SLC6A14 Depletion Contributes to Amino Acid Starvation to Suppress EMT-Induced Metastasis in Gastric Cancer by Perturbing the PI3K/AKT/mTORC1 Pathway

Biomed Res Int. 2022 Jul 12:2022:7850658. doi: 10.1155/2022/7850658. eCollection 2022.

Abstract

Metastasis is the main obstacle for the treatment of gastric cancer (GC), leading to low survival rate and adverse outcomes in CG patients. SLC6A14, a general amino acid transporter, can import all the essential amino acids in a manner dependent on the NaCl-generated osmotic gradients. Herein, we constructed GC cell sublines with high (SGC7901-M and MKN28-M) and low (MKN28-NM and SGC7901-NM) metastatic ability. Putative functional genes advancing GC metastasis were identified using mRNA microarray analysis and High-Content Screening. In particular, most significant change with a dampening trend in the migration potentiality of GC cells emerged after SLC6A14 gene was silenced. SLC6A14 expression was positively correlated with the migrated capability of different GC cell lines, and SLC6A14 was also constitutively expressed in GC patients with venous or lymphatic invasion, lymph node, or distant metastasis and poor prognosis, thus prompting SLC6A14 as a nonnegligible presence in supporting GC migration and invasion. Consistently, SLC6A14 depletion drastically depressed GC metastasis in vitro and in vivo. Most importantly, pharmacological blockade and gene silence of SLC6A14 both restricted epithelial-mesenchymal transition- (EMT-) driven GC metastasis, in which attenuated activation of the PI3K/AKT/mTORC1 pathway caused by amino acid starvation was involved. In summary, it is conceivable that targeting SLC6A14 has a tremendous promising for the treatment of metastatic GC.

MeSH terms

  • Amino Acid Transport Systems* / genetics
  • Amino Acids / metabolism
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Epithelial-Mesenchymal Transition / genetics
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Mechanistic Target of Rapamycin Complex 1 / genetics
  • Mechanistic Target of Rapamycin Complex 1 / metabolism
  • Neoplasm Invasiveness / genetics
  • Phosphatidylinositol 3-Kinases / genetics
  • Phosphatidylinositol 3-Kinases / metabolism
  • Proto-Oncogene Proteins c-akt / genetics
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction
  • Stomach Neoplasms* / pathology

Substances

  • Amino Acid Transport Systems
  • Amino Acids
  • SLC6A14 protein, human
  • Mechanistic Target of Rapamycin Complex 1
  • Proto-Oncogene Proteins c-akt