Functional analysis of basidiomycete specific chitin synthase genes in the agaricomycete fungus Pleurotus ostreatus

Chitin is an essential structural component of fungal cell walls composed of transmembrane proteins called chitin synthases (CHSs), which have a large range of reported effects in ascomycetes; however, are poorly understood in agaricomycetes. In this study, evolutionary and molecular genetic analyses of chs genes were conducted using genomic information from nine ascomycete and six basidiomycete species. The results support the existence of seven previously classified chs clades and the discovery of three novel basidiomycete-specific clades (BI-BIII). The agaricomycete fungus Pleurotus ostreatus was observed to have nine putative chs genes, four of which were basidiomycete-specific. Three of these basidiomycete specific genes were disrupted in the P. ostreatus 20b strain (ku80 disruptant) through homologous recombination and transformants were obtained (Δchsb2, Δchsb3, and Δchsb4). Despite numerous transformations Δchsb1 was unobtainable, suggesting disruption of this gene causes a crucial negative effect in P. ostreatus. Disruption of these chsb2-4 genes caused sparser mycelia with rougher surfaces and shorter aerial hyphae. They also caused increased sensitivity to cell wall and membrane stress, thinner cell walls, and overexpression of other chitin and glucan synthases. These genes have distinct roles in the structural formation of aerial hyphae and cell walls, which are important for understanding basidiomycete evolution in filamentous fungi.

Concomitant pancreatic and duodenal metastases 12 years after nephrectomy for renal cell carcinoma: a case report

In selected patients with metastatic renal cell carcinoma, metastasectomy can achieve prolonged survival. Herein we report a patient with concomitant pancreatic and duodenal metastases occurring 12 years after total right nephrectomy for a renal cell carcinoma. The metastases were successfully treated by a pancreas-sparing duodenectomy and distal pancreatectomy. A 66-year-old man was referred to our hospital with a chief complaint of right upper abdominal pain. He had undergone laparoscopic total right nephrectomy for renal cell carcinoma 12 years before. Enhanced computed tomography showed hypervascular tumors in the pancreatic body and the descending duodenum near the papilla of Vater. Histopathological examination of endoscopic ultrasonography-guided fine needle aspiration cytology specimens revealed metastatic clear cell renal cancer. The patient underwent pancreas-sparing duodenectomy and distal pancreatectomy. He developed a pancreatic fistula after surgery that improved with conservative treatment, and has been free of evidence of recurrence up to 20 months postoperatively.

Right paraduodenal hernia presenting with strangulated obstruction with intestinal malrotation: a case report

A paraduodenal hernia is a rare cause of an internal hernia that may require massive bowel resection; prompt diagnosis and surgical treatment are essential. In cases of malrotation, strangulation may occur both inside and outside the hernial sac. Strangulation outside the hernial sac makes the preoperative diagnosis more difficult. Herein, we report a patient with a right paraduodenal hernia, intestinal malrotation, and strangulation outside the hernia. An 86-year-old woman was admitted to our hospital with abdominal pain. Enhanced computed tomography showed a closed-loop obstruction of the hypo-enhancing small bowel and absence of a horizontal duodenal leg. The patient underwent an emergency laparotomy and was diagnosed with strangulated bowel obstruction due to a right paraduodenal hernia and malrotation. The patient underwent resection of the ischemic ileum, closure of the hernial orifice, and repositioning of the intestine. The postoperative course was uneventful. The patient reported no abdominal discomfort after 7 months of follow-up.

Features of disruption mutants of genes encoding for hydrophobin Vmh2 and Vmh3 in mycelial formation and resistance to environmental stress in Pleurotus ostreatus

Hydrophobins, which are small-secreted proteins with both hydrophobic and hydrophilic parts, can self-assemble into an amphiphilic film at the air-water interface, helping the fungus to form aerial hyphae. In the agaricomycete Pleurotus ostreatus, more than 20 putative hydrophobin genes have been predicted. Of these, two hydrophobin genes, vmh2 and vmh3, are predominantly expressed in the vegetative mycelium. In this study, we focused on the functions of Vmh2 and Vmh3 in vegetative mycelia. Based on the observation of the mycelial cross-section by transmission electron microscopy and the disappearance time of water droplets on the mycelial surface, Vmh2 and Vmh3 were considered essential for the maintenance of the surface hydrophobicity of the mycelium. The Δvmh3 and Δvmh2Δvmh3 strains exhibited relatively slower aerial mycelia formation on a liquid medium, and no significant alteration was observed in Δvmh2 strains. Only the Δvmh3 and Δvmh2Δvmh3 strains grew slower than the wild-type strain under stress conditions involving SDS and H2O2 on agar plates. This study revealed possible distinct roles for these hydrophobins in stress resistance. These results suggest that Agaricomycetes, including P. ostreatus, have evolved to possess multiple different hydrophobins as a means of adapting to various environments.

