ABSTRACT
PURPOSE: To report the treatment utilization patterns for hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer in urban mainland China (CancerMPact®). METHODS: The results presented are from an online survey conducted in September 2019 with 45 physicians treating breast cancer patients from 11 cities in mainland China. RESULTS: Surveyed physicians reported that Stage I HR+/HER2(-) breast cancer patients are often treated with surgery alone (42%), whereas the use of surgery in combination with systemic therapy with or without radiotherapy increases in later stages (Stage II 67%, Stage III 77%). Doxorubicin-cyclophosphamide (AC)-based regimens were the most common in both the neoadjuvant and adjuvant settings in HR+/HER2(-) breast cancer patients, across all stages. In metastatic patients, use of surgery and radiotherapy decreases in favor of utilization of systemic therapy alone. Pre- and post-menopausal metastatic patients were frequently treated with hormone therapy or AC-based regimens in first line. Regardless of the first-line therapy administered, capecitabine-based regimens were commonly used in second line. In third line, chemotherapy regimens containing capecitabine or gemcitabine were given to nearly 40% of HR+/HER2(-) breast cancer patients. There were no standard of care regimens established for fourth or greater lines of treatment. In metastatic HR+/HER2(-) breast cancer, physicians reported 50% objective response rates in first-line settings with a progression-free survival of 16 months. CONCLUSION: HR+/HER2(-) breast cancer patients in urban mainland China were prescribed chemotherapy regimens more frequently than CDK4/6 inhibitors. Treatment practices varied, with physicians reporting the use of multiple modalities and treatment regimens for their patients.
Subject(s)
Breast Neoplasms , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/epidemiology , Capecitabine , China/epidemiology , Female , Humans , Neoadjuvant Therapy , Receptor, ErbB-2/metabolismABSTRACT
Subsets of high-grade gliomas, including glioblastoma (GBM), are known to utilize the alternative lengthening of telomeres (ALT) pathway for telomere length maintenance. However, the telomere maintenance profile of one subtype of GBM-giant cell GBM-has not been extensively studied. Here, we investigated the prevalence of ALT, as well as ATRX and SMARCAL1 protein loss, in a cohort of classic giant cell GBM and GBM with giant cell features. To determine the presence of ALT, a telomere-specific fluorescence in situ hybridization assay was performed on 15 cases of classic giant cell GBM, 28 additional GBMs found to have giant cell features, and 1 anaplastic astrocytoma with giant cell features. ATRX, SMARCAL1, and IDH1 protein status were assessed in a proportion of cases by immunohistochemistry and were compared to clinical-pathologic and molecular characteristics. In the overall cohort of 44 cases, 19 (43%) showed evidence of ALT. Intriguingly, of the ALT-positive cases, only 9 (47.4%) displayed loss of the ALT suppressor ATRX by immunohistochemistry. Since inactivating mutations in SMARCAL1 have been identified in ATRX wild-type ALT-positive gliomas, we developed an immunohistochemistry assay for SMARCAL1 protein expression using genetically validated controls. Of the 19 ALT-positive cases, 6 (31.5%) showed loss or mis-localization of SMARCAL1 by immunohistochemistry. Of these cases, four retained ATRX protein expression, while two cases also displayed ATRX loss. Additionally, we assessed five cases from which multiple temporal samples were available and ALT status was concordant between both tumor biopsies. In summary, we have identified a subset of giant cell GBM that utilize the ALT telomere maintenance mechanism. Importantly, in addition to ATRX loss, ALT-positive tumors harboring SMARCAL1 alterations are prevalent in giant cell GBM.
Subject(s)
Brain Neoplasms/metabolism , DNA Helicases/metabolism , Glioblastoma/metabolism , Telomere Homeostasis/genetics , Adolescent , Adult , Aged , Biopsy , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Child, Preschool , DNA Helicases/genetics , Female , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Isocitrate Dehydrogenase/genetics , Isocitrate Dehydrogenase/metabolism , Male , Middle Aged , Mutation , X-linked Nuclear Protein/genetics , X-linked Nuclear Protein/metabolism , Young AdultABSTRACT
OBJECTIVE: To examine political participation after traumatic brain injury (TBI). DESIGN: Qualitative, participatory research via interviews and observations. Each participant was interviewed to discuss their experience of voting in 2007 or 2008. Data were coded using Grounded Theory to develop themes, metacodes, and theories. SETTING: Community. PARTICIPANTS: A total of 57 individuals with history of TBI and 28 family members (N=85). MAIN OUTCOME MEASURES: Not applicable. RESULTS: Four themes emerged from the data: (1) people with TBI have barriers to voting; (2) the voting process can be improved for people with TBI; (3) voting is the responsibility of members of society; and (4) voting is one way we have a voice in society. CONCLUSIONS: The data support the importance of voting as an American right regardless of the presence of disability. While persons with TBI report voting represents their freedom and voice, there may be barriers that can threaten or limit their voice.
