Usefulness of Ultrasonographic Detective Flow Imaging for Detecting Parathyroid Tumors: A Report of Two Cases

Parathyroid tumors (PTs) are sometimes difficult to diagnose because they are small and have low-velocity blood flow, which can be missed by current imaging modalities. PTs consist of parathyroid adenoma (PA), parathyroid cyst, and parathyroid carcinoma (PC). Detective flow imaging (DFI) is a new imaging technology that displays low-velocity blood flow. Herein, we report two cases in which DFI was useful for diagnosis of PTs. One patient had a PA and a parathyroid cyst in close proximity, and the other had a PC. To our knowledge, this is the first report to demonstrate the usefulness of DFI in the diagnosis of PTs.

Regulation of Macrophage Polarization in Allergy by Noncoding RNAs

Allergy is a type 2 immune reaction triggered by antigens known as allergens, including food and environmental substances such as peanuts, plant pollen, fungal spores, and the feces and debris of mites and insects. Macrophages are myeloid immune cells with phagocytic abilities that process exogenous and endogenous antigens. Upon activation, they can produce effector molecules such as cytokines as well as anti-inflammatory molecules. The dysregulation of macrophage function can lead to excessive type 1 inflammation as well as type 2 inflammation, which includes allergic reactions. Thus, it is important to better understand how macrophages are regulated in the pathogenesis of allergies. Emerging evidence highlights the role of noncoding RNAs (ncRNAs) in macrophage polarization, which in turn can modify the pathogenesis of various immune-mediated diseases, including allergies. This review summarizes the current knowledge regarding this topic and considers three classes of ncRNAs: microRNAs, long ncRNAs, and circular ncRNAs. Understanding the roles of these ncRNAs in macrophage polarization will provide new insights into the pathogenesis of allergies and identify potential novel therapeutic targets.

Use of Ultrasonographic Shear Wave Measurements to Diagnose Thyroid Metastasis from Breast Carcinoma

A metastatic thyroid tumor (MTT) arising from breast carcinoma (BC) is rare and sometimes difficult to diagnose. We present a case of MTT from BC; we suspected anaplastic thyroid carcinoma at initial presentation. The patient was a 58-year-old female with a hard nodule in the right anterior neck and a history of breast cancer. Computed tomography indicated tumors on both thyroid lobes, and ultrasonography (US) with shear wave measurement (SWM) showed malignant features. We performed fine needle aspiration cytology (FNAC), the results of which led us to strongly suspect MTT from BC. The surgically resected specimen was evaluated histopathologically, including by immunohistochemistry (IHC), and the diagnosis was confirmed. In addition to FNAC and IHC, SWM is useful to diagnose MTT from BC.

Retrospective single-arm cohort study of video-assisted thoracic surgery for treatment of idiopathic peripherally located simple type pulmonary arteriovenous malformation in 23 consecutive patients

BACKGROUND

Although case reports of video-assisted thoracic surgery (VATS) for pulmonary arteriovenous malformation (PAVM) have been published, studies analyzing more than 10 cases were limited. A retrospective single-arm cohort study was performed to investigate the efficacy of VATS in 23 consecutive patients with idiopathic peripherally located simple type PAVM.

METHODS

VATS was performed for wedge resection of 24 PAVMs in 23 patients, which included 4 males and 19 females with an age range of 25 to 80 years (mean: 59.6 ± 13.0). Two patients underwent simultaneous resection of lung carcinoma, one by wedge resection and another by lobectomy. Each medical record was analyzed according to the resected specimen, bleeding volume, postsurgical hospital stay length, duration of chest tube placement, and VATS time. The distance between pleural surface/fissure and PAVM was measured on CT, and the influence of this distance on identification of PAVM was investigated.

RESULTS

In all 23 patients, VATS was successfully performed, and the venous sac was included in each resected specimen. Bleeding volume was less than 10mL in all but one with 1900 mL bleeding volume due to simultaneous lobectomy for carcinoma, not wedge resection of PAVM. Postsurgical hospital stay length, duration of chest tube placement, and VATS time were 5.0 ± 1.4 days, 2.7 ± 0.7 days, and 49.3 ± 39.9 min, respectively. In 21 PAVMs with a distance of 1 mm or less, purple vessel or pleural bulge of PAVM was identified soon after insertion of a thoracoscope. In the remaining 3 PAVMs with a distance of 2.5 mm or more, additional efforts were needed for identification.

CONCLUSION

VATS was found to be a safe and effective to treatment for idiopathic peripherally located simple type PAVM. When the distance between pleural surface/fissure and PAVM was 2.5 mm or more, a plan and strategy for identification of PAVM should be prepared before VATS.

Gastrocolic fistula caused by transverse colon cancer: a case report

BACKGROUND

A gastrocolic fistula is an unusual communication between the colon and the stomach. Although colon cancer is the most common malignant cause of gastrocolic fistula in the Western world, the incidence of gastrocolic fistula due to colon cancer is 0.3% in operated cases.

CASE PRESENTATION

A 68-year-old man presented with anorexia, general malaise, weight loss, and vomiting of fecal matter. Investigations revealed that the patient had a large nonmetastatic splenic flexure tumor that was diagnosed as colon cancer and had invaded the stomach and pancreas. An upper gastrointestinal series confirmed a gastrocolic fistula. Left hemicolectomy, distal gastrectomy, distal pancreatectomy, and splenectomy were performed. Histology revealed transverse colon cancer, which was UICC stage (8th edition) pT4bN1bcM0 pStage IIIC. Adjuvant chemotherapy was not performed. There was no recurrence or metastasis one year after surgery. We reviewed 17 cases including our case of a gastrocolic fistula caused by colon cancer. Neoadjuvant chemotherapy was not given to any of the patients, and en bloc resections were conducted in all cases. Adjuvant chemotherapy was given to almost all of the patients. There was no recurrence or metastasis.

CONCLUSIONS

For gastrocolic fistula caused by advanced colon cancer, secure en bloc surgical resection was the initial treatment in all 17 reported cases including the present case, and adjuvant chemotherapy may contribute to a better prognosis.

VsN, a Reliability-index of Shear-wave Measurement in Sonoelastography, Is Useful for the Diagnosis of Thyroid Tumor Malignancy

BACKGROUND/AIM

Shear wave measurement (SWM) is a new elastography modality that quantifies the shear wave velocity (Vs) and the percentage of the net effective shear wave velocity (VsN). This study examined whether these parameters could be used to differentiate between malignant and benign thyroid tumors.

PATIENTS AND METHODS

The study of SWM enrolled 111 patients (133 nodules) who underwent thyroid surgery. Overall, 61 nodules were diagnosed as benign and 72 as malignant, of which 68 nodules were diagnosed as papillary thyroid carcinoma (PTC) and 4 as follicular thyroid carcinoma (FTC).

RESULTS

A preoperative SWM revealed that Vs was significantly higher and VsN significantly lower in the PTC compared to the benign nodules. The VsN of FTC was significantly lower than that of follicular adenoma. Multivariate analysis revealed that VsN significantly correlated with nodule malignancy.

CONCLUSION

SWM parameters, especially VsN, can potentially differentiate between benign and malignant thyroid nodules non-invasively.

Structure-based prediction of the IgE epitopes of the major dog allergen Can f 1

Allergy to dogs has become increasingly prominent worldwide. Seven dog allergens have been identified, including Canis familiaris allergen 1-7 (Can f 1-7). Although Can f 1 is a major dog allergen sensitized to 50-75% of dog-allergic subjects, its IgE epitopes have not been identified. The structural analysis of an allergen is important to identify conformational epitopes. In this study, we generated a recombinant Can f 1 protein and determined its crystal structure using X-ray crystallography. Can f 1 had a typical lipocalin fold, which is composed of an eight-stranded β-barrel and α-helix, and has high similarity to Can f 2, Can f 4, and Can f 6 in overall structure. However, the localizations of surface charges on these proteins were quite different. Based on sequence alignment and tertiary structure, we predicted five critical residues (His86, Glu98, Arg111, Glu138, and Arg152) for the IgE epitopes. The relevance of these residues to IgE reactivity was assessed by generating Can f 1 mutants with these residues substituted for alanine. Although the effects of the mutation on IgE binding depended on the sera of dog-allergic patients, H86A and R152A mutants showed reduced IgE reactivity compared with wild-type Can f 1. These results suggest that Can f 1 residues His86 and Arg152 are candidates for the IgE conformational epitope.

Microarray analysis of ductal carcinoma in situ samples obtained by puncture from surgical resection specimens

Objective

The incidence of ductal carcinoma in situ (DCIS) is increasing due to more widespread mammographic screening. DCIS, the earliest form of breast cancer, is non-invasive at the time of detection. If DCIS tissues are left undetected or untreated, it can spread to the surrounding breast tissue. Thus, surgical resection is the standard treatment. Understanding the mechanism underlying the non-invasive property of DCIS could lead to more appropriate medical treatments, including nonsurgical options.

Data description

We conducted a microarray-based genome-wide transcriptome analysis using DCIS specimens obtained by puncture from surgical specimens immediately after surgery.

Semipinacol rearrangement of a bicyclo[7.2.0]undecane framework into a bicyclo[6.3.0]undecane skeleton: a model study on the biosynthesis of seiridiasteriscane A

Seiridiasteriscane A is an asteriscane-type sesquiterpenoid bearing a trans-fused bicyclo[6.3.0]undecane skeleton. Although its biosynthesis has been proposed to involve a semipinacol rearrangement of a putative intermediary acetate bearing a bicyclo[7.2.0]undecane ring system (presumably derived from coisolated pestalotiopsin M) followed by epimerization of the resulting cis-fused seiridiasteriscane B, such a type of semipinacol rearrangement has never been reported so far. Our model study revealed that a 1-hydroxybicyclo[7.2.0]undecan-2-yl acetate underwent a smooth and stereospecific semipinacol rearrangement with the assistance of Et2AlCl to give the corresponding bicyclo[6.3.0]undecane-9-one. In addition, the resulting cis-fused 5,8-bicyclic ketone was partially epimerized to the corresponding trans-fused ketone by prolonged adsorption onto a silica gel plate. These results may support a recently proposed biosynthetic pathway of seiridiasteriscane A.

Clinical Utility of Fine Needle Aspiration Cytology for Adenoid Cystic Carcinoma of the Trachea with Thyroid Invasion: A Case Report

BACKGROUND

Adenoid cystic carcinoma of the trachea (ACCT) is a rare cancer; ACCT with thyroid invasion is particularly rare. We first suspected anaplastic thyroid carcinoma (ATC) but diagnosed ACC after performing fine needle aspiration cytology (FNAC). A tracheal origin was confirmed after operation.

CASE DESCRIPTION

We report the case of a 77-year-old female presenting to our hospital with acute inspiratory dyspnea requiring emergency tracheotomy. Physical examination revealed a right anterior neck swelling with a hard and unmovable mass. Computed tomography (CT) and ultrasonography (US) showed tumor extension to the right thyroid lobe, and between the first and third tracheal rings, which caused severe stenosis of the lumen. Next, we performed FNAC. Clinical findings were highly suspicious for ACCT with thyroid invasion. Thirty-five days after the first visit to our department, the patient underwent total laryngectomy, cervical esophagectomy, and thyroidectomy with bilateral selective neck dissections at another hospital. The tumor was located in the right posterior wall of the trachea, with extension into the right thyroid gland. Pathological examination showed an infiltrative carcinomatous proliferation with tubular and cribriform patterns. The tumor was classified as pT4N1. A definite diagnosis was made after histopathological analyis of the surgical specimen confirmed ACCT. The tumor was found to be positive for FABP7, a putative prognostic marker of ACC, and metastasized to the lungs 3 years after the surgery.

CONCLUSIONS

ACCT with thyroid invasion is an extremely rare malignant neoplasm. FNAC was useful for differentiating ACCT from other diagnoses and enabled appropriate surgical treatment.

A population-based study of outcomes in patients with surgically resected non-small cell lung cancer with anaplastic lymphoma kinase-rearranged mutations: A matched-pair study

The present study aimed to evaluate clinical outcomes in patients with surgically resected non-small cell lung cancer (NSCLC) with anaplastic lymphoma kinase (ALK)-rearranged mutations. A matched-pair analysis in completely resected ALK-rearranged NSLC patients and those with neither ALK nor epidermal growth factor receptor (EGFR) mutations diagnosed at 11 institutes was performed between April 2008 and March 2019. A total of 51 patients with surgically resected ALK-rearranged NSCLC were included. Women constituted 68.6%, and smokers 29.4%. The median age was 65 years. In matched-pair analysis, disease-free survival and overall survival did not differ between patients with ALK-rearranged mutations and those without mutations. Post-recurrence survival in patients with ALK mutations was longer than that of patients with neither ALK nor epidermal growth factor receptor mutations. ALK genetic testing should be performed, even in elderly patients with NSCLC. Favorable prognosis might be expected after appropriate treatment for patients with recurrent ALK-mutated disease.

Microarray analysis of formalin-fixed, paraffin-embedded follicular thyroid carcinoma samples from patients who developed postoperative distant metastasis

Objective

Although follicular thyroid carcinoma (FTC) generally has a good prognosis, it occasionally metastasises, leading to poor prognosis. Unfortunately, minimally invasive FTC (mi-FTC) and encapsulated angioinvasive FTC (ea-FTC) cannot be distinguished cytopathologically from thyroid follicular adenoma (FTA), a benign tumour with a good prognosis. Therefore, a molecular diagnosis to distinguish mi- or ea-FTC from FTA is needed for clinical treatment. Several transcriptomics/proteomics studies have searched for FTC biomarkers. However, the results of these studies were not consistent, which could be partly explained by inaccurate diagnosis of the specimens analysed.

Data description

We conducted a microarray-based genome-wide transcriptome analysis using formalin-fixed paraffin-embedded mi- or ea-FTC specimens from patients who developed distant metastasis up to 10 years postoperatively, which ensured the accuracy of diagnosis.

