Tumour-suppressive miRNA-26a-5p and miR-26b-5p inhibit cell aggressiveness by regulating PLOD2 in bladder cancer

BACKGROUND

Previous studies have revealed that miR-26a-5p and miR-26b-5p act as tumour suppressors in various types of cancer tissues. Here, we aimed to investigate the functional roles of these miRNAs and to identify their regulatory targets in bladder cancer (BC).

METHODS

We performed functional assays in BC cells using transfection of mature microRNAs (miRNAs). In silico and luciferase reporter analyses were applied to identify target genes of these miRNAs. The overall survival (OS) of patients with BC was evaluated by the Kaplan-Meier method.

RESULTS

miR-26a-5p and miR-26b-5p were significantly downregulated in BC tissues. Restoration of these miRNAs inhibited cell migration and invasion in BC. The gene encoding procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2), a collagen crosslinking enzyme, was directly regulated by miR-26a-5p and miR-26b-5p. Kaplan-Meier analysis revealed that patients with high PLOD2 expression had significantly shorter OS compared with those with low PLOD2 expression (P=0.0153).

CONCLUSIONS

PLOD2, which is associated with the stiffness of the extracellular matrix, was directly regulated by miR-26a-5p and miR-26b-5p and may be a good prognostic marker in patients with BC.

Refractive index determination by coherence scanning interferometry

Coherence scanning interferometry is established as a powerful noncontact, three-dimensional, metrology technique used to determine accurate surface roughness and topography measurements with subnanometer precision. The helical complex field (HCF) function is a topographically defined helix modulated by the electrical field reflectance, originally developed for the measurement of thin films. An approach to extend the capability of the HCF function to determine the spectral refractive index of a substrate or absorbing film has recently been proposed. In this paper, we confirm this new capability, demonstrating it on surfaces of silicon, gold, and a gold/palladium alloy using silica and zirconia oxide thin films. These refractive index dispersion measurements show good agreement with those obtained by spectroscopic ellipsometry.

Massive bowel resection upregulates the intestinal mRNA expression levels of cellular retinol-binding protein II and apolipoprotein A-IV and alters the intestinal vitamin A status in rats

Short bowel (SB) syndrome causes the malabsorption of various nutrients. Among these, vitamin A is important for a number of physiological activities. Vitamin A is absorbed by epithelial cells of the small intestine and is discharged into the lymphatic vessels as a component of chylomicrons and is delivered to the liver. In the present study, we used a rat model of SB syndrome in order to assess its effects on the expression of genes associated with the absorption, transport and metabolism of vitamin A. In the rats with SB, the intestinal mRNA expression levels of cellular retinol-binding protein II (CRBP II, gene symbol Rbp2) and apolipoprotein A-IV (gene symbol Apoa4) were higher than those in the sham-operated rats, as shown by RT-qPCR. Immunohistochemical analysis revealed that absorptive epithelial cells stained positive for both CRBP II and lecithin retinol acyltransferase, which are both required for the effective esterification of vitamin A. In the rats with SB, the retinol content in the ileum and the retinyl ester content in the jejunum were lower than those in the sham-operated rats, as shown by quantitative analysis of retinol and retinyl esters by high performance liquid chromatography. These results suggest that the elevated mRNA expression levels of Rbp2 and Apoa4 in the rats with SB contribute to the effective esterification and transport of vitamin A.

