Multi-imaging platform for rhizosphere studies: Phosphorus and oxygen fluxes.

Rhizosphere is a soil volume of high spatio-temporal heterogeneity and intensive plant-soil-microbial interactions, for which visualization and process quantification is of highest scientific and applied relevance, but still very challenging. A novel methodology for quick assessment of two-dimensional distribution of available phosphorus (P) in rhizosphere was suggested, tested, and development up to the application platform. Available P was firstly trapped by an in-situ diffusive gradients in thin-films (DGT) sampler with precipitated zirconia as the binding gel, and subsequently, the loaded gel was analyzed with an optimized colorimetric imaging densitometry (CID). The imaging platform was established linking: i) DGT, ii) planar optode, and iii) soil zymography techniques to simultaneously determine available P, oxygen, and acid phosphatase in rhizosphere at sub-millimeter spatial scales. The DGT identified available P level in rice rhizosphere were spatially overlapping to the localized redox hotspots and phosphatase activity. The spatial relationship between available P and acid phosphatase activity was dependent on root development. The root radial oxygen loss (ROL) remained active during the experimental observations (2-3 days), while a flux of available P of 10 pg cm-2 s-1 was visualized within 2-3 mm of roots, confirming the correlative response of rice roots to oxygen secretion and P uptake. Summarizing, the established imaging platform is suitable to capture spatial heterogeneity and temporal dynamics of root activities, nutrient bioavailability, ROL and enzyme activities in rhizosphere.

[Effects of seasonal temperature variation on nitrogen removal from a tidal flow constructed wetland system with CANON process]. / 季节性温度变化对CANON型潮汐流人工湿地脱氮的影响.

We investigated the effects of seasonal temperature variation on the treatment perfor-mance and underlying mechanisms of nitrogen transformation in a tidal flow constructed wetland (TFCW) with the complete autotrophic nitrogen removal over nitrite (CANON) process. Different temperatures resulted in periodical variations in nitrogen transformation pathways and removal performance of the TFCW with CANON process, which was mainly due to the changes of dominant bacterial communities for nitrogen removal in the system. When temperature was higher than 20.0 ℃, nitrogen transformation and associated microbial characteristics in the TFCW were significantly affected, and the CANON process remained to be the principal pathway for nitrogen removal. The abundance and activity of anammox bacteria experienced different degrees of reduction when temperature dropped below 20.0 ℃. At the temperature of 9.3-20.0 ℃, the proliferation and increased activities of nitrite oxidizing bacteria (NOB) made the nitrification/denitrification process instead of the CANON process became the primary total nitrogen (TN) removal route in the TFCW, and the TN removal efficiency of the system declined to 34.8%±13.0%. Under the temperature range of 2.2-9.0 ℃, anammox bacteria, which was inhibited at the low temperatures, presented competitive advantage in comparison with NOB and denitrifiers, resulting that nitrogen removal in the TFCW relied on the CANON process again. Correspondingly, nitrogen removal rate of the system was 54.8%±4.8%. This study was conductive to the optimization of the TFCW with CANON process, as well as its engineering application.

Effects of sulfated modification on the physicochemical properties and biological activities of ß-glucans from Qingke (Tibetan hulless barley).

In this study, the reaction conditions of sulfur trioxide-pyridine (SO3-Pyr) method for the modification of Qingke ß-glucans (THB) were optimized by response surface methodology, and effects of different degrees of substitution (low, medium, and high) on the physicochemical properties, antioxidant activities, and in vitro hypolipidemic activities of THB were investigated. The optimal reaction conditions to obtain the high degree of substitution of sulfated ß-glucans were as follows: ratio of SO3-Pyr to THB of 16.88 g/g, reaction time of 2.03 h, and reaction temperature of 57.54 °C. Results showed that sulfated modification significantly affected the water solubilities, apparent viscosities, molecular weights, and molar ratios of constituent monosaccharides of THB. Besides, the sulfated THB exhibited much better antioxidant activities (DPPH and nitric oxide radical scavenging activities, and reducing powers), in vitro binding properties (fat, cholesterol, and bile-acid binding capacities), and pancreatic lipase inhibition activities than that of THB. Indeed, the sulfated THB with higher degree of substitution has stronger antioxidant activities and in vitro hypolipidemic activities. Results suggested that the sulfated modification could be an efficient approach for the improvement of functional properties of THB, and sulfated THB could be further explored as functional food ingredients for industrial applications.

