The most commonly used flow cytometric (FCM) analysis of cellular DNA content relies on ethanol fixation followed by RNA digestion and propidium iodide (PI) intercalation into double-stranded DNA. This is a laborious and time-consuming procedure that is subject to systematic errors due to centrifugation and washing steps associated with sample preparation. It can adversely affect the reliability of the results. Here, we present a modified concept of DNA quantification in adherent cell lines by FCM that involves neither ethanol fixation nor any washing and cell transferring steps. Our high throughput assay of adherent cell lines reduces sample-processing time, requires minimal workload, provides a possibility for automation, and, if needed, also allows a significant reduction in the size of individual samples. Working with a well-proven commercial tool-The BD CycletestTM Plus DNA Reagent Kit-primarily designed for cell cycle analysis and aneuploidy determination in experimental and clinical samples, we suggest a novel, very efficient, and robust approach for DNA research in adherent cell cultures.
- MeSH
- aneuploidie MeSH
- automatizace MeSH
- buněčná adheze MeSH
- buněčný cyklus genetika MeSH
- DNA * analýza MeSH
- lidé MeSH
- průtoková cytometrie * metody MeSH
- reprodukovatelnost výsledků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Differentiation is a central aspect of the parasite life cycle and encompasses adaptation to both host and environment. If we accept that evolution cannot anticipate an organism's needs as it enters a new environment, how do parasite differentiation pathways arise? The transition between vertebrate and insect stage African trypanosomes is probably one of the better studied and involves a cell-cycle arrested or 'stumpy' form that activates metabolic pathways advantageous to the parasite in the insect host. However, a range of stimuli and stress conditions can trigger similar changes, leading to formation of stumpy-like cellular states. We propose that the origin and optimisation of this differentiation program represents repurposing of a generic stress response to gain considerable gain-of-fitness associated with parasite transmission.
The onset of an early development is, in mammals, characterized by profound changes of multiple aspects of cellular morphology and behavior. These are including, but not limited to, fertilization and the merging of parental genomes with a subsequent transition from the meiotic into the mitotic cycle, followed by global changes of chromatin epigenetic modifications, a gradual decrease in cell size and the initiation of gene expression from the newly formed embryonic genome. Some of these important, and sometimes also dramatic, changes are executed within the period during which the gene transcription is globally silenced or not progressed, and the regulation of most cellular activities, including those mentioned above, relies on controlled translation. It is known that the blastomeres within an early embryo are prone to chromosome segregation errors, which might, when affecting a significant proportion of a cell within the embryo, compromise its further development. In this review, we discuss how the absence of transcription affects the transition from the oocyte to the embryo and what impact global transcriptional silencing might have on the basic cell cycle and chromosome segregation controlling mechanisms.
- MeSH
- buněčný cyklus genetika MeSH
- chromatin genetika MeSH
- embryo savčí fyziologie MeSH
- embryonální vývoj genetika MeSH
- genetická transkripce genetika MeSH
- lidé MeSH
- segregace chromozomů genetika MeSH
- umlčování genů fyziologie MeSH
- vývojová regulace genové exprese genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Background: The links between the p53/MDM2 pathway and the expression of pro-oncogenic immune inhibitory receptors in tumor cells are undefined. In this report, we evaluate whether there is p53 and/or MDM2 dependence in the expression of two key immune receptors, CD276 and PD-L1. Methods: Proximity ligation assays were used to quantify protein-protein interactions in situ in response to Nutlin-3. A panel of p53-null melanoma cells was created using CRISPR-Cas9 guide RNA mediated genetic ablation. Flow cytometric analyses were used to assess the impact of TP53 or ATG5 gene ablation, as well as the effects of Nutlin-3 and an ATM inhibitor on cell surface PD-L1 and CD276. Targeted siRNA was used to deplete CD276 to assess changes in cell cycle parameters by flow cytometry. A T-cell proliferation assay was used to assess activity of CD4+ T-cells as a function of ATG5 genotype. Results: CD276 forms protein-protein interactions with MDM2 in response