Configuration of two cysteine residues in a ring within a stapled Bim peptide affects the secondary structure and apoptotic activity.

Many reports have shown that stabilization of secondary structure by stapling functional peptides enhances the intracellular bioactivity. However, no report has discussed the correlation between stabilization and biological activity based on the configuration of amino acid residues used as anchors for stapling. To clarify this, we investigated the helix content and apoptotic efficiency of an apoptosis-inducing peptide, Bim, and four stapled Bim peptides containing stapling-related Cys residues introduced with different configurations within the sequence. The results demonstrated that the configuration of Cys residues in stapled Bim peptides affected the secondary structure and intracellular activity of the peptides, and furthermore, there was a correlation between these latter two variables.

In Vitro Study of Tumor-Homing Peptide-Modified Magnetic Nanoparticles for Magnetic Hyperthermia.

Cancer cells have higher heat sensitivity compared to normal cells; therefore, hyperthermia is a promising approach for cancer therapy because of its ability to selectively kill cancer cells by heating them. However, the specific and rapid heating of tumor tissues remains challenging. This study investigated the potential of magnetic nanoparticles (MNPs) modified with tumor-homing peptides (THPs), specifically PL1 and PL3, for tumor-specific magnetic hyperthermia therapy. The synthesis of THP-modified MNPs involved the attachment of PL1 and PL3 peptides to the surface of the MNPs, which facilitated enhanced tumor cell binding and internalization. Cell specificity studies revealed an increased uptake of PL1- and PL3-MNPs by tumor cells compared to unmodified MNPs, indicating their potential for targeted delivery. In vitro hyperthermia experiments demonstrated the efficacy of PL3-MNPs in inducing tumor cell death when exposed to an alternating magnetic field (AMF). Even without exposure to an AMF, an additional ferroptotic pathway was suggested to be mediated by the nanoparticles. Thus, this study suggests that THP-modified MNPs, particularly PL3-MNPs, hold promise as a targeted approach for tumor-specific magnetic hyperthermia therapy.

A case report of carcinoma of the papilla of Vater associated with a hyperplasia-dysplasia-carcinoma sequence by pancreaticobiliary maljunction.

BACKGROUND: Pancreaticobiliary maljunction (PBM) is a known risk factor for biliary tract cancer. However, its association with carcinoma of the papilla of Vater (PVca) remains unknown. We report a case with PVca that was thought to be caused by the hyperplasia-dysplasia-carcinoma sequence, which is considered a mechanism underlying PBM-induced biliary tract cancer. CASE PRESENTATION: A 70-year-old woman presented with white stool and had a history of cholecystectomy for the diagnosis of a non-dilated biliary tract with PBM. Esophagogastroduodenoscopy revealed a tumor in the papilla of Vater, and PVca was histologically proven by biopsy. We finally diagnosed her with PVca concurrent with non-biliary dilated PBM (cT1aN0M0, cStage IA, according to the Union for International Cancer Control, 8th edition), and subsequently performed subtotal stomach-preserving pancreaticoduodenectomy. Pathological findings of the resected specimen revealed no adenomas and dysplastic and hyperplastic mucosae in the common channel slightly upstream of the main tumor, suggesting a PBM related carcinogenic pathway with hyperplasia-dysplasia-carcinoma sequence. Immunostaining revealed positivity for CEA. CK7 positivity, CK20 negativity, and MUC2 negativity indicated that this PVca was of the pancreatobiliary type. Genetic mutations were exclusively detected in tumors and not in normal tissues, and bile ducts from formalin-fixed paraffin-embedded samples included mutated-ERBB2 (Mutant allele frequency, 81.95%). Moreover, of the cell-free deoxyribonucleic acid (cfDNA) extracted from liquid biopsy mutated-ERBB2 was considered the circulating-tumor deoxyribonucleic acid (ctDNA) of this tumor. CONCLUSIONS: Herein, we report the first case of PVca with PBM potentially caused by a "hyperplasia-dysplasia-carcinoma sequence" detected using immunostaining and next-generation sequencing. Careful follow-up is required if pancreaticobiliary reflux persists, considering the possible development of PVca.

Photo-dependent cytosolic delivery of shRNA into a single blastomere in a mouse embryo.

Single-cell-specific delivery of small RNAs, such as short hairpin RNA (shRNA) and small noncoding RNAs, allows us to elucidate the roles of specific upregulation of RNA expression and RNAi-mediated gene suppression in early embryo development. The photoinduced cytosolic dispersion of RNA (PCDR) method that we previously reported can introduce small RNAs into the cytosol of photoirradiated cells and enable RNA delivery into a single-cell in a spatiotemporally specific manner. However, the PCDR method has only been applied to planer cultured cells and not to embryos. This study demonstrated that the PCDR method can be utilized for photo-dependent cytosolic shRNA delivery into a single blastomere and for single blastomere-specific RNA interference in mouse embryos. Our results indicate that PCDR is a promising approach for studying the developmental process of early embryogenesis.

FRET probe for detecting two mutations in one EGFR mRNA.

Technologies for visualizing and tracking RNA are essential in molecular biology, including in disease-related fields. In this study, we propose a novel probe set (DAt-probe and T-probe) that simultaneously detects two mutations in the same RNA using fluorescence resonance energy transfer (FRET). The DAt-probe carrying the fluorophore Atto488 and the quencher Dabcyl were used to detect a cancer mutation (exon19del), and the T-probe carrying the fluorophore Tamra was used to detect drug resistance mutations (T790M) in epidermal growth factor receptor (EGFR) mRNA. These probes were designed to induce FRET when both mutations were present in the mRNA. Gel electrophoresis confirmed that the two probes could efficiently bind to the mutant mRNA. We measured the FRET ratios using wild-type and double-mutant RNAs and found a significant difference between them. Even in living cells, the FRET probe could visualize mutant RNA. As a result, we conclude that this probe set provides a method for detecting two mutations in the single EGFR mRNA via FRET.

Tumor-Informed Approach Improved ctDNA Detection Rate in Resected Pancreatic Cancer.

Pancreatic cancer is one of the cancers with very poor prognosis; there is an urgent need to identify novel biomarkers to improve its clinical outcomes. Circulating tumor DNA (ctDNA) from liquid biopsy has arisen as a promising biomarker for cancer detection and surveillance. However, it is known that the ctDNA detection rate in resected pancreatic cancer is low compared with other types of cancer. In this study, we collected paired tumor and plasma samples from 145 pancreatic cancer patients. Plasma samples were collected from 71 patients of treatment-naïve status and from 74 patients after neoadjuvant therapy (NAT). Genomic profiling of tumor DNA and plasma samples was conducted using targeted next-generation sequencing (NGS). Somatic mutations were detected in 85% (123/145) of tumors. ctDNA was detected in 39% (28/71) and 31% (23/74) of treatment-naïve and after-NAT groups, respectively, without referring to the information of tumor profiles. With a tumor-informed approach (TIA), ctDNA detection rate improved to 56% (40/71) and 36% (27/74) in treatment-naïve and after-NAT groups, respectively, with the detection rate significantly improved (p = 0.0165) among the treatment-naïve group compared to the after-NAT group. Cases who had detectable plasma ctDNA concordant to the corresponding tumor showed significantly shorter recurrence-free survival (RFS) (p = 0.0010). We demonstrated that TIA improves ctDNA detection rate in pancreatic cancer, and that ctDNA could be a potential prognostic biomarker for recurrence risk prediction.

Ultrasound-dependent RNAi using TatU1A-rose bengal conjugate.

Tat-U1A-rose bengal conjugate (TatU1A-RB) was prepared as an ultrasound-sensitive RNA carrier molecule. This molecule consists of Tat cell-penetrating peptide, U1A RNA-binding protein, and rose bengal as a sonosensitizer. We demonstrated that TatU1A-RB delivered RNA via the endocytosis pathway, which was followed by ultrasound-dependent endosomal escape and cytosolic dispersion of the RNA. A short hairpin RNA (shRNA) delivered by TatU1A-RB mediated RNA interference (RNAi) ultrasound-dependently. Even by ultrasound irradiation through blood cells, RNAi could be induced with TatU1A-RB and the shRNA. This ultrasound-dependent cytosolic RNA delivery method will serve as the basis for a new approach to nucleic acid therapeutics.

Fluorophore-PNA-Quencher/Quencher-DNA probe for miRNA detection.

Micro RNAs (miRNAs) are involved in a variety of biological functions and are attracting attention as diagnostic and prognostic markers for various diseases. Highly sensitive RNA detection methods are required to determine miRNA expression levels and intracellular localization. In this study, we designed new double-stranded peptide nucleic acid (PNA)/DNA probes consisting of a fluorophore-PNA-quencher (fPq) and a quencher-DNA (qD) for miR-221 detection. We optimized the fPq structure, PNA-DNA hybrid length, and hybrid position. The resultant fPq-2/qD-6b probe was a 6-bp hybrid probe with a 10-base fPq and a 6-base qD. The signal-to-background ratios of the probes showed that fPq-2/qD-6b had a higher target sensitivity than fPq (PNA beacon)-type and fP/qD-type probes. The results of the detection limit and target specificity indicate that the fPq/qD probe is promising for RNA detection in both cells and cell extracts as well as for miRNA diagnosis.

Healing of iatrogenic double-barrel left main coronary artery dissection extending to the left anterior descending artery.

Iatrogenic left main coronary artery (LMCA) dissection is a complication inadvertently caused by the interventional cardiologist and can have significant consequences. A 38-year-old man presented to hospital with non-ST-elevation myocardial infarction. Coronary angiography (CAG) revealed an obstructed proximal left circumflex artery (LCx) that was successfully treated with revascularization using a drug-eluting stent (DES). However, CAG after recanalization of the LCx demonstrated a spiral dissection of the left coronary artery from the mid-LMCA to the left anterior descending (LAD) artery and LCx. The dissection was classified as National Heart, Lung and Blood Institute type D in LAD and type F in LCx. Immediate exclusion stenting of the dissection flap by another DES and thrombolysis in myocardial infarction 3 flow were achieved in the LAD and LCx. The patient achieved hemodynamic stability with improvement in symptoms, despite residual dissection in the LAD. We, therefore, preferred careful observation over revascularization. The false lumen remained visible with a double-barrel appearance in the LAD on 6-month follow-up CAG, which disappeared at the 2-year follow-up. We report a rare case of a large double-barrel dissection that spontaneously occluded over time without any aggressive interventions. .

Renal Dysfunction as a Predictor of Slow-Flow/No-Reflow Phenomenon and Impaired ST Segment Resolution After Percutaneous Coronary Intervention in ST-Elevation Myocardial Infarction With Initial Thrombolysis in Myocardial Infarction Grade 0.

BACKGROUND: The slow-flow/no-reflow phenomenon and impaired ST segment resolution (STR) following primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI) predict unfavorable prognosis and are characterized by obstruction of the coronary microvascular. Several predictors of slow-flow/no-reflow have been revealed, but few studies have investigated predictors of slow-flow/no-reflow and STR exclusively in acute myocardial infarction patients with initial Thrombolysis in Myocardial Infarction (TIMI) Grade 0.Methods and Results:In all, 279 STEMI patients with initial TIMI Grade 0 were enrolled in the study. Slow-flow/no-reflow was defined as TIMI Grade <3 by angiography after PCI, and impaired STR was defined as STR <50% on an electrocardiogram after PCI. Slow-flow/no-reflow was observed in 31 patients. In multivariate analysis, estimated glomerular filtration rate (eGFR; odds ratio [OR] 0.97; P=0.007), a history of cerebrovascular disease (OR 4.65, P=0.007), time to recanalization ≥4 h (OR 2.76, P=0.023), and systolic blood pressure ≤90 mmHg (OR 3.45, P=0.046) were independent predictors of slow-flow/no-reflow. Impaired STR was observed in 102 of 248 patients with TIMI Grade 3. In multivariate analysis, eGFR (OR 0.94, P<0.001) and occlusion of the left anterior descending artery (OR 4.48, P<0.001) were independent predictors of impaired STR; eGFR was the only independent predictor of both slow-flow/no-reflow and impaired STR. CONCLUSIONS: Renal dysfunction may be related to coronary microvascular dysfunction and obstruction.

Photocontrolled apoptosis induction using precursor miR-664a and an RNA carrier-conjugated with photosensitizer.

Methods to spatially induce apoptosis are useful for cancer therapy. To control the induction of apoptosis, methods using light, such as photochemical internalization (PCI), have been developed. We hypothesized that photoinduced delivery of microRNAs (miRNAs) that regulate apoptosis could spatially induce apoptosis. In this study, we identified pre-miR-664a as a novel apoptosis-inducing miRNA via mitochondrial apoptotic pathway. Further, we demonstrated the utility of photoinduced cytosolic dispersion of RNA (PCDR), which is an intracellular RNA delivery method based on PCI. Indeed, apoptosis is spatially regulated by pre-miR-664a and PCDR. In addition, we found that apoptosis induced by pre-miR-664a delivered by PCDR was more rapid than that by lipofection. These results suggest that pre-miR-664a is a nucleic acid drug candidate for cancer therapy and PCDR and pre-miR-664a-based strategies have potential therapeutic uses for diseases affecting various cell types.

Clinical implementation and current advancement of blood liquid biopsy in cancer.

Liquid biopsies have been receiving tremendous attentions as easy, rapid, and non-invasive tools for cancer diagnosis. Liquid biopsy can be performed repeatedly for disease monitoring and is expected to overcome the limitations of tissue biopsies. With the advancement of next generation sequencing technologies, it is now possible to detect minute amount of tumor-derived circulation tumor DNA (ctDNA) from blood samples. Importantly, ctDNA detection could be complementary to tissue biopsies or tumor biomarkers particularly in cases of which tumor biopsy is clinically difficult to obtain. Here, we introduce the up-to-date technologies used in cfDNA-based liquid biopsy and review the clinical utilities of ctDNA in cancer screening, detection of minimal residual diseases, selection of molecular-targeted drugs, as well as monitoring of treatment responsiveness. We also discuss the challenges and future perspectives of liquid biopsy implementation in clinical setting.

Inhibition of HSF1 and SAFB Granule Formation Enhances Apoptosis Induced by Heat Stress.

Stress resistance mechanisms include upregulation of heat shock proteins (HSPs) and formation of granules. Stress-induced granules are classified into stress granules and nuclear stress bodies (nSBs). The present study examined the involvement of nSB formation in thermal resistance. We used chemical compounds that inhibit heat shock transcription factor 1 (HSF1) and scaffold attachment factor B (SAFB) granule formation and determined their effect on granule formation and HSP expression in HeLa cells. We found that formation of HSF1 and SAFB granules was inhibited by 2,5-hexanediol. We also found that suppression of HSF1 and SAFB granule formation enhanced heat stress-induced apoptosis. In addition, the upregulation of HSP27 and HSP70 during heat stress recovery was suppressed by 2,5-hexanediol. Our results suggested that the formation of HSF1 and SAFB granules was likely to be involved in the upregulation of HSP27 and HSP70 during heat stress recovery. Thus, the formation of HSF1 and SAFB granules was involved in thermal resistance.

Effects of empagliflozin in different phases of diabetes mellitus-related cardiomyopathy: a prospective observational study.

BACKGROUND: Diabetes mellitus-related cardiomyopathy (DMCMP), defined as left ventricular (LV) dysfunction caused by hyperglycemia in the absence of coronary artery disease, leads to heart failure (HF). Previous studies have shown that treatment with sodium-glucose co-transporter 2 inhibitor (SGLT2i) reduces the risk of exacerbation of HF. The beneficial effects of SGLT2i on HF depend not only on indirect actions such as osmotic diuresis but also on direct actions on the myocardium, leading to improvements in LV function. However, it remains unclear whether SGLT2i treatment is equally effective in any phase of DMCMP. The aim of this observational study was to compare the efficacy of SGLT2i treatment on LV dysfunction between early and advanced DMCMP. METHODS: Thirty-five symptomatic non-ischemic HF patients with LV ejection fraction > 40% and type 2 diabetes mellitus (T2DM) treated with empagliflozin (EMPA group) and 20 controls treated without SGLT2i were enrolled. According to the myocardial extracellular volume fraction (ECV), a reliable marker of cardiac fibrosis quantified by cardiac magnetic resonance, the EMPA group was further divided into early DMCMP (n = 16, ECV ≤ 30%) and advanced DMCMP (n = 19, ECV > 30%) groups and followed up prospectively. Echocardiography was performed at baseline and after 12 months. LV function assessed as LV global longitudinal strain (LVGLS) and the ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity (E/e') were compared. RESULTS: ECV was strongly correlated with T2DM duration (r2 = 0.65, p < 0.001). At baseline, each group had a similar background. After 12 months, the EMPA group, especially the early DMCMP group, showed remarkable improvements in LVGLS (ΔLVGLS: 2.9 ± 3.0% (EMPA) vs. 0.6 ± 2.2% (controls), p = 0.005, and 4.6 ± 1.5% (early DMCMP) vs. 1.6 ± 3.3% (advanced DMCMP), p = 0.003) and E/e' (ΔE/e': - 1.5 ± 4.7 vs. - 0.3 ± 3.0, p = 0.253, and - 3.4 ± 5.5 vs. - 0.1 ± 3.5, p = 0.043). CONCLUSIONS: The positive effects of empagliflozin on LV dysfunction were more remarkable in early than in advanced DMCMP. Early intervention of SGLT2i for DMCMP may be preferable.

Tracheobronchial Obstruction Due to Blood Clots in Acute Pulmonary Embolism with Cardiac Arrest Managed with Extracorporeal Membrane Oxygenation.

A 66-year-old Japanese woman developed pulseless electrical activity following an acute pulmonary embolism and was treated with thrombolytic therapy. She remained hemodynamically unstable and therefore underwent extracorporeal membrane oxygenation (ECMO). While receiving treatment with ECMO, blood clots induced by endobronchial hemorrhage caused tracheobronchial airway obstruction, leading to ventilatory defect. Furthermore, her cardiac function improved, resulting in cerebral hypoxemia progression. Therefore, the blood clots were removed with a Fogarty balloon catheter and endobronchial urokinase administration, resulting in improvement in her respiratory condition. Finally, ECMO was decannulated, and the patient was discharged from our hospital without difficulties in her activities of daily living.

Painful Left Bundle Branch Block Syndrome Complicated by Iron-Overload Cardiomyopathy.

Painful left bundle branch block (LBBB) syndrome is a rare disease that presents as simultaneous chest pain and transient LBBB without myocardial ischemia. We diagnosed a 72-year-old Japanese man with painful LBBB syndrome complicated by iron-overload cardiomyopathy. Phlebotomy was initially performed to improve myocardial iron deposition and conductive disturbance. Ironically, his chest pain was fully improved by the completion of incessant LBBB and walk-through phenomenon. However, this case demonstrates a clinically significant therapeutic strategy for cardiomyopathy-induced painful LBBB syndrome. Due to the lack of treatment guidelines, individualized treatment is required for each case of painful LBBB.

Lactosome-Conjugated siRNA Nanoparticles for Photo-Enhanced Gene Silencing in Cancer Cells.

The A3B-type Lactosome comprised of poly(sarcosine)3-block-poly(l-lactic acid), a biocompatible and biodegradable polymeric nanomicelle, was reported to accumulate in tumors in vivo via the enhanced permeability and retention (EPR) effect. Recently, the cellular uptake of Lactosome particles was enhanced through the incorporation of a cell-penetrating peptide (CPP), L7EB1. However, the ability of Lactosome as a drug delivery carrier has not been established. Herein, we have developed a method to conjugate the A3B-type Lactosome with ATP-binding cassette transporter G2 (ABCG2) siRNA for inducing in vitro apoptosis in the cancer cell lines PANC-1 and NCI-H226. The L7EB1 peptide facilitates the cellular uptake efficiency of Lactosome but does not deliver siRNA into cytosol. To establish the photoinduced cytosolic dispersion of siRNA, a photosensitizer loaded L7EB1-Lactosome was prepared, and the photosensitizer 5,10,15,20-tetra-kis(pentafluorophenyl)porphyrin (TPFPP) showed superiority in photoinduced cytosolic dispersion. We exploited the combined effects of enhanced cellular uptake by L7EB1 and photoinduced endosomal escape by TPFPP to efficiently deliver ABCG2 siRNA into the cytosol for gene silencing. Moreover, the silencing of ABCG2, a protoporphyrin IX (PpIX) transporter, also mediated photoinduced cell death via 5-aminolevulinic acid (ALA)-mediated PpIX accumulated photodynamic therapy (PDT). The synergistic capability of the L7EB1/TPFPP/siRNA-Lactosome complex enabled both gene silencing and PDT.

Rate Versus Rhythm Control in Tachycardia-Induced Cardiomyopathy Patients with Persistent Atrial Flutter.

Tachycardia-induced cardiomyopathy (TIC) is a potentially reversible cardiomyopathy caused by tachyarrhythmia. For atrial flutter (AFL) -induced TIC, a rhythm control strategy, such as catheter ablation, has been recommended. However, the efficacy of rate control has remained unclear due to the difficulty of achieving control using arrhythmic medications.We prospectively assessed 47 symptomatic heart failure (HF) patients with left ventricular ejection fraction (LVEF) < 50% and suspected persistent AFL-induced TIC. Patients were divided into the rhythm control strategy (n = 22; treatment with catheter ablation or electrical cardioversion) and rate control strategy (n = 25; treatment with bisoprolol) groups. The latter was further divided into the strict rate control strategy (average heart rate < 80 bpm) and lenient rate control strategy (average heart rate < 110 bpm) subgroups. The primary outcome was left ventricular (LV) function recovery, which was defined as an increase in LVEF ≥ 20% or to a value of ≥ 55% after 6 months.In the rhythm control strategy group, more patients achieved LV function recovery after 6 months (95.2% versus 60.9%, P = 0.010). The cumulative incidence of worsening HF events was significantly higher in the rate control strategy group than in the rhythm control strategy group (hazard ratio, 4.66; 95% confidence interval, 1.01-21.57). The subgroup study revealed the advantage of the strict rate control strategy for achieving LV function recovery (83.3% versus 36.4%, P = 0.036).The rate control strategy was significantly inferior to the rhythm control strategy for the LV function recovery in TIC patients with persistent AFL. Our findings suggest that the strict rate control strategy should be aimed if the rhythm control strategy cannot be performed.

Minimization of apoptosis-inducing CPP-Bim peptide.

Pro-apoptotic peptides may be promising agents for cancer therapy owing to their ability to induce apoptosis in cancer cells. TatBim, a fusion peptide of Tat cell-penetrating peptide (CPP) and the BH3 domain derived from Bim apoptosis-inducing protein, is a pro-apoptotic peptide. In this study, based on the TatBim sequence, we attempted to minimize the CPP-Bim peptide while retaining apoptosis-inducing activity. The CPP and Bim parts were systematically shortened, and the pro-apoptotic activities of the shortened peptides were examined. We obtained TatBim-N1C2 and R8Bim-N1C2 as minimized peptides with efficient apoptotic activity. These peptides may have potential applications in future biomedical studies, such as cancer therapeutics.