Extraction Optimization, Structural Characterization, and Antioxidant Activities of Polysaccharides from Cassia Seed (Cassia obtusifolia).

In order to explore Cassia seed polysaccharides (CSPs) as natural antioxidants for application in the functional-food industry, microwave-assisted extraction (MAE) was optimized for the extraction of CSPs by using a response surface methodology. Furthermore, the chemical structures and antioxidant activities of CSPs extracted by MAE and hot water extraction were investigated and compared. The maximum extraction yield of CSPs extracted by MAE (8.02 ± 0.19%) was obtained at the optimized extraction parameters as follows: microwave power (415 W), extraction time (7.0 min), and ratio of water to raw material (51 mL/g). Additionally, the contents of the uronic acids, molecular weight, ratio of constituent monosaccharides, intrinsic viscosities, and degrees of esterification of CSPs were significantly affected by the MAE method. Moreover, CSPs exhibited remarkable 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ABTS, 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl DPPH, nitric oxide, and hydroxyl radical scavenging activities as well as reducing power. The high antioxidant activities observed in CSPs extracted by MAE could be partially attributed to its low molecular weights and high content of unmethylated galacturonic acid. Results indicate that the MAE method could be an efficient technique for the extraction of CSPs with high antioxidant activity, and CSPs could be further explored as functional food ingredients.

Physicochemical characteristics and antioxidant activities of non-starch polysaccharides from different kiwifruits.

Non-starch polysaccharides are considered the main bioactive ingredients in kiwifruits. In order to well understand the chemical structures and antioxidant activities of non-starch polysaccharides from different varieties of kiwifruits (KPSs), the physicochemical characteristics and antioxidant activities of KPSs extracted by hot water extraction from Actinidia deliciosa cv. Hayward, A. chinensis cv. Hort16A, A. chinensis cv. Jinshi, A. chinensis cv. Hongshi, A. polygama, A. macrosperma, and A. arguta were investigated and compared. Results showed that extraction yields and contents of total uronic acids in KPSs ranged from 2.60% to 5.52%, and from 35.07% to 42.20%, respectively. Molecular weights and intrinsic viscosities of KPSs ranged from 1.405 × 105 to 1.620 × 106 Da, and from 0.34 dL/g to 1.24 dL/g, respectively. The dominant constituent monosaccharides of KPSs were galacturonic acid, arabinose, and galactose. Furthermore, KPSs from kiwifruits, especially KPSs extracted from A. arguta, exerted remarkable 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid and nitric oxide radical scavenging activities, which might be partially attributed to their high content of unmethylated galacturonic acids. Results are helpful for better understanding of the chemical structures and antioxidant activities of KPSs, and KPSs had potential to be further explored as natural antioxidants for the application in the functional food industry.

Implication of lncRNAs in pathogenesis of esophageal cancer.

Long non-coding RNAs (lncRNAs), transcripts as longer than 200 nt in length with a great number of varieties in human genomics, play important roles in the regulation of genetics and epigenetics including gene transcription and post-transcription. Increasing evidence have demonstrated the upregulation of lncRNAs in tumorigenesis and metastasis of esophageal cancer (EC), a type of malignant tumors particularly in Asia. In this review, we briefly discuss the profiles and functions of lncRNAs involved in the progression of EC, which may provide a new approach to improve EC diagnosis and treatment.

Upregulation of the long noncoding RNA PCAT-1 correlates with advanced clinical stage and poor prognosis in esophageal squamous carcinoma.

