# SLC6A14-mediated glutamine promotes SYTL4–CXCL8 axis activation to drive gemcitabine resistance and immune evasion in pancreatic cancer

## TL;DR

This study shows that the protein SLC6A14 helps pancreatic cancer cells resist treatment and avoid immune detection by using glutamine, suggesting it as a potential target for new therapies.

## Contribution

The study identifies SLC6A14 as a key driver of glutamine metabolism that links gemcitabine resistance and immune evasion in pancreatic cancer.

## Key findings

- SLC6A14 promotes glutamine metabolism, activating mTOR/NF-κB signaling to upregulate PD-L1 and enable immune evasion.
- Blocking SLC6A14 reduces tumor growth, metastasis, and glutamine production while enhancing gemcitabine sensitivity and immune response.
- SLC6A14-induced CXCL8 secretion activates cancer-associated fibroblasts, supporting PDAC progression through mitochondrial fission and amino acid recycling.

## Abstract

Chemoresistance remains a major challenge in pancreatic ductal adenocarcinoma (PDAC). Glutamine sustains drug resistance and shapes the immunosuppressive tumor microenvironment; however, the underlying mechanisms remain unclear. Identifying key regulators that drive both gemcitabine resistance and immune evasion is crucial for improving theapeutic outcomes in PDAC. Here we identified solute-carrier family 6 member 14 (SLC6A14) as the central regulator of glutamine metabolism that drives gemcitabine resistance. SLC6A14-mediated glutamine metabolism facilitated α-ketoglutarate production, activating mTOR/NF-κB signaling to upregulate PD-L1 expression, playing a central role in immune evasion. Moreover, SLC6A14 induced CXC motif chemokine ligand 8 secretion via synaptotagmin-like 4-mediated exocytosis, paracrinally activating CXCR2 signaling in cancer-associated fibroblasts to enhance mitochondrial fission and amino acid recycling, supporting PDAC progression. Targeting SLC6A14 with α-methyl-tryptophan enhanced gemcitabine sensitivity, suppressed PD-L1 driven immune evasion and reduced tumor growth, metastasis and glutamine production in vivo. These findings underscore SLC6A14 as a pivtoal mediator of glutamine-driven gemcitabine resistance and immune evasion in PDAC. Therapeutic strategies targeting SLC6A14, either alone or in combination with PD-L1 blockade, hold promise for overcoming chemoresistance and enhancing antitumor immunity in gemcitabine-resistant pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a deadly cancer with low survival rates, and resistance to the drug gemcitabine is a major treatment challenge. Researchers aimed to understand how the tumor environment contributes to this resistance. The study focused on a protein called SLC6A14, which helps transport amino acids into cells. This protein is linked to cancer progression and drug resistance. Researchers used various methods, including cell cultures and animal models, to study the role of SLC6A14 in PDAC. They found that SLC6A14 increases the uptake of glutamine, which fuels cancer cell growth and helps them evade the immune system. By blocking SLC6A14, they reduced cancer cell growth and improved immune response against the tumor. The study concludes that targeting SLC6A14 could be a promising strategy to overcome drug resistance in PDAC.

This summary was initially drafted using artificial intelligence, then revised and fact-checked by the author.