to Nutlin-3, similar to the known MDM2 interactors p53 and HSP70. Isogenic HCT116 p53-wt/null cancer cells demonstrated that CD276 is induced on the cell surface by Nutlin-3 in a p53-dependent manner. PD-L1 was also unexpectedly induced by Nutlin-3, but PD-L1 does not bind MDM2. The ATM inhibitor KU55993 reduced the levels of PD-L1 under conditions where Nutlin-3 induces PD-L1, indicating that MDM2 and ATM have opposing effects on PD-L1 steady-state levels. PD-L1 is also up-regulated in response to genetic ablation of TP53 in A375 melanoma cell clones under conditions in which CD276 remains unaffected. A549 cells with a deletion in the ATG5 gene up-regulated only PD-L1, further indicating that PD-L1 and CD276 are under distinct genetic control. Conclusion: Genetic inactivation of TP53, or the use of the MDM2 ligand Nutlin-3, alters the expression of the immune blockade receptors PD-L1 and CD276. The biological function of elevated CD276 is to promote altered cell cycle progression in response to Nutlin-3, whilst the major effect of elevated PD-L1 is T-cell suppression. These data indicate that TP53 gene status, ATM and MDM2 influence PD-L1 and CD276 paralogs on the cell surface. These data have implications for the use of drugs that target the p53 pathway as modifiers of immune checkpoint receptor expression.
- MeSH
- antigeny B7 genetika MeSH
- antigeny CD274 genetika MeSH
- buněčný cyklus účinky léků genetika MeSH
- buňky A549 MeSH
- HCT116 buňky MeSH
- imidazoly farmakologie MeSH
- lidé MeSH
- ligandy MeSH
- melanom farmakoterapie MeSH
- nádorové buněčné linie MeSH
- nádorový supresorový protein p53 genetika MeSH
- piperaziny farmakologie MeSH
- proliferace buněk účinky léků genetika MeSH
- protoonkogenní proteiny c-mdm2 genetika MeSH
- upregulace účinky léků genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Cell growth requires a high level of protein synthesis and oncogenic pathways stimulate cell proliferation and ribosome biogenesis. Less is known about how cells respond to dysfunctional mRNA translation and how this feeds back into growth regulatory pathways. The Epstein-Barr virus (EBV)-encoded EBNA1 causes mRNA translation stress in cis that activates PI3Kδ. This leads to the stabilization of MDM2, induces MDM2's binding to the E2F1 mRNA and promotes E2F1 translation. The MDM2 serine 166 regulates the interaction with the E2F1 mRNA and deletion of MDM2 C-terminal RING domain results in a constitutive E2F1 mRNA binding. Phosphorylation on serine 395 following DNA damage instead regulates p53 mRNA binding to its RING domain and prevents the E2F1 mRNA interaction. The p14Arf tumour suppressor binds MDM2 and in addition to preventing degradation of the p53 protein it also prevents the E2F1 mRNA interaction. The data illustrate how two MDM2 domains selectively bind specific mRNAs in response to cellular conditions to promote, or suppress, cell growth and how p14Arf coordinates MDM2's activity towards p53 and E2F1. The data also show how EBV via EBNA1-induced mRNA translation stress targets the E2F1 and the MDM2 - p53 pathway.
- MeSH
- buněčný cyklus genetika MeSH
- fosforylace genetika MeSH
- karcinogeneze genetika MeSH
- lidé MeSH
- messenger RNA genetika MeSH
- nádorový supresorový protein p14ARF genetika MeSH
- nádorový supresorový protein p53 genetika MeSH
- nádory genetika virologie MeSH
- onkogeny genetika MeSH
- poškození DNA genetika MeSH
- proliferace buněk genetika MeSH
- proteinové domény genetika MeSH
- protoonkogenní proteiny c-mdm2 genetika MeSH
- RRM proteiny genetika MeSH
- transkripční faktor E2F1 genetika MeSH
- tumor supresorové geny MeSH
- virus Epsteinův-Barrové genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Primary cilia play critical roles in development and disease. Their assembly and disassembly are tightly coupled to cell cycle progression. Here, we present data identifying KIF14 as a regulator of cilia formation and Hedgehog (HH) signaling. We show that RNAi depletion of KIF14 specifically leads to defects in ciliogenesis and basal body (BB) biogenesis, as its absence hampers the efficiency of primary cilium formation and the dynamics of primary cilium elongation, and disrupts the localization of the distal appendage proteins SCLT1 and FBF1 and components of the IFT-B complex. We identify deregulated Aurora A activity as a mechanism contributing to the primary cilium and BB formation defects seen after KIF14 depletion. In addition, we show that primary cilia in KIF14-depleted cells are defective in response to HH pathway activation, independently of the effects of Aurora A. In sum, our data point to KIF14 as a critical node connecting cell cycle machinery, effective ciliogenesis, and HH signaling.
