Risk factors for relapse of immune-related pneumonitis after 6-week oral prednisolone therapy: a follow-up analysis of a phase II study.

BACKGROUND: Immune-related pneumonitis (irP) is one of the most important immune-related adverse events caused by immune checkpoint inhibitors (ICIs). After corticosteroid therapy irP frequently relapses, which can interfere with cancer therapy. However, risk factors for irP relapse are unknown. METHODS: This study was a follow-up analysis of a phase II study that evaluated 56 patients with grade ≥ 2 irP treated with oral prednisolone, 1 mg/kg/day, tapered over 6 weeks. Clinical factors including patient characteristics, blood test findings, and response to prednisolone therapy were assessed to identify risk factors for irP relapse using the Fine-Gray test. RESULTS: Among 56 patients with irP, 22 (39.3%) experienced irP relapse after 6 weeks of prednisolone therapy during the follow-up observation period. Radiographic organising pneumonia (OP) pattern and duration to irP onset ≥ 100 days from ICI initiation were determined to be significant risk factors for irP relapse in a multivariate Fine-Gray test (hazard ratio [HR] = 3.17, 95% CI 1.37-7.32, p = 0.007, and HR = 2.61, 95% CI 1.01-6.74, p = 0.048, respectively). Other patient characteristics, blood test findings, irP severity, and response to prednisolone therapy were not associated with irP relapse. CONCLUSIONS: In irP patients treated with 6-week prednisolone tapering therapy, OP pattern and duration to irP onset ≥ 100 days were associated with relapse risk. Assessment of the risk factors for irP relapse will be helpful for irP management.

Particle Size Measurement and Detection of Bound Proteins of Non-Porous/Mesoporous Silica Microspheres by Single-Particle Inductively Coupled Plasma Mass Spectrometry.

Single-particle inductively coupled plasma mass spectrometry (spICP-MS) has been used for particle size measurement of diverse types of individual nanoparticles and micrometer-sized carbon-based particles such as microplastics. However, its applicability to the measurement of micrometer-sized non-carbon-based particles such as silica (SiO2) particles is unclear. In this study, the applicability of spICP-MS to particle size measurement of non-porous/mesoporous SiO2 microspheres with a nominal diameter of 5.0 µm or smaller was investigated. Particle sizes of these microspheres were measured using both spICP-MS based on a conventional calibration approach using an ion standard solution and scanning electron microscopy as a reference technique, and the results were compared. The particle size distributions obtained using both techniques were in agreement within analytical uncertainty. The applicability of this technique to the detection of metal-containing protein-binding mesoporous SiO2 microspheres was also investigated. Bound iron (Fe)-containing proteins (i.e., lactoferrin and transferrin) of mesoporous SiO2 microspheres were detected using Fe as a presence marker for the proteins. Thus, spICP-MS is applicable to the particle size measurement of large-sized and non-porous/mesoporous SiO2 microspheres. It has considerable potential for element-based detection and qualification of bound proteins of mesoporous SiO2 microspheres in a variety of applications.

Cytokine profiling identifies circulating IL-6 and IL-15 as prognostic stratifiers in patients with non-small cell lung cancer receiving anti-PD-1/PD-L1 blockade therapy.

Whether circulating levels of specific cytokines at baseline link with treatment efficacy of immune checkpoint blockade (ICB) therapy in patients with non-small cell lung cancer remains unknown. In this study, serum samples were collected in two independent, prospective, multicenter cohorts before the initiation of ICB. Twenty cytokines were quantified, and cutoff values were determined by receiver operating characteristic analyses to predict non-durable benefit. The associations of each dichotomized cytokine status with survival outcomes were assessed. In the discovery cohort (atezolizumab cohort; N = 81), there were significant differences in progression-free survival (PFS) in accordance with the levels of IL-6 (log-rank test, P = 0.0014), IL-15 (P = 0.00011), MCP-1 (P = 0.013), MIP-1ß (P = 0.0035), and PDGF-AB/BB (P = 0.016). Of these, levels of IL-6 and IL-15 were also significantly prognostic in the validation cohort (nivolumab cohort, N = 139) for PFS (log-rank test, P = 0.011 for IL-6 and P = 0.00065 for IL-15) and overall survival (OS; P = 3.3E-6 for IL-6 and P = 0.0022 for IL-15). In the merged cohort, IL-6high and IL-15high were identified as independent unfavorable prognostic factors for PFS and OS. The combined IL-6 and IL-15 status stratified patient survival outcomes into three distinct groups for both PFS and OS. In conclusion, combined assessment of circulating IL-6 and IL-15 levels at baseline provides valuable information to stratify the clinical outcome of patients with non-small cell lung cancer treated with ICB. Further studies are required to decipher the mechanistic basis of this finding.

