Effect Of Andrographolide On Proliferation, Apoptosis And Na~+-K~+-ATPase Activity In Nasopharyngeal Cells

ObjectiveTo observe the effect of Andrographolide on the proliferation and apoptosis ofnasopharyngeal carcinoma in vitro, and explore its potential mechanism of resistance totumor.Methodsnasopharyngeal carcinoma line CNE-2was cultured in vitro, and was divided into4groups according to protocol:（1)control (0.1%DMSO);(2) AD low-dose group(1μmol/L AD);(3) AD medium dose group (5μmol/L AD);(4) AD high dose group(5μmol/L AD). After treatment, proliferation of CNE cells was detected by WST-8assay; Cell cycle and apoptosis were determined by flow cytometry; caspase-3andBcl-2expression was measured by Western blot; enzymic activity of Na+-K+-ATP wasdetermined by norganic phosphorus assay.Results(1) WST-8results showed that AD surpressed the CNE-2growth in time-anddose-dependence manners. The inhibited rate of CNE-2was increased with theconcentration of AD magnified at the same time point. And the inhibited rate of CNE-2was also raised with the time prolonged at the same concentration of AD.(2) The proportion of G0/G1of CNE-2cells was increased with the concentration ofAD increased(P<0.05); conversely,the proportion of S and G2/M was slightlyreduced.(3) Flow cytometry results showed that AD induced cells apoptosis in dose-effectmanners. When the concentration of AD was5μmol/L, the apoptosis rate was41.6% contrast to normal goup (P<0.05).(4) Activity of caspase-3subunit(17-kDa) was not dectected in normal group, CNE-2cells were treated by variety concentration of AD for24h,17-kDa activity subnunitwere increased significantly; conversely, Bcl–2level was decreased with the increasedconcentration of AD.(5) The enzymic activity of Na+-K+-ATP of CNE-2was inhibited with theconcentration of AD increased. When it was1.0μmol/L, the enzymic activity wasdroped to83%, when concentration was5.0μmol/L, it was droped to42%.Conclusions(1) AD could inhibit the proliferation of nasopharyngeal carcinoma cells, andinduces its apoptosis;(2) AD inhibit CNE-2cells apoptosis via inhibition of Bcl-2expression, decrease theenzymic activity of Na+-K+-ATP, and thus activate caspase-3.