Ornithine decarboxylase, mitogen-activated protein kinase and matrix metalloproteinase-2 expressions in human colon tumors

AIM: To investigate the expressions of omithine decarboxylase (ODC), MMP-2, and Erk, and their relationship in human colon tumors.METHODS: ODC activity, MMP-2 expression, and mitogenactivated protein (MAP) kinase activity (Erk phosphorylation) were determined in 58 surgically removed human colon tumors and their adjacent normal tissues, using [1-14C]-ornithine as a substrate, ELISA assay, and Western blotting, respectively.RESULTS: ODC activity, MMP-2 expression, and Erk phosphorylation were significantly elevated in colon tumors, compared to those in adjacent normal tissues. A significant correlation was observed between ODC activities and MMP-2 levels.CONCLUSION: This is the first report showing a significant correlation between ODC activities and MMP-2 levels in human colon tumors. As MMP-2 is involved in cancer invasion and metastasis, and colon cancer overexpresses ODC, suppression of ODC expression may be a rational approach to treat colon cancer which overexpresses ODC.

Expression of ornithine decarboxylase in precancerous and cancerous gastric lesions

AIM: To investigate the expression of ornithine decarboxylase (ODC) in precancerous and cancerous gastric lesions. METHODS: We studied the expression of ODC in gastric mucosa from patients with chronic superficial gastritis (CSG,n = 32),chronic atrophic gastritis CAG,n = 43; 15 with and 28 without intestinal metaplasia (IM),gastric dysplasia (DYS,n = 11) and gastric cancer (GC,n = 48) tissues using immunohistochemical staining. All 134 biopsy specimens of gastric mucosa were collected by gastroscopy. METHODS: The positive rate of ODC expression was 34.4%,42.9%,73.3%,81.8% and 91.7% in cases with CSG,CAG without IM,CAG with IM,DYS and GC,respectively (P < 0.01),The positive rate of ODC expression increased in the order of CSG < CAG (without IM) < CAG (with IM) < DYS and finally,GC. In addition,ODC positive immunostaining rate was lower in well-differentiated GC than in poorly-differentiated GC (P < 0.05). CONCLUSION: The expression of ODC is positively correlated with the degree of malignity of gastric mucosa and development of gastric lesions. This finding indicates that ODC may be used as a good biomarker in the screening and diagnosis of precancerous lesions.

Ornithine decarboxylase gene is overexpressed in colorectal carcinoma

AIM: To investigate the ornithine decarboxylase (ODC)gene expression in colorectal carcinoma, ODC mRNA was assayed by RT-PCR and ODC protein was detected by a monoclonal antibody against fusion of human colon ODC prepared by hybridoma technology.METHODS: Total RNA was extracted from human colorectal cancer tissues and their normal counterpart tissues. ODC mRNA levels were examined by RT-PCR.ODC genes amplified from RT-PCR were cloned into a prokaryotic vector pQE-30. The expressed proteins were purified by chromatography. Anti-ODC mAb was prepared with classical hybridoma techniques and used to determine the ODC expression in colon cancer tissues by immunohistochemical and Western blotting assay.RESULTS: A cell line, which could steadily secrete antiODC mAb, was selected through subcloning four times.Western blotting reconfirmed the mAb and ELISA showed that its subtype was IgG2a. RT-PCR showed that the ODC mRNA level increased greatly in colon cancer tissues (P＜0.01). Immunohistochemical staining showed that colorectal carcinoma cells expressed a significantly higher level of ODC than normal colorectal mucosa (98.6±1.03%vs 5.26±5%, P＜0.01).CONCLUSION: ODC gene overexpression is significantly related to human colorectal carcinoma. ODC gene expression may be a marker for the gene diagnosis and therapy of colorectal carcinoma.

THE EFFECTS OF CHINESE DRUGS FOR SUPPORTING HEALTHY ENERGY AND REMOVING BLOOD STASIS ON POSTOPERATIVE METASTASIS OF GASTRIC CARCINOMA AND ORNITHINE DECARBOXYLASE

32 postoperative cases of gastric carcinoma were treated by traditional Chinese medicine (TCM) drugs for supporting healthy energy and removing blood stasis, and their therapeutic results were compared with those in the control group treated by western medicine. After 6 months of treatment, in the TCM group, the rate of metastatic recurrence was significantly reduced, and the level of ornithine decarboxylase was also markedly lowered. Therefore, it is considered that the action of anti-metastatic recurrence of TCM drugs in postoperative cases of gastric carcinoma is probably related to the lowered activity of ornithine decarboxylase.

