Brain mitochondrial dysfunction is hallmark pathology of Alzheimer’s disease (AD). Recently, the role of synaptosomal mitochondrial dysfunction in the development of synaptic injury in AD has received increasing attention. Synaptosomal mitochondria are a subgroup of neuronal mitochondria specifically locating at synapses. They play an essential role in fueling synaptic functions by providing energy on the site; and their defects may lead to synaptic failure, which is an early and pronounced pathology in AD. In our previous studies we have determined early synaptosomal mitochondrial dysfunction in an AD animal model (J20 line) overexpressing human Amyloid beta (Aβ), the key mediator of AD. In view of the limitations of J20 line mice in representing the full aspects of amyloidopathy in AD cases, we employed 5xFAD mice which are thought to be a desirable paradigm of amyloidopathy as seen in AD subjects. In addition, we have also examined the status of synaptosomal mitochondrial dynamics as well as Parkin-mediated mitophagy which have not been previously investigated in this mouse model. In comparison to nontransgenic (nonTg mice), 5xFAD mice demonstrated prominent synaptosomal mitochondrial dysfunction. Moreover, synaptosomal mitochondria from the AD mouse model displayed imbalanced mitochondrial dynamics towards fission along with activated Parkin and LC3BII recruitment correlating to spatial learning & memory impairments in 5xFAD mice in an age-dependent manner. These results suggest that synaptosomal mitochondrial deficits are primary pathology in Aβ-rich environments and further confirm the relevance of synaptosomal mitochondrial deficits to the development of AD.

Inhibition of the bromodomain and extra-terminal (BET) proteins is a promising therapeutic strategy for various hematologic cancers. Previous studies suggest that BET inhibitors constrain tumor cell proliferation and survival mainly through the suppression of MYC transcription and activity. However, suppression of the transcription of additional genes also contributes to the antitumor activity of BET inhibitors but is less well understood. Here we examined the therapeutic potential of CPI-0610, a potent BET inhibitor currently undergoing phase I clinical testing, in multiple myeloma (MM). CPI-0610 displays potent cytotoxicity against MM cell lines and patient-derived MM cells through G cell cycle arrest and caspase-dependent apoptosis. CPI-0610-mediated BET inhibition overcomes the protective effects conferred by cytokines and bone marrow stromal cells. We also confirmed the in vivo efficacy of CPI-0610 in a MM xenograft mouse model. Our study found IKZF1 and IRF4 to be among the primary targets of CPI-0610, along with MYC. Given that immunomodulatory drugs (IMiDs) stabilize cereblon and facilitate Ikaros degradation in MM cells, we combined it with CPI-0610. Combination studies of CPI-0610 with IMiDs show in vitro synergism, in part due to concomitant suppression of IKZF1, IRF4 and MYC, providing a rationale for clinical testing of this drug combination in MM patients.

Estrogen receptor α (ERα)low/− tumors are associated with breast cancer (BCa) endocrine resistance, where ERα low tumors show a poor prognosis and a molecular profile similar to triple negative BCa tumors. Interleukin‐1 (IL‐1) downregulates ERα accumulation in BCa cell lines, yet the cells can remain viable. In kind, IL‐1 and ERα show inverse accumulation in BCa patient tumors and IL‐1 is implicated in BCa progression. IL‐1 represses the androgen receptor hormone receptor in prostate cancer cells concomitant with the upregulation of the prosurvival, autophagy‐related protein, Sequestome‐1 (p62/SQSTM1; hereinafter, p62); and given their similar etiology, we hypothesized that IL‐1 also upregulates p62 in BCa cells concomitant with hormone receptor repression. To test our hypothesis, BCa cell lines were exposed to conditioned medium from IL‐1‐secreting bone marrow stromal cells (BMSCs), IL‐1, or IL‐1 receptor antagonist. Cells were analyzed for the accumulation of ERα, progesterone receptor (PR), p62, or the autophagosome membrane protein, microtubule‐associated protein 1 light chain 3 (LC3), and for p62‐LC3 interaction. We found that IL‐1 is sufficient to mediate BMSC‐induced ERα and PR repression, p62 and autophagy upregulation, and p62‐LC3 interaction in ERα+/PR+ BCa cell lines. However, IL‐1 does not significantly elevate the high basal p62 accumulation or high basal autophagy in the ERα−/PR− BCa cell lines. Thus, our observations imply that IL‐1 confers a prosurvival ERα−/PR− molecular phenotype in ERα+/PR+ BCa cells that may be dependent on p62 function and autophagy and may underlie endocrine resistance.

