Mebamamide C, a deoxy analogue of mebamamides in Bryopsis marine green algae and Elysia sacoglossan mollusks

Kahalalides, originally isolated from the sacoglossan mollusk Elysia rufescens, have been found in various Elysia and Bryopsis species, with over 20 variants identified to date. These compounds are biosynthesized by Candidatus Endobryopsis kahalalidefaciens within Bryopsis species. In this study, we report the isolation and structural determination of a new cyclic depsipeptide, mebamamide C (1), from Bryopsis sp. The planar structure was determined by spectroscopic data analyses, and the absolute configurations were determined using Marfey's method and modified Mosher's method. Additionally, our study explores the chemical relationship between Bryopsis algae and Elysia mollusks. The individual chemical profiles of these marine organisms highlight a fascinating aspect of marine chemical ecology. The distinct, species-specific chemical profiles observed in Elysia species imply the possibility of a symbiotic relationship with the kahalalide-producing bacteria.

Biomechanical comparison of titanium alloy additively manufactured and conventionally manufactured plate-screw constructs

AIM

To biomechanically compare the bending stiffness, strength, and cyclic fatigue of titanium additively manufactured (AM) and conventionally manufactured (CM) limited contact plates (LCP) of equivalent dimensions using plate-screw constructs.

METHODS

Twenty-four 1.5/2.0-mm plate constructs (CM: n = 12; AM: n = 12) were placed under 4-point bending conditions. Data were collected during quasi-static single cycle to failure and cyclic fatigue testing until implants plastically deformed or failed. Bending stiffness, bending structural stiffness, and bending strength were determined from load-displacement curves. Fatigue life was determined as number of cycles to failure. Median test variables for each method were compared using the Wilcoxon rank sum test within each group. Fatigue data was also analysed by the Kaplan-Meier estimator of survival function.

RESULTS

There was no evidence for a difference in bending stiffness and bending structural stiffness between AM and CM constructs. However, AM constructs exhibited greater bending strength (median 3.07 (min 3.0, max 3.4) Nm) under quasi-static 4-point bending than the CM constructs (median 2.57 (min 2.5, max 2.6) Nm, p = 0.006). Number of cycles to failure under dynamic 4-point bending was higher for the CM constructs (median 164,272 (min 73,557, max 250,000) cycles) than the AM constructs (median 18,704 (min 14,427, max 33,228) cycles; p = 0.02). Survival analysis showed that 50% of AM plates failed by 18,842 cycles, while 50% CM plates failed by 78,543 cycles.

CONCLUSION AND CLINICAL RELEVANCE

Additively manufactured titanium implants, printed to replicate a conventional titanium orthopaedic plate, were more prone to failure in a shorter fatigue period despite being stronger in single cycle to failure. Patient-specific implants made using this process may be brittle and therefore not comparable to CM orthopaedic implants. Careful selection of their use on a case/patient-specific basis is recommended.

Structure Determination of Kahalalide Analogues Based on Metagenomic Analysis of a Bryopsis sp. Marine Green Alga

Two kahalalide analogues were isolated from a Bryopsis sp. marine green alga. Even though our initial structure determination of the peptides by NMR and MS identified them as kahalalide Z1 (KZ1; 3) and Z2 (KZ2; 4), the absolute configuration of the Thr residues by Marfey's analysis was different from those found in kahalalide F (KF), 3, and 4. To ascertain the absolute configuration of the amino acid residues genetically, we conducted a metagenomic analysis for symbiotic bacteria in the alga, leading to the biosynthetic gene cluster (BGC) responsible for producing the kahalalides named kahalalides Z3 (KZ3; 1) and Z4 (KZ4; 2). The identification of amino acid residues based on the A-domain suggested these peptides possess the amino acid sequence d-allo-Thr-l-Val-l-Val-d-Val residues at the N-terminus, instead of the d-Val-l-Thr-l-Val-d-Val residues found in KF, 3, and 4. The N-terminal amino acid sequence including absolute configuration was unambiguously determined by a comparison of LCMS data of synthetic tetrapeptides and the hydrolysates derived from 1 and 2. This structural difference is caused by swapping the substrate specificities of the first two A-domains.

Maternal protein restriction induces renal AT2R promoter hypomethylation in salt-sensitive, hypertensive rats

SCOPE

We previously demonstrated that protein restriction in utero induced salt-sensitive hypertension and changed renal levels of angiotensin type 2 receptor (AT2R) in Stroke-Prone Spontaneously Hypertensive Rat (SHRSP). Here, we investigated if this characteristic alteration of AT2R is related to AT2R DNA methylation profiles.

