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Potapov, A.

Publications and source records attributed to Potapov, A..

2 recordsLinked to original sources

Different localization of fluorescently labeled N- and C-termini of nucleolin variants in human glioblastoma cell culture

Nucleolus-oriented protein nucleolin plays a significant role in the life of a normal mammalian cell. However, nucleolin is also actively expressed in cells of malignant tumors. At the same time, its expression in different types of cancer is significantly increased compared with normal cells. It is interesting that nucleolin localization often varies in tumor cells, namely in the cytoplasm and on the cell membrane. This fact is considered to be a poor prognostic indicator. This work is devoted to the study of the distribution of nucleolin in human glioblastoma cells. Glioblastoma is one of the most aggressive malignant tumors with an absolutely unfavorable prognosis. These tumors have a high proliferative potential, but in addition they are often characterized by invasive properties. Research on lineage cells does not let to fully study these properties of glioblastoma, since lineage cells are very different from the actual tumor. In our study, we used two primary cell cultures of human glioblastoma with varying degrees of invasiveness of the original tumors. The main interest was directed at studying the localization of nucleolin and its correlation with the invariability of the N- and C-termini of the corresponding protein. Particular attention was paid to the significance of the unaltered C-terminus of nucleolin for its distribution in the cells of transplanted human glioblastoma cultures derived from patient tissues.\n\nThe aim of this work is to find the relationship between the deformation of the N- or C-terminal sequences of nucleolin and its localization.We showed that in glioblastoma cells, with a high degree of invasion, nucleolin is found in the cytoplasm and close to the cell membrane, and the distribution of nucleolin with undeformed C and N-terminal does not match.

cancer biology

Trophic consistency of supraspecific taxa in belowground invertebrate communities

1. Animals that have similar morphological traits are expected to share similar ecological niches. This statement applies to individual animals within a species and thus species often serve as the functional units in ecological studies. Species are further grouped into higher-ranked taxonomic units based on their morphological similarity and thus are also expected to be ecologically similar. On the other hand, theory predicts that strong competition between closely related species can lead to differentiation of ecological niches. Due to a high diversity and limited taxonomic expertise, soil food webs are often resolved using supraspecific taxa such as families, orders or even classes as functional units.\n\n2. Here we for the first time empirically tested the trophic consistency of supraspecific taxa across major lineages of temperate forest soil invertebrates: Annelida, Chelicerata, Myriapoda, Crustacea and Hexapoda. Published data on stable isotope compositions of carbon and nitrogen were used to infer basal resources and trophic level, and explore the relationship between taxonomic and trophic dissimilarity of local populations.\n\n3. Genera and families had normal and unimodal distributions of isotope niches, suggesting that supraspecific taxa are trophically consistent. The isotopic niche of populations across different localities is better predicted by species than by supraspecific taxa. However, within the same genus, the effect of species identity on stable isotope composition of populations was not significant in 92% of cases. The link to basal resources, i.e. plants or detritus, was convergent in different lineages, while trophic levels followed the Brownian motion taxonomic model. Virtually none of the studied taxa showed pronounced trophic niche conservatism within a lineage.\n\n4. Supraspecific taxa are meaningful as functional units in ecological studies, but the consistency varies among taxa and thus the choice of taxonomic resolution depends on the research question; generally, identification of taxa should be more detailed in more diverse taxonomic groups. We compiled a comprehensive list of mean {Delta}13C and {Delta}15N values of invertebrate taxa from temperate forest soils allowing to refine soil food-web models when identification to species level is not feasible.

ecology