ABSTRACT
AIM:To investigate the stemness of mouse triple-negative breast cancer (TNBC) 4T1 cells induced by doxorubicin (DOX) and the underlying mechanism.METHODS:The 4T1 cells and MDA-MB-468 cells were treated with DOX at different concentrations (0, 0.05, 0.1 and 0.5μmol/L) for 24 h, and the shape and viability of the cells were observed.The concentration of DOX at 0.1μmol/L was chosen as the optimal concentration for the following experiments.The 4T1 cells and MDA-MB-468 cells resistant to DOX were established by continuous stimulation with DOX for 4 weeks, and named as 4T1-DOX and MDA-MB-468-DOX.Sphere formation assay was used to detect the stemness of 4T1cells and MDA-MB-468 cells.The expression of CD133 was observed by immunofluorescence staining.The expression of CD44 was analyzed by flow cytometry.The protein levels of Stat3, phosphorylated Stat3 (p-Stat3) and Oct-4 were determined by Western blot.RESULTS:The sphere formation ability of the 4T1-DOX cells was stronger than that of the 4T1control cells.The 4T1-DOX cells expressed high levels of the stemness markers CD133 and CD44 as compared with the 4 T1 cells (P<0.05).Furthermore, the 4T1-DOX cells exhibited enhanced activation of Stat3 (p-Stat3) and increased expression of Oct-4 (P<0.05) , while the expression of total Stat3 had no obvious variation.In addition, when activation of Stat3 was inhibited by WP1066, the protein levels of p-Stat3, Oct-4 and CD44 were down-regulated (P<0.05).Furthermore, inhibition of Stat3 phosphorylation reduced the sphere formation ability of the 4T1-DOX cells (P<0.05).CONCLUSION:DOX induces the stemness of mouse TNBC 4T1 cells through Stat3-Oct-4 signaling pathway.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the values of surface electromyography (sEMG) in the treatment of adolescent idiophathic scoliosis (AIS) with non-surgical therapy.</p><p><b>METHODS</b>From October 2011 to May 2012, the data of 33 patients with AIS underwent traditional spinal balanced therapy were analyzed. There were 14 males and 19 females with an average age of (15.40 +/- 3.01) years,ranging in Cobb angle from 13 degrees to 40 degrees, course of disease more than 3 months. X-rays showed 21 cases were type C and 9 cases were type S. Preoperative and postoperative 6 months, Cobb angle, the ratio of averaged electromyography paramete (AEMG), security of treatment were observed.</p><p><b>RESULTS</b>Thirty cases (90.9%) accomplished the treatment and detection. No harmful effects to vital sign was found and no fracture, dislocation, apopsychia, infection of pin hole was found. There was positive correlation between the ratio of AEMG and Cobb angle (P = 0.003). The ratio of AEMG decreased after treatment,and indicated the improvement of myosthenic otherness.</p><p><b>CONCLUSION</b>sEMG can be used as a objective examination in evaluating difference of muscle electricity activity on both concaved and convex sides for patients of AIS, so it is a qualified objective examination for effectiveness evaluation and assessment aggravation risk, and has great value in clinic.</p>