METHODS AND RESULTS

First, we examined the relation between AT2R DNA methylation and its promoter activity in vitro. Luciferase assays revealed a negative correlation between these two variables. Next, we fed SHRSP dams and grand-dams a control 20% casein diet or a 9% casein diet during pregnancy. Adult offspring and grand-offspring were supplied either water or 1% saline solution for 2 weeks. Renal AT2R promoter DNA near the TATA-box was hypomethylated, mRNA expression was suppressed, and protein expression tended to be higher, in adult offspring of mothers fed a low casein diet. Moreover, adult grand-offspring exhibited high blood pressure after salt loading, along with suppressed transcription of AT2R mRNA and elevated translated protein.

CONCLUSIONS

Under a fetal environment of protein restriction, the increase in protein expression due to hypomethylation of the AT2R promoter region occurs as a response to increased salt sensitivity, and controlling this mechanism may be important for the prevention of hypertension.

Erlotinib plus bevacizumab vs erlotinib monotherapy as first-line treatment for advanced EGFR mutation-positive non-squamous non-small-cell lung cancer: Survival follow-up results of the randomized JO25567 study

OBJECTIVES

The JO25567 randomized Phase II study demonstrated a statistically significant progression-free survival (PFS) benefit with erlotinib plus bevacizumab compared with erlotinib monotherapy in chemotherapy-naïve Japanese patients with epidermal growth factor receptor mutation-positive (EGFR+) non-small-cell lung cancer (NSCLC). Here we present updated PFS and final overall survival (OS) data after a median follow-up of 34.7 months.

MATERIALS AND METHODS

Patients with stage IIIB/IV or postoperative recurrent NSCLC were randomized to receive oral erlotinib 150 mg once daily (n = 77) or erlotinib in combination with intravenous bevacizumab 15 mg/kg every 21 days (n = 75) until disease progression or unacceptable toxicity. OS was analyzed using an unstratified Cox proportional hazards model.

RESULTS

Consistent with the primary analysis, addition of bevacizumab to erlotinib was associated with a significant improvement in PFS (hazard ratio [HR] 0.52; 95 % confidence interval [CI]: 0.35-0.76; log-rank two-sided P = 0.0005; median 16.4 months vs 9.8 months, respectively). In contrast, a significant improvement in OS was not seen (HR 0.81; 95 % CI, 0.53-1.23; P =  0.3267; median 47.0 months vs 47.4 months, respectively). Post-study therapy was similar between the treatment arms and EGFR mutation type did not affect OS outcomes. The 5-year OS rate was numerically higher with erlotinib plus bevacizumab vs erlotinib monotherapy (41 % vs 35 %). Updated safety analyses confirmed the previously reported manageable tolerability profile, with no new safety issues.

CONCLUSION

Addition of bevacizumab to first-line erlotinib did not show significant improvement in OS in Japanese patients with stage IIIB/IV or postoperative recurrent EGFR+ NSCLC. Both treatment arms showed a similar median OS benefit (as long as 4 years), irrespective of individual patient characteristics. Results from ongoing studies evaluating the combination of EGFR and VEGF signaling inhibitors are eagerly awaited.

TRIAL REGISTRATION

JapicCTI-111390 and JapicCTI-142569.

Relationship between cardiac magnetic resonance derived extracellular volume fraction and myocardial strain in patients with non-ischemic dilated cardiomyopathy

Background

The feature tracking (FT) technique has been proposed as a robust method to evaluate the myocardial strain using conventional cine magnetic resonance imaging (MRI) of the left ventricle. Data is limited regarding the relationship between FT-derived myocardial strain and diffuse myocardial fibrosis evaluated by T1 mapping in patients with non-ischemic dilated cardiomyopathy (NIDCM).

Purpose

The aim of this study was to evaluate the correlation between extracellular volume (ECV) by T1 mapping and myocardial strain by FT in patients with NIDCM.

Methods

A total of sixty-four patients with NIDCM (62±12 years) and 15 controls (62±11 years) were studied. Using a 1.5T MR scanner, pre- and post- T1 mapping images of LV wall at mid-ventricular level was acquired to calculate ECV by modified Look-Locker inversion recovery (MOLLI) sequence. Radial strain (RS), circumferential strain (CS) and longitudinal strain (LS) was assessed by FT technique. ECV and myocardial strain were compared using a 6-segment model at mid-ventricular level.