Subject(s)
Brain Injuries, Traumatic/psychology , Disabled Persons/psychology , Empowerment , Family/psychology , Politics , Adult , Community-Based Participatory Research , Female , Grounded Theory , Humans , Male , Middle Aged , North Carolina , Qualitative ResearchABSTRACT
Telomeres are nucleoprotein complexes located at the termini of eukaryotic chromosomes that prevent exonucleolytic degradation and end-to-end chromosomal fusions. Cancers often have critically shortened, dysfunctional telomeres contributing to genomic instability. Telomere shortening has been reported in a wide range of precancerous lesions and invasive carcinomas. However, the role of telomere alterations, including the presence of alternative lengthening of telomeres (ALT), has not been studied in pituitary adenomas. Telomere length and the presence of ALT were assessed directly at the single cell level using a telomere-specific fluorescence in situ hybridization assay in tissue microarrays. Tumors were characterized as either ALT-positive or having short, normal, or long telomere lengths and then these categories were compared with clinicopathological characteristics. ATRX and DAXX expression was studied through immunohistochemistry. We characterized a discovery set of 106 pituitary adenomas including both functional and nonfunctional subsets (88 primary, 18 recurrent). Telomere lengths were estimated and we observed 64 (59.4%) cases with short, 39 (36.8%) cases with normal, and 0 (0%) cases with long telomeres. We did not observe significant differences in the clinicopathological characteristics of the group with abnormally shortened telomeres compared to the group with normal telomeres. However, three pituitary adenomas were identified as ALT-positive of which two were recurrent tumors. Two of these three ALT-positive cases had alterations in either of the chromatin remodeling proteins, ATRX and DAXX, which are routinely altered in other ALT-positive tumor subtypes. In a second cohort of 32 recurrent pituitary adenomas from 22 patients, we found that the tumors from 36% of patients (n = 8) were ALT-positive. This study demonstrates that short telomere lengths are prevalent in pituitary adenomas and that ALT-positive pituitary adenomas are enriched in recurrent disease.
Subject(s)
Adenoma/genetics , Co-Repressor Proteins/biosynthesis , Molecular Chaperones/biosynthesis , Pituitary Neoplasms/genetics , Telomere/metabolism , X-linked Nuclear Protein/biosynthesis , Adenoma/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Pituitary Neoplasms/pathology , Telomere Homeostasis/physiology , Young AdultABSTRACT
Aim: To report the results of a survey of USA physicians (CancerMPact) that treat non-small-cell lung cancer patients. Materials & methods: 60 physicians were surveyed. Questions covered aspects of the treatment for all stages of the disease. Results: For stage I patients, over 70% of the treatments were based on surgery. For stage II/III disease, a strong preference for combined therapy (surgery/radiation/systemic therapy) was observed. For advanced/stage IV patients, physicians used systemic therapy alone, and choosed the regimen based on histology and biomarkers. Use of PD-L1 inhibitors was highly dependent on histology and biomarkers. Conclusion: The treatment choices of non-small-cell lung cancer are increasingly complex, involve different treatment modalities and are highly dependent on histology and biomarkers, besides stage.
