Search

To study non-structural carbohydrate characteristics and nutrient utilization strategies of Pinus yunnanensis under continuous drought conditions, 2-year-old seedlings were planted in pots with appropriate water, light and moderate and severe drought treatments [(80 ± 5), (65 ± 5), (50 ± 5), and (35 ± 5)% of field water-holding capacity]. Non-structural carbohydrates, carbon (C), nitrogen (N), and phosphorus (P) concentrations were measured in each plant component. The results show that: (1) With increasing drought, non-structural carbohydrates gradually increased in leaves, stems, and coarse roots, while gradually decreased in fine roots; (2) C concentrations of all were relatively stable under different stress levels. Phosphorous utilization of each component increased under light and moderate drought conditions, while N and P utilization efficiency of each plant component decreased under severe drought. Growth was mainly restricted by N, first decreasing and then increasing with increased drought; (3) There was a correlation between the levels of non-structural carbohydrates and C, N, and P in each component. Changes in N concentration affected the interconversion between soluble sugar and starch, which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates; and, (4) Plasticity analysis showed that P. yunnanensis seedlings responded to drought mainly by altering starch concentration, the ratio of soluble sugar to starch in leaves and stems, and further by altering N and P utilization efficiencies. Overall, these results suggest that the physiological activities of all organs of P. yunnanensis seedlings are restricted under drought and that trade-offs exist between different physiological indicators and organs. Our findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in P. yunnanensis seedlings. [ABSTRACT FROM AUTHOR]

Summary: A new wood-inhabiting fungal species, Eichleriellaaculeobasidiata sp. nov, is described based on a combination of morphological features and molecular evidence. E.aculeobasidiata is characterised by a dimitic hyphal system with clamped generative hyphae, and narrowly ovoid to obconical, distinctly curved, hyaline, smooth, thin-walled basidiospores which contain oil droplets. Sequences of the ITS gene region of the studied samples were generated, and phylogenetic analyses were performed with maximum likelihood, maximum parsimony and Bayesian inference methods. The phylogenetic analysis showed that E.aculeobasidiata belonged to Eichleriella and formed a monophyletic lineage with strong support (100% BS, 100% BP, 1.00 BPP), and then grouped with a clade comprised of E. xinpingensis and E. tenuicula. [ABSTRACT FROM AUTHOR]

Background: Mitochondrial dynamics plays an important role in tumour progression. However, how these dynamics integrate tumour metabolism in hepatocellular carcinoma (HCC) metastasis is still unclear.Methods: The mitochondrial fusion protein mitofusin-1 (MFN1) expression and its prognostic value are detected in HCC. The effects and underlying mechanisms of MFN1 on HCC metastasis and metabolic reprogramming are analysed both in vitro and in vivo.Results: Mitochondrial dynamics, represented by constant fission and fusion, are found to be associated with HCC metastasis. High metastatic HCC displays excessive mitochondrial fission. Among genes involved in mitochondrial dynamics, MFN1 is identified as a leading downregulated candidate that is closely associated with HCC metastasis and poor prognosis. While promoting mitochondrial fusion, MFN1 inhibits cell proliferation, invasion and migration capacity both in vitro and in vivo. Mechanistically, disruption of mitochondrial dynamics by depletion of MFN1 triggers the epithelial-to-mesenchymal transition (EMT) of HCC. Moreover, MFN1 modulates HCC metastasis by metabolic shift from aerobic glycolysis to oxidative phosphorylation. Treatment with glycolytic inhibitor 2-Deoxy-D-glucose (2-DG) significantly suppresses the effects induced by depletion of MFN1.Conclusions: Our results reveal a critical involvement of mitochondrial dynamics in HCC metastasis via modulating glucose metabolic reprogramming. MFN1 may serve as a novel potential therapeutic target for HCC. [ABSTRACT FROM AUTHOR]

The goal of cancer eradication has been overshadowed despite the continuous improvement in research and generation of novel cancer therapeutic drugs. One of the undeniable existing problems is drug resistance due to which the paradigm of killing all cancer cells is ineffective. Tumor microenvironment plays a crucial role in inducing drug resistance besides cancer development and progression. Recently, many efforts have been devoted to understand the role of tumor microenvironment in cancer drug resistance as it provides the shelter, nutrition, and paracrine niche for cancer cells. Cancer-associated fibroblasts (CAFs), one major component of tumor microenvironment, reside in symbiotic relationship with cancer cells, supporting them to survive from cancer drugs. The present review summarizes the recent understandings in the role of CAFs in drug resistance in various tumors. Acknowledging the fact that drug resistance depends not only upon cancer cells but also upon the microenvironment niche could guide us to formulate novel cancer drugs and provide the optimal cancer treatment. [ABSTRACT FROM AUTHOR]

