Transketolase promotes osteosarcoma progression through the YY1-PAK4 axis

Osteosarcoma, a malignant bone tumor that occurs in adolescents, proliferates and is prone to pulmonary metastasis. Osteosarcoma is characterized by high genotypic heterogeneity, making it difficult to identify reliable anti-osteosarcoma targets. The genotype of osteosarcoma may be highly dynamic, but its high dependence on energy remains constant. Fortunately, tumors tend to have relatively consistent metabolic types. Targeting metabolism with anti-tumor therapies is a new strategy for treating tumors. Genes related to carbohydrate metabolism are widely and highly expressed in tumor tissues. Transketolase (TKT), a key enzyme at the non-oxidative stage of the pentose phosphate pathway, is up-regulated in various tumors. In the present study, TKT promoted osteosarcoma cell proliferation non-metabolically. Specifically, TKT bound directly to amino acid residues of Yin Yang 1 (YY1) at amino acids 201-228, stimulating YY1 to bind to the promoter of P21 activated kinase 4 (PAK4) and resulting in PAK4 expression and activation of the phosphoinositide 3-kinase-Akt signaling pathway. Additionally, we designed a peptide, YY1-PEP, based on the exact mechanism of how TKT promotes osteosarcoma. Per in vivo and in vitro experiments, YY1-PEP displayed anti-osteosarcoma properties. The present study provides a new feasible strategy against osteosarcoma progression.