S100C/A11 is a key mediator of Ca2+-induced growth inhibition of human epidermal keratinocytes

An increase in extracellular Ca2+ induces growth arrest and differentiation of human keratinocytes in culture. We examined possible involvement of S100C/A11 in this growth regulation. On exposure of the cells to high Ca2+, S100C/A11 was specifically phosphorylated at 10Thr and 94Ser. Phosphorylation facilitated the binding of S100C/A11 to nucleolin, resulting in nuclear translocation of S100C/A11. In nuclei, S100C/A11 liberated Sp1/3 from nucleolin. The resulting free Sp1/3 transcriptionally activated p21CIP1/WAF1, a representative negative regulator of cell growth. Introduction of anti-S100C/A11 antibody into the cells largely abolished the growth inhibition induced by Ca2+ and the induction of p21CIP1/WAF1. In the human epidermis, S100C/A11 was detected in nuclei of differentiating cells in the suprabasal layers, but not in nuclei of proliferating cells in the basal layer. These results indicate that S100C/A11 is a key mediator of the Ca2+-induced growth inhibition of human keratinocytes in culture, and that it may be possibly involved in the growth regulation in vivo as well

Localization of S100C immunoreactivity in various human tissues.

Using 2-dimensional gel electrophoresis, we previously demonstrated that the S100C protein remarkably decreased after immortalization of normal human fibroblasts, and that this protein caused growth inhibition of human tumor cells when forcibly expressed in these cells, suggesting that S100C plays a significant role in tumor suppression. The present study was carried out to determine what type of human tissues express S100C protein, and, subsequently, whether the S100C content in these tissues changes after normal cells have been transformed into cancer cells. We found that ductal cells in various tissues were positively stained with the S100C protein. In comparison, epithelial cells in digestive organs such as the stomach, small intestine, and colon were not stained as strongly. When 14 pairs of human normal and cancerous tissues were stained with the antibody, decreases in the staining levels of S100C were observed in 6 kinds of cancerous tissues--from the bronchus, mammary duct, renal tubule, prostate, uterus, and testis--in comparison with staining in their normal counterparts. These results suggest that S100C is a new tumor marker protein, the expression of which significantly decreases after malignant transformation of human tissues.</p

Transmesocolic Hernia of the Ascending Colon with Intestinal Obstruction

An internal hernia may be either congenital or acquired. The reported incidence of such hernias is 1–2%. In rare cases, internal hernias are the cause of small bowel obstruction, with a reported incidence of 0.2–0.9%. Transmesocolic hernia of the ascending colon is especially rare. We report a case of transmesocolic hernia of the ascending colon with intestinal obstruction diagnosed preoperatively. A 91-year-old Japanese female was admitted to our hospital with abdominal distention and vomiting of 3 days duration. She had no past history of any abdominal surgery. Abdominal examination revealed distention and tenderness in the right iliac fossa. Abdominal computed tomography revealed ileus in the sac at the left side of the ascending colon and dilatation of the oral side of the intestine. We diagnosed a transmesocolic hernia of the ascending colon with intestinal obstruction and performed emergency surgery. At the time of operation, there was internal herniation of ileal loops through a defect in the ascending mesocolon, without any strangulation of the small bowel. The contents were reduced and the tear in the ascending mesocolon was closed. The postoperative course was uneventful and the patient was discharged 14 days after surgery. In conclusion, preoperative diagnosis of bowel obstruction caused by a congenital mesocolic hernia remains difficult despite the techniques currently available, so it is important to consider the possibility of a transmesocolic hernia when diagnosing a patient with ileus with no past history of abdominal surgery

シソウ トシテノ ホウリツ ヒトツバシ ガクエン 30ネン ノ カイコ

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