Results

Compared to the controls, the NIDCM patients had a significantly higher ECV (0.30±0.02 vs. 0.24±0.01, p<0.001) and impaired myocardial strain (RS, 24.2±3.0 vs. 52.2±6.2, p<0.001; CS, −7.5±2.1 vs. −15.3±2.2, p<0.001; LS −10.4±3.5 vs. −20.2±4.7, p<0.001, respectively). Similar results were obtained when comparing all 6 myocardial segments (segment 7–12) (all p values <0.001). In a segment-based analysis, a significant positive correlation was found between the ECV and CS (r=0.26 to 0.41; all p values <0.05), a negative correlation was found between the ECV and RS (r=−0.31 to −0.41; all p values <0.05). In a patient-based analysis, there were significant positive correlations between the ECV and CS (r=0.45, p<0.001), ECV and LS from 2-chamber view (r=0.30, p=0.006), ECV and LS from 4-chamber view (r=0.37, p<0.001). There was a significant negative correlation between the ECV and RS (r=−0.43, p<0.001) (FIGURE)

Conclusions

In NIDCM patients, severity of myocardial fibrosis evaluated by T1 mapping is associated with impaired myocardial strain by FT technique.

Correlation between the ECV and strain

Funding Acknowledgement

Type of funding source: None

Extracellular volume fraction by T1 mapping predicts omprovement of left ventricular ejection fraction after catheter ablation in patients with non-ischemic cardiomyopathy and atrial fibrillation

Background

The Catheter Ablation versus Standard Conventional Therapy in Patients with Left Ventricular Dysfunction and Atrial Fibrillation (CASTLE-AF) trial has shown that the catheter ablation (CA) for atrial fibrillation (AF) significantly reduced the risk of death and hospitalization for heart failure in patients with non-ischemic dilated cardiomyopathy (NIDCM) and AF (N Engl J Med 2018; 378:417–27). In addition, the Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation and Systolic Dysfunction (CAMERA-MRI) study demonstrated that the absence of myocardial fibrosis on late gadolinium enhanced (LGE) magnetic resonance imaging (MRI) is associated with improvement of left ventricular systolic function after CA in NIDCM patients with AF (J Am Coll Cardiol 2017; 70:1949–61). Extracellular volume fraction (ECV) by T1 mapping has emerges as a non-invasive mean to quantify diffuse myocardial fibrosis.

Purpose

The aim of this study was to compare the predictive value of LGE-MRI and ECV by T1 mapping for the prediction of improvement of LVEF after CA in NIDCM patients.

Methods

A total of twenty-eight patients with NIDCM and AF (age: 67±10 years; 25 (89%) male; LVEF: 34.1±8.8%) were studied. Using a 1.5T MR scanner and 32 channel cardiac coils, cine MRI, LGE-MRI, pre- and post- T1 mapping images of LV wall at mid-ventricular level (modified Look-Locker inversion recovery sequence) were acquired. Myocardial fibrosis on LGE was defined as area with >5SD signal intensity of normal myocardium. ECV from six segments of mid ventricular level were averaged for each patient. All patients underwent CA for AF, and the improvement of LVEF before and after CA were evaluated by echocardiography.

Results

All patients restored sinus rhythm after CA at the time of echocardiography. The mean LVEF was 34.1±8.8% before CA and 49.1±12.0% after CA (p<0.001), resulting an improvement of 15.0±11.8%. Significant correlation was found between improvements in LVEF and amount of fibrosis on LGE-MRI (r=−0.40, p=0.034), improvement of LVEF and ECV (r=−0.55, p=0.008). In the ROC analysis, ECV had a higher discriminative ability for the improvement of LVEF after CA compared with amount of fibrosis on LGE-MRI (AUC 0.885 vs 0.650) (Figure).

Conclusions

In NIDCM patients with AF, ECV by T1 mapping had better predictive ability for improvement of LVEF after CA in comparison to LGE-MRI.

ROC curves of ECV and LGE-MRI

Funding Acknowledgement

Type of funding source: None

Three multi-allelic gene pairs are responsible for self-sterility in the ascidian Ciona intestinalis

Many hermaphroditic organisms possess a self-incompatibility system to avoid inbreeding. Although the mechanisms of self-incompatibility in flowering plants are well known, little is known about the mechanisms of self-sterility in hermaphroditic marine invertebrates. Ascidians are hermaphroditic sessile marine invertebrates that release sperm and eggs into the surrounding seawater. Several species, including Ciona intestinalis type A (Ciona robusta), exhibit strict self-sterility. In a previous study, we found that the candidate genes responsible for self-sterility in Ciona reside in chromosome 2q (locus A) and chromosome 7q (locus B). Two pairs of multi-allelic genes, named s(sperm)-Themis-A and v(vitelline-coat)-Themis-A in locus A and s-Themis-B and v-Themis-B in locus B, are responsible for self-sterility. In this study, we identified a third multi-allelic gene pair, s-Themis-B2 and v-Themis-B2, within locus B that is also involved in this system. Genetic analysis revealed that the haplotypes of s/v-Themis-A, s/v-Themis-B and s/v-Themis-B2 play essential roles in self-sterility. When three haplotypes were matched between s-Themis and v-Themis, fertilization never occurred even in nonself crossing. Interestingly, gene targeting of either s/v-Themis-B/B2 or s/v-Themis-A by genome editing enabled self-fertilization. These results indicate that s/v-Themis-A, -B and -B2 are S-determinant genes responsible for self-sterility in the ascidian C. intestinalis type A.

Identification of GA-Binding Protein Transcription Factor Alpha Subunit (GABPA) as a Novel Bookmarking Factor

Mitotic bookmarking constitutes a mechanism for transmitting transcriptional patterns through cell division. Bookmarking factors, comprising a subset of transcription factors (TFs), and multiple histone modifications retained in mitotic chromatin facilitate reactivation of transcription in the early G1 phase. However, the specific TFs that act as bookmarking factors remain largely unknown. Previously, we identified the "early G1 genes" and screened TFs that were predicted to bind to the upstream region of these genes, then identified GA-binding protein transcription factor alpha subunit (GABPA) and Sp1 transcription factor (SP1) as candidate bookmarking factors. Here we show that GABPA and multiple histone acetylation marks such as H3K9/14AC, H3K27AC, and H4K5AC are maintained at specific genomic sites in mitosis. During the M/G1 transition, the levels of these histone acetylations at the upstream regions of genes bound by GABPA in mitosis are decreased. Upon depletion of GABPA, levels of histone acetylation, especially H4K5AC, at several gene regions are increased, along with transcriptional induction at 1 h after release. Therefore, we proposed that GABPA cooperates with the states of histone acetylation to act as a novel bookmarking factor which, may negatively regulate transcription during the early G1 phase.

The dynamics of granular flow from a silo with two symmetric openings

The dynamics of granular flow in a rectangular silo with two symmetrically placed exit openings is investigated using particle image velocimetry (PIV), flow rate measurements and discrete element modelling (DEM). The flow of mustard seeds in a Perspex silo is recorded using a high-speed camera and the resulting image frames are analysed using PIV to obtain velocity, velocity divergence and shear rate plots. A change in flow structure is observed as the distance L between the two openings is varied. The mass flow rate is shown to be at a maximum at zero opening separation, decreasing as L is increased; it then reaches a minimum before rising to an equilibrium rate close to two times that of an isolated (non-interacting) opening. The flow rate experiment is repeated using amaranth and screened sand and similar behaviour is observed. Although this result is in contrast with some recent DEM and physical experiments in silo systems, this effect has been reported in an analogous system: the evacuation of pedestrians from a room through two doors. Our experimental results are replicated using DEM and we show that inter-particle friction controls the flow rate behaviour and explains the discrepancies in the literature results.

NF-κB activation is an early event of changes in gene regulation for acquiring drug resistance in human adenocarcinoma PC-9 cells

Gefitinib and erlotinib are epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs). Although EGFR-TKIs are effective as anti-cancer drugs, cancer cells sometimes gain tolerance to the drugs. Previous studies suggested that the fibroblast growth factor receptor (FGFR)-signaling pathway could serve as compensation for the EGFR-signaling pathway inhibited by EGFR-TKIs. Our study further suggested that FGF2, a FGFR ligand, leaked out from naïve cells killed by gefitinib could initiate the FGFR-signaling pathway in surviving cells; i.e., altruistic survival may occur in naïve cells immediately after EGFR-TKI treatment. Altruistic survival may be temporal, and cells need to change their gene regulation toward gaining resistance to EGFR-TKIs. Changes in such gene regulation after EGFR-TKI treatment are poorly understood. In this study, we examined early events of such gene regulation changes in human adenocarcinoma PC-9 cells that are capable of changing their nature from susceptibility to resistance to EFGR-TKIs. Our study indicated that activation of nuclear factor-kappa B (NF-κB) occurred in the cells immediately after EGFR-TKI treatment and also by gene silencing against oncogenic EGFR; and, MG132 treatment for inhibiting NF-κB activation affected cell viability. Taken together, our findings (including the previous study) suggest that altruistic survival and NF-κB activation might be vital for initiating the acquisition of EGFR-TKI resistance.