Indoor air quality and thermal comfort in temporary houses occupied after the Great East Japan Earthquake

Thermal conditions and indoor concentrations of aldehydes, volatile organic compounds (VOCs), and NO2 were investigated in 19 occupied temporary houses in 15 temporary housing estates constructed in Minamisoma City, Fukushima, Japan. The data were collected in winter, spring, and summer in January to July 2012. Thermal conditions in temporary log houses in the summer were more comfortable than those in pre-fabricated houses. In the winter, the indoor temperature was uncomfortably low in all of the houses, particularly the temporary log houses. Indoor air concentrations for most aldehydes and VOCs were much lower than the indoor guidelines, except for those of p-dichlorobenzene, acetaldehyde, and total VOCs. The indoor p-dichlorobenzene concentrations exceeded the guideline (240 μg/m(3)) in 18% of the temporary houses, and the 10(-3) cancer risk level (91 μg/m(3)) was exceeded in winter in 21% due to use of moth repellents by the occupants. Indoor acetaldehyde concentrations exceeded the guideline (48 μg/m(3) ) in about half of the temporary houses, likely originating from the wooden building materials. Indoor NO2 concentrations in the temporary houses were significantly higher in houses where combustion heating appliances were used (0.17 ± 0.11 ppm) than in those where they were not used (0.0094 ± 0.0065 ppm).

PRACTICAL IMPLICATIONS

In the winter, log-house-type temporary houses are comfortable in terms of humidity, dew condensation, and fungi based on the results of questionnaires and measurements, whereas pre-fabricated temporary houses are more comfortable in terms of temperature. In the summer, log-house-type temporary houses are comfortable in terms of temperature and humidity. More comfortable temporary housing in terms of temperature and humidity year-round is needed. Indoor air concentrations of p-dichlorobenzene and NO2 were quite high in some temporary houses due to occupants’ activities, such as use of moth repellents and combustion heating appliances. The government should provide recommendations for safe use of temporary houses by occupants.

Preparation And Characterization Of Some Nickel 1,2-Dithiolene Complexes As Single-Component Semiconductors

The unsymmetrical (mixed-ligand) nickel 1,2-dithiolene complexes Ni(pddt)(dmio) and Ni(pddt)(dmit) (where pddt is 6,7-dihydro-5H-1,4-dithiepin-2,3-dithiolate, dmio is 1,3-dithiol-2-one- 4,5-dithiolate, and dmit is 1,3-dithiol-2-thione-4,5-dithiolate) were synthesized and characterized. The new complexes were found to be soluble in organic solvents, from which single crystals and/or thin deposits can be obtained. In the solid state, the compounds behave as single-component semiconductors with low room temperature conductivity values

Differential increases in the expression of intermediate filament proteins and concomitant morphological changes of transdifferentiating rat hepatic stellate cells observed in vitro

The primary function of hepatic stellate cells (HSCs) is the storage of vitamin A. However, they are also responsible for liver fibrosis and are therapeutic targets for treatment of liver cirrhosis. Among the many molecular markers that define quiescent or activated states of HSCs, the characteristics of type III intermediate filaments are of particular interest. Whereas vimentin and desmin are upregulated in activated HSCs, glial fibrillary acidic protein is downregulated in activated HSCs. The functional differences between vimentin and desmin are poorly understood. By time-course quantifications of several molecular markers for HSC activation, we observed that the expression of vimentin preceded that of desmin during the transdifferentiation of HSCs. The immunoreactivity of vimentin in transdifferentiated HSCs was more intense in perinuclear regions compared to that of desmin. We propose that the delayed expression of desmin following the expression of vimentin and the peripheral localization of desmin compared to vimentin are both related to the more extended phenotype of transdifferentiating HSCs observed in vitro.

Tumour-suppressive microRNA-29s inhibit cancer cell migration and invasion by targeting laminin-integrin signalling in head and neck squamous cell carcinoma

Background:

Our recent studies of microRNA (miRNA) expression signatures demonstrated that microRNA-29s (miR-29s; miR-29a/b/c) were significantly downregulated in head and neck squamous cell carcinoma (HNSCC) and were putative tumour-suppressive miRNAs in human cancers. Our aim in this study was to investigate the functional significance of miR-29s in cancer cells and to identify novel miR-29s-mediated cancer pathways and responsible genes in HNSCC oncogenesis and metastasis.

Methods:

Gain-of-function studies using mature miR-29s were performed to investigate cell proliferation, migration and invasion in two HNSCC cell lines (SAS and FaDu). To identify miR-29s-mediated molecular pathways and targets, we utilised gene expression analysis and in silico database analysis. Loss-of-function assays were performed to investigate the functional significance of miR-29s target genes.

Results:

Restoration of miR-29s in SAS and FaDu cell lines revealed significant inhibition of cancer cell migration and invasion. Gene expression data and in silico analysis demonstrated that miR-29s modulated the focal adhesion pathway. Moreover, laminin γ2 (LAMC2) and α6 integrin (ITGA6) genes were candidate targets of the regulation of miR-29s. Luciferase reporter assays showed that miR-29s directly regulated LAMC2 and ITGA6. Silencing of LAMC2 and ITGA6 genes significantly inhibited cell migration and invasion in cancer cells.

Conclusion:

Downregulation of miR-29s was a frequent event in HNSCC. The miR-29s acted as tumour suppressors and directly targeted laminin–integrin signalling. Recognition of tumour-suppressive miRNA-mediated cancer pathways provides new insights into the potential mechanisms of HNSCC oncogenesis and metastasis and suggests novel therapeutic strategies for the disease.

Indoor air quality, air exchange rates, and radioactivity in new built temporary houses following the Great East Japan Earthquake in Minamisoma, Fukushima

This study measured air exchange rates, indoor concentrations of aldehydes and volatile organic compounds (VOCs), and radioactivity levels at 19 temporary houses in different temporary housing estate constructed in Minamisoma City following the Great East Japan Earthquake. The 19 surveyed houses represented all of the companies assigned to construct temporary houses in that Minamisoma City. Data were collected shortly after construction and before occupation, from August 2011 to January 2012. Mean air exchange rates in the temporary houses were 0.28/h, with no variation according to housing types and construction date. Mean indoor concentrations of formaldehyde, acetaldehyde, toluene, ethylbenzene, m/p-xylene, o-xylene, styrene, p-dichlorobenzene, tetradecane, and total VOCs (TVOCs) were 29.2, 72.7, 14.6, 6.35, 3.05, 1.81, 7.29, 14.3, 8.32, and 901 μg/m(3), respectively. The levels of acetaldehyde and TVOCs exceeded the indoor guideline (48 μg/m(3)) and interim target (400 μg/m(3)) in more than half of the 31 rooms tested. In addition to guideline chemicals, terpenes (α-pinene and d-limonene) and acetic esters (butyl acetate and ethyl acetate) were often detected in these houses. The indoor radiation levels measured by a Geiger-Müller tube (Mean: 0.22 μSv/h) were lower than those recorded outdoors (Mean: 0.42 μSv/h), although the shielding effect of the houses was less than for other types of buildings.

The role of retinoic acid receptors in activated hepatic stellate cells

Hepatic stellate cells (HSCs), also known as Ito cells, fat-storing cells, vitamin A-storing cells or lipocytes, reside in the spaces between hepatocytes and liver sinusoids. Vitamin A storage within the HSCs is achieved through the cooperative action of two proteins, cellular retinol-binding protein (CRBP) I and lecithin:retinol acyltransferase (LRAT). After the discovery that HSCs are responsible not only for the storage of vitamin A, but also for the development of liver fibrosis and subsequent liver cirrhosis, HSCs have been considered a therapeutic target for prevention or reversal of liver fibrogenesis. We have reported that HSCs acquire retinoid responsiveness after in vitro activation by post-transcriptional upregulation of retinoic acid receptor α gene expression. Here we extend this observation in relation to the functions of CRBP I and LRAT, and propose a hypothesis that increased retinoid signaling in activated HSCs forms a feedback loop toward vitamin A restoration in the liver.

