Identification of a novel PHGDH covalent inhibitor by chemical proteomics and phenotypic profiling

The first rate-limiting enzyme of the serine synthesis pathway (SSP), phosphoglycerate dehydrogenase (PHGDH), is hyperactive in multiple tumors, which leads to the activation of SSP and promotes tumorigenesis. However, only a few inhibitors of PHGDH have been discovered to date, especially the covalent inhibitors of PHGDH. Here, we identified withangulatin A (WA), a natural small molecule, as a novel covalent inhibitor of PHGDH. Affinity-based protein profiling identified that WA could directly bind to PHGDH and inactivate the enzyme activity of PHGDH. Biolayer interferometry and LC-MS/MS analysis further demonstrated the selective covalent binding of WA to the cysteine 295 residue (Cys295) of PHGDH. With the covalent modification of Cys295, WA blocked the substrate-binding domain (SBD) of PHGDH and exerted an allosteric effect to induce PHGDH inactivation. Further studies revealed that with the inhibition of PHGDH mediated by WA, the glutathione synthesis was decreased and intracellular levels of reactive oxygen species (ROS) were elevated, leading to the inhibition of tumor proliferation. This study indicates WA as a novel PHGDH covalent inhibitor, which identifies Cys295 as a novel allosteric regulatory site of PHGDH and holds great potential in developing anti-tumor agents for targeting PHGDH.

Reversing malignant biological behavior of osteosarcoma by knocking down 3-phosphoglycerin dehydrogenase targeting energy metabolism / 解剖学报

Objective To investigate the effect of knock⁃down 3⁃phosphoglycerin dehydrogenase (PHGDH) targeting energy metabolism on malignant biological behavior and osteogenic differentiation of human osteosarcoma 143B cells. Methods Real⁃time PCR and Western blotting were used to detect the expression of PHGDH in osteoblasts hFOB1. 19 and osteosarcoma cells TE85, MG63 and 143B with different malignant degrees. The short hairpin RNA (shRNA)⁃PHGDH recombinant plasmid was transfected into 143 B cells by liposome transfection method. The expression of PHGDH was detected by Real⁃time PCR and Western blotting. Crystal violet staining, cell counting and CCK⁃8 assay were used to detect cell proliferation; wound healing assay was used to detect cell parallel migration ability, and Transwell assay was used to detect cell vertical migration and invasion ability. Annexin V⁃FITC/ PI double staining and DAPI staining were used to detect apoptosis; Alkaline phosphatase(ALP) staining and alizarin red S staining were used to detect osteogenic differentiation. Western blotting was used to detect the expression of Runt related transcription factor 2 (Runx2) and osteocalcin (OC) . The expression of genes related to energy metabolism, glucose transporter⁃1 (GLUT1), 6⁃ phosphofructokinase⁃1(PFK1), pyruvate kinae subtype M2 (PKM2), lactate dehydrogenase A (LDHA) was detected by Real⁃time PCR. Lactic acid secretion was detected by lactic acid detection kit. Adenosine triphosphate(ATP) production was detected by ATP detection kit. Results The expression of PHGDH in 143B cells was significantly higher than that in hFOB1. 19, MG63 and TE85 cells (P < 0. 01) . After the transfection of shRNA⁃PHGDH recombinant plasmid, the expression of PHGDH in 143 B cells decreased (P<0. 01), proliferation ability decreased (P<0. 01), cell migration and invasion ability decreased (P < 0. 01), apoptosis rate increased (P < 0. 01), ALP staining positive rate increased (P < 0. 01), alizarin red staining positive rate increased (P < 0. 05), Runx2 (P < 0. 05) and OC expression increased (P < 0. 01), expression of genes related to energy metabolism (GLUT1, PFK1, PKM2, LDHA) decreased (P < 0. 01), lactic acid decreased (P < 0. 01), ATP increased (P < 0. 05) . Conclusion Knocking down of PHGDH can inhibit the proliferation, migration and invasion of human osteosarcoma 143B cells through energy metabolism, promote their apoptosis and promote their osteogenic differentiation.

Role of phosphoglycerate mutase 1 in the occurence and development of tumor / 上海交通大学学报（医学版）

Phosphoglycerate mutase 1 (PGAM1) as one of the most important enzymes for glycolysis pathway,is highly expressed in multiple tumor tissues and negatively correlated with the prognosis of cancer patients.PGAM1 catalyzes the conversion of 3-phosphoglycerate (3-PG) to 2-phosphoglycerate (2-PG) in glycolysis pathway,then promoting anabolic pathways,energy generation,and maintaining redox balance during cancer cell proliferation and metastasis.The small molecule PGAM1 inhibitors have emerged as a promising strategy for anti-tumor therapy.In this review,the significance of PGAM1 in tumor was reviewed and the research progress of PGAM1 inhibitors was also introduced.

Role of phosphoglycerate mutase 1 in the occurence and development of tumor / 上海交通大学学报（医学版）

Phosphoglycerate mutase 1 (PGAM1) as one of the most important enzymes for glycolysis pathway, is highly expressed in multiple tumor tissues and negatively correlated with the prognosis of cancer patients. PGAM1 catalyzes the conversion of 3-phosphoglycerate (3-PG) to 2-phosphoglycerate (2-PG) in glycolysis pathway, then promoting anabolic pathways, energy generation, and maintaining redox balance during cancer cell proliferation and metastasis. The small molecule PGAM1 inhibitors have emerged as a promising strategy for anti-tumor therapy. In this review, the significance of PGAM1 in tumor was reviewed and the research progress of PGAM1 inhibitors was also introduced.