Dual induction of caspase 3- and transglutaminase-dependent apoptosis by acyclic retinoid in hepatocellular carcinoma cells

<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma has a high mortality rate due to its rate of recurrence. Acyclic retinoid prevents recurrence of hepatocellular carcinoma in patients after surgical removal of their primary tumors by inducing apoptosis in hepatocellular carcinoma cells, although the molecular mechanisms of action are not understood.</p> <p>Methods</p> <p>Human hepatocellular carcinoma cells in culture, as well as nude mice transplanted with hepatocellular carcinoma cells and rats given with <it>N</it>-diethylnitrosamine were treated with acyclic retinoid. Changes in activated caspase 3 and transglutaminase 2 (TG2) levels, Sp1 cross-linking and its activities, expression of epidermal growth factor receptor, and apoptotic levels were measured.</p> <p>Results</p> <p>Acyclic retinoid simultaneously stimulated the activation of caspase 3, and the expression, nuclear localization and crosslinking activity of TG2, resulting in crosslinking and inactivation of the transcription factor, Sp1, thereby reducing expression of epidermal growth factor receptor and cell death in three hepatocellular carcinoma cell lines. These effects were partially restored by a caspase inhibitor, transfection of antisense TG2, restoration of functional Sp1, or an excess of epidermal growth factor. Nuclear expression of TG2 and crosslinked Sp1, as also activated caspase 3 were found in both hepatocellular carcinoma cells transplanted into nude mice and cancerous regions within the liver in <it>N</it>-diethylnitrosamine-induced hepatocarcinogenesis model in rats, following treatment of animals with acyclic retinoid.</p> <p>Conclusions</p> <p>Treatment with acyclic retinoid produces a dual activation of caspase 3 and TG2 induced apoptosis of hepatocellular carcinoma cells via modification and inactivation of Sp1, resulting in reduced expression of epidermal growth factor receptor.</p

精神疾患患者による朝顔栽培への参加継続要因の検討

精神科病院に入院中の精神疾患患者38名を対象に、フェイススケールを用いて園芸作業による気分の変化の調査、および参加観察を行った。園芸作業への参加継続群と非継続群を比較した結果、継続群は“園芸作業が気分の安定に効果的な群”、非継続群が“園芸作業が気分の安定に効果的でない群”であることが明らかとなった。継続群、非継続群の結果より、朝顔栽培への参加が継続できない要因は、精神症状が安定していないことが考えられた。また、参加継続要因は、精神症状が安定していること、朝顔の成長を予期できること、やりがいを見いだせること、他者との集団行動がとれること、前年度から継続して参加していることの5点であると考えられた

Irradiation History of Itokawa Regolith Material Deduced from Noble Gases in the Hayabusa Samples

Noble gas isotopes were measured in three rocky grains from asteroid Itokawa to elucidate a history of irradiation from cosmic rays and solar wind on its surface. Large amounts of solar helium (He), neon (Ne), and argon (Ar) trapped in various depths in the grains were observed, which can be explained by multiple implantations of solar wind particles into the grains, combined with preferential He loss caused by frictional wear of space-weathered rims on the grains. Short residence time of less than 8 million years was implied for the grains by an estimate on cosmic-ray-produced 21Ne. Our results suggest that Itokawa is continuously losing its surface materials into space at a rate of tens of centimeters per million years. The lifetime of Itokawa should be much shorter than the age of our solar system