Expression of Plasminogen Activator Inhibitor-2 is Negatively Associated with Invasive Potential in Hepatocellular Carcinoma Cells

Objective To investigate the association between plasminogen activator inhibitor(PAI)-2 expression and invasive potential in hepatocellular carcinoma(HCC) cells.Methods The HCC cell lines with high,low,and non-metastatic potentials,namely MHCC97-H,MHCC97-L,and SMMC-7721 respectively,were cultured in vitro.Matrigel invasion assay and Western blot of PAI-2 protein expression were conducted.Results The number of invaded cells in MHCC97-L was significantly higher than that in SMMC-7721(P=0.005),whereas that in MHCC97-H was higher than in MHCC97-L(P=0.017) and SMMC-7721(P=0.001).Contrarily,PAI-2 protein expression was gradually reducing from SMMC-7721,MHCC97-L,to MHCC97-H(MHCC97-H vs.MHCC97-L,P<0.001;MHCC97-H vs.SMMC-7721,P=0.001;MHCC97-L vs.SMMC-7721,P=0.001).The Pearson's correlation analysis revealed a significant negative association between invaded cell number and PAI-2 expression(r= 0.892,P=0.001).Conclusion PAI-2 expression may be negatively associated with the invasive potential of HCC.

Natural Regeneration and Biological Invasion by Pinus caribaea Morelet in Two Vereda Sites: Woody Vegetation Response

Veredas are regarded as humid complexes of ecological, water and scenery significance in Cerrado biome related to water table outcrop. Direct alterations in these environments can lead to species diversity reduction and also facilitate biological invasion processes. Thus our study aims to investigate the natural regeneration, the coverage of woody vegetation and the invasive species in two sites in secondary successional stage in the central part of Cerrado biome. Our study was carried out at two sites located at Minas Gerais state, Brazil. We established plots randomly throughout transects laid perpendicularly to the vereda’s drain line. We used the line intercept method to analyze the vegetation coverage. We set five 10-m width transects in each of both areas, perpendicular to the vereda’s drain line to evaluate the distribution of invasive alien species in the two areas. The richness did not vary between communities (U = 67.50;p = 0.061);on the other hand we found significant difference in density estimates (U = 36.50;p = 0.002). We found significant difference between categories for soil coverage in both sites. Grasses showed the highest coverage when compared to the other categories (K = 45.06;p < 0.001 for site 1 and K = 67.47;p < 0.001 for site 2). We observed a zonation tendency in site 1, with a higher native grass coverage at middle and backwards zones (K = 7.734, p < 0.05). We only found Pinus caribaea Morelet individuals in the invasive species survey. We recorded 46 Pinus caribaea individuals at site 1 and 116 Pinus caribaea individuals at site 2. From the latter group we found 13 individuals within the vereda and 103 in the surrounding vegetation. Both sites have a high natural woody plant regeneration potential although the presence of alien grasses in the veredas’ edge and Pinus caribaea all over the humidity gradient highlights the vulnerability of these areas to biological invasion.