RESUMO
ObjectiveTo investigate the role of protein kinase B （Akt） overexpression in the inhibition of human bladder cancer 5637 cell proliferation by erianin and related mechanisms. MethodThe 5637 cells stably over-expressing Akt were induced using the lentivirus vector. The 5637 cells infected with the empty vector were classified into blank group. Then the Akt group， empty vector combined with erianin （62.5 μg·L-1） group， and Akt combined with erianin （62.5 μg·L-1） group were set up. The cell viability was detected by cell counting kit-8 （CCK-8） assay， and the clone formation of 5637 cells in each group was determined in the clone formation experiment. The cell cycle distribution was detected by flow cytometry. Western blot was used to assay the protein expression levels of phosphorylated （p）-Akt， Akt， p21. The glycolysis of 5637 cells was determined in glucose uptake and lactate secretion assays. ResultCompared with the blank group， erianin inhibited the proliferation of bladder cancer 5637 cells （P<0.05）. Overexpression of Akt partially reversed the inhibitory effect of erianin on the proliferation of bladder cancer 5637 cells （P<0.05）. Clone formation assay showed that erianin inhibited the clone formation of bladder cancer 5637 cells （P<0.05）， which was partially reversed by the overexpressed Akt （P<0.05）. As revealed by comparison with the blank group， erianin arrested the bladder cancer 5637 cells in G1 phase （P<0.05）， which was also reversed by the overexpressed Akt （P<0.05）. Western bolt showed that erianin promoted the expression of p21 but suppressed the expression of p-Akt and Akt （P<0.05）. By contrast， the overexpression of Akt down-regulated the elevated p21 protein expression induced by erianin （P<0.05）. Compared with the blank group， erianin inhibited the glucose uptake and lactate secretion of bladder cancer 5637 cells （P<0.05）. Overexpression of Akt weakened the inhibitory effect of erianin against the glycolysis of 5637 cells （P<0.05）. ConclusionErianin is able to inhibit the proliferation of bladder cancer 5637 cells， promote the expression of p21， and inhibit the expression of p-Akt. Overexpressed Akt reduces the inhibitory effect of erianin on the proliferation of bladder cancer 5637 cells， suggesting that Akt plays an important role in the inhibition of 5637 cell proliferation by erianin， which has provided a new target for the application of erianin in the treatment of bladder cancer.