Peroxisome proliferator-activated receptor gamma and spermidine/spermine N(1)-acetyltransferase gene expressions are significantly correlated in human colorectal cancer

BACKGROUND: The peroxisome proliferator-activated receptor γ (PPARγ) is a transcription factor that regulates adipogenic differentiation and glucose homeostasis. Spermidine/spermine N(1)-acetyltransferase (SSAT) and ornithine decarboxylase (ODC) are key enzymes involved in the metabolism of polyamines, compounds that play an important role in cell proliferation. While the PPARγ role in tumour growth has not been clearly defined, the involvement of the altered polyamine metabolism in colorectal carcinogenesis has been established. In this direction, we have evaluated the PPARγ expression and its relationship with polyamine metabolism in tissue samples from 40 patients operated because of colorectal carcinoma. Since it is known that the functional role of K-ras mutation in colorectal tumorigenesis is associated with cell growth and differentiation, polyamine metabolism and the PPARγ expression were also investigated in terms of K-ras mutation. METHODS: PPARγ, ODC and SSAT mRNA levels were evaluated by reverse transcriptase and real-time PCR. Polyamines were quantified by high performance liquid chromatography (HPLC). ODC and SSAT activity were measured by a radiometric technique. RESULTS: PPARγ expression, as well as SSAT and ODC mRNA levels were significantly higher in cancer as compared to normal mucosa. Tumour samples also showed significantly higher polyamine levels and ODC and SSAT activities in comparison to normal samples. A significant and positive correlation between PPARγ and the SSAT gene expression was observed in both normal and neoplastic tissue (r = 0.73, p < 0.0001; r = 0.65, p < 0.0001, respectively). Moreover, gene expression, polyamine levels and enzymatic activities were increased in colorectal carcinoma samples expressing K-ras mutation as compared to non mutated K-ras samples. CONCLUSION: In conclusion, our data demonstrated a close relationship between PPARγ and SSAT in human colorectal cancer and this could represent an attempt to decrease polyamine levels and to reduce cell growth and tumour development. Therefore, pharmacological activation of PPARγ and/or induction of SSAT may represent a therapeutic or preventive strategy for treating colorectal cancer

Effects of probiotic bacteria (VSL#3) on the polyamine biosynthesis and cell proliferation of normal colonic mucosa of rats

Abstract. Background: Probiotics seem to possess tumour inhibitory properties, but few studies have investigated their actions on the cell proliferation of normal colonic mucosa. The effects of a probiotic mixture (VSL#3) on polyamine biosynthesis, Ki-67 levels and apoptosis in the normal colon of rats were studied. Materials and Methods: For a 4-week period, 20 rats were fed a VSL#3 solution and 20 rats a saline solution. Samples from the colonic mucosa were collected at the end of treatment. Polyamines were detected by HPLC, ornithine decarboxylase activity by a radiometric technique, and apoptosis and Ki-67 by histochemical and immunohistochemical methods. Results: VSL#3 caused a significant decrease in colonic polyamine levels, ornithine decarboxylase activity and Ki-67 compared to controls. A significant increase in the apoptotic index was also observed. Conclusion: Probiotics could also reduce proliferation rates in a condition not affected by hyperproliferative or neoplastic growth, when the normal control mechanisms are still completely effective

Pro-oxidant effects of Verbascoside, a bioactive compound from olive oil mill wastewater, on in vitro developmental potential of ovine prepubertal oocytes and bioenergetic/oxidative stress parameters of fresh and vitrified oocytes

Verbascoside (VB) is a bioactive polyphenol from olive oil mill wastewater with known antioxidant activity. Oxidative stress is an emerging problem in assisted reproductive technology (ART). Juvenile ART is a promising topic because, in farm animals, it reduces the generation gap and, in human reproductive medicine, it helps to overcome premature ovarian failure. The aim of this study was to test the effects of VB on the developmental competence of ovine prepubertal oocytes and the bioenergetic/oxidative stress status of fresh and vitrified oocytes. In fresh oocytes, VB exerted prooxidant short-term effects, that is, catalase activity increase and uncoupled increases of mitochondria and reactive oxygen species (ROS) fluorescence signals, and long-term effects, that is, reduced blastocyst formation rate. In vitrified oocytes, VB increased ROS levels. Prooxidant VB effects in ovine prepubertal oocytes could be related to higher VB accumulation, which was found as almost one thousand times higher than that reported in other cell systems in previous studies. Also, long exposure times of oocytes to VB, throughout the duration of in vitro maturation culture, may have contributed to significant increase of oocyte oxidation. Further studies are needed to identify lower concentrations and/or shorter exposure times to figure out VB antioxidant effects in juvenile ARTs

RAN Translation at \u3cem\u3eC9orf72\u3c/em\u3e-Associated Repeat Expansions is Selectively Enhanced by the Integrated Stress Response

Repeat-associated non-AUG (RAN) translation allows for unconventional initiation at disease-causing repeat expansions. As RAN translation contributes to pathogenesis in multiple neurodegenerative disorders, determining its mechanistic underpinnings may inform therapeutic development. Here we analyze RAN translation at G4C2 repeat expansions that cause C9orf72-associated amyotrophic lateral sclerosis and frontotemporal dementia (C9RAN) and at CGG repeats that cause fragile X-associated tremor/ataxia syndrome. We find that C9RAN translation initiates through a cap- and eIF4A-dependent mechanism that utilizes a CUG start codon. C9RAN and CGG RAN are both selectively enhanced by integrated stress response (ISR) activation. ISR-enhanced RAN translation requires an eIF2α phosphorylation-dependent alteration in start codon fidelity. In parallel, both CGG and G4C2 repeats trigger phosphorylated-eIF2α-dependent stress granule formation and global translational suppression. These findings support a model whereby repeat expansions elicit cellular stress conditions that favor RAN translation of toxic proteins, creating a potential feed-forward loop that contributes to neurodegeneration

Corrigendum: FLASH Radiotherapy With Electrons: Issues Related to the Production, Monitoring, and Dosimetric Characterization of the Beam

In the original article, the following authors were missing: Luigi Faillace, Lucia Giuliano, Mauro Migliorati, Luigi Palumbo. The corrected Author Contributions statement appears below. Affiliation 3, ‘Sapienza University of Rome, Rome, Italy’, is also added for authors LF, LG, MM, and LP. The authors apologize for these errors and state that this does not change the scientific conclusions of the article in any way. The original article has been updated

Image resampling and discretization effect on the estimate of myocardial radiomic features from T1 and T2 mapping in hypertrophic cardiomyopathy

Radiomics is emerging as a promising and useful tool in cardiac magnetic resonance (CMR) imaging applications. Accordingly, the purpose of this study was to investigate, for the first time, the effect of image resampling/discretization and filtering on radiomic features estimation from quantitative CMR T1 and T2 mapping. Specifically, T1 and T2 maps of 26 patients with hypertrophic cardiomyopathy (HCM) were used to estimate 98 radiomic features for 7 different resampling voxel sizes (at fixed bin width), 9 different bin widths (at fixed resampling voxel size), and 7 different spatial filters (at fixed resampling voxel size/bin width). While we found a remarkable dependence of myocardial radiomic features from T1 and T2 mapping on image filters, many radiomic features showed a limited sensitivity to resampling voxel size/bin width, in terms of intraclass correlation coefficient (&gt; 0.75) and coefficient of variation (&lt; 30%). The estimate of most textural radiomic features showed a linear significant (p &lt; 0.05) correlation with resampling voxel size/bin width. Overall, radiomic features from T2 maps have proven to be less sensitive to image preprocessing than those from T1 maps, especially when varying bin width. Our results might corroborate the potential of radiomics from T1/T2 mapping in HCM and hopefully in other myocardial diseases

DDX3X and specific initiation factors modulate FMR1 repeat‐associated non‐AUG‐initiated translation

A CGG trinucleotide repeat expansion in the 5′ UTR of FMR1 causes the neurodegenerative disorder Fragile X‐associated tremor/ataxia syndrome (FXTAS). This repeat supports a non‐canonical mode of protein synthesis known as repeat‐associated, non‐AUG (RAN) translation. The mechanism underlying RAN translation at CGG repeats remains unclear. To identify modifiers of RAN translation and potential therapeutic targets, we performed a candidate‐based screen of eukaryotic initiation factors and RNA helicases in cell‐based assays and a Drosophila melanogaster model of FXTAS. We identified multiple modifiers of toxicity and RAN translation from an expanded CGG repeat in the context of the FMR1 5′UTR. These include the DEAD‐box RNA helicase belle/DDX3X, the helicase accessory factors EIF4B/4H, and the start codon selectivity factors EIF1 and EIF5. Disrupting belle/DDX3X selectively inhibited FMR1 RAN translation in Drosophila in vivo and cultured human cells, and mitigated repeat‐induced toxicity in Drosophila and primary rodent neurons. These findings implicate RNA secondary structure and start codon fidelity as critical elements mediating FMR1 RAN translation and identify potential targets for treating repeat‐associated neurodegeneration.SynopsisFragile X‐associated tremor/ataxia syndrome is caused by CGG repeat‐associated non‐AUG (RAN) translation that initiates within the 5′UTR of FMR1. A candidate‐based screen identified several initiation factors—DDX3X/Belle, eIF4B, eIF4H, eIF1, and eIF5—critical for FMR1 RAN translation.Knockdown of the RNA helicase DDX3X selectively suppresses FMR1 RAN translation in Drosophila melanogaster, cultured HeLa cells, and in vitro translation assays.DDX3X knockdown reduces CGG repeat‐associated toxicity in Drosophila and mammalian neurons.Eukaryotic initiation factors that modulate RNA‐RNA secondary structure (DDX3X, EIF4B, EIF4H) or start codon fidelity (EIF1, EIF5) impact FMR1 RAN translation.FXTAS is caused by CGG repeat‐associated non‐AUG (RAN) translation that initiates within the 5′UTR of FMR1. A candidate‐based screen identified several initiation factors—DDX3X/Belle, eIF4B, eIF4H, eIF1, and eIF5—critical for FMR1 RAN translation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151325/1/embr201847498.reviewer_comments.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151325/2/embr201847498-sup-0001-Appendix.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151325/3/embr201847498_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151325/4/embr201847498.pd

Dietary isoflavone and the risk of colorectal adenoma: a case–control study in Japan

We conducted a case–control study in a Japanese population to investigate the association between dietary isoflavone intake and the risk of colorectal adenoma. Participants who underwent magnifying colonoscopy with dye spreading as part of a cancer screening programme responded to a self-administered questionnaire, which included lifestyle information and intake of 145 food items, before the colonoscopy. A total of 721 case and 697 control subjects were enrolled. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models. We found a significant inverse association between dietary isoflavone intake and the risk of colorectal adenoma in men and women combined. However, the inverse association was not linear; rather, all quartiles above the first showed a similar decrease in risk, with multivariable-adjusted ORs and 95% CIs compared with the lowest quartile of 0.77 (0.57–1.04), 0.76 (0.56–1.02) and 0.70 (0.51–0.96) in the second, third and highest quartiles, respectively (P for trend=0.03). Of interest, the observed association was more prominent in women than in men. The observed ceiling effect associated with higher isoflavone intake suggests that a lower intake of dietary isoflavone might be associated with an increased risk of colorectal adenoma in Japanese populations