bims-polyam Biomed News
on Polyamines
Issue of 2020–12–13
six papers selected by
Sebastian J. Hofer, University of Graz and Alexander Ivanov, Engelhardt Institute of Molecular Biology



  1. Cell Death Dis. 2020 Dec 10. 11(12): 1045
      Eukaryotic Translation Initiation Factor 5A (EIF5A) is a translation factor regulated by hypusination, a unique posttranslational modification catalyzed by deoxyhypusine synthetase (DHPS) and deoxyhypusine hydroxylase (DOHH) starting from the polyamine spermidine. Emerging data are showing that hypusinated EIF5A regulates key cellular processes such as autophagy, senescence, polyamine homeostasis, energy metabolism, and plays a role in cancer. However, the effects of EIF5A inhibition in preclinical cancer models, the mechanism of action, and specific translational targets are still poorly understood. We show here that hypusinated EIF5A promotes growth of colorectal cancer (CRC) cells by directly regulating MYC biosynthesis at specific pausing motifs. Inhibition of EIF5A hypusination with the DHPS inhibitor GC7 or through lentiviral-mediated knockdown of DHPS or EIF5A reduces the growth of various CRC cells. Multiplex gene expression analysis reveals that inhibition of hypusination impairs the expression of transcripts regulated by MYC, suggesting the involvement of this oncogene in the observed effect. Indeed, we demonstrate that EIF5A regulates MYC elongation without affecting its mRNA content or protein stability, by alleviating ribosome stalling at five distinct pausing motifs in MYC CDS. Of note, we show that blockade of the hypusination axis elicits a remarkable growth inhibitory effect in preclinical models of CRC and significantly reduces the size of polyps in APCMin/+ mice, a model of human familial adenomatous polyposis (FAP). Together, these data illustrate an unprecedented mechanism, whereby the tumor-promoting properties of hypusinated EIF5A are linked to its ability to regulate MYC elongation and provide a rationale for the use of DHPS/EIF5A inhibitors in CRC therapy.
    DOI:  https://doi.org/10.1038/s41419-020-03174-6
  2. Cell Prolif. 2020 Dec 10. e12960
       BACKGROUND: The tumour microenvironment primarily constitutes macrophages in the form of an immunosuppressive M2 phenotype, which promotes tumour growth. Thus, the development of methodologies to rewire M2-like tumour-associated macrophages (TAMs) into the M1 phenotype, which inhibits tumour growth, might be a critical advancement in cancer immunotherapy research.
    METHODS: The expressions of IL-33 and indicators related to macrophage polarization in oesophageal squamous cell carcinoma (ESCC) tissues and peripheral blood mononuclear cell (PBMC)-derived macrophages were determined. Inhibition of ornithine decarboxylase (ODC) with small interfering RNA was used to analyse the phenotype of macrophage polarization and polyamine secretory signals. CCK-8, wound-healing and Transwell assays were used to detect the proliferation and migration of ECA109 cells in vitro. The tumour xenograft assay in nude mice was used to examine the role of IL-33 in ESCC development in vivo.
    RESULTS: This study showed the substantially elevated IL-33 expression in ESCC tissues compared with the normal tissues. Additionally, enhanced infiltration of M2-like macrophages into the ESCC tumour tissue was also observed. We observed a strong correlation between the IL-33 levels and the infiltration of M2-like macrophages in ESCC tumours locally. Mechanistically, IL-33 induces M2-like macrophage polarization by activating ODC, a key enzyme that catalyses the synthesis of polyamines. Inhibition of ODC suppressed M2-like macrophage polarization. Finally, in vivo, we confirmed that IL-33 promotes tumour progression.
    CONCLUSIONS: This study revealed an oncogenic role of IL-33 by actively inducing M2-like macrophage differentiation; thus, contributing to the formation of an immunosuppressive ESCC tumour microenvironment. Thus, IL-33 could act as a novel target for cancer immunotherapies.
    Keywords:  IL-33; macrophage; oesophageal squamous cell carcinoma; ornithine decarboxylase
    DOI:  https://doi.org/10.1111/cpr.12960
  3. Expert Rev Neurother. 2020 Dec 09.
       BACKGROUND: Previous studies focused on food as the trigger of a migraine attack did not consider polyamines as possible activators and sensitizers of the trigeminal-vascular system through their interaction with NMDA glutamate receptors. Therefore, this study aimed to assess serum levels of nine polyamines and to evaluate their role as possible triggers and crisis maintainers in episodic and chronic migraine patients.
    MATERIALS AND METHODS: The study included 50 patients with episodic migraine (EM), 50 patients with chronic migraine (CM) and 50 healthy controls (HC). Serum levels of nine polyamines have been determined by Liquid Chromatography tandem Mass Spectrometry. Specifically, agmatine, spermidine, spermine, putrescine, cadaverine, arginine, ornithine, citrulline and lysine levels were studied.
    RESULTS: Agmatine serum levels resulted reduced in EC patients with respect to CM and HC. Compared to HC subjects, serum levels of spermine and spermidine were statistically significantly increased both in CM and EM patients.
    CONCLUSIONS: The authors suggest that alterations of polyamines levels might contribute to the understanding of migraine external activation and help to clarify the potential role of NMDA receptor polyamines site antagonists in migraine treatment.
    Keywords:  NMDA receptors; agmatine; chronic migraine; episodic migraine; polyamines; spermidine; spermine
    DOI:  https://doi.org/10.1080/14737175.2021.1862650
  4. Cancer Cell Int. 2020 Nov 05. 20(1): 539
      Polyamines are aliphatic compounds with more than two amino groups that play various important roles in human cells. In cancer, polyamine metabolism dysfunction often occurs, and regulatory mechanisms of polyamine. This review summarizes the existing research on the metabolism and transport of polyamines to study the association of oncogenes and related signaling pathways with polyamines in tumor cells. Drugs that regulate enzymes have been developed for cancer treatment, and in the future, more attention should be paid to treatment strategies that simultaneously modulate polyamine metabolism and carcinogenic signaling pathways. In addition, the polyamine pathway is a potential target for cancer chemoprevention. As an irreversible suicide inhibitor of the ornithine decarboxylase (a vital enzyme of polyamine synthesis), Difluoro-methylornithine had been shown to have the chemoprevention effect on cancer. Therefore, we summarized and analyzed the chemoprophylaxis effect of the difluoromethylornithine in this systematic review.
    Keywords:  Cancer; DFMO; Metabolism; ODC; Oncogene; Polyamine; SSAT; Signaling pathway
    DOI:  https://doi.org/10.1186/s12935-020-01545-9
  5. Plants (Basel). 2020 Dec 04. pii: E1710. [Epub ahead of print]9(12):
      Ripening of tomato fruit leads, in general, to a sequential decrease in the endogenous levels of polyamines spermidine (SPD) and spermine (SPM), while the trend for the diamine putrescine (PUT) levels is generally an initial decrease, followed by a substantial increase, and thereafter reaching high levels at the red ripe fruit stage. However, genetic engineering fruit-specific expression of heterologous yeast S-adenosylmethionine (SAM) decarboxylase in tomato has been found to result in a high accumulation of SPD and SPM at the cost of PUT. This system enabled a genetic approach to determine the impact of increased endogenous levels of biogenic amines SPD and SPM in tomato (579HO transgenic line) and on the biogenesis, transcription, processing, and stability of ribosomal RNA (rRNA) genes in tomato fruit as compared with the non-transgenic 556AZ line. One major biogenetic process regulating transcription and processing of pre-mRNA complexes in the nucleus involves small nucleolar RNAs (snoRNAs). To determine the effect of high levels of SPD and SPM on these latter processes, we cloned, sequenced, and identified a box C/D snoRNA cluster in tomato, namely, SlSnoR12, SlU24a, Slz44a, and Slz132b. Similar to this snoRNA cluster housed on chromosome (Chr.) 6, two other noncoding C/D box genes, SlsnoR12.2 and SlU24b, with a 94% identity to those on Chr. 6 were found located on Chr. 3. We also found that other snoRNAs divisible into snoRNA subclusters A and B, separated by a uridine rich spacer, were decorated with other C/D box snoRNAs, namely, J10.3, Z131a/b, J10.1, and Z44a, followed by z132a, J11.3, z132b, U24, Z20, U24a, and J11. Several of these, for example, SlZ44a, Slz132b, and SlU24a share conserved sequences similar to those in Arabidopsis and rice. RNAseq analysis of high SPD/SPM transgenic tomatoes (579HO line) showed significant enrichment of RNA polymerases, ribosomal, and translational protein genes at the breaker+8 ripening stage as compared with the 556AZ control. Thus, these results indicate that SPD/SPM regulates snoRNA and rRNA expression directly or indirectly, in turn, affecting protein synthesis, metabolism, and other cellular activities in a positive manner.
    Keywords:  RNA polymerases; RNA sequencing; polyamines; ribosomal proteins; small nucleolar RNA; snoRNA clusters; spermidine; tomato; translational proteins
    DOI:  https://doi.org/10.3390/plants9121710
  6. Infect Drug Resist. 2020 ;13 4335-4346
      A virus is an infectious particle which generally contains nucleic acid genome (DNA or RNA inside a protein shell), except for human immunodeficiency virus (HIV). Viruses have to reproduce by infecting their host cells. Polyamines are ubiquitous compounds in mammalian cells and play key roles in various cellular processes. The metabolic pathways of polyamines have been well studied. Targeting these metabolic pathways can reduce infections caused by viruses. In the study, we systematically reviewed the association of polyamine metabolic pathways and viruses including coxsackievirus B3 (CVB3), enterovirus 71 (EV71), poliovirus (PV), Zika virus (ZKV), hepatitis C virus (HCV), hepatitis B virus (HBV), dengue virus (DENV), Japanese encephalitis virus (JEV), yellow fever virus (YFV), Ebola virus (EBOV), marburgvirus (MARV), chikungunya virus (CHIKV), sindbis virus (SINV), Semliki Forest virus (SFV), Epstein-Barr virus (EBV), herpes simplex virus 1 (HSV), human cytomegalovirus (HCMV), vesicular stomatitis virus (VSV), Rabies virus (RABV), Rift Valley fever virus (RVFV), La Crosse virus (LACV), human immunodeficiency virus (HIV), Middle East respiratory syndrome virus (MERS-CoV), and coronavirus disease 2019 (SARS-CoV-2). This review revealed that targeting polyamine metabolic pathways may be a potential approach to control human viral infection.
    Keywords:  diseases; infection; polyamine metabolism; virus
    DOI:  https://doi.org/10.2147/IDR.S262024