Recent studies reveal that long noncoding RNAs (lncRNAs) play critical regulatory roles in cancer biology. Prostate cancer-associated ncRNA transcript 1 (PCAT-1) is one of the lncRNAs involved in cell apoptosis and proliferation of prostate cancer. This study aimed to assess the potential role of PCAT-1 specifically in the pathogenesis of esophageal squamous cell carcinoma (ESCC). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression level of PCAT-1 in matched cancerous tissues and adjacent noncancerous tissues from 130 patients with ESCC, 34 patients with non-small cell lung cancer (NSCLC), and 30 patients with gastric carcinoma (GC). The correlation of PCAT-1 with clinicopathological features and prognosis were also analyzed. The expression of PCAT-1 was significantly higher in human ESCC compared with the adjacent noncancerous tissues (70.8%, p < 0.01), and the high level of PCAT-1 expression was significantly correlated with invasion of the tumor (p = 0.024), advanced clinical stage (p = 0.003), lymph node metastasis (p = 0.032), and poor prognosis. However, PCAT-1 mRNA expression had no significant difference between paired primary cancerous tissues and the adjacent noncancerous tissues in 34 cases of NSCLC (p = 0.293) and 30 cases of GC (p = 0.125). High expression of PCAT-1 was specifically correlated with invasion of cancer tissues, metastasis of lymph node, and advanced tumor stage of ESCC. High expression of PCAT-1 might reflect poor prognosis of ESCC and indicate a potential diagnostic target in ESCC patients. Adjuvant therapy targeting PCAT-1 molecule might be effective in treatment of ESCC.

Comparison of long non­coding RNAs, microRNAs and messenger RNAs involved in initiation and progression of esophageal squamous cell carcinoma.

Traditionally, cancer research has focused on protein­coding genes, which are considered the principal effectors and regulators of tumorigenesis. Non­coding RNAs, in particular microRNAs (miRNAs) and long non­coding RNAs (lncRNAs), have been widely reported to be important in the regulation of tumorigenesis and cancer development. However, to the best of our knowledge, investigation of the expression profiles of lncRNAs and a comparison of the involvement of lncRNAs, miRNAs and messenger RNAs (mRNAs) in esophageal tumorigenesis and development have not previously been performed. In the current study, intrinsic associations among the expression profiles of lncRNAs, miRNAs and mRNAs from normal esophageal tissues and those from cancer tissues were investigated. Oligonucleotide microarrays were used to detect the expression profiles of the three types of RNA in the canceration processes of human esophageal squamous cell carcinoma (ESCC) tissues. It was demonstrated that the different RNAs exhibit associated patterns of expression among normal esophageal epithelium, low­grade intraepithelial neoplasia (LGIN), high­grade intraepithelial neoplasia (HGIN), and carcinoma tissues, particularly in the critical period of canceration (HGIN to ESCC). Furthermore, the results indicated a high level of similarity in the potential function of lncRNAs, miRNAs and mRNAs in the processes of ESCC development. In the current study, a first generation atlas of lncRNA profiling and its association with miRNAs and mRNAs in the canceration processes of ESCC were presented.

Long noncoding RNA SPRY4-IT1 is upregulated in esophageal squamous cell carcinoma and associated with poor prognosis.

