Gene Summary

Gene:ODC1; ornithine decarboxylase 1
Aliases: ODC
Summary:This gene encodes the rate-limiting enzyme of the polyamine biosynthesis pathway which catalyzes ornithine to putrescine. The activity level for the enzyme varies in response to growth-promoting stimuli and exhibits a high turnover rate in comparison to other mammalian proteins. Originally localized to both chromosomes 2 and 7, the gene encoding this enzyme has been determined to be located on 2p25, with a pseudogene located on 7q31-qter. Multiple alternatively spliced transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, Dec 2013]
Databases:OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:ornithine decarboxylase
Source:NCBIAccessed: 01 September, 2019


What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1994-2019)
Graph generated 01 September 2019 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Stimulation, Chemical
  • Tetradecanoylphorbol Acetate
  • Messenger RNA
  • Cell Division
  • Cell Line
  • Skin Cancer
  • Breast Cancer
  • src Homology Domains
  • p38 Mitogen-Activated Protein Kinases
  • Tumor Stem Cell Assay
  • Eflornithine
  • Templates, Genetic
  • S-Adenosylmethionine
  • Retroviridae Proteins
  • Esophageal Cancer
  • Cancer Gene Expression Regulation
  • ras Proteins
  • Rectal Cancer
  • Neuroblastoma
  • Enzymologic Gene Expression Regulation
  • Chromosome 2
  • Bladder Cancer
  • Zinc Fingers
  • ODC1
  • Proto-Oncogenes
  • c-Mer Tyrosine Kinase
  • Point Mutation
  • RNA-Directed DNA Polymerase
  • beta 2-Microglobulin
  • bcl-2-Associated X Protein
  • Prostate Cancer
  • Cell Proliferation
  • Stomach Cancer
  • Uncoupling Agents
  • Cancer RNA
  • Transcription Factors
  • Colorectal Cancer
  • Transfection
  • p53 Protein
  • Risk Factors
  • Vascular Endothelial Growth Factor Receptor-2
  • Sequence Homology, Nucleic Acid
  • Species Specificity
  • Uridine
  • Retinoic Acid
Tag cloud generated 01 September, 2019 using data from PubMed, MeSH and CancerIndex

Specific Cancers (8)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: ODC1 (cancer-related)

Lam SK, U KP, Li YY, et al.
Inhibition of ornithine decarboxylase 1 facilitates pegylated arginase treatment in lung adenocarcinoma xenograft models.
Oncol Rep. 2018; 40(4):1994-2004 [PubMed] Free Access to Full Article Related Publications
Arginine depletion has shown anticancer effects among arginine auxotrophic cancers. An anti‑proliferative effect of pegylated arginase (BCT‑100) has been shown in acute myeloid leukaemia, hepatocellular carcinoma and mesothelioma. The aim of the present study was to evaluate the effect of BCT‑100 in lung adenocarcinoma. A panel of lung adenocarcinoma cell lines and xenograft models were used to investigate the effect of BCT‑100. Protein expression, arginine level, putrescine level, spermidine level and apoptosis were analyzed by western blotting, ELISA, high performance liquid chromatography, dot blot and TUNEL assay, respectively. BCT‑100 converts arginine to ornithine. BCT‑100 reduced in vitro cell viability across different lung adenocarcinoma cell lines and suppressed tumour growth in an HCC4006 xenograft, while paradoxical growth stimulation was observed in H358, HCC827, H1650 and H1975 xenografts. Upon BCT‑100 treatment, ornithine decarboxylase 1 (ODC1) was induced in two solid tumour xenografts (H1650 and H1975). It was postulated that the accumulated ornithine could be channeled via ODC1 to produce polyamines that promoted tumour growth. The action of an ODC1 inhibitor (α‑difluoromethylornithine, DFMO) was studied in the restoration of the anticancer effects of BCT‑100 in lung adenocarcinoma. In both H1650 and H1975 xenografts, a combination of DFMO and BCT‑100 significantly suppressed tumour growth, resulting in doubled median survival compared with the control. Putrescine was decreased in almost all treatment arms in the H1650, H1975 and HCC4006 xenografts. Nonetheless spermidine was reduced only following DFMO/BCT‑100 treatment in the H1650 and H1975 xenografts. Apoptosis was enhanced in the combined treatment arm in both H1650 and H1975 xenografts. In the HCC4006 xenograft, addition of DFMO did not alter the tumour suppressive effect of BCT‑100. In conclusion, inhibition of ODC1 by DFMO was crucial in facilitating BCT‑100 treatment in lung adenocarcinoma that was partially mediated by depleting arginine and polyamines with consequent apoptosis.

Fattahi S, Ghadami E, Asouri M, et al.
Urtica dioica inhibits cell growth and induces apoptosis by targeting Ornithine decarboxylase and Adenosine deaminase as key regulatory enzymes in adenosine and polyamines homeostasis in human breast cancer cell lines.
Cell Mol Biol (Noisy-le-grand). 2018; 64(3):97-102 [PubMed] Related Publications
Breast cancer is a heterogeneous and multifactorial disease with variable disease progression risk, and treatment response. Urtica dioica is a traditional herb used as an adjuvant therapeutic agent in cancer. In the present study, we have evaluated the effects of the aqueous extract of Urtica dioica on Adenosine deaminase (ADA) and Ornithine decarboxylase (ODC1) gene expression in MCF-7, MDA-MB-231, two breast cancer cell lines being estrogen receptor positive and estrogen receptor negative, respectively.  Cell lines were cultured in suitable media. After 24 h, different concentrations of the extract were added and after 72 h, ADA and ODC1 gene expression as well as BCL2 and BAX apoptotic genes were assessed by Taqman real time PCR assay. Cells viability was assessed by MTT assay, and apoptosis was also evaluated at cellular level. The intra and extracellular levels of ODC1 and ADA enzymes were evaluated by ELISA. Results showed differential expression of ADA and ODC1 genes in cancer cell lines. In MCF-7 cell line, the expression level of ADA was upregulated in a dose-dependent manner but its expression did not change in MDA-MB cell line. ODC1 expression was increased in both examined cell lines. Also, increased level of the apoptotic BAX/BCL-2 ratio was detected in MCF-7 cells. These results demonstrated that Urtica dioica induces apoptosis in breast cancer cells by influencing ODC1 and ADA genes expression, and estrogen receptors. The different responses observed with these cell lines could be due to the interaction of Urtica dioica as a phytoestrogen with the estrogen receptor.

