2. Academic Validation
  3. GCN2-SLC7A11 axis coordinates autophagy, cell cycle and apoptosis and regulates cell growth in retinoblastoma upon arginine deprivation

GCN2-SLC7A11 axis coordinates autophagy, cell cycle and apoptosis and regulates cell growth in retinoblastoma upon arginine deprivation

  • Cancer Metab. 2024 Oct 26;12(1):31. doi: 10.1186/s40170-024-00361-3.
Dan Wang 1,  Wai Kit Chu 2 3,  Jason Cheuk Sing Yam 2 3 4 5 6,  Chi Pui Pang 2 3,  Yun Chung Leung 7,  Alisa Sau Wun Shum 8,  Sun-On Chan 9
Affiliations

Affiliations

  • 1 School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China.
  • 2 Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China.
  • 3 Hong Kong Hub of Pediatric Excellence, The Chinese University of Hong Kong, Hong Kong SAR, China.
  • 4 Department of Ophthalmology, Hong Kong Children's Hospital, Hong Kong SAR, China.
  • 5 Hong Kong Eye Hospital, Hong Kong SAR, China.
  • 6 Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong SAR, China.
  • 7 Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong SAR, China.
  • 8 School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China. alisa-shum@cuhk.edu.hk.
  • 9 School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China. sunonchan@cuhk.edu.hk.
PMID: 39462426 DOI: 10.1186/s40170-024-00361-3
Abstract

Background: Arginine deprivation was previously shown to inhibit retinoblastoma cell proliferation and induce cell death in vitro. However, the mechanisms by which retinoblastoma cells respond to arginine deprivation remain to be elucidated.

Methods: The human-derived retinoblastoma cell lines Y79 and WERI-Rb-1 were subjected to arginine depletion, and the effects on inhibiting cell growth and survival were evaluated. This study investigated potential mechanisms, including Autophagy, cell cycle arrest and Apoptosis. Moreover, the roles of the general control nonderepressible 2 (GCN2) and mechanistic target of rapamycin complex 1 (mTORC1) signaling pathways in these processes were examined.

Results: We demonstrated that arginine deprivation effectively inhibited the growth of retinoblastoma cells in vitro. This treatment caused an increase in the autophagic response. Additionally, prolonged arginine deprivation induced G2 cell cycle arrest and was accompanied by an increase in early apoptotic cells. Importantly, arginine depletion also induced the activation of GCN2 and the inhibition of mTOR signaling. We also discovered that the activation of SLC7A11 was regulated by GCN2 upon arginine deprivation. Knockdown of SLC7A11 rendered retinoblastoma cells partially resistant to arginine deprivation. Furthermore, we found that knockdown of GCN2 led to a decrease in the autophagic response in WERI-Rb-1 cells and arrested more cells in S phase, which was accompanied by fewer apoptotic cells. Moreover, knockdown of GCN2 induced the constant expression of ATF4 and the phosphorylation of 70S6K and 4E-BP1 regardless of arginine deprivation.

Conclusions: Collectively, our findings suggest that the GCN2‒SLC7A11 axis regulates cell growth and survival upon arginine deprivation through coordinating Autophagy, cell cycle arrest, and Apoptosis in retinoblastoma cells. This work paves the way for the development of a novel treatment for retinoblastoma.

Keywords

Arginine deprivation; GCN2; Retinoblastoma; SCL7A11.

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