Prognostic significance and relationship of SMAD3 phospho-isoforms and VEGFR-1 in gastric cancer: A clinicopathological study.

BACKGROUND: The TGF-ß/SMAD3 and VEGFR-1 signaling pathways play important roles in gastric cancer metastasis. SMAD3 phosphorylation is a crucial prognostic marker in gastric cancer. AIM: To determine the prognostic value and relationship of SMAD3 phospho-isoforms and VEGFR-1 in gastric cancer. METHODS: This was a single-center observational study which enrolled 98 gastric cancer patients and 82 adjacent normal gastric tissues from patients aged 32-84 years (median age 65) between July 2006 and April 2007. Patients were followed up until death or the study ended (median follow-up duration of 28.5 mo). The samples were used to generate tissue microarrays (TMAs) for immunohistochemical (IHC) staining. The expressions of TGF-ß1, pSMAD3C(S423/425), pSMAD3L(S204), and VEGFR-1 in gastric cancer (GC) tumor tissue and normal tissue were measured by IHC staining using TMAs obtained from 98 GC patients. Prognosis and survival information of the patients was recorded by Outdo Biotech from May 2007 to July 2015. The relationship between TGF-ß1, pSMAD3C(S423/425), pSMAD3L(S204), and VEGFR-1 protein expression levels was analyzed using Pearson's correlation coefficient. The relationship between protein expression levels and clinicopathological parameters was analyzed using the Chi-squared test. A survival curve was generated using the Kaplan-Meier survival analysis. RESULTS: TGFß-1 and VEGFR-1 expression was significantly upregulated in gastric cancer tissue compared to adjacent non-cancerous tissue. The positive expression of phosphorylated isoforms of Smad3 varied depending on the phosphorylation site [pSMAD3C(S423/425): 51.0% and pSMAD3L(S204): 31.6%]. High expression of pSMAD3L(S204) was significantly correlated with larger tumors (P = 0.038) and later N stages (P = 0.035). Additionally, high expression of VEGFR-1 was closely correlated with tumor size (P = 0.015) and pathological grading (P = 0.013). High expression of both pSMAD3L(S204) and VEGFR-1 was associated with unfavorable outcomes in terms of overall survival (OS). Multivariate analysis indicated that high expression of pSMAD3L(S204) and VEGFR-1 were independent risk factors for prognosis in GC patients. VEGFR-1 protein expression was correlated with TGF-ß1 (r = 0.220, P = 0.029), pSMAD3C(S423/425) (r = 0.302, P = 0.002), and pSMAD3L(S204) (r = 0.201, P = 0.047), respectively. Simultaneous overexpression of pSMAD3L(S204) and VEGFR-1 was associated with poor OS in gastric cancer patients. CONCLUSION: Co-upregulation of pSMAD3L(S204) and VEGFR-1 can serve as a predictive marker for poor gastric cancer prognosis, and pSMAD3L(204) may be involved in enhanced gastric cancer metastasis in a VEGFR-1-dependent manner.

Control of Mosses on Water Flux in an Alpine Shrub Site on the Qilian Mountains, Northwest China.

Mosses are an important component of the alpine shrub, but little is known about their contribution to ecosystem water and energy exchange, especially potential opportunities for alpine shrub expansion under a warming climate. We studied the role of mosses in alpine shrub evapotranspiration by conducting herb and moss removal experiments with different Potentilla fruticosa L. shrub coverage in the Qilian Mountains, Northwest China. The understory evapotranspiration was measured using lysimeters in different shrub coverage (dense shrub cover, medium shrub cover, and thin shrub cover) during the growing season of 2012. The understory evapotranspiration is about 1.61 mm per day in the control treatment (intact moss and herbs) during the growing season, and the evapotranspiration rates differed significantly between canopy covers. We found a 22% increase in evapotranspiration losses after removing the moss layer compared to the control treatment lysimeter with an intact moss layer in the shrub site. This suggests that most of the understory evaporation originated from the organic layer underlying the moss layer. Given this study's large moss evaporation rates, understory contributions cannot be ignored when interpreting eddy covariance data for the whole alpine ecosystem. Our results show that mosses may exert strong controls on understory water fluxes in alpine shrub meadow ecosystems and suggest that changes in moss cover may have significant consequences for season frozen soil thaw.