An autopsy case of disseminated Cunninghamella bertholletiae infection in an immunocompetent patient: a case report.

BACKGROUND: Recently, deaths due to mucormycosis in immunocompromised hosts have increased; however, the clinical and pathological features of mucormycosis are not fully understood, especially in view of the associated high mortality and rare incidence in immunocompetent patients. CASE PRESENTATION: We have described a rare autopsy case of a 67-year-old Japanese man with chronic obstructive pulmonary disease who contracted mucormycosis. He had not been on any immunosuppressants, and his immune functions were intact. Since 3 days prior to admission to our hospital, he had experienced progressive dyspnea, productive cough, and fever. Chest computed tomography revealed pleural effusion in the left lower hemithorax and consolidation in the right lung field. Although he was administered with tazobactam-piperacillin hydrate (13.5 g/day), renal dysfunction occurred on the ninth disease day. Therefore, it was switched to cefepime (2 g/day). However, his general condition and lung-field abnormality worsened gradually. Cytological analysis of the sputum sample at admission mainly revealed sporangiophores and unicellular sporangioles, while repeated sputum culture yielded Cunninghamella species. Therefore, he was diagnosed with pulmonary mucormycosis. Liposomal amphotericin B (5 mg/kg/day) was initiated on the 28th disease day. However, chest radiography and electrocardiography detected cardiomegaly and atrial fibrillation, respectively, and he died on the 37th disease day. A postmortem examination revealed clusters of fungal hyphae within the arteries of the right pulmonary cavity wall, the subpericardial artery, intramyocardial capillary blood vessels, and the esophageal subserosa vein. Direct sequencing revealed that all fungal culture samples were positive for Cunninghamella bertholletiae. CONCLUSIONS: Cunninghamella bertholletiae could rapidly progress from colonizing the bronchi to infecting the surrounding organs via vascular invasion even in immunocompetent patients.

Increased serum cholesterol and long-chain fatty acid levels are associated with the efficacy of nivolumab in patients with non-small cell lung cancer.

BACKGROUND: Lipids have immunomodulatory functions and the potential to affect cancer immunity. METHODS: The associations of pretreatment serum cholesterol and long-chain fatty acids with the objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) were evaluated in 148 patients with non-small cell lung cancer who received nivolumab. RESULTS: When each lipid was separately evaluated, increased low-density lipoprotein (LDL)-cholesterol (P < 0.001), high-density lipoprotein (HDL)-cholesterol (P = 0.014), total cholesterol (P = 0.007), lauric acid (P = 0.015), myristic acid (P = 0.022), myristoleic acid (P = 0.035), stearic acid (P = 0.028), linoleic acid (P = 0.005), arachidic acid (P = 0.027), eicosadienoic acid (P = 0.017), dihomo-γ-linolenic acid (P = 0.036), and behenic acid levels (P = 0.032) were associated with longer PFS independent of programmed death ligand 1 (PD-L1) expression. Meanwhile, increased LDL-cholesterol (P < 0.001), HDL-cholesterol (P = 0.009), total cholesterol (P = 0.036), linoleic acid (P = 0.014), and lignoceric acid levels (P = 0.028) were associated with longer OS independent of PD-L1 expression. When multiple lipids were evaluated simultaneously, LDL-cholesterol (P = 0.003), HDL-cholesterol (P = 0.036), and lauric acid (P = 0.036) were independently predictive of PFS, and LDL-cholesterol (P = 0.008) and HDL-cholesterol (P = 0.031) were predictive of OS. ORR was not associated with any serum lipid. CONCLUSIONS: Based on the association of prolonged survival in patients with increased serum cholesterol and long-chain fatty acid levels, serum lipid levels may be useful for predicting the efficacy of immune checkpoint inhibitor therapy.

The Geriatric Nutritional Risk Index and Prognostic Nutritional Index Predict the Overall Survival of Advanced Non-Small Cell Lung Cancer Patients.

