300 research outputs found
Nuclear EGFR modulation of DNA repair
Overexpression of the epidermal growth factor receptor (EGFR) is associated with
resistance to chemotherapy and radiotherapy. EGFR involvement, in repair of radiation-induced
DNA damage, is mediated by association with the catalytic subunit of DNA
protein kinase (DNAPKcs). This study investigated the role of EGFR nuclear import,
and its association with DNAPKcs, on DNA repair following treatment either with
cisplatin or ionizing radiation (IR). EGFR- null murine NIH3T3 cells were transfected
with wild type or with mutated EGFR (mutations found in human cancers L858R,
EGFRvIII and mutations in the EGFR nuclear localization signal (NLS) sequence
NLS123, LNLS123). Comet assay analysis, which measures unhooking of cisplatin
crosslinks and repair of IR induced strand breaks, demonstrated that wtEGFR and
EGFRvIII completely repair cisplatin and IR induced DNA damage.
Immunoprecipitation studies show that repair is associated with the binding of both
wtEGFR and EGFRvIII to DNAPKcs, which increases by 2- fold 18 hours following
cisplatin treatment. Confocal analysis and proximity ligation assay indicated that this
association takes place both in the cytoplasm and in the nucleus resulting in a significant
increase of DNA-PK kinase activity. Intermediate levels of repair as shown by the
L858R construct with impaired nuclear localization demonstrated that EGFR kinase
activity is partially involved in repair but is not sufficient to determine EGFR nuclear
expression. EGFR-NLS mutants showed impaired nuclear localization and impaired
DNAPKcs association resulting in significant inhibition of DNA repair and downregulation
of DNA-PK kinase activity.
Our data suggest that EGFR nuclear localization is required for the modulation of
cisplatin and IR induced DNA damage repair. The EGFR-DNAPKcs binding is
triggered by cisplatin or IR and not by EGFR nuclear translocation per se.
Understanding mechanisms regulating EGFR subcellular distribution in relation to DNA
repair kinetics will be a critical determinant of improved molecular targeting and
response to therapy
Active Moderate-to-Severe Graves' Orbitopathy in a Patient With Type 2 Diabetes Mellitus and Vascular Complications
Background: Graves’ orbitopathy (GO) is the main extrathyroidal manifestation of
Graves’ disease (GD). Diabetes mellitus (DM) has been reported to be a risk factor in
patients with GO. Moreover, GO can be more frequent and severe in type 2 diabetes
patients. High doses of intravenous glucocorticoids represent the first line treatment of
moderate-to-severe and active GO according to the international guidelines. However,
this therapy is contraindicated in uncontrolled diabetes and in patients with increased
cardiovascular risk. Some anti-diabetic drugs can exacerbate GO. We reported the
clinical case of an active and moderate-to-severe GO in a patient with uncontrolled type
2 DM and vascular complications.
Case Report: A 61-years-old patient came to our ambulatory for a recurrence of
GD and a moderate-to-severe bilateral GO. The patient had uncontrolled type 2 DM
during insulin therapy and a history of micro and macrovascular complications. At the
physical examination, the clinical activity score was 5 and the severity of GO was
moderate-to-severe. A blood sample showed overt hyperthyroidism and the persistence
of anti-TSH receptor antibodies (TRAb) during treatment with methimazole. A computed
tomography scan showed a moderate-to-severe bilateral exophthalmos. We discuss the
benefit/risk of treatment of GO in our patient.
