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mTOR inhibitors (mTOR-Is) may induce proteinuria in kidney transplant recipients through podocyte damage. However, the mechanism has only been partially defined. Total cell lysates and supernatants of immortalized human podocytes treated with different doses of everolimus (EVE) (10, 100, 200, and 500 nM) for 24 h were subjected to mass spectrometry-based proteomics. Support vector machine and partial least squares discriminant analysis were used for data analysis. The results were validated in urine samples from 28 kidney transplant recipients receiving EVE as part of their immunosuppressive therapy. We identified more than 7000 differentially expressed proteins involved in several pathways, including kinases, cell cycle regulation, epithelial–mesenchymal transition, and protein synthesis, according to gene ontology. Among these, after statistical analysis, 65 showed an expression level significantly and directly correlated with EVE dosage. Polo-Like Kinase 1 (PLK1) content was increased, whereas osteopontin (SPP1) content was reduced in podocytes and supernatants in a dose-dependent manner and significantly correlated with EVE dose (p < 0.0001, FDR < 5%). Similar results were obtained in the urine of kidney transplant patients. This study analyzed the impact of different doses of mTOR-Is on podocytes, helping to understand not only the biological basis of their therapeutic effects but also the possible mechanisms underlying proteinuria. [ABSTRACT FROM AUTHOR]

Kaposiform lymphangiomatosis (KLA) is a rare and complex lymphatic anomaly associated with substantial morbidity and mortality. It features diffuse and multifocal malformed lymphatic channels, often leading to diagnostic difficulties due to its uncommon occurrence and non-specific clinical presentation. This case report emphasizes the crucial role of expert radiologists in accurately diagnosing a challenging KLA case initially mistaken for a neoplasm.

mTOR inhibitors (mTOR-Is) may induce proteinuria in kidney transplant recipients through podocyte damage. However, the mechanism has only been partially defined. Total cell lysates and supernatants of immortalized human podocytes treated with different doses of everolimus (EVE) (10, 100, 200, and 500 nM) for 24 h were subjected to mass spectrometry-based proteomics. Support vector machine and partial least squares discriminant analysis were used for data analysis. The results were validated in urine samples from 28 kidney transplant recipients receiving EVE as part of their immunosuppressive therapy. We identified more than 7000 differentially expressed proteins involved in several pathways, including kinases, cell cycle regulation, epithelial–mesenchymal transition, and protein synthesis, according to gene ontology. Among these, after statistical analysis, 65 showed an expression level significantly and directly correlated with EVE dosage. Polo-Like Kinase 1 (PLK1) content was increased, whereas osteopontin (SPP1) content was reduced in podocytes and supernatants in a dose-dependent manner and significantly correlated with EVE dose (p < 0.0001, FDR < 5%). Similar results were obtained in the urine of kidney transplant patients. This study analyzed the impact of different doses of mTOR-Is on podocytes, helping to understand not only the biological basis of their therapeutic effects but also the possible mechanisms underlying proteinuria.