Circulating exosomes suppress the induction of regulatory T cells via let-7i in multiple sclerosis

Multiple sclerosis (MS) is a T cell-mediated autoimmune disease of the central nervous system. Foxp3⁺ regulatory T (Treg) cells are reduced in frequency and dysfunctional in patients with MS, but the underlying mechanisms of this deficiency are unclear. Here, we show that induction of human IFN-γ⁻IL-17A⁻Foxp3⁺CD4⁺ T cells is inhibited in the presence of circulating exosomes from patients with MS. The exosomal miRNA profile of patients with MS differs from that of healthy controls, and let-7i, which is markedly increased in patients with MS, suppresses induction of Treg cells by targeting insulin like growth factor 1 receptor (IGF1R) and transforming growth factor beta receptor 1 (TGFBR1). Consistently, the expression of IGF1R and TGFBR1 on circulating naive CD4⁺ T cells is reduced in patients with MS. Thus, our study shows that exosomal let-7i regulates MS pathogenesis by blocking the IGF1R/TGFBR1 pathway.

MiRNAs are small RNA molecules that can regulate gene expression. Here the authors show that expression of several exosomal miRNAs are altered in patients with multiple sclerosis, and that let-7i modulates regulatory T cell homeostasis to contribute to pathogenesis.

Comprehensive Measurement of Gene Silencing Involving Endogenous MicroRNAs in Mammalian Cells

MicroRNAs (miRNAs) are functional small noncoding RNAs that work as mediators in gene silencing and that play important roles in gene regulation. A number of miRNAs have been found and their expression profiles have been examined by means of various microarray systems and real-time polymerase chain reaction (PCR) systems. Conventional microarrays as well as real-time PCR are able to detect existing miRNAs, in which inactive miRNAs that hardly contribute to gene silencing may be also contained. Here, we describe a comprehensive miRNA bioassay system with reporter genes for the detection of active miRNAs that are present in the RNA-induced silencing complexes, and actually working as mediators in gene silencing.

A randomized, open-label, phase III trial comparing amrubicin versus docetaxel in patients with previously treated non-small-cell lung cancer

Background

Amrubicin is approved for treating non-small-cell lung cancer (NSCLC) and small-cell lung cancer. However, no direct comparisons between amrubicin and docetaxel, a standard treatment for NSCLC, have been reported.

Patients and methods

We conducted a randomized phase III trial of Japanese NSCLC patients after one or two chemotherapy regimens. Patients were randomized to amrubicin (35 mg/m2 on days 1-3 every 3 weeks) or docetaxel (60 mg/m2 on day 1 every 3 weeks). Outcomes included progression-free survival, overall survival, tumor responses, and safety.

Results

Between October 2010 and June 2012, 202 patients were enrolled across 32 institutions. Median progression-free survival (3.6 versus 3.0 months; P = 0.54) and overall survival (14.6 versus 13.5 months; P = 0.86) were comparable in the amrubicin and docetaxel groups, respectively. The overall response rate was 14.4% (14/97) and 19.6% (19/97) in the amrubicin and docetaxel groups, respectively (P = 0.45). The disease control rate was 55.7% in both groups. Adverse events occurred in all patients, and included grade ≥3 neutropenia occurred in 82.7% and 78.8% of patients in the amrubicin and docetaxel groups, respectively, grade ≥3 leukopenia occurred in 63.3% and 70.7%, and grade ≥3 febrile neutropenia occurred in 13.3% and 18.2% of patients in the amrubicin and docetaxel groups, respectively. Of eight cardiac-related events in the amrubicin group, three were considered related to amrubicin and resolved without treatment discontinuation.

Conclusions

This was the first phase III study to compare amrubicin and docetaxel in patients with pretreated NSCLC. Amrubicin did not significantly improve the primary endpoint of PFS compared with docetaxel.

Clinical trial registration

NCT01207011 (ClinicalTrials.gov).

