Histone deacetylase-10 liberates spermidine to support polyamine homeostasis and tumor cell growth

Tracy Murray Stewart, Jackson R. Foley, Cassandra E. Holbert, Glynis Klinke, Gernot Poschet, Raphael R. Steimbach, Aubry K. Miller, Robert A. Casero

Research output: Contribution to journalArticlepeer-review


Cytosolic histone deacetylase-10 (HDAC10) specifically deacetylates the modified polyamine N8-acetylspermidine (N8-AcSpd). Although intracellular concentrations of N8-AcSpd are low, extracellular sources can be abundant, particularly in the colonic lumen. Extracellular polyamines, including those from the diet and microbiota, can support tumor growth both locally and at distant sites. However, the contribution of N8-AcSpd in this context is unknown. We hypothesized that HDAC10, by converting N8- AcSpd to spermidine, may provide a source of this growth-supporting polyamine in circumstances of reduced polyamine biosynthesis, such as in polyamine-targeting anticancer therapies. Inhibitors of polyamine biosynthesis, including α-difluoromethylornithine (DFMO), inhibit tumor growth, but compensatory uptake of extracellular polyamines has limited their clinical success. Combining DFMO with inhibitors of polyamine uptake have improved the antitumor response. However, acetylated polyamines may use different transport machinery than the parent molecules. Here, we use CRISPR/Cas9-mediated HDAC10-knockout cell lines and HDAC10-specific inhibitors to investigate the contribution of HDAC10 in maintaining tumor cell proliferation. We demonstrate inhibition of cell growth by DFMO-associated polyamine depletion is successfully rescued by exogenous N8-AcSpd (at physiological concentrations), which is converted to spermidine and spermine, only in cell lines with HDAC10 activity. Furthermore, we show loss of HDAC10 prevents both restoration of polyamine levels and growth rescue, implicating HDAC10 in supporting polyamine-associated tumor growth. These data suggest the utility of HDAC10-specific inhibitors as an antitumor strategy that may have value in improving the response to polyamine-blocking therapies. Additionally, the cell-based assay developed in this study provides an inexpensive, high-throughput method of screening potentially selective HDAC10 inhibitors.

Original languageEnglish (US)
Article number102407
JournalJournal of Biological Chemistry
Issue number10
StatePublished - Oct 2022


  • N8-acetylspermidine
  • colorectal cancer
  • difluoromethylornithine (DFMO)
  • histone deacetylase-10 (HDAC10)
  • metabolism
  • microbiome
  • polyamine
  • polyamine-blocking therapy
  • spermidine
  • tumor microenvironment (TME)

ASJC Scopus subject areas

  • Molecular Biology
  • Biochemistry
  • Cell Biology


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