Background. Taking into account the literature data, the activation of the PI3K-AKT-mTOR cascade plays a role in the development of leiomyosarcoma (LMS), and the expression of markers of this signaling pathway in the tumor is associated with a more aggressive course of the disease. In addition, there is some data on the effective use of mTOR inhibitors in LMS. Aim. To study the frequency of expression of mTOR and phospho-mTOR markers in relapse of high-grade uterine LMS and to evaluate the effect of phospho-mTOR expression on the immediate and long-term results of the use of doxorubicin-containing chemotherapy regimens and the combination of gemcitabine + docetaxel. Materials and methods. The study included 31 patients with high-grade uterine LMS operated on for relapse. IHC was performed using mTOR and phospho-mTOR antibodies on ready-made histological preparations of the surgical material. The expression level of these markers was estimated as a percentage from 0 to 100%. The immediate and long-term results of the most commonly used drug treatment regimens (doxorubicin-containing regimens and gemcitabine + docetaxel combinations) were analyzed depending on the level of phospho-mTOR expression in the tumor. Results. The expression of mTOR in the tumor was detected in 4 patients with an expression level from 1 to 2%, and the expression of phospho-mTOR was detected in 20 patients with an expression level from 1 to 70%. Median OS in the group without phospho-mTOR expression was 135 months, in the group with expression 104 months, p=0.732. When using doxorubicin-containing regimens in the group with phospho-mTOR expression, 12% of patients had a partial response (PR), median PFS was 26.7 months, in the group without expression there was no PR, median PFS was 8.7 months, p=0.67. When using a combination of gemcitabine + docetaxel, in the group with phospho-mTOR expression, 24% of patients had PR, median PFS was 11.1 months, in the group without expression, 14% of patients had PR, median PFS was 12.4 months, p=0.372. Conclusion. Phospho-mTOR expression was detected in 2/3 of patients with high-grade uterine LMS. There was no effect of the expression of this marker on the OS of all included patients and on PFS in patients who received chemotherapy according to the gemcitabine + docetaxel regime. There was a tendency to an increase in PFS in the group with phospho-mTOR expression in patients who received doxorubicin-containing chemotherapy regimens.

Kidney transplant recipients are at high risk of developing severe COVID-19 due to the coexistence of several transplant-related comorbidities (e.g., cardiovascular disease, diabetes) and chronic immunosuppression. As a consequence, a large part of SARS-CoV-2 infected patients have been managed with a reduction of immunosuppression. The mTOR-I, together with antimetabolites, have been often discontinued in order to minimize the risk of pulmonary toxicity and to antagonize pharmacological interaction with antiviral/anti-inflammatory drugs. However, at our opinion, this therapeutic strategy, although justified in kidney transplant recipients with severe COVID-19, should be carefully evaluated in asymptomatic/paucisymptomatic patients in order to avoid the onset of acute allograft rejections, to potentially exploit the mTOR-I antiviral properties, to reduce proliferation of conventional T lymphocytes (which could mitigate the cytokine storm) and to preserve Treg growth/activity which could reduce the risk of progression to severe disease. In this review, we discuss the current literature regarding the therapeutic potential of mTOR-Is in kidney transplant recipients with COVID-19 with a focus on pulmonary fibrosis. [ABSTRACT FROM AUTHOR]

Kidney transplant recipients are at high risk of developing severe COVID-19 due to the coexistence of several transplant-related comorbidities (e.g., cardiovascular disease, diabetes) and chronic immunosuppression. As a consequence, a large part of SARS-CoV-2 infected patients have been managed with a reduction of immunosuppression. The mTOR-I, together with antimetabolites, have been often discontinued in order to minimize the risk of pulmonary toxicity and to antagonize pharmacological interaction with antiviral/anti-inflammatory drugs. However, at our opinion, this therapeutic strategy, although justified in kidney transplant recipients with severe COVID-19, should be carefully evaluated in asymptomatic/paucisymptomatic patients in order to avoid the onset of acute allograft rejections, to potentially exploit the mTOR-I antiviral properties, to reduce proliferation of conventional T lymphocytes (which could mitigate the cytokine storm) and to preserve Treg growth/activity which could reduce the risk of progression to severe disease. In this review, we discuss the current literature regarding the therapeutic potential of mTOR-Is in kidney transplant recipients with COVID-19 with a focus on pulmonary fibrosis.

Desmoplastic small round cell tumor (DSRCT) is a devastating disease which most commonly affects adolescents, with a male predominance. Despite the best multimodality treatment efforts, most patients will ultimately not survive more than 3–5 years after diagnosis. Some research trials in soft-tissue sarcoma and Ewing sarcoma include DSRCT patients but few studies have been tailored to the specific clinical needs and underlying cytogenetic abnormalities characterizing this disease such as the typical EWSR1-WT1 gene fusion. Downstream activation of EWSR1-WT1 gene fusion includes signaling pathways of platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and insulin growth factor (IGF)-1. Other biological pathways that are activated and expressed in DSRCT cells include endothelial growth factor receptor (EGFR), androgen receptor pathway, c-KIT, MET, and transforming growth factor (TGF) beta. Investigation of somatic mutations, copy number alterations (CNA), and chromosomes in DSRCT samples suggests that deregulation of mesenchymal-epithelial reverse transition (MErT)/epithelial-mesenchymal transition (EMT) and DNA damage repair (DDR) may be important in DSRCT. This mini review looks at known druggable targets in DSRCT and existing clinical evidence for targeted treatments, particularly multityrosine kinase inhibitors such as pazopanib, imatinib, and sorafenib alone or in combination with other agents such as mTOR (mammalian target of rapamycin) inhibitors. The aim is to increase shared knowledge about current available treatments and identify gaps in research to further efforts toward clinical development of targeted agents.