Subject(s)
Carcinoma, Non-Small-Cell Lung/epidemiology , Carcinoma, Non-Small-Cell Lung/therapy , Lung Neoplasms/epidemiology , Lung Neoplasms/therapy , Oncologists , Practice Patterns, Physicians' , Radiation Oncologists , Biomarkers, Tumor , Carcinoma, Non-Small-Cell Lung/diagnosis , Carcinoma, Non-Small-Cell Lung/etiology , Clinical Competence , Combined Modality Therapy , Disease Management , Disease Susceptibility , Health Care Surveys , Humans , Lung Neoplasms/diagnosis , Lung Neoplasms/mortality , Mutation , Neoplasm Staging , PhysiciansABSTRACT
The death of a child creates especially poignant feelings and extreme stress, distress, and devastation for family members and healthcare providers. In addition, serious or long-term illness forces a reconstruction of our experiences with time and space. In this paper, we report on a long-term ethnographic study of a Pediatric Palliative Care Team (PPCT). Using the concepts of spatiality and temporality; Deleuze's concepts of smooth and striated spaces; Innis's concepts of space and time biases; Foucault's concept of heterotopian space-places with multiple layers of meaning; and a related concept of heterokairoi-moments in time with multiple possibilities-we consider how the PPCT constructs and reconstructs meaning in the midst of chaos, ethical dilemmas, and heartbreaking choices.
Subject(s)
Attitude to Death , Palliative Care , Patient Care Team , Pediatrics , Anthropology, Cultural , Child , Communication , Death , Hospitals, Pediatric , Humans , Parents/psychology , Spatial Analysis , Time Factors , UncertaintyABSTRACT
BACKGROUND: Trastuzumab targets the human epidermal growth factor receptor-2 (HER2). Cardiotoxicity is a potential adverse effect, manifesting as either an asymptomatic decline in left-ventricular ejection fraction or infrequently as largely reversible symptomatic heart failure (HF). Monitoring recommendations differ between product labeling and 2012 guidelines, and the clinical utility of serial cardiac monitoring in patients with metastatic breast cancer remains controversial. OBJECTIVE: The objectives of this study were to describe the frequency of monitoring, incidence of symptomatic or asymptomatic HF, overall effect on treatment, and cost of monitoring for cardiotoxicity. METHODS: We preformed an institutional review board-approved retrospective chart review of breast cancer patients receiving trastuzumab from January 1, 2009, through January 1, 2014, at an academic medical center. RESULTS: Out of 154 treatments, 72% were adjuvant, and 28% were metastatic. In the adjuvant setting, a mean of 4.5 (interquartile range [IQR] = 4-5) echocardiograms (echos) over a mean of 11.5 (IQR = 11-12) months were performed. In the metastatic setting, a mean of 3.1 (IQR = 1-5) echos over a mean of 20.2 (IQR = 9-31) months were performed. Symptomatic HF events occurred in 4 adjuvant (3.6%) and 2 metastatic patients (6.5%); 10 patients (6.5%) had a treatment interruption, with 9 (90%) tolerating restart of trastuzumab. Two patients (1.3%) changed treatment as a result of cardiotoxicity. Using population incidence of HER2-positive breast cancer, $13 million could be saved if monitoring were reduced by 1 echo per patient. CONCLUSIONS: Given the low incidence of clinically significant HF and cost of monitoring, less frequent monitoring may be justified.
Subject(s)
Antineoplastic Agents/adverse effects , Breast Neoplasms/drug therapy , Drug Monitoring/methods , Heart Failure/chemically induced , Trastuzumab/adverse effects , Adult , Aged , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/therapeutic use , Cardiotoxicity , Drug Monitoring/standards , Female , Humans , Middle Aged , Receptor, ErbB-2/antagonists & inhibitors , Retrospective Studies , Trastuzumab/administration & dosage , Trastuzumab/therapeutic use , Ventricular Function, Left/drug effectsABSTRACT
BACKGROUND: Individuals with a history of traumatic brain injury (TBI) may have chronic problems with irritability, which can negatively affect their lives. OBJECTIVES: (1) To describe the experience (thoughts and feelings) of irritability from the perspectives of multiple people living with or affected by the problem, and (2) to develop a conceptual model of irritability. DESIGN: Qualitative, participatory research. PARTICIPANTS: Forty-four stakeholders (individuals with a history of TBI, family members, community professionals, healthcare providers, and researchers) divided into 5 focus groups. PROCEDURES: Each group met 10 times to discuss the experience of irritability following TBI. Data were coded using grounded theory to develop themes, metacodes, and theories. MEASURES: Not applicable. RESULTS: A conceptual model emerged in which irritability has 5 dimensions: affective (related to moods and feelings); behavioral (especially in areas of self-regulation, impulse control, and time management); cognitive-perceptual (self-talk and ways of seeing the world); relational issues (interpersonal and family dynamics); and environmental (including environmental stimuli, change, disruptions in routine, and cultural expectations). CONCLUSIONS: This multidimensional model provides a framework for assessment, treatment, and future research aimed at better understanding irritability, as well as the development of assessment tools and treatment interventions.
Subject(s)
Brain Injuries, Traumatic/psychology , Irritable Mood , Adaptation, Psychological , Adolescent , Adult , Aged , Case-Control Studies , Family , Female , Focus Groups , Grounded Theory , Humans , Male , Middle Aged , Models, Theoretical , Qualitative Research , Young AdultABSTRACT
Eulogies serve a sensemaking function of identity construction--both for the deceased and for the survivors. This work examines the communicative construction of identity in eulogies and shows how eulogia discourse affirms and reconstructs our relational identity through communication. The article extends scholarship on eulogies by using relational communication theories to investigate how eulogic discourse functions as identity construction, considering eulogies of ordinary people, and exploring the gendered nature of eulogies. We discuss how eulogies are specific ritualized forms of communication in which the bereaved focus on self-identity as they articulate their experience of grief.
Subject(s)
Adaptation, Psychological/physiology , Ceremonial Behavior , Death , Funeral Rites/psychology , Grief , Social Support , Attitude to Death , Humans , Survivors/psychologyABSTRACT
Siltuximab is a chimeric monoclonal antibody targeting interleukin-6 (IL-6), which in the fall of 2014 became the first FDA-approved treatment of the rare disease idiopathic multicentric Castleman's disease (MCD). MCD is a non-clonal lymphoproliferative disorder in which common symptoms include fever, night sweats, weight loss, and fatigue. Symptoms are driven by an overall hypercytokinemia, predominantly IL-6. While under clinical development, siltuximab was studied in several other disease states including multiple myeloma, non-Hodgkin lymphomas, and several solid tumors in which it did not demonstrate significant benefit. The efficacy of siltuximab in MCD is mainly confined to systemic symptomatic response and quality of life benefits with minimal complete responses and approximately 30 % partial responses, by radiographic criteria. Siltuximab treatment therefore is important in the overall treatment of this rare disease state. This review focuses on the clinical development and pharmaceutical approval of siltuximab.
Subject(s)
Antibodies, Monoclonal/pharmacology , Antibodies, Monoclonal/pharmacokinetics , Antineoplastic Agents/pharmacology , Antineoplastic Agents/pharmacokinetics , Castleman Disease/drug therapy , Interleukin-6/antagonists & inhibitors , Multiple Myeloma/drug therapy , Animals , Antibodies, Monoclonal/administration & dosage , Antineoplastic Agents/administration & dosage , Clinical Trials, Phase I as Topic , Clinical Trials, Phase II as Topic , Drug Approval , Drug Evaluation, Preclinical , Humans , Treatment OutcomeABSTRACT
BACKGROUND: A functional polymorphism (5-HTTLPR) in the promoter region of the serotonin transporter gene has been widely studied as a risk factor and moderator of treatment for a variety of psychopathologic conditions. To evaluate whether 5-HTTLPR moderates the effects of treatment to reduce heavy drinking, we studied 112 high-functioning European-American men who have sex with men (MSM). Subjects participated in a randomized clinical trial of naltrexone (NTX) and cognitive behavioral therapy (CBT) for problem drinking. METHODS: Subjects were treated for 12 weeks with 100 mg/d of oral NTX or placebo (PBO). All participants received medical management with adjusted brief behavioral compliance enhancement treatment (BBCET) alone or in combination with modified behavioral self-control therapy (MBSCT; an amalgam of motivational interviewing and CBT). Participants were genotyped for the tri-allelic 5-HTTLPR polymorphism (i.e., low-activity S' or high-activity L' alleles). RESULTS: During treatment, the number of weekly heavy drinking days (HDD; defined as 5 or more standard drinks per day) was significantly lower in subjects with the L'L' (N = 26, p = 0.015) or L'S' (N = 52, p = 0.016) genotype than those with the S'S' (N = 34) genotype regardless of treatment type. There was a significant interaction of genotype with treatment: For subjects with the S'S' genotype, the effects of MBSCT or NTX on HDD were significantly greater than the minimal intervention (i.e., BBCET or PBO, p = 0.007 and p = 0.049, respectively). In contrast, for subjects with 1 or 2 L' alleles, the effects of the more intensive psychosocial treatment (MBSCT) or NTX did not significantly differ from BBCET or PBO. CONCLUSIONS: These preliminary findings support the utility of the 5-HTTLPR polymorphism for personalizing treatment selection in problem drinkers.
Subject(s)
Alcoholism/genetics , Alcoholism/therapy , Cognitive Behavioral Therapy , Homosexuality, Male/genetics , Naltrexone/therapeutic use , Polymorphism, Genetic/genetics , Serotonin Plasma Membrane Transport Proteins/genetics , Adult , Alcoholism/psychology , Cognitive Behavioral Therapy/methods , Humans , Male , Middle Aged , Treatment OutcomeABSTRACT
This is a case of nontraumatic shoulder pain initially diagnosed on x-ray as an anterior dislocation. The patient was on anticoagulants and, in actuality, had severe hemarthrosis that caused the subluxation. Attempts to reduce the dislocation in this situation might have resulted in worsening of the intra-articular bleed. There has been only 1 similar reported case in the European Journal of Emergency Medicine in 2013 of a 53-year-old woman who was thought to have a nontraumatic anterior shoulder dislocation, and attempts were unsuccessful at reduction. Definitive therapy involved hemarthrosis aspiration. Others have reported spontaneous hemarthrosis due to anticoagulants; however, only 1 has reported an initial mistaken joint dislocation diagnosis. Nontraumatic hemarthrosis do occur in patients on anticoagulant therapy, and it is important to recognize that this can be misdiagnosed as a joint dislocation requiring reduction. In a patient who is on anticoagulants presenting with nontraumatic joint pain and anterior shoulder or possibly other dislocations on plain radiographs, it is pertinent to consider hemarthrosis.
Subject(s)
Anticoagulants/adverse effects , Hemarthrosis/chemically induced , Shoulder Dislocation/diagnosis , Emergency Service, Hospital , Female , Hemarthrosis/complications , Hemarthrosis/diagnosis , Hemarthrosis/diagnostic imaging , Humans , Middle Aged , Radiography , Shoulder Dislocation/diagnostic imaging , Shoulder Joint/diagnostic imaging , Shoulder Pain/etiologyABSTRACT
UNLABELLED: Personalized feedback (PF) has demonstrated effectiveness in reducing drinking. Few studies have examined its effectiveness with adult problem drinkers or its potential mediators or moderators, including developing discrepancy. This study aimed to identify potential mediators and moderators of PF provided to adult problem drinking men who have sex with men (PDMSM). METHOD: An exploratory analysis of PF provided to PDMSM in the context of modified behavioral self-control therapy (N = 90). The association of individual items of PF, severity of PF, and independently rated, in-session participant reactions to PF with drinking outcomes (mean drinks per drinking day, MDDD) were examined using correlations and logistic and linear regression. RESULTS: Significant pre-post differences in MDDD emerged. Other drug risk, family risk, and having an abnormal liver enzyme test result were significantly associated with proxies for developed discrepancy in expected directions; however, no PF item or reaction to PF predicted drinking outcomes. Severity of PF was not associated with participant reactions or drinking outcome. CONCLUSIONS: PF may be an effective intervention for PDMSM. Further research is needed to identify potential mediators and moderators of PF among adults.
Subject(s)
Alcoholism/psychology , Feedback , Homosexuality, Male/psychology , Adolescent , Adult , Aged , Humans , Male , Middle Aged , Regression Analysis , Videotape Recording , Young AdultABSTRACT
OBJECTIVE: Assessment reactivity research has contributed substantially to our understanding of alcohol treatment research protocols influencing clinical outcomes. The state of the science is such that relatively little is known about how alcohol treatment research participation influences behavior. The purpose of this study was twofold: (a) to determine the distribution of FRAMES elements (i.e., Feedback, personal Responsibility, Advice, a Menu of options, Empathic style of interaction, and support for Self-efficacy) contained in alcohol treatment research assessment interviews; and (b) to examine their association with subsequent alcohol use among a sample of clients presenting for alcohol use disorder treatment. METHOD: Audiotaped recordings of participant (n = 189) research assessment interviews were converted to digital recordings and reviewed for FRAMES elements using the FRAMES Checklist Instrument. RESULTS: Feedback, personal responsibility, empathic style of interaction, and support for self-efficacy were the more frequently occurring elements across follow-up periods. Alternatively, menu of options and advice occurred infrequently. Feedback and support for self-efficacy predicted subsequent alcohol use, although the association between feedback and alcohol use was unexpectedly positive. CONCLUSIONS: As part of the assessment interview process, alcohol treatment research participants receive multiple instances of feedback and support for self-efficacy specific to their alcohol use that are predictive of changes in alcohol use.
