Identification of Immunogenic MHC Class II Human HER3 Peptides that Mediate Anti-HER3 CD4+ Th1 Responses and Potential Use as a Cancer Vaccine.

The HER3/ERBB3 receptor is an oncogenic receptor tyrosine kinase that forms heterodimers with EGFR family members and is overexpressed in numerous cancers. HER3 overexpression associates with reduced survival and acquired resistance to targeted therapies, making it a potential therapeutic target in multiple cancer types. Here, we report on immunogenic, promiscuous MHC class II-binding HER3 peptides, which can generate HER3-specific CD4+ Th1 antitumor immune responses. Using an overlapping peptide screening methodology, we identified nine MHC class II-binding HER3 epitopes that elicited specific Th1 immune response in both healthy donors and breast cancer patients. Most of these peptides were not identified by current binding algorithms. Homology assessment of amino acid sequence BLAST showed >90% sequence similarity between human and murine HER3/ERBB3 peptide sequences. HER3 peptide-pulsed dendritic cell vaccination resulted in anti-HER3 CD4+ Th1 responses that prevented tumor development, significantly delayed tumor growth in prevention models, and caused regression in multiple therapeutic models of HER3-expressing murine tumors, including mammary carcinoma and melanoma. Tumors were robustly infiltrated with CD4+ T cells, suggesting their key role in tumor rejection. Our data demonstrate that class II HER3 promiscuous peptides are effective at inducing HER3-specific CD4+ Th1 responses and suggest their applicability in immunotherapies for human HER3-overexpressing tumors.

Effect of Pembrolizumab Plus Neoadjuvant Chemotherapy on Pathologic Complete Response in Women With Early-Stage Breast Cancer: An Analysis of the Ongoing Phase 2 Adaptively Randomized I-SPY2 Trial.

Importance: Approximately 25% of patients with early-stage breast cancer who receive (neo)adjuvant chemotherapy experience a recurrence within 5 years. Improvements in therapy are greatly needed. Objective: To determine if pembrolizumab plus neoadjuvant chemotherapy (NACT) in early-stage breast cancer is likely to be successful in a 300-patient, confirmatory randomized phase 3 neoadjuvant clinical trial. Design, Setting, and Participants: The I-SPY2 study is an ongoing open-label, multicenter, adaptively randomized phase 2 platform trial for high-risk, stage II/III breast cancer, evaluating multiple investigational arms in parallel. Standard NACT serves as the common control arm; investigational agent(s) are added to this backbone. Patients with ERBB2 (formerly HER2)-negative breast cancer were eligible for randomization to pembrolizumab between November 2015 and November 2016. Interventions: Participants were randomized to receive taxane- and anthracycline-based NACT with or without pembrolizumab, followed by definitive surgery. Main Outcomes and Measures: The primary end point was pathologic complete response (pCR). Secondary end points were residual cancer burden (RCB) and 3-year event-free and distant recurrence-free survival. Investigational arms graduated when demonstrating an 85% predictive probability of success in a hypothetical confirmatory phase 3 trial. Results: Of the 250 women included in the final analysis, 181 were randomized to the standard NACT control group (median [range] age, 47 [24.77] years). Sixty-nine women (median [range] age, 50 [27-71] years) were randomized to 4 cycles of pembrolizumab in combination with weekly paclitaxel followed by AC; 40 hormone receptor (HR)-positive and 29 triple-negative. Pembrolizumab graduated in all 3 biomarker signatures studied. Final estimated pCR rates, evaluated in March 2017, were 44% vs 17%, 30% vs 13%, and 60% vs 22% for pembrolizumab vs control in the ERBB2-negative, HR-positive/ERBB2-negative, and triple-negative cohorts, respectively. Pembrolizumab shifted the RCB distribution to a lower disease burden for each cohort evaluated. Adverse events included immune-related endocrinopathies, notably thyroid abnormalities (13.0%) and adrenal insufficiency (8.7%). Achieving a pCR appeared predictive of long-term outcome, where patients with pCR following pembrolizumab plus chemotherapy had high event-free survival rates (93% at 3 years with 2.8 years' median follow-up). Conclusions and Relevance: When added to standard neoadjuvant chemotherapy, pembrolizumab more than doubled the estimated pCR rates for both HR-positive/ERBB2-negative and triple-negative breast cancer, indicating that checkpoint blockade in women with early-stage, high-risk, ERBB2-negative breast cancer is highly likely to succeed in a phase 3 trial. Pembrolizumab was the first of 10 agents to graduate in the HR-positive/ERBB2-negative signature. Trial Registration: ClinicalTrials.gov Identifier: NCT01042379.

Strategies to Combat Human Epidermal Growth Factor Receptor 2 (HER2) Resistance in HER2-Positive Breast Cancer.

The discovery of human epidermal growth factor receptor 2 (HER2) and its role in breast cancer led to the development of the first targeted antibody treatment for HER2-positive breast cancer. This treatment breakthrough led to remarkable improvements in both early and late survival. Unfortunately, not all patients with HER2 breast cancer responded positively; some have innate resistance to treatment and others develop resistance over time. In this review, we discuss some research that is currently underway to understand HER2 resistance and strategies in overcoming it.

Navigating identity: Experiences of binary and non-binary transgender and gender non-conforming (TGNC) adults.

Background: Emerging research and colloquial dialogues increasingly point to an uptick in non-binary gender identity endorsement, however research has failed to parallel this increase. For example, existing literature often conflates gender identity with sexual orientation, lumping TGNC people under the LGBTQ umbrella, thus rendering the "T" silent in the process. Further, extant research adheres to a binary (i.e., dichotomous male/female) conceptualization of gender, thus excluding individuals who identify as genderqueer, gender non-conforming, or otherwise non-binary as well as those who do not identify with the construct of gender at all (e.g., agender). Method: This qualitative investigation utilized individual interviews with 15 TGNC adults. Data analysis employed two data-driven phases, first identifying themes consistent across the 15 transcripts to identify nuances in TGNC identity formation often missed by theory-driven models and second, establishing similarities and differences between binary and non-binary narratives. Results: Results indicated that various helpful and challenging factors played a stronger role than chronology, physical transition, or activism across all participants which contrasts findings in extant literature. Further, while binary and non-binary narratives were similar in many regards, several noteworthy distinctions emerged. For example, the concepts of "passing or blending", intersections of gender identity with sexual orientation, and navigating identity presentation and disclosure were described differently for binary and non-binary participants. Conclusions: Historically, the "T" in "LGBTQ" has often been rendered silent. These results indicate that non-binary narratives have been rendered doubly silent. Given the increasing preponderance of non-binary identifications and the unique needs and experiences of non-binary participants, it is crucial that professional and lay communities alike begin to take two steps moving forward: 1) explicitly acknowledge the existence of non-binary TGNC identities and 2) work to achieve fluency regarding the unique needs and experiences of this population.

Personalizing Radiation Treatment Delivery in the Management of Breast Cancer.

Long-term data establishes the efficacy of radiotherapy in the adjuvant management of breast cancer. New dose and fractionation schemas have evolved and are available, each with unique risks and rewards. Current efforts are ongoing to tailor radiotherapy to the unique biology of breast cancer. In this review, we discuss our efforts to personalize radiotherapy dosing using genomic data and the implications for future clinical trials. We also explore immune mechanisms that may contribute to a tumor's unique radiation sensitivity or resistance.

Intrathecal trastuzumab in the management of HER2+ breast leptomeningeal disease: a single institution experience.

PURPOSE: Leptomeningeal disease is a rare and devastating presentation of advanced stage metastatic breast cancer with historically poor overall survival. We assessed the safety and feasibility of intrathecal (IT) trastuzumab in HER2+ leptomeningeal disease. METHODS: A total of 13 patients were treated at our institution with IT trastuzumab beginning November 2012 and followed until November 2017. Outcomes including craniospinal progression as well as overall survival (OS) following initiation of IT trastuzumab were assessed from review of the clinical chart and radiologic examinations. RESULTS: The median age of patients was 48 (range 29-75). Median time from breast cancer diagnosis to development of brain metastases was 87.7 months with a median of 4.6 months from brain metastases diagnosis to the development of leptomeningeal disease. Previous whole brain radiotherapy was received by the majority of patients (92%) and prior surgery for brain metastases was performed in 23%. Median duration of IT trastuzumab treatment was 6.4 months. Median time from IT trastuzumab start to craniospinal progression was 5.7 months with 6- and 12-month Kaplan-Meier rates of 41 and 21%, respectively. Sustained responses > 6 months were achieved in 4 patients. Median survival from the start of IT trastuzumab was 10.6 months with 6- and 12-month OS rates of 68 and 47%, respectively. IT trastuzumab was well tolerated with one patient developing ventriculitis, which resolved with IV antibiotics. CONCLUSIONS: IT trastuzumab was well tolerated with prolongation of OS over historical controls. IT trastuzumab should be considered for management of HER2+ leptomeningeal disease patients.

Cryptic exon incorporation occurs in Alzheimer's brain lacking TDP-43 inclusion but exhibiting nuclear clearance of TDP-43.

Abnormal accumulation of TDP-43 into cytoplasmic or nuclear inclusions with accompanying nuclear clearance, a common pathology initially identified in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), has also been found in Alzheimer' disease (AD). TDP-43 serves as a splicing repressor of nonconserved cryptic exons and that such function is compromised in brains of ALS and FTD patients, suggesting that nuclear clearance of TDP-43 underlies its inability to repress cryptic exons. However, whether TDP-43 cytoplasmic aggregates are a prerequisite for the incorporation of cryptic exons is not known. Here, we assessed hippocampal tissues from 34 human postmortem brains including cases with confirmed diagnosis of AD neuropathologic changes along with age-matched controls. We found that cryptic exon incorporation occurred in all AD cases exhibiting TDP-43 pathology. Furthermore, incorporation of cryptic exons was observed in the hippocampus when TDP-43 inclusions was restricted only to the amygdala, the earliest stage of TDP-43 progression. Importantly, cryptic exon incorporation could be detected in AD brains lacking TDP-43 inclusion but exhibiting nuclear clearance of TDP-43. These data supports the notion that the functional consequence of nuclear depletion of TDP-43 as determined by cryptic exon incorporation likely occurs as an early event of TDP-43 proteinopathy and may have greater contribution to the pathogenesis of AD than currently appreciated. Early detection and effective repression of cryptic exons in AD patients may offer important diagnostic and therapeutic implications for this devastating illness of the elderly.

Mindfulness-Based Stress Reduction in Post-treatment Breast Cancer Patients: Immediate and Sustained Effects Across Multiple Symptom Clusters.

CONTEXT: Breast cancer survivors (BCS) face adverse physical and psychological symptoms, often co-occurring. Biologic and psychological factors may link symptoms within clusters, distinguishable by prevalence and/or severity. Few studies have examined the effects of behavioral interventions or treatment of symptom clusters. OBJECTIVES: The aim of this study was to identify symptom clusters among post-treatment BCS and determine symptom cluster improvement following the Mindfulness-Based Stress Reduction for Breast Cancer (MBSR(BC)) program. METHODS: Three hundred twenty-two Stage 0-III post-treatment BCS were randomly assigned to either a six-week MBSR(BC) program or usual care. Psychological (depression, anxiety, stress, and fear of recurrence), physical (fatigue, pain, sleep, and drowsiness), and cognitive symptoms and quality of life were assessed at baseline, six, and 12 weeks, along with demographic and clinical history data at baseline. A three-step analytic process included the error-accounting models of factor analysis and structural equation modeling. RESULTS: Four symptom clusters emerged at baseline: pain, psychological, fatigue, and cognitive. From baseline to six weeks, the model demonstrated evidence of MBSR(BC) effectiveness in both the psychological (anxiety, depression, perceived stress and QOL, emotional well-being) (P = 0.007) and fatigue (fatigue, sleep, and drowsiness) (P < 0.001) clusters. Results between six and 12 weeks showed sustained effects, but further improvement was not observed. CONCLUSION: Our results provide clinical effectiveness evidence that MBSR(BC) works to improve symptom clusters, particularly for psychological and fatigue symptom clusters, with the greatest improvement occurring during the six-week program with sustained effects for several weeks after MBSR(BC) training. TRIAL REGISTRATION: Name and URL of Registry: ClinicalTrials.gov. Registration number: NCT01177124.

LRRK2 overexpression alters glutamatergic presynaptic plasticity, striatal dopamine tone, postsynaptic signal transduction, motor activity and memory.

