Fragmentation of nucleoli in senescent cancer cells is associated with increased levels of polyadenylated transcripts derived from noncoding regions of rDNA units

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081707%3A_____%2F25%3A00644597" target="_blank" >RIV/68081707:_____/25:00644597 - isvavai.cz</a>

Výsledek na webu

<a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC12678568/" target="_blank" >https://pmc.ncbi.nlm.nih.gov/articles/PMC12678568/</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00249-025-01773-9" target="_blank" >10.1007/s00249-025-01773-9</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Fragmentation of nucleoli in senescent cancer cells is associated with increased levels of polyadenylated transcripts derived from noncoding regions of rDNA units

Popis výsledku v původním jazyce

In this study, we investigated the behavior of rDNA loci in senescent MCF-7 mammary cancer cells induced by gamma irradiation. To analyze changes in nucleolar structure we used rDNA-FISH and immunohistochemical staining with fibrillarin and UBF transcription factor. The expression levels of rDNAs and nucleolar proteins were determined by RNA-seq of total and poly-A libraries. The cytological and molecular parameters of nucleoli were monitored throughout the 7-day interval following irradiation. Senescent cells exhibited a higher proportion of smaller nucleoli as compared to cycling cells, indicating nucleolar fragmentation. The rDNA copy number and expression of rDNA variants remained stable in cycling and senescent cells. However, the levels of polyadenylated rRNA species derived from external (5 ' ETS) and internal (ITS1) rDNA spacers tend to increase (c.2 fold) following irradiation. At the protein level, senescent cells showed decreased levels of fibrillarin and UBF transcription factor while localization of both proteins in the nucleolus was not impaired. We conclude that withdrawal from cell cycle does not change expression patterns of rDNA variants. However, defects in rRNA processing may lead to fragmentation of nucleoli in senescent cells.

Název v anglickém jazyce

Fragmentation of nucleoli in senescent cancer cells is associated with increased levels of polyadenylated transcripts derived from noncoding regions of rDNA units

Popis výsledku anglicky

In this study, we investigated the behavior of rDNA loci in senescent MCF-7 mammary cancer cells induced by gamma irradiation. To analyze changes in nucleolar structure we used rDNA-FISH and immunohistochemical staining with fibrillarin and UBF transcription factor. The expression levels of rDNAs and nucleolar proteins were determined by RNA-seq of total and poly-A libraries. The cytological and molecular parameters of nucleoli were monitored throughout the 7-day interval following irradiation. Senescent cells exhibited a higher proportion of smaller nucleoli as compared to cycling cells, indicating nucleolar fragmentation. The rDNA copy number and expression of rDNA variants remained stable in cycling and senescent cells. However, the levels of polyadenylated rRNA species derived from external (5 ' ETS) and internal (ITS1) rDNA spacers tend to increase (c.2 fold) following irradiation. At the protein level, senescent cells showed decreased levels of fibrillarin and UBF transcription factor while localization of both proteins in the nucleolus was not impaired. We conclude that withdrawal from cell cycle does not change expression patterns of rDNA variants. However, defects in rRNA processing may lead to fragmentation of nucleoli in senescent cells.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10610 - Biophysics

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

European Biophysics Journal With Biophysics Letters

ISSN

0175-7571

e-ISSN

1432-1017

Svazek periodika

54

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

11

Strana od-do

613-623

Kód UT WoS článku

001513459500001

EID výsledku v databázi Scopus

2-s2.0-105008822742