bims-stacyt 2025-06-01 papers

Front Cell Dev Biol. 2025 ;13 1572909

Hypoxia-driven angiogenesis and metabolic reprogramming in vascular tumors.

Lu Liu, Jiayun Yu, Yang Liu, Liang Xie, Fan Hu, Hanmin Liu.

Hypoxia is a hallmark of the tumor microenvironment (TME), and it plays a crucial role in the occurrence and progression in vascular tumors. Under hypoxic conditions, hypoxia-inducible factor 1-alpha (HIF-1α) is stabilized, inducing changes in the expression of various target genes involved in angiogenesis, metabolism, and cell survival. This includes the upregulation of pro-angiogenic factors like VEGF, which promotes the formation of dysfunctional blood vessels, contributing to the worsening of the hypoxic microenvironment. At the same time, hypoxia induces a metabolic shift toward glycolysis, even in the presence of oxygen, supporting tumor cell survival and proliferation by providing necessary energy and biosynthetic precursors. This review discusses the molecular mechanisms by which hypoxia regulates angiogenesis and metabolic reprogramming in vascular tumors, highlighting the intricate link between these processes, and explores potential therapeutic strategies to target these pathways in order to develop effective treatment strategies for patients.

Keywords: HIF-1α; angiogenesis; hypoxia; metabolic reprogramming; tumor microenvironment; vascular tumors

DOI: https://doi.org/10.3389/fcell.2025.1572909

Int J Mol Sci. 2025 May 20. pii: 4900. [Epub ahead of print]26(10):

Inhibition of MCP1 (CCL2) Enhances Antitumor Activity of NK Cells Against HCC Cells Under Hypoxia.

Hwan Hee Lee, Juhui Kim, Eunbi Park, Hyojeung Kang, Hyosun Cho.

Hypoxia, a low-oxygen state, is a common feature of solid tumors. MCP1 (CCL2) is a small cytokine that is closely related to hypoxia and has a positive effect on tumor development. Hypoxia causes resistance to various treatments for solid tumors and the evasion of cancer immune surveillance by lymphocytes. Natural killer (NK) cells are innate lymphocytes that play an important role in cancer development, particularly in the liver. First, it was found that the incubation of HCC in hypoxia (2-5% O2) significantly increased the production of several inflammatory cytokines, including MCP1, compared to that of normal oxygen (20% O2). Subsequently, blocking MCP1 with an anti-MCP1 antibody in HCC cultures inhibited the growth and migration of HCC cells in vitro and in vivo. This was associated with a decrease in the expression of HIF-1α/STAT3 in HCC under hypoxia. Furthermore, blocking MCP1 in HCC cell cultures under hypoxia significantly increased the chemotaxis and activation of NK-92 cells against HCC cells. MCP1 blockade in HCC cell cultures under hypoxia induced a shift in NK cells to the CD56+dim population and an increase in the expression of the activation receptors NKG2D and NKp44. In conclusion, modulation of MCP1 could enhance NK activity against hypoxic HCC cells.

Keywords: MCP1 (CCL2); human hepatocellular carcinoma (HCC); hypoxia; natural killer (NK) cell; tumor microenvironment

DOI: https://doi.org/10.3390/ijms26104900

Neuro Oncol. 2025 May 27. pii: noaf128. [Epub ahead of print]

Polyamine acetylation mediates crosstalk between cancer cells and myeloid cells to promote mesenchymal/plurimetabolic states in glioblastoma.

Ayush B Rana, Timothy M Horton, Vijay S Thakur, Dazhi Wang, Varsha Thakur, Molly Dalzell, Juliano T Freitas, Durga Prasad Gannamedi, Ifeanyichukwu Ogobuiro, Barbara Bedogni, Sakir H Gultekin, Timothy J Garrett, Alejandro V Villarino, Jun Lu, David B Lombard, Ashish H Shah, Scott M Welford.

