ABSTRACT
Objective To investigate the effect and underlying mechanism of Caudatin combined with Gefitinib on Gefitinib resistance induced by HGF in PC-9.Methods Model of EGFR-TKIs resistance in PC-9 cells was induced by exogenous HGF and co-cultured with MRC-5.Caudatin was tested as a drug resistant modulator to reverse the resistance of Gefitinib in PC-9 cells induced by HGF by MTT assay.Western blot was performed to observe the mechanism of Caudatin combined with Gefitinib reversing the resistance of PC-9 induced by HGF.Results The resistance of gefitinib to PC-9 was induced by exogenous HGF and co-cultured with MRC-5 which could reduce relative inhibitory rate ( P<0.05 ) .Neither caudatin ( 0-32 μM ) or Gefitinib (1μM) alone could significantly inhibit proliferation of PC-9 in the presence of HGF, which could be inhibited in a dose-dependent manner by Caudatin combined with Gefitinib ( P<0.05 ); Caudatin combined with Gefitinib down-regulated the phosphorylation levels of Met and PI3K/Akt simultaneously (P<0.05).Conclusion Caudatin could reverse the drug resistance of Gefitinib in PC-9 induced by HGF, the mechanism of which may be related to the inhibition of Met/PI3K/AKT pathway.
ABSTRACT
<p><b>OBJECTIVE</b>To develop a GC method to determine the content of caryophyllene in Eupatorium fortune.</p><p><b>METHOD</b>The samples were determined on a DB-1701 (0.32 mm x 30 m, 0.25 microm) quartz capillary column. And the sample was extracted with ethanol by the ultrasonic assisted extraction.</p><p><b>RESULT</b>The calibration curve of caryophyllene is liner over the range of 0.002-2.0 g x L (-1) (R2 = 1). The recovery was from 96.76% to 104.15%.</p><p><b>CONCLUSION</b>The method is accurate, simple with a good reproducibility. It can be used to control the quality of E. fortune.</p>