Datasets of microarray analysis to identify Gpr137b-dependent interleukin-4-responsive genes in the mouse macrophage cell line RAW264

Macrophages are classified mainly into two subtypes, M1 and M2, which exhibit distinct phenotypes, based on their microenvironment. We have recently demonstrated that Gpr137b is abundantly expressed in RAW264 macrophages, “Gpr137b is an orphan G-protein-coupled receptor associated with M2 macrophage polarization” (Islam et al., in press) [1]. Although recent studies have suggested that G-protein-coupled receptors (GPCRs) are associated with M1/M2 macrophage polarization (“G-protein-coupled bile acid receptor 1 (GPBAR1, TGR5) agonists reduce the production of proinflammatory cytokines and stabilize the alternative macrophage phenotype” (Hogenauer et al., 2014) [2], “Leukotriene B4 promotes neovascularization and macrophage recruitment in murine wet-type AMD models” (Sasaki et al., 2018) [3]), available information about GPCR-mediated macrophage polarization is still limited. This prompted us to generate Gpr137b-knockout (KO) RAW264 clones using the CRISPR/Cas9 genome editing system to elucidate the function of Gpr137b in interleukin (IL)-4-induced M2 macrophage polarization (Islam et al., in press) [1].

Here we present the datasets of a microarray analysis to identify Gpr137b-dependent IL-4-responsive genes in RAW264 cells. The raw microarray data are available in the Gene Expression Omnibus database (https://www.ncbi.nlm.nih.gov/geo/) under the accession number GSE117578, https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE117578.

Abstract 757: MiR-141-3p is upregulated in esophageal squamous cell carcinoma and targets pleckstrin homology domain leucine-rich repeat protein phosphatase-2, a negative regulator of the PI3K/AKT pathway

The phosphatidylinositol-3-kinase (PI3K)/AKT pathway is frequently activated in various human cancers and plays essential roles in their development and progression. Accumulating evidence suggests thatdysregulated expression of microRNAs (miRNAs) is closely associated with cancer progression and metastasis. Here, we focused on miRNAs that could regulate genes related to the PI3K/AKT pathway inesophageal squamous cell carcinoma (ESCC).To identify upregulated miRNAs and their possible target genes in ESCC, we performed microarraybased integrative analyses of miRNA and mRNA expression levels in three human ESCC cell lines and a normal esophageal epithelial cell line. The miRNA microarray analysis revealed that miR-31-5p, miR-141-3p, miR-200b-3p, miR-200c-3p, and miR-205-5p were expressed at higher levels in the ESCC cell linesthan the normal esophageal epithelial cell line. Bioinformatical analyses of mRNA microarray data identified several AKT/PI3K pathway-related genes as candidate targets of these miRNAs, which include tumor suppressors such as DNA-damage-inducible transcript 4 and pleckstrin homology domain leucine-rich repeat protein phosphatase-2 (PHLPP2). To validate the targets of relevant miRNAs experimentally, synthetic mimics of the miRNAs were transfected into the esophageal epithelial cell line. Here, we report that miR-141-3p suppress the expression of PHLPP2, a negative regulators of the AKT/PI3K pathway, as a target in ESCC.

Note: This abstract was not presented at the meeting.

Citation Format: Ichiro Akagi, Osamu Ishibashi, Yota Ogawa, Toshihiro Takizawa. MiR-141-3p is upregulated in esophageal squamous cell carcinoma and targets pleckstrin homology domain leucine-rich repeat protein phosphatase-2, a negative regulator of the PI3K/AKT pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 757.

Gpr137b is an orphan G-protein-coupled receptor associated with M2 macrophage polarization

Macrophages are classified mainly into two subtypes, M1 and M2, which exhibit distinct phenotypes, based on their microenvironment. Although recent studies have suggested that G-protein-coupled receptors (GPCRs) are associated with M1/M2 macrophage polarization, available information on GPCR-mediated macrophage polarization is still limited. In the present study, we identified Gpr137b as an orphan GPCR abundantly expressed in RAW264, a mouse macrophage cell line, and illuminated its role in M2 macrophage polarization. We generated Gpr137b-knockout (Gpr137b-KO) clones of RAW264 cells using the CRISPR/Cas9 genome editing system. Two independent Gpr137b-KO clones were isolated, which were demonstrated to have frameshifting 188-nucleotide deletions at a region containing the ATG start codon of Gpr137b. Consistently, qRT-PCR analysis revealed that the deleted region is not transcribed. We then treated the Gpr137b-KO and wildtype RAW264 cells with interleukin-4 (IL-4) to induce M2 macrophage polarization. Microarray analysis revealed that the IL-4-induced gene expression of representative M2 macrophage markers was significantly reduced in the Gpr137b-KO cells, and this was validated by qRT-PCR analysis. By contrast, M1 macrophage marker gene expression induced by lipopolysaccharide was unaffected by Gpr137b-KO. Collectively, the current study shows that Gpr137b is a possible regulator of M2 macrophage polarization.

Crystal structure of the dog allergen Can f 6 and structure-based implications of its cross-reactivity with the cat allergen Fel d 4

Several dog allergens cause allergic reactions in humans worldwide. Seven distinct dog allergens, designated Canis familiaris allergen 1 to 7 (Can f 1-Can f 7), have been identified thus far. Can f 6 shows high sequence similarity and cross-reactivity with Fel d 4 and Equ c 1, major cat and horse allergens, respectively. This study was conducted on the allergenic epitopes of Can f 6 based on its structural characterization. We demonstrated that sera from 18 out of 38 (47%) dog-sensitized patients reacted to recombinant Can f 6 protein (rCan f 6). We then determined the crystal structure of rCan f 6 by X-ray crystallography, which exhibited a conserved tertiary structural architecture found in lipocalin family proteins. Based on the tertiary structure and sequence similarities with Fel d 4 and Equ c 1, we predicted three IgE-recognizing sites that are possibly involved in cross-reactivity. Substituting three successive amino acids in these sites to triple alanine decreased IgE reactivity to the allergen. However, the degree of reduction in IgE reactivity largely depended on the site mutated and the serum used, suggesting that Can f 6 is a polyvalent allergen containing multiple epitopes and Can f 6-reactive sera contain varied amounts of IgE recognising individual Can f 6 epitopes including those predicted in this study. We also demonstrated that the predicted epitopes are partly involved in IgE cross-reactivity to Fel d 4. Interestingly, the effect of the mutation depended on whether the protein was structured or denatured, indicating that the bona fide tertiary structure of Can f 6 is essential in determining its IgE epitopes.

Proteinase K treatment improves RNA recovery from thyroid cells fixed with liquid-based cytology solution

OBJECTIVE

Fine-needle aspiration biopsy (FNAB), an important diagnostic tool given its simplicity, safety, and cost-effectiveness, is fast becoming a popular procedure in the diagnosis of thyroid diseases. Generally, cells isolated from biopsies are transferred directly to microscope slides to prepare smears for cytopathological examination; however, the technical difficulties of this procedure often cause poor reproducibility, which limits the accuracy of diagnostic results. Liquid-based cytology (LBC), in which isolated cells are collected in a fixative solution, is advantageous in that it facilitates the preparation of homogenous cytological specimens. However, LBC has not been applied to molecular diagnoses, such as RNA expression-based diagnosis, mainly because of difficulties in cell recovery and RNA isolation. This study was aimed to improve RNA extraction from papillary cancer-derived K1 cells and thyroid FNAB specimens suspended in LBC solutions.

RESULTS

K1 cells suspended in CytoRich-Red and CytoRich-Blue, fixatives for LBC, were efficiently recovered by trapping to glass-fiber filters. Importantly, subsequent Proteinase K treatment was essential for efficient RNA extraction from the fixed cells. This finding was also applicable to RNA extraction from CytoRich-Red-fixed thyroid FNAB specimens processed in the same way. Consistently, U6 small nuclear RNA was detected in these RNA samples by reverse transcription-polymerase chain reaction.