Schultz CR, Geerts D, Mooney M, et al.
Synergistic drug combination GC7/DFMO suppresses hypusine/spermidine-dependent eIF5A activation and induces apoptotic cell death in neuroblastoma.
Biochem J. 2018; 475(2):531-545 [PubMed] Related Publications
The eukaryotic initiation factor 5A (eIF5A), which contributes to several crucial processes during protein translation, is the only protein that requires activation by a unique post-translational hypusine modification. eIF5A hypusination controls cell proliferation and has been linked to cancer. eIF5A hypusination requires the enzymes deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase and uniquely depends on the polyamine (PA) spermidine as the sole substrate. Ornithine decarboxylase (ODC) is the rate-limiting enzyme in PA biosynthesis. Both ODC and PAs control cell proliferation and are frequently dysregulated in cancer. Since only spermidine can activate eIF5A, we chose the hypusine-PA nexus as a rational target to identify new drug combinations with synergistic antiproliferative effects. We show that elevated mRNA levels of the two target enzymes DHPS and ODC correlate with poor prognosis in a large cohort of neuroblastoma (NB) tumors. The DHPS inhibitor GC7 (

Muthukumaran S, Bhuvanasundar R, Umashankar V, Sulochana KN
Insights on ornithine decarboxylase silencing as a potential strategy for targeting retinoblastoma.
Biomed Pharmacother. 2018; 98:23-28 [PubMed] Related Publications
Ornithine Decarboxylase (ODC) is a key enzyme involved in polyamine synthesis and is reported to be up regulated in several cancers. However, the effect of ODC gene silencing in retinoblastoma is to be understood for utilization in therapeutic applications. Hence, in this study, a novel siRNA (small interference RNA) targeting ODC was designed and validated in Human Y79 retinoblastoma cells for its effects on intracellular polyamine levels, Matrix Metalloproteinase 2 & 9 activity and Cell cycle. The designed siRNA showed efficient silencing of ODC mRNA expression and protein levels in Y79 cells. It also showed significant reduction of intracellular polyamine levels and altered levels of oncogenic LIN28b expression. By this study, a regulatory loop is proposed, wherein, ODC silencing in Y79 cells to result in decreased polyamine levels, thereby, leading to altered protein levels of Lin28b, MMP-2 and MMP-9, which falls in line with earlier studies in neuroblastoma. Thus, by this study, we propose ODC silencing as a prospective strategy for targeting retinoblastoma.

Kim HI, Schultz CR, Buras AL, et al.
Ornithine decarboxylase as a therapeutic target for endometrial cancer.
PLoS One. 2017; 12(12):e0189044 [PubMed] Free Access to Full Article Related Publications
Ornithine Decarboxylase (ODC) a key enzyme in polyamine biosynthesis is often overexpressed in cancers and contributes to polyamine-induced cell proliferation. We noted ubiquitous expression of ODC1 in our published endometrial cancer gene array data and confirmed this in the cancer genome atlas (TCGA) with highest expression in non-endometrioid, high grade, and copy number high cancers, which have the worst clinical outcomes. ODC1 expression was associated with worse overall survival and increased recurrence in three endometrial cancer gene expression datasets. Importantly, we confirmed these findings using quantitative real-time polymerase chain reaction (qRT-PCR) in a validation cohort of 60 endometrial cancers and found that endometrial cancers with elevated ODC1 had significantly shorter recurrence-free intervals (KM log-rank p = 0.0312, Wald test p = 5.59e-05). Difluoromethylornithine (DFMO) a specific inhibitor of ODC significantly reduced cell proliferation, cell viability, and colony formation in cell line models derived from undifferentiated, endometrioid, serous, carcinosarcoma (mixed mesodermal tumor; MMT) and clear cell endometrial cancers. DFMO also significantly reduced human endometrial cancer ACI-98 tumor burden in mice compared to controls (p = 0.0023). ODC-regulated polyamines (putrescine [Put] and/or spermidine [Spd]) known activators of cell proliferation were strongly decreased in response to DFMO, in both tumor tissue ([Put] (p = 0.0006), [Spd] (p<0.0001)) and blood plasma ([Put] (p<0.0001), [Spd] (p = 0.0049)) of treated mice. Our study indicates that some endometrial cancers appear particularly sensitive to DFMO and that the polyamine pathway in endometrial cancers in general and specifically those most likely to suffer adverse clinical outcomes could be targeted for effective treatment, chemoprevention or chemoprevention of recurrence.

Wong M, Tee AEL, Milazzo G, et al.
The Histone Methyltransferase DOT1L Promotes Neuroblastoma by Regulating Gene Transcription.
Cancer Res. 2017; 77(9):2522-2533 [PubMed] Related Publications
Myc oncoproteins exert tumorigenic effects by regulating expression of target oncogenes. Histone H3 lysine 79 (H3K79) methylation at Myc-responsive elements of target gene promoters is a strict prerequisite for Myc-induced transcriptional activation, and DOT1L is the only known histone methyltransferase that catalyzes H3K79 methylation. Here, we show that N-Myc upregulates DOT1L mRNA and protein expression by binding to the DOT1L gene promoter. shRNA-mediated depletion of DOT1L reduced mRNA and protein expression of N-Myc target genes

Choi Y, Oh ST, Won MA, et al.
Targeting ODC1 inhibits tumor growth through reduction of lipid metabolism in human hepatocellular carcinoma.
Biochem Biophys Res Commun. 2016; 478(4):1674-81 [PubMed] Related Publications
Ornithine decarboxylase 1 (ODC1), a metabolic enzyme critically involved in the polyamine biosynthesis, is commonly upregulated in hepatocellular carcinoma (HCC). Despite its altered expression in human HCC tissues, the molecular mechanism by which ODC1 alters the course of HCC progression and functions in HCC cell survival is unknown. Here we identified that silencing of ODC1 expression with small interfering (si) RNA causes inhibition of HCC cell growth through blockade of cell cycle progression and induction of apoptosis. Next, to obtain insights into the molecular changes in response to ODC1 knockdown, global changes in gene expression were examined using RNA sequencing. It revealed that 119 genes show same directional regulation (76 up- and 43 down-regulated) in both Huh1 and Huh7 cells and were considered as a common ODC1 knockdown signature. Particularly, we found through a network analysis that KLF2, which is known to inhibit PPARγ expression and adipogenesis, was commonly up-regulated. Subsequent Western blotting affirmed that the downregulation of ODC1 was accompanied by a decrease in the levels of PPARγ as well as of PARP-1, cyclin E1 and pro-caspase 9 delaying cell cycle progression and accelerating apoptotic signaling. Following the down-regulation of PPARγ expression, ODC1 silencing resulted in a strong inhibition in the expression of important regulators of glucose transport and lipid biogenesis, and caused a marked decrease in lipid droplet accumulation. In addition, ODC1 silencing significantly inhibited the growth of human HCC xenografts in nude mice. These findings indicate that the function of ODC1 is correlated with HCC lipogenesis and suggest that targeting ODC1 could be an attractive option for molecular therapy of HCC.

