Altered Elemental Distribution in Male Rat Brain Tissue as a Predictor of Glioblastoma Multiforme Growth-Studies Using SR-XRF Microscopy

Advancements in Image-Based Models for High-Grade Gliomas Might Be Accelerated

The first half of 2022 saw the publication of several major research advances in image-based models and artificial intelligence applications to optimize treatment strategies for high-grade gliomas, the deadliest brain tumors. We review them and discuss the barriers that delay their entry into clinical practice; particularly, the small sample size and the heterogeneity of the study designs and methodologies used. We will also write about the poor and late palliation that patients suffering from high-grade glioma can count on at the end of life, as well as the current legislative instruments, with particular reference to Italy. We suggest measures to accelerate the gradual progress in image-based models and end of life care for patients with high-grade glioma.

Bioinformatics-based dynamics of cuproptosis -related indicators in experimental silicosis

Pneumoconiosis is one of the most serious occupational diseases worldwide. Silicosis due to prolonged inhalation of free silica dust during occupational activities is one of the main types. Cuproptosis is a newly discovered mode of programmed cell death characterized by the accumulation of free copper in the cell, which ultimately leads to cell death. Increased copper in the serum of silicosis patients, suggests that the development of silicosis is accompanied by changes in copper metabolism, but whether cuproptosis is involved in the progression of silicosis is actually to be determined. To test this hypothesis, we screened the genetic changes in patients with idiopathic fibrosis by bioinformatics methods and predicted and functionally annotated the cuproptosis-related genes among them. Subsequently, we established a mouse silicosis model and detected the concentration of copper ions and the activity of ceruloplasmin (CP) in serum, as well as changes of the concentration of copper and cuproptosis related genes in mouse lung tissues. We identified 9 cuproptosis-related genes among the differential genes in patients with IPF at different times and the tissue-specific expression levels of ferredoxin 1 (FDX1) and Lipoyl synthase (LIAS) proteins. Furthermore, serum CP activity and copper ion levels in silicosis mice were elevated on days 7th and 56th after silica exposure. The expression of CP in mouse lung tissue elevated at all stages after silica exposure. The mRNA level of FDX1 decreased on days 7th and 56th, and the protein level remained in accordance with the mRNA level on day 56th. LIAS and Dihydrolipoamide dehydrogenase (DLD) levels were downregulated at all times after silica exposure. In addition, Heatshockprotein70 (HSP70) expression was increased on day 56. In brief, our results demonstrate that there may be cellular cuproptosis during the development of experimental silicosis in mice and show synchronization with enhanced copper loading in mice.

Glioblastoma multiforme influence on the elemental homeostasis of the distant organs: the results of inter-comparison study carried out with TXRF method

Glioblastoma (GBM) is a fast-growing and aggressive brain tumor which invades the nearby brain tissue but generally does not spread to the distant organs. Nonetheless, if untreated, GBM can result in patient death in time even less than few months from the diagnosis. The influence of the tumor progress on organs other than brain is obvious but still not well described. Therefore, we examined the elemental abnormalities appearing in selected body organs (kidney, heart, spleen, lung) in two rat models of GBM. The animals used for the study were subjected to the implantation of human GBM cell lines (U87MG and T98G) characterized by different levels of invasiveness. The elemental analysis of digested organ samples was carried out using the total reflection X-ray fluorescence (TXRF) method, independently, in three European laboratories utilizing various commercially available TXRF spectrometers. The comparison of the data obtained for animals subjected to T98G and U87MG cells implantation showed a number of elemental anomalies in the examined organs. What is more, the abnormalities were found for rats even if neoplastic tumor did not develop in their brains. The most of alterations for both experimental groups were noted in the spleen and lungs, with the direction of the found element changes in these organs being the opposite. The observed disorders of element homeostasis may result from many processes occurring in the animal body as a result of implantation of cancer cells or the development of GBM, including inflammation, anemia of chronic disease or changes in iron metabolism. Tumor induced changes in organ elemental composition detected in cooperating laboratories were usually in a good agreement. In case of elements with higher atomic numbers (Fe, Cu, Zn and Se), 88% of the results were classified as fully compliant. Some discrepancies between the laboratories were found for lighter elements (P, S, K and Ca). However, also in this case, the obtained results fulfilled the requirements of full (the results from three laboratories were in agreement) or partial agreement (the results from two laboratories were in agreement).

