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Last Modified, June 28, 2020
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The kinesin-like protein Pavarotti functions noncanonically to regulate actin dynamics

J Cell Biol

2020 Susan Parkhurst; Jeffrey Verboon; Mitsutoshi Nakamura; Clara Prentiss

Pavarotti, the Drosophila MKLP1 orthologue, is a kinesin-like protein that works with Tumbleweed (MgcRacGAP) as the centralspindlin complex. This complex is essential for cytokinesis, where it helps to organize the contractile actomyosin ring at the equator of dividing cells by activating the RhoGEF Pebble. Actomyosin rings also function as the driving force during cell wound repair. We previously showed that Tumbleweed and Pebble are required for the cell wound repair process. Here, we show that Pavarotti also functions during wound repair and confirm that while Pavarotti, Tumbleweed, and Pebble are all used during this cellular repair, each has a unique localization pattern and knockdown phenotype, demonstrating centralspindlin-independent functions. Surprisingly, we find that the classically microtubule-associated Pavarotti binds directly to actin in vitro and in vivo and has a noncanonical role directly regulating actin dynamics. Finally, we demonstrate that this actin regulation by Pavarotti is not specific to cellular wound repair but is also used in normal development.

Accumulation of long-chain fatty acids in the tumor microenvironment drives dysfunction in intrapancreatic CD8+ T cells

J Exp Med

2020 Philip Greenberg; Kristin Anderson; Breanna Bates

CD8+ T cells are master effectors of antitumor immunity, and their presence at tumor sites correlates with favorable outcomes. However, metabolic constraints imposed by the tumor microenvironment (TME) can dampen their ability to control tumor progression. We describe lipid accumulation in the TME areas of pancreatic ductal adenocarcinoma (PDA) populated by CD8+ T cells infiltrating both murine and human tumors. In this lipid-rich but otherwise nutrient-poor TME, access to using lipid metabolism becomes particularly valuable for sustaining cell functions. Here, we found that intrapancreatic CD8+ T cells progressively accumulate specific long-chain fatty acids (LCFAs), which, rather than provide a fuel source, impair their mitochondrial function and trigger major transcriptional reprogramming of pathways involved in lipid metabolism, with the subsequent reduction of fatty acid catabolism. In particular, intrapancreatic CD8+ T cells specifically exhibit down-regulation of the very-long-chain acyl-CoA dehydrogenase (VLCAD) enzyme, which exacerbates accumulation of LCFAs and very-long-chain fatty acids (VLCFAs) that mediate lipotoxicity. Metabolic reprogramming of tumor-specific T cells through enforced expression of ACADVL enabled enhanced intratumoral T cell survival and persistence in an engineered mouse model of PDA, overcoming one of the major hurdles to immunotherapy for PDA.

Phosphatidylinositol-3-Kinase Inhibition in Follicular Lymphoma

Hematol Oncol Clin North Am

2020 Ryan Lynch; Ajay Gopal

Chemoimmunotherapy is the standard frontline treatment for symptomatic or high tumor burden follicular lymphoma. Better understanding of the molecular mechanisms of lymphomagenesis has led to the development of drugs targeting these pathways. The phosphatidylinositol-3-kinase pathway is an important signaling pathway in B-cell lymphomas. Three drugs in this class have received FDA approval. We describe the efficacy and toxicities of phosphatidylinositol-3-kinase inhibitors. Response rates in highly refractory disease are high, demonstrate few long-term remissions, and have high long-term toxicity. Early data on dosing and combination strategies are promising and may change how we use these agents in the coming years.

The NK cell-cancer cycle: advances and new challenges in NK cell-based immunotherapies

Nat Immunol

2020 Kevin Barry

Natural killer (NK) cells belong to the innate immune system and contribute to protecting the host through killing of infected, foreign, stressed or transformed cells. Additionally, via cellular cross-talk, NK cells orchestrate antitumor immune responses. Hence, significant efforts have been undertaken to exploit the therapeutic properties of NK cells in cancer. Current strategies in preclinical and clinical development include adoptive transfer therapies, direct stimulation, recruitment of NK cells into the tumor microenvironment (TME), blockade of inhibitory receptors that limit NK cell functions, and therapeutic modulation of the TME to enhance antitumor NK cell function. In this Review, we introduce the NK cell-cancer cycle to highlight recent advances in NK cell biology and to discuss the progress and problems of NK cell-based cancer immunotherapies.

