Effect of WW domail-containing oxidoreductase gene on apoptosis of papillary thyroid carcinoma cells and its mechanism

Objective To investigate the effects of WW domail-containing oxidoreductase (WWOX)-mediated apoptosis on papillary thyroid carcinoma in vitro and its possible mechanism. Methods A eukaryotic expression vector containing WWOX was transfected into papillary thyroid cancer cell line K1(recombinant plasmid group),and positive cell clones were selected and amplified. Synthesized small interfering RNA(siRNA) targeting WWOX(WWOX siRNA group) was transfected into TPC-1 cells.On the other hand, TPC-1 cells transfected with Lipofectamine 2000(liposomes control group)and vacant TPC-1 cells(blank control group) were used as controls.The expression of WWOX m RNA was detected by real-time quantitative reverse transcriptase-polymerase chain reaction(RT-qPCR).The effects of WWOX on apoptosis releated protein were analyzed by Western blotting. Results Recombinant plasmid group cells could steadily express WWOX mRNA, which was more than 4. 5 times higher than plasmid group and blank control group(P< 0. 05).The absorbance of TPC-1 cells decreased greatly after transfection with WWOX siRNA, which was 0. 2 times lower than in control groups(P< 0. 05).Forced expression of WWOX in K1 cells enhanced the expression of apoptosis releated protein. Conversely, knockdown of WWOX in TPC-1 cells using siRNA targeting WWOX decreased the expression of apoptosis releated protein. Conclusion WWOX can promote apoptosis of human PTC cells through a mechanism which may be assocoated with activation of the mitochondrial apoptosis pathway. Key words: WW domail-containing; Oxidoreductase gene; Apoptosis; Gene transfection