Inhibition of ERK signaling for treatment of ERRα positive TNBC.

Breast cancer is the second leading cause of cancer-related deaths in women and triple-negative breast cancer (TNBC), in particular, is an aggressive and highly metastatic type of breast cancer that does not respond to established targeted therapies and is associated with poor prognosis and worse survival. Previous studies identified a subgroup of triple-negative breast cancer patients with high expression of estrogen related receptor alpha (ERRα) that has better prognosis when treated with tamoxifen. We therefore set out to identify common targets of tamoxifen and ERRα in the context of TNBC using phosphoproteomic analysis.

Ellagic Acid, a Dietary Polyphenol, Selectively Cytotoxic to HSC-2 Oral Carcinoma Cells.

Background: The antiproliferative and apoptotic effects of ellagic acid, a dietary polyphenol, were studied.

Materials And Methods: The neutral red cytotoxicity assay compared the sensitivities of gingival fibroblasts and HSC-2 oral carcinoma cells to ellagic acid. The ferrous ion oxidation xylenol orange assay and levels of intracellular reduced glutathione were used to assess pro-oxidant nature of ellagic acid.

Research strategies in the study of the pro-oxidant nature of polyphenol nutraceuticals.

Polyphenols of phytochemicals are thought to exhibit chemopreventive effects against cancer. These plant-derived antioxidant polyphenols have a dual nature, also acting as pro-oxidants, generating reactive oxygen species (ROS), and causing oxidative stress. When studying the overall cytotoxicity of polyphenols, research strategies need to distinguish the cytotoxic component derived from the polyphenol per se from that derived from the generated ROS.

Pomegranate extract, a prooxidant with antiproliferative and proapoptotic activities preferentially towards carcinoma cells.

The antiproliferative and proapoptotic effects of pomegranate extract (PE), as correlated with its prooxidant activity, were studied. PE exerted greater antiproliferative effects towards cancer, than to normal, cells, isolated from the human oral cavity. In cell-free systems, PE generated hydrogen peroxide (H(2)O(2)) in cell culture media and in phosphate buffered saline, with prooxidant activity increasing from acidic to alkaline pH, and oxidized glutathione (GSH) in an alkaline, phosphate buffer.

Gingko biloba leaf extract induces oxidative stress in carcinoma HSC-2 cells.

The antiproliferative effects of a Gingko biloba leaf extract to cells from tissues of the human oral cavity were studied. Toxicity to carcinoma HSC-2 cells was correlated with the prooxidative nature of the extract. G.

RNase E autoregulates its synthesis in Escherichia coli by binding directly to a stem-loop in the rne 5' untranslated region.

RNase E autoregulates its production in Escherichia coli by governing the decay rate of rne (RNase E) mRNA. It does so by a mechanism that is dependent in part on hp2, a cis-acting stem-loop within the rne 5' untranslated region. In principle, hp2 could function either as a cleavage site for RNase E or as a binding site for that protein or an ancillary factor.

Theaflavin-3-gallate and theaflavin-3'-gallate, polyphenols in black tea with prooxidant properties.

This study compared the in vitro responses of human gingival fibroblasts and of carcinoma cells derived from the tongue to theaflavin-3-gallate (TF-2A) and theaflavin-3'-gallate (TF-2B), polyphenols in black tea. The antiproliferative and cytotoxic effects of the theaflavin monomers were more pronounced to the carcinoma, than to the normal, cells. In phosphate buffer at pH 7.

Theaflavin-3,3'-digallate, a component of black tea: an inducer of oxidative stress and apoptosis.

Treatment of human oral squamous carcinoma HSC-2 cells and normal GN46 fibroblasts with theaflavin-3,3'-digallate (TF-3), a polyphenol in black tea, showed a concentration and time dependent inhibition of growth, with the tumor cells more sensitive than the fibroblasts. In buffer and in cell culture medium, TF-3 generated reactive oxygen species, with lower levels detected in buffer amended with catalase and superoxide dismutase, indicating the generation of hydrogen peroxide and superoxide, respectively, and suggesting that TF-3 may be an inducer of oxidative stress. The toxicity of TF-3 was decreased in the presence of catalase, pyruvate, and divalent cobalt, all scavengers of reactive oxygen species, but was potentiated in the presence of diethyldithiocarbamate, an inhibitor of superoxide dismutase.