A 55-kDa endonuclease of mammalian mitochondria: comparison of its subcellular localization and endonucleolytic properties with those of endonuclease G

A novel endonuclease of 55-kDa was found in rat liver mitochondria by a zymographic assay, in addition to the 29 kDa enzyme that is well-known as endonuclease G (Endo G). Subcellular localization of these enzymes in rat liver cells was examined by biochemical fractionation. Endo G was located in both nuclei and mitochondria as has been previously reported, while the 55-kDa enzyme was only detected in the mitochondrial fraction. The levels of the endonucleases in the mitochondria varied greatly among the rat organs, and the activity in the heart was about 30 times higher than that in the liver. The 55-kDa enzyme and Endo G were extracted from bovine heart mitochondria with 0.4 M NaCl. During purification the 55-kDa enzyme and Endo G were copurified because of their similar chromatographic behavior, so they were separated by gel filtration or electrophoresis in the presence of SDS and the proteins were then renatured. The nucleolytic properties of the 55-kDa enzyme resembled those of Endo G and other known mitochondrial nucleases. The enzyme degraded single-stranded DNA more rapidly than duplex DNA at a weak alkaline pH, requiring Mg2+ or Mn2+ but not Ca2+ or Zn2+. Nicks generated by the enzyme had 5&#8242;-P and 3&#8242;-OH ends. The 55-kDa enzyme, like Endo G, displayed an unusually strong preference to nick within a (dG)n · (dC)n tract.</p

Japanese Lung Cancer Society Guidelines for Stage IV NSCLC With EGFR Mutations

Patients with NSCLC in East Asia, including Japan, frequently contain EGFR mutations. In 2018, we published the latest full clinical practice guidelines on the basis of those provided by the Japanese Lung Cancer Society Guidelines Committee. The purpose of this study was to update those recommendations, especially for the treatment of metastatic or recurrent EGFR-mutated NSCLC. We conducted a literature search of systematic reviews of randomized controlled and nonrandomized trials published between 2018 and 2019 that multiple physicians had reviewed independently. On the basis of those studies and the advice from the Japanese Society of Lung Cancer Expert Panel, we developed updated guidelines according to the Grading of Recommendations, Assessment, Development, and Evaluation system. We also evaluated the benefits of overall and progression-free survival, end points, toxicities, and patients’ reported outcomes. For patients with NSCLC harboring EGFR-activating mutations, the use of EGFR tyrosine kinase inhibitors (EGFR TKIs), especially osimertinib, had the best recommendation as to first-line treatment. We also recommended the combination of EGFR TKI with other agents (platinum-based chemotherapy or antiangiogenic agents); however, it can lead to toxicity. In the presence of EGFR uncommon mutations, except for an exon 20 insertion, we also recommended the EGFR TKI treatment. However, we could not provide recommendations for the treatment of EGFR mutations with immune checkpoint inhibitors, including monotherapy, and its combination with cytotoxic chemotherapy, because of the limited evidence present in the literature. The 2020 Japanese Lung Cancer Society Guidelines can help community-based physicians to determine the most appropriate treatments and adequately provide medical care to their patients

Low-Dose Intravenous Alteplase in Wake-Up Stroke

Background and Purpose—We assessed whether lower-dose alteplase at 0.6 mg/kg is efficacious and safe for acute fluid-attenuated inversion recovery-negative stroke with unknown time of onset. Methods—This was an investigator-initiated, multicenter, randomized, open-label, blinded-end point trial. Patients met the standard indication criteria for intravenous thrombolysis other than a time last-known-well >4.5 hours (eg, wake-up stroke). Patients were randomly assigned (1:1) to receive alteplase at 0.6 mg/kg or standard medical treatment if magnetic resonance imaging showed acute ischemic lesion on diffusion-weighted imaging and no marked corresponding hyperintensity on fluid-attenuated inversion recovery. The primary outcome was a favorable outcome (90-day modified Rankin Scale score of 0–1). Results—Following the early stop and positive results of the WAKE-UP trial (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke), this trial was prematurely terminated with 131 of the anticipated 300 patients (55 women; mean age, 74.4±12.2 years). Favorable outcome was comparable between the alteplase group (32/68, 47.1%) and the control group (28/58, 48.3%; relative risk [RR], 0.97 [95% CI, 0.68–1.41]; P=0.892). Symptomatic intracranial hemorrhage within 22 to 36 hours occurred in 1/71 and 0/60 (RR, infinity [95% CI, 0.06 to infinity]; P>0.999), respectively. Death at 90 days occurred in 2/71 and 2/60 (RR, 0.85 [95% CI, 0.06–12.58]; P>0.999), respectively. Conclusions—No difference in favorable outcome was seen between alteplase and control groups among patients with ischemic stroke with unknown time of onset. The safety of alteplase at 0.6 mg/kg was comparable to that of standard treatment. Early study termination precludes any definitive conclusions

SH3YL1 regulates dorsal ruffle formation by a novel phosphoinositide-binding domain

The newly identified SYLF lipid-binding domain of SH3YL1 mediates phosphoinositide binding during dorsal membrane morphogenesis

Long-term outcomes of proton beam therapy in patients with previously untreated hepatocellular carcinoma

Long-term efficacy of proton beam therapy (PBT) remains unclear for patients with previously untreated hepatocellular carcinoma (HCC). We aimed to study the long-term outcomes of PBT according to Barcelona Clinic Liver Cancer (BCLC) staging classifications in patients with previously untreated HCC. The major eligibility criteria of this observational study were an Eastern Cooperative Oncology Group performance status (PS) 0–2, Child–Pugh grade A or B, previously untreated HCC covered within an irradiation field, and no massive ascites. A total of 66.0–77.0 GyE was administered in 10–35 fractions. Local tumor control (LTC), defined as no progression in the irradiated field, progression-free survival (PFS), and overall survival (OS) were assessed according to BCLC staging. From 2002 to 2009 at our institution, 129 patients were eligible. The 5-year LTC, PFS, and OS rates were 94%, 28%, and 69% for patients with 0/A stage disease (n = 9/21), 87%, 23%, and 66% for patients with B stage disease (n = 34), and 75%, 9%, and 25% for patients with C stage disease (n = 65), respectively. The 5-year LTC and OS rates of 15 patients with tumor thrombi in major vessels were 90% and 34%, respectively. Multivariate analyses revealed that PS (0 versus 1–2) was a significant prognostic factor for OS. No grade 3 or higher adverse effects were observed. PBT showed favorable long-term efficacies with mild adverse effects in BCLC stage 0 to C, and can be an alternative treatment for localized HCC especially when accompanied with tumor thrombi. This study was registered with UMIN Clinical Trials Registry (UMIN000025342)