- Publikační typ
- abstrakt z konference MeSH
IFN-γ is a pleiotropic cytokine crucial for both innate and adaptive immunity, which also plays a critical role in immunological surveillance of cancer. Genetic defects or gene silencing in the IFN-γ signal transduction pathways as well as in the expression of IFN-γ-regulated genes represent frequent mechanisms by which tumour cells can escape from immune responses. Epigenetic control of the IFN-γ signalling pathway activation associated with epigenetic changes in the corresponding regulatory gene regions, such as chromatin remodelling, histone acetylation and methylation, and DNA demethylation is frequently dysregulated in tumour cells. Epigenetic silencing of the IFN-γ regulatory pathway components, as well as of the IFN-γ-regulated genes crucial for tumour cell recognition or induction of anti-tumour immune responses, has been documented in various cancer models. Expression of both IFN-γ signalling pathway components and selected IFN-γ-regulated genes can be influenced by epigenetic modifiers, namely DNA methyltransferase and histone deacetylase inhibitors. These agents thus can mimic, restore, or boost the immunomodulatory effects of IFN-γ in tumour cells, which can contribute to their anti-tumour therapeutic efficacies and justifies their potential use in combined epigenetic therapy with immunotherapeutic approaches.
- Publikační typ
- abstrakt z konference MeSH
Závěrečná zpráva o řešení grantu Interní grantové agentury MZ ČR
1 svazek : ilustrace ; 30 cm
Interactions of tumour cells with the immune system are influenced by chemotherapy with genotoxic or tumour cell senescence-inducing effects leading to increased tumour cells sensitivity to immune responses. Subsequent immunotherapy could be very effective in tumour cell elimination. Epigenetic mechanisms play a crucial role in tumour cell escape from immune responses through silencing of the immunoactive genes, as well as in senescence induction. Therefore, combination of chemoimmunotherapy with the epigenetic agents administration should increase its efficacy. This project is focused on optimization of combined chemoimmunotherapy of the minimal residual tumour disease, using genotoxic and epigenetic agents combined with immunotherapy, using preclinical murine models. Therapeutic settings based on tumour cell senescence induction followed by their elimination will be suggested. A special attention will be paid to suppressing the protumorigenic effects of the tumour senescent cells.
Interakci nádorových buněk s imunitním systémem ovlivňuje chemoterapie indukující senescenci nádorových buněk, které pak mohou být citlivější k imunitní odpovědi. K efektivní eliminaci nádorových buněk po chemoterapii buňkami imunitního systému je důležitá následná imunoterapie. Velkou roli v umlčení imunoaktivních genů v nádorových buňkách i indukci senescence hrají epigenetické mechanismy. Proto by doplnění chemoimunoterapie podáním epigenetických agens (inhibitorů DNA metyltransferáz a histondeacetyláz) mělo zvýšit její účinnost. Projekt je zaměřen na optimalizaci kombinované chemoimunoterapie zbytkové nádorové choroby pomocí genotoxických a epigenetických agens a následné imunoterapie, s využitím preklinických myších modelů. Budou navrženy terapeutické postupy, kterými bude indukována senescence nádorových buněk, které budou následně eliminovány imunitním systémem. Pozornost bude věnována potlačení protumorigenních účinků senescentních buněk.
- MeSH
- epigeneze genetická MeSH
- histondeacetylasy MeSH
- imunitní dozor MeSH
- imunoterapie MeSH
- methyltransferasy antagonisté a inhibitory MeSH
- reziduální nádor MeSH
- stárnutí buněk imunologie MeSH
- Konspekt
- Patologie. Klinická medicína
- NLK Obory
- onkologie
- NLK Publikační typ
- závěrečné zprávy o řešení grantu IGA MZ ČR
Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal stem cell disorders characterized by ineffective hematopoiesis frequently progressing into acute myeloid leukemia (AML), with emerging evidence implicating aberrant bone marrow (BM) microenvironment and inflammation-related changes. 5-azacytidine (5-AC) represents standard MDS treatment. Besides inhibiting DNA/RNA methylation, 5-AC has been shown to induce DNA damage and apoptosis in vitro. To provide insights into in vivo effects, we assessed the proinflammatory cytokines alterations during MDS progression, cytokine changes after 5-AC, and contribution of inflammatory comorbidities to the cytokine changes in MDS patients. We found that IL8, IP10/CXCL10, MCP1/CCL2 and IL27 were significantly elevated and IL12p70 decreased in BM of MDS low-risk, high-risk and AML patients compared to healthy donors. Repeated sampling of the high-risk MDS patients undergoing 5-AC therapy revealed that the levels of IL8, IL27 and MCP1 in BM plasma were progressively increasing in agreement with in vitro experiments using several cancer cell lines. Moreover, the presence of inflammatory diseases correlated with higher levels of IL8 and MCP1 in low-risk but not in high-risk MDS. Overall, all forms of MDS feature a deregulated proinflammatory cytokine landscape in the BM and such alterations are further augmented by therapy of MDS patients with 5-AC.
Cellular senescence provides a biological barrier against tumor progression, often associated with oncogene-induced replication and/or oxidative stress, cytokine production and DNA damage response (DDR), leading to persistent cell-cycle arrest. While cytokines such as tumor necrosis factor-alpha (TNFα) and interferon gamma (IFNγ) are important components of senescence-associated secretome and induce senescence in, for example, mouse pancreatic β-cancer cell model, their downstream signaling pathway(s) and links with oxidative stress and DDR are mechanistically unclear. Using human and mouse normal and cancer cell models, we now show that TNFα and IFNγ induce NADPH oxidases Nox4 and Nox1, reactive oxygen species (ROS), DDR signaling and premature senescence. Unlike mouse tumor cells that required concomitant presence of IFNγ and TNFα, short exposure to IFNγ alone was sufficient to induce Nox4, Nox1 and DDR in human cells. siRNA-mediated knockdown of Nox4 but not Nox1 decreased IFNγ-induced DDR. The expression of Nox4/Nox1 required Janus kinase (JAK)/signal transducers and activators of transcription (STAT) signaling and the effect was mediated by downstream activation of transforming growth factor-beta (TGFβ) secretion and consequent autocrine/paracrine activation of the TGFβ/Smad pathway. Furthermore, the expression of adenine nucleotide translocase 2 (ANT2) was suppressed by IFNγ contributing to elevation of ROS and DNA damage. In contrast to mouse B16 cells, inability of TC-1 cells to respond to IFNγ/TNFα by DDR and senescence correlated with the lack of TGFβ and Nox4 response, supporting the role of ROS induced by NADPH oxidases in cytokine-induced senescence. Overall, our data reveal differences between cytokine effects in mouse and human cells, and mechanistically implicate the TGFβ/SMAD pathway, via induction of NADPH oxidases and suppression of ANT2, as key mediators of IFNγ/TNFα-evoked genotoxicity and cellular senescence.
- MeSH
- enzymová indukce účinky léků MeSH
- interferon gama farmakologie MeSH
- lidé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- NADPH-oxidasy biosyntéza genetika MeSH
- oxidační stres účinky léků MeSH
- poškození DNA * MeSH
- proteiny Smad metabolismus MeSH
- reaktivní formy kyslíku metabolismus MeSH
- regulace genové exprese u nádorů MeSH
- signální transdukce účinky léků MeSH
- stárnutí buněk účinky léků MeSH
- TNF-alfa farmakologie MeSH
- transformující růstový faktor beta metabolismus MeSH
- transkripční faktory STAT metabolismus MeSH
- translokátor adeninových nukleotidů 2 metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Standard-of-care chemo- or radio-therapy can induce, besides tumor cell death, also tumor cell senescence. While senescence is considered to be a principal barrier against tumorigenesis, senescent cells can survive in the organism for protracted periods of time and they can promote tumor development. Based on this emerging concept, we hypothesized that elimination of such potentially cancer-promoting senescent cells could offer a therapeutic benefit. To assess this possibility, here we first show that tumor growth of proliferating mouse TC-1 HPV-16-associated cancer cells in syngeneic mice becomes accelerated by co-administration of TC-1 or TRAMP-C2 prostate cancer cells made senescent by pre-treatment with the anti-cancer drug docetaxel, or lethally irradiated. Phenotypic analyses of tumor-explanted cells indicated that the observed acceleration of tumor growth was attributable to a protumorigenic environment created by the co-injected senescent and proliferating cancer cells rather than to escape of the docetaxel-treated cells from senescence. Notably, accelerated tumor growth was effectively inhibited by cell immunotherapy using irradiated TC-1 cells engineered to produce interleukin IL-12. Collectively, our data document that immunotherapy, such as the IL-12 treatment, can provide an effective strategy for elimination of the detrimental effects caused by bystander senescent tumor cells in vivo.
- MeSH
- antitumorózní látky farmakologie MeSH
- bystander efekt účinky léků MeSH
- časové faktory MeSH
- cytokiny genetika metabolismus MeSH
- experimentální nádory genetika metabolismus terapie MeSH
- imunoterapie adoptivní metody MeSH
- interleukin-12 biosyntéza farmakologie MeSH
- kombinovaná terapie MeSH
- myši inbrední C57BL MeSH
- nádorové buněčné linie MeSH
- stárnutí buněk účinky léků MeSH
- taxoidy farmakologie MeSH
- tumor burden účinky léků MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Fractionated ionizing radiation combined with surgery or hormone therapy represents the first-choice treatment for medium to high-risk localized prostate carcinoma. One of the main reasons for the failure of radiotherapy in prostate cancer is radioresistance and further dissemination of surviving cells. In this study, exposure of four metastasis-derived human prostate cancer cell lines (DU145, PC-3, LNCaP and 22RV1) to clinically relevant daily fractions of ionizing radiation (35 doses of 2 Gy) resulted in generation of two radiation-surviving populations: adherent senescent-like cells expressing common senescence-associated markers and non-adherent anoikis-resistant stem cell-like cells with active Notch signaling and expression of stem cell markers CD133, Oct-4, Sox2 and Nanog. While a subset of the radiation-surviving adherent cells resumed proliferation shortly after completion of the irradiation regimen, the non-adherent cells started to proliferate only on their reattachment several weeks after the radiation-induced loss of adhesion. Like the parental non-irradiated cells, radiation-surviving re-adherent DU145 cells were tumorigenic in immunocompromised mice. The radiation-induced loss of adhesion was dependent on expression of Snail, as siRNA/shRNA-mediated knockdown of Snail prevented cell detachment. On the other hand, survival of the non-adherent cells required active Erk signaling, as chemical inhibition of Erk1/2 by a MEK-selective inhibitor or Erk1/2 knockdown resulted in anoikis-mediated death in the non-adherent cell fraction. Notably, whereas combined inhibition of Erk and PI3K-Akt signaling triggered cell death in the non-adherent cell fraction and blocked proliferation of the adherent population of the prostate cancer cells, such combined treatment had only marginal if any impact on growth of control normal human diploid cells. These results contribute to better understanding of radiation-induced stress response and heterogeneity of human metastatic prostate cancer cells, document treatment-induced plasticity and phenotypically distinct cell subsets, and suggest the way to exploit their differential sensitivity to radiosensitizing drugs in overcoming radioresistance.
- MeSH
- buněčné linie MeSH
- fluorescenční protilátková technika nepřímá MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- lidé MeSH
- MAP kinasový signální systém účinky záření MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádory prostaty patologie radioterapie MeSH
- proliferace buněk účinky záření MeSH
- průtoková cytometrie MeSH
- radioterapie MeSH
- signální transdukce účinky záření MeSH
- transkripční faktory metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Downregulation of MHC class I expression on tumour cells, a common mechanism by which tumour cells can escape from specific immune responses, can be associated with coordinated silencing of antigen-presenting machinery genes. The expression of these genes can be restored by IFNγ. In this study we documented association of DNA demethylation of selected antigen-presenting machinery genes located in the MHC genomic locus (TAP-1, TAP-2, LMP-2, LMP-7) upon IFNγ treatment with MHC class I upregulation on tumour cells in several MHC class I-deficient murine tumour cell lines (TC-1/A9, TRAMP-C2, MK16 and MC15). Our data also documented higher methylation levels in these genes in TC-1/A9 cells, as compared to their parental MHC class I-positive TC-1 cells. IFNγ-mediated DNA demethylation was relatively fast in comparison with demethylation induced by DNA methyltransferase inhibitor 5-azacytidine, and associated with increased histone H3 acetylation in the promoter regions of APM genes. Comparative transcriptome analysis in distinct MHC class I-deficient cell lines upon their treatment with either IFNγ or epigenetic agents revealed that a set of genes, significantly enriched for the antigen presentation pathway, was regulated in the same manner. Our data demonstrate that IFNγ acts as an epigenetic modifier when upregulating the expression of antigen-presenting machinery genes.
- MeSH
- down regulace MeSH
- epigeneze genetická MeSH
- fibrosarkom genetika imunologie metabolismus MeSH
- geny MHC třídy I * MeSH
- interferon gama genetika imunologie metabolismus MeSH
- metylace DNA * MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- nádorové buňky kultivované MeSH
- prezentace antigenu genetika MeSH
- regulace genové exprese u nádorů MeSH
- signální transdukce MeSH
- transfekce MeSH
- upregulace MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