Physiological function of hydrophobin Vmh3 in lignin degradation by white-rot fungus Pleurotus ostreatus

Hydrophobins are small-secreted proteins comprising both hydrophobic and hydrophilic parts, that can self-assemble into an amphiphilic film at the air-liquid interface. More than 20 hydrophobin genes have been estimated in the white-rot fungus Pleurotus ostreatus. In our previous studies, three hydrophobin genes were shown to be predominantly expressed under ligninolytic conditions, and only vmh3 was downregulated in both the delignification-deficient mutant Δgat1 and Δhir1 strains. Here, we focused on the function of the hydrophobin Vmh3 to clarify its physiological role in lignin degradation. When the hyphae were observed by transmission electron microscopy, deletion of vmh3 resulted in the disappearance of black aggregates at the interface between the cell wall and outer environment. Deletion of vmh3 resulted in reduced hydrophobicity when 0.2% sodium dodecyl sulfate was dropped onto the mycelial surface. These results suggest that Vmh3 functions on the cell surface and plays a major role in mycelial hydrophobization. Furthermore, the Δvmh3 strain showed a marked delay in lignin degradation on beech wood sawdust medium, while the production of lignin-modifying enzymes was not reduced. This study demonstrated, for the first time, the possible effect of hydrophobin on lignin degradation by a white-rot fungus.

Synthesizing Complex Quaternary Carbons by the Sequence-Regulated Additions of tert-Alkyl Radicals to Two Different Olefins

We report the sequence-regulated radical additions of tert-alkyl radicals to two different olefins controlled by a Cu catalyst, which we term the "atom-transfer radical addition-substitution" reaction. The reactions of α-bromocarbonyl compounds, such as tert-alkyl radical sources, with methacrylates and styrenes occur in a sequence-regulated manner to give the corresponding three-component product possessing skipped quaternary carbon centers. Our method provides new insight into how to control the reactivities of tert-alkyl radicals during the synthesis of regulated aliphatic chains.

Long-Term Analysis of Internal Exposure Dose-Reduction Effects by Food Regulation and Food Item Contribution to Dose after the Fukushima Daiichi Nuclear Power Plant Accident

Over 10 years have passed since the Fukushima Daiichi Nuclear Power Plant accident. This study verifies the efficacy of longitudinal regulation on internal exposure doses and analyzes food group contributions to radiation doses using accumulated monitoring test results. The committed effective doses in 10,000 virtual persons from fiscal year (FY) 2012 to 2021, with and without regulation, were estimated as products of radioactivity concentrations randomly sampled from the test results, food intake, and dose coefficient. The distributed values of food intake rather than a mean value in dose estimation were assumed to reflect food intake variations and avoid underestimation of internal exposure doses for high-intake consumers. Furthermore, the ingestion of radioactive cesium from the calculation was analyzed per food group. The 95th percentile of the internal exposure dose (the dose of a “representative person”) was less than 1 mSv/year in both FYs. The regulation effect was substantial in FY 2012, and no noticeable difference in radiation doses was found between the regulation and no regulation conditions after FY 2016. Internal exposure doses decreased until approximately FY 2016 and then remained constant. It was also shown that not only radioactivity concentration but also food intake is a major factor affecting cesium intake. In summary, it was confirmed that Japan had ensured food safety regarding radioactive materials.

Device-Related Thrombotic Microangiopathy in an Elderly Patient With a History of Aortic Surgery

Thrombotic microangiopathy (TMA) is caused by several diseases, including infections, congenital and autoimmune diseases, and malignancies, usually requiring admission to intensive care. The primary pathophysiology of TMA is microvascular thrombosis, and its diagnosis is based on the presence of hemolysis, thrombocytopenia, schistocytes in a blood smear, and organ damage. Among secondary TMAs, device-related TMA could be difficult to diagnose if device implementation was performed years ago. We report the case of an 87-year-old woman with a chief complaint of dyspnea diagnosed with device-related TMA. In device-related TMA, thrombogenesis/thrombocytopenia is triggered by hemolysis/fragmented red blood cells. However, in other TMAs, thrombogenesis or thrombocytopenia is preceded by hemolysis and the presence of fragmented red blood cells. Thus, rapid plasma exchange is necessary to address TMA pathogenesis. TMA can be managed in a community hospital if the facility has access to plasma exchange. It is possible to treat complex TMAs even in community hospitals by carefully considering their pathophysiology. Additionally, improving the quality of general practice in community hospitals will allow for more effective diagnosis and treatment of TMAs.