Tumour-suppressive microRNA-874 contributes to cell proliferation through targeting of histone deacetylase 1 in head and neck squamous cell carcinoma

BACKGROUND

Our recent studies of microRNA (miRNA) expression signature demonstrated that microRNA-874 (miR-874) was significantly downregulated in maxillary sinus squamous cell carcinoma (MSSCC), and a putative tumour-suppressive miRNA in human cancers. Our aim of this study was to investigate the functional significance of miR-874 in cancer cells and to identify novel miR-874-mediated cancer pathways and responsible genes in head and neck squamous cell carcinoma (HNSCC).

METHODS

Gain-of-function studies using mature miR-874 were performed to investigate cell proliferation and cell cycle distribution in HNSCC cell lines (SAS and FaDu). To identify miR-874-mediated molecular pathways and targets, we utilised gene expression analysis and in silico database analysis. Loss-of-function assays were performed to investigate the functional significance of miR-874 target genes.

RESULTS

Expression levels of miR-874 were significantly downregulated in HNSCC tissues (including oral, pharyngeal and laryngeal SCCs) compared with normal counterpart epithelia. Restoration of miR-874 in SAS and FaDu cell lines revealed significant inhibition of cell proliferation and induction of G2/M arrest and cell apoptosis. Our expression data and in silico analysis demonstrated that miR-874 modulated the cell cycle pathway. Moreover, histone deacetylase 1 (HDAC1) was a candidate target of miR-874 regulation. Luciferase reporter assays showed that miR-874 directly regulated HDAC1. Silencing of the HDAC1 gene significantly inhibited cell proliferation and induced G2/M arrest and cell apoptosis in SAS cells.

CONCLUSIONS

Downregulation of miR-874 was a frequent event in HNSCC. miR-874 acted as a tumour suppressor and directly targeted HDAC1. Recognition of tumour-suppressive miRNA-mediated cancer pathways provides new insights into the potential mechanisms of HNSCC oncogenesis and suggests novel therapeutic strategies for the disease.

Response of the Nrf2 protection system in human monocytic cells after ionising irradiation

In response to reactive oxygen species (ROS) or electrophiles, the transcription factor nuclear factor-erythroid 2 (NF-E2)-related factor 2 (Nrf2) rapidly translocates into the nucleus and induces the expression of various antioxidant genes, such as heme oxygenase-1 (HO-1). Low linear energy transfer (LET) ionising radiations such as X-rays generate ROS, which cause biological damage. However, little is known about whether the Nrf2 system in human monocytic cells is activated by low LET ionising irradiation. Therefore, in this study, the response of the Nrf2 system to X-irradiation in human monocytic THP1 cells was investigated. Following exposure of THP1 cells to X-rays (1-5 Gy), intracellular ROS levels were measured using 2',7'-dichlorodihydrofluorescein diacetate, Nrf2 localisation was determined using immunofluorescence staining and HO-1 mRNA and protein expression were examined. Although ROS were generated by irradiation in a dose-dependent manner, they disappeared immediately after irradiation. Nrf2 translocation into the nucleus was observed 6 h after 5 Gy X-irradiation but was not detected following 1-2 Gy irradiation or in non-irradiated controls. HO-1 expression was significantly higher in 5 Gy-irradiated cells after 24 h than in non-irradiated controls. These results indicate that high-dose irradiation (5 Gy) activates Nrf2 and that the Nrf2 protection system may function from 24 h after irradiation in human monocytic cells.

Pressure-induced colossal piezoresistance effect and the collapse of the polaronic state in the bilayer manganite (La(0.4)Pr(0.6))(1.2)Sr(1.8)Mn2O7

We have investigated the effect of hydrostatic pressure as a function of temperature on the resistivity of a single crystal of the bilayer manganite (La(0.4)Pr(0.6))(1.2)Sr(1.8)Mn(2)O(7). Whereas a strong insulating behaviour is observed at all temperatures at ambient pressure, a clear transition into a metallic-like behaviour is induced when the sample is subjected to a pressure (P) of ~1.0 GPa at T < 70 K. A huge negative piezoresistance ~10(6) in the low temperature region at moderate pressures is observed. When the pressure is increased further (5.5 GPa), the high temperature polaronic state disappears and a metallic behaviour is observed. The insulator to metal transition temperature exponentially increases with pressure and the distinct peak in the resistivity that is observed at 1.0 GPa almost vanishes for P > 7.0 GPa. A modification in the orbital occupation of the e(g) electron between 3d(x(2)-y(2)) and 3d(z(2)-r(2)) states, as proposed earlier, leading to a ferromagnetic double-exchange phenomenon, can qualitatively account for our data.

Characterization of a cellular retinol-binding protein from lamprey, Lethenteron japonicum

Lampreys are ancestral representatives of vertebrates known as jawless fish. The Japanese lamprey, Lethenteron japonicum, is a parasitic member of the lampreys known to store large amounts of vitamin A within its body. How this storage is achieved, however, is wholly unknown. Within the body, the absorption, transfer and metabolism of vitamin A are regulated by a family of proteins called retinoid-binding proteins. Here we have cloned a cDNA for cellular retinol-binding protein (CRBP) from the Japanese lamprey, and phylogenetic analysis suggests that lamprey CRBP is an ancestor of both CRBP I and II. The lamprey CRBP protein was expressed in bacteria and purified. Binding of the lamprey CRBP to retinol (Kd of 13.2 nM) was identified by fluorimetric titration. However, results obtained with the protein fluorescence quenching technique indicated that lamprey CRBP does not bind to retinal. Northern blot analysis showed that lamprey CRBP mRNA was ubiquitously expressed, although expression was most abundant in the intestine. Together, these results suggest that lamprey CRBP has an important role in absorbing vitamin A from the blood of host animals.

Transhiatal jejunal interposition preserving the whole stomach and vagal trunk for a benign esophageal stricture in a male adolescent: report of a case

Benign esophageal strictures are generally treated with medication and balloon dilation; however, when repeated dilations fail, surgery is the only option. When performing surgery for benign esophageal stricture in young patients, it is important to consider not only the surgical stress and likelihood of complications but also digestive function after reconstruction, the durability of the reconstruction, and the potential for cancerous change in the reconstructed organs. We describe how we treated a 14-year-old boy with benign esophageal stricture by performing transhiatal esophagectomy assisted by mediastinoscopy, preserving the whole stomach and vagus nerve, and interposing pedicled jejunum between the cervical esophagus and stomach through a posterior mediastinal route, with good long-term results.

Tumour suppressive microRNA-874 regulates novel cancer networks in maxillary sinus squamous cell carcinoma

BACKGROUND

On the basis of the microRNA (miRNA) expression signature of maxillary sinus squamous cell carcinoma (MSSCC), we found that miR-874 was significantly reduced in cancer cells. We focused on the functional significance of miR-874 in cancer cells and identification of miR-874-regulated novel cancer networks in MSSCC.

METHODS

We used PCR-based methods to investigate the downregulated miRNAs in clinical specimens of MSSCC. Our signature analyses identified 23 miRNAs that were significantly reduced in cancer cells, such as miR-874, miR-133a, miR-375, miR-204, and miR-1. We focused on miR-874 as the most downregulated novel miRNA in our analysis.

RESULTS

We found potential tumour suppressive functions such as inhibition of cancer cell proliferation and invasion. A molecular target search of miR-874 revealed that PPP1CA was directly regulated by miR-874. Overexpression of PPP1CA was observed in MSSCC clinical specimens. Silencing of the PPP1CA gene significantly inhibited cancer cell proliferation and invasion.

CONCLUSION

The downregulation of miR-874 was a frequent event in MSSCC, which suggests that miR-874 functions as a tumour suppressive miRNA, directly regulating PPP1CA that has a potential role of an oncogene. The identification of novel miR-874-regulated cancer pathways could provide new insights into potential molecular mechanisms of MSSCC oncogenesis.