Zhang X, Chen Y, Hao L, et al.
Macrophages induce resistance to 5-fluorouracil chemotherapy in colorectal cancer through the release of putrescine.
Cancer Lett. 2016; 381(2):305-13 [PubMed] Related Publications
The development of chemoresistance to 5-fluorouracil (5-FU) is a major obstacle for sustained effective treatment of colorectal cancer (CRC), with the mechanisms being not fully understood. Here we demonstrated that tumor associated macrophages (TAMs) became activated during treatment with 5-FU and secreted factors that protected the CRC cells against chemotherapy with 5-FU. By performing metabolomics analysis, we identified putrescine, a member of polyamines, inducing resistance to 5-FU-triggered CRC apoptosis and tumor suppression via JNK-caspase-3 pathway. Noteworthily, either pharmacological or genetic blockage of ornithine decarboxylase (ODC) prevented TAMs-induced chemoresistance to 5-FU in vitro and in vivo. Our findings show that TAMs are potent mediators of resistance to 5-FU chemotherapy and uncover potential targets to enhance chemotherapy sensitivity in patients with CRC.

Snezhkina AV, Krasnov GS, Lipatova AV, et al.
The Dysregulation of Polyamine Metabolism in Colorectal Cancer Is Associated with Overexpression of c-Myc and C/EBPβ rather than Enterotoxigenic Bacteroides fragilis Infection.
Oxid Med Cell Longev. 2016; 2016:2353560 [PubMed] Free Access to Full Article Related Publications
Colorectal cancer is one of the most common cancers in the world. It is well known that the chronic inflammation can promote the progression of colorectal cancer (CRC). Recently, a number of studies revealed a potential association between colorectal inflammation, cancer progression, and infection caused by enterotoxigenic Bacteroides fragilis (ETBF). Bacterial enterotoxin activates spermine oxidase (SMO), which produces spermidine and H2O2 as byproducts of polyamine catabolism, which, in turn, enhances inflammation and tissue injury. Using qPCR analysis, we estimated the expression of SMOX gene and ETBF colonization in CRC patients. We found no statistically significant associations between them. Then we selected genes involved in polyamine metabolism, metabolic reprogramming, and inflammation regulation and estimated their expression in CRC. We observed overexpression of SMOX, ODC1, SRM, SMS, MTAP, c-Myc, C/EBPβ (CREBP), and other genes. We found that two mediators of metabolic reprogramming, inflammation, and cell proliferation c-Myc and C/EBPβ may serve as regulators of polyamine metabolism genes (SMOX, AZIN1, MTAP, SRM, ODC1, AMD1, and AGMAT) as they are overexpressed in tumors, have binding site according to ENCODE ChIP-Seq data, and demonstrate strong coexpression with their targets. Thus, increased polyamine metabolism in CRC could be driven by c-Myc and C/EBPβ rather than ETBF infection.

Evageliou NF, Haber M, Vu A, et al.
Polyamine Antagonist Therapies Inhibit Neuroblastoma Initiation and Progression.
Clin Cancer Res. 2016; 22(17):4391-404 [PubMed] Related Publications
PURPOSE: Deregulated MYC drives oncogenesis in many tissues yet direct pharmacologic inhibition has proven difficult. MYC coordinately regulates polyamine homeostasis as these essential cations support MYC functions, and drugs that antagonize polyamine sufficiency have synthetic-lethal interactions with MYC Neuroblastoma is a lethal tumor in which the MYC homologue MYCN, and ODC1, the rate-limiting enzyme in polyamine synthesis, are frequently deregulated so we tested optimized polyamine depletion regimens for activity against neuroblastoma.
EXPERIMENTAL DESIGN: We used complementary transgenic and xenograft-bearing neuroblastoma models to assess polyamine antagonists. We investigated difluoromethylornithine (DFMO; an inhibitor of Odc, the rate-limiting enzyme in polyamine synthesis), SAM486 (an inhibitor of Amd1, the second rate-limiting enzyme), and celecoxib (an inducer of Sat1 and polyamine catabolism) in both the preemptive setting and in the treatment of established tumors. In vitro assays were performed to identify mechanisms of activity.
RESULTS: An optimized polyamine antagonist regimen using DFMO and SAM486 to inhibit both rate-limiting enzymes in polyamine synthesis potently blocked neuroblastoma initiation in transgenic mice, underscoring the requirement for polyamines in MYC-driven oncogenesis. Furthermore, the combination of DFMO with celecoxib was found to be highly active, alone, and combined with numerous chemotherapy regimens, in regressing established tumors in both models, including tumors harboring highest risk genetic lesions such as MYCN amplification, ALK mutation, and TP53 mutation with multidrug resistance.
CONCLUSIONS: Given the broad preclinical activity demonstrated by polyamine antagonist regimens across diverse in vivo models, clinical investigation of such approaches in neuroblastoma and potentially other MYC-driven tumors is warranted. Clin Cancer Res; 22(17); 4391-404. ©2016 AACR.

Srivastava S, Ghosh SK
Modulation of L-Arginine-Arginase Metabolic Pathway Enzymes: Immunocytochemistry and mRNA Expression in Peripheral Blood and Tissue Levels in Head and Neck Squamous Cell Carcinomas in North East India.
Asian Pac J Cancer Prev. 2015; 16(16):7031-8 [PubMed] Related Publications
BACKGROUND: Arginine may play important roles in tumor progression by providing ornithine for polyamine biosynthesis, required for cell growth. The aim of this work was to determine the expression of arginine metabolic pathway enzymes in head and neck squamous cell carcinoma (HNSCC) in northeast India.
MATERIALS AND METHODS: The expressions of arginase isoforms (ARG1 and ARG2), ornithine aminotransferase (OAT) and ornithine decarboxylase (ODC) were examined in fifty paired HNSCC and adjacent non-tumor tissues by immunohistochemistry. Immunocytochemistry, semiquantitative reverse transcription sq-PCR and quantitative real-time qPCR were used to assess protein and mRNA expressions in peripheral blood of fifty HNSCC patients and hundred controls.
RESULTS: ARG1 and ODC protein and mRNA were strongly expressed in peripheral blood from HNSCC patients. No ARG2 expression was observed. In vivo, expression of ARG1, ARG2 and ODC was significantly higher in tumor than in non-tumor tissues. Most tumors expressed low levels of OAT, with no difference in tissues or blood, compared to controls. The absolute extent of maximal ARG1 upregulation with qPCR showed 6.23 fold increase in HNSCC.
CONCLUSIONS: These findings strongly suggest that in HNSCCs, the ARG1 pathway is stimulated leading to the formation of polyamines as indicated by higher ODC expression, which promote tumor growth.

D'Amico D, Antonucci L, Di Magno L, et al.
Non-canonical Hedgehog/AMPK-Mediated Control of Polyamine Metabolism Supports Neuronal and Medulloblastoma Cell Growth.
Dev Cell. 2015; 35(1):21-35 [PubMed] Free Access to Full Article Related Publications
Developmental Hedgehog signaling controls proliferation of cerebellar granule cell precursors (GCPs), and its aberrant activation is a leading cause of medulloblastoma. We show here that Hedgehog promotes polyamine biosynthesis in GCPs by engaging a non-canonical axis leading to the translation of ornithine decarboxylase (ODC). This process is governed by AMPK, which phosphorylates threonine 173 of the zinc finger protein CNBP in response to Hedgehog activation. Phosphorylated CNBP increases its association with Sufu, followed by CNBP stabilization, ODC translation, and polyamine biosynthesis. Notably, CNBP, ODC, and polyamines are elevated in Hedgehog-dependent medulloblastoma, and genetic or pharmacological inhibition of this axis efficiently blocks Hedgehog-dependent proliferation of medulloblastoma cells in vitro and in vivo. Together, these data illustrate an auxiliary mechanism of metabolic control by a morphogenic pathway with relevant implications in development and cancer.

Miller-Fleming L, Olin-Sandoval V, Campbell K, Ralser M
Remaining Mysteries of Molecular Biology: The Role of Polyamines in the Cell.
J Mol Biol. 2015; 427(21):3389-406 [PubMed] Related Publications
The polyamines (PAs) spermidine, spermine, putrescine and cadaverine are an essential class of metabolites found throughout all kingdoms of life. In this comprehensive review, we discuss their metabolism, their various intracellular functions and their unusual and conserved regulatory features. These include the regulation of translation via upstream open reading frames, the over-reading of stop codons via ribosomal frameshifting, the existence of an antizyme and an antizyme inhibitor, ubiquitin-independent proteasomal degradation, a complex bi-directional membrane transport system and a unique posttranslational modification-hypusination-that is believed to occur on a single protein only (eIF-5A). Many of these features are broadly conserved indicating that PA metabolism is both concentration critical and evolutionary ancient. When PA metabolism is disrupted, a plethora of cellular processes are affected, including transcription, translation, gene expression regulation, autophagy and stress resistance. As a result, the role of PAs has been associated with cell growth, aging, memory performance, neurodegenerative diseases, metabolic disorders and cancer. Despite comprehensive studies addressing PAs, a unifying concept to interpret their molecular role is missing. The precise biochemical function of polyamines is thus one of the remaining mysteries of molecular cell biology.

Tamari K, Hayashi K, Ishii H, et al.
Identification of chemoradiation-resistant osteosarcoma stem cells using an imaging system for proteasome activity.
Int J Oncol. 2014; 45(6):2349-54 [PubMed] Related Publications
Osteosarcoma is the most common primary bone malignancy in pediatric and adolescent populations. Recurrence and metastatic potential can be due to a subpopulation of cells with stem cell-like characteristics, such as tumor-initiating cells (TICs), which maintain the capacity to regenerate entire tumors. Targeting the TICs in osteosarcoma is a promising avenue for the development of new therapies for this devastating disease. TICs are usually quiescent with a low protein turnover, decreased metabolism, and downregulation of proteasome activity. Recently, cancer cells with low proteasome activity have been identified as TICs in several types of cancer. We stably infected two osteosarcoma cell lines, MG-63 and U2-OS, with an expression vector for a fusion protein between the green fluorescent protein, ZsGreen, and the C-terminal degron of the murine ornithine decarboxylase to monitor the 26S proteasome activity in living cells. We separated the osteosarcoma cells with low proteasome activity using fluorescence-activated cell sorting (FACS) and verified whether these ZsGreen+ cells had TIC-like properties. The ZsGreen+ cells showed enhanced sphere formation capacity and underwent asymmetric divisions into ZsGreen+ and ZsGreen- cells, whereas ZsGreen- cells underwent only symmetric divisions into ZsGreen- cells. Moreover, the ZsGreen+ cells were more chemo- and radioresistant. Thus, the present study demonstrated that chemoradiation-resistant TICs can be visualized by this system and suggested the rationale for further study of osteosarcoma stem cells.

Jagannathan S, Vad N, Vallabhapurapu S, et al.
MiR-29b replacement inhibits proteasomes and disrupts aggresome+autophagosome formation to enhance the antimyeloma benefit of bortezomib.
Leukemia. 2015; 29(3):727-38 [PubMed] Free Access to Full Article Related Publications
Evading apoptosis is a cancer hallmark that remains a serious obstacle in current treatment approaches. Although proteasome inhibitors (PIs) have transformed management of multiple myeloma (MM), drug resistance emerges through induction of the aggresome+autophagy pathway as a compensatory protein clearance mechanism. Genome-wide profiling identified microRNAs (miRs) differentially expressed in bortezomib-resistant myeloma cells compared with drug-naive cells. The effect of individual miRs on proteasomal degradation of short-lived fluorescent reporter proteins was then determined in live cells. MiR-29b was significantly reduced in bortezomib-resistant cells as well as in cells resistant to second-generation PIs carfilzomib and ixazomib. Luciferase reporter assays demonstrated that miR-29b targeted PSME4 that encodes the proteasome activator PA200. Synthetically engineered miR-29b replacements impaired the growth of myeloma cells, patient tumor cells and xenotransplants. MiR-29b replacements also decreased PA200 association with proteasomes, reduced the proteasome's peptidase activity and inhibited ornithine decarboxylase turnover, a proteasome substrate degraded through ubiquitin-independent mechanisms. Immunofluorescence studies revealed that miR-29b replacements enhanced the bortezomib-induced accumulation of ubiquitinated proteins but did not reveal aggresome or autophagosome formation. Taken together, our study identifies miR-29b replacements as the first-in-class miR-based PIs that also disrupt the autophagy pathway and highlight their potential to synergistically enhance the antimyeloma effect of bortezomib.

