👤 Waltraud Hubert

Glioblastoma (GBM) displays marked cellular and metabolic heterogeneity that varies among cellular microenvironments within a tumor. Metabolic targeting has long been advocated as a therapy against many tumors including GBM, but how lipid metabolism is altered to suit different microenvironmental conditions and whether cancer stem cells (CSCs) have altered lipid metabolism are outstanding questions in the field. We interrogated gene expression in separate microenvironments of GBM organoid models that mimic the transition between nutrient-rich and nutrient-poor pseudopalisading/perinecrotic tumor zones using spatial-capture RNA-sequencing. We revealed a striking difference in lipid processing gene expression and total lipid content between diverse cell populations from the same patient, with lipid enrichment in hypoxic organoid cores and also in perinecrotic and pseudopalisading regions of primary patient tumors. This was accompanied by regionally restricted upregulation of hypoxia-inducible lipid droplet-associated (HILPDA) gene expression in organoid cores and pseudopalisading regions of clinical GBM specimens, but not lower-grade brain tumors. CSCs have low lipid droplet accumulation compared to non-CSCs in organoid models and xenograft tumors, and prospectively sorted lipid-low GBM cells are functionally enriched for stem cell activity. Targeted lipidomic analysis of multiple patient-derived models revealed a significant shift in lipid metabolism between GBM CSCs and non-CSCs, suggesting that lipid levels may not be simply a product of the microenvironment but also may be a reflection of cellular state. CSCs had decreased levels of major classes of neutral lipids compared to non-CSCs, but had significantly increased polyunsaturated fatty acid production due to high fatty acid desaturase (FADS1/2) expression which was essential to maintain CSC viability and self-renewal. Our data demonstrate spatially and hierarchically distinct lipid metabolism phenotypes occur clinically in the majority of patients, can be recapitulated in laboratory models, and may represent therapeutic targets for GBM. Show less

The basic understanding of the biological effects of eukaryotic translation initiation factors (EIFs) remains incomplete, notably for their roles independent of protein translation. Different EIFs exhibit nuclear localization and DNA-related functions have been proposed, but the understanding of EIFs novel functions beyond protein translation lacks of integrative analyses between the genomic and the proteomic levels. Here, the noncanonical function of EIF3F was studied in human lung adenocarcinoma by combining methods that revealed both the protein-protein and the protein-DNA interactions of this factor. We discovered that EIF3F promotes cell metastasis in vivo. The underpinning molecular mechanisms involved the regulation of a cluster of 34 metastasis-promoting genes including Snail2, as revealed by proteomics combined with immuno-affinity purification of EIF3F and ChIP-seq/Q-PCR analyses. The interaction between EIF3F and signal transducer and activator of transcription 3 (STAT3) controlled the EIF3F-mediated increase in Snail2 expression and cellular invasion, which were specifically abrogated using the STAT3 inhibitor Nifuroxazide or knockdown approaches. Furthermore, EIF3F overexpression reprogrammed energy metabolism through the activation of AMP-activated protein kinase and the stimulation of oxidative phosphorylation. Our findings demonstrate the role of EIF3F in the molecular control of cell migration, invasion, bioenergetics, and metastasis. The discovery of a role for EIF3F-STAT3 interaction in the genetic control of cell migration and metastasis in human lung adenocarcinoma could lead to the development of diagnosis and therapeutic strategies. Show less

Anacetrapib is an inhibitor of cholesteryl ester transfer protein (CETP) previously under development as a lipid-modifying agent that reduces LDL-cholesterol and increases HDL-cholesterol in hypercholesterolemic patients. Anacetrapib demonstrates a long terminal half-life and accumulates in adipose tissue, which contributes to a long residence time of anacetrapib. Given our previous report that anacetrapib distributes into the lipid droplet of adipose tissue, we sought to understand whether anacetrapib affected adipose function, using a diet-induced obese (DIO) mouse model. Following 20 weeks of treatment with anacetrapib (100 mg/kg/day), levels of the drug increased to approximately 0.6 mmol/L in white adipose tissue. This level of anacetrapib was not associated with any impairment in adipose functionality as evidenced by a lack of any reduction in biomarkers of adipose functionality (plasma adiponectin, leptin, insulin; adipose adiponectin, leptin mRNA). In DIO wild-type (WT) mice treated with anacetrapib for 2 weeks and then subjected to 30% food restriction during washout to induce weight loss (18%) and fat mass loss (7%), levels of anacetrapib in adipose and plasma were not different between food restricted and ad lib-fed mice. These data indicate that despite deposition and long-term residence of ~0.6 mmol/L levels of anacetrapib in adipose tissue, adipose tissue function appears to be unaffected in mice. In addition, these data also indicate that even with severe caloric restriction and acute loss of fat mass, anacetrapib does not appear to be mobilized from the fat depot, thereby solidifying the role of adipose as a long-term storage site of anacetrapib. Show less

The objective of this study was to establish an ophthalmologic phenotype of heterozygous carriers of juvenile neuronal ceroid lipofuscinosis (CLN3 disease, Batten disease). The eyes and vision of nine heterozygous carriers of juvenile neuronal ceroid lipofuscinosis with classical CLN3 mutations were examined using the following methods: clinical examination, visual acuity, ophthalmoscopy, optical coherence tomography (macular thickness and peripapillary retinal nerve fibre layer measurement [RNFL]), fundus autofluorescence measurement, infrared imaging, and full-field and multifocal electroretinogram. Optical coherence tomography and electrophysiological data were statistically compared with age- and sex-matched control groups. The basic clinical examination as well as the fundus autofluorescence and infrared images of the macular region were unremarkable. Neither the electrophysiological examinations nor optical coherence tomography yielded fundamental abnormalities. There were only two significant-albeit most likely clinically irrelevant-differences that occurred in comparison to the control group: a decrease in RNFL of the nasal quadrant in the OCT and a prolongation of the N1 implicit time of the second-ring eccentricity in the multifocal electroretinogram. The eyes and vision of heterozygous carriers of CLN3 disease showed normal features when compared to a control group, which controverts a previously suggested retinal dysfunction in these subjects. Show less

In Poland, tobacco smoking by women in a procreational age as well as the pregnant women is a common phenomenon. The aim of the conducted research was to assess the usefulness of cotinine markers in different biological materials--mother and newborn's urine, cord blood se. rum, placenta--as a biomarker of tobacco smoking by delivering women, and dependence between these biomarkers and the newborn's health state. 218 pregnant women (117 smokers and 101 non-smokers), who were checked in at the Perinatology and Gynecology Clinic of the University of Medical Sciences in Poznan, took part in the first stage of the research (period between the twelfth and sixteenth week of pregnancy) carried out between years 2004-2006. In the second stage, 201 pairs of women (89 smokers and 112 non-smokers) and their newborns were checked after the women came to hospital to deliver. The research that was conducted showed that both cotinine in the urine of delivering women and in the urine of newborns as well as in the cord blood serum may be used as a biomarker of exposure of a foetus to tobacco smoke. For practical reasons, it must be assumed that the delivering women urine should be the material from choice. The research did not indicate the usefulness of the determination of cotinine in the placenta, in order to assess the exposure of the foetus to the components of tobacco smoke. On the other hand, again it confirmed the influence of tobacco smoking on the newborn's birth parameters, a correlation between the birth weight, body length and cotinine concentration in the urine of a mother makes it possible to predict the lowering of the antropometric parameters of the newborn as a result of tobacco smoking by pregnant women. Show less