Enantioselective Approach for Expanding the Three-Dimensional Space of Tetrahydroquinoline to Develop BET Bromodomain Inhibitors.

The pharmaceutical industry has a pervasive need for chiral specific molecules with optimal affinity for their biological targets. However, the mass production of such compounds is currently limited by conventional chemical routes, that are costly and have an environmental impact. Here, we propose an easy access to obtain new tetrahydroquinolines, a motif found in many bioactive compounds, that is rapid and cost effective. Starting from simple raw materials, the procedure uses a proline-catalyzed Mannich reaction followed by the addition of BF3 ⋅ OEt2 , which generates a highly electrophilic aza-ortho-quinone methide intermediate capable of reacting with different nucleophiles to form the diversely functionalized tetrahydroquinoline. Moreover, this enantioselective one-pot process provides access for the first time to tetrahydroquinolines with a cis-2,3 and trans-3,4 configuration. As proof of concept, we demonstrate that a three-step reaction sequence, from simple and inexpensive starting compounds and catalysts, can generate a BD2-selective BET bromodomain inhibitor with anti-inflammatory effect.

Ofatumumab treatment for nephrotic syndrome recurrence after pediatric renal transplantation.

BACKGROUND: Relapsing nephrotic syndrome (NS) after transplantation can be a challenge to treat. The result of the consequent long-lasting proteinuria is the loss of the graft. Disease recurrence after renal transplantation occurs in around half of cases, and the efficacy of therapeutic strategies is often limited. Recently, ofatumumab, a second-generation and fully human anti-CD20 monoclonal antibody, has been shown to be effective in severe situations. METHODS: We retrospectively collected data from the medical records of children with recurrence of NS after renal transplantation treated with ofatumumab in France, after failure of previous treatments. RESULTS: Six patients were included in this study in five centers with a median duration of follow-up of 10.5 months. Two different ofatumumab regimens were administered. The primary outcome was proteinuria at 6 months after the last dose of ofatumumab. No patient achieved a complete remission, 3/6 had a partial remission, and 3/6 had no response to ofatumumab. Four patients exhibited a minor allergic reaction with the first infusion. One patient died of infection, as a consequence of multiple factors. No malignancies were observed; however, the time of follow-up was not sufficient to see such disease. CONCLUSIONS: Altogether, these results suggest ofatumumab has a poor efficacy in treating recurrence of NS after renal transplantation. However, it could be discussed in multidrug-resistant refractory NS, but infectious complications and overimmunosuppression have to be balanced. There is a need for further studies to confirm these findings and safety and to determine a standardized protocol in this indication.

Aryl Hydrocarbon Receptor Activation and Tissue Factor Induction by Fluid Shear Stress and Indoxyl Sulfate in Endothelial Cells.

Endogenous agonists of the transcription factor aryl hydrocarbon receptor (AHR) such as the indolic uremic toxin, indoxyl sulfate (IS), accumulate in patients with chronic kidney disease. AHR activation by indolic toxins has prothrombotic effects on the endothelium, especially via tissue factor (TF) induction. In contrast, physiological AHR activation by laminar shear stress (SS) is atheroprotective. We studied the activation of AHR and the regulation of TF by IS in cultured human umbilical vein endothelial cells subjected to laminar fluid SS (5 dynes/cm2). SS and IS markedly increased the expression of AHR target genes PTGS2 (encoding for COX2), AHRR, CYP1A1, and CYP1B1, as well as F3 (encoding for TF), in an AHR-dependent way. IS amplified SS-induced TF mRNA and protein expression and upregulation of AHR target genes. Interestingly, tyrosine kinase inhibition by genistein decreased SS- but not IS-induced TF expression. Finally, the increase in TF expression induced by laminar SS was not associated with increased TF activity. In contrast, IS increased TF activity, even under antithrombotic SS conditions. In conclusion, IS and SS induce AHR activation and AHR-dependent TF upregulation by different mechanisms. Impairment of the antithrombotic properties of shear stressed endothelium by toxic AHR agonists could favor cardiovascular diseases in CKD.

Is there utility for fluorine-18-fluorodeoxyglucose positron-emission tomography scan before surgery in breast cancer? A 15-year overall survival analysis.

