Proteomic analysis of brain metastatic lung adenocarcinoma reveals intertumoral heterogeneity and specific alterations associated with the timing of brain metastases

BACKGROUND

Brain metastases are associated with considerable negative effects on patients' outcome in lung adenocarcinoma (LADC). Here, we investigated the proteomic landscape of primary LADCs and their corresponding brain metastases.

MATERIALS AND METHODS

Proteomic profiling was conducted on 20 surgically resected primary and brain metastatic LADC samples via label-free shotgun proteomics. After sample processing, peptides were analyzed using an Ultimate 3000 pump coupled to a QExactive HF-X mass spectrometer. Raw data were searched using PD 2.4. Further data analyses were carried out using Perseus, RStudio and GraphPad Prism. Proteomic data were correlated with clinical and histopathological parameters and the timing of brain metastases. Mass spectrometry-based proteomic data are available via ProteomeXchange with identifier PXD027259.

RESULTS

Out of the 6821 proteins identified and quantified, 1496 proteins were differentially expressed between primary LADCs and corresponding brain metastases. Pathways associated with the immune system, cell-cell/matrix interactions and migration were predominantly activated in the primary tumors, whereas pathways related to metabolism, translation or vesicle formation were overrepresented in the metastatic tumors. When comparing fast- versus slow-progressing patients, we found 454 and 298 differentially expressed proteins in the primary tumors and brain metastases, respectively. Metabolic reprogramming and ribosomal activity were prominently up-regulated in the fast-progressing patients (versus slow-progressing individuals), whereas expression of cell-cell interaction- and immune system-related pathways was reduced in these patients and in those with multiple brain metastases.

CONCLUSIONS

This is the first comprehensive proteomic analysis of paired primary tumors and brain metastases of LADC patients. Our data suggest a malfunction of cellular attachment and an increase in ribosomal activity in LADC tissue, promoting brain metastasis. The current study provides insights into the biology of LADC brain metastases and, moreover, might contribute to the development of personalized follow-up strategies in LADC.

Ultrastructure of Gentiana tibetica proembryogenic cells before and after cooling treatments

The influence of increased concentrations of sucrose, 0.4 M sorbitol, DMSO and vitrification solution (PVS2) on the ultrastructure of non-frozen and frozen suspensions of Gentiana tibetica King ex Hook. F.tissue cells was investigated. Embryogenic aggregates were composed of three groups of cells of different size with various types of plastids. The ultrastructural changes resulting from increasing the sucrose concentration in the medium from 3 to 6 percent for 4 weeks and from treatment with 0.4 M sorbitol for 48 h were similar. Observations showed replacement of large vacuoles by numerous small ones, condensation of cytoplasm, accumulation of starch, and fragmentation of endoplasmic reticulum. Treatment with PVS2 led to degradation of starch, coalescence of amyloplasts and to shrinking of nucleoli from the third group of cells when originating from 6 percent sucrose medium. The mitochondria initially had various shapes, but after PVS2 treatment showed only spherical shapes with sparse cristae. After programmed freezing of tissue protected by sorbitol and DMSO, lethal damage was observed: membrane and nuclei degradation, and cell destruction. Reversible changes after freezing were observed in tissue pretreated with vitrification solution: dilation of cell membranes, mitochondria with electron-lucent vessels, aggregation of numerous vesicles, and degradation of starch in amyloplasts. In cells cooled by a vitrification method, cell organelles appeared normal as early as 5 h after thawing, and anomalies were not observed after 48 h of post-thawing culture.

