Cholesterol is a critical component of membrane bilayers where it plays key structural and functional roles by regulating the activity of diverse signaling platforms and pathways. Particularly ...enriched in brain, cholesterol homeostasis in this organ is singular with respect to other tissues and exhibits a heterogeneous regulation in distinct brain cell populations. Due to the key role of cholesterol in brain physiology and function, alterations in cholesterol homeostasis and levels have been linked to brain diseases and neurodegeneration. In the case of Alzheimer disease (AD), however, this association remains unclear with evidence indicating that either increased or decreased total brain cholesterol levels contribute to this major neurodegenerative disease. Here, rather than analyzing the role of total cholesterol levels in neurodegeneration, we focus on the contribution of intracellular cholesterol pools, particularly in endolysosomes and mitochondria through its trafficking via specialized membrane domains delineated by the contacts between endoplasmic reticulum and mitochondria, in the onset of prevalent neurodegenerative diseases such as AD, Parkinson disease, and Huntington disease as well as in lysosomal disorders like Niemann-Pick type C disease. We dissect molecular events associated with intracellular cholesterol accumulation, especially in mitochondria, an event that results in impaired mitochondrial antioxidant defense and function. A better understanding of the mechanisms involved in the distribution of cholesterol in intracellular compartments may shed light on the role of cholesterol homeostasis disruption in neurodegeneration and may pave the way for specific intervention opportunities.
Chronic lymphocytic leukemia (CLL) is a B lymphoid malignancy highly dependent on the microenvironment. Despite new targeted therapies such as ibrutinib and venetoclax, disease progression and ...relapse remain an issue. CLL cell interactions with the supportive tissue microenvironment play a critical role in disease pathogenesis. We used a platform for drug discovery based on systems biology and artificial intelligence, to identify drugs targeting key proteins described to have a role in the microenvironment. The selected compounds were screened in CLL cell lines in the presence of stromal cells to mimic the microenvironment and validated the best candidates in primary CLL cells. Our results showed that the commercial drug simvastatin was the most effective and selective out of the tested compounds. Simvastatin decreased CLL cell survival and proliferation as well as cell adhesion. Importantly, this drug enhanced the antitumor effect of venetoclax and ibrutinib. We proposed that systems biology approaches combined with pharmacological screening could help to find new drugs for CLL treatment and to predict new combinations with current therapies. Our results highlight the possibility of repurposing widely used drugs such as statins to target the microenvironment and to improve the efficacy of ibrutinib or venetoclax in CLL cells.
NOTCH1 gene mutations in mantle cell lymphoma (MCL) have been described in about 5-10% of cases and are associated with significantly shorter survival rates. The present study aimed to investigate ...the biological impact of this mutation in MCL and its potential as a therapeutic target.
Activation of Notch1 signaling upon ligand-stimulation and inhibitory effects of the monoclonal anti-Notch1 antibody OMP-52M51 in NOTCH1-mutated and -unmutated MCL cells were assessed by Western Blot and gene expression profiling. Effects of OMP-52M51 treatment on tumor cell migration and tumor angiogenesis were evaluated with chemotaxis and HUVEC tube formation assays. The expression of Delta-like ligand 4 (DLL4) in MCL lymph nodes was analyzed by immunofluorescence staining and confocal microscopy. A MCL mouse model was used to assess the activity of OMP-52M51 in vivo.
Notch1 expression can be effectively stimulated in NOTCH1-mutated Mino cells by DLL4, whereas in the NOTCH1-unmutated cell line JeKo-1, less effect was observed upon any ligand-stimulation. DLL4 was expressed by histiocytes in both, NOTCH1-mutated and -unmutated MCL lymph nodes. Treatment of NOTCH1-mutated MCL cells with the monoclonal anti-Notch1 antibody OMP-52M51 effectively prevented DLL4-dependent activation of Notch1 and suppressed the induction of numerous direct Notch target genes involved in lymphoid biology, lymphomagenesis and disease progression. Importantly, in lymph nodes from primary MCL cases with NOTCH1/2 mutations, we detected an upregulation of the same gene sets as observed in DLL4-stimulated Mino cells. Furthermore, DLL4 stimulation of NOTCH1-mutated Mino cells enhanced tumor cell migration and angiogenesis, which could be abolished by treatment with OMP-52M51. Importantly, the effects observed were specific for NOTCH1-mutated cells as they did not occur in the NOTCH1-wt cell line JeKo-1. Finally, we confirmed the potential activity of OMP-52M51 to inhibit DLL4-induced Notch1-Signaling in vivo in a xenograft mouse model of MCL.