- MeSH
- adaptorové proteiny signální transdukční metabolismus MeSH
- aurora kinasa A antagonisté a inhibitory genetika metabolismus MeSH
- bazální tělíska metabolismus MeSH
- buněčný cyklus genetika MeSH
- chromatografie kapalinová MeSH
- cilie genetika metabolismus patologie MeSH
- HEK293 buňky MeSH
- interfáze fyziologie MeSH
- intracelulární signální peptidy a proteiny genetika metabolismus MeSH
- kineziny genetika metabolismus MeSH
- lidé MeSH
- mitóza genetika MeSH
- onkogenní proteiny genetika metabolismus MeSH
- protein-serin-threoninkinasy genetika metabolismus MeSH
- proteiny hedgehog metabolismus MeSH
- RNA interference MeSH
- signální transdukce genetika MeSH
- sodíkové kanály metabolismus MeSH
- tandemová hmotnostní spektrometrie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- biologie buňky * MeSH
- buněčná smrt fyziologie genetika MeSH
- buněčné dělení fyziologie genetika MeSH
- buněčné struktury fyziologie MeSH
- buněčný cyklus fyziologie genetika MeSH
- chromozomy fyziologie genetika MeSH
- Eukaryota fyziologie ultrastruktura MeSH
- genetické jevy fyziologie genetika MeSH
- hybridizace in situ fluorescenční MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Yeast cells must grow to a critical size before committing to division. It is unknown how size is measured. We find that as cells grow, mRNAs for some cell-cycle activators scale faster than size, increasing in concentration, while mRNAs for some inhibitors scale slower than size, decreasing in concentration. Size-scaled gene expression could cause an increasing ratio of activators to inhibitors with size, triggering cell-cycle entry. Consistent with this, expression of the CLN2 activator from the promoter of the WHI5 inhibitor, or vice versa, interfered with cell size homeostasis, yielding a broader distribution of cell sizes. We suggest that size homeostasis comes from differential scaling of gene expression with size. Differential regulation of gene expression as a function of cell size could affect many cellular processes.
- MeSH
- buněčné dělení genetika MeSH
- buněčný cyklus genetika MeSH
- cykliny genetika MeSH
- G1 fáze genetika MeSH
- regulace genové exprese u hub genetika MeSH
- Saccharomyces cerevisiae - proteiny genetika MeSH
- Saccharomyces cerevisiae genetika růst a vývoj MeSH
- velikost buňky * MeSH
- vývojová regulace genové exprese genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
The primary function of ovarian granulosa cells (GCs) is the support of oocytes during maturation and development. Molecular analyses of granulosa cell-associated processes, leading to improvement of understanding of the cell cycle events during the formation of ovarian follicles (folliculogenesis), may be key to improve the in vitro fertilization procedures. Primary in vitro culture of porcine GCs was employed to examine the changes in the transcriptomic profile of genes belonging to "cell cycle", "cell division", "cell cycle process", "cell cycle phase transition", "cell cycle G1/S phase transition", "cell cycle G2/M phase transition" and "cell cycle checkpoint" ontology groups. During the analysis, microarrays were employed to study the transcriptome of GCs, analyzing the total RNA of cells from specific periods of in vitro cultures. This research was based on material obtained from 40 landrace gilts of similar weight, age and the same living conditions. RNA was isolated at specific timeframes: before the culture was established (0 h) and after 48 h, 96 h and 144 h in vitro. Out of 133 differentially expressed genes, we chose the 10 most up-regulated (SFRP2, PDPN, PDE3A, FGFR2, PLK2, THBS1, ETS1, LIF, ANXA1, TGFB1) and the 10 most downregulated (IGF1, NCAPD2, CABLES1, H1FOO, NEK2, PPAT, TXNIP, NUP210, RGS2 and CCNE2). Some of these genes known to play key roles in the regulation of correct cell cycle passage (up-regulated SFRP2, PDE3A, PLK2, LIF and down-regulated CCNE2, TXNIP, NEK2). The data obtained provide a potential reference for studies on the process of mammalian folliculogenesis, as well as suggests possible new genetic markers for cell cycle progress in in vitro cultured porcine granulosa cells.