Recipient and donor genetic variants associated with mortality after allogeneic hematopoietic cell transplantation

Blood Adv

2020 Emily Hansen; John Hansen; Barry Storer; Paul Martin

Many studies have suggested that genetic variants in donors and recipients are associated with survival-related outcomes after allogeneic hematopoietic cell transplantation (HCT), but these results have not been confirmed. Therefore, the utility of testing genetic variants in donors and recipients for risk stratification or understanding mechanisms leading to mortality after HCT has not been established. We tested 122 recipient and donor candidate variants for association with nonrelapse mortality (NRM) and relapse mortality (RM) in a cohort of 2560 HCT recipients of European ancestry with related or unrelated donors. Associations discovered in this cohort were tested for replication in a separate cohort of 1710 HCT recipients. We found that the donor rs1051792 A allele in MICA was associated with a lower risk of NRM. Donor and recipient rs1051792 genotypes were highly correlated, making it statistically impossible to determine whether the donor or recipient genotype accounted for the association. Risks of grade 3 to 4 graft-versus-host disease (GVHD) and NRM in patients with grades 3 to 4 GVHD were lower with donor MICA-129Met but not with MICA-129Val, implicating MICA-129Met in the donor as an explanation for the decreased risk of NRM after HCT. Our analysis of candidate variants did not show any other association with NRM or RM. A genome-wide association study did not identify any other variants associated with NRM or RM.

Genome-Wide Association Study Meta-Analysis of Stroke in 22 000 Individuals of African Descent Identifies Novel Associations With Stroke

Stroke

2020 Jeffrey Haessler; Alex Reiner; Charles Kooperberg

BACKGROUND AND PURPOSE: Stroke is a complex disease with multiple genetic and environmental risk factors. Blacks endure a nearly 2-fold greater risk of stroke and are 2 to 3 more likely to die from stroke than European Americans. METHODS: The COMPASS (Consortium of Minority Population Genome-Wide Association Studies of Stroke) has conducted a genome-wide association meta-analysis of stroke in >22 000 individuals of African ancestry (3734 cases, 18 317 controls) from 13 cohorts. RESULTS: In meta-analyses, we identified one single nucleotide polymorphism (rs55931441) near the HNF1A gene that reached genome-wide significance (P=4.6210-8) and an additional 29 variants with suggestive evidence of association (P<110-6), representing 24 unique loci. For validation, a look-up analysis for a 100 kb region flanking the COMPASS single nucleotide polymorphism was performed in SiGN (Stroke Genetics Network) Europeans, SiGN Hispanics, and METASTROKE (Europeans). Using a stringent Bonferroni correction P value of 2.0810-3 (0.05/24 unique loci), we were able to validate associations at the HNF1A locus in both SiGN (P=8.1810-4) and METASTROKE (P=1.7210-3) European populations. Overall, 16 of 24 loci showed evidence for validation across multiple populations. Previous studies have reported associations between variants in the HNF1A gene and lipids, C-reactive protein, and risk of coronary artery disease and stroke. Suggestive associations with variants in the SFXN4 and TMEM108 genes represent potential novel ischemic stroke loci. CONCLUSIONS: These findings represent the most thorough investigation of genetic determinants of stroke in individuals of African descent, to date.