Subject(s)
Alcoholism , Humans , Alcoholism/epidemiology , Alcoholism/therapy , Alcohol Drinking/epidemiology , Social Behavior , Self Efficacy , FeedbackABSTRACT
BACKGROUND: Hospital medicine (HM) continues to be primarily composed of junior hospitalists and research has highlighted a paucity of mentors and academic output. Faculty advancement programs have been identified as a means to support junior hospitalists in their career trajectories and to advance the field. The optimal approach to supporting faculty development (FD) efforts is not known. OBJECTIVE: To understand hospitalist groups' approaches to FD, including efforts that were perceived to be effective, and to identify barriers as well as potential future directions for FD. DESIGN: Rapid qualitative methods were utilized including templated summaries and matrix analysis to identify major themes. SETTING AND PARTICIPANTS: Virtual focus groups with hospitalists in the Hospital Medicine Reengineering Network (HOMERuN). MAIN OUTCOME AND MEASURES: Qualitative themes. RESULTS: Nineteen individuals from 17 unique institutions from across the United States in May 2022 participated in seven focus groups. Four key themes emerged from the study and included (1) academic hospitalist programs face multifaceted challenges and barriers to FD in HM, (2) groups have embraced a diversity of structures and frameworks, (3) due to clinical volumes, FD programs have had to adapt and evolve to meet FD needs, and (4) participants identified multiple areas for improvement, including defining tangible outcomes of FD programs and creating a repository of FD material which can be shared widely.
Subject(s)
Faculty, Medical , Focus Groups , Hospital Medicine , Hospitalists , Qualitative Research , Staff Development , Humans , Hospital Medicine/education , United States , Mentors , Male , Female , Academic Medical CentersABSTRACT
BACKGROUND: Intraperitoneal (IP) aminoglycosides (AGs) continue to be the cornerstone of empiric management of peritonitis. AG dosing during automated peritoneal dialysis (APD), however, has not been well studied in patients with peritonitis. We sought to identify differences in AG exposure in the peritoneum and plasma for two different dosing regimens with little supporting evidence in patients on APD with peritonitis. METHODS: A retrospective design that utilised the peritoneal and plasma concentration-time data from a prior study of 18 continuous ambulatory peritoneal dialysis (CAPD) patients with peritonitis to generate an in silico peritoneal and plasma PK model. This model was then used to compare via simulation using Phoenix© WinNonlin Software with IP AG dosing for a loading-dose regimen (1.5 mg/kg first dose) versus a fixed-dose regimen (0.6 mg/kg/d) in patients on APD with peritonitis. RESULTS: Outcome measures were (1) percentage of time where peritoneal peak concentrations/minimal inhibitory concentration (MIC) ratio >10, (2) AUC/MIC > 74 and (3) plasma Cmin concentrations. Both regimens resulted in > 90% optimal peak/MIC ratio and AUC/MIC ratios on days 1 and 5 of the dose protocol. The loading-dose regimen resulted in IP exposures that were 2.5 times greater in the peritoneal compartment on day 1. By day 5, both protocols resulted in similar accumulation of AG plasma Cmin concentrations of 2.5-3.4 mg/L versus 2.4-3.3 mg/L, respectively, for the loading-dose regimen versus fixed-dose regimen. CONCLUSIONS: The current international guidelines for the treatment of peritoneal dialysis-associated peritonitis can continue to recommend the fixed-dose regimen for those on APD with the addition of plasma Cmin monitoring after 3 days to assess for drug accumulation.