We aimed to assess the prognostic and predictive significance of pretreatment Geriatric Nutritional Risk Index (GNRI) and Prognostic Nutritional Index (PNI) measurements on advanced non-small cell lung cancer (NSCLC) patients treated with first-line therapy. Patients with advanced NSCLC treated between February 2014 and August 2020 were retrospectively analyzed. The optimal cutoff points for GNRI and PNI were measured with receiver operating characteristic (ROC) curve analysis according to overall survival (OS). The predictive factors for progression-free survival (PFS) and OS were evaluated with univariate and multivariate analyses via the Cox hazards regression. A total of 160 patients were included in the study. Significant differences between the low and high-GNRI or PNI groups were found regarding ECOG-PS. The low-GNRI and low-PNI groups had significantly shorter PFS and OS than the high-GNRI and high-PNI groups. A multivariate analysis using a Cox regression model revealed that the high-GNRI group was an independent prognostic factor of OS and PFS, and the PNI group was an independent prognostic factor of OS. Pretreatment GNRI and PNI may therefore be a potential effective predictor of the survival of advanced NSCLC patients undergoing first-line treatment.

Erlotinib and bevacizumab in elderly patients ≥75 years old with non-small cell lung cancer harboring epidermal growth factor receptor mutations.

The efficacy and safety of combination therapy with erlotinib and bevacizumab in elderly patients with non-small-cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) gene mutations are unknown. Elderly patients aged ≥75 years old with advanced or recurrent NSCLC and EGFR mutations (exon 19 deletion or L858R mutation in exon 21) received erlotinib (150 mg, daily) and bevacizumab (15 mg/kg on day 1 of a 21-day cycle) until disease progression or the occurrence of unacceptable toxicities. The primary endpoint was progression-free survival from enrollment. Twenty-five patients were enrolled in this study, and the median age was 80 years. Fifteen (60.0%) and 10 patients (40.0%) had exon 21 L858R mutations and exon 19 deletions, respectively. The median progression-free survival from enrollment was 12.6 months [95% confidence interval (CI): 8.0-33.7 months]. The objective response rate was 88.0% [95% CI: 74.0%-99.0%], and the disease control rate was 100% [95% CI: 88.7%-100%]. Grade 3 or higher adverse events occurred in 12 patients (48.0%), and rash and nausea were the most common. Grade 3 or higher bevacizumab-related toxicities occurred in 4 (16.0%) patients, including proteinuria (n = 2), gastrointestinal perforation (n = 1) and pneumothorax (n = 1). A dose reduction of erlotinib and cessation of bevacizumab was required in 16 (64.0%) and 18 patients (72.0%), respectively. Erlotinib and bevacizumab combination therapy showed a minimal survival benefit with frequent dose reductions and/or treatment discontinuations in elderly patients with EGFR-positive NSCLC.

Programmed cell death-1 blockade in kidney carcinoma may induce eosinophilic granulomatosis with polyangiitis: a case report.

BACKGROUND: Immune checkpoint inhibitors have potential applications in treating various cancers but are associated with immune-related adverse events, such as inflammation, in a wide range of organs; however, allergic inflammation caused by these agents has not been extensively studied. CASE PRESENTATION: A 65-year-old man was diagnosed with a kidney neuroendocrine carcinoma. Three months after kidney resection surgery, the tumor cells had metastasized to his liver and lymph nodes. Subsequently, the patient started chemotherapy; however, regardless of treatment, the tumor grew, and the patient experienced a series of adverse effects, such as taste disorder, anorexia, and general fatigue. Finally, he was administered a programmed cell death (PD)-1 inhibitor, nivolumab (biweekly, toal 200 mg/body), which was effective against kidney carcinoma. However, the patient had a bronchial asthma attack at 22 cycles of nivolumab treatment and chest computed tomography (CT) revealed an abnormal bilateral shadow after 37 cycles of nivolumab treatment. Bronchoscopy findings revealed eosinophil infiltration in the lungs along with severe alveolar hemorrhage. Paranasal sinus CT scanning indicated sinusitis and nerve conduction analysis indicated a decrease in his right ulnar nerve conduction velocity. Based on these findings, the patient was diagnosed with eosinophilic granulomatosis with polyangiitis; he was treated with prednisolone, which alleviated his bronchial asthma. To restart nivolumab treatment, the dose of prednisolone was gradually tapered, and the patient was administered a monthly dose of mepolizumab and biweekly dose of nivolumab. To date, there have been no bronchial attacks or CT scan abnormalities upon follow up. CONCLUSIONS: We present a rare case in which a patient with cancer was diagnosed with eosinophilic granulomatosis with polyangiitis following treatment with a PD-1 inhibitor. Blockade of PD-1 and the programmed cell death ligand (PD-L) 1/PD-1 and PD-L2/PD-1 signaling cascade may cause allergic inflammation. Further studies are needed to identify the specific mechanisms underlying allergic inflammation after PD-1 blockade.