DLL4 effectively stimulates Notch1 signaling in NOTCH1-mutated MCL and is expressed by the microenvironment in MCL lymph nodes. Our results indicate that specific inhibition of the Notch1-ligand-receptor interaction might provide a therapeutic alternative for a subset of MCL patients.
In Colombia, cancer incidence is increasing, as is the demand for end-of-life care. Understanding how patients who die from cancer experience this phase will allow the identification of factors ...associated with greater suffering and actions to improve end-of-life care. We aimed to explore associations between the level of suffering of patients who died from cancer and were cared for in three Colombian hospitals with patient, tumor, treatment, and care characteristics and provided information.
Data on the last week of life and level of suffering were collected through proxies: Bereaved caregivers of patients who died from cancer in three participating Colombian hospitals. Bereaved caregivers participated in a phone interview and answered a series of questions regarding the last week of the patient's life. An ordinal logistic regression model explored the relationship between the level of suffering reported by bereaved caregivers with the patient's demographic and clinical characteristics, the bereaved caregivers, and the care received. Multivariate analyses were adjusted for place of death, treatments to prolong of life, prolongation of life during the dying process, suffering due to prolongation of life, type of cancer, age, if patient had partner, rural/urban residence of patient, importance of religion for the caregiver, caregivers´ relationship with the patient, and co-living with the patient.
A total of 174 interviews were included. Median age of the deceased patients was 64 years (IQR 52-72 years), and 93 patients were women (53.4%). Most caregivers had rated the level of suffering of their relative as "moderately to extremely" (n = 139, 80%). In multivariate analyses, factors associated with a higher level of suffering were: unclear information about the treatment and the process before death Odds Ratio (OR) 2.26 (90% CI 1.21-4.19), outpatient palliative care versus home care OR 3.05 (90% CI 1.05-8.88), procedures inconsistent with the patient's wishes OR 2.92 (90% CI 1.28-6.70), and a younger age (18-44 years) at death versus the oldest age group (75-93 years) OR 3.80 (90% CI 1.33-10.84, p = 0.04).
End-of-life care for cancer patients should be aligned as much as possible with patients´ wishes, needs, and capacities. A better dialogue between doctors, family members, and patients is necessary to achieve this.
Follicular lymphoma (FL), the most common indolent non-Hodgkin lymphoma, constitutes a paradigm of immune tumor microenvironment (TME) contribution to disease onset, progression, and heterogenous ...clinical outcome. Here we present the first FL-Patient Derived Lymphoma Spheroid (FL-PDLS), including fundamental immune actors and features of TME in FL lymph nodes (LNs). FL-PDLS is organized in disc-shaped 3D structures composed of proliferating B and T cells, together with macrophages with an intermediate M1/M2 phenotype. FL-PDLS recapitulates the most relevant B-cell transcriptional pathways present in FL-LN (proliferation, epigenetic regulation, mTOR, adaptive immune system, among others). The T cell compartment in the FL-PDLS preserves CD4 subsets (follicular helper, regulatory, and follicular regulatory), also encompassing the spectrum of activation/exhaustion phenotypes in CD4 and CD8 populations. Moreover, this system is suitable for chemo and immunotherapy testing, recapitulating results obtained in the clinic. FL-PDLS allowed uncovering that soluble galectin-9 limits rituximab, rituximab, plus nivolumab/TIM-3 antitumoral activities. Blocking galectin-9 improves rituximab efficacy, highlighting galectin-9 as a novel immunotherapeutic target in FL. In conclusion, FL-PDLS maintains the crosstalk between malignant B cells and the immune LN-TME and constitutes a robust and multiplexed pre-clinical tool to perform drug screening in a patient-derived system, advancing toward personalized therapeutic approaches.
Abstract
Background
Cancer patients’ end-of-life care may involve complex decision-making processes. Colombia has legislation regarding provision of and access to palliative care and is the only ...Latin American country with regulation regarding euthanasia. We describe medical end-of-life decision-making practices among cancer patients in three Colombian hospitals.