Cho LY, Yang JJ, Ko KP, et al.
Gene polymorphisms in the ornithine decarboxylase-polyamine pathway modify gastric cancer risk by interaction with isoflavone concentrations.
Gastric Cancer. 2015; 18(3):495-503 [PubMed] Related Publications
BACKGROUND: The study aimed to examine the association between genes encoding molecules in the ornithine decarboxylase (ODC)-polyamine pathway (ODC1, AMD1, NQO1, NOS2A, and OAZ2) and gastric cancer risk and whether the gene-phytoestrogen interaction modifies gastric cancer risk.
METHODS: Among 76 gastric cancer cases and their 1:4 matched controls within the Korean Multi-center Cancer Cohort, a total of 30 SNPs in five genes involved in the ODC pathway were primarily analyzed. The second-stage genotyping in 388 matched case-control sets was conducted to reevaluate the significant SNPs interacting with phytoestrogens during the primary analysis. The summary odds ratios (ORs) [95 % confidence intervals (CIs)] for gastric cancer were estimated. Interaction effects between the SNPs and plasma concentrations of phytoestrogens (genistein, daidzein, equol, and enterolactone) were evaluated.
RESULTS: In the pooled analysis, NQO1 rs1800566 showed significant genetic effects on gastric cancer without heterogeneity [OR 0.83 (95 % CI 0.70-0.995)] and a greater decreased risk at high genistein/daidzein levels [OR 0.36 (95 % CI 0.15-0.90) and OR 0.26 (95 % CI 0.10-0.64), respectively; p interaction < 0.05]. Risk alleles of AMD1 rs1279599, AMD1 rs7768897, and OAZ2 rs7403751 had a significant gene-phytoestrogen (genistein and daidzein) interaction effect to modify the development of gastric cancer. They had an increased gastric cancer risk at low isoflavone levels, but a decreased risk at high isoflavone levels (p interaction < 0.01).
CONCLUSIONS: Our findings suggest that common variants in the genes involved in the ODC pathway may contribute to the risk of gastric cancer possibly by modulating ODC polyamine biosynthesis or by interaction between isoflavones and NQO1, OAZ2, and AMD1.

Symes AJ, Eilertsen M, Millar M, et al.
Quantitative analysis of BTF3, HINT1, NDRG1 and ODC1 protein over-expression in human prostate cancer tissue.
PLoS One. 2013; 8(12):e84295 [PubMed] Free Access to Full Article Related Publications
Prostate carcinoma is the most common cancer in men with few, quantifiable, biomarkers. Prostate cancer biomarker discovery has been hampered due to subjective analysis of protein expression in tissue sections. An unbiased, quantitative immunohistochemical approach provided here, for the diagnosis and stratification of prostate cancer could overcome this problem. Antibodies against four proteins BTF3, HINT1, NDRG1 and ODC1 were used in a prostate tissue array (> 500 individual tissue cores from 82 patients, 41 case pairs matched with one patient in each pair had biochemical recurrence). Protein expression, quantified in an unbiased manner using an automated analysis protocol in ImageJ software, was increased in malignant vs non-malignant prostate (by 2-2.5 fold, p<0.0001). Operating characteristics indicate sensitivity in the range of 0.68 to 0.74; combination of markers in a logistic regression model demonstrates further improvement in diagnostic power. Triple-labeled immunofluorescence (BTF3, HINT1 and NDRG1) in tissue array showed a significant (p<0.02) change in co-localization coefficients for BTF3 and NDRG1 co-expression in biochemical relapse vs non-relapse cancer epithelium. BTF3, HINT1, NDRG1 and ODC1 could be developed as epithelial specific biomarkers for tissue based diagnosis and stratification of prostate cancer.

Jacobson BA, Thumma SC, Jay-Dixon J, et al.
Targeting eukaryotic translation in mesothelioma cells with an eIF4E-specific antisense oligonucleotide.
PLoS One. 2013; 8(11):e81669 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Aberrant cap-dependent translation is implicated in tumorigenesis in multiple tumor types including mesothelioma. In this study, disabling the eIF4F complex by targeting eIF4E with eIF4E-specific antisense oligonucleotide (4EASO) is assessed as a therapy for mesothelioma.
METHODS: Mesothelioma cells were transfected with 4EASO, designed to target eIF4E mRNA, or mismatch-ASO control. Cell survival was measured in mesothelioma treated with 4EASO alone or combined with either gemcitabine or pemetrexed. Levels of eIF4E, ODC, Bcl-2 and β-actin were assessed following treatment. Binding to a synthetic cap-analogue was used to study the strength of eIF4F complex activation following treatment.
RESULTS: eIF4E level and the formation of eIF4F cap-complex decreased in response to 4EASO, but not mismatch control ASO, resulting in cleavage of PARP indicating apoptosis. 4EASO treatment resulted in dose dependent decrease in eIF4E levels, which corresponded to cytotoxicity of mesothelioma cells. 4EASO resulted in decreased levels of eIF4E in non-malignant LP9 cells, but this did not correspond to increased cytotoxicity. Proteins thought to be regulated by cap-dependent translation, Bcl-2 and ODC, were decreased upon treatment with 4EASO. Combination therapy of 4EASO with pemetrexed or gemcitabine further reduced cell number.
CONCLUSION: 4EASO is a novel drug that causes apoptosis and selectively reduces eIF4E levels, eIF4F complex formation, and proliferation of mesothelioma cells. eIF4E knockdown results in decreased expression of anti-apoptotic and pro-growth proteins and enhances chemosensitivity.

