TP53 gene abnormalities represent the most important biomarker in chronic lymphocytic leukemia (CLL). Altered protein modifications could also influence p53 function, even in the wild-type protein. We assessed the impact of p53 protein phosphorylations on p53 functions as an alternative inactivation mechanism. We studied p53 phospho-profiles induced by DNA-damaging agents (fludarabine, doxorubicin) in 71 TP53-intact primary CLL samples. Doxorubicin induced two distinct phospho-profiles: profile I (heavily phosphorylated) and profile II (hypophosphorylated). Profile II samples were less capable of activating p53 target genes upon doxorubicin exposure, resembling TP53-mutant samples at the transcriptomic level, whereas standard p53 signaling was triggered in profile I. ATM locus defects were more common in profile II. The samples also differed in the basal activity of the hypoxia pathway: the highest level was detected in TP53-mutant samples, followed by profile II and profile I. Our study suggests that wild-type TP53 CLL cells with less phosphorylated p53 show TP53-mutant-like behavior after DNA damage. p53 hypophosphorylation and the related lower ability to respond to DNA damage are linked to ATM locus defects and the higher basal activity of the hypoxia pathway.
- MeSH
- ATM protein genetika metabolismus MeSH
- chronická lymfatická leukemie * genetika MeSH
- doxorubicin farmakologie MeSH
- fosforylace MeSH
- geny p53 MeSH
- hypoxie genetika MeSH
- lidé MeSH
- nádorový supresorový protein p53 * metabolismus MeSH
- poškození DNA MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Activation of p53 by small molecule MDM2 inhibitors can induce cell cycle arrest or death in p53 wildtype cancer cells. However, cancer cells exposed to hypoxia can develop resistance to other small molecules, such as chemotherapies, that activate p53. Here, we evaluated whether hypoxia could render cancer cells insensitive to two MDM2 inhibitors with different potencies, nutlin-3a and navtemadlin. Inhibitor efficacy and potency were evaluated under short-term hypoxic conditions in human and mouse cancer cells expressing different p53 genotypes (wild-type, mutant, or null). Treatment of wild-type p53 cancer cells with MDM2 inhibitors reduced cell growth by > 75% in hypoxia through activation of the p53-p21 signaling pathway; no inhibitor-induced growth reduction was observed in hypoxic mutant or null p53 cells except at very high concentrations. The concentration of inhibitors needed to induce the maximal p53 response was not significantly different in hypoxia compared to normoxia. However, inhibitor efficacy varied by species and by cell line, with stronger effects at lower concentrations observed in human cell lines than in mouse cell lines grown as 2D and 3D cultures. Together, these results indicate that MDM2 inhibitors retain efficacy in hypoxia, suggesting they could be useful for targeting acutely hypoxic cancer cells.
- MeSH
- antitumorózní látky * farmakologie MeSH
- apoptóza MeSH
- hypoxie genetika MeSH
- lidé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádorový supresorový protein p53 metabolismus MeSH
- nádory * farmakoterapie genetika MeSH
- protoonkogenní proteiny c-mdm2 metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Our aim was to study the expression of hypoxia-related proteins as a possible regulatory pathway in the contracted side tissue of relapsed clubfoot. We compared the expression of hypoxia-related proteins in the tissue of the contracted (medial) side of relapsed clubfoot, and in the tissue of the non-contracted (lateral) side of relapsed clubfoot. Tissue samples from ten patients were analyzed by immunohistochemistry and image analysis, Real-time PCR and Mass Spectrometry to evaluate the differences in protein composition and gene expression. We found a significant increase in the levels of smooth muscle actin, transforming growth factor-beta, hypoxia-inducible factor 1 alpha, lysyl oxidase, lysyl oxidase-like 2, tenascin C, matrix metalloproteinase-2, matrix metalloproteinase-9, fibronectin, collagen types III and VI, hemoglobin subunit alpha and hemoglobin subunit beta, and an overexpression of ACTA2, FN1, TGFB1, HIF1A and MMP2 genes in the contracted medial side tissue of clubfoot. In the affected tissue, we have identified an increase in the level of hypoxia-related proteins, together with an overexpression of corresponding genes. Our results suggest that the hypoxia-associated pathway is potentially a factor contributing to the etiology of clubfoot relapses, as it stimulates both angioproliferation and fibroproliferation, which are considered to be key factors in the progression and development of relapses.
- MeSH
- hemoglobin - podjednotky MeSH
- hypoxie komplikace genetika MeSH
- lidé MeSH
- matrixová metaloproteinasa 2 genetika MeSH
- pes equinovarus * genetika MeSH
- recidiva MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The reason why a few myeloma cells egress from the bone marrow (BM) into peripheral blood (PB) remains unknown. Here, we investigated molecular hallmarks of circulating tumor cells (CTCs) to identify the events leading to myeloma trafficking into the bloodstream. After using next-generation flow to isolate matched CTCs and BM tumor cells from 32 patients, we found high correlation in gene expression at single-cell and bulk levels (r ≥ 0.94, P = 10-16), with only 55 genes differentially expressed between CTCs and BM tumor cells. CTCs overexpressed genes involved in inflammation, hypoxia, or epithelial-mesenchymal transition, whereas genes related with proliferation were downregulated in CTCs. The cancer stem cell marker CD44 was overexpressed in CTCs, and its knockdown significantly reduced migration of MM cells towards SDF1-α and their adhesion to fibronectin. Approximately half (29/55) of genes differentially expressed in CTCs were prognostic in patients with newly-diagnosed myeloma (n = 553; CoMMpass). In a multivariate analysis including the R-ISS, overexpression of CENPF and LGALS1 was significantly associated with inferior survival. Altogether, these results help understanding the presence of CTCs in PB and suggest that hypoxic BM niches together with a pro-inflammatory microenvironment induce an arrest in proliferation, forcing tumor cells to circulate in PB and seek other BM niches to continue growing.
- MeSH
- epitelo-mezenchymální tranzice genetika MeSH
- exprese genu genetika MeSH
- genetická transkripce genetika MeSH
- hypoxie genetika patologie MeSH
- kostní dřeň patologie MeSH
- lidé MeSH
- mnohočetný myelom genetika patologie MeSH
- nádorové buněčné linie MeSH
- nádorové cirkulující buňky patologie MeSH
- nádorové kmenové buňky patologie MeSH
- nádorové mikroprostředí genetika MeSH
- pohyb buněk genetika MeSH
- prognóza MeSH
- proliferace buněk genetika MeSH
- zánět genetika patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Adaptation to chronic hypoxia renders the heart more tolerant to ischemia/reperfusion injury. To evaluate changes in gene expression after adaptation to chronic hypoxia by RT-qPCR, it is essential to select suitable reference genes. In a chronically hypoxic rat model, no specific reference genes have been identified in the myocardium. This study aimed to select the best reference genes in the left (LV) and right (RV) ventricles of chronically hypoxic and normoxic rats. Sprague-Dawley rats were adapted to continuous normobaric hypoxia (CNH; 12% O2 or 10% O2) for 3 weeks. The expression levels of candidate genes were assessed by RT-qPCR. The stability of genes was evaluated by NormFinder, geNorm and BestKeeper algorithms. The best five reference genes in the LV were Top1, Nupl2, Rplp1, Ywhaz, Hprt1 for the milder CNH and Top1, Ywhaz, Sdha, Nupl2, Tomm22 for the stronger CNH. In the RV, the top five genes were Hprt1, Nupl2, Gapdh, Top1, Rplp1 for the milder CNH and Tomm22, Gapdh, Hprt1, Nupl2, Top1 for the stronger CNH. This study provides validation of reference genes in LV and RV of CNH rats and shows that suitable reference genes differ in the two ventricles and depend on experimental protocol.
- MeSH
- chronická nemoc MeSH
- hypoxie genetika MeSH
- myokard metabolismus patologie MeSH
- potkani Sprague-Dawley MeSH
- referenční standardy MeSH
- regulace genové exprese * MeSH
- srdeční komory metabolismus patologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Tibetans existed in high altitude for ~25 thousand years and have evolutionary selected unique haplotypes assumed to be beneficial to hypoxic adaptation. EGLN1/PHD2 and EPAS1/HIF-2α, both crucial components of hypoxia sensing, are the two best-established loci contributing to high altitude adaptation. The co-adapted Tibetan-specific haplotype encoding for PHD2:p.[D4E/C127S] promotes increased HIF degradation under hypoxic conditions. The Tibetan-specific 200 kb EPAS1 haplotype introgressed from an archaic human population related to Denisovans which underwent evolutionary decay; however, the functional variant(s) responsible for high-altitude adaptation at EPAS1/HIF-2α have not yet been identified. Since HIF modulates the behavior of cancer cells, we hypothesized that these Tibetan selected genomic variants may modify cancer risk predisposition. Here, we ascertained the frequencies of EGLN1D4E/C127S and EGLN1C127S variants and ten EPAS1/HIF-2α variants in lung cancer patients and controls in Nepal, whose population consists of people with Indo-Aryan origin and Tibetan-related Mongoloid origin. We observed a significant association between the selected Tibetan EGLN1/PHD2 haplotype and lung cancer (p=0.0012 for D4E, p=0.0002 for C127S), corresponding to a two-fold increase in lung cancer risk. We also observed a two-fold or greater increased risk for two of the ten EPAS1/HIF-2α variants, although the association was not significant after correcting for multiple comparisons (p=0.12). Although these data cannot address the role of these genetic variants on lung cancer initiation or progression, we conclude that some selected Tibetan variants are strongly associated with a modified risk of lung cancer.
- MeSH
- aklimatizace MeSH
- faktor 1 indukovatelný hypoxií - podjednotka alfa genetika metabolismus MeSH
- hypoxie genetika metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- nádory plic genetika metabolismus MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Tibet MeSH
- MeSH
- biologické markery MeSH
- dospělí MeSH
- exprese genu * MeSH
- faktor 1 indukovatelný hypoxií - podjednotka alfa genetika metabolismus MeSH
- hodnocení rizik MeSH
- hypoxie genetika metabolismus MeSH
- incidence MeSH
- lidé středního věku MeSH
- lidé MeSH
- nádorový supresorový protein VHL genetika MeSH
- následné studie MeSH
- polycytemie komplikace genetika metabolismus MeSH
- prognóza MeSH
- proporcionální rizikové modely MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- studie případů a kontrol MeSH
- thrombospondin 1 genetika MeSH
- trombóza krev diagnóza epidemiologie etiologie MeSH
- zárodečné mutace MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- dopisy MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Continuous normobaric hypoxia (CNH) renders the heart more tolerant to acute ischemia/reperfusion injury. Protein kinase C (PKC) is an important component of the protective signaling pathway, but the contribution of individual PKC isoforms under different hypoxic conditions is poorly understood. The aim of this study was to analyze the expression of PKCepsilon after the adaptation to CNH and to clarify its role in increased cardiac ischemic tolerance with the use of PKCepsilon inhibitory peptide KP-1633. Adult male Wistar rats were exposed to CNH (10 % O(2), 3 weeks) or kept under normoxic conditions. The protein level of PKCepsilon and its phosphorylated form was analyzed by Western blot in homogenate, cytosolic and particulate fractions; the expression of PKCepsilon mRNA was measured by RT-PCR. The effect of KP-1633 on cell viability and lactate dehydrogenase (LDH) release was analyzed after 25-min metabolic inhibition followed by 30-min re-energization in freshly isolated left ventricular myocytes. Adaptation to CNH increased myocardial PKCepsilon at protein and mRNA levels. The application of KP-1633 blunted the hypoxia-induced salutary effects on cell viability and LDH release, while control peptide KP-1723 had no effect. This study indicates that PKCepsilon is involved in the cardioprotective mechanism induced by CNH.
- MeSH
- fyziologická adaptace genetika MeSH
- hypoxie enzymologie genetika patofyziologie MeSH
- inhibitory proteinkinas farmakologie MeSH
- kardiomyocyty účinky léků metabolismus MeSH
- krysa rodu rattus MeSH
- L-laktátdehydrogenasa metabolismus MeSH
- messenger RNA biosyntéza genetika MeSH
- potkani Wistar MeSH
- proteinkinasa C-epsilon antagonisté a inhibitory biosyntéza genetika MeSH
- reperfuzní poškození myokardu enzymologie genetika MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cardiovascular defects are one of the most common congenital defects associated with maternal diabetes. Based on whole embryo gene expression microarray analysis, 11 genes were chosen for temporal expression analysis of diabetes-exposed hearts. The majority of the selected genes were deregulated in diabetes-exposed hearts compared to our controls at E13.5, E14.5, and E18.5. We showed increased hypoxia and HIF-1α protein levels in diabetes-exposed hearts at E10.5, which is a critical time point for the induction of developmental defects associated with diabetic embryopathy. Additionally, we found increased cardiac Vegfa levels that might trigger developmental abnormalities associated with diabetic embryopathy. Our results show that maternal diabetes affects the temporal expression pattern of gene encoding molecules involved in heart development and tissue remodelling and that these molecules might affect heart maturation processes and thus, the final outcome of diabetic pregnancies.
- MeSH
- embryo savčí MeSH
- experimentální diabetes mellitus genetika metabolismus MeSH
- faktor 1 indukovatelný hypoxií - podjednotka alfa metabolismus MeSH
- hypoxie genetika metabolismus MeSH
- inbrední kmeny myší MeSH
- messenger RNA metabolismus MeSH
- myokard metabolismus MeSH
- srdce embryologie MeSH
- stanovení celkové genové exprese MeSH
- těhotenství při diabetu genetika metabolismus MeSH
- těhotenství MeSH
- vaskulární endoteliální růstový faktor A genetika MeSH
- vývojová regulace genové exprese * MeSH
- zvířata MeSH
- Check Tag
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Although physiological responses to chronic hypoxia, including pulmonary hypertension and right ventricular hypertrophy, have been well described, the molecular mechanisms involved in cardiopulmonary adaptations are still not fully understood. We hypothesize that adaptive responses to chronic hypoxia are the result of altered transcriptional regulations in the right and left ventricles. Here we report results from the gene expression profiling of adaptive responses in a chronically hypoxic heart. Of 11 analyzed candidate genes, the expression of seven and four genes, respectively, was significantly altered in the right ventricle of hypoxic male and female mice. In the transcriptional profile of the left ventricle, we identified a single expression change in hypoxic males (Vegfa gene). To directly test the role of HIF1, we analyzed the expression profile in Hif1a partially deficient mice exposed to moderate hypoxia. Our data showed that Hif1a partial deficiency significantly altered transcriptional profiles of analyzed genes in hypoxic hearts. The expression changes were only detected in two genes in the right ventricle of Hif1a(+/-) males and in one gene in the right ventricle of Hif1a(+/-) females. First, our results suggest that hypoxia mainly affects adaptive expression profiles in the right ventricle and that each ventricle can respond independently. Second, our findings indicate that HIF1a plays an important role in adaptive cardiopulmonary responses and the dysfunction of HIF1 pathways considerably affects transcriptional regulation in the heart. Third, our data reveal significant differences between males and females in cardiac adaptive responses to hypoxia and indicate the necessity of optimizing diagnostic and therapeutic procedures in clinical practice, with respect to sex.
- MeSH
- časové faktory MeSH
- chronická nemoc MeSH
- faktor 1 indukovatelný hypoxií - podjednotka alfa nedostatek genetika metabolismus MeSH
- fyziologická adaptace MeSH
- genetická transkripce MeSH
- hematokrit MeSH
- hypoxie genetika metabolismus patofyziologie MeSH
- kardiomegalie genetika metabolismus patofyziologie MeSH
- krevní tlak MeSH
- messenger RNA metabolismus MeSH
- modely nemocí na zvířatech MeSH
- myši inbrední C57BL MeSH
- myši knockoutované MeSH
- myši MeSH
- plicní hypertenze genetika metabolismus patofyziologie MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- regulace genové exprese MeSH
- sexuální faktory MeSH
- srdce - funkce komor genetika MeSH
- srdeční komory metabolismus patofyziologie MeSH
- stanovení celkové genové exprese metody MeSH
- tělesná hmotnost MeSH
- vaskulární endoteliální růstový faktor A genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH