTIVES: The objective of this study was to assess patients' understanding of PsD, associated comorbidities, disease burden, and relationships with healthcare professionals (HCPs). METHODS: Psoriasis and Beyond was a cross-sectional, quantitative online survey conducted in patients with a self-reported, physician-given diagnosis of moderate to severe psoriasis (body surface area [BSA] >5% to <10%, affecting sensitive and/or prominent body parts or BSA ≥10%) at its worst, with/without psoriatic arthritis (PsA). Patients were recruited through online panels by the Institut de Publique Sondage d'Opinion Secteur (Ipsos SA) and patient advocacy groups. RESULTS: Overall, 4,978 respondents with psoriasis completed the online survey from 20 countries across Australia, Asia, Europe, and the Americas; 30% of patients also reported having concomitant PsA. Overall, 69% of patients with psoriasis had heard that their disease was part of a systemic disease, and 60% had heard of the term "psoriatic disease." Despite this, recognition of common manifestations and comorbidities associated with PsD was low. Among psoriasis-only patients (n = 3,490), 38% screened positive using the Psoriasis Epidemiology Screening Tool (PEST), indicative of potential PsA. Overall, 48% of patients reported that their disease had a very large to extremely large effect on quality of life (QoL; Dermatology Life Quality Index [DLQI] score, 11-30); only 13% of patients reported no impact of the disease on QoL (DLQI, 0-1). Most patients had experienced stigma and discrimination (82%) and a negative impact on relationships (81%) in their lives. Overall, 59% of patients were not involved in deciding their treatment goals: 58% of all treated patients (n = 4,757) and 64% of treated patients with concomitant PsA (n = 1,409) were satisfied with their current treatment. CONCLUSIONS: These results highlight that patients may not fully understand the systemic nature of their disease, were frequently uninvolved in deciding treatment goals, and were often not satisfied with their current treatment. Increasing patients' participation in their care can facilitate shared decision-making between patients and HCPs, which may result in better treatment adherence and patient outcomes. Furthermore, these data indicate that policies should be implemented to protect against stigma and discrimination, which are commonly experienced by patients with psoriasis.

Secukinumab demonstrates high and sustained efficacy in nail psoriasis: post hoc analysis from phase III trials in patients with psoriatic arthritis.

Secukinumab showed consistent and sustained efficacy in clearing nail psoriasis in patients with psoriatic arthritis, with or without axial manifestations, irrespective of severity of nail involvement. Reduction of nail disease was also associated with response across all musculoskeletal and skin manifestations of psoriatic arthritis.

The spliceosome-associated protein Nrl1 suppresses homologous recombination-dependent R-loop formation in fission yeast.

The formation of RNA-DNA hybrids, referred to as R-loops, can promote genome instability and cancer development. Yet the mechanisms by which R-loops compromise genome instability are poorly understood. Here, we establish roles for the evolutionarily conserved Nrl1 protein in pre-mRNA splicing regulation, R-loop suppression and in maintaining genome stability. nrl1Δ mutants exhibit endogenous DNA damage, are sensitive to exogenous DNA damage, and have defects in homologous recombination (HR) repair. Concomitantly, nrl1Δ cells display significant changes in gene expression, similar to those induced by DNA damage in wild-type cells. Further, we find that nrl1Δ cells accumulate high levels of R-loops, which co-localize with HR repair factors and require Rad51 and Rad52 for their formation. Together, our findings support a model in which R-loop accumulation and subsequent DNA damage sequesters HR factors, thereby compromising HR repair at endogenously or exogenously induced DNA damage sites, leading to genome instability.

The DNA damage checkpoint pathway promotes extensive resection and nucleotide synthesis to facilitate homologous recombination repair and genome stability in fission yeast.

DNA double-strand breaks (DSBs) can cause chromosomal rearrangements and extensive loss of heterozygosity (LOH), hallmarks of cancer cells. Yet, how such events are normally suppressed is unclear. Here we identify roles for the DNA damage checkpoint pathway in facilitating homologous recombination (HR) repair and suppressing extensive LOH and chromosomal rearrangements in response to a DSB. Accordingly, deletion of Rad3(ATR), Rad26ATRIP, Crb2(53BP1) or Cdc25 overexpression leads to reduced HR and increased break-induced chromosome loss and rearrangements. We find the DNA damage checkpoint pathway facilitates HR, in part, by promoting break-induced Cdt2-dependent nucleotide synthesis. We also identify additional roles for Rad17, the 9-1-1 complex and Chk1 activation in facilitating break-induced extensive resection and chromosome loss, thereby suppressing extensive LOH. Loss of Rad17 or the 9-1-1 complex results in a striking increase in break-induced isochromosome formation and very low levels of chromosome loss, suggesting the 9-1-1 complex acts as a nuclease processivity factor to facilitate extensive resection. Further, our data suggest redundant roles for Rad3ATR and Exo1 in facilitating extensive resection. We propose that the DNA damage checkpoint pathway coordinates resection and nucleotide synthesis, thereby promoting efficient HR repair and genome stability.

DNA double-strand break repair pathways, chromosomal rearrangements and cancer.

Chromosomal rearrangements, which can lead to oncogene activation and tumour suppressor loss, are a hallmark of cancer cells. Such outcomes can result from both the repair and misrepair of DNA ends, which arise from a variety of lesions including DNA double strand breaks (DSBs), collapsed replication forks and dysfunctional telomeres. Here we review the mechanisms by which non-homologous end joining (NHEJ) and homologous recombination (HR) repair pathways can both promote chromosomal rearrangements and also suppress them in response to such lesions, in accordance with their increasingly recognised tumour suppressor function. Further, we consider how chromosomal rearrangements, together with a modular approach towards understanding their etiology, may be exploited for cancer therapy.

Nail Involvement as a Predictor of Differential Treatment Effects of Secukinumab Versus Ustekinumab in Patients with Moderate to Severe Psoriasis.

INTRODUCTION: Patients with plaque psoriasis may experience varying levels of treatment response to different biologics, based on phenotypic characteristics and underlying genetic factors. Nail psoriasis is a common manifestation of psoriasis (approx. 50% of patients) and has been linked to the human leukocyte antigen-C*0602 (HLA-C*0602) allele, which in turn has been associated with differential treatment responses to certain drugs. Here we investigate whether nail involvement in patients with psoriasis can predict differential skin responses to two biologics with different modes of action, namely secukinumab (anti-interleukin-17A) and ustekinumab (anti-interleukin-12/23), to ultimately guide treatment choice. METHODS: Data were pooled from the CLEAR and CLARITY studies and stratified post hoc by nail involvement status at baseline. Psoriasis Area and Severity Index (PASI) 75 and 90 responses over 52 weeks and absolute PASI ≤ 3, ≤ 1, and 0 values at weeks 16 and 52, were assessed. RESULTS: Based on the medical history, 30.4% (269/886) of the patients in the secukinumab arm and 29.7% (265/891) of patients in the ustekinumab arm presented with nail involvement. Nail involvement status had little to no impact on the efficacy of secukinumab, as comparable responses were achieved for patients with and without nail involvement in terms of PASI 75/90, ≤ 3, and 0 responses; slightly lower PASI ≤ 1 reponses were achieved in patients with nail involvement. In the ustekinumab arm, patients with nail involvement achieved lower responses across all endpoints. CONCLUSIONS: These findings indicate that nail involvement can serve as an observable prognostic factor for efficacy in skin psoriasis treatment and guide the choice between secukinumab and ustekinumab. TRIAL REGISTRATION: CLEAR: NCT02074982; CLARITY: NCT02826603.

Lower Limbs are the Most Difficult-to-Treat Body Region of Patients with Psoriasis: Pooled Analysis of CLEAR and CLARITY Studies of Secukinumab Versus Ustekinumab by Body Region.

BACKGROUND: The impact of psoriasis, response to treatment, and patients' perceptions of treatment satisfaction vary by body area. OBJECTIVES: We aimed to evaluate the level of response in lower limbs versus other body regions in patient with moderate to severe psoriasis treated with secukinumab and ustekinumab. METHODS: Data were pooled from CLEAR and CLARITY trials, which included patients with moderate to severe plaque psoriasis (Psoriasis Area and Severity Index [PASI] score of ≥ 12) aged ≥ 18 years and a diagnosis of ≥ 6 months before randomisation. Patients received either secukinumab 300 mg or ustekinumab 45/90 mg. The PASI 100 responders and mean PASI scores at weeks 4, 12, 16, 28, 40 and 52 in the head and neck, trunk, upper limbs and lower limbs were measured. RESULTS: At baseline, analysis of PASI scores for each body region revealed that the lower limbs were the most severely affected body region in both treatment arms (mean PASI scores: secukinumab 24.0; ustekinumab 24.4). For both drugs, the highest clearance rates at week 52 were achieved in the trunk (secukinumab 85.2% vs ustekinumab 68.7%) and head and neck (80.7% vs 68.9%), followed by the upper limbs (72.6% vs 61.9%) and lower limbs (68.1% vs 57.2%). At week 52, the mean PASI score was higher in the lower limbs in both treatment arms versus other body regions. CONCLUSIONS: Lower limbs were the most severely affected and most difficult-to-treat regions in patients with psoriasis. Consistent with the individual results of both studies, secukinumab demonstrated numerically faster and higher skin clearance than ustekinumab in all body regions. CLINICAL TRIAL REGISTRATION: CLEAR: NCT02074982; CLARITY: NCT02826603.

Impact of Psoriatic Disease on Quality of Life: Interim Results of a Global Survey.

INTRODUCTION: Psoriatic disease (PsD) is a chronic systemic disorder affecting numerous body areas, including skin and joints. Patients' perspectives regarding understanding their disease and dialogue with healthcare professionals (HCPs) on treatment strategies is becoming increasingly important in the holistic management of PsD. The study aim was to determine patients' understanding of the systemic nature of psoriasis and psoriatic arthritis (PsA) and the associated burden of living with these diseases. The relationship between patient and HCP was also evaluated. METHODS: Psoriasis and Beyond: The Global Psoriatic Disease Survey was a cross-sectional, quantitative online survey, conducted in patients with moderate to severe plaque psoriasis with or without concomitant PsA. Here, we report interim analysis results. RESULTS: A total of 1678 respondents from 11 countries were included. Overall, 31% of patients with psoriasis reported concomitant PsA, 80% of whom considered their PsA severity as moderately or highly active. In total, 63% of patients had heard the term "psoriatic disease". Few patients were aware of psoriasis manifestations (PsA, 29%; axial symptoms, 18%) or comorbidities (obesity, 21%; cardiovascular disease, 18%). Among patients with psoriasis and concomitant PsA, 70% reported swollen and tender joints, especially of the finger(s) and/or toe(s). Most patients (84%) experienced stigma and discrimination and reported a negative impact of their disease on work, emotions, and relationships. Overall, 42% of patients had never discussed treatment goals with their HCP. Patients who were dissatisfied with their current treatment (psoriasis, 15%; psoriasis with PsA, 14%) reported incomplete relief of skin symptoms (57%) and joint symptoms (45%) as primary reasons for dissatisfaction. CONCLUSIONS: Despite many patients having heard the term "psoriatic disease", the majority were unaware of the systemic nature and increased risk of comorbidities associated with PsD. This interim analysis highlights the need for patient education, productive patient-HCP dialogue, and shared decision-making in optimal disease management.