Oncogenic senescence: a multi-functional perspective.

Cellular senescence is defined as an irreversible growth arrest with the acquisition of a distinctive secretome. The growth arrest is a potent anticancer mechanism whereas the secretome facilitates wound healing, tissue repair, and development. The senescence response has also become increasingly recognized as an important contributor to aging and age-related diseases, including cancer. Although oncogenic mutations are capable of inducing a beneficial senescence response that prevents the growth of premalignant cells and promotes cancer immune-surveillance, the secretome of senescent cells also includes factors with pro-tumorigenic properties. On June 23rd and 24th, 2016, the Division of Cancer Biology of the National Cancer Institute sponsored a workshop to discuss the complex role of cellular senescence in tumorigenesis with the goal to define the major challenges and opportunities within this important field of cancer research. Additionally, it was noted how the development of novel tools and technologies are required to accelerate research into a mechanistic understanding of senescent cells in carcinogenesis in order to overcome the current limitations in this exciting, yet ill-defined area

Deconstructing tumor heterogeneity: the stromal perspective.

Significant advances have been made towards understanding the role of immune cell-tumor interplay in either suppressing or promoting tumor growth, progression, and recurrence, however, the roles of additional stromal elements, cell types and/or cell states remain ill-defined. The overarching goal of this NCI-sponsored workshop was to highlight and integrate the critical functions of non-immune stromal components in regulating tumor heterogeneity and its impact on tumor initiation, progression, and resistance to therapy. The workshop explored the opposing roles of tumor supportive versus suppressive stroma and how cellular composition and function may be altered during disease progression. It also highlighted microenvironment-centered mechanisms dictating indolence or aggressiveness of early lesions and how spatial geography impacts stromal attributes and function. The prognostic and therapeutic implications as well as potential vulnerabilities within the heterogeneous tumor microenvironment were also discussed. These broad topics were included in this workshop as an effort to identify current challenges and knowledge gaps in the field

Oncogenic senescence: a multi-functional perspective.

Cellular senescence is defined as an irreversible growth arrest with the acquisition of a distinctive secretome. The growth arrest is a potent anticancer mechanism whereas the secretome facilitates wound healing, tissue repair, and development. The senescence response has also become increasingly recognized as an important contributor to aging and age-related diseases, including cancer. Although oncogenic mutations are capable of inducing a beneficial senescence response that prevents the growth of premalignant cells and promotes cancer immune-surveillance, the secretome of senescent cells also includes factors with pro-tumorigenic properties. On June 23rd and 24th, 2016, the Division of Cancer Biology of the National Cancer Institute sponsored a workshop to discuss the complex role of cellular senescence in tumorigenesis with the goal to define the major challenges and opportunities within this important field of cancer research. Additionally, it was noted how the development of novel tools and technologies are required to accelerate research into a mechanistic understanding of senescent cells in carcinogenesis in order to overcome the current limitations in this exciting, yet ill-defined area

The association between the comprehensive Epstein-Barr virus serological profile and endemic Burkitt lymphoma.

Background: The discovery of Epstein–Barr virus (EBV) in Burkitt lymphoma tumors represented the first link between a virus and cancer in humans, but the underlying role of this virus in endemic Burkitt lymphoma remains unclear. Nearly all children in Burkitt lymphoma–endemic areas are seropositive for EBV, but only a small percentage develop disease. Variation in EBV-directed immunity could be an explanatory cofactor. Methods: We examined serum from 150 Burkitt lymphoma cases and 150 controls using a protein microarray that measured IgG and IgA antibodies against 202 sequences across the entire EBV proteome. Variation in the EBV-directed antibody repertoire between Burkitt lymphoma cases and controls was assessed using unpaired t tests. ORs quantifying the association between anti-EBV IgG response tertiles and Burkitt lymphoma status were adjusted for age, sex, and study year. Results: Thirty-three anti-EBV IgG responses were elevated in Burkitt lymphoma cases compared with controls (P ≤ 0.0003). Burkitt lymphoma–associated IgG elevations were strongest for EBV proteins involved in viral replication and antiapoptotic signaling. Specifically, we observed ORs ≥4 for BMRF1 (early antigen), BBLF1 (tegument protein), BHRF1 (Bcl-2 homolog), BZLF1 (Zebra), BILF2 (glycoprotein), BLRF2 [viral capsid antigen (VCA)p23], BDLF4, and BFRF3 (VCAp18). Adjustment for malaria exposure and inheritance of the sickle cell variant did not alter associations. Conclusions: Our data suggest that the anti-EBV serologic profile in patients with Burkitt lymphoma is altered, with strong elevations in 33 of the measured anti-EBV IgG antibodies relative to disease-free children. Impact: The Burkitt lymphoma–specific signature included EBV-based markers relevant for viral replication and antiapoptotic activity, providing clues for future Burkitt lymphoma pathogenesis research