Perturbation in linker histone content has no effect on the cell cycle but affects the cell size of suspension grown tobacco BY-2 cells

Histone H1, a key structural element of eukaryotic chromosomes can be perturbed in plants in vivo by overexpression or by a change in the proportion of native H1 variants (Prymakowska-Bosak M., Przewloka M., Iwkiewicz J., Egierszdorff S., Kuras M., Chaubert N., Gigot C., Spiker S., Jerzmanowski A., Histone H1 overexpressed to high level in tobacco affects certain developmental programs but has limited effect on basal cellular functions, Proc. Natl. Acad. Sci. U.S.A. 93 (1996) 10250-10255; Prymakowska-Bosak M., Slusarczyk J., Przewloka M., Kuras M., Lichota J., Kilianczyk B., Jerzmanowski A., Linker Histones Play a Role in Male Meiosis and the Development of Pollen Grains in Tobacco, Plant Cell 11 (1999) 2317-2330). In order to analyze the possible causes of the specific phenotypic changes observed in whole plants we employed a simpler system of tobacco BY-2 cell line. We show that the BY-2 cells engineered to overexpress a major variant of Arabidopsis H1 or with the level of native major variants of H1 decreased by antisense strategy maintain the normal ability to grow and the normal length of the cell cycle. In the cells with perturbed H1 histones no change was observed in the organization of mitotic spindle or actin filaments of the cytoskeleton. The only visible phenotypic change occurred in cells overexpressing H1 that showed an increased frequency of cells with unusually large size. This phenotype was correlated with subtle but reproducible changes in the organization of cortical microtubules.

Structural and ultrastructural analysis of root primordia in vitro cultures (RPC) of Solanum lycopersicoides Dun

The structure and ultrastructure of cell aggregates and derived root primordia were analysed in established suspension cultures of Solanum lycopersicoides Dun. A total of four modified Murashige and Skoog (1962) (MS) media were used, two containing alpha-naphthaleneacetic acid (NAA) and two containing 2,4-dichlorophenoxyacetic acid (2,4-D). Considerable differences were observed in the size and structure of the aggregates regardless of the medium. The largest aggregates had a four-zone structure (cover, starch, dividing and differentiation zones) with distinct ultrastructural organization. The degree of histological and ultrastructural differentiation in the aggregates indicated rhizogenesis initiation. It begins with the protrusion of mounds of root primordia, which are the result of radial growth of cells in defined zones of the aggregate. Further growth from the primordium forms a root meristem with three tiers initial centre and wholly distinguished histogens (dermatogen, periblem, plerome). Rhizogenesis was more regular on media with NAA than on media with 2,4-D. Primordia and fully organized roots were liberated due to fragmentation of the aggregate and underwent changes in the permanently active developmental cycle of the culture which gave rise to successive generations of aggregates. Growth regulators had different influences on the organellar composition and phenolic compounds presence in the different zones of aggregates.

SP., isolated from gypsy moths (Lymantria dispar L.) collected in portugal

A microsporidium Nosema portugal n. sp. was isolated from gypsy moths, Lymantria dispar L, collected near Lisbon, Portugal, in 1985. The life cycle includes two sequential developmental cycles, a primary and a secondary cycle. The primary cycle occurs in midgut epithelial cells, where primary spores are produced within 48 h. The primary spores immediately extrude their polar filaments, presumably to infect other cells. In the target tissues (salivary glands and fat body) the secondary development cycle is followed by the formation of environmental spores. Primary spores were also sometimes present in target tissues. Fresh unfixed and unstained primary spores have a large posterior vacuole and measured 4.8 x 2.7 &mgr;m. Ultrastructurally, they have 5-8 polar filament coils, a large posterior vacuole, abundant endoplasmic reticulum, and were binucleate. Mature unfixed and unstained environmental spores were highly refractive and the posterior vacuole and nuclei could not be seen through the spore coat. Fresh environmental spores measured 4.5 x 1.9 &mgr;m. Ultrastructurally, environmental spores were binucleate, with a typical polaroplast, 10-11 isofilar polar filament coils, and a series of 4-6 thin polar filament-like tubules situated at the posterior end of the row of typical polar filament coils. The ssu rRNA sequences strongly suggest that this species is more closely related to the Vairimorpha subgroup within the Nosema/Vairimorpha clade than to the Nosema subgroup. Copyright 1999 Academic Press.