Pancreatic Cancer and Detection Methods

The pancreas is a vital organ with exocrine and endocrine functions. Pancreatitis is an inflammation of the pancreas caused by alcohol consumption and gallstones. This condition can heighten the risk of pancreatic cancer (PC), a challenging disease with a high mortality rate. Genetic and epigenetic factors contribute significantly to PC development, along with other risk factors. Early detection is crucial for improving PC outcomes. Diagnostic methods, including imagining modalities and tissue biopsy, aid in the detection and analysis of PC. In contrast, liquid biopsy (LB) shows promise in early tumor detection by assessing biomarkers in bodily fluids. Understanding the function of the pancreas, associated diseases, risk factors, and available diagnostic methods is essential for effective management and early PC detection. The current clinical examination of PC is challenging due to its asymptomatic early stages and limitations of highly precise diagnostics. Screening is recommended for high-risk populations and individuals with potential benign tumors. Among various PC screening methods, the N-NOSE plus pancreas test stands out with its high AUC of 0.865. Compared to other commercial products, the N-NOSE plus pancreas test offers a cost-effective solution for early detection. However, additional diagnostic tests are required for confirmation. Further research, validation, and the development of non-invasive screening methods and standardized scoring systems are crucial to enhance PC detection and improve patient outcomes. This review outlines the context of pancreatic cancer and the challenges for early detection.

Clinical Possibility of Caenorhabditis elegans as a Novel Evaluation Tool for Esophageal Cancer Patients Receiving Chemotherapy: A Prospective Study

BACKGROUND

The nematode Caenorhabditis elegans (C. elegans) possesses a sophisticated sense of smell and is used for a novel cancer screening test that utilizes the chemotaxis index. We designed a single-institution, prospective study to confirm the ability of Nematode Nose (N-NOSE) to determine preoperative chemotherapy's efficacy for esophageal cancer patients.

PATIENTS AND METHODS

We investigated the predictability of N-NOSE screening for the clinical effects of preoperative chemotherapy for esophageal cancer patients receiving radical surgery. The index reduction score (IRS) was calculated via the chemotaxis of C. elegans at three points: before treatment, before surgery, and after surgery, and its clinical relevance was examined.

RESULT

Thirty-nine patients with esophageal cancer were enrolled from August 2020 to December 2021, and 30 patients receiving radical surgery were examined. Complete response or partial response was achieved in 23 cases (76.7%). When the target of the treatment effect was complete response only, the prediction accuracies of the IRS calculated by area under the curve was 0.85 (95% Confidence interval: 0.62-1) in clinically achieving complete response group, and the sensitivity and specificity were 1 and 0.63, respectively.

CONCLUSION

Index reduction score using N-NOSE screening may reflect the efficacy of chemotherapy for esophageal cancer patients. A large-scale prospective study at multiple centers is desired in the future.

Primary Lymphangiosarcoma of the Urinary Bladder in a Dog

Abdominal ultrasonographical and computed tomography examinations of a 12-year-old neutered female toy poodle revealed a protruding mass, approximately 2 cm in diameter, at the apex of the bladder. The mass was firm and haemorrhagic with a homogeneously brownish-yellow cut surface. Microscopically, it was unencapsulated and located in the muscle layer with invasion of the extra-muscular layer. It was composed of spindloid to oval neoplastic cells that formed irregular clefts and diffuse sheets that dissected bundles of collagen. Immunohistochemically, the neoplastic cells were positive for vimentin and lymphatic vessel endothelial hyaluronan receptor 1 antigens, but negative for cytokeratin AE1/AE3, factor VIII-related antigen, CD31, CD34, Prox-1, S100, desmin, α-smooth muscle actin and MyoD1. Negative immunolabelling for laminin antigen supported the absence of evidence of a basal lamina on ultrastructural examination. Based on these findings, this tumour was identified as a lymphangiosarcoma. To the best of our knowledge, this case is the first report of lymphangiosarcoma arising from the bladder in a dog.

Diffuse Pulmonary Meningotheliomatosis with Sarcomatous Transformation in a Shiba Dog

A 2-year-old neutered female Shiba dog exhibited laboured breathing for 1 month. Computed tomography of the thoracic cavity revealed multiple nodules (2-5 mm diameter) in the lungs. Grossly, the lungs were firm and normal in shape. The nodules were grey-white in colour. Microscopically, the nodules were non-encapsulated and exhibited an irregular shape. They were composed of polygonal or spindle cells with indistinct cell borders arranged in sheets. The cells had large, round, hyperchromatic nuclei and abundant pale eosinophilic cytoplasm with no atypia. Intrapulmonary arterial emboli and infiltration into the bronchioles were observed. Immunohistochemically, the cells were positive for vimentin and negative for cytokeratin, glial fibrillary acidic protein and α-smooth muscle actin. Ultrastructurally, the cells displayed cytoplasmic processes, desmosomes and intermediate filaments. These findings led to a diagnosis of diffuse pulmonary meningotheliomatosis with sarcomatous transformation. To the best of our knowledge, this is the first report of diffuse pulmonary meningotheliomatosis in a dog.

