Estrogen receptor beta in astrocytes modulates cognitive function in mid-age female mice.

Menopause is associated with cognitive deficits and brain atrophy, but the brain region and cell-specific mechanisms are not fully understood. Here, we identify a sex hormone by age interaction whereby loss of ovarian hormones in female mice at midlife, but not young age, induced hippocampal-dependent cognitive impairment, dorsal hippocampal atrophy, and astrocyte and microglia activation with synaptic loss. Selective deletion of estrogen receptor beta (ERß) in astrocytes, but not neurons, in gonadally intact female mice induced the same brain effects. RNA sequencing and pathway analyses of gene expression in hippocampal astrocytes from midlife female astrocyte-ERß conditional knock out (cKO) mice revealed Gluconeogenesis I and Glycolysis I as the most differentially expressed pathways. Enolase 1 gene expression was increased in hippocampi from both astrocyte-ERß cKO female mice at midlife and from postmenopausal women. Gain of function studies showed that ERß ligand treatment of midlife female mice reversed dorsal hippocampal neuropathology.

A randomized, double-blind, placebo-controlled phase 1b/2 study of ralimetinib, a p38 MAPK inhibitor, plus gemcitabine and carboplatin versus gemcitabine and carboplatin for women with recurrent platinum-sensitive ovarian cancer.

OBJECTIVE: This phase 1b/2 clinical trial (NCT01663857) evaluated the efficacy of ralimetinib in combination with gemcitabine (G) and carboplatin (C), followed by maintenance ralimetinib, for patients with recurrent platinum-sensitive epithelial ovarian cancer. METHODS: Phase 1b was to determine the recommended phase 2 dose (RP2D) of ralimetinib administered Q12H on Days 1-10 (q21d) in combination with G (1000 mg/m2, Days 3 and 10) and C (AUC 4, Day 3) for six cycles. In phase 2, patients were randomized double-blind 1:1 to ralimetinib (R)+GC or placebo (P)+GC, for six cycles, followed by ralimetinib 300 mg Q12H or placebo on Days 1-14, q28d. RESULTS: 118 patients received at least one dose of ralimetinib or placebo; eight in phase 1b and 110 in phase 2 (R+GC, N = 58; P+GC, N = 52). The RP2D for R+GC was 200 mg Q12H. The study met its primary objective of a statistically significant difference in PFS (median: R+GC, 10.3 mo vs. P+GC, 7.9 mo; hazard ratio [HR] = 0.773, P = 0.2464, against a two-sided false positive rate of 0.4). Secondary objectives were not statistically significant for median overall survival (R+GC, 29.2 mo vs. P+GC, 25.1 mo; HR = 0.827, P = 0.4686) or overall response rate (R+GC 46.6% vs. P+GC, 46.2%; P = 0.9667). The safety profile of R+GC therapy was mainly consistent with safety of the chemotherapy backbone alone. Grade 3/4 elevated alanine aminotransferase was more common in the ralimetinib arm. CONCLUSIONS: Addition of ralimetinib to GC resulted in a modest improvement in PFS.

Parent-of-origin differences in DNA methylation of X chromosome genes in T lymphocytes.

Many autoimmune diseases are more frequent in females than in males in humans and their mouse models, and sex differences in immune responses have been shown. Despite extensive studies of sex hormones, mechanisms underlying these sex differences remain unclear. Here, we focused on sex chromosomes using the "four core genotypes" model in C57BL/6 mice and discovered that the transcriptomes of both autoantigen and anti-CD3/CD28 stimulated CD4+ T lymphocytes showed higher expression of a cluster of 5 X genes when derived from XY as compared to XX mice. We next determined if higher expression of an X gene in XY compared to XX could be due to parent-of-origin differences in DNA methylation of the X chromosome. We found a global increase in DNA methylation on the X chromosome of paternal as compared to maternal origin. Since DNA methylation usually suppresses gene expression, this result was consistent with higher expression of X genes in XY cells because XY cells always express from the maternal X chromosome. In addition, gene expression analysis of F1 hybrid mice from CAST × FVB reciprocal crosses showed preferential gene expression from the maternal X compared to paternal X chromosome, revealing that these parent-of-origin effects are not strain-specific. SJL mice also showed a parent-of-origin effect on DNA methylation and X gene expression; however, which X genes were affected differed from those in C57BL/6. Together, this demonstrates how parent-of-origin differences in DNA methylation of the X chromosome can lead to sex differences in gene expression during immune responses.

The X-linked histone demethylase Kdm6a in CD4+ T lymphocytes modulates autoimmunity.