Meiotic Silencing in Dothideomycetous Bipolaris maydis

The filamentous ascomycete Bipolaris maydis is a plant pathogen that causes corn leaf blight and has been used in cytological studies of sexual reproduction. In this fungus, when null mutants of each septin are crossed with the wild-type strain, all ascospores derived from the same asci show abnormal morphology. The phenomenon was remarkably similar to the event known as "ascus dominance" in Neurospora crassa, which is known to be caused by MSUD (meiotic silencing by unpaired DNA). However, it is not clear whether B. maydis possesses functional MSUD. The object of this study is to elucidate whether this fungus carries a functional MSUD system that causes ascus dominance in the crosses of septin mutants and the wild-type strain. The results of homozygous and heterozygous crossing tests with mutants, having the insertional CDC10-septin gene sequence into the genome, suggested that the ascus dominance in B. maydis is triggered by the unpaired DNA as in N. crassa. To investigate whether MSUD is caused by the same mechanism as in N. crassa, an RNA-dependent RNA polymerase, one of the essential factors in MSUD, was identified and disrupted (Δrdr1) in B. maydis. When the Δrdr1 strain was crossed with each mutant of the septins, ascus dominance did not occur in all crosses. These results suggest that this ascus dominance is caused by RNA silencing triggered by an unpaired gene, as in N. crassa, and septin genes were affected by this silencing. To date, although MSUD has been found only in Fusarium graminearum and N. crassa, which are classified as Sordariomycetes, this study showed that MSUD is also functional in B. maydis, which is classified as a Dothideomycete. These results showed the possibility that this posttranscriptional regulation is extensively conserved among filamentous ascomycetes.

Dynamic changes in RAS gene status in circulating tumour DNA: a phase II trial of first-line FOLFOXIRI plus bevacizumab for RAS-mutant metastatic colorectal cancer (JACCRO CC-11)

Background

Few prospective studies have used liquid biopsy testing in RAS-mutant metastatic colorectal cancer (mCRC), and its clinical significance remains unknown. Therefore, this study aimed to carry out a biomarker analysis by liquid biopsy using updated data of the phase II trial of FOLFOXIRI plus bevacizumab as first-line chemotherapy for RAS-mutant mCRC.

Materials and methods

A total of 64 patients who received modified FOLFOXIRI regimen (irinotecan 150 mg/m², oxaliplatin 85 mg/m², levofolinate 200 mg/m², and fluorouracil 2400 mg/m²) plus bevacizumab biweekly were enrolled. The primary endpoint was the objective response rate (ORR). Plasma samples were collected at pre-treatment, 8 weeks after treatment, and progression in participants included in the biomarker study. The levels of circulating tumour DNA (ctDNA) and specific KRAS and NRAS variants were evaluated using real-time PCR assays.

Results

There were 62 patients (median age: 62.5 years, 92% performance status 0, 27% right side) who were assessable for efficacy and 51 for biomarker analysis. ORR was 75.8% (95% confidence interval 65.1% to 86.5%). The median progression-free survival was 12.1 months, and the median overall survival (OS) was 30.2 months. In 78% of patients, RAS mutations disappeared in the ctDNA at 8 weeks after treatment; these patients tended to have better outcomes than those with RAS mutations. Interestingly, RAS mutations remained undetectable during progression in 62% of patients. Survival analysis indicated that the median OS from progression was significantly longer in patients with RAS mutation clearance than in those with RAS mutation in the ctDNA at disease progression (15.1 versus 7.3 months, hazard ratio: 0.21, P = 0.0046).

Conclusions

Our biomarker study demonstrated no RAS mutations in ctDNA at disease progression in 62% of patients with RAS-mutant mCRC. Both OS and post-progression survival were better in patients with clearance of RAS mutations in ctDNA after triplet-based chemotherapy.

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First-line FOLFOXIRI plus bevacizumab is effective for RAS-mutant mCRC with comparable efficacy in elderly patients.

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RAS mutations disappeared in ctDNA after intensive chemotherapy in 62% of patients with mCRC with RAS-mutant tumours.

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Survival time was longer in patients with RAS mutation clearance than in those with RAS mutations in ctDNA.

Related factors and changes of angiopoietin-like protein 2 with chronic heart failure patients participating in phase III cardiac rehabilitation

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): the research grant D2 from Kansai Medical University

Objectives

Angiopoietin-like protein 2 (ANGPTL2) is a protein, whose structure is similar to that of angiopoietin, but binds to a different receptor. Overexpression of ANGPTL2 promotes chronic inflammation and relates to the development of aging-related diseases. ANGPTL2 has been reported to be mainly secreted by adipose tissue. Although ANGPTL2 has been implicated in the pathogenesis of heart failure, there are no studies about serum ANGPTL2 levels in patients with heart failure participating in cardiac rehabilitation program. The aim of this study was to investigate the characteristics, related factors and changes of ANGPTL2 in patients with chronic heart failure during phase III of cardiac rehabilitation program.

Methods

The subjects included 57 patients (70.1 ± 10.2 years old; 46 men) with chronic heart failure whose serum ANGPTL2 levels were measured during the maintenance phase of cardiac rehabilitation program. Furthermore, we classified 25 patients (70.6 ± 7.5 years old; 23 men) from the 6-month course into a reduced group and an unchanged group to characterize change in ANGPTL2. We excluded patients who were admitted or discharged within 3 months of the evaluation of serum ANGPTL2. We evaluated exercise tolerance using the cardiopulmonary exercise test, grip strength, body composition using a body composition analyzer, blood examinations, and echocardiography. Serum ANGPTL2 was measured by solid-phase sandwich enzyme-linked immunosorbent assay (ELISA).