Vibrational spectroscopy methods for investigation of the animal models of glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common and devastating primary brain tumor among adults. It is highly lethal disease, as only 25% of patients survive longer than 1 year and only 5% more than 5 years from the diagnosis. To search for the new, more effective methods of treatment, the understanding of mechanisms underlying the process of tumorigenesis is needed. The new light on this problem may be shed by the analysis of biochemical anomalies of tissues affected by tumor growth. Therefore, in the present work, we applied the Fourier transform infrared (FTIR) and Raman microspectroscopy to evaluate changes in the distribution and structure of biomolecules appearing in the rat brain as a result of glioblastoma development. In turn, synchrotron X-ray fluorescence microscopy was utilized to determine the elemental anomalies appearing in the nervous tissue. To achieve the assumed goals of the study animal models of GBM were used. The rats were subjected to the intracranial implantation of glioma cells with different degree of invasiveness. For spectroscopic investigation brain slices taken from the area of cancer cells administration were used. The obtained results revealed, among others, the decrease content of lipids and compounds containing carbonyl groups, compositional and structural changes of proteins as well as abnormalities in the distribution of low atomic number elements within the region of tumor.

The applicability of Fourier transform infrared microspectroscopy for correction against matrix effects in X-ray fluorescence microimaging of tissues

X-ray fluorescence (XRF) and Fourier transform infrared (FTIR) microscopy techniques are now considered popular for rapid and label-free complementary spectrochemical analysis of chemical elements and molecular systems in biological specimens. The morphological heterogeneity but also the inhomogeneities associated with the thickness/density of biological samples demonstrate challenges for the quantitative XRF microimaging. Therefore, in the present work, we proposed for the first time the application of the total absorbance under the FTIR spectra as a mass surface correction procedure for two-dimensional (2D) XRF microimaging of tissues. We also evaluated the equivalence of the developed correction method based on total absorbance of FTIR spectra with the proposed approaches based on incoherent scattering of primary X-rays as well as on the membrane Si-Kα transmission signal, on the example of selected rat organ tissues. Thin cryo-sections taken from various organs of Wistar rats were deposited on silicon nitride membranes (Si₃N₄). The FTIR microscopy studies were performed to collect infrared absorption spectra, used then for the determination of total absorbance values in the selected areas of tissue samples. In turn, hard X-ray imaging based on synchrotron radiation allowed the determination of characteristic radiation intensities of the elements detectable from the tissue, as well as the characteristic radiation of the membrane Si and incoherently scattered X-ray photons (Compton scattering). The latter served as correction factors for the surface mass of the sample alongside the FTIR total absorbance. The qualitative and quantitative analyses showed a high agreement between the results of elemental surface mass correction using total absorbance under FTIR spectra of tissues with those obtained using surface mass correction factors determined directly from XRF spectra. Therefore, the proposed procedure is a good alternative in cases where the surface mass effect of the sample cannot be eliminated based on the information provided directly by the XRF spectrum, as in the case of using polymer films as sample support. We have also proposed a procedure for synchronizing SRXRF and FTIR images, not limited to visual inspection of imaging/mapping data, but also enabling quantitative analysis. We found that the total absorbance determined from FTIR spectra can be successfully used as a correction factor for eliminating the surface mass effect in XRF microimaging of thin freeze-fried tissues and therefore to obtain the surface mass-independent elemental quantities. The proposed approach for 2D-FTIR-XRF analysis can also be a powerful and versatile tool for fostering a correlation and co-localization analysis to search for common distribution patterns between molecular arrangements and chemical elements.