REVERSION OF MALIGNANT PHENOTYPES OF HUMAN LUNG SQUAMOUS CARCINOMA CELLS BY ORNITHINE DECARBOXYLASE ANTISENSE RNA

Abnormally elevated activity of ornithine decarboxylase (ODC), and subsequent polyamine accumulation are intimately associated with the genesis.development and metastasis of cancer. In the present study, to control the growth of tumor cells, ODC antisense RNA was used to transfect human lung squamous carcinoma cell line LTEP-78. Compared with the parental cells, growth of the antisense transfected LTEP-78 cells arrested in G0/Gl phase and colony formation in soft agarose and tumorigenicity in nude mice were significantly reduced. Nucleic acid hybridization demonstrated that the transfectants expressed a high level of ODC antisense RNA and a significantly reduced level of endogenous ODC mRNA.The results suggest that the reversion of malignant phenotypes of human lung squamous carcinoma cells transfected with ODC antisense RNA is associated with the inhibition of polyamine biosynthesis.

Effect of diethylstilbestrol on polyamine metabolism in hamster epididymis

<abstract>Aim: To investigate the effect of diethylstilbestrol (DES), one of the most potent endocrine disruptors, on the metabolism of polyamines in hamster epididymis. Methods: Male golden hamsters of 7-week-old were kept under a light and dark cycle of 14 h and 10 h for 1 week to stimulate maximally the gonadal function. DES was injected subcutaneously at doses of 0.01 mg·kg-1·day-1, 0.1 mg·kg-1·day-1 and 1 mg·kg-1·day-1 for one week. Results: DES treatment caused a significant decrease in the weight of epididymis. The activity of epididymal ornithine decar boxylase (ODC) increased 1 day after DES treatment, kept at a high level for 4 days and then decreased to nearly normal level at day 7. The activity of spermidine/spermine N1-acetyltransferase (SSAT) also increased transiently after DES treatment. The contents of putrescine, spermidine, spermine and N1-acetylspermidine were increased 1 day -4 days after DES treatment and restored to normal at day 7. All these changes showed a marked difference between the caput and the cauda. Conclusion: The polyamine biosynthesis in the hamster epididymis can be affected by DES, a xenoestrogen. DES may probably affect polyamine metabolism in the epididymis by regulating the rate-limiting enzymes involved in the polyamine biosynthesis.

Effects of Nicotinamide on Mouse Skin Tumor Development and Its Mode of Action

Nicotinamide (NA), a naturally occuring vitamin and a protease inhibitor, has been shown to be effective in treating some skin ailments. It inhibits cell proiferaion and induces cell differentiation. This report shows the effects of NA on mouse skin tumor development and on the critical events involved in this process. NA reduced tumor growth, inhibited the 12-O-tetradecanoylphorbol-13-acetate (TPA) induced ornithine decarboxylase activity, but induced the transglutaminare activity which was inhibited by TPA under different experimental conditions.The effects of NA on ornithine decarboxylare (ODC) and transglutaminase (TG) indicated that nicotinamide (NA) probably programmmed the cells for their death in the natural course of time, i.e. programed cell death. This observation indicates that NA might be a better agent for the detailed study and for the better use in prevention of cancer alone or in combination with other drugs.

Prostate Specific Antigen Promoter-Driven Adenovirus-Mediated Expression of Both ODC and AdoMetDC Antisenses Inhibit Prostate Cancer Growth

Objective：To generate recombinant adenovirus that could simultaneously express ornithine decarboxylase（ODC） and S-adenosylmethionine decarboxylase（AdoMetDC） antisenses specifically in prostate cancer cells,and evaluate its inhibitory effect on prostate cancer in vivo.Methods：Fragments of ODC and AdoMetDC genes were generated by PCR,cloned into the pPGL-PSES,and then recombined with pAdEasy-1 vectors in AdEasy-1 cells.Ad-PSES-ODC-AdoMetDCas virus was produced in HEK293 cells.Following transfection with Ad-PSES-ODC-AdoMetDCas,the levels of ODC or AdoMetDC were determined by RT-PCR and western blot assays.The effect of Ad-PSES-ODC-AdoMetDCas treatment on tumor formation and growth was evaluated in xenograft models of prostate cancers in vivo.Results：The plasmid pAdEasy-PSES-ODC-AdoMetDCas was successfully constructed and the recombinant Ad-PSES-ODC-AdoMetDCas adenovirus was produced.Transfection with Ad-PSES-ODC-AdoMetDCas adenovirus significantly inhibited the expression of ODC and AdoMetDC genes specifically in prostate DU145 cells,but not H1299,HT29 and HepG2 cancer cells,and disrupted the ability of DU145 cells to form solid prostate cancer in vivo.Intratumoral treatment with Ad-PSES-ODC-AdoMetDCas adenovirus significantly inhibited the growth of engrafted prostate tumors in vivo.Conclusion：The recombinant Ad-PSES-ODC-AdoMetDCas adenovirus specifically reduces the expression of both ODC and AdoMetDC genes in prostate cells and may be used for treatment of prostate cancers at the clinic.