Characteristics of dissolved organic carbon and nitrogen in precipitation in the northern Tibetan Plateau.

Dissolved organic carbon (DOC) and nitrogen (N) play essential roles in global C and N cycles. To address the possible role of DOC and N in precipitation and enrich the related global database, the characteristics of DOC and N in precipitation were investigated in a typical remote permafrost region (upper Heihe River Basin) of the northern Tibetan Plateau (TP) from February 2019 to March 2020. The results demonstrated that the average DOC and total dissolved N (TDN) concentrations in the precipitation were 1.41 ± 1.09 µg mL-1 and 0.84 ± 0.48 µg mL-1, respectively, with relatively lower concentrations in the summer. The annual DOC and TDN fluxes were estimated to be 6.42 kg ha-1 yr-1 and 3.39 kg ha-1 yr-1, respectively, indicating that precipitation was a significant factor in C and N deposition. The light-absorbing properties of precipitation DOC from the SUVA254 and spectral slope revealed that precipitation DOC containing more aromatic components and lower molecular weights mostly was present during the summer; the mass cross-section (at the wavelength of 365 nm) ranged 0.26-1.84 m2 g-1, suggesting the potential impact of DOC on climatic forcing in the area. The principal component analysis combined with air mass backward trajectories indicated that the air masses from west Siberia, Central Asia, and northwestern China most significantly influenced the precipitation C and N in the study area. The WRF-Chem simulations and aerosol vertical distributions further illustrated the air mass transport pathways, demonstrating that dust and anthropogenic emissions could be transported over the studied area by westerlies and monsoonal winds. In the study basin, the precipitation deposition of DOC and N contributed largely to the riverine DOC and N exportation during the summer and had potential ecological effects. These results highlight the importance of DOC and N deposition from precipitation in the northern TP.

Long non-coding RNA LINC00488 facilitates thyroid cancer cell progression through miR-376a-3p/PON2.

OBJECTIVE: Long non-coding RNAs (lncRNAs) recently have been identified as influential indicators in a variety of malignancies. The aim of the present study was to identify a functional lncRNA LINC00488 and its effects on thyroid cancer in the view of cell proliferation and apoptosis. METHODS: In order to evaluate the effects of LINC00488 on the cellular process of thyroid cancer, we performed a series of in vitro experiments, including cell counting kit-8 (CCK-8) assay, EdU (5-ethynyl-2'-deoxyuridine) assay, flow cytometry, transwell chamber assay, Western blot and RT-qPCR. The target gene of LINC00488 was then identified by bioinformatics analysis (DIANA and TargetScan). Finally, a series of rescue experiments was conducted to validate the effect of LINC00488 and its target genes on proliferation, migration, invasion and apoptosis of thyroid cancer. RESULTS: Our findings revealed that LINC00488 was highly expressed in thyroid cancer cell lines (BCPAP, BHP5-16, TPC-1 and CGTH-W3) and promoted the proliferation, migration and invasion, while inhibited the apoptosis of thyroid cancer cells (BCPAP and TPC-1). The results of bioinformatics analysis and dual luciferase reporter gene assay showed that LINC00488 could directly bind to miR-376a-3p and down-regulated the expression level of miR-376a-3p. In addition, Paraoxonase-2 (PON2) was a target gene of miR-376a-3p and negatively regulated by miR-376a-3p. Rescue experiment indicated that LINC00488 might enhance PON2 expression by sponging miR-376a-3p in thyroid cancer. CONCLUSION: Taken together, our study revealed that lncRNA LINC00488 acted as an oncogenic gene in the progression of thyroid cancer via regulating miR-376a-3p/PON2 axis, which indicated that LINC00488-miR-376a-3p-PON2 axis could serve as novel biomarkers or potential targets for the treatment of thyroid cancer.

Riverine dissolved organic carbon and its optical properties in a permafrost region of the Upper Heihe River basin in the Northern Tibetan Plateau.

Riverine dissolved organic carbon (DOC) and its optical properties were investigated in two sub-river basins (Yeniugou and Hulugou river) of the Upper Heihe river basin in the northern Tibetan Plateau. The results showed that DOC concentrations ranged from 0.25 to 12.2 and 0.18-1.04 mg L-1 for Yeniugou and Hulugou river basin with an average of 0.82 and 0.33 mg L-1, respectively. Export of DOC from the studied river (YNG: ~0.86 Gg C yr-1) was lesser compared with other large river in the Tibetan Plateau and Arctic regions because of the small drainage area and lower DOC concentrations. There exhibited significant seasonality for DOC in Yeniugou river basin with higher values observed during late spring and summer; however, no such distinct trend was observed for DOC in the studied rivers of Hulugou river basin. In contrast, total dissolved nitrogen showed a slightly lower value during the summer season. A strong relationship was determined between DOC concentrations and spectral UV absorbance at 254 nm (SUVA254), absorption coefficients and spectral slope for both sub-river basins, attributing that the riverine DOM in the northern Tibetan Plateau has a remarkably high content of aromatic compounds in late spring and summer. Considering the less snow cover percentage, this study highlights the potential impacts of permafrost thaw on the riverine DOC and its characteristics in the permafrost region under climate change.

Downregulation of miR­186 promotes the proliferation and drug resistance of glioblastoma cells by targeting Twist1.

Temozolomide (TMZ) is widely used as a chemotherapeutic agent in the treatment of glioma; however, the development of drug resistance remains a major obstacle in the effective treatment of glioblastoma. Increasing evidence has indicated that microRNAs (miRs) are involved in the drug resistance of glioma; however, the role of miR­186­5p in the TMZ resistance of glioblastoma remains unknown. In the present study, the role of miR­186­5p in the resistance of glioblastoma to TMZ was investigated. mRNA and protein expression levels were detected via reverse transcription­quantitative PCR and western blot analysis, respectively. It was determined that miR­186­5p was significantly downregulated in glioblastoma tissues and cell lines. Additionally, the expression of miR­186­5p was decreased, whereas that of Twist1 was upregulated during the development of drug resistance in glioma cells. The introduction of miR­186 into glioblastoma cells via transfection decreased the proliferation and TMZ resistance of glioblastoma cells, as determined via 5­ethynyl­2'­deoxyuridine and Cell Counting Kit­8 assays, whereas the inhibition of miR­186­5p induced opposing effects. Furthermore, luciferase reporter and expression rescue assays revealed that miR­186­5p bound to the 3'­untranslated region of Twist­related protein 1 (Twist1). In conclusion, the present study demonstrated that downregulation of miR­186­5p may contribute to the proliferation and drug resistance of glioblastoma cells via the regulation of Twist1 expression. These results suggested that miR­186­5p may be a novel therapeutic target in the treatment of glioblastoma.

Publisher Correction: Regional disparities in warm season rainfall changes over arid eastern-central Asia.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Regional disparities in warm season rainfall changes over arid eastern-central Asia.

Multiple studies have reported a shift in the trend of warm season rainfall over arid eastern-central Asia (AECA) around the turn of the new century, from increasing over the second half of the twentieth century to decreasing during the early years of the twenty-first. Here, a closer look based on multiple precipitation datasets reveals important regional disparities in these changes. Warm-season rainfall increased over both basin areas and mountain ranges during 1961-1998 due to enhanced moisture flux convergence associated with changes in the large-scale circulation and increases in atmospheric moisture content. Despite a significant decrease in warm-season precipitation over the high mountain ranges after the year 1998, warm season rainfall has remained large over low-lying basin areas. This discrepancy, which is also reflected in changes in river flow, soil moisture, and vegetation, primarily results from disparate responses to enhanced warming in the mountain and basin areas of AECA. In addition to changes in the prevailing circulation and moisture transport patterns, the decrease in precipitation over the mountains has occurred mainly because increases in local water vapor saturation capacity (which scales with temperature) have outpaced the available moisture supply, reducing relative humidity and suppressing precipitation. By contrast, rainfall over basin areas has been maintained by accelerated moisture recycling driven by rapid glacier retreat, snow melt, and irrigation expansion. This trend is unsustainable and is likely to reverse as these cryospheric buffers disappear, with potentially catastrophic implications for local agriculture and ecology.

Nerve growth factor and its receptors on onset and diagnosis of ovarian cancer.

The effect of nerve growth factor (NGF) and its receptors on the onset and diagnosis of ovarian cancer was investigated. A total of 35 patients with ovarian tumor admitted in the First Affiliated Hospital of Nanchang University from July 2014 to July 2015 were selected as study subjects and were divided into an observation group (including 21 patients with benign ovarian tumor, and 14 patients with malignant ovarian tumor), and a control group (21 healthy women). The quantity of expression of mRNA in NGF and its receptors (TrkA and p75NTR) was detected using fluorescent quantitative PCR. The protein expression of NGF, TrkA and p75NTR in different study samples was detected using ELISA and western blot analysis. The location of expression was determined using immunohistochemistry. The positive cell rate in different samples was analyzed. Compared with healthy women, the quantity of expression of mRNA in NGF, TrkA and p75NTR in patients with ovarian cancer was increased significantly. The results of ELISA showed that the quantity of protein expression of NGF, TrkA and p75NTR was 0.98±0.12, 1.23±0.14 and 0.76±0.07 µg/l in healthy women, and was 3.21±0.16, 5.28±0.25 and 2.97±0.13 µg/l, respectively, in women with ovarian tumor, and there were statistically significant differences (P<0.05), and the level of expression in patients with malignant ovarian tumor was significantly higher than that in patients with benign ovarian cancer. Western blot analysis also showed that the quantity of expression of NGF, TrkA and p75NTR gene in women with ovarian cancer was significantly higher than that in healthy women. Immunohistochemical results showed that the number of positive cells of NGF, TrkA and p75NTR gene in the tissue of patients with ovarian cancer (89.5, 93.4 and 82.5%, respectively) was significantly higher than those in healthy ovarian tissue (9.4, 10.3 and 7.9%, respectively). In conclusion, NGF and its receptor can contribute to the occurrence of ovarian cancer, and the onset condition of ovarian cancer can be diagnosed through the detection of high or low expression of NGF and its receptors.

Clinical significance and role of LKB1 in gastric cancer.

Liver kinase B1 (LKB1) functions as a tumor suppressor gene, and loss in the expression of LKB1 contributes to human carcinogenesis and tumor progression. The present study investigated the association between LKB1 and gastric cancer. SGC­7901 gastric cancer cell lines and 63 patients with gastric cancer were examined in the present study, and lentivirus transfection, reverse transription­quantitative polymerase chain reaction and flow cytometric analyses were performed. By examining the expression of LKB1 using immunohistochemical analyses, the present study found that the expression of LKB1 was reduced in the gastric cancer tissues, and restoration of the expression of LKB1 reduced tumor cell viability, migration rate and the expression of CD44, induced cell cycle arrest at the G2 phase of the cell cycle, and increased the sensitivity of the gastric cancer cells to anticancer drugs. LKB1 protein is a tumor­suppressor in gastric cancer and may be potentially be developed as a novel gene therapy target in the treatment of gastric cancer.

Large-scale study of long non-coding RNA functions based on structure and expression features.

Mammals and other complex organisms can transcribe an abundance of long non-coding RNAs (lncRNAs) that fulfill a wide variety of regulatory roles in many biological processes. These roles, including as scaffolds and as guides for protein-coding genes, mainly depend on the structure and expression level of lncRNAs. In this review, we focus on the current methods for analyzing lncRNA structure and expression, which is basic but necessary information for in-depth, large-scale analysis of lncRNA functions.

[Measurement and estimation of grassland evapotranspiration in a mountainous region at the upper reach of Heihe River basin, China].

Evapotranspiration (ET) is an important component of water cycle, but its measurement in high altitude mountainous region is quite difficult, inducing the insufficient understanding on the actual ET in high altitude mountainous region and the effects of ET on this region' s water cycle. In this paper, two small type weighing mini-lysimeters were applied to measure the daily ET in a piece of grassland in a high altitude mountainous region of the Heihe River basin from July 1st, 2009 to June 30th, 2010. Based on the measured data, the methods of FAO-56 Penman-Monteith (F-P-M), Priestley-Taylor (P-T), and Hargreaves-Samani (H-S) were employed to estimate the ET to analyze the applicability of the three methods for the mountainous region, and the pan coefficient at the measurement spots was discussed. During the measurement period, the total annual ET at the measurement spots was 439.9 mm, accounting for 96.5% of the precipitation in the same period, and the ET showed an obvious seasonal distribution, being 389. 3 mm in May-October, accounting for 88. 5% of the annual value. All the three methods could be well applied to estimate the summer ET but not the winter ET, and their applicability followed the sequence of P-T > F-P-M > H-S. At the measurement spots, the daily pan coefficient in summer was 0.7-0. 8, while that in winter was quite variable.

[Characteristics of stemflow for typical alpine shrubs in Qilian Mountain].

Taking the typical alpine shrubs Potentilla fruticosa, Salix cupularis, Hippophae rhamnoides, and Caragana jubata in Qilian Mountain as test objects, a field investigation from June 1 to October 31, 2010 was conducted on the variation characteristics of the shrub stemflow, and analyzed the affecting effects of rainfall intensity and canopy structure morphology. The stemflow generated when the rainfall in early period was 2.1 mm, with an average of 3.4%, 3.2%, 8.0%, and 4.2% of the gross rainfall for P. fruticosa, S. cupularis, H. rhamnoides, and C. jubata, respectively. There was a significant positive linear correlation between the stemflow and rainfall intensity. With increasing rainfall, the stemflow percentage showed a trend of increase-decrease-increase. Stemflow played an important role in supplying water to the shrub rhizosphere, and the average funneling ratio was 59, 30, 110, and 49 for P. fruticosa, S. cupularis, H. rhamnoides, and C. jubata, respectively. The stemflow percentage had a significant exponential relationship with the maximum rain intensity in 10 minutes (I10). When the I10 was more than 6.0 mm x h(-1), the stemflow of H. rhamnoides and C. jubata showed a persistently increasing trend, while that of P. fruticosa and S. cupularis tended to be stable. Canopy structure morphology had complicated effects on the stemflow. In the same rainfall intensities, the height and crown projection area of the shrubs were the important factors affecting the generation of stemflow.

[Observation on marrow-derived mesenchymal stem cells differentiating into functional cells in rabbit with smoke inhalation injury].

OBJECTIVE: To observe the homing and differentiation of marrow-derived mesenchymal stem cells (MSC) transplanted intravenously in smoke inhalation injured rabbits. METHODS: Thirty-two New Zealand big ear rabbits were divided into normal control group (NC), inhalation injury group (II), normal control + MSC treatment group (NM), and MSC treatment group (MT) according to the random number table, with 8 rabbits in each group. Rabbits in NC group were injected with 10 mL phosphate buffered saline (PBS) via ear marginal vein. Rabbits in NM group were injected with 10 mL PBS containing the third generation MSC labeled by BrdU (1 × 10(7) per 10 mL PBS) via ear marginal vein. Severe smoke inhalation injury model was reproduced in the other two groups, among them rabbits in II group were treated as rabbits in NC group, rabbits in MT group treated as rabbits in NM group. On the 7th and 28th day post treatment (PTD), lung tissue and trachea tissue were harvested from four groups for observation on injury with HE staining. Homing of MSC in injured tissue was observed with immunohistochemistry staining. The differentiation of MSC into functional cells was observed with immunohistochemical double staining of combining nuclear marker BrdU with lung (trachea) membrane-specific marker aquaporin-5 (AQP-5), alkaline phosphatase (AKP), CD34, and cytokeratin respectively. RESULTS: (1) MSC homing in lung and trachea tissue was observed in MT group on PTD 7, which was not observed in NM group. (2) AQP-5, AKP, and CD34 positive MSC were observed in lung tissue in MT group on PTD 28, while cytokeratin positive MSC was not observed in trachea tissue. No positively marked MSC was observed in NM group. (3) Injury in lung and trachea was less severe in MT group than in II group; and the proliferation of fibroblasts was less in MT group. CONCLUSIONS: Intravenous injection of MSC to rabbits with smoke inhalation injury can migrate to lung and trachea tissue at obviously inflammatory site, and differentiate into alveolar epithelial cells typeI and II, and pulmonary vascular endothelial cells, which may participate in the process of tissue repair in smoke inhalation injury.

[The effect of bone marrow mesenchymal stem cells engraftment on lung tissue at early stage of smoke inhalation injury in rabbits].

OBJECTIVE: To explore the effect of bone marrow mesenchymal stem cells (MSCs) engraftment on lung tissue at early stage of smoke inhalation injury in rabbits. METHODS: MSCs were proliferated by the method of whole marrow culture and identified by flow cytometry. Forty-eight rabbits were randomly divided into smoke inhalation group (S group) and MSCs group (M group) after reproduction of rabbit smoke inhalation injury model. 10 ml of phosphate buffer saline (PBS) containing 1×10(7)/ml MSCs was intravenously injected in M group, meanwhile 10 ml PBS was injected intravenously in S group. Eight rabbits were sacrificed at 2, 6 and 24 hours after intervention, and the lung tissue was harvested for morphological and pathological observation, and lung injury score was used to evaluate smoke inhalation injury. RESULTS: Cultured cells were confirmed to be MSCs with flow cytometry. Lung injury in rabbits of M group was less serious in morphology and histopathology than that in S group. Though there was no significance in lung injury score between M group and S group at 2 hours after injury (4.0±0.7 vs. 4.5±0.6, P>0.05), the lung injury scores in M group at 6 hours and 24 hours after injury were significantly lower than those in S group (6 hours: 6.1±0.9 vs. 8.2±0.9, 24 hours: 4.6±0.9 vs. 10.4±0.8, both P<0.01). CONCLUSION: Intravenous engraftment of MSCs could ameliorate lung injury induced by smoke inhalation, and improve lung injury score significantly.

Temporal variations of CO2 concentration near land surface and its response to meteorological variables in Heihe River Basin, northwest China.

Atmospheric CO2 concentration (CC) near land surface and meteorological variables have been measured at four sites, named Yeniugou (alpine meadow and permafrost), Xishui (mountainous forest), Linze (oasis edge) and Ejina (lower desert), respectively, in Heihe River Basin, northwest China. The results showed that, the half hourly CC at night was larger than in daytime, and the daily averaged CC was the largest in winter. The averaged CC of 932 d at the Linze was about 418 ppm, was about 366 ppm in the 762 d at the Ejina. In the same period from September 23 to November 9, 2004, the averaged CC was about 625, 334, 436 and 353 ppm, at Yeniugou, Xishui, Linze and Ejina, respectively. The linear relationship between daily averaged CC and air temperature T was negative, between CC and relative humidity (RH) was positive. The linear CC-atmospheric pressure (AP) relationship was negative at the Linze and Yeniugou, was positive at the Ejina. The relationship between CC and global radiation R was exponent, and soil temperature Ts was negative linear, and soil water content was complex. The correlation between CC and wind speed was not existent. Using meteorological variables together to simulate CC, could give good results.