4,155 research outputs found
α2 Integrin-Dependent Suppression of Pancreatic Adenocarcinoma Cell Invasion Involves Ectodomain Regulation of Kallikrein-Related Peptidase-5
Previous reports demonstrate that the α2-integrin (α2) mediates pancreatic ductal adenocarcinoma (PDAC) cell interactions with collagens. We found that while well-differentiated cells use α2 exclusively to adhere and migrate on collagenI, poorly differentiated PDAC cells demonstrate reduced reliance on, or complete loss of, α2. Since well-differentiated PDAC lines exhibit reduced in vitro invasion and α2-blockade suppressed invasion of well-differentiated lines exclusively, we hypothesized that α2 may suppress the malignant phenotype in PDAC. Accordingly, ectopic expression of α2 retarded in vitro invasion and maintenance on collagenI exacerbated this effect. Affymetrix profiling revealed that kallikrein-related peptidase-5 (KLK5) was specifically upregulated by α2, and reduced α2 and KLK5 expression was observed in poorly differentiated PDAC cells in situ. Accordingly, well-differentiated PDAC lines express KLK5, and KLK5 blockade increased the invasion of KLK5-positive lines. The α2-cytoplasmic domain was dispensable for these effects, demonstrating that the α2-ectodomain and KLK5 coordinately regulate a less invasive phenotype in PDAC
CFO Promotion-based Incentives and Earnings Management
This study examines whether CFO promotion-based incentives induce opportunistic reporting activities. We find that CFO promotion-based incentives, measured by the pay gap between the CEO and the CFO, are positively associated with accruals management and accounting misconduct in the pre-SOX period and the probability of meeting or beating analysts’ forecasts in both the pre- and post-SOX periods. Further analysis shows that CFO promotion-based incentives are negatively associated with real earnings management in both the pre- and post-SOX periods. In addition, we find some evidence that the association between CFO promotion-based incentives and opportunistic reporting activities is stronger before CEO turnovers. We also document that CFOs engage in more opportunistic financial reporting when the pay gap between the CFO and other VPs is greater. Overall, our findings suggest that CFO promotion-based incentives may encourage CFOs to engage in opportunistic reporting activities but mitigate real earnings management
Morphine-induced Suppression of Conditioned Stimulus Intake: Effects of Stimulus Type and Insular Cortex Lesions
Intake of an unconditionally preferred taste stimulus (e.g., saccharin) is reduced by contingent administration of a drug of abuse (e.g., morphine). We examined the influence of insular cortex (IC) lesions on morphine-induced suppression of an olfactory cue and two taste stimuli with different levels of perceived innate reward value. Two major findings emerged from this study. First, morphine suppressed intake of an aqueous odor as well as each taste stimulus in neurologically intact rats. Second, IC lesions disrupted morphine-induced suppression of the taste stimuli but not the aqueous odor cue. These results indicate that the perceived innate reward value of the CS is not a factor that governs drug-induced intake suppression
Insular Cortex and Consummatory Successive Negative Contrast in the Rat
Rats that are expecting a high value reward (e.g., 1.0 M sucrose) show an exaggerated underresponding when they are instead given a low value reward (e.g., 0.15% saccharin), an effect termed successive negative contrast (SNC). In the present experiment, insular cortex-lesioned (ICX) rats showed normal responsivity to sucrose and saccharin prior to the reward downshift. However, when switched from sucrose to saccharin during the postshift trials these rats displayed no evidence of SNC. Indeed, over the downshift trials these ICX rats consistently drank more saccharin than the ICX rats maintained on saccharin throughout the experiment. Potential interpretations are discussed including a lesion-induced impairment in the ability to accurately recognize the novelty of the postshift saccharin stimulus
Conditioned Taste Aversion and Latent Inhibition Following Extensive Taste Preexposure in Rats with Insular Cortex Lesions
Lesions of the insular cortex (IC) attenuate acquisition of conditioned taste aversions (CTAs). We have suggested that this impairment is the expected consequence of a failure of IC-lesioned (ICX) rats to recognize unfamiliar taste stimuli as novel. That is, ICX rats treat novel taste stimuli as if they are familiar and as a result show a latent inhibition-like retardation of learning. This account anticipates that ICX rats should acquire CTAs at the same slow rate as normal rats that are familiar with the taste stimulus. The present experiment confirmed this hypothesis in a design that compared CTA acquisition in normal and ICX rats following either extensive taste familiarization or no taste familiarization prior to conditioning
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