Neighbors' death is required for surviving human adenocarcinoma PC-9 cells in an early stage of gefitinib treatment

Acquired drug resistance is a major problem in chemotherapy, and understanding of the mechanism, by which naïve cells defend themselves from drugs when the cells exposed to the drugs for the first time, may provide a solution of the problem. Gefitinib is an epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor, and used as an anticancer drug; however, gefitinib treatment may sometimes lead cancer cells gradually into a gefitinib-tolerance. Here we describe that human adenocarcinoma PC-9 cells even under the presence of gefitinib were able to survive by activating another signaling pathway involving fibroblast growth factor receptor (FGFR) and its signaling molecule, FGF2; and further suggest that the FGF2 for initiating the pathway might be supplied from neighboring cells which were killed by gefitinib, i.e., the survival might be founded on neighbors' sacrifice in an early stage of gefitinib treatment. Our findings suggested that whether cells had a chance to encounter to survival factors such as FGF2 soon after gefitinib treatment might be an important crossroads for the cells for survival and for gaining a gefitinib tolerance.

Intraventricular Hemorrhage after Carotid Stenting

Purpose:

To report an important complication related to carotid stenting.

Methods and Results:

A 71-year-old man with symptomatic subtotal occlusion of the left internal carotid artery had a 30-mm lesion treated percutaneously with implantation of 2 stents. Although the procedure was completed satisfactorily, left intraventricular hemorrhage occurred 4 hours later, possibly related to hyperperfusion injury. The patient expired 30 days after the stent procedure. Preoperative single-photon emission computed tomography revealed severely reduced vasoreactivity in the affected territory after acetazolamide challenge.

Conclusions:

The risk of hyperperfusion injury must be considered and minimized in patients with significant restriction of regional vasoreactivity. We recommend that cerebral hemodynamic status be determined prior to carotid stenting.

Carotid and Vertebral Stenting: Preliminary Report

We report our initial experience of carotid and vertebral stenting. Three haemodynamically significant extra-cranial lesions (% diameter stenosis >70) in 3 clinically symptomatic patients were treated by stenting between March 1996 and September 1996.

Two lesions of the internal carotid arteries were ostial and in one case a subtotal stenosis and ostial lesion of the vertebral artery were observed.

All lesions looked more widely and smoothly dilated by stenting than by ordinary standard balloon angioplasty.

Follow-up Study after Percutaneous Transluminal Cerebral Angioplasty

The purpose of this study was to assess the safety and efficacy of percutaneous transluminal cerebral balloon angioplasty (PTCBA) of extra- and intra-cranial arteries by investigating procedural outcome. Eighty haemodynamically significant extra- and intra-cranial lesions (% diameter stenosis >70) in 74 clinically symptomatic patients were treated by elective and initial PTCBA between March 1991 and February 1996 and followed thereafter.

Death, stroke including transient ischemia, surgery, or repeated angioplasty of restenosis or new lesions were regarded as cerebral events after the initial PTCBA. Crescendo ischaemic symptoms disappeared completely after clinically successful dilatation. The clinical success rate was 81% (65/80). Angiographic restenosis rate at 3 months was 22% (14/65).

By life-table method, the death/stroke risk was 16% and death/stroke/surgery/repeated PTCBA risk was 49 % at 2 years following PTCBA, respectively.

In conclusion, PTCBA successfully, decreased recurrent neurological symptoms and produced a favourable short-term outcome, whereas restenosis limited long-term benefit.

Glucocorticoid affects dendritic transport of BDNF-containing vesicles

Brain-derived neurotrophic factor (BDNF) is essential for neuronal survival, differentiation, and functions in the central nervous system (CNS). Because BDNF protein is sorted into secretory vesicles at the trans-Golgi network in the cell body after translation, transport of BDNF-containing vesicles to the secretion sites is an important process for its function. Here we examined the effect of dexamethasone (DEX), a synthetic glucocorticoid, on BDNF-containing vesicle transport and found that DEX decreased the proportion of stationary vesicles and increased velocity of the microtubule-based vesicle transport in dendrites of cortical neurons. Furthermore, DEX increased huntingtin (Htt) protein levels via glucocorticoid receptor (GR) activation, and reduction in the amount of Htt by a specific shRNA reversed the action of DEX on BDNF vesicle transport. Given that Htt protein is a positive regulator for the microtubule-dependent vesicular transport in neurons, our data suggest that glucocorticoid stimulates BDNF vesicle transport through upregulation of Htt protein levels.