LncRNA SPRY4-IT1 has been shown to promote the progression of melanoma. However, the role of lncRNA SPRY4-IT1 in human esophageal squamous cell carcinoma (ESCC) remains unclear. The purpose of this study is to investigate the clinical significance and biological functions of SPRY4-IT1 in ESCC. The expression levels of lncRNA SPRY4-IT in 92 ESCC patients and 8 ESCC cell lines were evaluated by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The prognostic significance was evaluated using Kaplan-Meier and Cox regression analyses. Small interfering RNA (siRNA) was used to suppress SPRY4-IT1 expression in ESCC cell lines. Both in vitro and in vivo assays were performed to further explore its role in tumor progression. SPRY4-IT1 levels were significantly higher in ESCC tissues and cells than in corresponding adjacent noncancerous tissues and nontumorigenic esophageal epithelial cells, and the ESCC patients with higher SPRY4-IT1 expression had an advanced clinical stage and poorer prognosis than those with lower SPRY4-IT1 expression. The multivariate analysis revealed that SPRY4-IT1 expression level is an independent prognostic factor in ESCC patients. In vitro assays demonstrated that knockdown of SPRY4-IT1 reduced cell proliferation, invasiveness, and migration. In vivo assays demonstrated that knockdown of SPRY4-IT1 decreases cell growth. SPRY4-IT1 is a novel molecule involved in ESCC progression, which may provide a potential prognostic biomarker and a potential target for therapeutic intervention.

Upregulation of the long non-coding RNA PlncRNA-1 promotes esophageal squamous carcinoma cell proliferation and correlates with advanced clinical stage.

BACKGROUND: Recent studies revealed that long noncoding RNAs (lncRNAs) play critical regulatory roles in cancer biology. PlncRNA-1 is one of lncRNAs that is associated with cell apoptosis and proliferation of prostate cancer. AIM: This study aimed to assess the potential role of PlncRNA-1 in the pathogenesis of esophageal squamous cell carcinoma (ESCC). MATERIALS AND METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression level of PlncRNA-1 in 73 pairs of ESCC and their matched normal tissues. The correlation of PlncRNA-1 with clinicopathological features and clinical stages was also analyzed. Cancer cell proliferation and apoptosis were assessed following knock-down of PlncRNA-1 by MTT, colony formation assay, and flow cytometry. RESULTS: The expression of PlncRNA-1 was significantly higher in human ESCC compared with the adjacent noncancerous tissues (69.8 %, p < 0.05), and the high level of PlncRNA-1 expression was significantly correlated with advanced clinical stage (p < 0.01) and lymph node metastasis (p < 0.05). Furthermore, knockdown of PlncRNA-1 reduced cell proliferation and increased the apoptosis in vitro. CONCLUSIONS: PlncRNA-1 plays an important role in ESCC cell proliferation. Overexpression of PlncRNA-1 is correlated with advanced tumor stage and lymph node metastasis, and may serve as a potential prognostic marker and therapeutic target for ESCC.

Upregulation of the long non-coding RNA HOTAIR promotes esophageal squamous cell carcinoma metastasis and poor prognosis.

Recent studies of the individual functionalities of long non-coding RNAs (lncRNAs) in the development and progression of cancer have suggested that HOX transcript antisense RNA (HOTAIR) is capable of reprogramming chromatin organization and promoting cancer cell metastasis. In order to ascertain the expression pattern of the lncRNA HOTAIR and assess its biological role in the development and progression of esophageal squamous cell carcinoma (ESCC), HOTAIR expression in ESCC tissues and adjacent noncancerous tissues were collected from 78 patients and measured by real-time reverse transcription-polymerase chain reaction (RT-PCR). HOTAIR correlation with clinicopathological features and prognosis was also analyzed. Suppression of HOTAIR using siRNA treatment was performed in order to explore its role in tumor progression. Notably elevated HOTAIR expression levels were observed in cancerous tissues compared to adjacent noncancerous tissues (96%, P < 0.01), showing a high correlation with cancer metastasis (P < 0.01), elevated TNM (2009) stage classification (P < 0.01), and lowered overall survival rates (P = 0.003). Multivariate analysis revealed that HOTAIR expression (P = 0.003) is also an independent prognostic factor for comparison of TNM stage (P = 0.024) and lymph node metastasis (P = 0.010). Furthermore, in vitro assays of the ESCC cell line KYSE30 demonstrated that knockdown of HOTAIR reduced cell invasiveness and migration while increasing the response of cells to apoptosis. Thus, HOTAIR is a novel molecule involved in both ESCC progression and prognosis. Full elucidation of HOTAIR functionality relevant to ESCC may open avenues for the use of lncRNAs in identification of novel drug targets and therapies for ESCC and other prevalent cancers.

