Epithelial Membrane Protein-2 Promotes Endometrial Tumor Formation through Activation of FAK and Src

Endometrial cancer is the most common gynecologic malignancy diagnosed among women in developed countries. One recent biomarker strongly associated with disease progression and survival is epithelial membrane protein-2 (EMP2), a tetraspan protein known to associate with and modify surface expression of certain integrin isoforms. In this study, we show using a xenograft model system that EMP2 expression is necessary for efficient endometrial tumor formation, and we have started to characterize the mechanism by which EMP2 contributes to this malignant phenotype. In endometrial cancer cells, the focal adhesion kinase (FAK)/Src pathway appears to regulate migration as measured through wound healing assays. Manipulation of EMP2 levels in endometrial cancer cells regulates the phosphorylation of FAK and Src, and promotes their distribution into lipid raft domains. Notably, cells with low levels of EMP2 fail to migrate and poorly form tumors in vivo. These findings reveal the pivotal role of EMP2 in endometrial cancer carcinogenesis, and suggest that the association of elevated EMP2 levels with endometrial cancer prognosis may be causally linked to its effect on integrin-mediated signaling

A comparative study of heavy metal accumulation and antioxidant responses in Vaccinium myrtillus L. leaves in polluted and non-polluted areas

The purpose of this study was to explore a possible relationship between the availability of metals in soil (Cd, Fe, Mn, Pb and Zn) and their concentrations in leaves of Vaccinium myrtillus L. as a species which has been reported to be a successful colonist of acid-and-heavy metal-contaminated soil. Analysis also concerned the antioxidant response of plants from three heavily polluted (immediate vicinity of: zinc smelter, iron smelter and power plant) and three relatively clean sites (nature reserve, ecological site and unprotected natural forest community) in southern Poland. The contents of glutathione, non-protein thiols, protein, proline and activity of guaiacol peroxidase in leaves of bilberry were measured. Generally, the concentrations of metals in the HNO(3) and CaCl(2) extracants of the soil from the polluted sites were higher. Moreover, the antioxidant responses were also elevated in bilberries in the polluted sites. Significant positive relationships between Cd, Pb and Zn concentrations in soil and in the plants were found. In the leaves of V. myrtillus from the polluted sites, higher concentrations of Cd, Pb and Zn were noted (In Miasteczko Śląskie respectively 6.26, 157.09 and 207.17 mg kg(−1) d.w.). We found a positive correlation between the increase in the NPTs and protein contents as well as the Cd, Pb and Zn concentrations in V. myrtillus. Cd, Pb and Zn also decreased guaiacol peroxidase activity. However, the activity of this enzyme increased under Fe. A decreasing trend in glutathione contents was observed with increasing iron and manganese concentrations in bilberry leaves. Parameters such as protein, non-protein –SH groups and changes in GPX activity seem to be universal, sensitive and correlated well with heavy metal stress

Growth and development dynamics in agronomic crops under environmental stress

Plants are exposed to different kinds of adverse environmental conditions during their life cycle that ablate their productivity. These environmental fluctuations have detrimental effects on the crops in terms of growth and development. Plants are highly susceptible to abiotic stresses including drought, salinity, high temperature, and increasing heavy metal concentration. The changing events related to climatic conditions are the signs of consternation for crops to maintain their productivity. Due to global warming, drought and high temperature are serious concerns regarding effective crop production. Salinity also adversely affects growth and productivity by disrupting normal physiology and biochemistry of plants. It causes osmotic disturbance, nutritional imbalance, malfunction of photosynthetic machinery, and oxidative stress. Rapid urbanization and industrialization are polluting the arable lands with heavy metals which not only affects crop productivity but also interferes with human health. In the modern era, heavy metals, like lead, cadmium, chromium, mercury, and copper are main environmental hazards, especially in regions of higher anthropogenic activity. Contamination of agricultural soils with heavy metals is a serious concern owing to its deleterious effects on agricultural productivity, phytotoxicity, food safety, and quality of the environment with ultimate impact on human health. All these abiotic stresses negatively affect several growth and developmental processes of plants which reduce the productivity of agronomic crop and also deteriorate the quality of produce. To cope with the situation, it is inevitable to understand the adverse effects of these abiotic factors on crop plants. This chapter provides comprehensive information on the impacts of abiotic stresses on crop plants