Methods
Cancer patients who were at the end-of-life and attended in participating hospitals were identified. When these patients deceased, their attending physician was invited to participate. Attending physicians of 261 cancer patients (out of 348 identified) accepted the invitation and answered a questionnaire regarding end-of-life decisions: a.) decisions regarding the withdrawal or withholding of potentially life-prolonging medical treatments, b.) intensifying measures to alleviate pain or other symptoms with hastening of death as a potential side effect, and c.) the administration, supply or prescription of drugs with an explicit intention to hasten death. For each question addressing the first two decision types, we asked if the decision was fully or partially made with the intention or consideration that it may hasten the patient’s death.
Results
Decisions to withdraw potentially life-prolonging treatment were made for 112 (43%) patients, 16 of them (14%) with an intention to hasten death. For 198 patients (76%) there had been some decision to not initiate potentially life-prolonging treatment. Twenty-three percent of patients received palliative sedation, 97% of all patients received opioids.
Six patients (2%) explicitly requested to actively hasten their death, for two of them their wish was fulfilled. In another six patients, medications were used with the explicit intention to hasten death without their explicit request. In 44% (
n
= 114) of all cases, physicians did not know if their patient had any advance care directives, 26% (
n
= 38) of physicians had spoken to the patient regarding the possibility of certain treatment decisions to hasten death where this applied.
Conclusions
Decisions concerning the end of life were common for patients with cancer in three Colombian hospitals, including euthanasia and palliative sedation. Physicians and patients often fail to communicate about advance care directives and potentially life-shortening effects of treatment decisions. Specific end-of-life procedures, patients’ wishes, and availability of palliative care should be further investigated.
Microenvironment contributes to follicular lymphoma (FL) pathogenesis and impacts survival with macrophages playing a controversial role. In the present study, using FL primary samples and HK ...follicular dendritic cells (FDC) to mimic the germinal center, together with mouse models, we have analyzed the three-way crosstalk of FL-FDC-macrophages and derived therapeutic opportunities. Ex vivo primary FL-FDC co-cultures (n = 19) and in vivo mouse co-xenografts demonstrated that FL-FDC crosstalk favors tumor growth and, via the secretion of CCL2 and CSF-1, promotes monocyte recruitment, differentiation, and polarization towards an M2-like protumoral phenotype. Moreover, FL-M2 co-cultures displayed enhanced angiogenesis, dissemination, and immunosuppression. Analysis of the CSF-1/CSF-1R pathway uncovered that CSF-1 was significantly higher in serum from grade 3A FL patients, and that high CSF-1R expression in FL biopsies correlated with grade 3A, reduced overall survival and risk of transformation. Furthermore, CSF-1R inhibition with pexidartinib (PLX3397) preferentially affected M2-macrophage viability and polarization program disrupting FL-M2 positive crosstalk. In vivo CSF1-R inhibition caused M2 reduction and repolarization towards M1 macrophages and antitumor effect cooperating with anti-CD20 rituximab. In summary, these results support the role of macrophages in FL pathogenesis and indicate that CSF-1R may be a relevant prognostic factor and a novel therapeutic target cooperating with anti-CD20 immunotherapy.
Abnormal cholesterol metabolism is linked to many neurodegenerative disorders. Here, we present a protocol for the production of a recombinant protein consisting of a Glutathione-S-Transferase tag ...fused with the Perfringolysin O (PFO). The GST-PFO tag enables analysis of the localization of cholesterol in subcellular membranes of human and mice brain and liver tissues. We have used this approach for samples from Niemann-Pick type C disease and non-alcoholic steatohepatitis models. The construct may also have applications for the diagnosis of cholesterol-accumulating disorders.
For complete details on the use and execution of this protocol, please refer to Kwiatkowska et al. (2014).
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•Protocol for producing a recombinant protein for tracing the localization of cholesterol•Recombinant protein can be combined with co-immunofluorescence experiments•Optimized approach for membrane cholesterol labeling in brain and liver tissue•Potential applications for the diagnosis of cholesterol-accumulating disorders
Abnormal cholesterol metabolism is linked to many neurodegenerative disorders. Here, we present a protocol for the production of a recombinant protein consisting of a Glutathione-S-Transferase tag fused with the Perfringolysin O (PFO). The GST-PFO tag enables analysis of the localization of cholesterol in subcellular membranes of human and mice brain and liver tissues. We have used this approach for samples from Niemann-Pick type C disease and non-alcoholic steatohepatitis models. The construct may also have applications for the diagnosis of cholesterol-accumulating disorders.
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