Micro-milling is widely used in aerospace and precision optical part manufacturing. Residual stress is an important index of surface integrity, which signally affects the performance of the micro-parts. This paper presents an analytical model to predict micro-milling residual stresses considering tool edge radius, material strengthening effects, and initial stress. A micro-milling cutting force prediction model is proposed, in which tool edge radius and material strengthening effects are taken into account. The imaginary heat source is utilized to estimate the temperature distribution in the workpiece. This model considers the prediction results of cutting force and temperature as thermomechanical loads experienced by the workpiece. Also, the effect of initial stress is taken into account during the estimation of residual stresses. After loading, unloading, and stresses release, the results of residual stresses in micro-milling are finally obtained. Both the micro-milling cutting force and residual stresses prediction results are validated by NAK80 steel on a three-axis ultra-precision machine. The predicted results capture the experiment results well in terms of distribution and value. Finally, the model is analyzed and discussed. The influences of tool edge radius, rake angle, feed per tooth, and spindle speed on residual stresses are preliminarily explored. [ABSTRACT FROM AUTHOR]

Previous research has shown that the presence of English word spellings facilitates children's oral vocabulary learning. Whether a similar orthographic facilitation effect may exist in Chinese is interesting but not intuitively obvious due to the character writing system representing morphosyllabic but not phoneme-size information, and the more direct semantic-orthography mapping but less consistent orthography and pronunciation correspondence in Chinese. The current study aims to examine whether semantic and phonological information provided by character radicals affects oral vocabulary learning of Chinese children. Twenty-four second graders studied made-up associations between 12 spoken labels and pictures accompanied either by accurate phonological information characters, misleading phonological information characters, or no orthography. Half of phonologically accurate or misleading characters were semantically accurate or misleading. Pictures prompted recall of spoken labels without orthography present on tests. Results showed that exposure to characters which accurately represent sounds and meanings during learning did not enhance recall of the spoken labels compared to no orthography in early trials. But exposure to characters, which misrepresent sounds and meanings, significantly impeded vocabulary learning compared to no orthography. [ABSTRACT FROM AUTHOR]

Background: Deregulation of microRNAs (miRNAs) has been associated with a variety of cancers, including non-small cell lung cancer (NSCLC). Here, we investigated anomalous miR-613 expression and its possible functional consequences in primary NSCLC samples and NSCLC-derived cell lines. Methods: The expression of miR-613 was measured by quantitative RT-PCR in 56 primary NSCLC tissues and adjacent non-tumor tissues. The effect of miR-613 up- or down-regulation in NSCLC-derived cells was evaluated in vitro by cell viability and colony formation assays and in vivo by growth assays in xenografted nude mice. Results: Using quantitative RT-PCR, we found that miR-613 was down-regulated in 76.8 % (43/56) of the primary NSCLC tissues tested when compared to the adjacent non-tumor tissues. We also found that the miR-613 mimic used reduced in vitro cell viability and colony formation by inducing cell cycle arrest in NSCLC-derived cells, and inhibited in vivo tumor cell growth in xenografted nude mice. Inversely, we found that the miR-613 inhibitor used increased the viability and colony forming capacity of NSCLC-derived cells and tumor cell growth in xenografted nude mice. In addition, we identified CDK4 as a potential target of miR-613 using in silico Miranda predictions. Subsequent dual-luciferase reporter assays revealed that CDK4 acts as a direct target of miR-613. Concordantly, we found that both miR-613 mimics and inhibitors could decrease and increase CDK4 protein levels in NSCLC-derived cells, respectively. Conclusions: From our results we conclude that miR-613 may act as a tumor suppressor in NSCLC and may serve as a tool for miRNA-based NSCLC therapy. [ABSTRACT FROM AUTHOR]