Changes in Bradykinin and Prostaglandins Plasma Levels during Dextran-sulfate Low-density-lipoprotein Apheresis

The negative charges of dextran-sulfate (DS) used for low-density-lipoprotein (LDL) apheresis initiate the intrinsic coagulation pathway in which plasma kallikrein acts on the high-molecular-weight kininogen to produce large amounts of bradykinin. This study was undertaken to assess whether bradykinin generated during DS LDL apheresis has any physiologic effects in vivo. The plasma levels of bradykinin, prostaglandins and cyclic guanosine monophosphate (cGMP) were compared, when either of two anticoagulants, heparin or nafamostat mesilate (NM), was used during DS LDL apheresis. Although anticoagulative action by NM depends on the inhibition of thrombin activity, this substance also inhibits the activity of plasma kallikrein. During apheresis using heparin, the plasma levels of prostaglandin E2 (PGE2) increased significantly (5.6 ± 1.2 (mean ± SE, n=4) pg/ml before apheresis and 33.4 ± 13.2 after apheresis, p < 0.05) in association with an increase in bradykinin levels (17.9 ± 2.6 pg/ml before apheresis and 470 ± 135 after apheresis, p < 0.01). Interestingly, these changes were suppressed during apheresis using NM. There were no appreciable changes in cGMP during DS LDL apheresis with either of the anticoagulants. This finding suggests that bradykinin generated during apheresis has some pathophysiological effects via activation of the prostaglandin system. Our results support the view that in patients taking angiotensin-convertingenzyme inhibitors, the anaphylactoid reaction occurring during apheresis may be caused by an excessive rise in the bradykinin levels.

Low dose resveratrol ameliorates mitochondrial respiratory dysfunction and enhances cellular reprogramming

Mitochondrial disease is associated with a wide variety of clinical presentations, even among patients carrying heteroplasmic mitochondrial DNA (mtDNA) mutations, probably because of variations in mutant mtDNA proportions at the tissue and organ levels. Although several case reports and clinical trials have assessed the effectiveness of various types of drugs and supplements for the treatment of mitochondrial diseases, there are currently no cures for these conditions. In this study, we demonstrated for the first time that low dose resveratrol (RSV) ameliorated mitochondrial respiratory dysfunction in patient-derived fibroblasts carrying homoplasmic mtDNA mutations. Furthermore, low dose RSV also facilitated efficient cellular reprogramming of the patient-derived fibroblasts into induced pluripotent stem cells, partly due to improved cellular viability. Our results highlight the potential of RSV as a new therapeutic drug candidate for the treatment of mitochondrial diseases.

Mitochondrial respiratory dysfunction disturbs neuronal and cardiac lineage commitment of human iPSCs

Mitochondrial diseases are genetically heterogeneous and present a broad clinical spectrum among patients; in most cases, genetic determinants of mitochondrial diseases are heteroplasmic mitochondrial DNA (mtDNA) mutations. However, it is uncertain whether and how heteroplasmic mtDNA mutations affect particular cellular fate-determination processes, which are closely associated with the cell-type-specific pathophysiology of mitochondrial diseases. In this study, we established two isogenic induced pluripotent stem cell (iPSC) lines each carrying different proportions of a heteroplasmic m.3243A>G mutation from the same patient; one exhibited apparently normal and the other showed most likely impaired mitochondrial respiratory function. Low proportions of m.3243A>G exhibited no apparent molecular pathogenic influence on directed differentiation into neurons and cardiomyocytes, whereas high proportions of m.3243A>G showed both induced neuronal cell death and inhibited cardiac lineage commitment. Such neuronal and cardiac maturation defects were also confirmed using another patient-derived iPSC line carrying quite high proportion of m.3243A>G. In conclusion, mitochondrial respiratory dysfunction strongly inhibits maturation and survival of iPSC-derived neurons and cardiomyocytes; our presenting data also suggest that appropriate mitochondrial maturation actually contributes to cellular fate-determination processes during development.

Respiratory Chain Complex Disorganization Impairs Mitochondrial and Cellular Integrity: Phenotypic Variation in Cytochrome c Oxidase Deficiency

The relationships between the molecular abnormalities in mitochondrial respiratory chain complexes and their negative contributions to mitochondrial and cellular functions have been proved to be essential for better understandings in mitochondrial medicine. Herein, we established the method to identify disease phenotypic differences among patients with muscle histopathological cytochrome c oxidase (COX) deficiency, as one of the representative clinical features in mitochondrial diseases, by using patients' myoblasts that are derived from biopsied skeletal muscle tissues. We identified two obviously different severities in molecular diagnostic criteria of COX deficiency among patients: structurally stable, but functionally mild/moderate defect and severe functional defect with the disrupted COX holoenzyme structure. COX holoenzyme disorganization actually triggered several mitochondrial dysfunctions, including the decreased ATP level, the increased oxidative stress level, and the damaged membrane potential level, all of which lead to the deteriorated cellular growth, the accelerated cellular senescence, and the induced apoptotic cell death. Our cell-based in vitro diagnostic approaches would be widely applicable to understanding patient-specific pathomechanism in various types of mitochondrial diseases, including other respiratory chain complex deficiencies and other mitochondrial metabolic enzyme deficiencies.

Reactive oxygen species stimulate mitochondrial allele segregation toward homoplasmy in human cells

Use of heteroplasmic m.3243A > G primary fibroblast cells derived from a patient with the mitochondrial disease MELAS shows that ROS trigger vegetative segregation of heteroplasmy toward wild-type and mutant mitochondrial DNA homoplasmy via the formation of linear head-to-tail multimers (concatemers).

Mitochondria that contain a mixture of mutant and wild-type mitochondrial (mt) DNA copies are heteroplasmic. In humans, homoplasmy is restored during early oogenesis and reprogramming of somatic cells, but the mechanism of mt-allele segregation remains unknown. In budding yeast, homoplasmy is restored by head-to-tail concatemer formation in mother cells by reactive oxygen species (ROS)–induced rolling-circle replication and selective transmission of concatemers to daughter cells, but this mechanism is not obvious in higher eukaryotes. Here, using heteroplasmic m.3243A > G primary fibroblast cells derived from MELAS patients treated with hydrogen peroxide (H₂O₂), we show that an optimal ROS level promotes mt-allele segregation toward wild-type and mutant mtDNA homoplasmy. Enhanced ROS level reduced the amount of intact mtDNA replication templates but increased linear tandem multimers linked by head-to-tail unit-sized mtDNA (mtDNA concatemers). ROS-triggered mt-allele segregation correlated with mtDNA-concatemer production and enabled transmission of multiple identical mt-genome copies as a single unit. Our results support a mechanism by which mt-allele segregation toward mt-homoplasmy is mediated by concatemers.

Molecular pathomechanisms and cell-type-specific disease phenotypes of MELAS caused by mutant mitochondrial tRNA(Trp)

Introduction

Numerous pathogenic mutations responsible for mitochondrial diseases have been identified in mitochondrial DNA (mtDNA)-encoded tRNA genes. In most cases, however, the detailed molecular pathomechanisms and cellular pathophysiology of these mtDNA mutations —how such genetic defects determine the variation and the severity of clinical symptoms in affected individuals— remain unclear. To investigate the molecular pathomechanisms and to realize in vitro recapitulation of mitochondrial diseases, intracellular mutant mtDNA proportions must always be considered.

Results

We found a disease-causative mutation, m.5541C>T heteroplasmy in MT-TW gene, in a patient exhibiting mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) with multiple organ involvement. We identified the intrinsic molecular pathomechanisms of m.5541C>T. This mutation firstly disturbed the translation machinery of mitochondrial tRNA^Trp and induced mitochondrial respiratory dysfunction, followed by severely injured mitochondrial homeostasis. We also demonstrated cell-type-specific disease phenotypes using patient-derived induced pluripotent stem cells (iPSCs) carrying ~100 % mutant m.5541C>T. Significant loss of terminally differentiated iPSC-derived neurons, but not their stem/progenitor cells, was detected most likely due to serious mitochondrial dysfunction triggered by m.5541C>T; in contrast, m.5541C>T did not apparently affect skeletal muscle development.

Conclusions

Our iPSC-based disease models would be widely available for understanding the "definite" genotype-phenotype relationship of affected tissues and organs in various mitochondrial diseases caused by heteroplasmic mtDNA mutations, as well as for further drug discovery applications.

Electronic supplementary material

The online version of this article (doi:10.1186/s40478-015-0227-x) contains supplementary material, which is available to authorized users.

Mitochondrial respiratory dysfunction caused by a heteroplasmic mitochondrial DNA mutation blocks cellular reprogramming

Mitochondrial dysfunction caused by pathogenic mutations in mitochondrial tRNA genes emerges only when mutant mitochondrial DNA (mtDNA) proportions exceed intrinsic pathogenic thresholds; however, little is known about the actual proportions of mutant mtDNA that can affect particular cellular lineage-determining processes. Here, we mainly focused on the effects of mitochondrial respiratory dysfunction caused by m.3243A>G heteroplasmy in MT-TL1 gene on cellular reprogramming. We found that generation of induced pluripotent stem cells (iPSCs) was drastically depressed only by high proportions of mutant mtDNA (≥ 90% m.3243A>G), and these proportions were strongly associated with the degree of induced mitochondrial respiratory dysfunction. Nevertheless, all established iPSCs, even those carrying ∼ 100% m.3243A>G, exhibited an embryonic stem cell-like pluripotent state. Therefore, our findings clearly demonstrate that loss of physiological integrity in mitochondria triggered by mutant mtDNA constitute a roadblock to cellular rejuvenation, but do not affect the maintenance of the pluripotent state.

Impaired respiratory function in MELAS-induced pluripotent stem cells with high heteroplasmy levels

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We modeled the mitochondrial disease MELAS by generating patient-specific iPS cells.

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MELAS-iPS cells show a wide variety of heteroplasmy levels.

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MELAS-iPS cells with high heteroplasmy levels showed impaired complex I activity.

Mitochondrial diseases are heterogeneous disorders, caused by mitochondrial dysfunction. Mitochondria are not regulated solely by nuclear genomic DNA but by mitochondrial DNA. It is difficult to develop effective therapies for mitochondrial disease because of the lack of mitochondrial disease models. Mitochondrial myopathy, encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is one of the major mitochondrial diseases. The aim of this study was to generate MELAS-specific induced pluripotent stem cells (iPSCs) and to demonstrate that MELAS-iPSCs can be models for mitochondrial disease. We successfully established iPSCs from the primary MELAS-fibroblasts carrying 77.7% of m.3243A>G heteroplasmy. MELAS-iPSC lines ranged from 3.6% to 99.4% of m.3243A>G heteroplasmy levels. The enzymatic activities of mitochondrial respiratory complexes indicated that MELAS-iPSC-derived fibroblasts with high heteroplasmy levels showed a deficiency of complex I activity but MELAS-iPSC-derived fibroblasts with low heteroplasmy levels showed normal complex I activity. Our data indicate that MELAS-iPSCs can be models for MELAS but we should carefully select MELAS-iPSCs with appropriate heteroplasmy levels and respiratory functions for mitochondrial disease modeling.

Neuroendocrine carcinoma of the mammary gland in a dog

A 10-year-old female border collie was presented with a mass (2 cm diameter) in the fifth mammary gland. The mass was located in the subcutis and the cut surface was grey-white in colour. Microscopically, the mass was composed of tumour cells arranged in nests of various sizes separated by delicate fibrovascular stroma. The tumour cells had small, round hypochromatic nuclei and abundant cytoplasm. Metastases were observed in the inguinal lymph node. Immunohistochemically, most tumour cells expressed cytokeratin (CK) 20, chromogranin A, neuron-specific enolase, synaptophysin and oestrogen receptor-β, but not low molecular weight CK (CAM5.2), p63 and insulin. Ultrastructurally, the tumour cells contained a large number of electron-dense granules corresponding to neuroendocrine granules. Based on these findings, this case was diagnosed as a neuroendocrine carcinoma of the mammary gland.

A homozygous mutation of C12orf65 causes spastic paraplegia with optic atrophy and neuropathy (SPG55)

BACKGROUND

Autosomal recessive hereditary spastic paraplegias (AR-HSP) constitute a heterogeneous group of neurodegenerative diseases involving pyramidal tracts dysfunction. The genes responsible for many types of AR-HSPs remain unknown. We attempted to identify the gene responsible for AR-HSP with optic atrophy and neuropathy.