Results

The median value of ANGPTL2 was 4.05 ng/ml. ANGPTL2 was positively correlated with body weight, body mass index, body fat mass, body fat percentage, C-reactive protein (CRP) and total protein (TP) levels, and negatively correlated with skeletal muscle mass percentage and anaerobic threshold (AT). From the result of the logistic regression analysis, AT (OR=0.68, 95% CI:0.47-0.97and TP (OR=20.1, 95% CI:2.52-160.63) were extracted as independent factors related to the level of ANGPTL2. In addition, overall serum ANGPTL2 levels decreased significantly after 6 months. Changes in ANGPTL2 in the reduced group showed a positive correlation between baseline peak VO2, left ventricular ejection fraction and skeletal muscle rate, and a negative correlation with baseline ANGPTL2, CRP, body fat mass. In an unchanged group, HbA1c increased, but no significant change was observed in other factors.

Conclusions

Exercise tolerance in patients with chronic heart failure during maintenance phase might be related to the inflammation marker ANGPTL2. Serum ANGPTL2 levels with stable chronic heart failure patients decreased significantly 6 months after continued cardiac rehabilitation.

Ezrin Contributes to the Plasma Membrane Expression of PD-L1 in A2780 Cells

Programmed death ligand–1 (PD–L1) is one of the immune checkpoint molecule localized on the plasma membrane of numerous cancer cells that negatively regulates T-cell-mediated immunosurveillance. Despite the remarkable efficacy and safety profile of immune checkpoint inhibitors (ICIs), such as anti-PD–L1 antibodies, restricted poor therapeutic responses to ICIs are often observed in patients with ovarian cancer. Because higher expression of PD–L1 in advanced ovarian cancer is associated with a decreased survival rate, identifying the potential molecules to regulate the plasma membrane expression of PD–L1 may provide a novel therapeutic strategy to improve the efficacy of ICIs against ovarian cancers. Here, we reveal the involvement of the ezrin/radixin/moesin (ERM) family, which crosslinks transmembrane proteins with the actin cytoskeleton by serving as a scaffold protein, in the plasma membrane expression of PD–L1 in the human epithelial ovarian cancer cell line A2780. Our results demonstrate that PD–L1 and all three ERMs were expressed at the mRNA and protein levels in A2780 cells, and that PD–L1 was highly colocalized with ezrin and moesin, but moderately with radixin, in the plasma membrane. Interestingly, RNA interference-mediated gene silencing of ezrin, but not of radixin or moesin, substantially reduced the plasma membrane expression of PD–L1 without altering its mRNA expression. In conclusion, our results indicate that ezrin may be responsible for the plasma membrane expression of PD–L1, possibly by serving as a scaffold protein in A2780 cells. Ezrin is a potential therapeutic target for improving the efficacy of ICIs against ovarian cancers.

Tumor response of FOLFOXIRI plus cetuximab versus bevacizumab in RAS wild-type metastatic colorectal cancer: The subgroup-analysis of DEEPER trial (JACCRO CC-13)

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Background: Triplet regimen, FOLFOXIRI, combined with bevacizumab (bev) or panitumumab has been shown to be superior in terms of early tumor shrinkage and depth of response (DpR) compared to doublet combinations in patients with RAS wild-type metastatic colorectal cancer (mCRC). We performed a randomized phase II study, DEEPER trial (JACCRO CC-13)[NCT02515734], to investigate the efficacy and safety of cetuximab (cet) vs. bevacizumab (bev) in combination with modified (m)-FOLFOXIRI (irinotecan 150 mg/m2, oxaliplatin 85 mg/m2, 5-FU 2400 mg/m2) in previously untreated mCRC patients with RAS wild-type tumors (Tsuji A, et al. ASCO 2021). Methods: The primary endpoint was DpR during the entire course. Secondary endpoints included overall response rate (ORR), disease control rate, R0 resection rate, progression-free survival, and overall survival. A post-hoc subgroup analysis by PS, tumor sidedness, age, and location of metastases was performed to evaluate the efficacy of triplet plus cet vs. bev regimen. Results: A total of 359 patients were enrolled between July 2015 and June 2019. For the full analysis set (median age 65y, 64% male, PS0/1: 91%/9%, left/right primary: 83%/17%), 173 and 175 patients were randomly assigned to the cet and bev arms, respectively. Median DpR was 57.4% vs. 46.0% ( p = 0.001), and the ORR was 69.1% vs. 71.7% ( p = 0.60), in cet vs. bev, respectively. The subgroup analysis was present in the table. There was no significant difference in terms of ORR and R0 resection rate between groups according to PS, tumor sidedness, age, and liver metastases (LM). In patients with only LM, the R0 resection rate of cet vs. bev was 25.0% vs. 14.8% ( p = 0.21). Conclusions: The m-FOLFOXIRI plus cet showed to be significantly superior to the m-FOLFOXIRI plus bev in terms of DpR in first-line treatment for RAS wild-type mCRC. The better DpR of m-FOLFOXIRI plus cet was evident for RAS wild-type mCRC patients with left-sided tumors, LM or under 70 years old. Clinical trial information: UMIN000018217.[Table: see text]