BACKGROUND: The prognostic value of preoperative fluorine-18-fluorodeoxyglucose positron-emission tomography (18F-FDG PET) scan for determining overall survival (OS) in breast cancer (BC) patients is controversial. AIM: To evaluate the OS predictive value of preoperative PET positivity after 15 years. METHODS: We performed a retrospective search of the Universitair Ziekenhuis Brussel patient database for nonmetastatic patients who underwent preoperative PET between 2002-2008. PET positivity was determined by anatomical region of interest (AROI) findings for breast and axillary, sternal, and distant sites. The prognostic role of PET was examined as a qualitative binary factor (positive vs negative status) and as a continuous variable [maximum standard uptake value (SUVmax)] in multivariate survival analyses using Cox proportional hazards models. Among the 104 identified patients who received PET, 36 were further analyzed for the SUVmax in the AROI. RESULTS: Poor OS within the 15-year study period was predicted by PET-positive status for axillary (P = 0.033), sternal (P = 0.033), and combined PET-axillary/sternal (P = 0.008) nodes. Poor disease-free survival was associated with PET-positive axillary status (P = 0.040) and combined axillary/sternal status (P = 0.023). Cox models confirmed the long-term prognostic value of combined PET-axillary/sternal status [hazard ratio (HR): 3.08, 95% confidence interval: 1.42-6.69]. SUVmax of ipsilateral breast and axilla as continuous covariates were significant predictors of long-term OS with HRs of 1.25 (P = 0.048) and 1.54 (P = 0.029), corresponding to relative increase in the risk of death of 25% and 54% per SUVmax unit, respectively. In addition, the ratio of the ipsilateral axillary SUVmax over the contralateral axillary SUVmax was the most significant OS predictor (P = 0.027), with 1.94 HR, indicating a two-fold relative increase of mortality risk. CONCLUSION: Preoperative PET is valuable for prediction of long-term survival. Ipsilateral axillary SUVmax ratio over the uninvolved side represents a new prognostic finding that warrants further investigation.

Targeted Alpha Particle Therapy Remodels the Tumor Microenvironment and Improves Efficacy of Immunotherapy.

PURPOSE: The tumor microenvironment (TME) can severely impair immunotherapy efficacy by repressing the immune system. In a multiple myeloma (MM) murine model, we investigated the impact of targeted alpha particle therapy (TAT) on the immune TME. TAT was combined with an adoptive cell transfer of CD8 T cells (ACT), and the mechanisms of action of this combination were assessed at the tumor site. METHODS AND MATERIALS: This combination treatment was conducted in a syngeneic MM murine model grafted subcutaneously. TAT was delivered by intravenous injection of a bismuth-213 radiolabeled anti-CD138 antibody. To strengthen antitumor immune response, TAT was combined with an ACT of tumor-specific CD8+ OT-1 T-cells. The tumors were collected and the immune TME analyzed by flow cytometry, immunohistochemistry, and ex vivo T-cell motility assay on tumor slices. The chemokine and cytokine productions were also assessed by quantitative reverse transcription polymerase chain reaction. RESULTS: Tumor-specific CD8+ OT-1 T cells infiltrated the tumors after ACT. However, only treatment with TAT resulted in regulatory CD4 T-cell drop and transient increased production of interleukin-2, CCL-5, and interferon-γ within the tumor. Moreover, OT-1 T-cell recruitment and motility were increased on tumor slices from TAT-treated mice, as observed via ex vivo time lapse, contributing to a more homogeneous distribution of OT-1 T cells in the tumor. Subsequently, the tumor cells increased PD-L1 expression, antitumor cytokine production decreased, and OT-1 T-cells overexpressed exhaustion markers, suggesting an exhaustion of the immune response. CONCLUSION: Combining TAT and ACT seems to transiently remodel the cold TME, improving ACT efficiency. The immune response then leads to the establishment of other tumor cell resistance mechanisms.

Anti-Tumor Efficacy of PD-L1 Targeted Alpha-Particle Therapy in a Human Melanoma Xenograft Model.

PD-L1 (programmed death-ligand 1, B7-H1, CD274), the ligand for PD-1 inhibitory receptor, is expressed on various tumors, and its expression is correlated with a poor prognosis in melanoma. Anti-PD-L1 mAbs have been developed along with anti-CTLA-4 and anti-PD-1 antibodies for immune checkpoint inhibitor (ICI) therapy, and anti-PD-1 mAbs are now used as first line treatment in melanoma. However, many patients do not respond to ICI therapies, and therefore new treatment alternatives should be developed. Because of its expression on the tumor cells and on immunosuppressive cells within the tumor microenvironment, PD-L1 represents an interesting target for targeted alpha-particle therapy (TAT). We developed a TAT approach in a human melanoma xenograft model that stably expresses PD-L1 using a 213Bi-anti-human-PD-L1 mAb. Unlike treatment with unlabeled anti-human-PD-L1 mAb, TAT targeting PD-L1 significantly delayed melanoma tumor growth and improved animal survival. A slight decrease in platelets was observed, but no toxicity on red blood cells, bone marrow, liver or kidney was induced. Anti-tumor efficacy was associated with specific tumor targeting since no therapeutic effect was observed in animals bearing PD-L1 negative melanoma tumors. This study demonstrates that anti-PD-L1 antibodies may be used efficiently for TAT treatment in melanoma.

Breast cancer preoperative 18FDG-PET, overall survival prognostic separation compared with the lymph node ratio.

