The Role Of AMPK/ACC Signaling Pathway In TRPP2-Mediated Proliferation And Apoptosis Of Head And Neck Tumor

Objective:To investigate whether knockdown of TRPP2 affects AMP-activated protein kinase–acetyl-Co A carboxylase(AMPK-ACC)signaling pathway and Fa Du cell proliferation,and the association between AMPK / ACC,AMPK / pancreatic ER kinase(PERK)/ eukaryotic initiation factor 2α(e IF2α)and transient receptor potential polycystic 2(TRPP2)/ PERK / e IF2α signaling pathways,and further explore the important role of ACC in head and neck squamous cell carcinoma(HNSCC).Methods:We used Westernblot to study Fa Du cells pretreated with compound C(AMPK inhibitor)or AICAR(AMPK agonist)to detect phosphorylated AMPK(p-AMPK),ACC,phosphorylated ACC(p-ACC),PERK,phosphorylated PERK(p-PERK),e IF2α and phosphorylated e IF2α(p-e IF2α)expression levels.TRPP2 si RNA was used to transfect Fa Du cells to observe changes in the expression levels of AMPK,p-AMPK,ACC,p-ACC,PERK,p-PERK,e IF2α and p-e IF2α.CCK8 assay was used to detect effects on cell proliferation transfected with TRPP2 si RNA.We also further used immunohistochemical analysis and Western blot analysis to compare the expression levels of ACC in HNSCC with normal tissues,as well as the association of ACC expression levels and clinical stage,cancer cell differentiation and survival time of HNSCC patients.In addition,TUNEL staining was used to test whether transfection of ACC si RNA enhanced apoptosis of Fa Du cells.Results:1、(1)Western blotting showed up-regulation or down-regulation of the AMPK / PERK /e IF2α and AMPK / ACC signaling pathway after AMPK agonists or inhibitors used in cells.This results was consistent with previous studies;(2)Western blotting showed that TRPP2 knockdown decreased the expression levels of p-PERK and p-e IF2α,while the expression of p-AMPK and p-ACC increased;(3)CCK8 assay showed that knockdown of TRPP2 enhanced Fa Du cell proliferation,and AMPK agonists inhibited TRPP2 si RNA-mediated cell proliferation whereas AMPK inhibitor potentiated it.2、(1)Immunohistochemistry and Western blotting showed that ACC was highly expressed in laryngeal carcinoma tissues compared with adjacent normal tissues;(2)Immunohistochemistry showed that the expression level of ACC was positively correlated with the clinical stage of laryngeal cancer patients,and negatively correlated with the differentiation degree of laryngeal cancer cells;(3)Kaplan-Meier curve showed that the patients 5-year survival rate decreased with high ACC expression in laryngeal cancer;(4)Apoptosis experiments showed that knockdown of ACC enhanced apoptosis in Fa Du cells.Conclution:We found that knockdown of TRPP2 promotes Fa Du cell proliferation by inhibiting the PERK / e IF2α signaling pathway,while AMPK / ACC signaling pathway is activated by feedback to attenuate increased cell proliferation;ACC expression levels are associated with the development,progression,and prognosis of laryngeal cancer,and it may play an important role in HNSCC apoptosis.