Normalization of Overexpressed α-Synuclein Causing Parkinson's Disease By a Moderate Gene Silencing With RNA Interference

The α-synuclein (SNCA) gene is a responsible gene for Parkinson's disease (PD); and not only nucleotide variations but also overexpression of SNCA appears to be involved in the pathogenesis of PD. A specific inhibition against mutant SNCA genes carrying nucleotide variations may be feasible by a specific silencing such as an allele-specific RNA interference (RNAi); however, there is no method for restoring the SNCA overexpression to a normal level. Here, we show that an atypical RNAi using small interfering RNAs (siRNAs) that confer a moderate level of gene silencing is capable of controlling overexpressed SNCA genes to return to a normal level; named "expression-control RNAi" (ExCont-RNAi). ExCont-RNAi exhibited little or no significant off-target effects in its treated PD patient's fibroblasts that carry SNCA triplication. To further assess the therapeutic effect of ExCont-RNAi, PD-model flies that carried the human SNCA gene underwent an ExCont-RNAi treatment. The treated PD-flies demonstrated a significant improvement in their motor function. Our current findings suggested that ExCont-RNAi might be capable of becoming a novel therapeutic procedure for PD with the SNCA overexpression, and that siRNAs conferring a moderate level of gene silencing to target genes, which have been abandoned as useless siRNAs so far, might be available for controlling abnormally expressed disease-causing genes without producing adverse effects.

Gene silencing mediated by endogenous microRNAs under heat stress conditions in mammalian cells

Heat shock, sudden change in temperature, triggers various responses in cells for protecting the cells from such a severe circumstance. Here we investigated gene silencing mediated by endogenous microRNAs (miRNAs) in mammalian cells exposed to a mild hyperthermia, by means of miRNA activity assay using a luciferase reporter gene as well as miRNA expression analysis using a DNA microarray. Our findings indicated that the gene silencing activities involving miRNAs were enhanced without increasing in their expression levels under heat-stress conditions. Additionally, the gene silencing activity appeared to be independent of the cytoprotective action involving heat shock proteins that are immediately activated in heat-shocked cells and that function as molecular chaperons for restoring heat-denatured proteins to normal proteins. Our current findings suggested the possibility that gene silencing involving endogenous miRNAs might play a subsidiary role in heat-shocked cells for an aggressive inhibition of the expression of heat-denatured proteins.

Identification of preferentially reactivated genes during early G1 phase using nascent mRNA as an index of transcriptional activity

During mammalian mitosis, transcription is silenced due to dissociation of transcription factors from DNA and chromosome condensation. At the end of mitosis, transcription is reactivated through chromosome relaxation and reloading of these factors to the DNA. Early G1 genes, which are preferentially reactivated during M/G1 transition, are important for maintenance of cellular function and are known to be strictly regulated. As only few early G1 genes have been identified to date, screening for early G1 genes by genome-wide analysis using nascent mRNA could contribute to the elucidation of the regulatory mechanisms during early G1. Here, we performed a detailed expression analysis for the M/G1 transition of mammalian cells by microarray analysis of nascent mRNA, and identified 298 early G1 genes. Analysis of these genes provides two important insights. Firstly, certain motifs are enriched in the upstream sequences of early G1 genes; from this we could predict candidate cognate transcription factors, including Sp1, which is recruited to the DNA in the early G1 phase. Secondly, we discovered that neighboring genes of early G1 genes were also frequently up-regulated in the G1 phase. Information about these numerous newly identified early G1 genes will likely contribute to an understanding of the regulatory mechanisms of the early G1 genes.

p53 status and prognosis in stage I-IIIa non-small cell lung cancer

To investigate the role of p53 abnormalities in predicting the survival of patients with non-small cell lung cancer (NSCLC), polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and immunohistochemical analyses were performed on 74 and 67 tumor samples, respectively, from patients with pathological stage I-IIIa NSCLC. An abnormally migrating SSCP band was observed in 21 of 74 (28%) tumor specimens. DNA sequence analysis revealed 23 intragenic mutations including 3 small deletions and 20 point mutations. Immunohistochemical analysis using the DO-7 monoclonal antibody showed abnormal expression of p53 in 27 of 67 (40%) patients. The concordance rate between immunohistochemical and PCRSSCP analyses was 73% (49/67) in this study. Univariate and multivariate analyses demonstrated that abnormal expression of p53 may be associated with prolonged survival (p=0.0997 and 0.0099, respectively). In contrast, no relationship was observed between p53 mutation and overall survival (0.6968). These results suggest that p53 status and the survival outcome changes between immunohistochemical and mutational analyses in stage I-IIIa NSCLC.