Phase II Study of Preoperative Chemoradiotherapy With S-1 Plus Oxaliplatin for Locally Advanced Rectal Cancer (PerSeUS-RC01)

BACKGROUND/AIM

We report the end results of a study evaluating the safety and efficacy of preoperative chemoradiotherapy with S-1 plus oxaliplatin.

PATIENTS AND METHODS

Eligible patients had histopathologically confirmed locally advanced rectal carcinoma (LARC; cT3-T4, any N). They received oral S-1 (80 mg/m²/day on days 1-5, 8-12, 22-26, and 29-33) and oxaliplatin by infusion (50 mg/m²/day on days 1, 8, 22, and 29) along with radiotherapy (1.8 Gy/day, total dose: 45 Gy/25 fractions). A chemotherapy gap was included in the third week of radiotherapy. The study endpoint was pathological response rate (Grade 2, 3). Secondary endpoints included rates of pathologic complete response (pCR), R0 resection, disease-free survival (DFS), overall survival (OS), local and distant recurrence, and safety and relative dose intensity.

RESULTS

The study enrolled 23 patients at three Centres in Gifu, Japan. All patients received chemoradiotherapy, and 22 underwent surgery. Rates of pathological response, R0 resection, and pathological down-staging were 56.5% (13/23), 95.7% (22/23), and 63.6% (14/22), respectively. There were no grade 4 adverse events, but grade 3 events occurred in 21.7% of patients. The cumulative 3-year local recurrence rate was 8.7%. Distant metastasis occurred in 10 (43.5%) patients, 2 (8.7%) from local recurrence and 2 from secondary pancreatic cancer and lung cancer. There were 8 patients with lung metastasis, 2 with liver metastasis, one with ovarian metastasis, and one with bone metastasis. Three-year rates of DFS and OS were 51.1% (median follow-up 34.3 months) and 91.1% (45.2 months), respectively.

CONCLUSION

The study showed high pathological response rate without severe toxicity and good follow-up results. Unexpectedly, however, this regimen could not control local recurrence and distant metastasis. Nevertheless, adding oxaliplatin to preoperative chemoradiotherapy with S-1 in patients with LARC appears feasible and may safely result in better local control than standard treatment. The study suggests adding treatment with induction chemotherapy in consideration of CEA level and N factor.

An exocyst component, Sec5, is essential for ascospore formation in Bipolaris maydis

In this study, we identified Sec5 in Bipolaris maydis, a homologue of Sec5 in Saccharomyces cerevisiae and a possible exocyst component of the fungus. To examine how Sec5 affects the life cycle of B. maydis, we generated null mutant strains of the gene (Δsec5). The Δsec5 strains showed a strong reduction in hyphal growth and a slight reduction in pathogenicity. In sexual reproduction, they possessed the ability to develop pseudothecia. However, all ascospores were aborted in any of the asci obtained from crosses between Δsec5 and the wild-type. Our cytological study revealed that the abortion was caused by impairments of the post-meiotic stages in ascospore development, where ascospore delimitation and young spore elongation occur.

Ezrin Modulates the Cell Surface Expression of Programmed Cell Death Ligand-1 in Human Cervical Adenocarcinoma Cells

Cancer cells employ programmed cell death ligand-1 (PD-L1), an immune checkpoint protein that binds to programmed cell death-1 (PD-1) and is highly expressed in various cancers, including cervical carcinoma, to abolish T-cell-mediated immunosurveillance. Despite a key role of PD-L1 in various cancer cell types, the regulatory mechanism for PD-L1 expression is largely unknown. Understanding this mechanism could provide a novel strategy for cervical cancer therapy. Here, we investigated the influence of ezrin/radixin/moesin (ERM) family scaffold proteins, crosslinking the actin cytoskeleton and certain plasma membrane proteins, on the expression of PD-L1 in HeLa cells. Our results showed that all proteins were expressed at mRNA and protein levels and that all ERM proteins were highly colocalized with PD-L1 in the plasma membrane. Interestingly, immunoprecipitation assay results demonstrated that PD-L1 interacted with ERM as well as actin cytoskeleton proteins. Furthermore, gene silencing of ezrin, but not radixin and moesin, remarkably decreased the protein expression of PD-L1 without affecting its mRNA expression. In conclusion, ezrin may function as a scaffold protein for PD-L1; regulate PD-L1 protein expression, possibly via post-translational modification in HeLa cells; and serve as a potential therapeutic target for cervical cancer, improving the current immune checkpoint blockade therapy.