METHODS

The present study involved two patients in a consanguineous Japanese family. Neurologic examination and DNA analysis were performed for both patients, and a skin biopsy for one. We performed genome-wide linkage analysis involving single nucleotide polymorphism arrays, copy-number variation analysis, and exome sequencing. To clarify the mitochondrial functional alteration resulting from the identified mutation, we performed immunoblot analysis, mitochondrial protein synthesis assaying, blue native polyacrylamide gel electrophoresis (BN-PAGE) analysis, and respiratory enzyme activity assaying of cultured fibroblasts of the patient and a control.

RESULTS

We identified a homozygous nonsense mutation (c.394C>T, p.R132X) in C12orf65 in the two patients in this family. This C12orf65 mutation was not found in 74 Japanese AR-HSP index patients without any mutations in previously known HSP genes. This mutation resulted in marked reduction of mitochondrial protein synthesis, followed by functional and structural defects in respiratory complexes I and IV.

CONCLUSIONS

This novel nonsense mutation in C12orf65 could cause AR-HSP with optic atrophy and neuropathy, resulting in a premature stop codon. The truncated C12orf65 protein must lead to a defect in mitochondrial protein synthesis and a reduction in the respiratory complex enzyme activity. Thus, dysfunction of mitochondrial translation could be one of the pathogenic mechanisms underlying HSPs.

CRIF1 is essential for the synthesis and insertion of oxidative phosphorylation polypeptides in the mammalian mitochondrial membrane

Although substantial progress has been made in understanding the mechanisms underlying the expression of mtDNA-encoded polypeptides, the regulatory factors involved in mitoribosome-mediated synthesis and simultaneous insertion of mitochondrial oxidative phosphorylation (OXPHOS) polypeptides into the inner membrane of mitochondria are still unclear. In the present study, disruption of the mouse Crif1 gene, which encodes a mitochondrial protein, resulted in a profound deficiency in OXPHOS caused by the disappearance of OXPHOS subunits and complexes in vivo. CRIF1 was associated with large mitoribosomal subunits that were located close to the polypeptide exit tunnel, and the elimination of CRIF1 led to both aberrant synthesis and defective insertion of mtDNA-encoded nascent OXPHOS polypeptides into the inner membrane. CRIF1 interacted with nascent OXPHOS polypeptides and molecular chaperones, e.g., Tid1. Taken together, these results suggest that CRIF1 plays a critical role in the integration of OXPHOS polypeptides into the mitochondrial membrane in mammals.

A multifunctional envelope-type nanodevice for use in nanomedicine: concept and applications

In the 21st century, drug development has shifted toward larger molecules such as proteins and nucleic acids, which require the use of new chemical strategies. In this process, the drug delivery system plays a central role and intracellular targeting using nanotechnology has become a key technology for the development of successful new medicines. We have developed a new delivery system, a multifunctional envelope-type nanodevice (MEND) based on "Programmed Packaging." In this new concept of packaging, multifunctional nanodevices are integrated into a nanocarrier system according to a program designed to overcome all barriers during the course of biodistribution and intracellular trafficking. In this Account, we introduce our method for delivering nucleic acids or proteins to intracellular sites of action such as the cytosol, nucleus, and mitochondria and for targeting selective tissues in vivo via systemic administration of the nanodevices. First, we introduce an octaarginine-modified MEND (R8-MEND) as an efficient intracellular delivery system, designed especially for vaccinations and transgene expression. Many types of cells can internalize the R8-MEND, mainly by inducing macropinocytosis, and the MEND escapes from macropinosomes via membrane fusion, which leads to efficient antigen presentation via the major histocompatibility complex I pathway in antigen-presenting cells. In addition, the transfection activities of the R8-MEND in dividing cells, such as HeLa or A549 cells, are as high as those for adenovirus. However, because the R8-MEND cannot induce sufficient transgene activity in primary cultured dendritic cells, which are critical regulators of the immune response, we converted the R8-MEND into a tetralamellar MEND (T-MEND). The T-MEND uses a new packaging method and delivers condensed pDNA into the nucleus via fusion between the envelopes and the nuclear membrane. To achieve efficient transfection activity, we also optimized the decondensation of nucleic acids within the nucleus. To optimize mitochondrial drug delivery, we introduced the MITOPorter. Many types of materials can be packaged into this liposome-based nanocarrier and then delivered to mitochondria via membrane fusion mechanisms. Finally, we describe an integrated strategy for in vivo tumor delivery and optimization of intracellular trafficking. Successful tumor delivery typically requires coating the surfaces of nanoparticles with PEG, but PEG can also limit uptake by the reticuloendothelial system and reduce the efficiency of intracellular trafficking. Here we integrate the optimum biodistribution and intracellular trafficking of the MEND with an innovative strategy such as enzymatically cleavable PEG and a short membrane peptide, GALA. Some of these strategies will soon be tested in the clinic.

Profiles of blood biomarkers in alternating hemiplegia of childhood--increased MMP-9 and decreased substance P indicates its pathophysiology

Alternating hemiplegia of childhood (AHC) is a rare disorder characterized by repeated plegic attacks, movement disorders, autonomic phenomena, and developmental delay. To obtain insights into the pathophysiology of AHC, we determined the concentrations of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of MMP-1 (TIMP-1), calcitonin gene-related peptide (CGRP), and substance P (SP) in the serum/plasma of AHC patients (n=6) and control subjects (n=11) by performing enzyme-linked immunosorbent assay (ELISA). Decreased levels of serum SP (382±161 pg/ml), increased levels of plasma MMP-9 (111.0±99.3 ng/mL) and increased MMP-9/TIMP-1 ratio (0.65±0.44) were revealed, compared to those in control subjects (SP: 620±223 pg/mL, p<0.05; MMP-9: 33.5±20.3 ng/mL, p<0.05; MMP-9/TIMP-1 ratio 0.21±0.09, p<0.005). Serum CGRP levels in AHC patients (32.6±14.4 pg/mL) were comparable to those in control subjects (37.0±17.0 pg/mL). Increased MMP-9 levels may be linked to the vascular insult and is common in migraineurs. However, because AHC patients showed different changes in SP and CGRP levels compared to those shown by migraineurs, these results suggest that AHC has a pathomechanism different from the hypothesis of trigeminovascular theory. Decreased SP may represent the autonomic dysfunction in AHC, for which an etiology with progressive neuronal damage can be hypothesized.

Muscle choline kinase beta defect causes mitochondrial dysfunction and increased mitophagy

Choline kinase is the first step enzyme for phosphatidylcholine (PC) de novo biosynthesis. Loss of choline kinase activity in muscle causes rostrocaudal muscular dystrophy (rmd) in mouse and congenital muscular dystrophy in human, characterized by distinct mitochondrial morphological abnormalities. We performed biochemical and pathological analyses on skeletal muscle mitochondria from rmd mice. No mitochondria were found in the center of muscle fibers, while those located at the periphery of the fibers were significantly enlarged. Muscle mitochondria in rmd mice exhibited significantly decreased PC levels, impaired respiratory chain enzyme activities, decreased mitochondrial ATP synthesis, decreased coenzyme Q and increased superoxide production. Electron microscopy showed the selective autophagic elimination of mitochondria in rmd muscle. Molecular markers of mitophagy, including Parkin, PINK1, LC3, polyubiquitin and p62, were localized to mitochondria of rmd muscle. Quantitative analysis shows that the number of mitochondria in muscle fibers and mitochondrial DNA copy number were decreased. We demonstrated that the genetic defect in choline kinase in muscle results in mitochondrial dysfunction and subsequent mitochondrial loss through enhanced activation of mitophagy. These findings provide a first evidence for a pathomechanistic link between de novo PC biosynthesis and mitochondrial abnormality.

A new phenotype of mitochondrial disease characterized by familial late-onset predominant axial myopathy and encephalopathy

Axial myopathy is a rare neuromuscular disease that is characterized by paraspinal muscle atrophy and abnormal posture, most notably camptocormia (also known as bent spine). The genetic cause of familial axial myopathy is unknown. Described here are the clinical features and cause of late-onset predominant axial myopathy and encephalopathy. A 73-year-old woman presented with a 10-year history of severe paraspinal muscle atrophy and cerebellar ataxia. Her 84-year-old sister also developed late-onset paraspinal muscle atrophy and generalized seizures with encephalopathy. Computed tomography showed severe atrophy and fatty degeneration of their paraspinal muscles. Their mother and maternal aunt also developed bent spines. The existence of many ragged-red fibers and cytochrome c oxidase-negative fibers in the biceps brachii muscle of the proband indicated a mitochondrial abnormality. No significant abnormalities were observed in the respiratory chain enzyme activities; however, the activities of complexes I and IV were relatively low compared with the activities of other complexes. Sequence analysis of the mitochondrial DNA from the muscle revealed a novel heteroplasmic mutation (m.602C>T) in the mitochondrial tRNA^Phe gene. This familial case of late-onset predominant axial myopathy and encephalopathy may represent a new clinical phenotype of a mitochondrial disease.

Reversible infantile respiratory chain deficiency: a clinical and molecular study

OBJECTIVE

To characterize the clinical features and clarify the pathogenicity of "benign cytochrome c oxidase deficiency myopathy."

METHODS

The study included 8 patients with the phenotype of this disease. Six patients underwent muscle biopsies and all the 8 underwent mitochondrial DNA analyses. To confirm the pathogenicity of the detected mitochondrial DNA mutation, we performed northern blot analysis, using muscle specimens, and blue native polyacrylamide gel electrophoresis and respiratory chain enzyme activity assay of transmitochondrial cell lines (cybrids).

RESULTS

Clinical symptoms were limited to skeletal muscle and improved spontaneously in all cases; however, 2 siblings had basal ganglia lesions. In all patients, we identified a homoplasmic m.14674T>C or m.14674T>G mitochondrial transfer RNA-glutamate mutation. Northern blot analysis revealed decreased levels of mitochondrial transfer RNA-glutamate molecules. Muscle specimens and cybrids derived from patients showed decreased activity of respiratory complexes IV, and/or I, III; however, this was normal in naive myoblasts.

INTERPRETATION

Identification of a novel m.14674T>G mutation in addition to m.14674T>C indicated the importance of this site for disease causation. Analyses of cybrids revealed the pathogenicity of m.14674T>C mutation, which resulted in defects of cytochrome c oxidase and multiple respiratory chain enzymes. Furthermore, patients with basal ganglia lesions provided new insights into this disease, in which only skeletal muscle was thought to be affected. Normal respiratory chain enzyme activities in naive myoblasts suggested the compensatory influence of nuclear factors, which may be a clue to understanding the mechanisms of spontaneous recovery and low penetrance in families carrying the mutation.

Nuclear factor-kappa B pathway and response in a phase II trial of bortezomib and docetaxel in patients with recurrent and/or metastatic head and neck squamous cell carcinoma

BACKGROUND

Our previous study has shown that nuclear factor-kappa B (NF-kappaB)-signaling pathway was associated with a higher rate of recurrence in head and neck squamous cell carcinoma (HNSCC). The combination of bortezomib, an NF-kappaB inhibitor by inhibition of proteasomes, plus docetaxel was assessed for efficacy and toxicity.

MATERIALS AND METHODS

Patients with recurrent and/or metastatic HNSCC were enrolled on a phase II bortezomib/docetaxel trial (bortezomib 1.6 mg/m(2) and docetaxel 40 mg/m(2) on days 1 and 8 of a 21-day cycle). Response was assessed using RECIST. Tissue specimens were evaluated for the presence of human papillomavirus (HPV) and expression of NF-kappaB-associated genes.

