Rationale: Glucocorticoids (GCs) are highly effective in the treatment of asthma. However, some individuals have GC-insensitive asthma. Objectives: To evaluate the functional response to steroids of bronchoalveolar lavage (BAL) cells from sites of airway inflammation from patients with GC-insensitive versus GC-sensitive asthma. As well, to attempt to define the functional role of glucocorticoid receptor (GCR)␤ (a splicing variant, and dominant negative inhibitor of, the classic GCR␣) in controlling GCR␣ nuclear translocation and transactivation at a molecular level. Methods and Measurements: Fiberoptic bronchoscopy with collection of BAL fluid was performed on seven patients with GC-sensitive asthma and eight patients with GC-insensitive asthma. GCR␣ cellular shuttling in response to 10 ؊6 M dexamethasone treatment and GCR␤ expression were analyzed in BAL cells by immunofluorescence staining. The effects of overexpression and silencing of GCR␤ mRNA on GCR␣ function were assessed. Main Results: Significantly reduced nuclear translocation of GCR␣ in response to steroids was found in BAL cells from patients with GC-insensitive asthma. BAL macrophages from patients with GCinsensitive asthma had significantly increased levels of cytoplasmic and nuclear GCR␤. It was demonstrated that GCR␣ nuclear translocation and its transactivation properties were proportionately reduced by level of viral transduction of the GCR␤ gene into the DO-11.10 cell line. RNA silencing of GCR␤ mRNA in human BAL macrophages from patients with GC-insensitive asthma resulted in enhanced dexamethasone-induced GCR␣ transactivation. Conclusions: GC insensitivity is associated with loss of GCR␣ nuclear translocation in BAL cells and elevated GCR␤, which may inhibit GCR␣ transactivation in response to steroids.

Vacuole- and mitochondria-specific cargo adaptors compete for an overlapping binding site on Myo2 to determine the inheritance of these organelles during budding.

Organelle inheritance occurs during cell division. In Saccharomyces cerevisiae, inheritance of the vacuole, and the distribution of mitochondria and cortical endoplasmic reticulum are regulated by Ptc1p, a type 2C protein phosphatase. Here we show that PTC1/VAC10 controls the distribution of additional cargoes moved by a myosin-V motor. These include peroxisomes, secretory vesicles, cargoes of Myo2p, and ASH1 mRNA, a cargo of Myo4p. We find that Ptc1p is required for the proper distribution of both Myo2p and Myo4p. Surprisingly, PTC1 is also required to maintain the steady-state levels of organelle-specific receptors, including Vac17p, Inp2p, and Mmr1p, which attach Myo2p to the vacuole, peroxisomes, and mitochondria, respectively. Furthermore, Vac17p fused to the cargo-binding domain of Myo2p suppressed the vacuole inheritance defect in ptc1⌬ cells. These findings suggest that PTC1 promotes the association of myosin-V with its organelle-specific adaptor proteins. Moreover, these observations suggest that despite the existence of organelle-specific receptors, there is a higher order regulation that coordinates the movement of diverse cellular components. INTRODUCTIONDuring each cell cycle, cytoplasmic organelles are actively distributed between dividing cells to maintain organelle copy number and volume. The yeast Saccharomyces cerevisiae is an excellent model system for studying the spatial and temporal control of organelle inheritance. In yeast, several organelles are transmitted from mother to daughter cells. These include the vacuole, mitochondria, the endoplasmic reticulum (ER), late-Golgi elements and peroxisomes (reviewed in Weisman, 2006).Early in the cell cycle, a portion of each organelle is transported into the emerging bud. The polarized transport of most organelles from the mother to the bud is an active process that requires the actin cytoskeleton, myosin-V motors, and receptor proteins, which physically connect the motor to organelle cargoes (Beach et al., 2000;Yin et al., 2000;Boldogh et al., 2001;Barr, 2002;Bretscher, 2003;Du et al., 2004;Fagarasanu et al., 2006bFagarasanu et al., , 2007Weisman, 2006). Thus, formation of a complex between the motor and receptor protein is important for polarized organelle transport.Similar to yeast, in vertebrates, myosin-V motors move cargoes along the actin cytoskeleton. The best studied cargo of vertebrate myosin-V are melanosomes, which are moved in melanocytes by myosin-Va. Melanosomes attach to myosin-Va through Rab27a and melanophilin (Fukuda and Kuroda, 2002;Wu et al., 2002). Rab27a, through geranylgeranylation, attaches to the melanosome membrane, and melanophilin connects myosin-Va and Rab27a. Myosin-V-based intracellular movement has been analyzed in many other eukaryotes, including frogs, fish, mammals, and plants; plant myosin-XI is the functional homologue of yeast and vertebrate myosin-V ( Kinkema and Schiefelbein, 1994;Provance and Mercer, 1999;Tuma and Gelfand, 1999;Desnos et al., 2007;Li and Nebenfuhr, 2007;Sheets et al., 2007;Shimmen, 2007).Ge...

TPS870 Background: Approximately 96% of CRCs have an MSS phenotype, which results in more immunologically quiescent tumors for which immunotherapies are largely ineffective (Lee et al. 2015; Overman et al. 2016). Pts with MSS CRC and activating RAS mutation (35%–45% of CRCs) have treatment options limited still further because anti-EGFR monoclonal antibodies (eg, cetuximab) are ineffective owing to dominant activation of RAS in the MAPK pathway (Douillard et al. 2014). However, preclinical and preliminary clinical data suggest that MAPK pathway inhibition enhances antigen presentation and T-cell cytotoxicity to positively modulate the efficacy of checkpoint inhibitors (Brea et al. 2016; Bendell et al. 2014). The main objective of this open-label multicenter phase 1b/2 study is to evaluate whether the potential positive modulation of NIVO or NIVO plus IPI, when combined with BINI, translates into clinically meaningful overall response in pts with MSS mCRC and RAS mutation. Methods: The study will enroll ~90 previously treated pts (1 or 2 prior regimens), ~42 in phase 1b and ~48 in phase 2. The primary objective of phase 1b will be to determine the recommended phase 2 dose (RP2D) of BINI in combination with NIVO ± IPI. Dose finding in the doublet arm will begin with BINI 45 mg BID + NIVO 480 mg Q4W; the triplet arm will begin with the BINI RP2D from the doublet arm + NIVO 480 mg Q4W + IPI 1 mg/kg Q8W. In phase 2, pts will be randomized 1:1 to doublet or triplet arms, incorporating the BINI RP2Ds found in phase 1b; treatment will continue in 28-day cycles until disease progression, unacceptable toxicity, withdrawal of consent, initiation of subsequent anticancer therapy, loss to follow-up, or death. The primary objective for phase 2 will be to assess response by RECIST version 1.1. The study will also characterize safety and PK. CT.gov Identifier: Clinical trial information: NCT03271047.