Up-regulation of 12(S)-lipoxygenase induces a migratory phenotype in colorectal cancer cells.

12(S)-Lipoxygenase (LOX) and its product 12(S)-hydroxyeicosatetraenic (HETE) acid have been implicated in angiogenesis and tumour invasion in several tumour types while their role in colorectal cancer progression has not yet been studied. We have analysed 12(S)-LOX expression in colorectal tumours and found gene expression up-regulated in colorectal cancer specimens for which the pathology report described involvement of inflammation. Using cell line models exposed to 12(S)-HETE or over-expressing 12(S)-LOX malignant cell growth as well as tumour cell migration was found to be stimulated. Specifically, Caco2 and SW480 cells over-expressing 12(S)-LOX formed fewer colonies from sparse cultures, but migrated better in filter-migration assays. SW480 LOX cells also had higher anchorage-independent growth capacity and a higher tendency to metastasise in vivo. Knock-down or inhibition of 12(S)-LOX inhibited cell migration and anchorage-independent growth in both 12(S)-LOX transfectants and SW620 cells that express high endogenous levels of 12(S)-LOX. On the cell surface E-cadherin and integrin-ß1 expression were down-regulated in a 12(S)-LOX-dependent manner disturbing cell-cell interactions. The results demonstrate that 12(S)-LOX expression in inflammatory areas of colorectal tumours has the capacity to induce an invasive phenotype in colorectal cancer cells and could be targeted for therapy.

[Investigation of the exposure to radiation of the embryo in the course of x-ray examination during pregnancy. 2nd communication: Estimation of the exposure to radiation using the area-dose or the tube-current-time product (author's transl)]. / Untersuchungen zur Strahlenexposition der Leibesfrucht bei Röntgenuntersuchungen während der Schwangerschaft. 2. Mitteilung: Abschätzung der Strahlenexposition aus dem Flächendosis- oder Röhrenstrom-Zeit-Produkt.

Thermoluminescence dosimetry of surface doses and doses near the uterus was performed during standardized X-ray examinations of the pelvis. Surface doses and the dose to the uterus were estimated from the available radiographic data referred to the tube and with the use of tissue/air ratios, and a comparison with the results of measurement was made. This comparison shows that the mean whole-body dose to the embryo can be estimated with a relative total risk of 20%, if all essential data of the exposure to radiation are present and if the position in depth of the embryo is known. Guiding data of the surface dose and of the dose to the uterus are given individually for fluoroscopic tests, a.-p. and lateral radiographs under standardized conditions of X-ray examination.

[Investigation of the exposure to radiation of the embryo/fetus in the course of radiographic examinations during pregnancy 1st communication: Tissue-air ratios for X-rays with tube voltages between 60 kV and 120 kV (author's transl)]. / Untersuchungen zur Strahlenexposition der Leibesfrucht bei Röntgenuntersuchungen während der Schwangerschaft. 1. Mitteilung: Gewebe-Luft-Verhältnisse für Röntgenstrahlen mit Röhrenspannungen zwischen 60 kV und 120 kV.

A relatively important radiation dose delivered to the embryo (fetus) is a decisive criterion, if interruption of pregnancy is considered for radiation-hygienic reasons. Several methods of assessment by calculation of the fetal exposition are discussed; in the last analysis, there are always needed the values of the relative depth doses or tissue-air ratios. The tissue-air ratios for the diagnostical X-ray qualities from 60 to 120 kV (total filtration 2.6 mm Al) were ascertained with the help of a water phantom. They are represented for layers from 0 to 20 cm by means of tables, and a comparison is made with data from the literature.