PURPOSE: To evaluate the overall survival prognostic value of preoperative 18F-fluorodeoxyglucose positron emission tomography (PET) in breast cancer, as compared with the lymph node ratio (LNR). METHODS: Data were abstracted at a median follow-up 14.7 years from a retrospective cohort of 104 patients who underwent PET imaging before curative surgery. PET-Axillary|Sternal was classified as PET-positive if hypermetabolism was visualized in ipsilateral nodal axillary and/or sternal region, else as PET-negative. The differences of 15 years restricted mean survival time ∆RMST according to PET and LNR were computed from Kaplan-Meier overall survival. The effect of PET and other patients' characteristics was analyzed through rankit normalization, which provides with Cox regression the Royston-Sauerbrei D measure of separation to compare the characteristics (0 indicating no prognostic value). Multivariate analysis of the normalized characteristics used stepwise selection with the Akaike information criterion. RESULTS: In Kaplan-Meier analysis, LNR > 0.20 versus ≤ 0.20 showed ∆RMST = 3.4 years, P = 0.003. PET-Axillary|Sternal positivity versus PET-negative showed a ∆RMST = 2.6 years, P = 0.008. In Cox univariate analyses, LNR appeared as topmost prognostic separator, D = 1.50, P < 0.001. PET ranked below but was also highly significant, D = 1.02, P = 0.009. In multivariate analyses, LNR and PET-Axillary|Sternal were colinear and mutually exclusive. PET-Axillary|Sternal improved as prognosticator in a model excluding lymph nodes, yielding a normalized hazard ratio of 2.44, P = 0.062. CONCLUSION: Pathological lymph node assessment remains the gold standard of prognosis. However, PET appears as a valuable surrogate in univariate analysis at 15-year follow-up. There was a trend towards significance in multivariate analysis that warrants further investigation.

Cell Tracking in Cancer Immunotherapy.

The impressive development of cancer immunotherapy in the last few years originates from a more precise understanding of control mechanisms in the immune system leading to the discovery of new targets and new therapeutic tools. Since different stages of disease progression elicit different local and systemic inflammatory responses, the ability to longitudinally interrogate the migration and expansion of immune cells throughout the whole body will greatly facilitate disease characterization and guide selection of appropriate treatment regiments. While using radiolabeled white blood cells to detect inflammatory lesions has been a classical nuclear medicine technique for years, new non-invasive methods for monitoring the distribution and migration of biologically active cells in living organisms have emerged. They are designed to improve detection sensitivity and allow for a better preservation of cell activity and integrity. These methods include the monitoring of therapeutic cells but also of all cells related to a specific disease or therapeutic approach. Labeling of therapeutic cells for imaging may be performed in vitro, with some limitations on sensitivity and duration of observation. Alternatively, in vivo cell tracking may be performed by genetically engineering cells or mice so that may be revealed through imaging. In addition, SPECT or PET imaging based on monoclonal antibodies has been used to detect tumors in the human body for years. They may be used to detect and quantify the presence of specific cells within cancer lesions. These methods have been the object of several recent reviews that have concentrated on technical aspects, stressing the differences between direct and indirect labeling. They are briefly described here by distinguishing ex vivo (labeling cells with paramagnetic, radioactive, or fluorescent tracers) and in vivo (in vivo capture of injected radioactive, fluorescent or luminescent tracers, or by using labeled antibodies, ligands, or pre-targeted clickable substrates) imaging methods. This review focuses on cell tracking in specific therapeutic applications, namely cell therapy, and particularly CAR (Chimeric Antigen Receptor) T-cell therapy, which is a fast-growing research field with various therapeutic indications. The potential impact of imaging on the progress of these new therapeutic modalities is discussed.

[Beware, polyarteritis nodosa still exists in nephrology!] / Attention, la périartérite noueuse existe encore en néphrologie !

Renal involvement of systemic vasculitides is an emergency in nephrology. Although it has become very rare, the diagnosis of polyarteritis nodosa must be considered in some patients. A 70-year-old patient, previously healthy, presented with acute renal failure and malignant hypertension and abundant albuminuria. Subcutaneous nodule, orchitis and mononeuritis appeared subsequently. The search for auto-immunity or viral infection was negative. Markers of thrombotic microangiopathy, present initially, resolved after blood pressure control. After a renal computed tomography with contrast medium injection was considered normal, without any micro-aneurysm, a renal biopsy was performed. It showed vascular lesions and glomerular ischemia. It was complicated by hemorragic shock after 36hours. The diagnosis of periarteritis nodosa was finally made after arterial angiography showed millimetric renal micro-aneurysms. In case of systemic vasculitis with renal involvement, periarteritis nodosa must be part of differential diagnosis, especially in case of malignant hypertension, subcutaneous nodosa and orchitis, and despite albuminuria. This implies the search for micro-aneurysms with arterial angiography, and the contraindication of renal biopsy, associated with a high risk of severe hemorrhage. Periarteritis nodosa still exists in nephrology, even without hepatitis B infection. The association of acute renal failure with medium vessel vasculitis, with negative ANCA, must alert the nephrologist and lead to arterial angiography not to renal biopsy.