Efficacy of immune checkpoint inhibitors in non-small cell lung cancer with uncommon histology: a propensity-score-matched analysis.

BACKGROUND: Clinical efficacy of immune checkpoint inhibitors (ICIs) for non-small cell lung cancer (NSCLC) with uncommon histology (uNSCLC) is unknown. METHODS: Patients with NSCLC treated with ICI monotherapy between January 2014 and December 2018 in 10 Japanese hospitals were retrospectively evaluated. The patients were divided into: (1) NSCLC with common histology (cNSCLC), defined as adenocarcinoma and squamous cell carcinoma; and (2) uNSCLC, defined as incompatibility with morphological and immunohistochemical criteria for adenocarcinoma or squamous cell carcinoma. Propensity score matching was performed to balance the two groups. RESULTS: Among a total of 175 patients included, 44 with uNSCLC (10 pleomorphic carcinomas, 9 large cell neuroendocrine carcinomas, 2 large cell carcinomas, and 23 not otherwise specified) and 44 with matched cNSCLC (32 adenocarcinomas and 12 squamous cell carcinomas) were selected for analyses. Median progression-free survival (PFS) (4.4 months, 95% confidence interval [CI] 1.8-7.7 months) and overall survival (OS) (11.4 months, 95% CI 7.4-27.4 months) in the uNSCLC patients were not significantly different from those in matched cNSCLC patients (5.4 months, 95% CI 3.1-7.6 months, p = 0.761; and 14.1 months, 95% CI 10.6-29.6 months, p = 0.381). In multivariate analysis, Eastern Cooperative Oncology Group performance status (ECOG-PS) of 0-1 and programmed death ligand-1 (PD-L1) expression were predictive for PFS and OS in uNSCLC. CONCLUSIONS: ICIs had similar clinical efficacy for treatment of uNSCLC and cNSCLC. Good ECOG-PS and PD-L1 expression were predictive for efficacy of ICIs in uNSCLC.

Switch maintenance therapy with S-1 after induction therapy with carboplatin and nanoparticle albumin-bound paclitaxel in advanced lung squamous cell carcinoma.

Background Optimal maintenance therapy for lung squamous cell carcinoma (SCC) has not been established. The aim of this study was to evaluate the efficacy and safety of switch maintenance therapy with S-1, an oral fluoropyrimidine, after induction therapy with carboplatin and nanoparticle albumin-bound paclitaxel (nab-paclitaxel) in chemotherapy-naïve patients with advanced SCC. Methods Chemotherapy-naïve patients with advanced SCC received induction therapy with four cycles of carboplatin (at an area under the curve of 6, day 1 of a 28-day cycle) and nab-paclitaxel (100 mg/kg, days 1, 8, and 15). Patients who achieved disease control after induction therapy received maintenance therapy with S-1 (80 mg/m2, days 1-14 of a 21-day cycle) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) from the start of maintenance therapy. Results Seventy-two patients with SCC were enrolled to the study. After four cycles of induction therapy, 35 (48.6%) patients achieved disease control, and 31 (43.1%) of these patients received maintenance therapy. Median PFS from the start of maintenance therapy was 3.0 months (95% confidence interval: 2.1-3.8 months). The most common toxicities of grade 3 or higher during maintenance therapy were nausea (13.3%), neutropenia (10.0%), and diarrhea (6.7%). Conclusions Switch maintenance therapy with S-1 after induction therapy with carboplatin and nab-paclitaxel was associated with moderate efficacy and acceptable safety and may represent a feasible treatment option for patients with advanced SCC.

Enzyme Immobilization in Mesoporous Silica for Enhancement of Thermostability.