Downregulation of the ypdA Gene Encoding an Intermediate of His-Asp Phosphorelay Signaling in Aspergillus nidulans Induces the Same Cellular Effects as the Phenylpyrrole Fungicide Fludioxonil

Many eukaryotic histidine-to-aspartate (His-Asp) phosphorelay systems consist of three types of signal transducers: a His-kinase (HK), a response regulator (RR), and a histidine-containing phosphotransfer intermediate (HPt). In general, the HPt acts as an intermediate between the HK and the RR and is indispensable for inducing appropriate responses to environmental stresses. In a previous study, we attempted but were unable to obtain deletion mutants of the ypdA gene in order to characterize its function in the filamentous fungus Aspergillus nidulans. In the present study, we constructed the CypdA strain in which ypdA expression is conditionally regulated by the A. nidulans alcA promoter. We constructed CypdA strains with RR gene disruptions (CypdA-sskAΔ, CypdA-srrAΔ, and CypdA-sskAΔsrrAΔ). Suppression of YpdA induced by ypdA downregulation activated the downstream HogA mitogen-activated protein kinase cascade. YpdA suppression caused severe growth defects and abnormal hyphae, with features such as enhanced septation, a decrease in number of nuclei, nuclear fragmentation, and hypertrophy of vacuoles, both regulated in an SskA-dependent manner. Fludioxonil treatment caused the same cellular responses as ypdA suppression. The growth-inhibitory effects of fludioxonil and the lethality caused by ypdA downregulation may be caused by the same or similar mechanisms and to be dependent on both the SskA and SrrA pathways.

Role of Ezrin/Radixin/Moesin in the Surface Localization of Programmed Cell Death Ligand-1 in Human Colon Adenocarcinoma LS180 Cells

Programmed cell death ligand-1 (PD-L1), an immune checkpoint protein highly expressed on the cell surface in various cancer cell types, binds to programmed cell death-1 (PD-1), leading to T-cell dysfunction and tumor survival. Despite clinical successes of PD-1/PD-L1 blockade therapies, patients with colorectal cancer (CRC) receive little benefit because most cases respond poorly. Because high PD-L1 expression is associated with immune evasion and poor prognosis in CRC patients, identifying potential modulators for the plasma membrane localization of PD-L1 may represent a novel therapeutic strategy for enhancing the efficacy of PD-1/PD-L1 blockade therapies. Here, we investigated whether PD-L1 expression in human colorectal adenocarcinoma cells (LS180) is affected by ezrin/radixin/moesin (ERM), functioning as scaffold proteins that crosslink plasma membrane proteins with the actin cytoskeleton. We observed colocalization of PD-L1 with all three ERM proteins in the plasma membrane and detected interactions involving PD-L1, the three ERM proteins, and the actin cytoskeleton. Furthermore, gene silencing of ezrin and radixin, but not of moesin, substantially decreased the expression of PD-L1 on the cell surface without affecting its mRNA level. Thus, in LS180 cells, ezrin and radixin may function as scaffold proteins mediating the plasma membrane localization of PD-L1, possibly by post-translational modification.

POS0887 TRANSCRANIAL ELECTRICAL STIMULATION IS SAFE AND EFFICIENT IN PATIENTS WITH SYSTEMIC AUTOIMMUNE MYOPATHIES

Background:

There is currently few information regarding rehabilitation in patients with systemic autoimmune myopathies (SAMs). Transcranial direct current stimulation (tDCS) has shown promising results for the motor performance of healthy individuals as for patients with, e.g., post-stroke hemiparetic limbs.

Objectives:

The present study was aimed to assessing the safety and efficiency of tDCS in patients with SAMs.

Methods:

This study is a prospective, randomized, sham controlled, double blind, and clinical trial with ethical approval. Eighteen adult patients with dermatomyositis, polymyositis, antisynthetase syndrome or immune-mediated necrotizing myopathies in remission or with minimal disease activity were enrolled from 2018 to 2019. Patients were allocated randomly in two groups to receive sham or active tDCS with 2mA amplitude submitted for 20 minutes for three consecutive days. The 5x7cm sponge-electrodes were positioned with the anode over the left (C1) or right (C2) - contralateral to the dominant limb, whereas the cathode over the FP2 or FP3, respectively (10-10 EEG electrodes placement). The groups were evaluated in four moments: pre-stimulation, and 30 minutes, 3 weeks and 8 weeks post-tDCS. They were evaluated in the different moments with International Myositis Assessment and Clinical Studies Group set scores, Short-Form health survey (SF-36), state-trait anxiety inventory (STAI), Beck depression inventory (BDI), timed up-and-go test (TUG), time-stands test (TST), isokinetic extension and flexion testing of bilateral knee and elbow. A specific security questionnaire for tDCS was used after the active or sham stimulation in all patients.