Conclusion: The available guidelines do not focus on the treatment of diabetic patients
with uncontrolled diabetes and severe vascular complications, therefore our patient
represents a difficult therapeutic challenge. The screening of thyroid function and the
evaluation of GO could be useful in diabetic patients with autoimmune thyroid disease to
perform a correct treatment of these disorders
Allergy in adolescent population (14-18 years) living in campania region (southern Italy). a multicenter study
Adolescents (Ad) constitute a difficult to manage population among individuals suffering from asthma. The aim of our study was to assess the prevalence, clinical characteristics and age of onset of allergic sensitization and clinical symptoms in a sample of atopic Ad living in the Campania region (Southern Italy). Sixteen Allergy units or Centers belonging to the Italian Association of Hospital and Territorial Allergologists (AAIITO, Campania region) participated in this cross-sectional study. A case report form (CRF) was specifically designed for this study and commercial allergen extracts used for screening SPTs were provided by ALK-AbellĂł Group (Milan, Italy). A total of 443 patients were examined (females, f 220, 49.6 %; males, m 223, 50.3%). Dust mites represent the most common sensitizing agents in allergic Ad living in Campania region (Dermatoph. pteronyssinus 67.4% and Dermatoph. farinae 66.5%), followed by Parietaria (58.9%), grasses (45.8%), Artemisia vulgaris (16.7%), Olea Europaea (32.2%), dog dander (17.1%), cat dander (20.0%), Alternaria alternata (8.1%), Cupressus sempervirens (4.9%), Betula pendula (4.7%), other allergens (19.4%). An interesting comparison has been made between clinical data of our Ad with data of elderly patients (E). The role of allergic sensitization is significantly higher in Ad compared to E. Dermatophagoides pteronyssinus is the first sensitizing allergen in Ad and the last in E. Parietaria constitutes the first sensitizing pollen both in Ad and E, the percentage of sensitization is higher in Ad. Another important difference is the higher prevalence of As, as only symptom, in E compared to Ad (19.7% versus 7.6%). In conclusion, our findings confirm the high prevalence and clinical significance of airway allergic sensitization in the adolescents living in Campania region
RIPK1-mediated immunogenic cell death promotes anti-tumour immunity against soft-tissue sarcoma.
Drugs that mobilise the immune system against cancer are dramatically improving care for many people. Dying cancer cells play an active role in inducing anti-tumour immunity but not every form of death can elicit an immune response. Moreover, resistance to apoptosis is a major problem in cancer treatment and disease control. While the term "immunogenic cell death" is not fully defined, activation of receptor-interacting serine/threonine-protein kinase 1 (RIPK1) can induce a type of death that mobilises the immune system against cancer. However, no clinical treatment protocols have yet been established that would harness the immunogenic potential of RIPK1. Here, we report the first pre-clinical application of an in vivo treatment protocol for soft-tissue sarcoma that directly engages RIPK1-mediated immunogenic cell death. We find that RIPK1-mediated cell death significantly improves local disease control, increases activation of CD8+ T cells as well as NK cells, and enhances the survival benefit of immune checkpoint blockade. Our findings warrant a clinical trial to assess the survival benefit of RIPK1-induced cell death in patients with advanced disease at limb extremities
The unconventional myosin CRINKLED and its mammalian orthologue MYO7A regulate caspases in their signalling roles
Caspases provide vital links in non-apoptotic regulatory networks controlling inflammation, compensatory proliferation, morphology and cell migration. How caspases are activated under non-apoptotic conditions and process a selective set of substrates without killing the cell remain enigmatic. Here we find that the Drosophila unconventional myosin CRINKLED (CK) selectively interacts with the initiator caspase DRONC and regulates some of its non-apoptotic functions. Loss of CK in the arista, border cells or proneural clusters of the wing imaginal discs affects DRONC-dependent patterning. Our data indicate that CK acts as substrate adaptor, recruiting SHAGGY46/GSK3-β to DRONC, thereby facilitating caspase-mediated cleavage and localized modulation of kinase activity. Similarly, the mammalian CK counterpart, MYO7A, binds to and impinges on CASPASE-8, revealing a new regulatory axis affecting receptor interacting protein kinase-1 (RIPK1)>CASPASE-8 signalling. Together, our results expose a conserved role for unconventional myosins in transducing caspase-dependent regulation of kinases, allowing them to take part in specific signalling events
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