The Mechanism Research Of TKT Promoting Osteosarcoma Proliferation Through YY1 Activation Of PI3K-AKT Signaling Pathway

Objective: To explore the role of the TKT who is the key enzyme in the pentose phosphate pathway in the occurrence and development of osteosarcoma and its mechanism.Methods: Firstly,the expression of metabolic enzyme TKT in osteosarcoma was detected in surgical specimen from the paitent in Wuhan union hospital and tissue chips from company.The relationship between TKT and the prognosis of patients with osteosarcoma was also explored by using bioinformatics technology in online webside tools(http://gepia.cancer-pku.cn/).Secondly,gene knockdown and overexpression technology was used to explore which biological behaviors of osteosarcoma cells are affected by TKT in vivo and in vitro experiments.Then,RNA-seq technology and Western blotting was further used to to verify the signaling pathway through which TKT leads to the enhancement of osteosarcoma biological behavior;And then,CO-IP MS and GST-pull down technology explore which proteins TKT can directly bind to,and the relevant assembly sites;Once the relevant signal transduction axis was established,the next step is verified by the Rescue experiment.Finally,some small molecular compounds or peptides are designed to interfere with the signal transduction of TKT for inhibiting the activation of related signaling pathways and achieving the purpose of inhibiting the proliferation of osteosarcoma cells,which provided a certain theoretical basis for the treatment of osteosarcoma.Results: Bioinformatics analysis and clinical specimen verification confirmed that TKT was highly expressed in osteosarcoma tissues,which was significantly associated with poor prognosis in sarcoma patients.Then,it was found that,in vitro and in vivo experiments,the highly expressed TKT activated the function of YY1 by binding to the amino acid sequence 201-228 on the YY1 protein,promoted the binding of YY1 to the promoter of PAK4,and resulted in the high translation and expression of PAK4.High expression of PAK4 activates the PI3K-AKT signaling pathway in a non-metabolic manner.Finally,according to the binding site of TKT and YY1,a small peptide YY1-PEP was designed to block the binding of TKT to YY1,inhibit the expression of PAK4 and the activation of PI3K-AKT signaling pathway.Conclusion: The metabolic enzyme TKT activates the PI3K-AKT signaling pathway through the YY1-PAK4 signaling axis in a non-metabolic manner,which provides a theoretical basis for the treatment of osteosarcoma.