Intestinal mucosal restitution occurs as a consequence of epithelial cell migration and reseals superficial wounds after injury. This rapid reepithelialization is mediated in part by a phospholipase C-gamma1 (PLC-gamma1)-induced Ca(2+) signaling, but the exact mechanism underlying such signaling and its regulation remains elusive. The small GTP-binding protein Rac1 functions as a pivotal regulator of several signaling networks and plays an important role in regulating cell motility. The current study tests the hypothesis that Rac1 modulates intestinal epithelial cell migration after wounding by altering PLC-gamma1-induced Ca(2+) signaling. Inhibition of Rac1 activity by treatment with its inhibitor NSC-23766 or Rac1 silencing with small interfering RNA decreased store depletion-induced Ca(2+) influx and suppressed cell migration during restitution, whereas ectopic overexpression of Rac1 increased Ca(2+) influx and promoted cell migration. Rac1 physically interacted with PLC-gamma1 and formed Rac1/PLC-gamma1 complex in intestinal epithelial cells. PLC-gamma1 silencing in cells overexpressing Rac1 prevented stimulation of store depletion-induced Ca(2+) influx and cell migration after wounding. Polyamine depletion inhibited expression of both Rac1 and PLC-gamma1, decreased Rac1/PLC-gamma1 complex levels, reduced Ca(2+) influx, and repressed cell migration. Overexpression of Rac1 alone failed to rescue Ca(2+) influx after store depletion and cell migration in polyamine-deficient cells, because it did not alter PLC-gamma1 levels. These results indicate that Rac1 promotes intestinal epithelial cell migration after wounding by increasing Ca(2+) influx as a result of its interaction with PLC-gamma1.
One of the most difficult decisions a woman can be faced with when choosing breast cancer treatment is whether or not to undergo breast conserving surgery or mastectomy. The factors that influence these treatment decisions are complex and involve issues regarding access to health care, concerns for cancer recurrence, and the impact of surgery on body image and sexuality. Understanding these factors will help practitioners to improve patient education and to better guide patients through this decision-making process. Although significant scientific and societal advances have been made in improving women’s choices for the breast cancer treatment, there are still deficits in the decision-making processes surrounding the surgical treatment of breast cancer. Further research is needed to define optimal patient education and shared decision-making practices in this area.
In well-compensated cirrhotic patients with early stage hepatocellular carcinoma, transplantation was associated with longer disease-free and overall survival. Patients undergoing resection did, however, have tumors with more advanced pathologic features. Patients best suited for initial resection as the treatment of hepatocellular carcinoma were those with a MELD score = 8 without evidence of hepatitis.
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