Results:

The demographic data, kind of myositis, disease duration, and disease status (all with low disease activity) were comparable between both active and sham tDCS groups. After interventions, there was improvement of values of patient’s VAS (P=0.042) and serum levels of creatine phosphokinase (P=0.005), independent of the group. Moreover, in active tDCS group, the physical aspects of SF-36 in week 8 (P<0.001), mean and better TST at each evaluation (P<0.001), absolute peak tork (P<0.001) and peak tork adjusted for body weight values (P<0.001) of stimulated inferior limb extension also improved. No differences were observed in the STAI, BDI, or TUG in both groups. The patients’ adherence to the protocol was 100% and no adverse event was reported, including disease relapsing.

Conclusion:

This unprecedented study evidences the safety of tDCS, besides the potential efficiency in improving rehabilitation of tDCS in SAMs. More studies with a large samples and period of tDCS sessions are necessaries to corroborate with the present study.

References:

[1]Lundberg IE, et al. 2017 European league against rheumatism/ American College of Rheumatology classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups. Arthritis Rheum. 2017;69:2271-82.

[2]Tanaka S, et al. Single session of transcranial direct current stimulation transiently increases knee extensor force in patients with hemiparetic stroke. Neurorehabil Neural Repair. 2011;25:565-9.

Acknowledgements:

This work was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) 303.379/2018-9, Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) 2019/11776-6, Faculdade de Medicina da USP/SP to SKS.

Disclosure of Interests:

None declared

Subcellular distribution of ezrin/radixin/moesin and their roles in the cell surface localization and transport function of P-glycoprotein in human colon adenocarcinoma LS180 cells

The ezrin/radixin/moesin (ERM) family proteins act as linkers between the actin cytoskeleton and P-glycoprotein (P-gp) and regulate the plasma membrane localization and functionality of the latter in various cancer cells. Notably, P-gp overexpression in the plasma membrane of cancer cells is a principal factor responsible for multidrug resistance and drug-induced mutagenesis. However, it remains unknown whether the ERM proteins contribute to the plasma membrane localization and transport function of P-gp in human colorectal cancer cells in which the subcellular localization of ERM has yet to be determined. This study aimed to determine the gene expression patterns and subcellular localization of ERM and P-gp and investigate the role of ERM proteins in the plasma membrane localization and transport function of P-gp using the human colon adenocarcinoma cell line LS180. Using real-time reverse transcription polymerase chain reaction and immunofluorescence analyses, we showed higher levels of ezrin and moesin mRNAs than those of radixin mRNA in these cells and preferential distribution of all three ERM proteins on the plasma membrane. The ERM proteins were highly colocalized with P-gp. Additionally, we show that the knockdown of ezrin, but not of radixin and moesin, by RNA interference significantly decreased the cell surface expression of P-gp in LS180 cells without affecting the mRNA expression of P-gp. Furthermore, gene silencing of ezrin substantially increased the intracellular accumulation of rhodamine123, a typical P-gp substrate, with no alterations in the plasma membrane permeability of Evans blue, a passive transport marker. In conclusion, ezrin may primarily regulate the cell surface localization and transport function of P-gp as a scaffold protein without influencing the transcriptional activity of P-gp in LS180 cells. These findings should be relevant for treating colorectal cancer, which is the second leading cause of cancer-related deaths in males and females combined.

Spontaneous esophageal rupture managed with endoscopic closure using an over-the-scope clip: A case report

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Spontaneous esophageal rupture is usually treated surgically.

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However, endoscopic interventions can be performed with good outcomes.

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Approach is based on degree of infection in the mediastinum and thoracic cavity.

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We used an over-the-scope clip for esophageal rupture localized to mediastinum.

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The esophageal perforation was closed once the inflammatory response subsided.

Introduction and importance

Spontaneous esophageal rupture is a life-threatening condition caused by a sudden increase in the intraesophageal pressure. While surgery is the mainstay of management for spontaneous esophageal ruptures, in recent years, an increasing number of patients have been managed with endoscopic interventions. We report a case of spontaneous esophageal rupture managed with endoscopic closure using an over-the-scope clip (Ovesco Endoscopy AG, Tübingen, Germany).

Case presentation

A 68-year-old female presented with epigastric pain and left-sided back pain following vomiting. A computed tomography scan revealed mediastinal emphysema and an esophagogram showed leakage from the left side of the lower thoracic esophagus into the mediastinum. The patient was diagnosed with spontaneous esophageal rupture localized to the mediastinum and was treated conservatively. However, she had persistent fever and continuing esophageal leakage on the esophagogram. On the 12th day of admission, a gastrointestinal endoscopy was performed, which found a 10-mm full-thickness longitudinal laceration on the left side of the lower esophagus. Endoscopic closure using an over-the-scope clip was performed. The next day, the patient became afebrile. One week later, esophagogram revealed slight residual leakage and an additional endoscopic closure using an over-the-scope clip was performed; the patient subsequently had an uneventful recovery and was discharged on the 44th day of admission.

