Supplementary Figures S1-S2; Supplementary Materials and Methods; Supplementary Tables S1-S2.
Supplementary Figure 1 from Transcriptional Repression of <i>SKP2</i> Is Impaired in <i>MYCN</i>-Amplified Neuroblastoma
Supplementary Figure 3 from Transcriptional Repression of <i>SKP2</i> Is Impaired in <i>MYCN</i>-Amplified Neuroblastoma
Supplementary Table 1 from CAMTA1, a 1p36 Tumor Suppressor Candidate, Inhibits Growth and Activates Differentiation Programs in Neuroblastoma Cells
Supplementary Figure 3 from Coordinated Expression of Stathmin Family Members by Far Upstream Sequence Element-Binding Protein-1 Increases Motility in Non–Small Cell Lung Cancer
Supplementary Figure Legends 1-5 from Coordinated Expression of Stathmin Family Members by Far Upstream Sequence Element-Binding Protein-1 Increases Motility in Non–Small Cell Lung Cancer
Supplementary Table 1 from Transcriptional Repression of <i>SKP2</i> Is Impaired in <i>MYCN</i>-Amplified Neuroblastoma
The effect of sperm molecular defects on fertilization and pregnancy outcome after assisted reproductive therapy (ART) is widely documented by both research and clinical societies. Sperm DNA fragmentation and abnormal chromatin condensation represent critical causes of male infertility. Advanced androgenic techniques for accurately identifying molecular defects help in selecting an appropriate treatment strategy. Additionally, specific markers of apoptosis are increasingly important in predicting male infertility. The ability of flow cytometry to estimate the quantity of sperm with DNA fragmentation or damage and multifactor measurements in immotile sperm have made this developed technique essential in fertility centers. The study is aimed at assessing the level of DNA fragmentation and apoptosis by measuring flow cytometry using new techniques. Flow cytometry analysis revealed a varying degree of DNA damage. It was able to quantify the degree of impairment even in samples with minimal DNA fragmentation. DNA damage was observed even in samples that were considered normal with a routine semen analysis. Flow cytometry was sensitive to changes in sperm apoptosis. Elevated p53 activity levels were associated with high DNA fragmentation. Meanwhile, B-cell lymphoma 2 (Bcl-2) activities showed a different pattern. In conclusion, flow cytometry for sperm DNA fragmentation and markers of apoptosis can be a valuable tool in assisted reproductive centers.
Personalized anti-cancer medicine is boosted by the recent development of molecular diagnostics and molecularly targeted drugs requiring rapid and efficient ligation routes. Here, we present a novel approach to synthetize a conjugate able to act simultaneously as an imaging and as a chemotherapeutic agent by coupling functional peptides employing solid phase peptide synthesis technologies. Development and the first synthesis of a fluorescent dye with similarity in the polymethine part of the Cy7 molecule whose indolenine-N residues were substituted with a propylene linker are described. Methylating agent temozolomide is functionalized with a tetrazine as a diene component whereas Cy7-cell penetrating peptide conjugate acts as a dienophilic reaction partner for the inverse Diels-Alder click chemistry-mediated ligation route yielding a theranostic conjugate, 3-mercapto-propionic-cyclohexenyl-Cy7-bis-temozolomide-bromide-cell penetrating peptide. Synthesis route described here may facilitate targeted delivery of the therapeutic compound to achieve sufficient local concentrations at the target site or tissue. Its versatility allows a choice of adequate imaging tags applicable in e.g. PET, SPECT, CT, near-infrared imaging, and therapeutic substances including cytotoxic agents. Imaging tags and therapeutics may be simultaneously bound to the conjugate applying click chemistry. Theranostic compound presented here offers a solid basis for a further improvement of cancer management in a precise, patient-specific manner.
Transcription factors integrate a variety of oncogenic input information, facilitate tumour growth and cell dissemination, and therefore represent promising therapeutic target structures. Because over‐expression of DNA ‐interacting far upstream element binding protein ( FBP ) supports non‐small cell lung cancer ( NSCLC ) migration, we asked whether its repressor, FBP ‐interacting repressor ( FIR ) is functionally inactivated and how FIR might affect NSCLC cell biology. Different FIR splice variants were highly expressed in the majority of NSCLCs , with the highest levels in tumours carrying genomic gains of chromosome 8q24.3, which contained the FIR gene locus. Nuclear FIR expression was significantly enriched at the invasion front of primary NSCLCs , but this did not correlate with tumour cell proliferation. FIR accumulation was associated with worse patient survival and tumour recurrence; in addition, FIR over‐expression significantly correlated with lymph node metastasis in squamous cell carcinomas ( SCCs ). In vitro , we applied newly developed methods and modelling approaches for the quantitative and time‐resolved description of the pro‐migratory and pro‐invasive capacities of SCC cells. siRNA ‐mediated silencing of all FIR variants significantly reduced the speed and directional movement of tumour cells in all phases of migration. Furthermore, sprouting efficiency and single cell invasiveness were diminished following FIR inhibition. Interestingly, the silencing of FIR isoforms lacking exon 2 ( FIR Δexon2 ) alone was sufficient to reduce lateral migration and invasion. In summary, by using scale‐spanning data derived from primary human tissues, quantitative cellular analyses and mathematical modelling, we have demonstrated that concomitant over‐expression of FIR and its splice variants drives NSCLC migration and dissemination. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
BACKGROUND:Minimal improvements in treatment or survival of patients with osteosarcoma have been achieved during the last three decades. Especially in the case of incomplete tumor resection, prognosis remains poor. Heavy ion radiotherapy (HIT) and modern anticancer drugs like histone deacetylase inhibitors (HDACi) have shown promising effects in osteosarcoma in vitro. In this study, we tested the effect of HIT and the combination of HIT and the HDACi suberoylanilide hydroxamic acid (SAHA) in a xenograft mouse model.METHODS:Osteosarcoma xenografts were established by subcutaneous injection of KHOS-24OS cells and treated with either vehicle (DMSO), SAHA, HIT or HIT and SAHA. Tumor growth was determined and tumor necrosis, proliferation rate, apoptotic rate as well as vessel density were evaluated.RESULTS:Here, we show that the combination of HIT and SAHA induced a significant delay of tumor growth through increased rate of apoptosis, increased expression of p53 and p21(Waf1/Cip1), inhibition of proliferation and angiogenesis compared to tumors treated with HIT only.CONCLUSION:HIT and in particular the combination of HIT and histone deacetylase inhibition is a promising treatment strategy in OS and may be tested in clinical trials.
The HMGB1 protein has multiple functions in tumor biology and can act both as a transcription factor and as a cytokine. HMGB1 is released during cell death, and in our previous studies we demonstrated that HMGB1 induces a distinct, necrosis-like cell death in glioblastoma. In epithelial malignant tumors such as colorectal cancer (CRC), the HMGB1-dependent effects show cross-talk with apoptotic signal transduction. Treatment of CRC cells with low concentrations of recombinant HMGB1 results in dose-dependent cytotoxicity which is morphologically characterized by the formation of giant mitochondria and does not share features of apoptosis. HMGB1-triggered cell death is associated with intracellular ROS release, and overexpression of Bcl-2 blocks both the increase of ROS as well as HMGB1-dependent cell death. Importantly, treatment with recombinant HMGB1 or overexpression of endogenous HMGB1 strongly sensitizes CRC cells to the cytotoxic activity of the pro-apoptotic death ligand TRAIL as well as the small molecule Bcl-2 family inhibitor ABT‑737. Moreover, treatment of CRC cells with TRAIL or ABT‑737 induces a release of endogenous HMGB1 into the extracellular space, and preincubation with glycyrrhizin, an HMGB1 inhibitor, significantly inhibits induction of cell death by TRAIL and ABT‑737, suggesting that HMGB1 functionally contributes to the execution of cell death triggered by pro-apoptotic agents. Finally, we investigated the expression of HMGB1 in human CRC tumor samples and found that loss of HMGB1 expression is associated with a more aggressive phenotype and a more advanced stage of disease in patients with CRC. Altogether, our findings demonstrate a functional link between cytotoxic signaling cascades triggered by HMGB1 and pro-apoptotic agents leading to an HMGB1-dependent sensitization to CRC cell death. Thus, a further evaluation of recombinant HMGB1 as part of an experimental combination treatment of CRC seems warranted.