Pan proviral integrations of Moloney virus (PIM) inhibition in multiple myeloma (MM) results in reduced cell viability in tested human-derived MM cell lines and reduces tumor burden in xenograft mouse models, making PIMs important therapeutic targets for the disease. PIM kinase inhibitors are currently being tested clinically in MM. We sought to elucidate the role of the various PIMs in MM. Our data demonstrate that Pim2 has a significant role in MM cell cytotoxicity. Our data provide evidence for a novel role for Pim2 in the regulation of the DNA damage response (DDR). Knockdown of Pim2 upregulates several downstream DDR markers, mimicking the effects of doxorubicin (Dox) treatment of MM cells, and suggesting a role for the kinase as a negative regulator of this pathway. Dox-induced DNA damage results in a decrease in Pim2 levels, placing the kinase directly downstream of the site of Dox-DNA binding. Overexpression of Pim2 confers a slight survival advantage against Dox through antiapoptotic activity, further underscoring its relevance in the DDR pathway. These data provide insights into a novel mechanism of PIM kinase activity and provide the framework for designing therapeutic approaches in MM.

No abstract

Purpose Flourine-18-flortaucipir tau positron emission tomography (PET) was developed for the detection for Alzheimer’s disease. Human imaging studies have begun to investigate its use in chronic traumatic encephalopathy (CTE). Flortaucipir-PET to autopsy correlation studies in CTE are needed for diagnostic validation. We examined the association between end-of-life flortaucipir PET and postmortem neuropathological measurements of CTE-related tau in six former American football players. Methods Three former National Football League players and three former college football players who were part of the DIAGNOSE CTE Research Project died and agreed to have their brains donated. The six players had flortaucipir (tau) and florbetapir (amyloid) PET prior to death. All brains from the deceased participants were neuropathologically evaluated for the presence of CTE. On average, the participants were 59.0 (SD = 9.32) years of age at time of PET. PET scans were acquired 20.33 (SD = 13.08) months before their death. Using Spearman correlation analyses, we compared flortaucipir standard uptake value ratios (SUVRs) to digital slide-based AT8 phosphorylated tau (p-tau) density in a priori selected composite cortical, composite limbic, and thalamic regions-of-interest (ROIs). Results Four brain donors had autopsy-confirmed CTE, all with high stage disease (n = 3 stage III, n = 1 stage IV). Three of these four met criteria for the clinical syndrome of CTE, known as traumatic encephalopathy syndrome (TES). Two did not have CTE at autopsy and one of these met criteria for TES. Concomitant pathology was only present in one of the non-CTE cases (Lewy body) and one of the CTE cases (motor neuron disease). There was a strong association between flortaucipir SUVRs and p-tau density in the composite cortical (ρ = 0.71) and limbic (ρ = 0.77) ROIs. Although there was a strong association in the thalamic ROI (ρ = 0.83), this is a region with known off-target binding. SUVRs were modest and CTE and non-CTE cases had overlapping SUVRs and discordant p-tau density for some regions. Conclusions Flortaucipir-PET could be useful for detecting high stage CTE neuropathology, but specificity to CTE p-tau is uncertain. Off-target flortaucipir binding in the hippocampus and thalamus complicates interpretation of these associations. In vivo biomarkers that can detect the specific p-tau of CTE across the disease continuum are needed.