Clinical discussion

Endoscopic closure using an over-the-scope clip led to a good outcome in this patient with spontaneous esophageal rupture.

Conclusion

Endoscopic closure using an over-the-scope clip is an effective and minimally invasive technique for selected patients with spontaneous esophageal rupture.

An arabinose-induced enhancement of asexual reproduction and concomitant changes in metabolic state in the filamentous fungus Bipolaris maydis

l-Arabinose, a major constituent pentose of plant cell-wall polysaccharides, has been suggested to be a less preferred carbon source for fungi but to be a potential signalling molecule that can cause distinct genome-wide transcriptional changes in fungal cells. Here, we explore the possibility that this unique pentose influences the morphological characteristics of the phytopathogenic fungus Bipolaris maydis strain HITO7711. When grown on plate media under different sugar conditions, the mycelial dry weight of cultures on l-arabinose was as low as that with no sugar, suggesting that l-arabinose does not substantially contribute to vegetative growth. However, the intensity of conidiation on l-arabinose was comparable to or even higher than that on d-glucose and on d-xylose, in contrast to the poor conidiation under the no-sugar condition. To explore the physiological basis of the passive growth and active conidiation on l-arabinose, we next investigated cellular responses of the fungus to these sugar conditions. Transcriptional analysis of genes related to carbohydrate metabolism showed that l-arabinose stimulates carbohydrate utilization through the hexose monophosphate shunt (HMP shunt), a catabolic pathway parallel to glycolysis and which participates in the generation of the reducing agent NADPH (the reduced form of nicotinamide adenine dinucleotide phosphate). Then, the HMP shunt was impaired by disrupting the related gene BmZwf1, which encodes glucose-6-phosphate dehydrogenase in this fungus. The resulting mutants on l-arabinose showed remarkably decreased conidiation, but a conversely increased mycelial dry weight compared with the wild-type. Our study demonstrates that l-arabinose acts to enhance resource allocation to asexual reproduction in B. maydis HITO7711 at the cost of vegetative growth, and suggests that this is mediated by the concomitant stimulation of the HMP shunt.

Final results of the ACTS-CC 02 trial: A randomized phase III trial of S-1/oxaliplatin (SOX) versus UFT/leucovorin as adjuvant chemotherapy for high-risk stage III colon cancer

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Background: As previously reported (Sunami E, et al. Clin Colorectal Cancer. 2020), the ACTS-CC 02 trial demonstrated that S-1 and oxaliplatin (SOX) was not superior to UFT/leucovorin (LV) in terms of disease-free survival (DFS) as adjuvant chemotherapy for high-risk stage III colon cancer (any T, N2, or positive nodes around the origin of the feeding arteries). We now report the final overall survival (OS) after a median follow-up of more than 6 years. Methods: A total of 966 patients with high-risk stage III colon cancer were randomly assigned to receive either UFT/LV (300–600 mg/day of UFT according to body surface area [BSA] and 75 mg/day of LV on days 1-28, every 35 days, 5 courses) or SOX (100 mg/m2 of oxaliplatin on day 1 and 80–120 mg/day of S-1 according to BSA on days 1-14, every 21 days, 8 courses). The primary endpoint was DFS. Patients’ data were updated in February 2020. Results: The subjects of this final efficacy analysis were 955 patients (478 in the UFT/LV group and 477 in the SOX group). Totally, Stage IIIA/IIIB/IIIC were 1.3%/50.2%/48.6% and T1/2/3/4 were 1.5%/4.0%/61.8%/32.7%. With median follow-up time of 74.3 months, the 5-year OS rate was 78.3% in the UFT/LV group and 79.1% in the SOX group (HR: 0.97; 95% CI: 0.76-1.24; p = 0.8175). The 5-year DFS rate was 55.2% in the UFT/LV group and 58.1% in the SOX group (HR: 0.92; 95% CI: 0.76-1.11; p = 0.3973). In an exploratory analysis, the 5-year OS rate in patients with T4 disease was 65.2% and 70.8% in the UFT/LV group and SOX group, respectively (HR: 0.81; 95% CI: 0.56-1.17), and the 5-year DFS rate was 45.4% and 50.5% (HR: 0.87; 95% CI: 0.65-1.19), respectively. Notably, in patients with T4N2b disease, the 5-year OS rate was 51.0% and 64.1% in the UFT/LV group and SOX group, (HR: 0.72; 95% CI: 0.40-1.31) and the 5-year DFS rate was 31.1% and 37.2% (HR: 0.87; 95% CI: 0.50-1.31), respectively. Conclusions: In Japanese patients with high-risk stage III colon cancer, the 5-year OS rate was similar in the UFT/LV group and SOX group. However, the oxaliplatin-based regimen was suggested to be more effective for DFS and OS in patients with advanced disease, such as T4N2b. Clinical trial information: JapicCTI-101073.