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The entry of mammalian cells into the DNA synthesis phase (S phase) represents a key event in cell division1. According to current models of the cell cycle, the kinase CDC7 constitutes an essential and rate-limiting trigger of DNA replication, acting together with the cyclin-dependent kinase CDK2. Here we show that CDC7 is dispensable for cell division of many different cell types, as determined using chemical genetic systems that enable acute shutdown of CDC7 in cultured cells and in live mice. We demonstrate that another cell cycle kinase, CDK1, is also active during G1/S transition both in cycling cells and in cells exiting quiescence. We show that CDC7 and CDK1 perform functionally redundant roles during G1/S transition, and at least one of these kinases must be present to allow S-phase entry. These observations revise our understanding of cell cycle progression by demonstrating that CDK1 physiologically regulates two distinct transitions during cell division cycle, whereas CDC7 has a redundant function in DNA replication.In addition to CDC7, the cell cycle kinase CDK1 has a pivotal role in the G1/S transition of cells, a finding that revises our current understanding of cell cycle progression. [ABSTRACT FROM AUTHOR]

Metallothionein-3 has poorly characterized functions in neuroblastoma. Cisplatin-based chemotherapy is a major regimen to treat neuroblastoma, but its clinical efficacy is limited by chemoresistance. We investigated the impact of human metallothionein-3 (hMT3) up-regulation in neuroblastoma cells and the mechanisms underlying the cisplatin-resistance. We confirmed the cisplatin-metallothionein complex formation using mass spectrometry. Overexpression of hMT3 decreased the sensitivity of neuroblastoma UKF-NB-4 cells to cisplatin. We report, for the first time, cisplatin-sensitive human UKF-NB-4 cells remodelled into cisplatin-resistant cells via high and constitutive hMT3 expression in an in vivo model using chick chorioallantoic membrane assay. Comparative proteomic analysis demonstrated that several biological pathways related to apoptosis, transport, proteasome, and cellular stress were involved in cisplatin-resistance in hMT3 overexpressing UKF-NB-4 cells. Overall, our data confirmed that up-regulation of hMT3 positively correlated with increased cisplatin-chemoresistance in neuroblastoma, and a high level of hMT3 could be one of the causes of frequent tumour relapses. [ABSTRACT FROM AUTHOR]

To date, there has been no evidence regarding the association between urinary sarcosine content and prostate cancer survival. Our main objective was to investigate whether levels of post‐treatment urinary sarcosine are associated with relapse. The inclusion criteria were (in accordance with EAU 2017) as follows: histopathologically verified adenocarcinoma in prostate biopsy cores or specimens from transurethral resection of the prostate (TURP) or prostatectomy for benign prostatic enlargement (BPE) with retained ability to urinate. The median follow‐up was 53 months. In the study, we retrospectively evaluated a cohort of 511 patients with prostate cancer with various risk factors and treatment strategies. Post‐treatment sarcosine levels were elevated in 266 (52%) patients and highly elevated (≥200 nmol/L) in 71 (13%) patients. Urinary sarcosine content was significantly associated with number of relapses that patients experienced, P = 0.002 for sarcosine ≥200 vs ≤30 nmol/L. Multivariate analysis revealed that sarcosine was an independent predictor of recurrent relapses (≥2 relapses with an intermediate period of remission), HR = 3.89 (95% CI 1.29‐11.7) for sarcosine >200 vs <30 nmol/L. This trend was even more pronounced in a subgroup of patients who underwent radical prostatectomy, HR = 3.29 (95% CI 1.06‐10.18), where (single) relapse‐free survival could also be predicted by sarcosine levels, HR = 1.96 (1.05‐3.66). Urinary sarcosine may become a possible predictor for patients' outcomes, because patients with elevated post‐treatment sarcosine could be predicted to have recurrent relapses of the disease. Risk of relapses is increased in prostate cancer patients with high post‐treatment urinary sarcosine, as shown by a retrospective study on 511 patients. [ABSTRACT FROM AUTHOR]

The current study aims at preparing biocompatible hybrid organic-inorganic ruthenium core-shell nanostructures (RuNPs) coated with polyvinylpyrrolidone (PVP) and polyoxyethylene stearate (POES). Thereafter, the core/shell RuNPs are loaded with doxorubicin (to form RuPDox) with a loading efficiency > 60%. RuPDox possesses exceptional stability and pH-responsive release kinetics with approx. 50% release of doxorubicin at up to 1 h exposure to an acidic endosomal environment. The cytotoxic effects of RuPDox are tested in vitro against breast cancer (MDA-MB-231), ovarian cancer (A2780), and neuroblastoma (UKF-NB-4) cells. Notably, although RuNPs have slight cytotoxicity only, RuPDox causes a synergistic enhancement of cytotoxicity when compared to free doxorubicin. Significant increase in free radicals formation, enhanced activity of executioner caspases 3/7, and higher expression of p53 and metallothionein is further identified due to the RuPDox treatment. Single-cell gel electrophoresis reveals no additional contribution of RuNPs to genotoxicity of doxorubicin. Moreover, RuPDox promotes significantly increased stability of doxorubicin in human plasma and pronounced hemocompatibility assayed on human red blood cells. The results imply a high potential of biocompatible hybrid RuNPs with PVP-POES shell as versatile nanoplatforms to enhance the efficiency of cancer treatment. [ABSTRACT FROM AUTHOR]

The correct TEM micrograph showing Dox-loaded RuPDox is shown below. B 2017 b , I 34 i , 1700289 DOI: 10.1002/ppsc.201700289 In this originally published article it was inadvertently used two adjacent transmission electron microscopy (TEM) micrographs, both showing non-loaded RuNPs (Figure 1D). PH-Responsive Hybrid Organic-Inorganic Ruthenium Nanoparticles for Controlled Release of Doxorubicin. [Extracted from the article]

Background: Suitable fluorophores are the core of fluorescence imaging. Among the most exciting, yet controversial, labels are quantum dots (QDs) with their unique optical and chemical properties, but also considerable toxicity. This hinders QDs applicability in living systems. Surface chemistry has a profound impact on biological behavior of QDs. This study describes a two-step synthesis of QDs formed by CdTe core doped with Schiff base ligand for lanthanides [Ln (Yb3+, Tb3+ and Gd3+)] as novel cytocompatible fluorophores. Results: Microwave-assisted synthesis resulted in water-soluble nanocrystals with high colloidal and fluorescence stability with quantum yields of 40.9–58.0%. Despite induction of endocytosis and cytoplasm accumulation of Yb- and TbQDs, surface doping resulted in significant enhancement in cytocompatibility when compared to the un-doped CdTe QDs. Furthermore, only negligible antimigratory properties without triggering formation of reactive oxygen species were found, particularly for TbQDs. Ln-doped QDs did not cause observable hemolysis, adsorbed only a low degree of plasma proteins onto their surface and did not possess significant genotoxicity. To validate the applicability of Ln-doped QDs for in vitro visualization of receptor status of living cells, we performed a site-directed conjugation of antibodies towards immuno-labeling of clinically relevant target—human norepinephrine transporter (hNET), over-expressed in neuroendocrine tumors like neuroblastoma. Immuno-performance of modified TbQDs was successfully tested in distinct types of cells varying in hNET expression and also in neuroblastoma cells with hNET expression up-regulated by vorinostat. Conclusion: For the first time we show that Ln-doping of CdTe QDs can significantly alleviate their cytotoxic effects. The obtained results imply great potential of Ln-doped QDs as cytocompatible and stable fluorophores for various bio-labeling applications. [ABSTRACT FROM AUTHOR]