Inhibition of GLS1 and ASCT2 Synergistically Enhances the Anticancer Effects in Pancreatic Cancer Cells

Area of Science:

• Oncology
• Cancer Metabolism
• Molecular Biology

Background:

• Pancreatic cancer relies heavily on glutamine metabolism.
• Glutaminase (GLS) inhibitors like telaglenastat (CB-839) show limited efficacy alone due to metabolic adaptations.
• The general control nonderepressible 2 (GCN2)-activating transcription factor 4 (ATF4) pathway is activated by CB-839 treatment.

Purpose of the Study:

• To investigate the role of ATF4 in pancreatic cancer's metabolic response to glutaminase inhibition.
• To evaluate the therapeutic potential of combining GLS and ASCT2 inhibition.

Main Methods:

• Cell growth inhibition assays with CB-839.
• ATF4 knockdown experiments.
• Assessment of glutamine transporter expression and uptake.
• Combination therapy studies with CB-839 and ASCT2 inhibitor V-9302.

Main Results:

• CB-839 inhibited pancreatic cancer cell growth but induced ATF4 activation.
• ATF4 knockdown decreased ASCT2 expression, glutamine uptake, and cell viability under stress.
• Combined inhibition of GLS and ASCT2 demonstrated synergistic effects on pancreatic cancer cell survival.

Conclusions:

• ATF4 plays a protective role in pancreatic cancer by regulating glutamine metabolism.
• Dual inhibition targeting GLS and ASCT2 represents a potential therapeutic strategy for pancreatic cancer.
• Targeting ATF4 and ASCT2 could overcome resistance to GLS inhibitors.