Over the last decades, our understanding of adaptive immune responses to solid organ transplantation increased considerably and allowed development of immunosuppressive drugs targeting key alloreactive T cells mechanism. As a result, rates of acute rejection dropped and short-term graft survival improved significantly. However, long-term outcomes are still disappointing. Recently, increasing evidence supports that innate immune responses plays roles in allograft rejection and represents a valuable target to further improve long-term allograft survival. Innate immune cells are activated by molecules with stereotypical motifs produced during injury (i.e., damage-associated molecular patterns, DAMPS) or infection (i.e., pathogen-associated molecular patterns, PAMPs). Activated innate immune cells can exert direct pro- and anti-inflammatory effects, while also priming adaptive immune responses. These cells are activated after transplantation by multiple stimuli, including ischemia-reperfusion injury, rejection, and infections. Data from animal models of graft rejection, show that inhibition of innate immunity promotes development of tolerance. Therefore, understanding mechanisms of innate immunity is important to improve graft outcomes. This review discusses effects of currently used immunosuppressive agents on innate immune responses in kidney transplantation.

Desmoplastic small round cell tumor (DSRCT) is a devastating disease which most commonly affects adolescents, with a male predominance. Despite the best multimodality treatment efforts, most patients will ultimately not survive more than 3–5 years after diagnosis. Some research trials in soft-tissue sarcoma and Ewing sarcoma include DSRCT patients but few studies have been tailored to the specific clinical needs and underlying cytogenetic abnormalities characterizing this disease such as the typical EWSR1-WT1 gene fusion. Downstream activation of EWSR1-WT1 gene fusion includes signaling pathways of platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and insulin growth factor (IGF)-1. Other biological pathways that are activated and expressed in DSRCT cells include endothelial growth factor receptor (EGFR), androgen receptor pathway, c-KIT, MET, and transforming growth factor (TGF) beta. Investigation of somatic mutations, copy number alterations (CNA), and chromosomes in DSRCT samples suggests that deregulation of mesenchymal-epithelial reverse transition (MErT)/epithelial-mesenchymal transition (EMT) and DNA damage repair (DDR) may be important in DSRCT. This mini review looks at known druggable targets in DSRCT and existing clinical evidence for targeted treatments, particularly multityrosine kinase inhibitors such as pazopanib, imatinib, and sorafenib alone or in combination with other agents such as mTOR (mammalian target of rapamycin) inhibitors. The aim is to increase shared knowledge about current available treatments and identify gaps in research to further efforts toward clinical development of targeted agents. [ABSTRACT FROM AUTHOR]

Over the last decades, our understanding of adaptive immune responses to solid organ transplantation increased considerably and allowed development of immunosuppressive drugs targeting key alloreactive T cells mechanism. As a result, rates of acute rejection dropped and short-term graft survival improved significantly. However, long-term outcomes are still disappointing. Recently, increasing evidence supports that innate immune responses plays roles in allograft rejection and represents a valuable target to further improve long-term allograft survival. Innate immune cells are activated by molecules with stereotypical motifs produced during injury (i.e., damage-associated molecular patterns, DAMPS) or infection (i.e., pathogen-associated molecular patterns, PAMPs). Activated innate immune cells can exert direct pro- and anti-inflammatory effects, while also priming adaptive immune responses. These cells are activated after transplantation by multiple stimuli, including ischemia-reperfusion injury, rejection, and infections. Data from animal models of graft rejection, show that inhibition of innate immunity promotes development of tolerance. Therefore, understanding mechanisms of innate immunity is important to improve graft outcomes. This review discusses effects of currently used immunosuppressive agents on innate immune responses in kidney transplantation. [ABSTRACT FROM AUTHOR]