BACKGROUND: Androgen receptor targeted therapies have emerged as an effective tool to manage advanced prostate cancer (PCa). Nevertheless, frequent occurrence of therapy resistance represents a major challenge in the clinical management of patients, also because the molecular mechanisms behind therapy resistance are not yet fully understood. In the present study, we therefore aimed to identify novel targets to intervene with therapy resistance using gene expression analysis of PCa co-culture spheroids where PCa cells are grown in the presence of cancer-associated fibroblasts (CAFs) and which have been previously shown to be a reliable model for antiandrogen resistance. METHODS: Gene expression changes of co-culture spheroids (LNCaP and DuCaP seeded together with CAFs) were identified by Illumina microarray profiling. Real-time PCR, Western blotting, immunohistochemistry and cell viability assays in 2D and 3D culture were performed to validate the expression of selected targets in vitro and in vivo. Cytokine profiling was conducted to analyze CAF-conditioned medium. RESULTS: Gene expression analysis of co-culture spheroids revealed that CAFs induced a significant upregulation of cholesterol and steroid biosynthesis pathways in PCa cells. Cytokine profiling revealed high amounts of pro-inflammatory, pro-migratory and pro-angiogenic factors in the CAF supernatant. In particular, two genes, 3-hydroxy-3-methylglutaryl-Coenzyme A synthase 2 (HMGCS2) and aldo-keto reductase family 1 member C3 (AKR1C3), were significantly upregulated in PCa cells upon co-culture with CAFs. Both enzymes were also significantly increased in human PCa compared to benign tissue with AKR1C3 expression even being associated with Gleason score and metastatic status. Inhibiting HMGCS2 and AKR1C3 resulted in significant growth retardation of co-culture spheroids as well as of various castration and enzalutamide resistant cell lines in 2D and 3D culture, underscoring their putative role in PCa. Importantly, dual targeting of cholesterol and steroid biosynthesis with simvastatin, a commonly prescribed cholesterol synthesis inhibitor, and an inhibitor against AKR1C3 had the strongest growth inhibitory effect. CONCLUSIONS: From our results we conclude that CAFs induce an upregulation of cholesterol and steroid biosynthesis in PCa cells, driving them into AR targeted therapy resistance. Blocking both pathways with simvastatin and an AKR1C3 inhibitor may therefore be a promising approach to overcome resistances to AR targeted therapies in PCa. Video abstract.
- MeSH
- androgenní receptory metabolismus MeSH
- anotace sekvence MeSH
- benzamidy farmakologie MeSH
- biologické modely MeSH
- biosyntetické dráhy genetika MeSH
- buněčné sféroidy metabolismus patologie MeSH
- buněčný cyklus genetika MeSH
- chemorezistence účinky léků genetika MeSH
- cholesterol biosyntéza MeSH
- extracelulární matrix metabolismus MeSH
- fenotyp MeSH
- fenylthiohydantoin farmakologie MeSH
- fibroblasty asociované s nádorem metabolismus patologie MeSH
- kultivační média speciální farmakologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádory prostaty rezistentní na kastraci genetika patologie MeSH
- nádory prostaty genetika metabolismus patologie MeSH
- nitrily farmakologie MeSH
- progrese nemoci * MeSH
- proliferace buněk genetika MeSH
- regulace genové exprese u nádorů účinky léků MeSH
- senioři MeSH
- simvastatin farmakologie MeSH
- stanovení celkové genové exprese MeSH
- upregulace * MeSH
- viabilita buněk účinky léků genetika MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH