Biology subjects

Sayin, V. I.

Publications and source records attributed to Sayin, V. I..

5 recordsLinked to original sources

bioRxiv2025

Amino acid restriction sensitizes lung cancer cells toferroptosis via GCN2-dependent activation of the integratedstress response

Lung cancer cells are vulnerable to iron-dependent oxidation of phospholipids leading to ferroptosis, a process countered by glutathione peroxidase-4 that converts lipid hydroperoxides to lipid alcohols using glutathione as reducing agent. Since ferroptosis-inducing agents are in clinical development, identifying modifiers of ferroptosis susceptibility is warranted. Here, we investigate the impact of amino acids on susceptibility to buthionine sulfoximine (BSO), a glutamate-cysteine ligase inhibitor that blocks biosynthesis of glutathione. We found that reduced amounts of amino acids other than cysteine increased the sensitivity to BSO and other ferroptosis-inducing agents, in a panel of mouse and human lung cancer cells, without affecting glutathione production. Activation of the amino acid sensor protein GCN2 and the integrated stress response lowered the threshold for lipid peroxidation by stimulating ATF4-dependent mitochondrial respiration. The finding has implications for lung cancer metabolism and raises the possibility of using protein restricted diets in combination with ferroptosis-inducing agents as cancer therapies.

cancer biology↗

bioRxiv2025

Identification of a BACH1 lung cancer signature: A novel tool for understanding BACH1 biology and identifying new inhibitors.

The transcription factor BACH1 is a transcriptional repressor with a central role in regulating oxidative stress and anti-inflammatory pathways, emerging as a promising therapeutic target for multiple conditions, including neoplastic malignancies, neurodegenerative disorders, ischemia-reperfusion injuries and sickle cell disease. In the field of cancer BACH1 has gained significant attention, with BACH1 overexpression correlating with poor prognosis and metastasis across various cancer types; however, despite this increasing relevance of BACH1, no universal pro-metastatic mechanism or transcriptional signature for BACH1 has been identified which is a major limitation for this growing field. To address this, we performed RNA-Seq coupled with ChIP-Seq in BACH1-proficient and BACH1-deficient lung cancer cells, identifying a set of common BACH1 directly regulated genes, which we thoroughly validated in a large panel of cancer cells. This novel lung cancer BACH1 transcriptional signature is highly sensitive and specific to BACH1 perturbations (both genetic and pharmacological) and does not respond to NRF2 modulation, underscoring its specificity. This signature not only represents a robust surrogate for BACH1 activity, but we also provide evidence of its potential value as a tool to i) identify novel BACH1 inhibitors, and ii) provide insights into BACH1s pro-metastatic role.

cancer biology↗

bioRxiv2024

Aging promotes lung cancer metastasis through epigenetic ATF4 induction

Lung cancer is primarily a disease of the elderly. Despite shared molecular changes between aging and cancer 1 - such as permissive chromatin states and deregulated protein homeostasis - studies on physiologically aged models of human lung cancer are lacking. Here, we show that aging alters the progression of KRAS-driven non-small cell lung cancer (NSCLC), promoting metastasis while suppressing primary lung tumor growth. Clinically, a multicenter analysis of all consecutively diagnosed NSCLC cases in Western Sweden over a 3-year period confirmed increased metastasis and smaller primary tumor size with age in KRAS-driven NSCLC. In addition, primary lung tumor cultures derived from older mice demonstrated an increased metastatic phenotype. Unbiased transcriptomic and epigenomic analyses identified ATF4, a major arm of the unfolded protein response (UPR), as a driver of aging-induced lung cancer metastasis. Furthermore, we found that the age-associated increase in ATF4 fuels metastatic dissemination through metabolic rewiring, including increased glutaminolysis. Finally, we report that pharmacological inhibition of glutaminase effectively suppressed aging-induced metastasis. Our findings suggest a novel adjuvant therapy for human lung cancer by targeting aging-induced metabolic plasticity, highlighting the need to consider the biology of aging in the development of cancer therapy.

cancer biology↗

bioRxiv2024

Nuclear RNAi Modulates Influenza A Virus Infectivity By Downregulating Type-I Interferon Response

The role of Argonaute (AGO) proteins and the RNA interference (RNAi) machinery in mammalian antiviral response has been debated. Therefore, we set out to investigate how mammalian RNAi impacts influenza A virus (IAV) infection. We reveal that IAV infection triggers nuclear accumulation of AGO2, which is directly facilitated by p53 activation. Mechanistically, we show that IAV induces nuclear AGO2 targeting of TRIM71, a proposed AGO2 E3 ligase, and type-I interferon-pathway genes for silencing. Accordingly, Tp53-/- mice do not accumulate nuclear AGO2 and demonstrate decreased susceptibility to IAV infection. Hence, the RNAi machinery is highjacked by the virus to evade the immune system and support viral replication. Furthermore, the FDA approved drug arsenic trioxide, which prevents p53 tetramerization and nuclear translocation, increases interferon response and decreases viral replication in vitro and in a mouse model in vivo. Our data indicates that targeting the AGO2:p53-mediated silencing of innate immunity may offer a promising strategy to mitigate viral infections.

biochemistry↗

bioRxiv2023

Glutamine antagonist DRP-104 suppresses tumor growth and enhances response to checkpoint blockade in KEAP1 mutant lung cancer

Loss-of-function mutations in KEAP1 frequently occur in lung cancer and are associated with resistance to standard of care treatment, highlighting the need for the development of targeted therapies. We have previously shown that KEAP1 mutant tumors have increased glutamine consumption to support the metabolic rewiring associated with NRF2 activation. Here, using patient-derived xenograft models and antigenic orthotopic lung cancer models, we show that the novel glutamine antagonist DRP-104 impairs the growth of KEAP1 mutant tumors. We find that DRP-104 suppresses KEAP1 mutant tumor growth by inhibiting glutamine-dependent nucleotide synthesis and promoting anti-tumor CD4 and CD8 T cell responses. Using multimodal single-cell sequencing and ex vivo functional assays, we discover that DRP-104 reverses T cell exhaustion and enhances the function of CD4 and CD8 T cells culminating in an improved response to anti-PD1 therapy. Our pre-clinical findings provide compelling evidence that DRP-104, currently in phase 1 clinical trials, offers a promising therapeutic approach for treating patients with KEAP1 mutant lung cancer. Furthermore, we demonstrate that by combining DRP-104 with checkpoint inhibition, we can achieve suppression of tumor intrinsic metabolism and augmentation of anti-tumor T cell responses.

cancer biology↗