Segmental genomic copy number alterations, such as loss of 11q or 3p and gain of 17q, are well established markers of poor outcome in neuroblastoma, and have been suggested to comprise tumor suppressor genes or oncogenes, respectively. The gene forkhead box P1 (FOXP1) maps to chromosome 3p14.1, a tumor suppressor locus deleted in many human cancers including neuroblastoma. FoxP1 belongs to a family of winged-helix transcription factors that are involved in processes of cellular proliferation, differentiation and neoplastic transformation.
The mammalian timeless (TIM) protein interacts with proteins of the endogenous clock and essentially contributes to the circadian rhythm. In addition, TIM is involved in maintenance of chromosome integrity, growth control and development. Thus, we hypothesized that TIM may exert a potential protumorigenic function in human hepatocarcinogenesis. TIM was overexpressed in a subset of human HCCs both at the mRNA and the protein level. siRNA-mediated knockdown of TIM reduced cell viability due to the induction of apoptosis and G2 arrest. The latter was mediated via CHEK2 phosphorylation. In addition, siRNA-treated cells showed a significantly reduced migratory capacity and reduced expression levels of various proteins. Mechanistically, TIM directly interacts with the eukaryotic elongation factor 1A2 (EEF1A2), which binds to actin filaments to promote tumor cell migration. siRNA-mediated knockdown of TIM reduced EEF1A2 protein levels thereby affecting ribosomal protein biosynthesis. Thus, overexPression of TIM exerts oncogenic function in human HCCs, which is mediated via CHEK2 and EEF1A2.
Proteins of the karyopherin superfamily including importins and exportins represent an essential part of the nucleocytoplasmic transport machinery. However, the functional relevance and regulation of karyopherins in hepatocellular carcinoma (HCC) is poorly understood. Here we identified cellular apoptosis susceptibility (CAS, exportin-2) and its transport substrate importin-α1 (imp-α1) among significantly up-regulated transport factor genes in HCC. Disruption of the CAS/imp-α1 transport cycle by RNA i in HCC cell lines resulted in decreased tumor cell growth and increased apoptosis. The apoptotic phenotype upon CAS depletion could be recapitulated by direct knockdown of the X-linked inhibitor of apoptosis (XIAP) and partially reverted by XIAP overexpression. In addition, XIAP and CAS mRNA expression levels were correlated in HCC patient samples ( r = 0.463; P < 0.01), supporting the in vivo relevance of our findings. Furthermore, quantitative mass spectrometry analyses of murine HCC samples (p53−/− versus p53+/+) indicated higher protein expression of CAS and imp-α1 in p53−/− tumors. Consistent with a role of p53 in regulating the CAS/imp-α1 transport cycle, we observed that both transport factors were repressed upon p53 induction in a p21-dependent manner. Conclusion : The CAS/imp-α1 transport cycle is linked to XIAP and is required to maintain tumor cell survival in HCC. Moreover, CAS and imp-α1 are targets of p53-mediated repression, which represents a novel aspect of p53's ability to control tumor cell growth in hepatocarcinogenesis. (Hepatology 2014;60:884–895)
Uncontrolled cell cycle entry, resulting from deregulated CDK-RB1-E2F pathway activity, is a crucial determinant of neuroblastoma cell malignancy. Here we identify neuroblastoma-suppressive functions of the p19-INK4d CDK inhibitor and uncover mechanisms of its repression in high-risk neuroblastomas. Reduced p19-INK4d expression was associated with poor event-free and overall survival and neuroblastoma risk factors including amplified MYCN in a set of 478 primary neuroblastomas. High MYCN expression repressed p19-INK4d mRNA and protein levels in different neuroblastoma cell models with conditional MYCN expression. MassARRAY and 450K methylation analyses of 105 primary neuroblastomas uncovered a differentially methylated region within p19-INK4d. Hypermethylation of this region was associated with reduced p19-INK4d expression. In accordance, p19-INK4d expression was activated upon treatment with the demethylating agent, 2'-deoxy-5-azacytidine, in neuroblastoma cell lines. Ectopic p19-INK4d expression decreased viability, clonogenicity and the capacity for anchorage-independent growth of neuroblastoma cells, and shifted the cell cycle towards the G1/0 phase. p19-INK4d also induced neurite-like processes and markers of neuronal differentiation. Moreover, neuroblastoma cell differentiation, induced by all-trans retinoic acid or NGF-NTRK1-signaling, activated p19-INK4d expression. Our findings pinpoint p19-INK4d as a neuroblastoma suppressor and provide evidence for MYCN-mediated repression and for epigenetic silencing of p19-INK4d by DNA hypermethylation in high-risk neuroblastomas.
Cutaneous regeneration utilizes paracrine feedback mechanisms to fine-tune the regulation of epidermal keratinocyte proliferation and migration. However, it is unknown how fibroblast-derived hepatocyte growth factor (HGF) affects these mutually exclusive processes in distinct cell populations. We here show that HGF stimulates the expression and phosphorylation of the microtubule-destabilizing factor stathmin in primary human keratinocytes. Quantitative single cell- and cell population-based analyses revealed that basal stathmin levels are important for the migratory ability of keratinocytes in vitro; however, its expression is moderately induced in the migration tongue of mouse skin or organotypic multi-layered keratinocyte 3D cultures after full-thickness wounding. In contrast, clearly elevated stathmin expression is detectable in hyperproliferative epidermal areas. In vitro, stathmin silencing significantly reduced keratinocyte proliferation. Automated quantitative and time-resolved analyses in organotypic cocultures demonstrated a high correlation between Stathmin/phospho-Stathmin and Ki67 positivity in epidermal regions with proliferative activity. Thus, activation of stathmin may stimulate keratinocyte proliferation, while basal stathmin levels are sufficient for keratinocyte migration during cutaneous regeneration.
There is emerging evidence that malignant progression can involve deregulated expression and function of nuclear transport factors. As an important member of the nucleo-cytoplasmic transport machinery the karyopherin Cellular Apoptosis Susceptibility (CAS) re-shuttles importin-α from the nucleus to the cytoplasm. As indicated by its name CAS was reported to have proapoptotic functions under stressed conditions. Surprisingly, we found that under unstressed conditions CAS knockdown in hepatoma cell lines leads to an increase of apoptosis and to attenuated cell growth, proliferation, migration, and invasion. Consistent with these findings overexpression of CAS was detected on mRNA and protein level in the majority of hepatocellular carcinoma (HCC) tissue samples analyzed. To identity potential downstream targets of CAS we performed gene expression arrays indicating that CAS depletion is followed by downregulation of the X-linked inhibitor of apoptosis (XIAP). Furthermore, direct knockdown of XIAP partially phenocopied the effects observed upon CAS ablation. Finally, we found that CAS is a repression target of p53.
Angiogenesis plays an important role in cancer progression and involves activation of multiple signaling cascades. This study investigated the relationships between microvessel density, expression of VEGF and VEGFR1 (FLT1), and gastric cancer (GC) recurrence. Twenty-nine surgically treated GC cases with similar initial clinical presentation were selected for the study; 11 of these cases recurred within 3 years, while the remaining 18 did not. Microvessel density correlated with VEGF mRNA content, but neither of these parameters was associated with the disease outcome. When tumors were ranked according to the level of expression of angiogenic molecules, 9 out of 10 cases with the highest VEGFR1 expression belonged to the recurrence group, while none of the 10 GC with the lowest content of VEGFR1 mRNA had the disease relapse (p = 0.000). VEGFR1 expression did not show even a trend to correlation with the level of cancer tissue vascularization. Immunofluorescent staining by anti-VEGFR1 antibody revealed VEGFR1 expression in tumor cells but not in other cell types. Our data provide indirect support to the evidence for a non-angiogenic contribution of VEGFR1 in cancer pathogenesis.