The bromodomain and extraterminal (BET) proteins recognize acetylated lysine residues on histone tails and recruit transcriptional machinery to promote gene expression. The BET proteins are attractive drug targets because they regulate the expression of MYC, BCL2 and NF- κB target genes. We investigated the therapeutic potential of CPI-0610, an inhibitor of BET proteins, currently in Phase I testing in multiple myeloma (MM). Our preliminary data show that human MM cell lines are sensitive to BET inhibition, with IC50 values of 800-1000 nM being observed in MM.1S, MM.1R, RPMI-8226, LR5, H929 and U266 cell lines in 72h culture. We further show that CPI-0610 inhibits MM cell growth in the presence of cytokines and when co-cultured with bone marrow stromal cells. CPI-0610 induces apoptosis and G1 cell cycle arrest associated with MYC downregulation. However, protein levels of BCL2, NF- κ B and MCL1 remain unchanged in MM cells upon BET inhibition. The zinc finger transcriptional factor Ikaros (IKZF1) is highly expressed in MM (GEO dataset GSE36133). It is actively transcribed in the MM.1S cell line with an active transcription start site occupied by BRD4 and MED1 (Loven J et al. Cell 2013). Interestingly, we found that CPI-0610 suppresses Ikaros and IRF4 expression at the levels of both transcription and protein in MM cells. With the use of doxycycline-inducible shRNAs targeting IKZF1, IRF4 and MYC, we identified a positive feedback mechanism that is critical for MM cell survival. Individual knockdown of IRF4, IKZF1 or MYC all lead to induction of apoptosis in MM cells. Suppression of IRF4 decreases both Ikaros and MYC protein expression, suggesting that IRF4 is upstream of both Ikaros and MYC. Downregulation of MYC protein expression is observed following IKZF1 knockdown, suggesting that MYC is downstream of Ikaros. Finally, we observed a decrease in IRF4 protein level upon MYC downregulation, implicating a feedback mechanism from MYC to IRF4. Together, these data illustrate a molecular sequence of events going from IRF4 to IKZF1 to MYC and then back to IRF4, forming a positive feedback loop in MM cells. Based on the observation that shRNA-mediated knockdown of MYC and IKZF1 are toxic to MM, we combined CPI-0610 with lenalidomide, an immunomodulatory drug which stabilizes cereblon and facilitates Ikaros degradation in MM cells (Kronke J et al., and Lu G et al., Science 2014). We observed a synergistic cytotoxic effect in the cell lines tested (MM.1S and RPMI-8226). The enhanced cytotoxic effect of the combined treatment in MM cell lines is due in part to suppression of MYC, IKZF1 and IRF4. Ongoing studies will focus on understanding the molecular mechanism underlying this synergistic combination and validating its efficacy in vivo in order to provide a rationale for clinical protocols of BET inhibitors in MM. Disclosures Mertz: Constellation Pharmaceuticals: Employment, Equity Ownership. Sims:Constellation Pharmaceuticals: Employment, Equity Ownership. Cooper:Constellation Pharmaceuticals: Employment, Equity Ownership. Raje:Celgene Corporation: Consultancy; Eli Lilly: Research Funding; Takeda: Consultancy; Amgen: Consultancy; Onyx: Consultancy; AstraZeneca: Research Funding; Novartis: Consultancy; BMS: Consultancy; Acetylon: Research Funding; Millenium: Consultancy.

This paper presents a survey of relevant transactional and recovery issues for the development of processes that are composed of web services in a service-oriented architecture (SOA). A process in an SOA is not a traditional ACID transaction due to the loosely-coupled, autonomous, and heterogeneous nature of the execution environment. As a result, processes that are composed of web services can pose challenges for data consistency in the context of concurrent processes that are accessing shared data. This paper first outlines past research on advanced transaction models and transactional workflows that has established the framework for coordination and recovery techniques associated with web service composition. The standards that have evolved to support web service composition and a coordinated commit process among web services are then presented. The paper then elaborates on research projects that address data consistency issues for web service composition, outlining relaxed locking techniques, data dependency analysis techniques, and other modularization techniques for addressing user-defined correctness, flexible recovery actions, and cross-cutting concerns. Failure recovery strategies for Web Services are also addressed, describing how current research builds on the foundation provided by advanced transaction models to perform recovery for processes composed of Web Services. The overview of failure recovery strategies also includes self-healing mechanisms and