Chronic lymphocytic leukemia (CLL) cells with aggressive clinical properties express lipoprotein lipase (LPL), which generates activating ligands for the nuclear receptor peroxisome proliferator activated receptor (PPAR)α and allows fatty acids to be used as fuel. However, the role of PPARα in CLL is unclear. PPARα was found to be expressed by circulating CLL cells and highly associated with advanced stage disease. Consistent with this observation, palmitate oxidation rates in circulating CLL cells were similar to more conventional fat-burning cells such as muscle. Transgenic expression of PPARα in CD5(+) Daudi cells increased both their expression of immunosuppressive factors (that is, interleukin (IL)10 and phospho-STAT3) and resistance to metabolic and cytotoxic stressors. In contrast, marked downregulation of PPARα expression accompanied immunogenic death of proliferating CLL cells. The PPARα antagonist MK886 killed circulating CLL cells directly, caused proliferating CLL cells to enter an immunogenic death pathway and cleared CLL xenografts from immunodeficient mice. These results suggest that PPARα is a biological mediator of CLL and MK886 is a clinically relevant agent with activity against CLL.
Key Points• Glucocorticoids downregulate PKM2 and metabolism in CLL cells, impairing access to bioenergetic programs needed to repair cell damage.• PPARa and fatty acid oxidation antagonists potentiate the cytotoxic effects of glucocorticoids.High-dose glucocorticoids (GCs) can be a useful treatment for aggressive forms of chronic lymphocytic leukemia (CLL). However, their mechanism of action is not well understood, and resistance to GCs is inevitable. In a minimal, serum-free culture system, the synthetic GC dexamethasone (DEX) was found to decrease the metabolic activity of CLL cells, indicated by down-regulation of pyruvate kinase M2 (PKM2) expression and activity, decreased levels of pyruvate and its metabolites, and loss of mitochondrial membrane potential. This metabolic restriction was associated with decreased size and death of some of the tumor cells in the population. Concomitant plasma membrane damage increased killing of CLL cells by DEX. However, the nuclear receptor peroxisome proliferator activated receptor a (PPARa), which regulates fatty acid oxidation, was also increased by DEX, and adipocyte-derived lipids, lipoproteins, and propionic acid protected CLL cells from DEX. PPARa and fatty acid oxidation enzyme inhibitors increased DEX-mediated killing of CLL cells in vitro and clearance of CLL xenografts in vivo. These findings suggest that GCs prevent tumor cells from generating the energy needed to repair membrane damage, fatty acid oxidation is a mechanism of resistance to GC-mediated cytotoxicity, and PPARa inhibition is a strategy to improve the therapeutic efficacy of GCs. (Blood. 2013;122(6):969-980)
Nine rhesus macaques in groups of three received a single dose of the injectable progestin-based contraceptive Depo-Provera 5 weeks prior to challenge intravaginally with varying doses of a mixture of the pathogenic CXCR4 (X4)-SHIV(SF33A) and CCR5 (R5)-SHIV(SF162P3) isolates. As controls, seven Depo-naive animals were inoculated once with a high-dose of the mixed inoculum. Irrespective of inoculum dose, acute viremia was higher in the Depo-treated than in the Depo-naive animals. Further, genetic complexity of the replicating virus was greater and replication of the X4 virus was favored in dually infected animals treated with Depo-Provera. Analysis of cellular immune responses revealed slower response rates in virus-specific IFN-gamma production to SIV Gag in the Depo-treated macaques. The immunosuppressive effect of Depo-Provera on mounting an antiviral cellular immune response may account for the increase viral burden and diversity, and the predominance of X4 virus replication in SHIV infected macaques that were administered the progestin-based contraceptive.
; and the Pancreas Cancer Population Outcomes Research Group IMPORTANCE Postoperative morbidity associated with pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PA) remains as high as 70%. However, to our knowledge, few studies have examined quality of life in this patient population. OBJECTIVE To identify symptom burden and trajectories and factors associated with high symptom burden following PD for PA. DESIGN, SETTING, AND PARTICIPANTS This population-based cohort study of patients undergoing PD for PA diagnosed between 2009 and 2015 linked population-level administrative health care data to routinely prospectively collected Edmonton Symptom Assessment System (ESAS) scores from 2009 to 2015, with a data analysis undertaken in 2018. EXPOSURES Baseline characteristics, including age, sex, income quintile, rurality, immigration status, and comorbidity burden, as well as treatment characteristics, including year of surgery and receipt of chemotherapy. MAIN OUTCOME AND MEASURES The outcome of interest was moderate to severe symptoms (defined as ESAS Ն4) for anxiety, depression, drowsiness, lack of appetite, nausea, pain, shortness of breath, tiredness, and impaired well-being. The monthly prevalence of moderate to severe symptoms was presented graphically for each symptom. Multivariable regression models identified factors associated with the reporting of moderate to severe symptoms. RESULTS We analyzed 6058 individual symptom assessments among 615 patients with PA who underwent resection (285 women [46.3%]) with ESAS data. Tiredness (443 [72%]), impaired well-being (418 [68%]), and lack of appetite (400 [65%]) were most commonly reported as moderate to severe. The proportion of patients with moderate to severe symptoms was highest immediately after surgery (range, 14%-66% per symptom) and decreased over time, stabilizing around 3 months (range, 8%-42% per symptom). Female sex, higher comorbidity, and lower income were associated with a higher risk of reporting moderate to severe symptoms. Receipt of adjuvant chemotherapy was not associated with the risk of moderate to severe symptoms. CONCLUSIONS AND RELEVANCE There is a high prevalence of symptoms following PD for PA, with improvement over the first 3 months following surgery. In what to our knowledge is the largest cohort reporting on symptom burden for this population, we have identified factors associated with symptom severity. These findings will aid in managing patients' perioperative expectations and designing strategies to improve targeted symptom management.
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