Lip b 1 is a novel allergenic protein isolated from the booklouse, Liposcelis bostrychophila

BACKGROUND

Booklice, belonging to the order Psocoptera, are small household insect pests that are distributed worldwide. Liposcelis bostrychophila, a common home-inhabiting species of booklouse, infests old books, sheets of paper, and stored food. Recent entomological and serological studies demonstrated that L. bostrychophila accounted for the majority of detectable insects in house dust and could be a potent inducer of respiratory allergy. Our recent proteomic analysis identified a potent allergenic protein from L. bostrychophila, designated Lip b 1, and determined its partial amino acid sequences.

METHODS

Cloning of cDNAs for Lip b 1 was performed by large-scale transcriptome analysis (RNA-seq) and subsequent reverse transcription polymerase chain reaction. The full-length amino acid sequences deduced from Lip b 1 cDNAs were bioinformatically analyzed. The recombinant proteins of glutathione S-transferase (GST)-fused Lip b 1 were analyzed by Western blot and enzyme-linked immunosorbent assay.

RESULTS

Lip b 1 cDNAs encoding two types of 254-amino acid proteins were cloned. The clones shared 87% identity, and the deduced molecular weights and isoelectric points were consistent with those determined in our previous study. The two types of Lip b 1 proteins in the GST-fused form were similarly reactive with sera from allergic patients sensitized with L. bostrychophila.

CONCLUSIONS

Lip b 1 is a novel protein possibly causing booklouse allergy.

RNA-Seq analysis of human cell lines established from normal and neoplastic esophageal squamous epithelium

Esophageal cancer (EC) is the eighth most common cancer globally in 2012 and predominantly occurs in the man (Enzinger and Mayer, 2003; Conteduca et al., 2012). EC is classified mainly into two types, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma, accounting for 60-70% and 20-30% of all EC cases, respectively. In a previous statistical study it was reported that the numbers of new EC cases and EC-related deaths worldwide in 2008 were estimated to be 482,300 and 406,800, respectively (Jemal et al., 2011). This high mortality rate is largely due to the characteristics of EC such as frequent distant/local metastasis and poor subjective symptoms leading to difficulty with early diagnosis. Patients affected with EC diagnosed at late stages mostly have unsatisfactory prognosis, even though various therapeutic options are available. Therefore, there is an urgent need to develop effective methods that enable the early detection of EC (Orringer, 1993), prompting us to search for novel biomarkers for EC. Here, we provide datasets from RNA-Seq analysis of Het-1A, a normal human esophageal squamous cell line (Stoner et al., 1991), and TE-1, TE-5, and TE-8, which are well-, poorly-, and moderately-differentiated ESCC-derived cell lines, respectively (Nishihira et al., 1993). The raw data of these experiments have been deposited at DNA Data Bank of Japan (DDBJ) under the accession IDs DRR084199, DRR084200, DRR084201, and DRR084202.

Development of pH-Independent Drug Release Formulation Using Lipocalin-Type Prostaglandin D Synthase

The purpose of this study was to develop a pH-independent drug release formulation using lipocalin-type prostaglandin D synthase, a member of the lipocalin superfamily, with the function of forming complexes together with various small lipophilic molecules. Dipyridamole, a poorly water-soluble drug, showing a pH-dependent solubility profile, was used as the model drug. The solubilization of dipyridamole was achieved by a simple complex formulation method with lipocalin-type prostaglandin D synthase. The complex formulation was produced successfully by spray drying, and the obtained powder formulation showed complete dissolution in fasted-state simulated gastric fluid (pH, 1.6) and phosphate-buffered solution (pH, 6.8). In addition, the potential stability of the complex formulation was assessed, and the dissolution profile of the produced powder at pH 6.8 was maintained after 4-week storage under several storage conditions. Furthermore, a pharmacokinetic study using hypochlorhydria model rats was performed to verify the improvement of the intestinal absorption behavior, and eventually the complex formulation overcame the problematic absorption profile of dipyridamole in the elevated gastric pH conditions. These results, taken together, demonstrate that the use of this well-designed drug-delivery carrier is feasible for the development of pH-independent drug release formulations.

Novel Characteristics of Trypanosoma brucei Guanosine 5'-monophosphate Reductase Distinct from Host Animals

The metabolic pathway of purine nucleotides in parasitic protozoa is a potent drug target for treatment of parasitemia. Guanosine 5’-monophosphate reductase (GMPR), which catalyzes the deamination of guanosine 5’-monophosphate (GMP) to inosine 5’-monophosphate (IMP), plays an important role in the interconversion of purine nucleotides to maintain the intracellular balance of their concentration. However, only a few studies on protozoan GMPR have been reported at present. Herein, we identified the GMPR in Trypanosoma brucei, a causative protozoan parasite of African trypanosomiasis, and found that the GMPR proteins were consistently localized to glycosomes in T. brucei bloodstream forms. We characterized its recombinant protein to investigate the enzymatic differences between GMPRs of T. brucei and its host animals. T. brucei GMPR was distinct in having an insertion of a tandem repeat of the cystathionine β-synthase (CBS) domain, which was absent in mammalian and bacterial GMPRs. The recombinant protein of T. brucei GMPR catalyzed the conversion of GMP to IMP in the presence of NADPH, and showed apparent affinities for both GMP and NADPH different from those of its mammalian counterparts. Interestingly, the addition of monovalent cations such as K⁺ and NH₄⁺ to the enzymatic reaction increased the GMPR activity of T. brucei, whereas none of the mammalian GMPR’s was affected by these cations. The monophosphate form of the purine nucleoside analog ribavirin inhibited T. brucei GMPR activity, though mammalian GMPRs showed no or only a little inhibition by it. These results suggest that the mechanism of the GMPR reaction in T. brucei is distinct from that in the host organisms. Finally, we demonstrated the inhibitory effect of ribavirin on the proliferation of trypanosomes in a dose-dependent manner, suggesting the availability of ribavirin to develop a new therapeutic agent against African trypanosomiasis.

Only a limited number of therapeutics for human African trypanosomiasis also known as African sleeping sickness is available today, and it narrows the choice of the drugs to escape from the side effects and the emergence of drug-resistant pathogens. The parasitic protozoa Trypanosoma brucei is the causative reagent of African trypanosomiasis, and is infective to various mammalian species. T. brucei and its mammalian hosts share almost the same metabolic machinery, and therefore it is important to understand the differences in biochemical properties of the metabolic enzymes between T. brucei and its hosts. Here we report that guanosine 5’-monophosphate reductase (GMPR) of T. brucei showed apparent differences in its primary structure and biochemical properties from those of its host counterparts, and was more sensitive to purine nucleotide analogs such as monophosphate forms of ribavirin and mizoribine than were the host GMPRs. Furthermore, ribavirin prevented the proliferation of trypanosomes in vitro. Our present findings may imply the availability of ribavirin and/or its derivatives in a treatment of African trypanosomiasis.

Human Lipocalin-Type Prostaglandin D Synthase-Based Drug Delivery System for Poorly Water-Soluble Anti-Cancer Drug SN-38

Lipocalin-type prostaglandin D synthase (L-PGDS) is a member of the lipocalin superfamily, which is composed of secretory transporter proteins, and binds a wide variety of small hydrophobic molecules. Using this function, we have reported the feasibility of using L-PGDS as a novel drug delivery vehicle for poorly water-soluble drugs. In this study, we show the development of a drug delivery system using L-PGDS, one that enables the direct clinical use of 7-ethyl-10-hydroxy-camptothecin (SN-38), a poorly water-soluble anti-cancer drug. In the presence of 2 mM L-PGDS, the concentration of SN-38 in PBS increased 1,130-fold as compared with that in PBS. Calorimetric experiments revealed that L-PGDS bound SN-38 at a molecular ratio of 1:3 with a dissociation constant value of 60 μM. The results of an in vitro growth inhibition assay revealed that the SN-38/L-PGDS complexes showed high anti-tumor activity against 3 human cancer cell lines, i.e., Colo201, MDA-MB-231, and PC-3 with a potency similar to that of SN-38 used alone. The intravenous administration of SN-38/L-PGDS complexes to mice bearing Colo201 tumors showed a pronounced anti-tumor effect. Intestinal mucositis, which is one of the side effects of this drug, was not observed in mice administered SN-38/L-PGDS complexes. Taken together, L-PGDS enables the direct usage of SN-38 with reduced side effects.

Dataset of microarray analysis to identify endoglin-dependent bone morphogenetic protein-2-responsive genes in the murine periodontal ligament cell line PDL-L2

The periodontal ligament (PDL), connective tissue located between the cementum of teeth and alveolar bone of the mandibula, plays a crucial role in the maintenance and regeneration of periodontal tissues. We previously reported that endoglin was involved in the bone morphogenetic protein (BMP)-2-induced osteogenic differentiation of mouse PDL cells, which is associated with Smad-2 phosphorylation but not Smad-1/5/8 phosphorylation. Further, we found that the BMP-2-induced Smad-2 phosphorylation was, at least in part, dependent upon endoglin. In this study, to elucidate the detailed mechanism underlying the BMP-2-induced signaling pathway unique to PDL cells, we performed a cDNA microarray analysis to identify endoglin-dependent BMP-2-responsive genes in PDL-L2, a mouse PDL-derived cell line. Here we provide experimental methods and obtained dataset to correspond with our data in Gene Expression Omnibus (GEO) Datasets.

Complicated adult right-sided Bochdalek hernia with Chilaiditi's syndrome: a case report

An extremely rare adult case that underwent surgery for ileus caused by Bochdalek hernia associated with Chilaiditi’s syndrome is presented. A 65-year-old woman complaining of upper abdominal pain presented to our hospital. Abdominal plain radiography showed increased intestinal gas, and computed tomography (CT) showed the transverse colon located above the right lobe of the liver, representing Chilaiditi’s sign. She was diagnosed as having ileus and treated with decompression therapy by a nasoenteric tube. After hospitalization, the patient developed dyspnea, and CT showed intestinal herniation into the right thoracic cavity. She was diagnosed as having strangulated ileus caused by Bochdalek hernia. An emergent laparotomy was performed, and it showed a hole of 5 cm in diameter at the right hemi-diaphragm. The transverse colon was incarcerated through the hole, it was pulled back to the abdominal cavity, and a right hemicolectomy was performed because of necrotic changes. A small part of the liver was also herniated into the right thoracic cavity, and it was returned to the abdominal cavity. The defect in the diaphragm was closed by direct suture. Although the patient developed an abscess in the thoracic cavity postoperatively, she improved with antibiotic therapy and was discharged 2 months after the operation.

[A Case of Gastrointestinal Metastases of Breast Cancer Effectively Treated with Gemcitabine and Paclitaxel Combination Chemotherapy]

A 55-year-old woman was admitted to our hospital complaining of constipation and abdominal distention. She had a history of right breast surgery for cancer at the age of 48 years. An abdominalCT scan revealed tumors at the antrum of the stomach and the ascending colon, and the tumor at the ascending colon caused obstruction of the colon. She was diagnosed with breast cancer recurrence and was administered combination chemotherapy consisting of gemcitabine and paclitaxel. Ileus improved after this treatment, and she was discharged from the hospital and was able to receive outpatient chemotherapy. After 8 months, she experienced symptoms of ileus again, and conservative treatment was considered impossible. Therefore, she underwent distal gastrectomy and right hemicolectomy. Histological and immunohistological analyses confirmed that the tumors were breast cancer metastases. Chemotherapy with gemcitabine and paclitaxel helped our patient to return to daily life and improved her prognosis.

Isolated spleen recurrence in a patient with lung adenocarcinoma: A case report

Spleen metastasis is extremely rare in patients with lung cancer. However, recent improvements in imaging modalities may enable the antemortem diagnosis of spleen metastasis. The present study reports the case of a female patient with lung adenocarcinoma and spleen metastasis. The patient developed isolated spleen metastasis in the postoperative course. This rare metastasis was detected in a follow-up abdominal computed tomography (CT) scan without any symptoms, and was confirmed by fluorodeoxyglucose positron emission tomography (FDG-PET)/CT scan. Although very rare, chest physicians and thoracic surgeons should be alert to the possibility of spleen metastasis development when evaluating the follow-up abdominal CT scan. FDG-PET/CT scanning and an interventional approach should be considered to clarify the possibility of spleen metastasis.

miR-200a, miR-200b and miR-429 are onco-miRs that target the PTEN gene in endometrioid endometrial carcinoma

Endometrioid endometrial carcinoma (EEC) is a common malignancy of the female genital tract. However, no adequate biomarker is currently available for predicting the prognosis of this cancer. Recent studies have revealed dysregulated expression of several microRNAs (miRNAs) in various cancer tissues, and therefore, these cancer-associated miRNAs (also called onco-miRs) could be promising prognostic biomarkers of cancer progression or metastasis. In this study, in order to identify onco-miRs and their possible targets involved in EEC, we performed microarray-based integrative analyses of miRNA and mRNA expression in specimens excised from EEC lesions and adjacent normal endometrial tissues. Using integrated statistical analyses, we identified miR-200a, miR-200b and miR-429 as highly up-regulated onco-miRs in EECs. Conversely, we detected expression of a tumor-suppressor gene, phosphatase and tensin homolog (PTEN), which was predicted in silico using a miRNA-targeting mRNA prediction algorithm, as a target of the three miRNAs and which was down-regulated in EECs. Furthermore, these miRNAs were validated to target PTEN experimentally using luciferase assays and real-time polymerase chain reaction. These results suggest that the occurrence of EEC is, at least in part, mediated by miRNA-induced suppression of PTEN expression.

Identification of endoglin-dependent BMP-2-induced genes in the murine periodontal ligament cell line PDL-L2

Background

The periodontal ligament (PDL), connective tissue located between the cementum of teeth and alveolar bone of the mandibula, plays an important role in the maintenance and regeneration of periodontal tissues. We reported previously that endoglin was involved in the BMP-2-induced osteogenic differentiation of mouse PDL cells, which is associated with Smad-2 phosphorylation but not Smad-1/5/8 phosphorylation. In this study, to elucidate the detailed mechanism underlying the BMP-2 signalling pathway unique to PDL cells, we performed a microarray analysis to identify BMP-2-inducible genes in PDL-L2 cells, a mouse PDL-derived cell line, with or without endoglin knockdown.

Findings

Sixty-four genes were upregulated more than twofold by BMP-2 in PDL-L2 cells. Of these genes, 11 were endoglin-dependent, including Id4, which encodes ID4, a helix-loop-helix transcription factor closely associated with TGF-β signaling and osteoblast differentiation. The endoglin-dependent induction of ID4 by BMP-2 was also verified at a protein level.

Conclusion

Our findings indicate that ID4 could be a signal mediator involved in the BMP-2-induced endoglin-dependent osteogenic differentiation of PDL cells.

Interactions between the non-seed region of siRNA and RNA-binding RLC/RISC proteins, Ago and TRBP, in mammalian cells

Small interfering RNA (siRNA)-based RNA interference (RNAi) is widely used for target gene silencing in various organisms. We previously showed that 8-nt-long 5′ proximal nucleotides, which include seed sequence (positions 2–8 from the 5′ end of guide strand), and the complementary sequence of the passenger strand are capable of being simultaneously replaced with cognate deoxyribonucleotides without any substantial loss of gene silencing. In the present study, examination was made of RNA requirements in the non-seed region of siRNA. The non-seed region of siRNA was found to be subdivided into four domains, in which two nucleotide pairs (positions 13 and 14) were replaceable with cognate deoxyribonucleotides without reducing RNAi activity. However, RNA sequences at positions 9-12 and 15-18 were essential for effective gene silencing, and these two double-stranded RNA cores are required for binding of the trans-activation response RNA-binding protein (TRBP). The terminal RNA (positions 19–21) provided Argonaute protein binding sites. Argonaute binding was enhanced by the presence of RNAs at positions 15–18. Knockdown experiments showed that, unlike Argonaute and TRBP, Dicer was dispensable for RNAi. Based on these observations, we discuss possible RNA/protein and protein/protein interactions in RNA-induced silencing complex formation.

Bone Morphogenetic Protein-2 Desensitizes MC3T3-E1 Osteoblastic Cells to Estrogen Through Transcriptional Downregulation of Estrogen Receptor 1

Background

Estrogens exert preferable effects on bone metabolism through two estrogen receptors (ERs), ER1 and ER2, which activate the transcription of a set of genes as ligand-dependent transcription factors. Thus, growth factors and hormones which modulate ER expression in the bone, if any, may possibly modulate the effect of estrogens on bone metabolism. However, research as to which of these molecules regulate the expression of ERs in osteoblasts has not been well documented.

Methods

A reporter assay system developed in this study was used to explore molecules that modulate ER1 expression in MC3T3-E1 osteoblastic cells. Gene expression was analyzed by reverse transcription-polymerase chain reaction.

Results

A pilot study using the reporter system revealed that bone morphogenetic protein (BMP)-2 negatively regulated ER1, but not ER2, expression in MC3T3-E1 cells. Consistently, estradiol-induced reporter activity via an estrogen responsive element was strongly suppressed in MC3T3-E1 cells pretreated with BMP-2.

Conclusions

BMP-2 desensitizes osteoblastic cells to estrogen through downregulation of ER1 expression.

Plasma level of hydroxysteroid (17-β) dehydrogenase 1 in the second trimester is an independent risk factor for predicting preeclampsia after adjusting for the effects of mean blood pressure, bilateral notching and plasma level of soluble fms-like tyrosine kinase 1/placental growth factor ratio

Mean blood pressure (MBP), bilateral notching (BN) in the uterine artery and increased circulating levels of soluble fms-like tyrosine kinase-1/placental growth factor (sFlt-1/PlGF) ratio are predictors of preeclampsia (PE). Recently, we disclosed that reducing the plasma level of hydroxysteroid (17-β) dehydrogenase 1 (HSD17B1), which is a steroidogenetic enzyme catalyzing the conversion of estrone to 17β-estradiol, is a potential prognostic factor for PE. Our aim was to evaluate whether HSD17B1 is an independent risk factor for predicting PE after adjusting for the effects of MBP, BN and the plasma level of the sFlt-1/PlGF ratio in the second trimester. One hundred and twenty-eight consecutive normal pregnant women without gestational hypertension (GH) or PE and 30 women with PE were selected from 1724 pregnant women. Multivariate logistic regression with a forward stepwise procedure was used to construct a prediction model. A past history of GH/PE, a family history of hypertension, pre-pregnancy body mass index, MBP, BN, plasma levels of sFlt-1/PlGF ratio and plasma levels of HSD17B1 were significantly associated with the occurrence of PE; however, only MBP (OR (95% confidence interval), 1.08 (1.03-1.14)), BN (7.5 (1.9-30)), sFlt-1/PlGF (21 (2.7-163)) and HSD17B1 (0.43 (0.22-0.85)) were independent risk factors for PE. The area under the receiver-operating-characteristic curve for the combination model was 0.89, yielding a sensitivity of 0.84, a specificity of 0.88 and a positive likelihood ratio of 7.2 (4.0-13). In conclusion, HSD17B1 is an independent risk factor for PE, and the combination of several risk factors including HSD17B1 in the second trimester may improve the prediction of PE.

MiR-21 is enriched in the RNA-induced silencing complex and targets COL4A1 in human granulosa cell lines

MicroRNAs (miRNAs) are noncoding small RNAs that play important roles in a variety of physiological and pathological events. In this study, we performed large-scale profiling of EIF2C2-bound miRNAs in 3 human granulosa-derived cell lines (ie, KGN, HSOGT, and GC1a) by high-throughput sequencing and found that miR-21 accounted for more than 80% of EIF2C2-bound miRNAs, suggesting that it was enriched in the RNA-induced silencing complex (RISC) and played a functional role in human granulosa cell (GC) lines. We also found high expression levels of miR-21 in primary human GCs. Assuming that miR-21 target mRNAs are enriched in RISC, we performed cDNA cloning of EIF2C2-bound mRNAs in KGN cells. We identified COL4A1 mRNA as a miR-21 target in the GC lines. These data suggest that miR-21 is involved in the regulation of the synthesis of COL4A1, a component of the basement membrane surrounding the GC layer and granulosa-embedded extracellular structure.

Hydroxysteroid (17-β) dehydrogenase 1 is dysregulated by miR-210 and miR-518c that are aberrantly expressed in preeclamptic placentas: a novel marker for predicting preeclampsia

In this study, to search for novel preeclampsia (PE) biomarkers, we focused on microRNA expression and function in the human placenta complicated with PE. By comprehensive analyses of microRNA expression, we identified 22 microRNAs significantly upregulated in preeclamptic placentas, 5 of which were predicted in silico to commonly target the mRNA encoding hydroxysteroid (17-β) dehydrogenase 1 (HSD17B1), a steroidogenetic enzyme expressed predominantly in the placenta. In vivo HSD17B1 expression, at both the mRNA and protein levels, was significantly decreased in preeclamptic placentas. Of these microRNAs, miR-210 and miR-518c were experimentally validated to target HSD17B1 by luciferase assay, real-time PCR, and ELISA. Furthermore, we found that plasma HSD17B1 protein levels in preeclamptic pregnant women reflected the decrease of its placental expression. Moreover, a prospective cohort study of plasma HSD17B1 revealed a significant reduction of plasma HSD17B1 levels in pregnant women at 20 to 23 and 27 to 30 weeks of gestation before PE onset compared with those with normal pregnancies. The sensitivities/specificities for predicting PE at 20 to 23 and 27 to 30 weeks of gestation were 0.75/0.67 (cutoff value=21.9 ng/mL) and 0.88/0.51 (cutoff value=30.5 ng/mL), and the odds ratios were 6.09 (95% CI: 2.35-15.77) and 7.83 (95% CI: 1.70-36.14), respectively. We conclude that HSD17B1 is dysregulated by miR-210 and miR-518c that are aberrantly expressed in preeclamptic placenta and that reducing plasma level of HSD17B1 precedes the onset of PE and is a potential prognostic factor for PE.