Multiple sclerosis (MS) is a putative T cell-mediated autoimmune disease. As with many autoimmune diseases, females are more susceptible than males. Sexual dimorphisms may be due to differences in sex hormones, sex chromosomes, or both. Regarding sex chromosome genes, a small percentage of X chromosome genes escape X inactivation and have higher expression in females (XX) compared with males (XY). Here, high-throughput gene expression analysis in CD4+ T cells showed that the top sexually dimorphic gene was Kdm6a, a histone demethylase on the X chromosome. There was higher expression of Kdm6a in females compared with males in humans and mice, and the four core genotypes (FCG) mouse model showed higher expression in XX compared with XY. Deletion of Kdm6a in CD4+ T cells ameliorated clinical disease and reduced neuropathology in the classic CD4+ T cell-mediated autoimmune disease experimental autoimmune encephalomyelitis (EAE). Global transcriptome analysis in CD4+ T cells from EAE mice with a specific deletion of Kdm6a showed upregulation of Th2 and Th1 activation pathways and downregulation of neuroinflammation signaling pathways. Together, these data demonstrate that the X escapee Kdm6a regulates multiple immune response genes, providing a mechanism for sex differences in autoimmune disease susceptibility.

Conformational Dynamics and Cooperativity Drive the Specificity of a Protein-Ligand Interaction.

Molecular recognition is critical for the fidelity of signal transduction in biology. Conversely, the disruption of protein-protein interactions can lead to disease. Thus, comprehension of the molecular determinants of specificity is essential for understanding normal biological signaling processes and for the development of precise therapeutics. Although high-resolution structures have provided atomic details of molecular interactions, much less is known about the influence of cooperativity and conformational dynamics. Here, we used the Tiam2 PSD-95/Dlg/ZO-1 (PDZ) domain and a quadruple mutant (QM), engineered by swapping the identity of four residues important for specificity in the Tiam1 PDZ into the Tiam2 PDZ domain, as a model system to investigate the role of cooperativity and dynamics in PDZ ligand specificity. Surprisingly, equilibrium binding experiments found that the ligand specificity of the Tiam2 QM was switched to that of the Tiam1 PDZ. NMR-based studies indicated that Tiam2 QM PDZ, but not other mutants, had extensive microsecond to millisecond motions distributed throughout the entire domain suggesting structural cooperativity between the mutated residues. Thermodynamic analyses revealed energetic cooperativity between residues in distinct specificity subpockets that was dependent upon the identity of the ligand, indicating a context-dependent binding mechanism. Finally, isothermal titration calorimetry experiments showed distinct entropic signatures along the mutational trajectory from the Tiam2 wild-type to the QM PDZ domain. Collectively, our studies provide unique insights into how structure, conformational dynamics, and thermodynamics combine to modulate ligand-binding specificity and have implications for the evolution, regulation, and design of protein-ligand interactions.

Evaluation of Prexasertib, a Checkpoint Kinase 1 Inhibitor, in a Phase Ib Study of Patients with Squamous Cell Carcinoma.

Purpose: Prexasertib, a checkpoint kinase 1 inhibitor, demonstrated single-agent activity in patients with advanced squamous cell carcinoma (SCC) in the dose-escalation portion of a phase I study (NCT01115790). Monotherapy prexasertib was further evaluated in patients with advanced SCC.Patients and Methods: Patients were given prexasertib 105 mg/m2 as a 1-hour infusion on day 1 of a 14-day cycle. Expansion cohorts were defined by tumor and treatment line. Safety, tolerability, efficacy, and exploratory biomarkers were analyzed.Results: Prexasertib was given to 101 patients, including 26 with SCC of the anus, 57 with SCC of the head and neck (SCCHN), and 16 with squamous cell non-small cell lung cancer (sqNSCLC). Patients were heavily pretreated (49% ≥3 prior regimens). The most common treatment-related adverse event was grade 4 neutropenia (71%); 12% of patients had febrile neutropenia. Median progression-free survival was 2.8 months [90% confidence interval (CI), 1.9-4.2] for SCC of the anus, 1.6 months (90% CI, 1.4-2.8) for SCCHN, and 3.0 months (90% CI, 1.4-3.9) for sqNSCLC. The clinical benefit rate at 3 months (complete response + partial response + stable disease) across tumors was 29% (23% SCC of the anus, 28% SCCHN, 44% sqNSCLC). Four patients with SCC of the anus had partial or complete response [overall response rate (ORR) = 15%], and three patients with SCCHN had partial response (ORR = 5%). Biomarker analyses focused on genes that altered DNA damage response or increased replication stress.Conclusions: Prexasertib demonstrated an acceptable safety profile and single-agent activity in patients with advanced SCC. The prexasertib maximum-tolerated dose of 105 mg/m2 was confirmed as the recommended phase II dose. Clin Cancer Res; 24(14); 3263-72. ©2018 AACR.

The importance of studying sex differences in disease: The example of multiple sclerosis.