Cancer and Pregnancy: National Trends

Am J Perinatol

2020 Hilary Gammill; Vijayakrishna Gadi

OBJECTIVE: Cancer and pregnancy are likely increasing; however, updated estimates are needed to optimally address the unique needs of this patient population. The study aims to estimate the prevalence of cancer and cancer survivorship at delivery, to test the change in odds of cancer and cancer survivorship at delivery over the 10-year period, and to compare medical conditions, serious events, and obstetric complications between pregnancies with and without cancer at delivery. STUDY DESIGN: We conducted a retrospective analysis of the National Inpatient Sample (NIS), the largest all-payer inpatient health database in the United States. We identified delivery admissions from 2004 to 2013 with a concurrent diagnosis of cancer using International Classification of Disease, ninth revision (ICD-9) codes. Multivariable logistic regression was used to test the change in prevalence of concurrent cancer, cancer survivorship, and pregnancy and to compare outcomes between deliveries with and without cancer. All analyses were adjusted for NIS-provided population weights and strata. RESULTS: During the study period, the NIS represented a national estimate of 40,855,208 deliveries. The odds of cancer increased from 3.41/10,000 deliveries in 2004 to 4.33/10,000 in 2013. This trend was statistically significant, including after adjustment for maternal age (adjusted odds ratio [aOR]=1.03 [95% confidence interval (CI): 1.01-1.04]). Cancer survivorship at delivery increased significantly (aOR=1.07 [95% CI: 1.06-1.08]). Women with cancer more often experienced one or more of the following: death, ventilation, cardiac arrest, sepsis, or acute respiratory or renal failure during delivery (aOR for composite outcome 10.7 [95% CI: 6.6-17.2]), even after adjustment in a multivariable logistic regression model. CONCLUSION: The odds of cancer and cancer survivorship at delivery increased from 2004 to 2013, independent of maternal age. Women with cancer were more likely to experience medical or obstetric complications during their delivery compared with women without cancer. These findings highlight the importance of obstetric and oncologic clinical and research collaboration to improve patient care. KEY POINTS: The odds of cancer at delivery increased.. Women with cancer may have delivery complications.. Cancer survivorship at delivery increased..

Relationship Between Chronic Kidney Disease, Glucose Homeostasis, and Plasma Osteocalcin Carboxylation and Fragmentation

J Ren Nutr

2020 Mario Kratz

OBJECTIVE: Chronic kidney disease (CKD) is associated with reduced insulin sensitivity, through mechanisms that are not well understood. Low vitamin K intake and incomplete carboxylation of the vitamin K-dependent protein osteocalcin may promote insulin resistance. We assessed relationships of osteocalcin concentration, carboxylation, and fragmentation with CKD and glucose homeostasis in a cross-sectional study. METHODS: We included 87 participants without diabetes: 50 (27 female) with moderate to severe CKD (estimated glomerular filtration rate <60mL/min/1.73m2 not treated with dialysis) and 37 (17 female) healthy controls. Total osteocalcin was measured by immunoassay, and osteocalcin carboxylation and fragmentation status by liquid chromatography-electrospray ionization-based mass spectrometric immunoassay. Endpoints included glucose tolerance (based on 2-hour oral glucose tolerance test), insulin sensitivity (hyperinsulinemic-euglycemic clamp), and pancreatic beta-cell function (intravenous glucose tolerance test). RESULTS: The total plasma osteocalcin concentration was higher in the CKD group (mean [standard deviation] 102.9 [147.5]) than that in the control group (53.6 [51.1] ng/mL, P=.03), and more osteocalcin was circulating as fragments. The extent of osteocalcin carbocylation did not differ between individuals with and without CKD. Osteocalcin concentration, carboxylation, and fragmentation were not associated with any measure of glucose homeostasis in multivariable-adjusted analyses. CONCLUSIONS: In CKD, circulating osteocalcin concentrations are elevated, in part due to larger proportions of fragmented forms. However, osteocalcin carboxylation status is not significantly different between individuals with and without CKD. Our data also do not provide support for the hypothesis that differences in osteocalcin carboxylation may explain reduced insulin sensitivity in individuals with CKD.

Validity of university students' self-reported vaccination status after a meningococcal B outbreak

J Am Coll Health

2020 M. Elizabeth Halloran

After an outbreak of meningococcal B (MenB) disease at a university, we surveyed students regarding their vaccination status 2 months and 20 months after campus-led vaccination campaigns and compared students' self-report to vaccination records. Nearly all participants accurately reported the number of vaccine doses at both visits. Among those who received two doses of the vaccine, accurate recall of the timing of MenB vaccination was 85.7% (95% CI: 82.7-88.6) in the short term and 62.9% (95% CI: 56.0-69.8) in the long term. After the outbreak, only one-third reported feeling 'very confident' in their MenB disease and vaccine knowledge. Our findings suggest that the validity of self-reported vaccination status among university students in an outbreak setting is high, but that if the duration of protection is unknown and additional doses of vaccine may be needed, documented vaccination records may be preferred over self-report to assess timing of vaccine receipt.

Call for Papers: Expanding the Scale and Scope of Therapeutic Gene Editing

Mol Ther

2020 Hans-Peter Kiem

N/A

Last Modified, February 20, 2020