Induction chemotherapy followed by gefitinib and concurrent thoracic radiotherapy for unresectable locally advanced adenocarcinoma of the lung: a multicenter feasibility study (JCOG 0402)

BACKGROUND

We conducted a feasibility study of induction chemotherapy followed by gefitinib and thoracic radiotherapy (TRT) for unresectable locally advanced adenocarcinoma of the lung.

PATIENTS AND METHODS

Patients received induction chemotherapy with cisplatin (80 mg/m(2), days 1 and 22) and vinorelbine (25 mg/m(2), days 1, 8, 22, and 29) followed by gefitinib (250 mg daily, beginning on day 43, for 1 year) and TRT (60 Gy/30 fractions, days 57-98). The primary end point was feasibility, which was defined as the proportion of patients who completed 60 Gy of TRT and received >75% of the planned dose of gefitinib without developing grade 2 or worse pneumonitis.

RESULTS

Of the 38 enrolled patients, 23 patients [60.5% ; 80% confidence interval (CI) 48.8-71.3] completed treatment without experiencing grade 2 or worse pneumonitis. During the chemoradiation phase, grade 3-4 alanine aminotransferase elevations were observed in 37.1% of the patients. The overall response rate was 73.0% . The median survival time was 28.5 months (95% CI 22.5-38.2), and the 2-year survival rate was 65.4% .

CONCLUSIONS

Although the results did not meet our criterion for feasibility, the toxicity was acceptable. This treatment warrants further evaluation among patients with locally advanced non-small-cell lung cancer harboring epidermal growth factor receptor mutations.

Identification of thymidylate synthase as a potential therapeutic target for lung cancer

Background:

Thymidylate synthase (TS), a key enzyme in the de novo synthesis of thymidine, is an important chemotherapeutic target for malignant tumours including lung cancer. Although inhibition of TS has an antiproliferative effect in cancer cells, the precise mechanism of this effect has remained unclear.

Methods:

We examined the effects of TS inhibition with an RNA interference-based approach. The effect of TS depletion on the growth of lung cancer cells was examined using colorimetric assay and flow cytometry.

Results:

Measurement of the enzymatic activity of TS in 30 human lung cancer cell lines revealed that such activity differs among tumour histotypes. Almost complete elimination of TS activity by RNA interference resulted in inhibition of cell proliferation in all tested cell lines, suggestive of a pivotal role for TS in cell proliferation independent of the original level of enzyme activity. The antiproliferative effect of TS depletion was accompanied by arrest of cells in S phase of the cell cycle and the induction of caspase-dependent apoptosis as well as by changes in the expression levels of cyclin E and c-Myc. Moreover, TS depletion induced downregulation of the antiapoptotic protein X-linked inhibitor of apoptosis (XIAP), and it seemed to activate the mitochondrial pathway of apoptosis.

Conclusion:

Our data provide insight into the biological relevance of TS as well as a basis for clinical development of TS-targeted therapy for lung cancer.

Marked anti-tumour activity of the combination of YM155, a novel survivin suppressant, and platinum-based drugs

BACKGROUND

Survivin, a member of the inhibitor of apoptosis protein family, is an attractive target for cancer therapy. We have now investigated the effects of the combination of YM155, a novel small-molecule inhibitor of survivin expression, and platinum compounds (cisplatin and carboplatin) on human non-small cell lung cancer (NSCLC) cell lines.

METHODS

The anti-cancer efficacy of YM155 in combination with platinum compounds was evaluated on the basis of cell death and progression of tumour xenografts. Platinum compound-induced DNA damage was evaluated by immunofluorescence analysis of histone gamma-H2AX.

RESULTS

Immunofluorescence analysis of histone gamma-H2AX showed that YM155 delayed the repair of double-strand breaks induced in nuclear DNA by platinum compounds. The combination of YM155 and platinum compounds also induced synergistic increases both in the number of apoptotic cells and in the activity of caspase-3. Finally, combination therapy with YM155 and platinum compounds delayed the growth of NSCLC tumour xenografts in nude mice to an extent greater than that apparent with either treatment modality alone.

CONCLUSION

These results suggest that YM155 sensitises tumour cells to platinum compounds both in vitro and in vivo, and that this effect is likely attributable to the inhibition of DNA repair and consequent enhancement of apoptosis.