Immunosuppressive therapy after kidney transplantation is based on calcineurin inhibitors (CNI). In most cases CNI therapy is combined with mycophenolate and steroids. In spite of good short-term results this therapy is associated with long-term toxicities, graft loss and patient death. Therefore, alternative immunosuppressive strategies are needed that combine excellent efficacy with low incidences of long-term adverse outcomes. This review focuses on the strategies based on mTOR- inhibitors in combination with minimized exposure to CNI. [ABSTRACT FROM AUTHOR]

Abstract: Kidney transplantation has become the treatment of choice in end-stage chronic renal failure since it significantly improves both the quality of life and the life duration of affected patients, when compared with dialysis. Some of these better results that were observed over the last thirty years are obviously due to significant improvements in the quality of immunosuppression. In the first part of this chapter, the allo-immune response is schematically described regarding the various signals. Then, the mechanisms of action of the available or future immunosuppressive therapies are described in the same order as the allo-immune response. In the third part, the various combinations of immunosuppressive regimens are presented from a historical perspective, outlining not only the positive aspects of each class of drugs but also their side effects and consequences on the practical use of immunosuppression over time. Finally, a brief review of current and future perspectives regarding the improvement of both efficacy and tolerability of immunosuppression in kidney transplantation is presented. [Copyright &y& Elsevier]

• mTORi are increasingly used after lung transplantation. • Main reason to start mTORi was renal insufficiency (67%). • mTORi was stopped due to side effects or drug toxicity in 52% of LTR. • Main reasons for discontinuation were infection (19%) and edema (14%). Mammalian target of rapamycin inhibitors (mTORi) are increasingly used after lung transplantation as part of a calcineurin inhibitor sparing regimen, aiming to preserve renal function. The aim of our study was to determine whether immunosuppressive therapy using mTORi in lung transplant recipients (LTR) is feasible in practice, or limited by intolerance and adverse events. Data were retrospectively assessed for all LTR transplanted between July 1991 and January 2020. Patients ever receiving mTORi (monotherapy or in combination with calcineurin inhibitor) as treatment of physicians' choice were included. 149/1184 (13%) of the LTR ever received mTORi. Main reasons to start were renal insufficiency (67%) and malignancy (21%). In 52% of the patients, mTORi was stopped due to side effects or drug toxicity after a median time of 159 days. Apart from death, main reasons for discontinuation were infection (19%) and edema (14%). Early discontinuation (<90 days) was mainly due to edema or gastrointestinal intolerance. As mTORi was stopped due to adverse events or drug intolerance in 52% of LTR, cautious consideration of advantages and disadvantages when starting mTORi is recommended. [ABSTRACT FROM AUTHOR]

Non-clear cell (ncc) renal cell carcinoma (RCC) accounts for ≈25% of all patients with metastatic RCC. It is refractory to standard immuno(chemo)therapy and, to date, no specific trials have been reported to evaluate the efficacy of novel targeted drugs in the different subtypes of metastatic nccRCC. We review all available data from subgroup analyses of the global sorafenib and sunitinib expanded access programmes, current phase-III trials, and smaller multi- and single-centre studies focusing on the activity of targeted agents in these specific and rare RCC subtypes. Both sorafenib and sunitinib have significant activity in metastatic nccRCC, but the efficacy of each agent seems to vary between different nccRCC forms. Preliminary clinical data for temsirolimus appear to be promising but more extensive and long-term data are awaited. With the advent of novel therapeutic options, specific controlled multicentre trials are urgently needed to define their exact value and efficacy for treating the historically resistant nccRCC forms. The medium-term aim should be to tailor the most advantageous therapy for each patient with respect to his/her individual RCC subtype and physical condition. [ABSTRACT FROM AUTHOR]