In cancer, the activating transcription factor 2 (ATF2) has pleiotropic functions in cellular responses to growth stimuli, damage, or inflammation. Due to only limited studies, the significance of ATF2 in colorectal cancer (CRC) is not well understood. We report that low ATF2 levels correlated with worse prognosis and tumor aggressiveness in CRC patients. NanoString gene expression and ChIP analysis confirmed trophoblast cell surface antigen 2 (TROP2) as a novel inhibitory ATF2 target gene. This inverse correlation was further observed in primary human tumor tissues. Immunostainings revealed that high intratumoral heterogeneity for ATF2 and TROP2 expression was sustained also in liver metastasis. Mechanistically, our in vitro data of CRISPR/Cas9-generated ATF2 knockout (KO) clones revealed that high TROP2 levels were critical for cell de-adhesion and increased cell migration without triggering EMT. TROP2 was enriched in filopodia and displaced Paxillin from adherens junctions. In vivo imaging, micro-computer tomography, and immunostainings verified that an ATF2KO/TROP2high status triggered tumor invasiveness in in vivo mouse and chicken xenograft models. In silico analysis provided direct support that ATF2low/TROP2high expression status defined high-risk CRC patients. Finally, our data demonstrate that ATF2 acts as a tumor suppressor by inhibiting the cancer driver TROP2. Therapeutic TROP2 targeting might prevent particularly the first steps in metastasis, i.e., the de-adhesion and invasion of colon cancer cells.

• Klíčová slova
• CAM model, De-adhesion, EMT, Intratumoral heterogeneity, Liver metastasis, Migration,
• MeSH
• antigeny nádorové * genetika   metabolismus   MeSH
• kolorektální nádory * genetika   patologie   MeSH
• lidé MeSH
• molekuly buněčné adheze genetika   metabolismus   MeSH
• myši MeSH
• nádorové buněčné linie metabolismus   MeSH
• proliferace buněk MeSH
• transkripční faktor ATF2 * genetika   metabolismus   MeSH
• upregulace MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny nádorové * MeSH
• ATF2 protein, human MeSH Prohlížeč
• molekuly buněčné adheze MeSH
• TACSTD2 protein, human MeSH Prohlížeč
• transkripční faktor ATF2 * MeSH

Recirculation of chronic lymphocytic leukemia (CLL) cells between the peripheral blood and lymphoid niches plays a critical role in disease pathophysiology, and inhibiting this process is one of the major mechanisms of action for B-cell receptor (BCR) inhibitors such as ibrutinib and idelalisib. Migration is a complex process guided by chemokine receptors and integrins. However, it remains largely unknown how CLL cells integrate multiple migratory signals while balancing survival in the peripheral blood and the decision to return to immune niches. Our study provided evidence that CXCR4/CD5 intraclonal subpopulations can be used to study the regulation of migration of CLL cells. We performed RNA profiling of CXCR4dimCD5bright vs CXCR4brightCD5dim CLL cells and identified differential expression of dozens of molecules with a putative function in cell migration. GRB2-associated binding protein 1 (GAB1) positively regulated CLL cell homing capacity of CXCR4brightCD5dim cells. Gradual GAB1 accumulation in CLL cells outside immune niches was mediated by FoxO1-induced transcriptional GAB1 activation. Upregulation of GAB1 also played an important role in maintaining basal phosphatidylinositol 3-kinase (PI3K) activity and the "tonic" AKT phosphorylation required to sustain the survival of resting CLL B cells. This finding is important during ibrutinib therapy, because CLL cells induce the FoxO1-GAB1-pAKT axis, which represents an adaptation mechanism to the inability to home to immune niches. We have demonstrated that GAB1 can be targeted therapeutically by novel GAB1 inhibitors, alone or in combination with BTK inhibition. GAB1 inhibitors induce CLL cell apoptosis, impair cell migration, inhibit tonic or BCR-induced AKT phosphorylation, and block compensatory AKT activity during ibrutinib therapy.

• MeSH
• adaptorové proteiny signální transdukční biosyntéza   MeSH
• adenin analogy a deriváty   farmakologie   MeSH
• chronická lymfatická leukemie farmakoterapie   metabolismus   patologie   MeSH
• forkhead box protein O1 metabolismus   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• piperidiny farmakologie   MeSH
• pohyb buněk * MeSH
• protoonkogenní proteiny c-akt metabolismus   MeSH
• regulace genové exprese u leukemie * MeSH
• signální transdukce * MeSH
• upregulace * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• adenin MeSH
• forkhead box protein O1 MeSH
• FOXO1 protein, human MeSH Prohlížeč
• GAB1 protein, human MeSH Prohlížeč
• ibrutinib MeSH Prohlížeč
• piperidiny MeSH
• protoonkogenní proteiny c-akt MeSH