Molecular evidence suggests that the enigmatic Sulawesi endemic Geomalia heinrichi belongs in the genus Zoothera (Turdidae, Aves)

The taxonomic status of the Sulawesi endemic Geomalia heinrichi has long been debated, and it has variously been treated as a babbler (Timaliidae) or a turdid (Turdidae). We estimated the phylogeny of 43 taxa in the family Turdidae based on the mitochondrial cytochrome b gene and the nuclear myoglobin intron 2 and ornithine decarboxylase introns 6–7. Geomalia heinrichi was shown to be part of the Zoothera clade with high support. We propose that Geomalia is transferred to Zoothera under the name Zoothera heinrichi.

Comparison of the signaling pathways of wing dimorphism regulated by biotic and abiotic stress in the brown planthopper

Wing polymorphism is an evolutionary trait that is widely present in various insects and provides a model system for studying the evolutionary significance of insect dispersal.The brown planthopper(BPH,Nilaparvata lugens)can alter its wing morphs un-der biotic and abiotic stress.However,whether differential signaling pathways are induced by the 2 types of stress remain largely unknown.Here,we screened a number of candidate genes through weighted gene co-expression network analysis(WGCNA)and found that ornithine decarboxylase(NIODC),a key enzyme in the synthesis of polyamines,was as-sociated with wing differentiation in BPH and mainly responded to abiotic stress stimuli.We analyzed the Kyoto Encyclopedia of Genes and Genomes enrichment pathways of dif-ferentially expressed genes under the 2 stresses by transcriptomic comparison,and found that biotic stress mainly influenced insulin-related signaling pathways while abiotic stress mainly influenced hormone-related pathways.Moreover,we found that insulin receptor 1(NllnRI)may regulate wing differentiation of BPH by responding to both biotic and abiotic stress,but NllnR2 only responded to biotic stress.Similarly,the juvenile hormone epoxide hydrolase associated with juvenile hormone degradation and NIODC may regu-late wing differentiation mainly through abiotic stress.A model based on the genes and stresses to modulate the wing dimorphism of BPH was proposed.These findings present a comprehensive molecular mechanism for wing polymorphism in BPH induced by biotic and abiotic stress.

Regulatory role of L-proline in fetal pig growth and intestinal epithelial cell proliferation

L-proline(Pro)is a precursor of ornithine,which is converted into polyamines via ornithine decarboxylase(ODC).Polyamines plays a key role in the proliferation of intestinal epithelial cells.The study investigated the effect of Pro on polyamine metabolism and cell proliferation on porcine enterocytes in vivo and in vitro.Twenty-four Huanjiang mini-pigs were randomly assigned into 1 of 3 groups and fed a basal diet that contained 0.77%alanine(Ala,iso-nitrogenous control),1%Pro or 1%Pro+0.0167%α-difluoromethylornithine(DFMO)from d 15 to 70 of gestation.The fetal body weight and number of fetuses per litter were determined,and the small and large intestines were obtained on d 70±1.78 of gestation.The in vitro study was performed in intestinal porcine epithelial(IPEC-J2)cells cultured in Dulbecco’s modified Eagle medium-high glucose(DMEM-H)containing 0μmol/L Pro,400μmol/L Pro,or400μmol/L Pro+10 mmol/L DFMO for 4 d.The results showed that maternal dietary supplementation with 1%Pro increased fetal weight;the protein and DNA concentrations of the fetal small intestine;and mRNA levels for potassium voltage-gated channel,shaker-related subfamily,member 1(Kv1.1)in the fetal small and large intestines(P<0.05).Supplementing Pro to either gilts or IPEC-J2 cells increased ODC protein abundances and polyamine concentrations in the fetal intestines and IPEC-J2 cells(P<0.05).In comparison with the Pro group,the combined administration of Pro and DFMO reduced the expression of ODC protein and spermine concentration in the fetal intestine,as well as the concentrations of putrescine,spermidine and spermine in IPEC-J2 cells(P<0.05).Meanwhile,the percentage of cells in the S-phase and the mRNA levels of proto-oncogenes c-fos and c-myc were increased in response to Pro supplementation,whereas depletion of cellular polyamines with DFMO increased tumor protein p53(p53)mRNA levels(P<0.05).Taken together,dietary supplementation with Pro improved fetal pig growth and intestinal epithelial cell proliferation via enhancing polyamine synthesis.