Association of ß-catenin, Wnt1, Smad4, Hoxa9, and Bmi-1 with the prognosis of esophageal squamous cell carcinoma.

In our previous study, Human Signal Transduction in Cancer Gene Array was used in 12 fresh tumor samples to detect the gene expression profiles in the esophageal squamous cell carcinoma (ESCC) tissues matched adjacent non-cancerous samples. Among genes up-regulated at least twofold, ß-catenin, Wnt1, Smad4, Hoxa9, and Bmi-1 were found. So subsequently, the aim of this study was to investigate the prognosis and clinicopathologic roles of ß-catenin, Wnt1, Smad4, Hoxa9, and Bmi-1 in ESCC tissue. The mRNA and protein expression levels of ß-catenin, Wnt1, Smad4, Hoxa9, and Bmi-1 genes in 70 ESCC and adjacent non-cancerous paraffin-embedded samples were determined by Real-Time Quantitative PCR (RT-PCR) and immunohistochemical staining. The mRNA expression level of ß-catenin, Wnt1, Smad4, Hoxa9, and Bmi-1 in ESCC was significantly higher than that in the adjacent non-cancerous tissues (0.0821 ± 0.0416 vs. 0.0185 ± 0.0201, P = 0.0000; 1.9934 ± 1.9888 vs. 0.8863 ± 0.665, P = 0.0184; 0.0298 ± 0.0215 vs. 0.0189 ± 0.0187, P = 0.0017; 2.098 ± 0.091 vs. 1.016 ± 0.078, P = 0.0000; 2.181 ± 2.158 vs. 0.931 ± 0.894, P = 0.0152; respectively), and the protein expression level of determined genes was also significantly higher than that in the adjacent non-cancerous tissues (0.2835 ± 0.0844 vs. 0.2352 ± 0.0670, P = 0.0003; 0.3830 ± 0.0947 vs. 0.2721 ± 0.1474, P = 0.0000; 0.2637 ± 0.0348 vs. 0.2042 ± 0.0180, P = 0.0000; 0.2058 ± 0.0316 vs. 0.1218 ± 0.0518, P = 0.0000; 0.2736 ± 0.0834 vs. 0.2251 ± 0.0571, P = 0.0001; respectively). Then, the overexpression of mRNA and protein levels of ß-catenin, Wnt1 and Bmi-1 was aggressively associated with lymph node metastasis, advanced pathological stage, and prognosis of the patients with ESCC (P < 0.05). The up-expression of Hoxa9 mRNA and protein was also aggressively associated with lymph node metastasis and advanced pathological stage (P < 0.05); however, the overexpression of Hoxa9 protein was not associated with the prognosis (P > 0.05). Meanwhile, the hypo-expression of Smad4 mRNA was aggressively associated with advanced pathological stage and prognosis of the patients with ESCC (P < 0.05); however, the hypo-expression of Smad4 protein was neutral to the prognosis and lymph node metastasis (P > 0.05). ß-catenin, Wnt1, Smad4, Hoxa9, and Bmi-1 protein expression analysis showed that the positive outcomes of the combined detection of Wnt1 and ß-catenin expression or Wnt1, ß-catenin and Bmi-1 expression were significantly worse than those of a single target protein expression (P < 0.05). Meantime, the prognosis of the combined positive expression of Wnt1, ß-catenin, and Bmi-1 was poorer than that in the combined positive expression of Wnt1 and ß-catenin (P < 0.05). The prognosis of ESCC patients with the overexpression of Wnt1/ß-catenin and Bmi-1 was relatively poor, and the level of Wnt1/ß-catenin and Bmi-1 was conversely correlated with advanced pathological stage and lymph node metastasis. The expression level of Smad4 and Hoxa9 mRNA was also associated with the prognosis of the patients with ESCC, pathological stage, and lymph node metastasis; however, they might not be the independent prognostic factor.