Direct enzyme immobilization by encapsulation in the pores of mesoporous silica particles enhances protein thermal and chemical stability. In this study, we investigated the effect of pore size on the thermostability and catalytic activity of Escherichia coli glutaminase YbaS encapsulated under high temperature conditions in two SBA-type mesoporous silicas: SBA5.4 and SBA10.6 with pore diameters of 5.4 and 10.6 nm, respectively. The changes in enzyme conformation under high temperature conditions were assessed using PSA, a benzophenoxazine-based fluorescent dye that is sensitive to denatured aggregated proteins. The results showed that YbaS adsorption to SBA10.6 was higher than that to SBA5.4 and that SBA10.6-encapsulated YbaS was more resistant to heat treatment and maintained higher conformational stability than SBA5.4-encapsulated or free enzyme. Moreover, the heat-treated YbaS-SBA10.6 composite demonstrated high catalytic activity in glutamine hydrolysis. Thus, enzyme encapsulation in suitable silica mesopores can prevent heat-induced denaturation and subsequent aggregation of the enzyme.

Surgical resection for clinical stage I high-grade neuroendocrine carcinoma of the lung.

BACKGROUND: There are few reports about the factor influencing the prognosis of high-grade neuroendocrine carcinoma. In this study, we evaluated surgical outcome of clinical stage I high-grade neuroendocrine carcinoma. METHODS: Patients who underwent curative surgery for high-grade neuroendocrine tumors of the lung in clinical stage I were included in this study. We retrospectively analyzed 27 consecutive patients. The aim of this study was to clarify the clinical course of the disease after surgery and what factors influence the prognosis. RESULTS: Twenty-two patients have small cell carcinoma, and 5 patients have large cell neuroendocrine carcinoma. Patients who could undergo surgery within 60 days after the first visit (p < 0.01) and undergo lobectomy (p < 0.01) and whose pro-gastrin-releasing peptide ≦ 72 pg/ml (p = 0.04) performed good prognosis after surgery. In multivariate analysis, surgery within 60 days and operative procedure were independent factors associated with OS. CONCLUSION: Surgical resection for clinical stage I high-grade neuroendocrine carcinoma of the lung should be performed as early as possible, and better outcome can be obtained with lobectomy than partial resection.

Characterization of V-set and immunoglobulin domain containing 1 exerting a tumor suppressor function in gastric, lung, and esophageal cancer cells.

V-set and immunoglobulin domain containing 1 (VSIG1) is a newly discovered member of the immunoglobulin superfamily of proteins, expressed in normal stomach and testis. In cancers, however, the clinical and biological roles of VSIG1 remain unknown. Here we investigated VSIG1 expression in 11 cancers and assessed the prognostic roles of VSIG1 in patients with gastric cancer (GC) (n = 362) and non-small-cell lung cancer (n = 650). V-set and immunoglobulin domain containing 1 was downregulated in 60.5% of GC specimens, and high VSIG1 expression was identified as an independent favorable prognostic factor for overall survival in GC patients (hazard ratio, 0.58; 95% confidence interval, 0.35-0.96). Among lung adenocarcinomas (n = 428), VSIG1 was significantly and inversely associated with thyroid transcription factor 1 expression and was frequently expressed in the invasive mucinous subtype (17 of 19, 89.5%). In addition, VSIG1 was expressed in a subset of pancreatic, ovarian, and prostate cancers. The variant 2 VSIG1 transcript was the dominant form in these tissues and cancer cells. Introduction of VSIG1 significantly reduced the proliferative ability of MKN1 and MKN28 GC cells and H1299 lung cancer cells and downregulated cell migration of these cells, as well as of KYSE150, an esophageal cancer cell line. Cell invasion of MKN1, MKN28, and KYSE150 cells was also reduced by VSIG1 introduction. In vitro characterization revealed that VSIG1 forms homodimers through homophilic cis-interactions but not through homophilic trans-interactions. These results suggest that VSIG1 possesses tumor suppressive functions that are translated into favorable prognosis of VSIG1-expressing GC patients.

[Endobronchial Hamartoma Requiring Lobectomy;Report of a Case].

