Induction of serine hydroxymethyltransferase 2 promotes tumorigenesis and metastasis in neuroblastoma

Abstract

High-risk neuroblastoma (NB) remains an extremely difficult subgroup to cure and is associated with MYCN amplification. Serine hydroxymethyltransferase 2 (SHMT2) regulates serine metabolism in a myc-dependent manner; it is upregulated in several cancers and is associated with tumor aggressiveness. Akt-2, an important regulator of MYCN via the PI3K/Akt pathway, induces metastatic potential in NB. The association between SHMT2 and PI3K/Akt in hepatocyte regeneration has been well established but its mechanistic interaction in cancer has yet to be clearly elucidated. Herein, we evaluated the exact role of SHMT2 on the PI3K/Akt pathway, in addition to NB tumorigenesis and metastatic potential in vitro . SHMT2 gene expression and overall survival (OS) were assessed. Two human NB cell lines were examined. SHMT2 silencing and overexpression were performed. The downstream effects were analyzed with immunoblotting, RT-qPCR and functional assays were performed. We found SHMT2 gene expression is associated with decreased OS and MYCN amplification. SHMT2 protein and mRNA expression are increased in MYCN -amplified cells. SHMT2 expression has a direct interaction with Akt-2 and MYCN . Induction of SHMT2 increased cellular proliferation, colony formation and cellular migration and SHMT2 expression was increased in metastatic NB cells. We conclude that SHMT2 regulates N-Myc via phosphorylation of Akt-2 and plays an important role in NB tumorigenesis by contributing to cell growth, migration, colony formation and metastasis in vitro .

Structure-Based Design of Transport-Specific Multitargeted One-Carbon Metabolism Inhibitors in Cytosol and Mitochondria

“…The 1 H NMR matches the 1 H NMR reported in the literature. 75 Methyl 4-((3-Iodopropyl)thio)benzoate (23). Compound 23 was prepared using the general method described for the preparation of 19a−b, 23, and 31e, from compound 22 (2.5 g, 10.40 mmol), methanesulfonyl chloride (1 mL, 13.02 mmol), and triethylamine (1.60 mL, 11.44 mmol) to form the intermediate.…”

“…Importantly, serine catabolism is frequently upregulated in cancer, with SHMT2 and MTHFD2 among the most overexpressed metabolic genes in human cancers compared to normal tissues . Indeed, studies in several cancers suggest that SHMT2 is a bona fide “onco-driver”. − Further, overexpression of SHMT2 is associated with poor prognosis in breast cancer, − lung adenocarcinoma, pancreatic cancer, gliomas, and gastrointestinal cancers . In invasive breast cancer, adrenal carcinoma, and renal cell carcinomas, SHMT2 is likewise overexpressed .…”

Combination bromo- and extraterminal domain and poly (ADP-ribose) polymerase inhibition synergistically enhances DNA damage and inhibits neuroblastoma tumorigenesis

“…Cells were collected using cell lysis buffer and denatured samples were prepared for immunoblotting, as we have previously described [23,24]. Equal amounts of protein were loaded and separated by NuPAGE 4-12% Bis-Tris gel, followed by transfer onto PVDF membranes (Bio-Rad, Hercules, CA, USA).…”

Structural Characterization of 5-Substituted Pyrrolo[3,2-d]pyrimidine Antifolate Inhibitors in Complex with Human Serine Hydroxymethyl Transferase 2

“…Serine hydroxymethyltransferase (SHMT) 2 (Uniprot entry Q150818) is a 5′-pyridoxal phosphate (PLP)-associated enzyme that catalyzes the conversion of serine to glycine in mitochondria, resulting in generation of 5,10-methylene tetrahydrofolate (mTHF) from THF (Figure ). SHMT2 is among the most overexpressed metabolic enzymes in a variety of cancers, and SHMT2 expression is widely associated with tumor progression − and patient prognosis (e.g., breast cancer, nonsmall lung cancer, pancreatic cancer). ,,− SHMT2 generates ∼85% of cellular glycine required for synthesis of glutathione, purines, proteins, and porphyrins; the mitochondrial 1C pathway supplies the majority of 1C units (as formate) for cellular biosynthesis in the cytosol. ,− , Further, mitochondrial 1C metabolism from serine is also an important source of NAD­(P)H and generates ATP. , Finally, loss of SHMT2 results in defective mitochondrial respiration due to impaired synthesis of respiratory chain proteins. , …”