bims-aspsyn 2025-08-10 papers

J Exp Clin Cancer Res. 2025 Aug 08. 44(1): 231

CCT196969 inhibits TNBC by targeting the HDAC5/RXRA/ASNS axis to down-regulate asparagine synthesis.

Qiong Yuan, Qi Wang, Jun Li, Liyang Yin, Shu Liu, Xuyu Zu, Yingying Shen.

BACKGROUND: Triple-negative breast cancer (TNBC) seriously threatens the health of patients, and new therapeutic targets and drugs need to be explored. Studies have shown that CCT196969 can inhibit melanoma and colorectal cancer. However, the role of CCT196969 in TNBC is unclear.
METHODS: CCT196969 inhibited TNBC via in vitro and in vivo experiments. Transcriptomic analysis, metabolomics analysis, proteomic analysis, and other experiments were used to determine that CCT196969 inhibited asparagine synthetase (ASNS) expression and downstream mTOR signaling pathway, and that Retinoid X Receptor Alpha (RXRA) was the upstream transcription factor that regulated ASNS. The binding sites of RXRA and ASNS promoter were determined by luciferase and Chromatin Immunoprecipitation (CHIP) assay. Histone Deacetylase 5 (HDAC5) was confirmed as the key target of CCT196969 by target capture assay, Cell thermal shift assay (CETSA), Surface plasmon resonance (SPR) and other experiments. qPCR, CHX tracer, MG132, immunofluorescence (IF) and Co-Immunoprecipitation (CO-IP) assay were used to detect the regulation of HDAC5 on RXRA transcription and post-translation level, and the key domains of interaction and binding between HDAC5 and RXRA. The binding sites of HDAC5 and RXRA were predicted by PyMOL software. The effect of HDAC5 on the acetylation and ubiquitination levels of RXRA was examined by CO-IP experiment. The deacetylation site of HDAC5 to RXRA was investigated by IP experiments and mass spectrometry.
RESULTS: This study reveals that CCT196969 can inhibit TNBC by down-regulating the expression of ASNS, inhibiting asparagine synthesis and downstream mTORC pathway. Mechanistically, CCT196969 targeted and inhibited HDAC5, reducing the interaction of its 1-291 region with RXRA's 1-98 region, and further resulting in an increase in RXRA acetylation (K410 and K412) and a decrease in ubiquitination levels. Together, these effects up-regulated the transcriptional and post-translational levels of RXRA. Finally, RXRA inhibited the expression of ASNS at the transcriptional level by binding to the - 1114/-1104 region on the ASNS promoter as a transcription suppressor.
CONCLUSIONS: This study reveals a previously unrecognized anti-TNBC mechanism of CCT196969 through the HDAC5/RXRA/ASNS axis. This provides potential candidate targets for the treatment of TNBC and a theoretical basis for the clinical treatment of TNBC patients with CCT196969.

Keywords: Asparagine; CCT196969; HDAC5; RXRA; TNBC

DOI: https://doi.org/10.1186/s13046-025-03494-5

Sci Rep. 2025 Aug 08. 15(1): 28994

The therapeutic potential of pegylated arginase I treatment in glioblastoma.

Marcus Kwong Lam Fung, Shing Chan, Stella Sun, Ping De Zhang, Gilberto Ka Kit Leung, Godfrey Chi Fung Chan.

This study used in vitro experiments and an orthotopic glioblastoma (GBM) mouse model to test the efficacy of human pegylated arginase I formulation, BCT-100, against the incurable cancer, GBM. Arginine auxotrophy in GBM was verified in silico and in vitro by absence of OTC and ASS1 expression. BCT-100 inhibited growth and induced cell death in four GBM cell lines in vitro. Transcriptomics of U87 and U373 treated with BCT-100 responded differently. BCT-100-treated U87 showed autophagy induction. Cytotoxicity enhancement was observed in four cell lines treated with BCT-100 + chloroquine (CQ). CQ + BCT-100 induced caspase-dependent and caspase-independent cell death in luciferase-transfected U87 (U87(lf+)). BCT-100 or CQ monotherapy, but not BCT-100+ CQ, prolonged survival of intracranial U87(lf+)-bearing mice similarly without suppressing tumor growth. Mouse microglia cell BV2 protected U87(lf+) from BCT100-induced cytotoxicity in transwell co-culture. Etoposide suppressed BV2's protection to U87(lf+) upon BCT-100 treatment by suppressing the growth and inducing cell death of BV2, suggesting microglial suppression as a strategy for enhancing the efficacy of BCT-100. Microglial protection may explain the in vitro and in vivo discrepancies. Further investigation into microglia/GBM interactions may help improve the efficacy of arginine deprivation therapy against GBM.

