We report a phenomenon wherein induction of cell death by a variety of means in wing imaginal discs of Drosophila larvae resulted in the activation of an anti-apoptotic microRNA, bantam. Cells in the vicinity of dying cells also become harder to kill by ionizing radiation (IR)-induced apoptosis. Both ban activation and increased protection from IR required receptor tyrosine kinase Tie, which we...

The controversial use of a linear, no threshold extrapolation model for low dose risk assessment has become even more so in light of the recent reports on the bystander phenomenon. The answer to the question as to which of the two phenomena, bystander versus adaptive response, is more important has practical implication in terms of low dose radiation risk assessment. In this review, genotoxicit...

PURPOSE To observe the effect of guggulsterone (GS) on the radiation response in human cancer cell lines. MATERIALS AND METHODS The radiation response of cancer cells treated with GS was observed by cell survival studies, cell growth assay, NF-κB activity assay, western blotting of some key growth promoting receptors, the DNA repair protein γH2AX, and flow cytometry for DNA analyses. RESULT...

The existence of radiation-induced bystander effects mediated by diffusible factors is now accepted, but the mechanisms and precise behavior at low doses remain unclear. We exposed cells to gamma-ray doses in the range 0.04 mGy-5 Gy, harvested the culture medium, and transferred it to unirradiated reporter cells. Calcium fluxes and clonogenic survival were measured in the recipients. We show ev...

Senescence-induced therapy has been improved to increase its cytotoxicity and reduce the resistance of breast cancer cells chemotherapy agents. An example a potential senescence-inducing agent is black cumin oil (BCO) because one major compounds, α-pinene, can induce senescent cells. This study aims explore activity BCO in HER2-overexpressing (MCF7/HER2). The yield obtained from hydro-distillat...

The estrogen-induced 52K protein secreted by human breast cancer cells is a lysosomal protease recently identified as a pro-cathepsin D by sequencing several cDNA clones isolated from MCF7 cells (Augereau et al., Mol. Endocr.). Using one of these clones, we detected, in MCF7 cells, a 2.2 kb mRNA whose level was rapidly increased 4- to 10-fold by estradiol, but not by other classes of steroids. ...

We report data demonstrating that zebrafish embryos irradiated by α-particles can release a stress signal into the water, which can be communicated to the unirradiated zebrafish embryos sharing the same water medium, and then these unirradiated zebrafish embryos can release a feedback stress signal back to the irradiated embryos. The effects of radiation on the whole embryos were studied throug...

Genotoxic treatments elicit DNA damage response (DDR) not only in cells that are directly exposed but also in cells that are not in the field of treatment (bystander cells), a phenomenon that is commonly referred to as the bystander effect (BE). However, mechanisms underlying the BE remain elusive. We report here that etoposide and ultraviolet (UV) exposure stimulate the production of microvesi...

Communication between cells is important for maintaining homeostasis, the physiological regulatory processes that keep the internal environment of a system in a constant state. A disease can disturb the internal equilibrium of cells, and this can be further disrupted by various therapies. Malignances are the diseases that need to be treated by highly aggressive methods, such as radiotherapy, wh...