To date, scientific research has often focused on one sex, with assumptions that study of the other sex would yield similar results. However, many diseases affect males and females differently. The sex of a patient can affect the risk for both disease susceptibility and progression. Such differences can be brought to the laboratory bench to be investigated, potentially bringing new treatments back to the clinic. This method of research, known as a "bedside to bench to bedside" approach, has been applied to studying sex differences in multiple sclerosis (MS). Females have greater susceptibly to MS, while males have worse disease progression. These two characteristics of the disease are influenced by the immune system and the nervous system, respectively. Thus, sex differences in each system must be studied. Personalized medicine has been at the forefront of research recently, and studying sex differences in disease fits with this initiative. This review will discuss the known sex differences in MS and highlight how investigating them can lead to new insights and potential treatments for both men and women. © 2016 Wiley Periodicals, Inc.

Phase I Study of LY2606368, a Checkpoint Kinase 1 Inhibitor, in Patients With Advanced Cancer.

PURPOSE: The primary objective was to determine safety, toxicity, and a recommended phase II dose regimen of LY2606368, an inhibitor of checkpoint kinase 1, as monotherapy. PATIENTS AND METHODS: This phase I, nonrandomized, open-label, dose-escalation trial used a 3 + 3 dose-escalation scheme and included patients with advanced solid tumors. Intravenous LY2606368 was dose escalated from 10 to 50 mg/m(2) on schedule 1 (days 1 to 3 every 14 days) or from 40 to 130 mg/m(2) on schedule 2 (day 1 every 14 days). Safety measures and pharmacokinetics were assessed, and pharmacodynamics were measured in blood, hair follicles, and circulating tumor cells. RESULTS: Forty-five patients were treated; seven experienced dose-limiting toxicities (all hematologic). The maximum-tolerated doses (MTDs) were 40 mg/m(2) (schedule 1) and 105 mg/m(2) (schedule 2). The most common related grade 3 or 4 treatment-emergent adverse events were neutropenia, leukopenia, anemia, thrombocytopenia, and fatigue. Grade 4 neutropenia occurred in 73.3% of patients and was transient (typically < 5 days). Febrile neutropenia incidence was low (7%). The LY2606368 exposure over the first 72 hours (area under the curve from 0 to 72 hours) at the MTD for each schedule coincided with the exposure in mouse xenografts that resulted in maximal tumor responses. Minor intra- and intercycle accumulation of LY2606368 was observed at the MTDs for both schedules. Two patients (4.4%) had a partial response; one had squamous cell carcinoma (SCC) of the anus and one had SCC of the head and neck. Fifteen patients (33.3%) had a best overall response of stable disease (range, 1.2 to 6.7 months), six of whom had SCC. CONCLUSION: An LY2606368 dose of 105 mg/m(2) once every 14 days is being evaluated as the recommended phase II dose in dose-expansion cohorts for patients with SCC.

Increasing Colorectal Cancer Screening at Community-Based Primary Care Clinics in San Francisco.

CONTEXT: Adult colorectal cancer screening (CRCS) can lower disease incidence and mortality. However, widespread implementation is inconsistent, especially in the public sector. While specific interventions to increase CRCS have been identified, firsthand accounts of CRCS improvement efforts using multiple techniques in public sector settings are lacking. OBJECTIVE: A program evaluation was conducted to assess the effect of implementing a culture of continuous quality improvement (QI) on CRCS practices and prevalence. A multipronged incremental effort over more than a decade to increase CRCS at the San Francisco Department of Public Health is described. SETTING: Community-based primary care clinics. PARTICIPANTS: Departmental activities and 5 clinics providing full-scope primary care to CRCS-eligible adults who participated in departmental activities and outreach interventions were assessed. MAIN OUTCOME MEASURES: Departmental and clinic-specific CRCS activities and prevalence. RESULTS: Efforts included departmental prioritization; data-driven QI incorporating routine data sharing (monthly reports and data walls); departmental and clinic-specific QI committees; panel management (a team approach to generation of eligibility lists prior to scheduled visits, routinely offering screening during appointments or mailing test kits for patients without appointments); and departmental mail and phone outreach events. Screening ranged from 36.6% to 54.4% in 2010; in 2013, it ranged from 43.6% to 70.2%. Increases occurred consistently over that time in 3 of the 5 clinics and ranged from 1.1% to 14.5%; decreases occurred during 2 intervals in 2 clinics and ranged from 2.3% to 4.3%. CONCLUSION: CRCS prevalence can be markedly improved in the public sector with a data-driven panel management approach supported by departmental and clinic-specific QI committees and group outreach events. Continued prioritization of and focus on CRCS is required to ensure long-term success. Even small increases will result in avoidable morbidity and mortality associated with this highly preventable disease.