1. ASPSCR1::TFE3-mediated upregulation of insulin receptor substrate 2 (IRS-2) activates PI3K/AKT signaling and promotes malignant phenotype.
- Author
-
Ishiguro N and Nakagawa M
- Subjects
- Humans, Cell Line, Tumor, Gene Expression Regulation, Neoplastic, Cell Movement genetics, Cell Proliferation, Phenotype, Carcinoma, Renal Cell genetics, Carcinoma, Renal Cell pathology, Carcinoma, Renal Cell metabolism, Kidney Neoplasms pathology, Kidney Neoplasms genetics, Kidney Neoplasms metabolism, Oncogene Proteins, Fusion genetics, Oncogene Proteins, Fusion metabolism, Sarcoma, Alveolar Soft Part pathology, Sarcoma, Alveolar Soft Part genetics, Sarcoma, Alveolar Soft Part metabolism, Intracellular Signaling Peptides and Proteins, Insulin Receptor Substrate Proteins metabolism, Insulin Receptor Substrate Proteins genetics, Proto-Oncogene Proteins c-akt metabolism, Proto-Oncogene Proteins c-akt genetics, Basic Helix-Loop-Helix Leucine Zipper Transcription Factors metabolism, Basic Helix-Loop-Helix Leucine Zipper Transcription Factors genetics, Signal Transduction, Phosphatidylinositol 3-Kinases metabolism, Phosphatidylinositol 3-Kinases genetics, Up-Regulation
- Abstract
The ASPSCR1::TFE3 fusion gene, resulting from chromosomal translocation, is detected in alveolar soft part sarcoma (ASPS) and a subset of renal cell carcinomas (RCC). The ASPSCR1::TFE3 oncoprotein, functioning as an aberrant transcription factor, contributes to tumor development and progression by inappropriately upregulating target genes. Here, we identified insulin receptor substrate 2 (IRS-2), a cytoplasmic adaptor protein, as a novel transcriptional target of ASPSCR1::TFE3. Ectopic expression of ASPSCR1::TFE3 led to increased IRS-2 mRNA and protein levels. Chromatin immunoprecipitation and luciferase assays demonstrated that ASPSCR1::TFE3 bound to the IRS-2 promoter region and enhanced its transcription. Moreover, IRS-2 was highly expressed in the ASPSCR1::TFE3-positive RCC cell line FU-UR1, while small interfering RNA-mediated depletion of ASPSCR1::TFE3 markedly decreased IRS-2 mRNA and protein levels. Functionally, IRS-2 knockdown attenuated activation of the PI3K/AKT pathway and reduced proliferation, migration, invasion, adhesion, and clonogenicity in FU-UR1 cells. Pharmacological inhibition of IRS-2 also reduced AKT activation as well as cell viability, clonogenicity, migration, invasion, and adhesion. These findings suggest that IRS-2, regulated by ASPSCR1::TFE3, promotes tumor progression by activating PI3K/AKT signaling and enhancing the malignant phenotype., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
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