We present a rare case of endobronchial hamartoma that required right middle and lower lobectomy. A 59-year-old man presented with cough and sputum lasting for 9 months. Chest X-ray revealed obstructive pneumonia of the right inferior lobe. Chest computed tomography demonstrated an intrabronchial mass lesion, size 12×12 mm, occluding the entrance of the right lower lobe bronchus associated with obstructive pneumonia of the right inferior lobe. Because transbronchial biopsy could not confirm the diagnosis, we performed a right middle and lower lobectomy to diagnose and treat obstructive pneumonia. Histopathological diagnosis of the tumor was hamartoma. Hamartoma, the most common benign lung tumor, is classified into the following 2 types:pulmonary parenchyma and endobronchial, the latter is relatively rare. Although hamartomas have benign characteristics, cases of endobronchial hamartomas associated with obstructive pneumonia may require lobectomy.

Direct single-molecule observations of local denaturation of a DNA double helix under a negative supercoil state.

Effects of a negative supercoil on the local denaturation of the DNA double helix were studied at the single-molecule level. The local denaturation in λDNA and λDNA containing the SV40 origin of DNA replication (SV40ori-λDNA) was directly observed by staining single-stranded DNA regions with a fusion protein comprising the ssDNA binding domain of a 70-kDa subunit of replication protein A and an enhanced yellow fluorescent protein (RPA-YFP) followed by staining the double-stranded DNA regions with YOYO-1. The local denaturation of λDNA and SV40ori-λDNA under a negative supercoil state was observed as single bright spots at the single-stranded regions. When negative supercoil densities were gradually increased to 0, -0.045, and -0.095 for λDNA and 0, -0.047, and -0.1 for SV40ori-λDNA, single bright spots at the single-stranded regions were frequently induced under higher negative supercoil densities of -0.095 for λDNA and -0.1 for SV40ori-λDNA. However, single bright spots of the single-stranded regions were rarely observed below a negative supercoil density of -0.045 and -0.047 for λDNA and SV40ori-λDNA, respectively. The probability of occurrence of the local denaturation increased with negative superhelicity for both λDNA and SV40ori-λDNA.

YB-1 promotes transcription of cyclin D1 in human non-small-cell lung cancers.

Cyclin D1, an oncogenic G1 cyclin, and YB-1, a transcription factor involved in cell growth, are both over-expressed in several human cancers. In human lung cancer, the functional association between YB-1 and cyclin D1 has never been elucidated. In this study, we show YB-1 is involved in the transcription of cyclin D1 in human lung cancer. Depletion of endogenous YB-1 by siRNA inhibited progression of G1 phase and down-regulated both the protein and mRNA levels of cyclin D1 in human lung cancer cells. Forced over-expression of YB-1 with a cyclin D1 reporter plasmid increased luciferase activity, and ChIP assay results showed YB-1 bound to the cyclin D1 promoter. Moreover, the amount of YB-1 mRNA positively correlated with cyclin D1 mRNA levels in clinical non-small-cell lung cancer (NSCLC) specimens. Immunohistochemical analysis also indicated YB-1 expression correlated with cyclin D1 expression in NSCLC specimens. In addition, most of the cases expressing both cyclin D1 and CDC6, another molecule controlled by YB-1, had co-existing YB-1 over-expression. Together, our results suggest that aberrant expression of both cyclin D1 and CDC6 by YB-1 over-expression may collaboratively participate in lung carcinogenesis.

Amphiphilic Organic-Inorganic Hybrid Zeotype Aluminosilicate like a Nanoporous Crystallized Langmuir-Blodgett Film.

A new organic-inorganic hybrid zeotype compound with amphiphilic one-dimensional nanopore and aluminosilicate composition was developed. The framework structure is composed of double aluminosilicate layers and 12-ring nanopores; a hydrophilic layer pillared by Q(2) silicon atom species and a lipophilic layer pillared by phenylene groups are alternately stacked, and 12-ring nanopores perpendicularly penetrate the layers. The framework topology looks similar to that of an AFI-type zeolite but possesses a quasi-multidimensional pore structure consisting of a 12-ring channel and intersecting small pores equivalent to 8-rings. The hybrid material with alternately laminated lipophilic and hydrophilic nanospaces can be assumed as a crystallized Langmuir-Blodgett film. It demonstrates microporous adsorption for both hydrophilic and lipophilic adsorptives, and its outer surface tightly adsorbs lysozyme whose molecular size is much larger than its micropore opening. Our results suggest the possibility of designing porous adsorbent with high amphipathicity.

