ABSTRACT
Objective To investigate the inhibitory effect of melatonin on the migration and invasion of gastric cancer cell and the underlying molecular mechanism. Methods Human gastric cancer SGC-7901 cells were treated with different concentrations of melatonin ( 0. 1, 1, 2 and 4 mmol/L ) for 24 hours, and the changes in the migration and invasion of gastric cancer cells were detected by scratch test and Transwell assay. The expressions of matrix metalloproteinase ( MMP) -2 and MMP-9 in the supernatant were detected by ELISA kit. The changes of MMP-2, MMP-9, intercellular cell adhesion molecule-1 ( ICAM-1 ) and CD44 expressions were detected by using Real-time PCR. The protein expressions of ICAM-1, CD44, p-P38, P38 and phosphorylated mitogen-activated protein kinase kinase ( p-MKK) 3/6 were detected by Western blotting. Results Melatonin inhibited the migration and invasion of gastric cancer cells in a dose- dependent manner. Compared with the blank control group, melatonin reduced the expression of MMP-2, MMP-9, ICAM-1 and CD44, and inhibited the expressions of p-P38, P38 and p-MKK3/6 in gastric cancer cells. Conclusion Melatonin inhibits the migration and invasion of gastric cancer cells by inhibiting the expressions of MMP-2, MMP-9, ICAM-1 and CD44. Inhibition may be related to the p38MAPK signaling pathway.
ABSTRACT
<p><b>OBJECTIVE</b>To identify and characterize the polypeptides specifically binding to human B type natriuretic peptide (BNP) screened from 12TM phage display peptide library.</p><p><b>METHODS</b>The BNP-binding peptides were screened from 12TM phage display peptide library and identified by ELISA.</p><p><b>RESULTS</b>After 4 rounds of screening, 10 of the 16 phage clones were identified as the positive clones which could bind to BNP. Five amino acid sequences were obtained in the 10 positive clones. Dose-dependent ELISA results demonstrated that the screened polypeptides could specifically bind to BNP.</p><p><b>CONCLUSION</b>These screened polypeptides can bind specifically to BNP, which provides a basis for further research on expression and purification of anti-BNP polypeptides and the development of the detection kit of BNP.</p>