LINE-1 retrotransposition events regulate gene expression after X-ray irradiation.

Long interspersed nuclear element-1 (LINE-1) retrotransposons are mobile elements that insert into new genomic locations via reverse transcription of an RNA intermediate. The mechanism of retrotransposition is not entirely understood. The integration of these elements occurs by target-primed reverse transcription (TPRT), which initiates double-strand breaks (DSBs) during the LINE-1 integration.

LINE-1 retrotransposition events affect endothelial proliferation and migration.

Long interspersed nuclear element-1 (LINE-1, L1) is a retrotransposon which affects the human genome by a variety of mechanisms. While LINE-1 expression is suppressed in the most somatic human cells, LINE-1 elements are activated in human cancer. Recently, high accumulation of LINE-1-encoded ORF1p and ORF2p in endothelial cells of mature human blood vessels was described.

Radiation-induced bystander effects in malignant trophoblast cells are independent from gap junctional communication.

It is controversially discussed that irradiation induces bystander effects via gap junction channels and/or diffusible cellular factors such as nitric oxide or cytokines excreted from the cells into the environment. But up to now the molecular mechanism leading to a bystander response is not well understood. To discriminate between both mechanisms of bystander response, (i) mediated by gap junctional communication and/or (ii) mediated by diffusible molecules, we used non-communicating Jeg3 malignant trophoblast cells transfected with inducible gap junction proteins, connexin43 and connexin26, respectively, based on the Tet-On system.

The PTB microbeam: a versatile instrument for radiobiological research.

The PTB microbeam is routinely used for the irradiation of living cells using protons (1-20 MeV) and alpha particles (1-28 MeV). The beam diameter is approximately 2 microm (fwhm), achieved by focussing, resulting in an excellent energy resolution and practically no scattered particles. Recently, an electrostatic beam scanner was added to the facility which allows targeting of each cell within 1 ms.

Cell line specific modulation of connexin43 expression after exposure to ionizing radiation.

Gap junctional intercellular communication plays a significant role in mediating radiation-induced bystander effects. However, the level of Cx43 itself is influenced by ionizing radiation, which could modify the bystander effect. Here we have investigated several cell lines for the modulation of Cx43 expression 24 h after irradiation with 5 Gy X-rays.

Single-nucleotide polymorphisms in the promoter region influence the expression of the human follicle-stimulating hormone receptor.

Objective: To characterize novel single-nucleotide polymorphisms (SNPs) in the human FSH receptor (FSHR) promoter region.

Design: Retrospective and basic research study.

Setting: University hospital.