replication catastrophe
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OBJECTIVES: Flubendazole (FLU), a member of benzimidazole family of anthelmintic drugs, is able to inhibit proliferation of various cancer cells. The aim of present study was to elucidate the mechanisms of antiproliferative effect of FLU on colorectal cancer cells in vitro. METHODS: The effect of FLU on proliferation, microtubular network, DNA content, caspase activation and senescence induction was studied in SW480 and SW620 cell lines. KEY FINDINGS: Flubendazole significantly affected cell proliferation in a pattern typical for mitotic inhibitor. This was accompanied by decrease in cyclin D1 levels, increase in cyclin B1 levels, activation of caspase 2 and caspase 3/7 and PARP cleavage. Morphological observations revealed disruption of microtubular network, irregular mitotic spindles, formation of giant multinucleated cells and increase in nuclear area and DNA content. In SW620 cell line, 37.5% giant multinucleated cells induced by FLU treatment showed positivity for SA-β-galactosidase staining. Cell lines were able to recover from the treatment and this process was faster in SW480 cells. CONCLUSION: Flubendazole in low concentration temporarily inhibits cell proliferation and induces mitotic catastrophe and premature senescence in human colon cancer cells in vitro.
- MeSH
- aparát dělícího vřeténka účinky léků ultrastruktura MeSH
- lidé MeSH
- mebendazol analogy a deriváty farmakologie MeSH
- mikrotubuly účinky léků ultrastruktura MeSH
- mitóza účinky léků MeSH
- nádorové buněčné linie MeSH
- obrovské buňky účinky léků ultrastruktura MeSH
- proliferace buněk účinky léků MeSH
- stárnutí buněk účinky léků MeSH
- tubulin metabolismus MeSH
- velikost buněčného jádra účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cellular mechanisms that safeguard genome integrity are often subverted in cancer. To identify cancer-related genome caretakers, we employed a convergent multi-screening strategy coupled to quantitative image-based cytometry and ranked candidate genes according to multivariate readouts reflecting viability, proliferative capacity, replisome integrity, and DNA damage signaling. This unveiled regulators of replication stress resilience, including components of the pre-mRNA cleavage and polyadenylation complex. We show that deregulation of pre-mRNA cleavage impairs replication fork speed and leads to excessive origin activity, rendering cells highly dependent on ATR function. While excessive formation of RNA:DNA hybrids under these conditions was tightly associated with replication-stress-induced DNA damage, inhibition of transcription rescued fork speed, origin activation, and alleviated replication catastrophe. Uncoupling of pre-mRNA cleavage from co-transcriptional processing and export also protected cells from replication-stress-associated DNA damage, suggesting that pre-mRNA cleavage provides a mechanism to efficiently release nascent transcripts and thereby prevent gene gating-associated genomic instability.
- MeSH
- aktivní transport - buněčné jádro MeSH
- DNA nádorová genetika metabolismus MeSH
- HeLa buňky MeSH
- heteroduplexy nukleové kyseliny genetika metabolismus MeSH
- jaderné proteiny genetika metabolismus MeSH
- lidé MeSH
- messenger RNA biosyntéza genetika MeSH
- nádory genetika metabolismus MeSH
- nestabilita genomu * MeSH
- polyadenylace MeSH
- poškození DNA * MeSH
- prekurzory RNA biosyntéza genetika MeSH
- proteiny buněčného cyklu genetika metabolismus MeSH
- regulace genové exprese u nádorů MeSH
- replikace DNA * MeSH
- RNA nádorová biosyntéza genetika MeSH
- štěpení RNA * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Ionizing radiation (IR) induces various types of damage in the cellular DNA, of which the most deleterious are double strand breaks. Double strand breaks lead to activation of signaling cascade aiming to repair the damage or to transiently or permanently arrest cell cycle, and/or induce cell death. In the case of high doses of ionizing radiation with a high dose-rate (0.5-1 Gy / min) where the cell repair capacity is insufficient, cell death often occurs in response to double-strand breaks. The response to the radiation exposure depends on many factors such as the cell type, its proliferation activity, and p53 status. In tumor cells, cell death is associated primarily with apoptosis or mitotic catastrophe. In normal fibroblasts, cells accumulate in the G1-phase of the cell cycle and so-called premature senescence occurs after irradiation. In cells with functional p53 protein an increase in the p21 protein (cell division inhibitor) and accumulation of the cells in the G1-phase occurs. In the case of very low-dose rate (LDR), this accumulation is transient; after DNA damage repair, the cells continue to divide. Upon irradiation with higher doses at a LDR, accumulation in the G1-phase is irreversible; p16 protein is upregulated and the status of premature senescence is induced. The same dose of radiation administered at LDRs results in more senescence than after an acute exposure. In the case of the use of IR for the eradication of tumor cells, the status of these cells is important in terms of p53 and proliferation. About fifty percent of tumor cells do not possess p53 protein or are mutant, and after irradiation they accumulate in the G2-phase and repair the IR-induced damage (e.g. HL-60 cells). In HL-60 cells (p53-/- human promyelocytic leukemia), G2-phase accumulation occurs during irradiation with low dose rate, and their radioresistance increases if the cells are irradiated in the G2-phase. When the dose-rate is very low, the cells enter the mitotic cycle during irradiation, and because cels in mitosis are highly radiosensitive, apoptosis is induced and thus their radiosensitivity increases as well.
- MeSH
- apoptóza MeSH
- buněčná smrt MeSH
- ionizující záření MeSH
- lidé MeSH
- stárnutí buněk MeSH
- vztah dávky záření a odpovědi MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH