T-2 toxin is a worldwide trichothecenetoxin and can cause various toxicities.T-2 toxin is involved in G1 phase arrest in several cell lines but molecular mechanism is still not clear. In present study, we used rat pituitary GH3 cells to investigate the mechanism involved in cell cycle arrest against T-2 toxin (40 nM) for 12, 24, 36 and 48 h as compared to control cells. GH3 cells showed a considerable increase in reactive oxygen species (ROS) as well as loss in mitochondrial membrane potential (△Ym) upon exposure to the T-2 toxin. Flow cytometry showed a significant time-dependent increase in percentage of apoptotic cells and gel electrophoresis showed the hallmark of apoptosis oligonucleosomal DNA fragmentation. Additionally, T-2 toxin-induced oxidative stress and DNA damage with a time-dependent significant increased expression of p53 favors the apoptotic process by the activation of caspase-3 in T-2 toxin treated cells. Cell cycle analysis by flow cytometry revealed a time-dependent increase ofG1 cell population along with the significant time-dependent up-regulation of mRNA and protein expression of p16 and p21 and significant down-regulation of cyclin D1, CDK4, and p-RB levels further verify the G1 phase arrest in GH3 cells. Morphology of GH3 cells by TEM clearly showed the damage and dysfunction to mitochondria and the cell nucleus. These findings for the first time demonstrate that T-2 toxin induces G1 phase cell cycle arrest by the involvement of p16/Rb pathway, along with ROS mediated oxidative stress and DNA damage with p53 and caspase cascade interaction, resulting in apoptosis in GH3 cells.
- MeSH
- buněčné linie MeSH
- buněčný cyklus účinky léků fyziologie MeSH
- geny p16 účinky léků fyziologie MeSH
- hypofýza účinky léků metabolismus ultrastruktura MeSH
- krysa rodu rattus MeSH
- retinoblastomový protein biosyntéza MeSH
- signální transdukce účinky léků fyziologie MeSH
- T-2 toxin toxicita MeSH
- viabilita buněk účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Deregulation of the RB pathway is shared by most human malignancies. Components upstream of the retinoblastoma tumour suppressor (pRB), namely the INK4 family of cyclin-dependent kinase (CDK) inhibitors, the D-type cyclins, their partner kinases CDK4/CDK6, and pRB as their critical substrate, are differentially targeted in diverse types of cancer. An 'unorthodox' spectrum of defects within this cascade occurs in testicular germ cell tumours (TGCTs), including silencing of pRB transcription, overexpression of cyclin D2, and loss of p18INK4c. To improve understanding of the role of this pathway in spermatogenesis, and its subversion in TGCTs, we examined immunohistochemical expression patterns of CDK4, p16INK4a, p15INK4b, and pRB, and established an in situ assay for cyclin D-mediated phosphorylation of serine795, a phosphorylation event critical for neutralization of pRB's growth-restraining ability. pRB was expressed throughout adult spermatogenesis and was detectable in teratomas, but was absent or grossly reduced in carcinoma in situ (CIS) and most seminomas and embryonal carcinomas. Unexpectedly, we also found that pRB was absent from fetal human gonocytes, the candidate target cell for all types of TGCTs. Thus, rather than a tumorigenesis-promoting loss of pRB, the lack of pRB in TGCTs likely reflects its developmental control. Widespread expression of p15INK4b, found in normal testes, was preserved in TGCTs. In contrast, p16INK4a was lost or reduced in large subsets of TGCTs. CDK4 was expressed in normal spermatogonia, CIS, and invasive TGCTs, as was serine795-phosphorylated pRB. Our data on expression of pRB support the plausible origin of TGCTs from fetal gonocytes, and the serine795 phosphorylation demonstrates that the cyclin D-dependent kinases are active, and neutralize pRB in spermatogonia and in those TGCTs that express pRB. We hope that this study will inspire further immunohistochemical applications of phosphospecific antibodies in pathology, and examination of the RB pathway defects in relation to curability of TGCTs. Copyright 2003 John Wiley & Sons, Ltd.
- MeSH
- buněčný cyklus MeSH
- dospělí MeSH
- embryonální karcinom metabolismus MeSH
- fosforylace MeSH
- germinom * patofyziologie MeSH
- imunoenzymatické techniky MeSH
- karcinom in situ metabolismus MeSH
- kultivované buňky MeSH
- lidé MeSH
- novorozenec MeSH
- retinoblastomový protein * fyziologie MeSH
- seminom metabolismus MeSH
- teratom metabolismus MeSH
- testikulární nádory * patofyziologie MeSH
- testis metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- MeSH
- chemické techniky analytické MeSH
- látky znečišťující životní prostředí MeSH
- lidé MeSH
- monitorování životního prostředí MeSH
- referenční hodnoty metody MeSH
- stopové prvky krev moč normy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
- Geografické názvy
- Česká republika MeSH
- Slovenská republika MeSH
Cílem studie bylo testovat vliv přerušení nervus alveolaris inferiorna vybrané stopové prvky kosti dolní čelisti potkana. Materiál a metodika. Pro studii jsme použili 7–9 týdnů staré samce laboratorních potkanů kmene Wistar. Zvířata jsme rozdělili do tří skupin: kontrolní skupina (intaktní), experimentální skupina (s přerušeným nervem na levé straně) a ,,sham“ skupina (nerv jsme pouze vypreparovali, ale nepřerušili). Po 4 týdnech jsme zvířata usmrtili a extrahovali zuby (nebyly součástí studie). Kost dolní čelisti jsme rozdělili na 4 části. Ke stanovení 7 prvků v kosti jsme použili hmotnostní spektrometrii s indukčně vázaným plazmatem. Výsledky. Ze studie vyplývá, že přerušení nervu způsobilo snížení obsahu kobaltu, niklu a baria. Dále bylo příčinou vymizení rozdílu obsahů rubidia mezi levou a pravou stranou čelisti. Chirurgický přístup měl za následek změnu distribuce obsahů rubidia, molybdenu a baria v dolní čelisti a vymizení stranového rozdílu u baria v hřebeni a u niklu v meziálním místě a v hřebeni. U manganu a mědi jsme neprokázali zásadní rozdíly. Popsané změny nejspíše souvisejí s určitou přestavbou spongiózní kosti a s jejím úbytkem, jak zaznamenali jiní. Závěr. Výsledky podporují naši hypotézu, že senzitivní inervace ovlivňuje stopové prvky v kosti dolní čelisti potkana.
Objective. The purpose of the study was to test the effect of transection the inferior alveolar nerve on selected trace elements in the mandibular bone of the rat.Material and methodsWe used 7–9 weeks old males of Wistar laboratory rats for the study. The animals were divided in three groups: control (intact) group, experimental group (with the nerve transected on the left) and the sham group (the nerve was only exposed, not transected). The animals were sacrificed 4 weeks later and their teeth were extracted (not part of the study). The mandibular bone was divided in 4parts. Inductively coupled plasma mass spectrometry was used to determine 7 elements in the bone.Results. As follows from the study, nerve transection resulted in decreased contents of cobalt, nickel and barium. Furthermore, it resulted in disappearing of rubidium content differences on the left and right side of the mandible. The surgical approach itself causes changes in the distribution of rubidium, molybdenum and barium contents of the mandible and disappearance of the left and right side difference for barium in the ridge and for nickel at the mesial location and in the ridge. No sub-stantial differences were observed for manganese and copper. The described changes are probably related to acertain remodelling of the cancellous bone and its loss, as noted by others. Conclusion. The results support our hypothesis stating that sensory innervation affects trace elements in the mandibular bone.
- MeSH
- mandibula * chemie inervace MeSH
- nervus mandibularis chirurgie MeSH
- potkani Wistar MeSH
- remodelace kosti MeSH
- stopové prvky * analýza klasifikace MeSH
- výzkum MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
The clinical significance of long noncoding RNAs (lncRNAs) in colorectal cancer (CRC) remains largely unexplored. Here, we analyzed a large panel of lncRNA candidates with The Cancer Genome Atlas (TCGA) CRC dataset, and identified H19 as the most significant lncRNA associated with CRC patient survival. We further validated such association in two independent CRC cohorts. H19 silencing blocked G1-S transition, reduced cell proliferation, and inhibited cell migration. We profiled gene expression changes to gain mechanism insight of H19 function. Transcriptome data analysis revealed not only previously identified mechanisms such as Let-7 regulation by H19, but also RB1-E2F1 function and β-catenin activity as essential upstream regulators mediating H19 function. Our experimental data showed that H19 affects phosphorylation of RB1 protein by regulating gene expression of CDK4 and CCND1. We further demonstrated that reduced CDK8 expression underlies changes of β-catenin activity, and identified that H19 interacts with macroH2A, an essential regulator of CDK8 gene transcription. However, the relevance of H19-macroH2A interaction in CDK8 regulation remains to be experimentally determined. We further explored the clinical relevance of above mechanisms in clinical samples, and showed that combined analysis of H19 with its targets improved prognostic value of H19 in CRC.
- MeSH
- analýza přežití MeSH
- beta-katenin metabolismus MeSH
- cyklin-dependentní kinasa 8 genetika metabolismus MeSH
- databáze nukleových kyselin MeSH
- genové regulační sítě MeSH
- kolorektální nádory genetika metabolismus mortalita patologie MeSH
- lidé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- prognóza MeSH
- regulace genové exprese u nádorů MeSH
- retinoblastomový protein metabolismus MeSH
- RNA dlouhá nekódující genetika MeSH
- RNA interference MeSH
- signální transdukce * MeSH
- stanovení celkové genové exprese MeSH
- transkripční faktory E2F metabolismus MeSH
- transkriptom MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