Keywords: Arginine deprivation; Combination therapy; Glioblastoma; Microglia; Pegylated arginase I; Tumor microenvironment

DOI: https://doi.org/10.1038/s41598-025-13882-8

Redox Biol. 2025 Aug 05. pii: S2213-2317(25)00326-X. [Epub ahead of print]86 103813

Asparagine synthetase modulates glutaminase inhibitor sensitivity through metabolic reprogramming and serves as a prognostic biomarker in hepatocellular carcinoma.

Benjian Gao, Dongning Zheng, Hong Liu, Yu Guo, Yuntao Ye, Zhou Chen, Fengyi Yang, Jie Liu, Guangnian Zhang, Guoying Feng, Yongfa Liu, Qiang Wang, Song Su, Xiaoli Yang, Bo Li.

Glutamine addiction represents a metabolic vulnerability in hepatocellular carcinoma (HCC), making glutaminase inhibitor CB-839 therapy a promising approach. However, effective therapeutic strategies are not yet available. In this study, we aim to investigate the potential role of asparagine synthetase (ASNS) as a target for HCC therapy during CB-839 treatment. CB-839 suppressed HCC cell growth, triggered apoptosis, and induced oxidative stress along with the disruption of amino acid metabolism. Moreover, ASNS was induced by CB-839 treatment through the activation of the amino acid response pathway. ASNS was significantly upregulated in HCC tumor tissues and was positively associated with poor prognosis; indeed our results revealed that its overexpression facilitated the proliferation, migration, and invasion of HCC cells. Furthermore, ASNS increased glutaminolysis and glutathione synthesis through reprogramming glutamine metabolism to maintain intracellular redox homeostasis, thereby activating the mTOR pathway that contributed to HCC progression. ASNS knockdown sensitized HCC cells to CB-839 both in vitro and in vivo. Overall, ASNS modulated the sensitivity to CB-839 in HCC through metabolic reprogramming, potentially serving as a biomarker for CB-839 response and a promising therapeutic target for HCC.

Keywords: Asparagine synthetase; CB-839; Glutamine metabolism; Hepatocellular carcinoma; Metabolic reprogramming

DOI: https://doi.org/10.1016/j.redox.2025.103813

bioRxiv. 2025 Aug 01. pii: 2025.07.29.667471. [Epub ahead of print]

Alanine Catabolism as a Targetable Vulnerability for MYC-Driven Liver Cancer.

Tonatiuh Montoya, Joyce V Lee, Longhui Qiu, Abigail Krall, Nedas Matulionis, Yurim Seo, Brian N Finck, Robin K Kelley, Heather Christofk, Andrei Goga.

Liver cancer is a leading cause of cancer-related death world-wide in part due to the shortage of effective therapies, and MYC overexpression defines an aggressive and especially difficult to treat subset of patients. Given MYC's ability to reprogram cancer cell metabolism, and the liver's role as a coordinator of systemic metabolism, we hypothesized that MYC induces metabolic dependencies that could be targeted to attenuate liver tumor growth. We discovered that MYC-driven liver cancers catabolize alanine in a GPT2-dependent manner to sustain their growth. GPT2 is the predominant alanine-catabolizing enzyme expressed in MYC-driven liver tumors and genetic ablation of GPT2 limited MYC-driven liver tumorigenesis. In vivo isotope tracing studies uncovered a role for alanine as a substrate for a repertoire of pathways including the tricarboxylic acid cycle, nucleotide production, and amino acid synthesis. Treating transgenic MYC-driven liver tumor mouse models with L-Cycloserine, a compound that inhibits GPT2, was sufficient to diminish the frequency of mouse tumor formation and attenuate growth of established human liver tumors. Thus, we identify a new targetable metabolic dependency that MYC-driven liver tumors usurp to ensure their survival.

DOI: https://doi.org/10.1101/2025.07.29.667471