Pembrolizumab-related Immune Thrombocytopenia in a Patient with Lung Adenocarcinoma Treated by Radiotherapy: Potential Immune-related Adverse Event Elicited by Radiation Therapy

The effect of radiotherapy during immunotherapy on immune-related adverse events (irAEs) is not fully understood. We herein report a 74-year-old woman diagnosed with lung adenocarcinoma with programmed death ligand 1 expression ≥50% and treated with pembrolizumab. She developed fatal immune thrombocytopenia associated with pembrolizumab immediately following radiotherapy. A flow cytometry analysis of peripheral blood detected an increased expression of programmed death-1 (PD-1) and Ki-67 in CD4^＋ and CD8^＋ T cells after radiotherapy, compared with pre-irradiation measurements. This case suggests that radiotherapy may evoke irAEs during treatment with anti-PD-1 antibodies, which physicians should consider when using radiotherapy in patients treated with these drugs.     

Absolute lymphocyte count and C-reactive protein-albumin ratio can predict prognosis and adverse events in patients with recurrent esophageal cancer treated with nivolumab therapy

Predicting the prognosis and adverse events (AEs) of nivolumab therapy for recurrent esophageal cancer is very important. The present study investigated whether a simple blood biochemical examination could be used to predict prognosis and AEs following nivolumab treatment for relapse of esophageal cancer. A total of 41 patients who received nivolumab treatment for recurrent esophageal cancer after esophagectomy were analyzed. The absolute lymphocyte count (ALC), neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR) and C-reactive protein-albumin ratio (CAR) were assessed at the time of nivolumab induction as indices that can be calculated by blood biochemical examinations alone. Median values were 1,015 for ALC, 3.401 for NLR, 242.6 for PLR, 0.458 for MLR and 0.119 for CAR, and patients were divided into two groups according to values. A high ALC, low NLR, low PLR, low MLR and low CAR were associated with a better response to nivolumab. In addition, patients with the aforementioned indices, with the exception of low PLR, or better response were more likely to develop AEs in univariate analysis. In multivariate analysis, a high ALC [odds ratio (OR): 4.857, P=0.043] and low CAR (OR: 9.099, P=0.004) were identified as independent risk factors for AEs. Survival analysis revealed that overall survival and progression-free survival (PFS) rates after nivolumab treatment differed significantly between the high and low groups of ALC, NLR, PLR, MLR and CAR. The multivariate analysis identified a low ALC [hazard ratio (HR): 3.710, P=0.003] and high CAR (HR: 2.953, P=0.007) as independent poor prognostic factors of PFS. In conclusion, ALC and CAR have potential as biomarkers for outcomes of recurrent esophageal cancer following nivolumab treatment.     

AU-1 from Agavaceae plants causes transient increase in p21/Cip1 expression in renal adenocarcinoma ACHN cells in an miR-34-dependent manner

Here, we show that AU-1, spirostanol saponin isolated from Agavaceae plants, causes a transient increase in cyclin-dependent kinase inhibitor (CDKI) p21/Cip1 through the upregulation of miRNAs, miR-34 and miR-21. AU-1 stimulated p21/Cip1 expression without exerting cytotoxicity against different types of carcinoma cell lines. In renal adenocarcinoma ACHN cells, AU-1 transiently elevated the expression level of p21/Cip1 protein without marked increases in p21/Cip1 mRNA levels. Rapid and transient increases in miR-34 and miR-21, both of which are known to upregulate p21/Cip1, were observed in AU-1-treated cells. Inhibitor for miR-34 and for miR-21 significantly blocked the AU-1-caused increase in p21/Cip1, indicating that elevation of p21/Cip1 protein by AU-1 is dependent on these microRNAs. We further clarified that NAD-dependent deacetylase SIRT1, a direct target of miR-34, is decreased by the treatment with AU-1. Furthermore, we found that SIRT1-knockdown increases p21/Cip1 protein levels in an miR-21-dependent manner. On the other hand, ectopic expression of p21/Cip1 resulted in the lowered expression of miR-34 and miR-21, suggesting that reciprocal regulation exists between p21/Cip1 and these miRNAs. We propose that the following feedback network composed of miR-34/SIRT1/miR-21/p21 is triggered by the treatment with AU-1: in cells treated with AU-1, transient elevation of miR-34 leads to the downregulation of SIRT1, thereby miR-21 is freed from SIRT1-dependent suppression. Then, elevated miR-21 upregulates p21/Cip1 protein, followed by the suppression of miR-34 expression.     

Identification of a Novel Titin Variant Underlying Myocardial Involvement in Neurofibromatosis Type 1

Because of the rare co-occurrence, it remains a question whether cardiomyopathy is a true association of neurofibromatosis type 1. A boy with café-au-lait spots manifested restrictive cardiomyopathy. Whole exome sequencing confirmed the genetic diagnosis of neurofibromatosis and further identified a novel titin (TTN) missense variant. The significance of the variant is supported by its de novo origin, in silico predictions, and evolutionary conservation. Modern genetics raises an intriguing explanation for the unexpected phenotype and adds to the evolving role of TTN variants in cardiomyopathy.     

Oncolytic Virus Therapy with HSV-1 for Hematological Malignancies

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Changes in wall shear stress magnitude after aneurysm rupture

Computational fluid dynamics (CFD) studies on cerebral aneurysms have attempted to identify surrogate hemodynamic parameters to predict rupture risk. We present a case of bilateral mirror image aneurysms, one of which ruptured soon after imaging. Wall shear stress values of the ruptured aneurysm changed by 20–30 % after rupture because of change in the aneurysm shape. Findings from our case suggest that CFD studies comparing unruptured and ruptured aneurysms may not yield valid estimation on aneurysm rupture risk because of changes in aneurysm shape after rupture. Changes in aneurysm shape after rupture should be considered in CFD research.