Introduction of small-molecule inhibitors of B-cell receptor signaling and BCL2 protein significantly improves therapeutic options in chronic lymphocytic leukemia. However, some patients suffer from adverse effects mandating treatment discontinuation, and cases with TP53 defects more frequently experience early progression of the disease. Development of alternative therapeutic approaches is, therefore, of critical importance. Here we report details of the anti-chronic lymphocytic leukemia single-agent activity of MU380, our recently identified potent, selective, and metabolically robust inhibitor of checkpoint kinase 1. We also describe a newly developed enantioselective synthesis of MU380, which allows preparation of gram quantities of the substance. Checkpoint kinase 1 is a master regulator of replication operating primarily in intra-S and G2/M cell cycle checkpoints. Initially tested in leukemia and lymphoma cell lines, MU380 significantly potentiated efficacy of gemcitabine, a clinically used inducer of replication stress. Moreover, MU380 manifested substantial single-agent activity in both TP53-wild type and TP53-mutated leukemia and lymphoma cell lines. In chronic lymphocytic leukemia-derived cell lines MEC-1, MEC-2 (both TP53-mut), and OSU-CLL (TP53-wt) the inhibitor impaired cell cycle progression and induced apoptosis. In primary clinical samples, MU380 used as a single-agent noticeably reduced the viability of unstimulated chronic lymphocytic leukemia cells as well as those induced to proliferate by anti-CD40/IL-4 stimuli. In both cases, effects were comparable in samples harboring p53 pathway dysfunction (TP53 mutations or ATM mutations) and TP53-wt/ATM-wt cells. Lastly, MU380 also exhibited significant in vivo activity in a xenotransplant mouse model (immunodeficient strain NOD-scid IL2Rγnull ) where it efficiently suppressed growth of subcutaneous tumors generated from MEC-1 cells.

• MeSH
• antimetabolity antitumorózní farmakologie   MeSH
• apoptóza MeSH
• buněčný cyklus MeSH
• checkpoint kinasa 1 antagonisté a inhibitory   MeSH
• chemorezistence účinky léků   MeSH
• chronická lymfatická leukemie farmakoterapie   genetika   patologie   MeSH
• deoxycytidin analogy a deriváty   farmakologie   MeSH
• gemcitabin MeSH
• inhibitory proteinkinas farmakologie   MeSH
• lidé MeSH
• mutace * MeSH
• myši inbrední NOD MeSH
• myši SCID MeSH
• myši MeSH
• nádorové biomarkery genetika   MeSH
• nádorové buňky kultivované MeSH
• nádorový supresorový protein p53 genetika   MeSH
• piperidiny farmakologie   MeSH
• proliferace buněk MeSH
• pyrazoly farmakologie   MeSH
• pyrimidiny farmakologie   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• synergismus léků * MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antimetabolity antitumorózní MeSH
• checkpoint kinasa 1 MeSH
• CHEK1 protein, human MeSH Prohlížeč
• deoxycytidin MeSH
• gemcitabin MeSH
• inhibitory proteinkinas MeSH
• MK-8776 MeSH Prohlížeč
• MU380 MeSH Prohlížeč
• nádorové biomarkery MeSH
• nádorový supresorový protein p53 MeSH
• piperidiny MeSH
• pyrazoly MeSH
• pyrimidiny MeSH
• TP53 protein, human MeSH Prohlížeč

G-quadruplex ligands exert their antiproliferative effects through telomere-dependent and telomere-independent mechanisms, but the inter-relationships among autophagy, cell growth arrest and cell death induced by these ligands remain largely unexplored. Here, we demonstrate that the G-quadruplex ligand 20A causes growth arrest of cancer cells in culture and in a HeLa cell xenografted mouse model. This response is associated with the induction of senescence and apoptosis. Transcriptomic analysis of 20A treated cells reveals a significant functional enrichment of biological pathways related to growth arrest, DNA damage response and the lysosomal pathway. 20A elicits global DNA damage but not telomeric damage and activates the ATM and autophagy pathways. Loss of ATM following 20A treatment inhibits both autophagy and senescence and sensitizes cells to death. Moreover, disruption of autophagy by deletion of two essential autophagy genes ATG5 and ATG7 leads to failure of CHK1 activation by 20A and subsequently increased cell death. Our results, therefore, identify the activation of ATM by 20A as a critical player in the balance between senescence and apoptosis and autophagy as one of the key mediators of such regulation. Thus, targeting the ATM/autophagy pathway might be a promising strategy to achieve the maximal anticancer effect of this compound.

• MeSH
• apoptóza účinky léků   genetika   MeSH
• ATM protein * antagonisté a inhibitory   metabolismus   MeSH
• autofagie účinky léků   genetika   MeSH
• buňky A549 MeSH
• G-kvadruplexy * MeSH
• HeLa buňky MeSH
• lidé MeSH
• ligandy MeSH
• myši inbrední NOD MeSH
• myši knockoutované MeSH
• myši SCID MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory genetika   patologie   MeSH
• poškození DNA účinky léků   MeSH
• signální transdukce účinky léků   genetika   MeSH
• stárnutí buněk účinky léků   genetika   MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ATM protein, human MeSH Prohlížeč
• ATM protein * MeSH
• ligandy MeSH

Patient-derived xenografts (PDXs) have emerged as an important platform to elucidate new treatments and biomarkers in oncology. PDX models are used to address clinically relevant questions, including the contribution of tumour heterogeneity to therapeutic responsiveness, the patterns of cancer evolutionary dynamics during tumour progression and under drug pressure, and the mechanisms of resistance to treatment. The ability of PDX models to predict clinical outcomes is being improved through mouse humanization strategies and the implementation of co-clinical trials, within which patients and PDXs reciprocally inform therapeutic decisions. This Opinion article discusses aspects of PDX modelling that are relevant to these questions and highlights the merits of shared PDX resources to advance cancer medicine from the perspective of EurOPDX, an international initiative devoted to PDX-based research.

• MeSH
• chemorezistence MeSH
• imunoterapie MeSH
• individualizovaná medicína * MeSH
• klinické zkoušky jako téma MeSH
• lidé MeSH
• metastázy nádorů MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• nádorové biomarkery analýza   MeSH
• nádorové kmenové buňky fyziologie   MeSH
• nádory patologie   terapie   MeSH
• xenogenní modely - testy antitumorózní aktivity * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• nádorové biomarkery MeSH