RESULTS

Twenty-one of 25 enrolled patients were assessable for response; one partial response (PR, 5%), 10 stable disease (SD, 48%) and 10 progressive disease (PD, 48%). Patients with PR/SD had significantly longer survival compared with patients with PD and the regimen was well tolerated. Only one of 20 tumors was positive for HPV. Patients with PD had higher expression of NF-kappaB and epidermal growth factor receptor-associated genes in their tumors by gene expression analysis.

CONCLUSION

Further understanding of treatment resistance and interactions between bortezomib and docetaxel may provide novel approaches in managing HNSCC.

Effect of insulin-like growth factor 1 receptor inhibitor on sensitization of head and neck cancer cells to cetuximab and methotrexate

6079

Background: Insulin-like growth factor 1 receptor (IGF1R) is highly expressed in head and neck squamous cell carcinoma (HNSCC) and IGF1R inhibitors have been shown to modulate sensitivity to selected chemotherapeutic agents and radiation. The combination effects of an IGF1R inhibitor, MK-0646, with cetuximab or cytotoxic agents that are commonly used in the treatment of recurrent and/or metastatic HNSCC were examined in cetuximab resistant and sensitive HNSCC cell lines. Methods: The cell lines, SCC1 and its cetuximab-resistant clone 1Cc8, were treated with MK-0646, cetuximab or methotrexate, and a combination of MK-0646 and each anti-cancer drug (MK-0646 was supplied by Merck & Co., Inc.). The effect of treatments on cell proliferation and anti-tumor activity was determined using MTS assay in vitro and in vivo using mouse xenografts generated from the cell lines. Overall changes in the gene and protein expressions with the treatments were determined by DNA microarrays and western blots. Results: The IGF1R inhibitor, MK-0646, showed high-sensitivity in vitro xenograft model in SCC1 as monotherapy and increased sensitivity to cetuximab in SCC1 and to methotrexate in 1Cc8 in combination. However, MK-0646 did not inhibit cell proliferation in vitro and in vivo in 1Cc8. The gene expression array and western blot analyses showed that MK-0646 decreased expression of AKT and dihydrofolate reductase (DHFR), a target of methotrexate. Increased expressions of AKT and DHFR have been shown to associate with cetuximab and methotrexate resistance as well as radiation resistance. Conclusions: The development of tolerance in response to the IGF1R inhibitor and cetuximab is common. Whereas IGF1R inhibitors may have little therapeutic impact in cetuximab resistant, the IGF1R inhibitor may modulate response to selected chemotherapeutic agents and to radiation. The IGF1R inhibitor appears to enhance cetuximab and methotrexate response, and modulates genes associated with radiation resistance thereby providing alternative regimens for recurrent and refractory HNSCC patients who have developed resistance to initial therapies.

No significant financial relationships to disclose.

Different effects of novel mtDNA G3242A and G3244A base changes adjacent to a common A3243G mutation in patients with mitochondrial disorders

Two novel mitochondrial DNA base changes were identified at both sides of the 3243A>G mutation, the most common mutation associated with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). One was a 3244G>A transition in a girl with MELAS. The other was a 3242G>A transition in a girl with a mitochondrial disorder without a MELAS phenotype. Although the two base changes were adjacent to the 3243A>G mutation, they had different effects on the clinical phenotype, muscle pathology, and respiratory chain enzyme activity. Investigations of the different effects of the 3244G>A and 3242G>A base changes may provide a better understanding of tRNA dysfunction in mitochondrial disorders.

Dynamic sealing of lung air leaks by the transplantation of tissue engineered cell sheets

Current methods including the use of various biological and synthetic sealants are ineffective in the closure of intraoperative air leaks that often occur during cardiothoracic surgeries, resulting in a decreased quality of life for patients. We present the development of a novel lung air leak sealant using tissue engineered cell sheets. In contrast to previous materials such as fibrin glue, these bioengineered cell sheets immediately and permanently seal air leaks in a dynamic fashion that allows for the extensive tissue contraction and expansion involved in respiration, without any postoperative recurrences. Additionally, we demonstrate that mesothelial cells migrate to cover the transplanted cells sheets, thereby confirming excellent biocompatibility and integration with the host tissues. Finally, we present the use of skin fibroblasts as an effective and readily available autologous cell source that can be easily applied. This study shows for the first time, the development of an immediate and permanent lung air leak sealant, suitable for future clinical applications.

Patterned biofunctional designs of thermoresponsive surfaces for spatiotemporally controlled cell adhesion, growth, and thermally induced detachment

In the present study, we report advanced patterned biofunctionalization of thermoresponsive surfaces for achievement of spatiotemporally controlled cell adhesion, growth, and thermally induced detachment. These patterned biofunctional thermoresponsive surfaces were prepared using dual surface modification techniques: electron beam-induced surface patterning of carboxyl-functional thermoresponsive polymers with appropriate metal masks and following site-selective biofunctionalization with biomolecules, the cell adhesive peptide (RGDS) and/or the cell growth factor (insulin; INS). Patterned co-immobilization of RGDS-INS onto thermoresponsive surfaces dominated site-selective cell adhesion and growth along with patterned biofunctional domains in the serum-free culture. Spatiotemporal detachment of sparsely adherent and confluent cells from these patterned biofunctional thermoresponsive surfaces were both achieved only by reducing temperature. Furthermore, RGDS-INS-patterned thermoresponsive surfaces also successfully demonstrated the selective fabrication and recovery of either contiguous monolayer or mesh-like designed monolayer tissue constructs on the identical surfaces. Thus, patterned biofunctional designs would be utilized for the creation and harvest of biomimetic-designed vascular networks having sufficient biofunctional activities in facilitated cell sheet engineering and regenerative medicine.