BACKGROUND: Metabolic reprogramming in glioblastoma (GBM) is a putative determinant of GBM subtype, malignant cell state and tumor-immune crosstalk. In the present study, we investigated how polyamine metabolic rewiring contributes to the malignant cell-intrinsic and microenvironment-dependent biological processes underpinning GBM subtype classification.
METHODS: Liquid chromatography/tandem mass spectrometry (LC-MS/MS) was used for polyamine quantification in human and murine GBM tumors and cell lines. Through single-cell RNA sequencing, metabolic profiling and additional functional experiments, we dissect the malignant cell-intrinsic and paracrine signaling processes regulated by SAT1 (spermidine/spermine-N1-acetyltransferase1) and its product, N1-acetylspermidine.
RESULTS: We find that polyamine acetylation is elevated in human and murine GBM tumors and contributes to the classification of mesenchymal/plurimetabolic GBM through both regulation of tumor-cell intrinsic glucose metabolism and by facilitating metabolic crosstalk with tumor-associated macrophages/myeloid cells (TAMs). The impact of SAT1 on tumor cell metabolism is mediated, at least in part, by N1-acetylspermdine, the sole polyamine elevated in human and murine tumors. Furthermore, the relatively high levels of N1-acetylspermidine released by GBM is taken up by myeloid cells to promote intracellular polyamine flux, cellular respiration and migration. In vivo, both genetic disruption of polyamine acetylation and pharmacological inhibition of polyamine transport reduced myeloid cell infiltration and sensitized tumors to chemoradiation.
CONCLUSIONS: Collectively, the findings highlight a previously unidentified role for SAT1 and its product, N1-acetylspermidine, in bridging the metabolic activity of tumor cells and tumor-associated macrophages/myeloid cells (TAMs), together promoting mesenchymal/plurimetabolic states and therapeutic resistance in GBM.

Keywords: Glioblastoma; immune; mesenchymal phenotype; metabolism; polyamines

DOI: https://doi.org/10.1093/neuonc/noaf128

Blood. 2025 May 28. pii: blood.2024027846. [Epub ahead of print]

PERK Maintains Hematopoietic Stem Cell Pool Integrity under Endoplasmic Reticulum Stress by Promoting Proliferation.

Manxi Zheng, Qinlu Peng, Erin M Kropp, Zhejuan Shen, Suxuan Liu, Zhengyou Yin, Sho Matono, Takao Iwawaki, Xiang Wang, Ken Inoki, Yang Mei, Qing Li, Lu Liu.

The integrity of the hematopoietic stem cell (HSC) pool depends on effective long-term self-renewal and the timely elimination of damaged or differentiation-prone HSCs. While the PERK branch of the unfolded protein response (UPR) has been shown to initiate pro-apoptotic signaling in response to ER stress in vitro, its role in regulating HSC fate in vivo remains incompletely understood. Here, we demonstrate that PERK is dispensable for steady-state hematopoiesis and HSC self-renewal under homeostatic conditions. However, under ER stress induced by disruption of ER-associated degradation (ERAD), via knockout of key components such as Sel1L or Hrd1, PERK becomes activated and drives HSC proliferation and depletion. Notably, deletion of PERK or expression of a kinase-dead PERK mutant significantly rescues the HSC defects caused by Sel1L or Hrd1 loss. Mechanistically, ERAD deficiency does not lead to increased HSC apoptosis or elevated reactive oxygen species (ROS), and PERK knockout has minimal impact on HSC apoptosis. Instead, PERK activation promotes aberrant mTOR signaling and HSC hyperproliferation, ultimately compromising self-renewal capacity. This PERK-driven elimination of stressed HSCs may function as a protective mechanism to maintain overall HSC pool integrity. Collectively, our findings reveal a previously unrecognized, proliferative, and apoptosis-independent role for PERK in regulating HSC fate under ER stress, highlighting a novel mechanism for preserving HSC homeostasis.

DOI: https://doi.org/10.1182/blood.2024027846