Mutations in leucine-rich repeat kinase 2 (Lrrk2) are the most common genetic cause of Parkinson's disease (PD), a neurodegenerative disorder affecting 1-2% of those >65 years old. The neurophysiology of LRRK2 remains largely elusive, although protein loss suggests a role in glutamatergic synapse transmission and overexpression studies show altered dopamine release in aged mice. We show that glutamate transmission is unaltered onto striatal projection neurons (SPNs) of adult LRRK2 knockout mice and that adult animals exhibit no detectable cognitive or motor deficits. Basal synaptic transmission is also unaltered in SPNs of LRRK2 overexpressing mice, but they do exhibit clear alterations to D2-receptor-mediated short-term synaptic plasticity, behavioral hypoactivity and impaired recognition memory. These phenomena are associated with decreased striatal dopamine tone and abnormal dopamine- and cAMP-regulated phosphoprotein 32 kDa signal integration. The data suggest that LRRK2 acts at the nexus of dopamine and glutamate signaling in the adult striatum, where it regulates dopamine levels, presynaptic glutamate release via D2-dependent synaptic plasticity and dopamine-receptor signal transduction.

Synaptic function is modulated by LRRK2 and glutamate release is increased in cortical neurons of G2019S LRRK2 knock-in mice.

Mutations in Leucine-Rich Repeat Kinase-2 (LRRK2) result in familial Parkinson's disease and the G2019S mutation alone accounts for up to 30% in some ethnicities. Despite this, the function of LRRK2 is largely undetermined although evidence suggests roles in phosphorylation, protein interactions, autophagy and endocytosis. Emerging reports link loss of LRRK2 to altered synaptic transmission, but the effects of the G2019S mutation upon synaptic release in mammalian neurons are unknown. To assess wild type and mutant LRRK2 in established neuronal networks, we conducted immunocytochemical, electrophysiological and biochemical characterization of >3 week old cortical cultures of LRRK2 knock-out, wild-type overexpressing and G2019S knock-in mice. Synaptic release and synapse numbers were grossly normal in LRRK2 knock-out cells, but discretely reduced glutamatergic activity and reduced synaptic protein levels were observed. Conversely, synapse density was modestly but significantly increased in wild-type LRRK2 overexpressing cultures although event frequency was not. In knock-in cultures, glutamate release was markedly elevated, in the absence of any change to synapse density, indicating that physiological levels of G2019S LRRK2 elevate probability of release. Several pre-synaptic regulatory proteins shown by others to interact with LRRK2 were expressed at normal levels in knock-in cultures; however, synapsin 1 phosphorylation was significantly reduced. Thus, perturbations to the pre-synaptic release machinery and elevated synaptic transmission are early neuronal effects of LRRK2 G2019S. Furthermore, the comparison of knock-in and overexpressing cultures suggests that one copy of the G2019S mutation has a more pronounced effect than an ~3-fold increase in LRRK2 protein. Mutant-induced increases in transmission may convey additional stressors to neuronal physiology that may eventually contribute to the pathogenesis of Parkinson's disease.

DNAJC13 mutations in Parkinson disease.

A Saskatchewan multi-incident family was clinically characterized with Parkinson disease (PD) and Lewy body pathology. PD segregates as an autosomal-dominant trait, which could not be ascribed to any known mutation. DNA from three affected members was subjected to exome sequencing. Genome alignment, variant annotation and comparative analyses were used to identify shared coding mutations. Sanger sequencing was performed within the extended family and ethnically matched controls. Subsequent genotyping was performed in a multi-ethnic case-control series consisting of 2928 patients and 2676 control subjects from Canada, Norway, Taiwan, Tunisia, and the USA. A novel mutation in receptor-mediated endocytosis 8/RME-8 (DNAJC13 p.Asn855Ser) was found to segregate with disease. Screening of cases and controls identified four additional patients with the mutation, of which two had familial parkinsonism. All carriers shared an ancestral DNAJC13 p.Asn855Ser haplotype and claimed Dutch-German-Russian Mennonite heritage. DNAJC13 regulates the dynamics of clathrin coats on early endosomes. Cellular analysis shows that the mutation confers a toxic gain-of-function and impairs endosomal transport. DNAJC13 immunoreactivity was also noted within Lewy body inclusions. In late-onset disease which is most reminiscent of idiopathic PD subtle deficits in endosomal receptor-sorting/recycling are highlighted by the discovery of pathogenic mutations VPS35, LRRK2 and now DNAJC13. With this latest discovery, and from a neuronal perspective, a temporal and functional ecology is emerging that connects synaptic exo- and endocytosis, vesicular trafficking, endosomal recycling and the endo-lysosomal degradative pathway. Molecular deficits in these processes are genetically linked to the phenotypic spectrum of parkinsonism associated with Lewy body pathology.