Bio-functionalized thermoresponsive interfaces facilitating cell adhesion and proliferation

Bio-functionalized thermoresponsive culture interfaces co-immobilized with cell adhesive peptide, RGDS, and cell growth factor, insulin (INS), are investigated to promote initial cell adhesion and cell growth for further cell sheet engineering applications. These bio-functionalized interfaces were prepared by electron beam-induced copolymerization of N-isopropylacrylamide (IPAAm) with its carboxyl-derivatized analog, 2-carboxyisopropylacrylamide (CIPAAm), and grafting onto tissue culture polystyrene dishes, followed by immobilization of RGDS and/or INS to CIPAAm carboxyls. Adhesion and proliferation of bovine carotid artery endothelial cells (ECs) were examined on the RGDS-INS co-immobilized thermoresponsive interfaces. Immobilized RGDS facilitated initial EC adhesion on the surfaces and INS modification was demonstrated to induce EC proliferation, respectively. More pronounced EC growth was indicated by co-immobilization of appropriate amount of RGDS and INS. This may be due to synergistic effect of direct co-stimulation of adhered ECs by surface-immobilized RGDS and INS molecules. ECs grown on the RGDS-INS co-immobilized thermoresponsive interfaces can also be recovered spontaneously as viable tissue monolayers by solely reducing culture temperature. RGDS-INS co-immobilized thermoresponsive interfaces strongly supported initial EC adhesion and growth than unmodified thermoresponsive surfaces even under serum-free culture. Addition of soluble growth factors to serum-free culture medium effectively induced EC proliferation to confluency. Co-immobilization of cell adhesion peptides and growth factors on thermoresponsive surfaces should be effective for rapid preparation of intact cell sheets and their utilization to regenerative medicine.

Development of a novel systemic gene delivery system for cancer therapy with a tumor-specific cleavable PEG-lipid

For successful cancer gene therapy via intravenous (i.v.) administration, it is essential to optimize the stability of carriers in the systemic circulation and the cellular association after the accumulation of the carrier in tumor tissue. However, a dilemma exists regarding the use of poly(ethylene glycol) (PEG), which is useful for conferring stability in the systemic circulation, but is undesirable for the cellular uptake and the following processes. We report the development of a PEG-peptide-lipid ternary conjugate (PEG-Peptide-DOPE conjugate (PPD)). In this strategy, the PEG is removed from the carriers via cleavage by a matrix metalloproteinase (MMP), which is specifically expressed in tumor tissues. An in vitro study revealed that the PPD-modified gene carrier (Multifunctional Envelope-type Nano Device: MEND) exhibited pDNA expression activity that was dependent on the MMP expression level in the host cells. In vivo studies further revealed that the PPD was potent in stabilizing MEND in the systemic circulation and facilitating tumor accumulation. Moreover, the i.v. administration of PPD or PEG/PPD dually-modified MEND resulted in the stimulation of pDNA expression in tumor tissue, as compared with a conventional PEG-modified MEND. Thus, MEND modified with PPD is a promising device, which has the potential to make in vivo cancer gene therapy achievable.

Tissue Engineered Epithelial Cell Sheets for the Creation of a Bioartificial Trachea

To successfully engineer a bioartificial tracheal replacement, it is believed that the regeneration of a functional epithelial lining is a key requirement. In the present study, rabbit tracheal epithelial cells were cultured on temperature-responsive culture dishes, under normal culture conditions at 37 degrees C. By simple temperature reduction to 20 degrees C, the cultured epithelial cells were noninvasively harvested as intact sheets, without the use of any proteolytic enzymes. Support Dacron grafts that had been subcutaneously implanted for 4 weeks to allow for host tissue and vessel infiltration were then opened, and the tracheal epithelial cell sheets were transplanted to the luminal surface without sutures. These fabricated constructs were then used as tracheal replacements, in a rabbit model. Four weeks after transplantation, results showed that the tracheal grafts were covered by a mature, pseudostratified columnar epithelium. In contrast, control constructs that did not receive cell sheet transplantation demonstrated only a thin, immature epithelium at the center of the replacement graft. These results therefore demonstrate that these tracheal epithelial cell sheets can create an epithelial lining on the luminal surface of a bioartificial trachea.

Influence of insulin immobilization to thermoresponsive culture surfaces on cell proliferation and thermally induced cell detachment

Temperature-responsive culture dishes immobilized with insulin have been fabricated and studied to shorten cell culture periods by facilitating more rapid cell proliferation. Cells are recovered as contiguous cell sheets simply by temperature changes. Functionalized culture dishes were prepared by previously reported electron beam grafting copolymerization of N-isopropylacrylamide (IPAAm) with its carboxylate-derivatized analog, 2-carboxyisopropylacrylamide (CIPAAm), having similar molecular structure to IPAAm but with carboxylate side chains to tissue culture polystyrene dishes. Insulin was then immobilized onto culture dishes through standard amide bond formation with CIPAAm carboxylate groups. Adhesion and proliferation of bovine carotid artery endothelial cells (ECs) were examined on these insulin-immobilized dishes. Insulin immobilization was shown to promote cell proliferation in serum-supplemented medium. Increasing the grafted CIPAAm content on the tissue culture surfaces reduces cell adhesion and proliferation, even though these surfaces contained increased amounts of immobilized insulin. This result implies that a discrete balance exists between the amount of CIPAAm-free carboxylate groups and immobilized insulin for optimum cell proliferative stimulation. Cells grown on the insulin-immobilized surfaces can be recovered as contiguous cell monolayers simply by lowering culture temperature, without need for exogenous enzyme or calcium chelator additions. In conclusion, insulin-modified thermoresponsive culture dishes may prove useful for advanced cell culture and tissue engineering applications since they facilitate cell proliferation, and cultured cells can be recovered as viable contiguous monolayers by merely reducing culture temperature.