Plasma thrombospondin-1 is increased during acute sickle cell vaso-occlusive events and associated with acute chest syndrome, hydroxyurea therapy, and lower hemolytic rates

Platelets are activated in sickle cell disease (SCD), and particularly during vaso-occlusive episodes (VOE). Thrombospondin-1 (TSP1), a major secretory product of activated platelets, is increased in the circulation in VOE and binds to sickle red blood cells (RBC) promoting vascular adhesion. Thus, we hypothesized that TSP1 may represent a plasma biomarker of disease severity in SCD. We tested the plasma collected from patients in steady state (n = 27) and VOE (n = 14), as well as healthy controls (n = 17) at the University of Pittsburgh Medical Center (UPMC), and from patients in steady state enrolled in the walk-PHaSST clinical trial (n = 483). We found that TSP1 levels were increased in VOE in the UPMC cohort. Among steady-state patients at UPMC, TSP1 values correlated positively with lifetime history of acute chest syndrome (r = 0.72, P < 0.0001) and hemoglobin concentration (r = 0.49, P = 0.01), and negatively with markers of hemolysis, such as LDH (r = −0.50, P = 0.009). Analysis of the walk-PHaSST cohort also showed a positive association between TSP1 levels and hydroxyurea use (r = 0.14, P = 0.003), and confirmed the negative associations with the severity of hemolysis. Our results suggest that TSP1 levels are associated with more VOE, hydroxyurea use and lower rates of hemolysis. High TSP1 concentrations may indicate higher risk of the viscosity/vaso-occlusion phenotype of SCD

Plasma thrombospondin-1 is increased during acute sickle cell vaso-occlusive events and associated with acute chest syndrome, hydroxyurea therapy, and lower hemolytic rates

Platelets are activated in sickle cell disease (SCD), and particularly during vaso-occlusive episodes (VOE). Thrombospondin-1 (TSP1), a major secretory product of activated platelets, is increased in the circulation in VOE and binds to sickle red blood cells (RBC) promoting vascular adhesion. Thus, we hypothesized that TSP1 may represent a plasma biomarker of disease severity in SCD. We tested the plasma collected from patients in steady state (n = 27) and VOE (n = 14), as well as healthy controls (n = 17) at the University of Pittsburgh Medical Center (UPMC), and from patients in steady state enrolled in the walk-PHaSST clinical trial (n = 483). We found that TSP1 levels were increased in VOE in the UPMC cohort. Among steady-state patients at UPMC, TSP1 values correlated positively with lifetime history of acute chest syndrome (r = 0.72, P < 0.0001) and hemoglobin concentration (r = 0.49, P = 0.01), and negatively with markers of hemolysis, such as LDH (r = −0.50, P = 0.009). Analysis of the walk-PHaSST cohort also showed a positive association between TSP1 levels and hydroxyurea use (r = 0.14, P = 0.003), and confirmed the negative associations with the severity of hemolysis. Our results suggest that TSP1 levels are associated with more VOE, hydroxyurea use and lower rates of hemolysis. High TSP1 concentrations may indicate higher risk of the viscosity/vaso-occlusion phenotype of SCD

Behavioral factors and SARS-CoV-2 transmission heterogeneity within a household cohort in Costa Rica

Abstract Introduction Variability in household secondary attack rates and transmission risks factors of SARS-CoV-2 remain poorly understood. Methods We conducted a household transmission study of SARS-CoV-2 in Costa Rica, with SARS-CoV-2 index cases selected from a larger prospective cohort study and their household contacts were enrolled. A total of 719 household contacts of 304 household index cases were enrolled from November 21, 2020, through July 31, 2021. Blood specimens were collected from contacts within 30–60 days of index case diagnosis; and serum was tested for presence of spike and nucleocapsid SARS-CoV-2 IgG antibodies. Evidence of SARS-CoV-2 prior infections among household contacts was defined based on the presence of both spike and nucleocapsid antibodies. We fitted a chain binomial model to the serologic data, to account for exogenous community infection risk and potential multi-generational transmissions within the household. Results Overall seroprevalence was 53% (95% confidence interval (CI) 48–58%) among household contacts. The estimated household secondary attack rate is 34% (95% CI 5–75%). Mask wearing by the index case is associated with the household transmission risk reduction by 67% (adjusted odds ratio = 0.33 with 95% CI: 0.09–0.75) and not sharing bedroom with the index case is associated with the risk reduction of household transmission by 78% (adjusted odds ratio = 0.22 with 95% CI 0.10–0.41). The estimated distribution of household secondary attack rates is highly heterogeneous across index cases, with 30% of index cases being the source for 80% of secondary cases. Conclusions Modeling analysis suggests that behavioral factors are important drivers of the observed SARS-CoV-2 transmission heterogeneity within the household