Short RNA duplexes elicit RIG-I-mediated apoptosis in a cell type- and length-dependent manner

Short double-stranded RNAs (dsRNAs) induce type I interferon (IFN)-mediated innate immune responses. In functional studies with short interfering RNAs or synthetic mimics of microRNA precursors in vitro, we found that short dsRNAs readily induced apoptosis in cells derived from human granulosa cell tumors, but not in other cell types. Apoptosis was independent of the sequence of the dsRNA, but depended on its length, and was induced by 23- and 24-nucleotide (nt) dsRNAs, but not by shorter dsRNAs (< 22 nt) or by the long dsRNA polyinosinic-polycytidylic acid. Microarray analysis revealed that apoptosis was accompanied by the increased expression of IFN-stimulated genes; however, several lines of evidence showed that IFNs did not directly induce apoptosis. Subsequent analyses revealed that the short dsRNAs increased the expression of retinoic acid-inducible gene I (RIG-I) through dsRNA-activated protein kinase (PKR). Although these dsRNAs bore 3' overhangs and nontriphosphate 5' termini, which are not thought to be RIG-I-activating structures, the dsRNAs bound to RIG-I and triggered proapoptotic signaling mostly by activating RIG-I, which was followed by activation of the mitogen-activated protein kinase p38. Thus, we suggest that ligand recognition and subsequent signaling by RNA sensors are more complicated than previously believed. In addition, short dsRNAs may serve as pharmacological agents to target specific tumors, such as granulosa cell tumors.

Relationship between altered expression levels of MIR21, MIR143, MIR145, and MIR205 and clinicopathologic features of esophageal squamous cell carcinoma

In spite of the undisputed importance of altered expression patterns of microRNAs (miRNAs) in various cancers, there is little information on the clinicopathologic significance of cancer-related miRNAs (MIR21, MIR143, MIR144, MIR145, and MIR205) in esophageal squamous cell carcinoma (ESCC). We examined the expression levels of the precursor and mature miRNA genes in ESCC using real-time polymerase chain reaction (PCR). We also investigated the mRNA expression levels of processing elements (RNASEN, DGCR8, and DICER1) that participate in miRNA-biogenesis pathway. Furthermore, we analyzed the relationships between the expression levels of these five miRNAs and the clinicopathologic parameters of ESCC patients. The expression levels of mature MIR21 and mature MIR145 were higher in ESCC than those in normal epithelium (P < 0.05). The mature/pre ratio of MIR21 in ESCC was higher than that in normal epithelium (P < 0.05). With regard to miRNA-processing elements, the expression level of RNASEN was higher in ESCC than in normal epithelium (P < 0.05). Furthermore, altered expression of these miRNAs was related to the clinicopathologic features of ESCC patients. The high expression of mature MIR21 and mature MIR205 was associated with lymph node positivity in ESCC patients (P < 0.05). The high levels of expression of mature MIR143 and mature MIR145 were associated with recurrence of metastasis in ESCC patients (P < 0.05). The findings may imply that miRNA biogenesis is aberrantly accelerated in ESCC. Analysis of the expression levels of miRNAs should provide useful information for evaluation of the staging, prognosis, and treatment of ESCC patients.

Identification of obstructive jaundice-related microRNAs in mouse liver

BACKGROUND/AIMS

Although microRNAs are known to be post-transcriptional regulators in physiological and pathological events in the liver, their role in the obstructive jaundice liver remains unclear.

METHODOLOGY

We sequenced the small RNA libraries of the bile duct ligation (BDL) mouse liver to detect the in vivo microRNA expression profiles of obstructive jaundice. We also validated the differential expression of microRNAs in the BDL liver using real-time PCR. Laser microdissection was performed to identify the origin of BDL-related microRNAs. An IL6-treated normal intrahepatic biliary epithelial cell line was used as an in vitro model of obstructive jaundice.

RESULTS

We found microRNAs that were upregulated in the BDL liver (let-7a, let-7d, let-7f, let-7g, miR-21, miR-125a-5p, miR-125b-5p, miR-194, miR-199a-3p, miR-199a-5p, miR-214, miR-221, and miR-486). Furthermore, laser-microdissection analysis showed that miR-199a-5p was significantly upregulated in the intrahepatic bile duct of the BDL liver. The in vitro expression of miR-199a-5p was appreciably elevated in accordance with increased proliferation of IL6-treated cells.

CONCLUSIONS

We revealed dynamic changes in microRNA expression during obstructive jaundice using the BDL model. MiR-199a-5p was likely associated with the proliferation of intrahepatic bile ducts. Our data will facilitate further study of the pathophysiological role(s) of microRNAs in the obstructive jaundice liver.

Endoglin is involved in BMP-2-induced osteogenic differentiation of periodontal ligament cells through a pathway independent of Smad-1/5/8 phosphorylation

The periodontal ligament (PDL), a connective tissue located between the cementum of teeth and the alveolar bone of mandibula, plays a crucial role in the maintenance and regeneration of periodontal tissues. The PDL contains fibroblastic cells of a heterogeneous cell population, from which we have established several cell lines previously. To analyze characteristics unique for PDL at a molecular level, we performed cDNA microarray analysis of the PDL cells versus MC3T3-E1 osteoblastic cells. The analysis followed by validation by reverse transcription-polymerase chain reaction and immunochemical staining revealed that endoglin, which had been shown to associate with transforming growth factor (TGF)-beta and bone morphogenetic proteins (BMPs) as signaling modulators, was abundantly expressed in PDL cells but absent in osteoblastic cells. The knockdown of endoglin greatly suppressed the BMP-2-induced osteoblastic differentiation of PDL cells and subsequent mineralization. Interestingly, the endoglin knockdown did not alter the level of Smad-1/5/8 phosphorylation induced by BMP-2, while it suppressed the BMP-2-induced expression of Id1, a representative BMP-responsive gene. Therefore, it is conceivable that endoglin regulates the expression of BMP-2-responsive genes in PDL cells at some site downstream of Smad-1/5/8 phosphorylation. Alternatively, we found that Smad-2 as well as Smad-1/5/8 was phosphorylated by BMP-2 in the PDL cells, and that the BMP-2-induced Smad-2 phosphorylation was suppressed by the endoglin knockdown. These results, taken together, raise a possibility that PDL cells respond to BMP-2 via a unique signaling pathway dependent on endoglin, which is involved in the osteoblastic differentiation and mineralization of the cells.