Real-time single-molecule observations of T7 Exonuclease activity in a microflow channel.

T7 Exonuclease (T7 Exo) DNA digestion reactions were studied using direct single-molecule observations in microflow channels. DNA digestion reactions were directly observed by staining template DNA double-stranded regions with SYTOX Orange and staining single-stranded (digested) regions with a fluorescently labeled ssDNA-recognizing peptide (ssBP-488). Sequentially acquired photographs demonstrated that a double-stranded region monotonously shortened as a single-stranded region monotonously increased from the free end during a DNA digestion reaction. Furthermore, DNA digestion reactions were directly observed both under pulse-chase conditions and under continuous buffer flow conditions with T7 Exo. Under pulse-chase conditions, the double-stranded regions of λDNA monotonously shortened by a DNA digestion reaction with a single T7 Exo molecule, with an estimated average DNA digestion rate of 5.7 bases/s and a processivity of 6692 bases. Under continuous buffer flow conditions with T7 Exo, some pauses were observed during a DNA digestion reaction and double-stranded regions shortened linearly except during these pauses. The average DNA digestion rate was estimated to be 5.3 bases/s with a processivity of 5072 bases. Thus, the use of our direct single-molecule observations using a fluorescently labeled ssDNA-recognizing peptide (ssBP-488) was an effective analytic method for investigating DNA metabolic processes.

RSPO fusion transcripts in colorectal cancer in Japanese population.

R-spondin (RSPO) gene fusions have recently been discovered in a subset of human colorectal cancer (CRC) in the U.S. population; however, whether the fusion is recurrent in CRC arising in patients from the other demographic areas and whether it is specific for CRC remain uncertain. In this study, we examined 75 primary CRCs and 121 primary lung cancers in the Japanese population for EIF3E-RSPO2 and PTPRK-RSPO3 fusion transcripts using RT-PCR and subsequent sequencing analyses. Although the expression of EIF3E-RSPO2 and PTPRK-RSPO3 was not detected in any of the lung carcinomas, RSPO fusions were detected in three (4%) of the 75 CRCs. Two CRCs contained EIF3E-RSPO2 fusion transcripts, and another CRC contained PTPRK-RSPO3 fusion transcripts. Interestingly, in one of the two EIF3E-RSPO2 fusion-positive CRCs, a novel fusion variant form of EIF3E-RSPO2 was identified: exon 1 of EIF3E was connected to exon 2 of RSPO2 by a 351-bp insertion. A quantitative RT-PCR analysis revealed that RSPO mRNA expression was upregulated in the three CRCs containing RSPO fusion transcripts, while it was downregulated in nearly all of the other CRCs. An immunohistochemical analysis and a mutational analysis revealed that the RSPO fusion-containing CRC had a CDX2 cell lineage, was positive for mismatch repair protein expression, and had the wild-type APC allele. Finally, the forced expression of RSPO fusion proteins were shown to endow colorectal cells with an increased growth ability. These results suggest that the expression of RSPO fusion transcripts is related to a subset of CRCs arising in the Japanese population.

A new direct single-molecule observation method for DNA synthesis reaction using fluorescent replication protein A.

Using a single-stranded region tracing system, single-molecule DNA synthesis reactions were directly observed in microflow channels. The direct single-molecule observations of DNA synthesis were labeled with a fusion protein consisting of the ssDNA-binding domain of a 70-kDa subunit of replication protein A and enhanced yellow fluorescent protein (RPA-YFP). Our method was suitable for measurement of DNA synthesis reaction rates with control of the ssλDNA form as stretched ssλDNA (+flow) and random coiled ssλDNA (-flow) via buffer flow. Sequentially captured photographs demonstrated that the synthesized region of an ssλDNA molecule monotonously increased with the reaction time. The DNA synthesis reaction rate of random coiled ssλDNA (-flow) was nearly the same as that measured in a previous ensemble molecule experiment (52 vs. 50 bases/s). This suggested that the random coiled form of DNA (-flow) reflected the DNA form in the bulk experiment in the case of DNA synthesis reactions. In addition, the DNA synthesis reaction rate of stretched ssλDNA (+flow) was approximately 75% higher than that of random coiled ssλDNA (-flow) (91 vs. 52 bases/s). The DNA synthesis reaction rate of the Klenow fragment (3'-5'exo-) was promoted by DNA stretching with buffer flow.