Thymoma is the most common
neoplasm of the anterosuperior mediastinum. Activation of the Wnt signaling pathway has a role in a variety of human
cancers. The present objective was to examine
c-Jun N-terminal kinase (JNK)
mRNA and
protein expression in
thymoma cells undergoing apoptosis subsequent to downregulation of Wnt4. Wnt4 and JNK
mRNA and
protein expression was analyzed by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry, respectively, in 15
thymoma tissues and 6 thymus
cyst tissues.
Thymoma cells were cultured and transfected with
shRNA plasmids targeting the Wnt4 gene. Wnt4 and JNK
protein expression was detected by western blot analysis. Apoptosis was analyzed using Wright-Giemsa staining,
Hoechst-33342/
propidium iodine double staining and flow cytometry. The results showed that Wnt4 and JNK
mRNA and
protein expression were significantly increased in
thymoma compared with normal thymus tissue. Subsequent to transfection,
thymoma Wnt4 and JNK
mRNA and
protein expression were significantly decreased in
shRNA-treated groups, with the strongest inhibition being 52.37%. Characteristic apoptotic morphological changes were observed and apoptosis increased. Overall, the present concluded that Wnt4 has an important role in
thymoma development, which appears to be activated through a JNK mediated planar cell polarity-like pathway.