The most sensitive cell structure - a DNA molecule, is the common target of cancer therapy. DNA damage response (controlled by enzymes from the phosphatidylinositol 3-kinase-related kinases family - PIKK) presents many encouraging targets for improving both conventional cytotoxic anticancer therapy and individualized monotherapy. DNA-dependent protein kinase (DNA-PK) is a member of the PIKK superfamily and plays an important role in the detection and repair of DNA double-strand breaks via the non-homologous end-joining pathway. The ability of cancer cells to repair DNA damage is an important element determining their sensitivity to radio- or chemo-therapy. The overactivation of DNA-PK in cancers can result in resistance to anticancer therapy. The inhibition of DNA-PK is a very promising target in anticancer research. However, the specific DNA-PK inhibitors currently known are limited by poor solubility and high metabolic lability in vivo, leading to a short serum half-life. Construction of new compounds based on existing drugs is the most important strategy to improve drug efficacy, pharmacokinetic parameters and to reduce toxicity. This review will describe small molecule inhibitors and summarize their efficacy in synergizing radio- and chemotherapy in vitro.
- MeSH
- antitumorózní látky farmakologie MeSH
- fosfatidylinositol-3-kinasy MeSH
- inhibitory fosfoinositid-3-kinasy MeSH
- inhibitory proteinkinas farmakologie MeSH
- lidé MeSH
- poškození DNA MeSH
- proteinkinasa aktivovaná DNA antagonisté a inhibitory metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
In this study we assessed the effects of the frequently used chemotherapeutic agent mitoxantrone (MTX) on dental pulp stem cells (DPSCs) and compared it with the response of human dermal fibroblasts (HDFs). DPSCs are valuable source of mesenchymal stem cells which may be extremely useful in a number of clinical applications. It is evident that both normal and tumor cells are being affected during therapy and characterization of these cells under genotoxic stress contributes to the evaluation of their safety usage. In the experiment cells were exposed to doses 5-150 nmol/l MTX. Proliferation of cells was detected by Z2 counter and viability by Vi-Cell XR using Trypan blue exclusion staining. Cell cycle analysis was determinated by flow cytometry, induction of apoptosis by monitoring the activities of caspases. The expression of key proteins was detected by Western blotting. Senescence was analyzed by activity of β-galactosidase and by detection of persisting DSBs-associated γH2AX foci. Exposure of both cell types to lower concentrations of MTX resulted in premature senescence (SIPS), which was accompanied with typical morphological changes, increased activity of senescence-associated β-galactosidase, persisting DSBs-associated γH2AX foci and cell cycle arrest in G2 phase. MTX provokes the activation of p53-p21(WAF1/Cip1) pathway in both cell types and activates cell-cycle inhibitor p16(INK4a) in HDFs, but not in DPSCs. Higher concentrations of MTX induced caspase-mediated apoptosis. Conclusions: MTX induces apoptosis or SIPS in both cell types in dependency on MTX doses. Both pathways prevent the proliferation of cells with damaged DNA.
- MeSH
- antitumorózní látky farmakologie MeSH
- apoptóza účinky léků MeSH
- buněčný cyklus účinky léků MeSH
- fibroblasty účinky léků metabolismus MeSH
- inhibitory topoisomerasy II farmakologie MeSH
- kaspasy metabolismus MeSH
- kmenové buňky účinky léků metabolismus MeSH
- kultivované buňky MeSH
- kůže cytologie MeSH
- lidé MeSH
- mitoxantron farmakologie MeSH
- poškození DNA MeSH
- proliferace buněk účinky léků MeSH
- viabilita buněk účinky léků MeSH
- zubní dřeň cytologie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIM: To determine the response of dental pulp stem cells (DPSCs) to DNA-damaging cytostatic cisplatin and compare it with the response of normal human dermal fibroblasts (HDFs). METHODOLOGY: Dental pulp stem cells were exposed to 5, 10, 20 or 40 μmol L(-1) of cisplatin. The proliferation of affected cells was assessed by a Z2 Counter and viability was assessed by means of a Vi-Cell XR using Trypan blue exclusion staining. Cell cycle analysis and induction of apoptosis were performed by flow cytometry. Induction of apoptosis was determined by monitoring the activities of caspases. The expression of proteins was detected by electrophoresis and Western blotting. The descriptive statistics of the results was analyzed by Student's t-test. RESULTS: Dental pulp stem cells had a greater genotoxic stress response to cisplatin compared to HDFs. All three main Mitogen-activated protein kinases (MAPK) families - extracellular signal-regulated kinases (ERK), c-Jun-N-terminal kinase (JNK) and p38 were activated after treatment of DPSCs with cisplatin. The activation of MAPK pathways was not observed in HDFs exposed to cisplatin. The exposure of DPSCs and HDFs to cisplatin provoked an increase in p53 and p21 expression and p53 phosphorylation of serine 15. Higher concentrations of cisplatin reduced the viability of DPSCs and HDFs and induced the activation of caspases 3/7 and 9. CONCLUSION: Dental pulp stem cells had a greater genotoxic stress response to cisplatin compared to HDFs. Cisplatin in higher concentrations triggered activation of MAPK and apoptosis in DPSCs but not in HDFs.
- MeSH
- aktivace enzymů účinky léků MeSH
- apoptóza účinky léků MeSH
- buněčné kultury MeSH
- buněčný cyklus účinky léků MeSH
- cisplatina toxicita MeSH
- cytostatické látky toxicita MeSH
- ektoderm cytologie účinky léků MeSH
- extracelulárním signálem regulované MAP kinasy účinky léků MeSH
- fibroblasty účinky léků MeSH
- fosforylace MeSH
- inhibitor p21 cyklin-dependentní kinasy účinky léků MeSH
- inhibitory proteinkinas farmakologie MeSH
- JNK mitogenem aktivované proteinkinasy účinky léků MeSH
- kaspasa 3 účinky léků MeSH
- kaspasa 7 účinky léků MeSH
- kaspasa 8 účinky léků MeSH
- kaspasa 9 účinky léků MeSH
- kůže cytologie účinky léků MeSH
- lidé MeSH
- MAP kinasový signální systém účinky léků MeSH
- mezenchymální kmenové buňky účinky léků MeSH
- mitogenem aktivované proteinkinasy p38 účinky léků MeSH
- mutageny toxicita MeSH
- nádorový supresorový protein p53 účinky léků MeSH
- proliferace buněk účinky léků MeSH
- serin účinky léků MeSH
- viabilita buněk účinky léků MeSH
- zubní dřeň cytologie účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
Protein p21(Cip1/Waf1) is a cyclin-dependent kinase inhibitor, which is important in the response of cells to genotoxic stress and a major transcriptional target of p53 protein. Based on the localization, p21(Cip1/Waf1) protein executes various functions in the cell. In the nucleus p21(Cip1/Waf1) binds to and inhibits the activity of cyclin dependent kinases Cdk1 and Cdk2 and blocks the transition from G1 phase into S phase or from G2 phase into mitosis after DNA damage. This enables the repair of damaged DNA. p21(Cip1/Waf1) was also found as an important protein for the induction of replication senescence as well as stress-induced premature senescence. In the cytoplasm, p21(Cip1/Waf1) protein has an anti-apoptotic effect. It is able to bind to and inhibit caspase 3, as well as the apoptotic kinases ASK1 and JNK. The function of p21(Cip1/Waf1) in response to a DNA damage probably depends on the extent of the damage. In the case of low-level DNA damage, the expression of p21(Cip1/Waf1) is increased, it induces cell cycle arrest, and performs also anti-apoptotic activities. However, after extensive DNA damage the amount of p21(Cip1/Waf1) protein is decreased and the cell undergoes apoptosis. Dual function of p21(Cip1/Waf1) was also observed in cancerogenesis. On the one hand, p21(Cip1/Waf1) acts as a tumor suppressor; on the other hand it prevents apoptosis and acts as an oncogene. Better understanding of the role of p21(Cip1/Waf1) in various conditions would help to develop better cancer-treatment strategies.
- MeSH
- buněčné jádro metabolismus MeSH
- cytoplazma metabolismus MeSH
- inhibitor p21 cyklin-dependentní kinasy metabolismus MeSH
- lidé MeSH
- poškození DNA MeSH
- posttranslační úpravy proteinů MeSH
- subcelulární frakce metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
BACKGROUND: Dysfunction of the carnitine system in non-tumour tissue following anticancer therapy has been reported. In this setting, supplementation with carnitine derivatives might increase the general metabolic activity of normal cells so that they might better withstand the adverse effects of chemotherapy aimed at tumour cells. Here we investigated the effect of acetyl-L-carnitine (ALC) alone and in combination with the antineoplastic agent mitoxantrone (MX) in an animal cancer model. METHODS: The effects of MX and MX-ALC were assessed based on gain or loss of body weight and on local growth of a solid form of Ehrlich tumour inoculated into mice. We also performed biochemical analyses like serum activities of some enzymes signalling the functioning of the liver, aspartate aminotransferase (AST), and alanine aminotransferase (ALT). Total protein, albumin and bilirubin were also determined in serum. Under favourable conditions, the Ehrlich tumour readily forms metastases, and this is the reason why we performed histological studies of samples of both the liver and heart in order to identify changes that may have mediated the observed effect of the treatment. In addition to those studies, the survival time of treated animals against controls was also noted. RESULTS: MX monotherapy was associated with lower body weight gain, fewer metastases, smaller tumour size, and lower dissemination. ALC alone promoted survival, but had no potentiating effect on MX therapy in terms of survival. Serum biochemistry changes associated with MX-ALC treatment consisted of a significant (p < 0.05) increase in AST with MX at 6 or 9 mg·kg(-1) plus ALC 200 mg·kg(-1) and a significant (p < 0.05) reduction in total protein compared to the corresponding MX group; serum albumin and bilirubin remained unchanged. CONCLUSION: ALC in combination with MX, regardless of the dose of MX, led to higher occurrences of metastases with dissemination to the kidneys, lungs, heart, and mediastinum compared to MX treatment alone. These histological findings indicate that ALC is inappropriate to combine with MX in the treatment of a solid cancer. The protective effect of ALC in combination therapy with the cytostatic drug MX was not supported in this study by our findings that the agent did not improve the therapeutic outcomes of MX therapy.
- MeSH
- acylkarnitin terapeutické užití MeSH
- antitumorózní látky terapeutické užití MeSH
- bilirubin krev MeSH
- Ehrlichův tumor farmakoterapie patologie MeSH
- experimentální nádory jater farmakoterapie patologie MeSH
- mitoxantron terapeutické užití MeSH
- myši MeSH
- sérový albumin analýza MeSH
- tělesná hmotnost MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- Sandostatin, Somatutine PR, Cabergolin, Pegvisomant,
- MeSH
- adenom farmakoterapie chirurgie radioterapie MeSH
- agonisté dopaminu aplikace a dávkování farmakologie škodlivé účinky MeSH
- akromegalie diagnóza chirurgie radioterapie MeSH
- finanční podpora výzkumu jako téma MeSH
- insulinu podobný růstový faktor I MeSH
- kombinovaná farmakoterapie MeSH
- lidé MeSH
- oktreotid aplikace a dávkování MeSH
- růstový hormon antagonisté a inhibitory aplikace a dávkování farmakologie MeSH
- somatostatin analogy a deriváty farmakologie škodlivé účinky MeSH
- Check Tag
- lidé MeSH