Background: Presurgery serum osteopontin (OPN) level has been demonstrated to correlate to tumor recurrence and survival of hepatocellular carcinoma (HCC) patients. This study investigated the postoperative dynamic changes of serum OPN level and its clinical significance in HCC patients. Methods: Presurgery serum OPN levels were measured by enzyme-linked immunosorbent assay in cohort A of 179 HCC patients and were compared with the multiple controls including different kinds of liver diseases and healthy individuals. In cohort B of 110 patients with resectable HCCs, besides preoperative assays, serum OPN was monitored at 1 week, 1, and ≥2 months after operation. Results: The baseline presurgery serum OPN of HCC patients was significantly higher than that of the patients with the other kinds of liver diseases ( p < 0.0001). The prognostic values of presurgery serum OPN level in HCC patients were further confirmed. The postsurgery OPN levels were significantly elevated within 1 week after HCC resection, then decreased at 1 month and reached the nadir later than 2 months after operations. It increased again at the time of tumor recurrence, then declined after the second removal of recurrent HCCs. Moreover, postoperative OPN in α-fetoprotein-negative and -positive HCC patients had the same changing pattern; it only correlated to liver function and C-reactive protein level. Conclusions: After a transient fluctuation, serum OPN levels significantly decrease after curative resection of HCCs. Postoperative serum OPN could serve as a surrogate serologic biomarker for monitoring treatment response and tumor recurrence after HCC resection, including α-fetoprotein-negative ones. [ABSTRACT FROM AUTHOR]

Circulating microRNAs (miRNAs) were found to exist in serum/plasma in a highly stable, cell-free form, and aberrantly expressed in many human diseases. Currently, the expression levels of circulating miRNAs are estimated by quantitative real-time polymerase chain reaction. However, no study has systematically evaluated reference genes for evaluating circulating microRNA expression. This study describes the identification and characterization of an appropriate reference gene for the normalization of circulating miRNA levels in hepatitis B virus (HBV)-infected patients and healthy people. Ten miRNAs that resemble the mean expression of the TaqMan low density array together with U6, RNU6B, and miR-16 were validated with two algorithms, geNorm, and NormFinder, after ensuring their equivalent expression between the two study groups. The combination of miR-26a, miR-221, and miR-22* is recommended as the most stable set of reference genes for circulating miRNA evaluation in HBV patients and healthy people. [ABSTRACT FROM AUTHOR]

Aim:To investigate the anti-cancer effects of p21WAF1/CIP1 transcriptional activation induced by dsRNAs in hepatocellular carcinoma (HCC) cell lines.Methods:HCC cell lines BEL7402, SMMC-7721, MHCC97L, MHCC97H, and MHCCLM3 were used. HCC cells were treated with dsP21-322 (50 nmol/L), dsControl (50 nmol/L), siP21 (50 nmol/L), or mock transfection. The expression of p21 was detected using quantitative PCR and Western blot. The effects of RNA activation on HCC cells were determined using cell viability assays, apoptosis analyses and clonogenic survival assays. Western blot was also conducted to detect the expression of Bcl-xL, survivin, cleaved caspase-3, cleaved caspase-9 and cleaved PARP.Results:At 72 to 120 h following the transfection, dsP21-322 markedly inhibited the viability of HCC cells and clone formation. At the same times, dsP21-322 caused a significant increase in HCC cell apoptosis, as demonstrated with cytometric analysis. The phenomena were correlated with decreased expression levels of the anti-apoptotic proteins Bcl-xL, surviving, and increased expression of cleaved caspase-3, cleaved caspase-9 and cleaved PARP.Conclusion:RNA-induced activation of p21 gene expression may have significant therapeutic potential for the treatment of hepatocellular carcinoma and other cancers. [ABSTRACT FROM AUTHOR]

Background: We investigated environmental and occupational exposures and smoking history (while controlling for demographics) in a population of Mexican-American lung cancer cases and controls from the Houston metropolitan area. Methods: Data were collected between 1991 and 2005 as part of an on-going multi-racial/ethnic, lung cancer case-control study. Cases included 212 Mexican-American lung cancer cases from UT MD Anderson Cancer Center. Controls ( n = 328) were recruited from Houston's largest multispecialty group practice and frequency matched to the cases by age (±5 years), sex, and ethnicity. Environmental and occupational factors were analyzed and odds ratios and 95% confidence intervals were calculated using logistic regression. Results: We detected elevated risks of lung cancer associated with pesticide exposure and found conventional and antimicrobial (e.g., sterilizers, disinfectants, antiseptics) pesticides were associated with an increased risk of lung cancer in Mexican-Americans (conventional pesticides and antimicrobial pesticides combined: OR = 1.80, 95% CI 1.13-2.86; conventional pesticides: OR = 2.05, 95% CI 1.23-2.39; antimicrobial pesticides: OR = 2.48, 95% CI 1.46-4.21). Conclusions: Although we found over a two-fold increased risk of lung cancer among Mexican-Americans for pesticides, we could not identify individual pesticides. Our findings are an important preliminary step in identifying factors that are specifically associated with lung cancer risk among Mexican Americans. [ABSTRACT FROM AUTHOR]