Mechanism of colon cancer cell apoptosis induced by telocinobufagin: role of oxidative stress and apoptosis pathway / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of telocinobufagin on viability and apoptosis of colorectal cancer (CRC) cells and explore the mechanism of telocinobufagin-induced apoptosis.</p><p><b>METHODS</b>MTT assay was performed to detect the viability of CRC cells exposed to telocinobufagin. Nuclear staining with Hoechst 33342 and flow cytometry were used to analyze the cell death of CRC cells. Expressions of proteins related with cell apoptosis and oxidative stress were determined with Western blotting.</p><p><b>RESULTS</b>Telocinobufagin decreased the viability of CRC cells in a time- and dose-dependent manner. The presence of karyopycnosis and apoptotic bodies together with the results of flow cytometry suggested that telocinobufagin induced cell apoptosis to cause cell death. Western blotting showed that telocinobufagin exposure of the cells resulted in upregulated p53 and Bax protein expressions and promoted cleavage of caspase 9 and PARP. Telocinobufagin induced phosphorylation of Bad and PARP cleavage, and suppressed phosphorylation of IKBα and TAK1 and expression of survivin in the cells.</p><p><b>CONCLUSION</b>Telocinobufagin can decrease the viability of CRC cells by inducing cell apoptosis, which involves p53-mediated Bax activation and inhibition of the IAP pathway.</p>

Experimental study on vascular bundle implantation combined with cellular transplantation in treating rabbit femoral head necrosis / 中国骨伤

<p><b>OBJECTIVE</b>To discuss the feasibility of vascular bundle implantation combined with allogeneic bone marrow stromal cells (BMSCs) transplantation in treating rabbit femoral head osteonecrosis and bone defect, in order to explore a new method for the treatment of femoral head necrosis.</p><p><b>METHODS</b>Thirty-six New Zealand rabbits were randomly divided into three groups,with 12 rabbits in each group. Bilateral femoral heads of the rabbits were studied in the experiment. The models were made by liquid nitrogen frozen, and the femoral heads were drilled to cause bone defect. Group A was the control group,group B was stem cells transplantaion group of allograft marrow stromal,and group C was stem cells transplantation group of allograft marrow stromal combined with vascular bundle implantation. Three rabbits of each group were sacrificed respectively at 2, 4, 8, 12 weeks after operation. All specimens of the femoral heads were sliced for HE staining. Furthermore ,vascular density and the percentage of new bone trabecula of femoral head coronary section in defect area were measured and analyzed statistically.</p><p><b>RESULTS</b>In group C,new bone trabecula and original micrangium formed at the 2nd week after operation; new bone trabecula was lamellar and interlaced with abundant micrangium at the 8th week;at the 12th week,the broadened,coarsened bone trabecula lined up regularly,and the mature bone trabecula and new marrow were visible. At the 2nd week after operation,there was no statistical significance in the percentage of new bone trabecula of femoral head coronary section in defect area between group B and C. While at 4, 8, 12 week after operation, vascular density and the percentage of new bone trabecula of femoral head coronary section in defect area of group C was higher than that of group B.</p><p><b>CONCLUSION</b>Allogeneic bone marrow stromal cells cultured in vivo can form new bone trabecula, and can be applied to allotransplant. Vascular bundle implanted into the bone defect area of femoral head necrosis could improve blood supply, and promote the formation of bone trabecula.</p>

Clinical significance of blood and fecal tumor M2-pyruvate kinase expression in patients with colorectal cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the clinical significance of blood and fecal expression of tumor M2-pyruvate kinase (Tumor M2-PK) in patients with colorectal cancer.</p><p><b>METHODS</b>With 22 healthy subjects as controls, 44 patients with CRC were examined for tumor M2-PK in serum and fecal samples using a sandwich enzyme immunoassay.</p><p><b>RESULTS</b>The sensitivity of serum and fecal tumor M2-PK for detecting CRC was 59.1% and 63.6% with a specificity of 86.4% and 81.8%, respectively. The serum and fecal levels of tumor M2-PK showed a significant correlation in CRC patients.</p><p><b>CONCLUSION</b>Tumor M2-PK has good sensitivity and specificity in the diagnosis of CRC.</p>