Vitamin D receptor and progesterone receptor protein and gene expression in papillary thyroid carcinomas: associations with histological features

PURPOSE

Vitamin D receptor (VDR) and progesterone receptor (PR) expression has been described in papillary thyroid carcinoma (PTC) but data regarding association with tumor histological characteristics and localization of the protein expression are scarce.

MATERIALS AND METHODS

Formalin-fixed, paraffin-embedded specimens from 45 patients with PTC (cases) were retrieved and tumor histological data were recorded. We analyzed gene and protein expression of VDR and PR and gene expression of vitamin D-inactivating 24-hyroxylase (CYP24A1) and the activating 1-alpha-hydroxylase (CYP27B1) enzymes in follicular cancer cells and the adjacent non-neoplastic thyroid tissue (NNTT).

RESULTS

VDR mRNA and protein expression was higher in PTC compared with NNTT (p < 0.05). The protein was globally localized in the cytoplasm and cell membranes of the neoplastic cells in all cases, with differences in intensity. Cytoplasmic positivity was stronger in the majority of cases. Membranous positivity was also evident in cases, whereas in NNTT was generally weak and in a low percentage of the cells. Expression of CYP 24A1, but not CYP27B1, was increased in approximately all PTC specimens and was associated with lymph node metastasis and extrathyroidal extension. PR mRNA was increased in 34% and protein expression was present in 57% of cases, and none of NNTT. PR, but not VDR, mRNA expression was significantly associated with the tumor size (r = 0.645, p = 0.007).

CONCLUSIONS

We provide evidence for the expression pattern of VDR, PR and CYP24A1 in the progression of PTC. Rapid anti-tumor responses of vitamin D in PTC may be blocked due to inactivation of local vitamin D metabolism.

A metagenomic study of the preventive effect of Lactobacillus rhamnosus GG on intestinal polyp formation in ApcMin/+ mice

AIMS

To investigate the in vivo effects of Lactobacillus rhamnosus GG (LGG) on intestinal polyp development and the interaction between this single-organism probiotic and the gut microbiota therein.

METHODS AND RESULTS

The Apc^Min/+ mouse model was used to study the potential preventive effect of LGG on intestinal polyposis, while shotgun metagenomic sequencing was employed to characterize both taxonomic and functional changes within the gut microbial community. We found that the progression of intestinal polyps in the control group altered the community functional profile remarkably despite small variation in the taxonomic diversity. In comparison, the consumption of LGG helped maintain the overall functional potential and taxonomic profile in the resident microbes, thereby leading to a 25% decrease of total polyp counts. Furthermore, we found that LGG enriched those microbes or microbial activities related to short-chain fatty acid production (e.g. Roseburia and Coprococcus), as well as suppressed the ones that can lead to inflammation (e.g. Bilophila wadsworthia).

CONCLUSIONS

Our study using shotgun metagenomics highlights how single probiotic LGG may exert its beneficial effects and decrease polyp formation in mice by maintaining gut microbial functionality.

SIGNIFICANCE AND IMPACT OF THE STUDY

This probiotic intervention targeting microbiota may be used in conjugation with other dietary supplements or drugs as part of prevention strategies for early-stage colon cancer, after further clinical validations in human.

Leptin administration in physiological or pharmacological doses does not alter circulating irisin levels in humans

Leptin is an adipokine causing browning of adipose tissue, and it thus increases energy expenditure. The same is true for irisin. We studied whether exogenously administered metreleptin affects serum irisin concentrations in humans, which would suggest a direct interplay between leptin and irisin. We performed two studies: a dose-escalating 1-day-long study and a randomized placebo-controlled study. Study 1: 15 healthy, normal-weight and/or obese male and female individuals participated in three 1-day-long trials of metreleptin administration in the fed state. Metreleptin was administered once at physiological and pharmacological (0.01, 0.1 and 0.3 mg per kg body weight) doses. Study 2: 18 apparently healthy hypoleptinemic young women with hypoleptinemia and secondary amenorrhea took part in this study. Subjects received either metreleptin in replacement doses (0.08 and/or 0.12 mg kg(-1)) or placebo for 16 weeks. Blood samples were analyzed for leptin and irisin. We found no effect of metreleptin administration on irisin levels of subjects studied at either the fasting or the fed state either in the short or the long term. We provide evidence that leptin is not altering circulating irisin levels in humans.

The impact of network biology in pharmacology and toxicology

With the need to investigate alternative approaches and emerging technologies in order to increase drug efficacy and reduce adverse drug effects, network biology offers a novel way of approaching drug discovery by considering the effect of a molecule and protein's function in a global physiological environment. By studying drug action across multiple scales of complexity, from molecular to cellular and tissue level, network-based computational methods have the potential to improve our understanding of the impact of chemicals in human health. In this review we present the available large-scale databases and tools that allow integration and analysis of such information for understanding the properties of small molecules in the context of cellular networks. With the recent advances in the omics area, global integrative approaches are necessary to cope with the massive amounts of data, and biomedical researchers are urged to implement new types of analyses that can lead to new therapeutic interventions with increased safety and efficacy compared with existing medications.

Physiological characterization of xylose metabolism inAspergillus niger under oxygen-limited conditions

The physiology of Aspergillus niger was studied under different aeration conditions. Five different aeration rates were investigated in batch cultivations of A. niger grown on xylose. Biomass, intra- and extra-cellular metabolites profiles were determined and ten different enzyme activities in the central carbon metabolism were assessed. The focus was on organic acid production with a special interest in succinate production. The fermentations revealed that oxygen limitation significantly changes the physiology of the micro-organism. Changes in extra cellular metabolite profiles were observed, that is, there was a drastic increase in polyol production (erythritol, xylitol, glycerol, arabitol, and mannitol) and to a lesser extent in the production of reduced acids (malate and succinate). The intracellular metabolite profiles indicated changes in fluxes, since several primary metabolites, like the intermediates of the TCA cycle accumulated during oxygen limitation (on average three fold increase). Also the enzyme activities showed changes between the exponential growth phase and the oxygen limitation phase. In general, the oxygen availability has a significant impact on the physiology of this fungus causing dramatic alterations in the central carbon metabolism that should be taken into account in the design of A. niger as a succinate cell factory.