ABSTRACT
Acquiring a telomere maintenance mechanism is a hallmark of high-risk neuroblastoma and commonly occurs by expressing telomerase (TERT). Telomerase-negative neuroblastoma has long telomeres and utilizes the telomerase-independent alternative lengthening of telomeres (ALT) mechanism. Conversely, no discernable telomere maintenance mechanism is detected in a fraction of neuroblastoma with long telomeres. Here, we show, unlike most cancers, DNA of the TERT promoter is broadly hypomethylated in neuroblastoma. In telomerase-positive neuroblastoma cells, the hypomethylated DNA promoter is approximately 1.5 kb. The TERT locus shows active chromatin marks with low enrichment for the repressive mark, H3K27me3. MYCN, a commonly amplified oncogene in neuroblstoma, binds to the promoter and induces TERT expression. Strikingly, in neuroblastoma with long telomeres, the hypomethylated region spans the entire TERT locus, including multiple nearby genes with enrichment for the repressive H3K27me3 chromatin mark. Furthermore, subtelomeric regions showed enrichment of repressive chromatin marks in neuroblastomas with long telomeres relative to those with short telomeres. These repressive marks were even more evident at the genic loci, suggesting a telomere position effect (TPE). Inhibiting H3K27 methylation by three different EZH2 inhibitors induced the expression of TERT in cell lines with long telomeres and H3K27me3 marks in the promoter region. EZH2 inhibition facilitated MYCN binding to the TERT promoter in neuroblastoma cells with long telomeres. Taken together, these data suggest that epigenetic regulation of TERT expression differs in neuroblastoma depending on the telomere maintenance status, and H3K27 methylation is important in repressing TERT expression in neuroblastoma with long telomeres. SIGNIFICANCE: The epigenetic landscape of the TERT locus is unique in neuroblastoma. The DNA at the TERT locus, unlike other cancer cells and similar to normal cells, are hypomethylated in telomerase-positive neuroblastoma cells. The TERT locus is repressed by polycomb repressive complex-2 complex in neuroblastoma cells that have long telomeres and do not express TERT. Long telomeres in neuroblastoma cells are also associated with repressive chromatin states at the chromosomal termini, suggesting TPE.
Subject(s)
Neuroblastoma , Promoter Regions, Genetic , Telomerase , Telomere , Neuroblastoma/genetics , Neuroblastoma/pathology , Neuroblastoma/metabolism , Telomerase/genetics , Telomerase/metabolism , Humans , Promoter Regions, Genetic/genetics , Telomere/metabolism , Telomere/genetics , Cell Line, Tumor , DNA Methylation/genetics , N-Myc Proto-Oncogene Protein/genetics , N-Myc Proto-Oncogene Protein/metabolism , Gene Expression Regulation, Neoplastic , Polycomb-Group Proteins/genetics , Polycomb-Group Proteins/metabolismABSTRACT
Modifications to vaccine delivery that increase serum antibody longevity are of great interest for maximizing efficacy. We have previously shown that a delayed fractional (DFx) dosing schedule (0-1-6 month) - using AS01B-adjuvanted RH5.1 malaria antigen - substantially improves serum IgG durability as compared with monthly dosing (0-1-2 month; NCT02927145). However, the underlying mechanism and whether there are wider immunological changes with DFx dosing were unclear. Here, PfRH5-specific Ig and B cell responses were analyzed in depth through standardized ELISAs, flow cytometry, systems serology, and single-cell RNA-Seq (scRNA-Seq). Data indicate that DFx dosing increases the magnitude and durability of circulating PfRH5-specific B cells and serum IgG1. At the peak antibody magnitude, DFx dosing was distinguished by a systems serology feature set comprising increased FcRn binding, IgG avidity, and proportion of G2B and G2S2F IgG Fc glycans, alongside decreased IgG3, antibody-dependent complement deposition, and proportion of G1S1F IgG Fc glycan. Concomitantly, scRNA-Seq data show a higher CDR3 percentage of mutation from germline and decreased plasma cell gene expression in circulating PfRH5-specific B cells. Our data, therefore, reveal a profound impact of DFx dosing on the humoral response and suggest plausible mechanisms that could enhance antibody longevity, including improved FcRn binding by serum Ig and a potential shift in the underlying cellular response from circulating short-lived plasma cells to nonperipheral long-lived plasma cells.