MicroRNA profiling of human intrahepatic cholangiocarcinoma cell lines reveals biliary epithelial cell-specific microRNAs

Intrahepatic cholangiocarcinoma (ICC), which arises in the small bile ducts of the liver, is the second most common liver malignancy. Although modulation of microRNA (miRNA) expression has been shown to be a potent sign of malignant tumors, miRNA profiles of ICC remains unclear. We performed sequencing analysis of the small RNA libraries of 2 ICC cell lines (HuCCT1 and MEC) and one normal intrahepatic biliary epithelial cell line (HIBEpiC) to produce the miRNA profiles of ICC in vitro. Furthermore, by means of the real-time polymerase chain reaction (PCR) we validated the differential expression of miRNAs cloned exclusively or predominantly from each of the cell lines. A total of 35,759 small RNA clones were obtained from the 3 cell lines. We identified 27 miRNAs that were expressed exclusively or predominantly in each cell line. Subsequent validation with the real-time PCR confirmed that the miRNAs hsa-miR-22, -125a, -127, -199a, -199a*, -214, -376a, and -424 were expressed specifically in HIBEpiC but were downregulated in the ICC cell lines. Our study provides important information for facilitating studies of the functional role(s) of miRNAs in carcinogenesis of the hepatobiliary system. The biliary epithelial cell-specific miRNAs identified in this study may serve as potential biomarkers for ICC.

Human villous trophoblasts express and secrete placenta-specific microRNAs into maternal circulation via exosomes

In this study, we performed small RNA library sequencing using human placental tissues to identify placenta-specific miRNAs. We also tested the hypothesis that human chorionic villi could secrete miRNAs extracellularly via exosomes, which in turn enter into maternal circulation. By small RNA library sequencing, most placenta-specific miRNAs (e.g., MIR517A) were linked to a miRNA cluster on chromosome 19. The miRNA cluster genes were differentially expressed in placental development. Subsequent validation by real-time PCR and in situ hybridization revealed that villous trophoblasts express placenta-specific miRNAs. The analysis of small RNA libraries from the blood plasma showed that the placenta-specific miRNAs are abundant in the plasma of pregnant women. By real-time PCR, we confirmed the rapid clearance of the placenta-specific miRNAs from the plasma after delivery, indicating that such miRNAs enter into maternal circulation. By using the trophoblast cell line BeWo in culture, we demonstrated that miRNAs are indeed extracellularly released via exosomes. Taken together, our findings suggest that miRNAs are exported from the human placental syncytiotrophoblast into maternal circulation, where they could target maternal tissues. Finally, to address the biological functions of placenta-specific miRNAs, we performed a proteome analysis of BeWo cells transfected with MIR517A. Bioinformatic analysis suggests that this miRNA is possibly involved in tumor necrosis factor-mediated signaling. Our data provide important insights into miRNA biology of the human placenta.

Chondromodulin-1 directly suppresses growth of human cancer cells

Background

Chondromodulin-1 (ChM1), an endogenous anti-angiogenic factor expressed in cartilage, has been suggested to inhibit invasion of endothelial cells into cartilage. In addition, the ectopic administration of ChM1 has been reported to suppress tumorigenesis in vivo. However, it is unclear whether the anti-tumor effect is due to not only the anti-vascularization effect of ChM1, but also its direct action against oncocytes. In the present study, we sought to determine whether ChM1 has a direct action on tumor cells.

Methods

BrdU incorporation assay was performed on human umbilical vein endothelial cells (HUVECs), normal human dermal fibroblasts (NHDFs), HepG2 cells and HeLa cells in the presence or absence of recombinant human ChM1 (rhChM1). An adenovirus that expresses ChM1, Ad-ChM1, was established and applied to the tumor xenografted in vivo, and to in vitro tumor cells cultured on plates or in soft agar. Cell cycle-related proteins and the phosphorylation of Erk, Akt, and GSK3β, the downstream molecules of the extracellular matrix-integrin signaling pathways, in HepG2 cells treated with or without Ad-ChM1 were detected by western blot analysis. Luciferase reporter assays of STAT, GAS, and ISRE, which participate in another cytokine signaling pathway, ware performed in HepG2, HeLa, and HUVEC cells.

Results

ChM1 suppressed BrdU incorporation in HUVECs and in HepG2 cells dose-dependently, but did not suppress BrdU incorporation in NHDFs and HeLa cells cultured on plates. In soft agar, however, ChM1 suppressed the growth of HeLa cells, as well as HepG2 cells. Western blot analyses demonstrated that ChM1 decreased the levels of cyclin D1, cyclin D3, and cdk6 and increased those of p21^cip1 without affecting the phosphorylation levels of Erk, Akt, and GSK3β in HepG2 cells. The luciferase reporter assay demonstrated that ChM1 suppressed the transcriptional activities of STAT and GAS but not of ISRE.

Conclusion

ChM1 directly suppressed the proliferation of tumor cells in an anchorage-independent manner. However, ChM1 did not alter the phosphorylation of downstream molecules, at which the signaling pathways through growth factor and cytokine receptors converge with the anchorage-dependent pathway. Our results show that ChM1 has a direct anti-tumor effect; moreover, this effect occurs by inhibiting the STAT signaling pathway.

MicroRNA (miRNA) cloning analysis reveals sex differences in miRNA expression profiles between adult mouse testis and ovary

MicroRNAs (miRNAs) are endogenous non-coding small RNAs that can regulate the expression of complementary mRNA targets. Identifying tissue-specific miRNAs is the first step toward understanding the biological functions of miRNAs, which include the regulation of tissue differentiation and the maintenance of tissue identity. In this study, we performed small RNA library sequencing in adult mouse testis and ovary to reveal their characteristic organ- and gender-specific profiles and to elucidate the characteristics of the miRNAs expressed in the reproductive system. We obtained 10,852 and 11 744 small RNA clones from mouse testis and ovary respectively (greater than 10,000 clones per organ), which included 6630 (159 genes) and 10,192 (154 genes) known miRNAs. A high level of efficiency of miRNA library sequencing was achieved: 61% (6630 miRNA clones/10,852 small RNA clones) and 87% (10,192/11,744) for adult mouse testis and ovary respectively. We obtained characteristic miRNA signatures in testis and ovary; 55 miRNAs were detected highly, exclusively, or predominantly in adult mouse testis and ovary, and discovered two novel miRNAs. Male-biased expression of miRNAs occurred on the X-chromosome. Our data provide important information on sex differences in miRNA expression that should facilitate studies of the reproductive organ-specific roles of miRNAs.

PIASxbeta is a key regulator of osterix transcriptional activity and matrix mineralization in osteoblasts

We recently reported that tensile stress induces osteoblast differentiation and osteogenesis in the mouse calvarial suture in vitro. Using this experimental system, we identified PIASxbeta, a splice isoform of Pias2, as one of the genes most highly upregulated by tensile stress. Further study using cell culture revealed that this upregulation was transient and was accompanied by upregulation of other differentiation markers, including osterix, whereas expression of Runx2 was unaffected. Runx2 and osterix are the two master proteins controlling osteoblast differentiation, with Runx2 being upstream of osterix. Targeted knockdown of PIASxbeta by small interfering RNA (siRNA) markedly suppressed osteoblastic differentiation and matrix mineralization, whereas transient overexpression of PIASxbeta caused the exact opposite effects. Regardless of PIASxbeta expression level, Runx2 expression remained constant. Reporter assays demonstrated that osterix enhanced its own promoter activity, which was further stimulated by PIASxbeta but not by its sumoylation-defective mutant. NFATc1 and NFATc3 additionally increased osterix transcriptional activity when co-transfected with PIASxbeta. Because osterix has no consensus motif for sumoylation, other proteins are probably involved in the PIASxbeta-mediated activation and NFAT proteins may be among such targets. This study provides the first line of evidence that PIASxbeta is indispensable for osteoblast differentiation and matrix mineralization, and that this signaling molecule is located between Runx2 and osterix.