Potentiation of anti-cancer drug activity at low intratumoral pH induced by the mitochondrial inhibitor m-iodobenzylguanidine (MIBG) and its analogue benzylguanidine (BG)

Tumour-selective acidification is of potential interest for enhanced therapeutic gain of pH sensitive drugs. In this study, we investigated the feasibility of a tumour-selective reduction of the extracellular and intracellular pH and their effect on the tumour response of selected anti-cancer drugs. In an in vitro L1210 leukaemic cell model, we confirmed enhanced cytotoxicity of chlorambucil at low extracellular pH conditions. In contrast, the alkylating drugs melphalan and cisplatin, and bioreductive agents mitomycin C and its derivative EO9, required low intracellular pH conditions for enhanced activation. Furthermore, a strong and pH-independent synergism was observed between the pH-equilibrating drug nigericin and melphalan, of which the mechanism is unclear. In radiation-induced fibrosarcoma (RIF-1) tumour-bearing mice, the extracellular pH was reduced by the mitochondrial inhibitor m-iodobenzylguanidine (MIBG) or its analogue benzylguanidine (BG) plus glucose. To simultaneously reduce the intracellular pH, MIBG plus glucose were combined with the ionophore nigericin or the Na+/H+ exchanger inhibitor amiloride and the Na+-dependent HCO3−/Cl−exchanger inhibitor 4,4′-diisothiocyanostilbene-2,2′-disulphonic acid (DIDS). Biochemical studies confirmed an effective reduction of the extracellular pH to approximately 6.2, and anti-tumour responses to the interventions indicated a simultaneous reduction of the intracellular pH below 6.6 for at least 3 h. Combined reduction of extra- and intracellular tumour pH with melphalan increased the tumour regrowth time to 200% of the pretreatment volume from 5.7 ± 0.6 days for melphalan alone to 8.1 ± 0.7 days with pH manipulation (P< 0.05). Mitomycin C related tumour growth delay was enhanced by the combined interventions from 3.8 ± 0.5 to 5.2 ± 0.5 days (P< 0.05), but only in tumours of relatively large sizes. The interventions were non-toxic alone or in combination with the anti-cancer drugs and did not affect melphalan biodistribution. In conclusion, we have developed non-toxic interventions for sustained and selective reduction of extra- and intracellular tumour pH which potentiated the tumour responses to selected anti-cancer drugs. 1999 Cancer Research Campaig

Patterns of patient-reported symptoms and association with sociodemographic and systemic sclerosis disease characteristics: a scleroderma Patient-centered Intervention Network (SPIN) Cohort cross-sectional study

Background: Systemic sclerosis is a heterogenous disease in which little is known about patterns of patient-reported symptom clusters. We aimed to identify classes of individuals with similar anxiety, depression, fatigue, sleep disturbance, and pain symptoms and to evaluate associated sociodemographic and disease-related characteristics. Methods: This multi-centre cross-sectional study used baseline data from Scleroderma Patient-centered Intervention Network Cohort participants enrolled from 2014 to 2020. Eligible participants completed the PROMIS-29 v2.0 measure. Latent profile analysis was used to identify homogeneous classes of participants based on patterns of anxiety, depression, fatigue, sleep disturbance, and pain scores. Sociodemographic and disease-related characteristics were compared across classes. Findings: Among 2212 participants, we identified five classes, including four classes with “Low” (565 participants, 26%), “Normal” (651 participants, 29%), “High” (569 participants, 26%), or “Very High” (193 participants, 9%) symptom levels across all symptoms. Participants in a fifth class, “High Fatigue/Sleep/Pain and Low Anxiety/Depression” (234 participants, 11%) had similar levels of fatigue, sleep disturbance, and pain as in the “High” class but low anxiety and depression symptoms. There were significant and substantive trends in sociodemographic characteristics (age, education, race or ethnicity, marital or partner status) and increasing disease severity (diffuse disease, tendon friction rubs, joint contractures, gastrointestinal symptoms) across severity-based classes. Disease severity and sociodemographic characteristics of “High Fatigue/Sleep/Pain and Low Anxiety/Depression” class participants were similar to the “High” severity class. Interpretation: Most people with systemic sclerosis can be classified by levels of patient-reported symptoms, which are consistent across symptoms and highly associated with sociodemographic and disease-related variables, except for one group which reports low mental health symptoms despite high levels of other symptoms and substantial disease burden. Studies are needed to better understand resilience in systemic sclerosis and to identify and facilitate implementation of cognitive and behavioural strategies to improve coping and overall quality of life. Funding: National Institute of Nursing Research (F31NR019007), Canadian Institutes of Health Research, Arthritis Society Canada, the Lady Davis Institute for Medical Research, the Jewish General Hospital Foundation, McGill University, Scleroderma Society of Ontario, Scleroderma Canada, Sclérodermie Québec, Scleroderma Manitoba, Scleroderma Atlantic, Scleroderma Association of BC, Scleroderma SASK, Scleroderma Australia, Scleroderma New South Wales, Scleroderma Victoria, and Scleroderma Queensland

Evaluation of Measurement Properties and Differential Item Functioning in the English and French Versions of the University of California, Los Angeles, Loneliness Scale-6: A Scleroderma Patient-Centered Intervention Network (SPIN) Study

Objective: Loneliness has been associated with poorer health-related quality of life but has not been studied in patients with systemic sclerosis (SSc). The current study was undertaken to examine and compare the psychometric properties of the English and French versions of the University of California, Los Angeles, Loneliness Scale-6 (ULS-6) in patients with SSc during the COVID-19 pandemic. Methods: This study used baseline cross-sectional data from 775 adults enrolled in the Scleroderma Patient-Centered Intervention Network (SPIN) COVID-19 Cohort. Reliability and validity of ULS-6 scores overall and between languages were evaluated using confirmatory factor analysis (CFA), differential item functioning (DIF) through the multiple-indicator multiple-cause (MIMIC) model, omega/alpha calculation, and correlations of hypothesized convergent relationships. Results: CFA for the total sample supported the single-factor structure (comparative fit index [CFI] 0.96, standardized root mean residual [SRMR] 0.03), and all standardized factor loadings for items were large (0.60–0.86). The overall MIMIC model with language as a covariate fit well (CFI 0.94, SRMR 0.04, root mean square error of approximation 0.11). Statistically significant DIF was found for 3 items across language (βitem2 = 0.14, P < 0.001; βitem4 = –0.07, P = 0.01; βitem6 = 0.13, P < 0.001), but these small differences were without practical measurement implications. Analyses demonstrated high internal consistency with no language-based convergent validity differences. Conclusion: Analyses demonstrated evidence of acceptable reliability and validity of ULS-6 scores in English- and French-speaking adults with SSc. DIF analysis supported use of the ULS-6 to examine comparative experiences of loneliness without adjusting for language

Pain levels and associated factors in the Scleroderma Patient-centered Intervention Network (SPIN) cohort: a multicentre cross-sectional study

Background: Pain is an important and detrimental feature of systemic sclerosis but is often overlooked or deprioritised in research and clinical care. Raynaud's phenomenon, arthritis, and cutaneous ulcers are among the commonly reported disease manifestations of systemic sclerosis that could be associated with pain. We aimed to assess levels of pain intensity and interference and to evaluate disease factors associated with pain intensity and interference. Methods: In this multicentre cross-sectional study, participants from the Scleroderma Patient-centered Intervention Network cohort who completed pain intensity and interference measures (Patient Reported Outcomes Information System-29 profile, version 2·0) as part of baseline assessments were included. Patients were recruited from 46 centres in Australia, Canada, France, Mexico, Spain, the UK, and the USA between April 15, 2014, and Jan 7, 2020. Eligible patients included those aged 18 years or older who met the criteria for systemic sclerosis devised by the American College of Rheumatology and the European League Against Rheumatism. Associations of pain intensity and pain interference with systemic sclerosis-related variables and overlap syndromes, controlling for sociodemographic variables, were assessed with multiple linear regression. Continuous independent variables were standardised. Findings: Among 2157 participants with systemic sclerosis (268 [12%] males and 1889 [88%] females), 1870 (87%) reported mild, moderate, or severe pain (defined as ≥1 on a 0 to 10 scale), and 815 (38%) reported moderate or severe pain (defined as ≥5). Moreover, 757 (35%) participants reported moderate or severe pain interference. Greater pain intensity was independently associated with female sex (0·58 points [95% CI 0·26–0·90]), non-White race or ethnicity (0·50 points [0·21–0·79]), fewer years in formal education (0·30 points per SD [0·19–0·41]), country (reference: USA; Canada: 0·29 points [0·01–0·57] and UK: 0·58 points [0·21–0·95]), greater body-mass index (0·35 points per SD [0·24–0·45]); joint contractures (0·67 points [0·39–0·94]), digital ulcers (0·33 points [0·10–0·55]), gastrointestinal involvement (0·66 points [0·33–0·98]), skin involvement (measured using modified Rodnan skin score; 0·22 points per SD [0·10–0·35]), rheumatoid arthritis (0·96 points [0·50–1·43]), and Sjögren's syndrome (0·42 points [0·01–0·83]). Pain interference results were similar. Interpretation: Pain is common among people with systemic sclerosis. Controlling for sociodemographic variables, greater pain was associated with multiple systemic sclerosis-related manifestations, including joint contractures, digital ulcers, gastrointestinal involvement, skin involvement, and the presence of overlap syndromes. Health-care providers should work with patients to address pain, including identifying and addressing systemic sclerosis manifestations associated with their pain, and supporting behavioural approaches to minimise impact on function and quality of life. Funding: Canadian Institutes of Health Research, Arthritis Society, The Lady Davis Institute for Medical Research of the Jewish General Hospital, Jewish General Hospital Foundation, McGill University, Scleroderma Society of Ontario, Scleroderma Canada, Sclérodermie Québec, Scleroderma Manitoba, Scleroderma Atlantic, Scleroderma Association of BC, Scleroderma SASK, Scleroderma Australia, Scleroderma New South Wales, Scleroderma Victoria, and Scleroderma Queensland

Rationale for the treatment of children with CCSK in the UMBRELLA SIOP-RTSG 2016 protocol

The International Society of Paediatric Oncology-Renal Tumour Study Group (SIOP-RTSG) has developed a new protocol for the diagnosis, treatment, and follow-up monitoring of childhood renal tumours-the UMBRELLA SIOP-RTSG 2016 protocol (the UMBRELLA protocol). This protocol has been designed to continue international collaboration in the treatment of childhood renal tumours and will be implemented in over 50 different countries. Clear cell sarcoma of the kidney, which is a rare paediatric renal tumour that most commonly occurs in childre