Weerawatanakorn M, Yang JR, Tsai ML, et al.
Inhibitory effects of Momordica grosvenori Swingle extracts on 12-O-tetradecanoylphorbol 13-acetate-induced skin inflammation and tumor promotion in mouse skin.
Food Funct. 2014; 5(2):257-64 [PubMed] Related Publications
Our previous data showed that the Momordica grosvenori Swingle extract (MSE) exhibited the anti-inflammatory effect through markedly suppressed LPS-induced up-regulation of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2) and ODC (ornithine decarboxylase) gene expression in RAW 264.7 cells. Regarding the link between inflammation and carcinogenesis, we further investigated the bio-molecular mechanisms of both anti-inflammatory and anti-tumor activities in vivo using a TPA (12-O-tetradecanoyl phorbol 13-acetate)-stimulated mouse skin model. Pretreatment with MSE in mouse skin has led to the reduction of TPA-induced nuclear translocation of the nuclear factor-κB (NFκB) subunits as well as phosphorylation of IκBα and p65 subsequent reduction of IκBα degradation. In addition, the MSE inhibitory effect on upstream of NFκB was found to involve the transcriptional effects of MAPK signaling as indicated by strong suppression on TPA-induced activation of extracellular signal regulate kinase (ERK)1/2, p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase (JNK)1/2, phosphatidylinositol 3-kinase (PI3K) and Akt. Moreover, MSE significantly inhibited 7,12-dimethylbenz[a]anthracene (DMBA)-TPA-induced skin tumor formation in mice measured by the tumor multiplicity of papillomas at 20 weeks. The results suggested that MSE contained promising functional ingredients capable of preventing inflammation-associated tumorigenesis.

Pietilä M, Dhungana H, Uimari A, et al.
Systemic overexpression of antizyme 1 in mouse reduces ornithine decarboxylase activity without major changes in tissue polyamine homeostasis.
Transgenic Res. 2014; 23(1):153-63 [PubMed] Related Publications
Polyamines, spermidine, spermine and their precursor putrescine, are ubiquitous cell components essential for normal cell growth. Increased polyamine levels and enhanced biosynthesis have been associated with malignant transformation and tumor formation, and thus, the polyamines have been considered to be a meaningful target to cancer therapies. However, clinical cancer treatment trials using inhibitors of polyamine synthesis have been unsuccessful probably due to compensatory uptake of polyamines from extracellular sources. The antizyme proteins regulate both polyamine biosynthesis and transport, and thus, the antizymes could provide an efficient approach to control cellular proliferation compared to the mere inhibition of biosynthesis. To define the role of antizymes in proliferative processes associated with the whole animal, we have generated transgenic mice overexpressing mouse antizyme 1 gene under its own regulatory sequences. Antizyme 1 protein was abundantly expressed in various organs and the expressed antizyme protein was functional as ornithine decarboxylase activity was significantly reduced in all tissues analyzed. However, antizyme 1 overexpression caused only minor changes in tissue polyamine levels demonstrating the challenges in using the "antizyme approach" to deplete polyamines in a living animal. Neither were there any changes in cellular proliferation in the proliferative tissues of transgenic animals. Interestingly though, there was occurrence of abnormally high level of apoptosis in the non-proliferating part of the colon epithelia. Otherwise, the transgenic founder mice appeared healthy and out of seven founders six were fertile. However, none of the founders could transmit the transgene suggesting that the antizyme 1 overexpression may be deleterious to transgenic gametes.

Wang W, Xu CX, Hou GS, et al.
Downregulation of tumstatin expression by overexpression of ornithine decarboxylase.
Oncol Rep. 2013; 30(5):2042-8 [PubMed] Free Access to Full Article Related Publications
Tumor angiogenesis, a pivotal process for cancer growth and metastasis, requires both upregulation of pro‑angiogenic molecules and downregulation of anti‑angiogenic molecules. Anti-angiogenesis therapy represents a promising way for cancer treatment. Tumstatin, a novel endogenous angiogenesis inhibitor, inhibits endothelial cell proliferation, pathological angiogenesis and tumor growth. Ornithine decarboxylase (ODC), overexpressed in various cancers, is associated with cell transformation, tumor invasion and angiogenesis. We found that the expression of tumstatin was suppressed in ODC-overexpressing human cancer cells and renal carcinoma tissues. We presumed that ODC overexpression may downregulate the expression of tumstatin. To be able to test this hypothesis, we generated HEK293 cells that overexpress ODC (ODC transfectants) and characterized the following experimental groups: PBS-treated group, mock transfectants, ODC transfectants, ODC transfectants transfected with pcDNA-ODCr (an antisense ODC-expressing plasmid) group and putrescine-treated group. The effect of ODC overexpression on tumstatin expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR), western blot analysis and dual luciferase reporter assay. ODC-overexpressing cells and putrescine-treated cells showed suppressed tumstatin mRNA and protein expression, and decreased tumstatin gene promoter activity. Thus, ODC overexpression suppresses the expression of tumstatin, which may provide fundamental evidence for the combination of anti-angiogenic therapy and conventional therapy for cancer treatment.

Tomasi ML, Ryoo M, Skay A, et al.
Polyamine and methionine adenosyltransferase 2A crosstalk in human colon and liver cancer.
Exp Cell Res. 2013; 319(12):1902-11 [PubMed] Free Access to Full Article Related Publications
Methionine adenosyltransferase (MAT) is an essential enzyme that is responsible for the biosynthesis of S-adenosylmethionine (SAMe), the principal methyl donor and precursor of polyamines. MAT1A is expressed in normal liver and MAT2A is expressed in all extrahepatic tissues. MAT2A expression is increased in human colon cancer and in colon cancer cells treated with mitogens, whereas silencing MAT2A resulted in apoptosis. The aim of the current work was to examine the mechanism responsible for MAT2A-dependent growth and apoptosis. We found that in RKO (human adenocarcinoma cell line) cells, MAT2A siRNA treatment lowered cellular SAMe and putrescine levels by 70-75%, increased apoptosis and inhibited growth. Putrescine supplementation blunted significantly MAT2A siRNA-induced apoptosis and growth suppression. Putrescine treatment (100pmol/L) raised MAT2A mRNA level to 4.3-fold of control, increased the expression of c-Jun and c-Fos and binding to an AP-1 site in the human MAT2A promoter and the promoter activity. In human colon cancer specimens, the expression levels of MAT2A, ornithine decarboxylase (ODC), c-Jun and c-Fos are all elevated as compared to adjacent non-tumorous tissues. Overexpression of ODC in RKO cells also raised MAT2A mRNA level and MAT2A promoter activity. ODC and MAT2A are also overexpressed in liver cancer and consistently, similar MAT2A-ODC-putrescine interactions and effects on growth and apoptosis were observed in HepG2 cells. In conclusion, there is a crosstalk between polyamines and MAT2A. Increased MAT2A expression provides more SAMe for polyamines biosynthesis; increased polyamine (putrescine in this case) can activate MAT2A at the transcriptional level. This along with increased ODC expression in cancer all feed forward to further enhance the proliferative capacity of the cancer cell.

Koomoa DL, Geerts D, Lange I, et al.
DFMO/eflornithine inhibits migration and invasion downstream of MYCN and involves p27Kip1 activity in neuroblastoma.
Int J Oncol. 2013; 42(4):1219-28 [PubMed] Free Access to Full Article Related Publications
Neuroblastoma (NB) is the most common extracranial pediatric tumor. NB patients over 18 months of age at the time of diagnosis are often in the later stages of the disease, present with widespread dissemination, and often possess MYCN tumor gene amplification. MYCN is a transcription factor that regulates the expression of a number of genes including ornithine decarboxylase (ODC), a rate-limiting enzyme in the biosynthesis of polyamines. Inhibiting ODC in NB cells produces many deleterious effects including G(1) cell cycle arrest, inhibition of cell proliferation, and decreased tumor growth, making ODC a promising target for drug interference. DFMO treatment leads to the accumulation of the cyclin-dependent kinase inhibitor p27(Kip1) protein and causes p27(Kip1)/Rb-coupled G(1) cell cycle arrest in MYCN-amplified NB tumor cells through a process that involves p27(Kip1) phosphorylation at residues Ser10 and Thr198. While p27(Kip1) is well known for its role as a cyclin-dependent kinase inhibitor, recent studies have revealed a novel function of p27(Kip1) as a regulator of cell migration and invasion. In the present study we found that p27(Kip1) regulates the migration and invasion in NB and that these events are dependent on the state of phosphorylation of p27(Kip1). DFMO treatments induced MYCN protein downregulation and phosphorylation of Akt/PKB (Ser473) and GSK3-β (Ser9), and polyamine supplementation alleviated the DFMO-induced effects. Importantly, we provide strong evidence that p27(Kip1) mRNA correlates with clinical features and the survival probability of NB patients.

Raj KP, Zell JA, Rock CL, et al.
Role of dietary polyamines in a phase III clinical trial of difluoromethylornithine (DFMO) and sulindac for prevention of sporadic colorectal adenomas.
Br J Cancer. 2013; 108(3):512-8 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: The polyamine-inhibitory regimen difluoromethylornithine (DFMO)+sulindac has marked efficacy in preventing metachronous colorectal adenomas. Polyamines are synthesised endogenously and obtained from dietary sources. Here we investigate dietary polyamine intake and outcomes in the DFMO+sulindac colorectal adenoma prevention trial.
METHODS: Dietary polyamine data were available for 188 of 267 patients completing the study. Total dietary polyamine content was derived by the sum of dietary putrescine, spermine and spermidine values and categorised into two groups: highest (>75-100%) vs the lower three quartiles (0-25, 25-50 and 50-75%). Baseline tissue polyamine concentration and ODC1 genotype were determined. Logistic regression models were used for risk estimation.
RESULTS: A significant interaction was detected between dietary polyamine group and treatment with regard to adenoma recurrence (P=0.012). Significant metachronous adenoma risk reduction was observed after DFMO+sulindac treatment in dietary polyamine quartiles 1-3 (risk ratio (RR) 0.19; 95% confidence interval (CI) 0.08-0.42; P<0.0001) but not in quartile 4 (RR 1.51; 95% CI 0.53-4.29; P=0.44). However, a lower number of events in the placebo group within dietary quartile 4 confound the aforementioned risk estimates.
CONCLUSION: These preliminary findings reveal complex relationships between diet and therapeutic prevention, and they support further clinical trial-based investigations where the dietary intervention itself is controlled.

Funakoshi-Tago M, Sumi K, Kasahara T, Tago K
Critical roles of Myc-ODC axis in the cellular transformation induced by myeloproliferative neoplasm-associated JAK2 V617F mutant.
PLoS One. 2013; 8(1):e52844 [PubMed] Free Access to Full Article Related Publications
The acquired mutation (V617F) of Janus kinase 2 (JAK2) is observed in the majority of patients with myeloproliferative neoplasms (MPNs). In the screening of genes whose expression was induced by JAK2 (V617F), we found the significant induction of c-Myc mRNA expression mediated by STAT5 activation. Interestingly, GSK-3β was inactivated in transformed Ba/F3 cells by JAK2 (V617F), and this enhanced the protein expression of c-Myc. The enforced expression of c-Myc accelerated cell proliferation but failed to inhibit apoptotic cell death caused by growth factor deprivation; however, the inhibition of GSK-3β completely inhibited the apoptosis of cells expressing c-Myc. Strikingly, c-Myc T58A mutant exhibited higher proliferative activity in a growth-factor-independent manner; however, this mutant failed to induce apoptosis. In addition, knockdown of c-Myc significantly inhibited the proliferation of transformed cells by JAK2 (V617F), suggesting that c-Myc plays an important role in oncogenic activity of JAK2 (V617F). Furthermore, JAK2 (V617F) induced the expression of a target gene of c-Myc, ornithine decarboxylase (ODC), known as the rate-limiting enzyme in polyamine biosynthesis. An ODC inhibitor, difluoromethylornithine (DFMO), prevented the proliferation of transformed cells by JAK2 (V617F). Importantly, administration of DFMO effectively delayed tumor formation in nude mice inoculated with transformed cells by JAK2 (V617F), resulting in prolonged survival; therefore, ODC expression through c-Myc is a critical step for JAK2 (V617F)-induced transformation and DFMO could be used as effective therapy for MPNs.

Gupta NK, Gupta KP
Effects of C-Phycocyanin on the representative genes of tumor development in mouse skin exposed to 12-O-tetradecanoyl-phorbol-13-acetate.
Environ Toxicol Pharmacol. 2012; 34(3):941-8 [PubMed] Related Publications
C-Phycocyanin (C-PC), a biliprotein from the sea weed, has been shown to have the beneficial effects like antioxidant, anti-inflammatory, neuroprotective, and hepatoprotective properties and is used as food supplement. We are showing the effect of C-Phycocyanin on the early events altered by tumor promoter. TPA induced the expression of critical events of tumorigenesis like ornithine decarboxylase, cyclooxygenase-2, interleukin-6 and pSTAT3 in mouse skin after 5h of application, whereas expression of transglutaminase2 was decreased at this time point. This TPA-caused altered expression of genes was prevented in presence of C-Phycocyanin. This prevention by C-Phycocyanin appeared to be dependent on the dose of C-Phycocyanin used. The results are useful for the detailed study on the preventive effect of C-Phycocyanin on TPA induced tumor promotion.

Morozov AV, Morozov VA, Astakhova TM, et al.
[DNA vaccine encoding alpha-fetoprotein with fused ornithine decarboxylase degradation signal significantly suppresses hepatocellular carcinoma growth in mice].
Mol Biol (Mosk). 2012 May-Jun; 46(3):434-51 [PubMed] Related Publications
Hepatocellular carcinoma (HCC) is among the most frequent malignancies in humans. HCC therapy is not efficient and the usual outcome is poor. In this regard, novel approaches to treat and prevent HCC are urgently needed. The Alpha-fetoprotein (AFP) is a serological marker of HCC. Recently it has been shown, that the DNA vaccines expressing AFP are capable in generating immune response against AFP. However, both, the immunization procedures and DNA vaccines used before were complex and not always very effective. We have shown that DNA vaccine encoding HIV-1 reverse transcriptase (RT) with fused ornithine decarboxylase (ODC) degradation signal induced a strong Th-1 immune response against RT in mice. Using this approach we designed a set of novel DNA vaccines bearing AFP and ODC degradation signal. Results obtained on transfected cells demonstrated efficient expression and fast proteasomal degradation of the recombinant AFP. The anti-tumor immune response stimulation was shown in immunized animals and most importantly a notable retardation of tumor growth was observed as a result of protective vaccination.

Vargas AJ, Wertheim BC, Gerner EW, et al.
Dietary polyamine intake and risk of colorectal adenomatous polyps.
Am J Clin Nutr. 2012; 96(1):133-41 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Putrescine, spermidine, and spermine are the polyamines required for human cell growth. The inhibition of ornithine decarboxylase (ODC), which is the rate-limiting enzyme of polyamine biosynthesis, decreases tumor growth and the development of colorectal adenomas. A database was developed to estimate dietary polyamine exposure and relate exposure to health outcomes.
OBJECTIVE: We hypothesized that high polyamine intake would increase risk of colorectal adenoma and that the allelic variation at ODC G>A +316 would modify the association.
DESIGN: Polyamine exposure was estimated in subjects pooled (n = 1164) from the control arms of 2 randomized trials for colorectal adenoma prevention [Wheat Bran Fiber low-fiber diet arm (n = 585) and Ursodeoxycholic Acid placebo arm (n = 579)] by using baseline food-frequency questionnaire data. All subjects had to have a diagnosis of colorectal adenoma to be eligible for the trial.
RESULTS: A dietary intake of polyamines above the median amount in the study population was associated with 39% increased risk of colorectal adenoma at follow-up (adjusted OR: 1.39; 95% CI: 1.06, 1.83) in the pooled sample. In addition, younger participants (OR: 1.94; 95% CI: 1.23, 3.08), women (OR: 2.43; 95% CI: 1.48, 4.00), and ODC GG genotype carriers (OR: 1.59; 95% CI: 1.00, 2.53) had significantly increased odds of colorectal adenoma if they consumed above-median polyamine amounts.
CONCLUSIONS: This study showed a role for dietary polyamines in colorectal adenoma risk. Corroboration of these findings would confirm a previously unrecognized, modifiable dietary risk factor for colorectal adenoma.

Smirnova OA, Isaguliants MG, Hyvonen MT, et al.
Chemically induced oxidative stress increases polyamine levels by activating the transcription of ornithine decarboxylase and spermidine/spermine-N1-acetyltransferase in human hepatoma HUH7 cells.
Biochimie. 2012; 94(9):1876-83 [PubMed] Related Publications
Biogenic polyamines spermine and spermidine participate in numerous cellular processes including transcription, RNA processing and translation. Specifically, they counteract oxidative stress, an alteration of cell redox balance involved in generation and progression of various pathological states including cancer. Here, we investigated how chemically induced oxidative stress affects polyamine metabolism, specifically the expression and activities of enzymes catalyzing polyamine synthesis (ornithine decarboxylase; ODC) and degradation (spermidine/spermine-N(1)-acetyltransferase; SSAT), in human hepatoma cells. Oxidative stress induced the up-regulation of ODC and SSAT gene transcription mediated by Nrf2, and in case of SSAT, also by NF-κB transcription factors. Activation of transcription led to the elevated intracellular activities of both enzymes. The balance in antagonistic activities of ODC and SSAT in the stressed hepatoma cells was shifted towards polyamine biosynthesis, which resulted in increased intracellular levels of putrescine, spermidine, and spermine. Accumulation of putrescine is indicating for accelerated degradation of polyamines by SSAT - acetylpolyamine oxidase (APAO) pathway generating toxic products that promote carcinogenesis, whereas accelerated polyamine synthesis via activation of ODC is favorable for proliferation of cells including those sub-lethally damaged by oxidative stress.

Kumar KN, Raja SB, Vidhya N, Devaraj SN
Ellagic acid modulates antioxidant status, ornithine decarboxylase expression, and aberrant crypt foci progression in 1,2-dimethylhydrazine-instigated colon preneoplastic lesions in rats.
J Agric Food Chem. 2012; 60(14):3665-72 [PubMed] Related Publications
Chemoprevention offers a novel approach to control the incidence of colorectal cancer (CRC), which is a fatal cause of malignancies in both Western and Asia countries. Ornithine decarboxylase (ODC) functions as a cell transition factor by regulating the biosynthesis of polyamines, which, allied with aberrant crypt foci (ACF) proliferation, cause early lesions of CRC. This study exemplifies the chemopreventive efficacy of ellagic acid (EA) in 1,2-dimethylhydrazine (DMH) initiated CRC in rats. Subcutaneous injection of DMH (40 mg/kg body weight twice a week for 2 weeks) to the rats resulted in elevated expression of ODC, a genetic marker for CRC, and its transcription factor myelocytomatosis oncogene (c-myc). Furthermore, increased levels of lipid peroxidation and hydroperoxides with diminished levels of antioxidants including superoxide dismutase, catalase, and reduced glutathione were also observed in the tissues of DMH-intoxicated rats. Oral supplementation of EA significantly influences maintenance of antioxidant status and transcriptional inactivation of ODC expression, reducing ACF proliferation and/or progression, thus signifying the chemopreventive efficacy of EA against CRC.

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