MicroRNA-194 suppresses prostate cancer migration and invasion by downregulating human nuclear distribution protein.

Human NudC nuclear distribution protein (hNUDC) is differentially expressed between normal and cancer cells. Based on its marked altered expression and its roles in modulating cell division, cytokineses and migration, a detailed understanding of the mechanisms regulating hNUDC expression in cancer cells is critical. In this study, we identified miR-194 as a downstream target of hNUDC and linked its expression to reduced metastatic capacity and tumorigenicity of prostate cancer (PCa) cells. Using miRNA target prediction programs, hNUDC mRNA was found to contain a potential binding site for miR-194 within its 3'UTR. A Reporter assay confirmed that post-transcriptional regulation of hNUDC was dependent on the miR-194 binding site. Forced expression of miR-194 in PCa cell lines, PC-3 and DU-145, led to a decrease in the mRNA and protein levels of hNUDC. Overexpression of miR-194 in these cells inhibited cell migration and invasion, and induced multinucleated cells. Our data showed that hNUDC knockdown by siRNA significantly reduced the migration and invasion in the PC-3 and DU-145 cells, phenocopying the results of miR-194 overexpression. Furthermore, lentivirus-mediated stable expression of miR-194 in PCa cells reduced the ability of colony formation as detected by a soft agar assay and exhibited significantly less tumorigenic ability in vivo. Our results suggest a novel role for miR-194 in effectively controlling cell metastatic processes in PCa cells via the regulation of hNUDC expression.

[Topsoil phosphorus forms and availability of different soil and water conservation plantations in typical black soil region, northeast China].

Aiming to understand soil phosphorus status of plantations in typical black soil region of Northeast China, the topsoil (0-10 cm) phosphorus fractionations and its availability were examined in four soil and water conservation plantations dominantly composed of Larix gmelini, Fraxinus mandshurica, Pinus sylvestris var. mongolica and Populus nigra var. italica x P. cathayan, respectively. The results showed that total P, Olsen-P and the concentration of different P fractionations in F. mandshurica and P. nigra var. italica x P. cathayan plantations were significantly higher than that of the other two coniferous plantations. Organic P was the major fractionation in the four plantations' topsoil, and sodium hydroxide extractable organic P (NaOH-Po ) representing moderately labile organic phosphorus was predominant, which accounted for 58.9% of total P. The contents of H2O-Pi and NaHCO3-P which were more labile to plant were lower, only accounting for 1.2% and 6.6% of total P, respectively. Except for NaHCO3-Po, all the other P fractions of four plantations correlated with each other, and they also had significant correlations with soil organic matter, total P, Olsen-P. Compared with the coniferous plantations, the broadleaf plantations presented higher availability of phosphorus.

[Surrounding characteristics of preferential flow in cultivated typical black soils of northeast China].

Taking the cultivated soils in typical black soil region of Northeast China as test objects, and by using dye tracer and double-ring infiltrometer techniques and photograph interpretation method, this paper measured and analyzed the dye-stained width and dye-stained coverage of soil transverse and longitudinal sections as well as the field maximum dye-stained depth, aimed to approach the water flow movement pattern and distribution characteristics in test soils. At soil depth 0-15 cm, matrix flow was the main soil water flow movement pattern; at depth 15-20 cm, lateral flow was observed, and the average dye-stained width and dye-stained coverage reached their maximum, being 23 cm and 20.73%, respectively. At depth 20-67 cm, the main soil water flow movement pattern was macro-pore flow, with cracks and macro-pores as the main preferential routes. The cracks at depth 20-35 cm made the preferential flow have distinct surrounding characteristics, and the macro-pores at depth 40-67 cm were the main preferential routes. Due to the existence of the preferential routes of cracks and macro-pores, the migration velocity of water in soil increased by 4.5 times, which could not only cause water loss, but also accelerate the migration of pesticides to ground water. It was suggested that these preferential routes should be decreased or eliminated during the cultivation and management on cultivated typical black soils.

[Optimal disposition of water conservation forests in watershed].

Based on the measurements of canopy interception, litter water-holding capacity and soil water storage of different stands in the Erdaoqiao watershed of upper Nenjiang River, the optimal disposition of water conservation forests in this watershed was approached by the method of analytical hierarchy process (AHP). The results showed that in this watershed, the optimal vegetation structure should be 24. 86% of natural birch forest, 16. 30% of natural Dahurian birch forest, 44. 49% of natural broadleaved mixed forest, 10. 88% of larch plantation, and 3. 47% of grassland. After optimization, the water conservation capacity of the watershed could be improved obviously, with soil available and maximum moisture contents increased by 33. 05% and 27. 78% , re-