[Extrapleural pneumonectomy for malignant pleural mesothelioma]

Standard treatment for malignant pleural mesothelioma (MPM) has not been proved yet. However, it has been recognized that extrapleural pneumonectomy (EPP) is a treatment of choice for epithelial MPM when combined with adjuvant therapies though EPP may frequently cause fetal complications. We report 5 cases of MPM with EPP, including 1 with good prognosis. Sixteen patients with MPM were admitted to our hospital between 1988 and 2003. Five patients underwent EPP, among which 4 were male and 1 female with ages from 46 to 61 years old. Histologically, 3 of them were epithelial and 2 were biphasic. Those with biphasic experienced acute respiratory failure and empyema, and died 81 days and 8 months after the surgery respectively. Among those with epithelial MPM, 2 are alive with no recurrence at 129 and 29 months after the surgery, and the other, followed by postoperative radiotherapy, died at 12 months. More cases with EPP or randomized controlled trials regarding EPP are necessary to evaluate efficacy of EPP for MPM.

Antidiabetic effect of a nitrosamine-free dephostatin analogue, methoxime-3,4-dephostatin, in db/db mice

Et-3,4-dephostatin, a protein-tyrosine phosphatase (PTPase) inhibitor, potentiates insulin-dependent signal transduction and shows an antidiabetic effect in mice. However, it contains a nitrosamine moiety that is often mutagenic and carcinogenic. Therefore, we previously designed and synthesized methoxime-3,4-dephostatin as a nitrosamine-free analogue of dephostatin. In the present paper, we studied in situ and in vivo antidiabetic effects of this PTPase inhibitor. Methoxime-3,4-dephostatin induced 2-deoxyglucose transport by mouse 3T3-L1 adipocytes and rat L6 myocytes without insulin. It also inhibited glucagon-induced glucose release from primary culture rat hepatocytes. When hepatocytes were prepared from starved rats, methoxime-3,4-dephostatin did not inhibit the release of glucose, indicating that the chemical may act on glycogenolysis. Oral administration of methoxime-3,4-dephostatin for 3-7 days inhibited the increase in the blood glucose level in type-2 diabetes model db/db mice. It also decreased food and water intakes of mice, but showed no liver or blood toxicity.

[Is the bronchoscopic criteria of early lung cancer valid?]

We studied the validity of the bronchoscopic criteria of the early lung cancer using the surgical specimen excised between 1980 and 1999. Twenty-four cases with squamous cell carcinoma of the lung of clinical stage I were located subsegmental or more proximal bronchi and trachea, and the size less than 20 mm in greatest dimension. We histopathologically investigated the endoscopic features in relation to the width of superficial extent, the depth of cancer invasion, and lymph node metastasis. Tumors of the thickened type lesions less than 20 mm in greatest dimension showed no invasion into the cartilaginous layer and no lymph node metastasis. On the other hand, in the nodular and polypoid types, invasion beyond the cartilaginous layer was observed more or less, and lymph node metastasis was observed in 1 case. These cases would not be suitable for bronchoscopic (photodynamic) therapy. In conclusion, the bronchoscopic criteria of early lung cancer is valid in the thickened type, but not in the nodular type or polypoid type.

Muscle layer- and region-dependent distributions of oxytocin receptors in the porcine myometrium

The aim of the present study was to clarify smooth muscle- and region-dependent distributions of the oxytocin receptor that mediates oxytocin-induced contraction in the nonpregnant porcine myometrium by means of mechanical and radioligand ([3H]-oxytocin) binding studies. In Krebs solution, oxytocin (0.1-300 nM) caused concentration-dependent contractions of the cornual myometrium, and the longitudinal muscle was more sensitive than the circular muscle. [Arg8]-vasopressin and [deamino-Cys1, D-Arg8]-vasopressin also contracted the myometrium, and the order of the potency was oxytocin > [Arg8]-vasopressin > [deamino-Cys(1), D-Arg(8)]-vasopressin. Treatment with a high concentration of oxytocin selectively inhibited the contraction of oxytocin and [Arg8]-vasopressin without affecting the responses of acetylcholine and high-K+. Selective cross inhibition was also observed in the presence of a high concentration of [Arg(8)]-vasopressin. The oxytocin-induced contraction was resistant to tetrodotoxin and atropine, but was reduced by verapamil or by the removal of external Ca2+, indicating that oxytocin has a direct action on smooth muscle cells and that extracellular Ca2+ plays an important role for the contraction. In Kumagai solution, oxytocin caused contraction of the cornual longitudinal muscle (-logEC50 = 8.5) but not the circular muscle. Longitudinal muscles of other regions (corpus and cervix) were also responsive to oxytocin, but the -logEC50 value differed from region to region (cornua > corpus = cervix). On the other hand, oxytocin failed to cause contraction of the corpus and cervical circular muscles. 3H-Oxytocin bound to crude membrane preparations of the myometrium in a concentration-dependent (0.084-2.7 nM) saturable manner. Scatchard analysis of equilibrium binding data revealed the presence of a single class of binding site with an apparent dissociation constant (Kd, 1.1-1.5 nM), but receptor density (Bmax) differed in the two muscle layer types (longitudinal muscle: circular muscle = 5:1) and tended to decrease from the cornua to the cervix. In conclusion, the receptor specific for oxytocin is present in the porcine myometrium and mediates the contractile responses of both oxytocin and [Arg8]-vasopressin. The distribution of the oxytocin receptors differs according to the type of muscle layer (longitudinal muscle > circular muscle) and the region of the uterus.

A study of piriform sinus fistula cases

We have experienced five cases of piriform sinus fistula for the last 10 years. It is a relatively rare disease, and partly because of poor understanding of the disease, in one case infection had repeatedly recurred without being adequately treated for over 20 years, and in most cases there was a long time lapse before the diagnosis. In another case, it was difficult to image the fistula with contrast medium and fistulectomy was performed without identifying it on imaging. We have applied various devices to those cases where imaging of fistula was difficult, and achieved complete resection of fistula and have not observed recurrences of infection after resection.