Structural analysis of the Sulfolobus solfataricus MCM protein N-terminal domain†

The Mini-Chromosome Maintenance (MCM) proteins are candidates of replicative DNA helicase in eukarya and archaea. Here we report a 2.8 Å crystal structure of the N-terminal domain (residues 1–268) of the Sulfolobus solfataricus MCM (Sso MCM) protein. The structure reveals single-hexameric ring-like architecture, at variance from the protein of Methanothermobacter thermoautotrophicus (Mth). Moreover, the central channel in Sso MCM seems significantly narrower than the Mth counterpart, which appears to more favorably accommodate single-stranded DNA than double-stranded DNA, as supported by DNA-binding assays. Structural analysis also highlights the essential role played by the zinc-binding domain in the interaction with nucleic acids and allows us to speculate that the Sso MCM N-ter domain may function as a molecular clamp to grasp the single-stranded DNA passing through the central channel. On this basis possible DNA unwinding mechanisms are discussed

Topotecan-vincristine-doxorubicin in stage 4 high risk neuroblastoma patients failing to achieve a complete metastatic response to rapid COJEC : a SIOPEN study

Purpose : Metastatic response to induction therapy for high-risk neuroblastoma is a prognostic factor. In the International Society of Paediatric Oncology Europe Neuroblastoma (SIOPEN) HR-NBL-1 protocol, only patients with metastatic complete response (CR) or partial response (PR) with <= three abnormal skeletal areas on iodine 123-metaiodobenzylguanidine ([I-123] mIBG) scintigraphy and no bone marrow disease proceed to high dose therapy (HDT). In this study, topotecan-vincristine-doxorubicin (TVD) was evaluated in patients failing to achieve these criteria, with the aim of improving the metastatic response rate. Materials and Methods : Patients with metastatic high-risk neuroblastoma who had not achieved the SIOPEN criteria for HDT after induction received two courses of topotecan 1.5 mg/m(2)/day for 5 days, followed by a 48-hour infusion of vincristine, 2 mg/m(2), and doxorubicin, 45 mg/m(2). Results : Sixty-three patients were eligible and evaluable. Following two courses of TVD, four (6.4%) patients had an overall CR, while 28 (44.4%) had a PR with a combined response rate of 50.8% (95% confidence interval [CI], 37.9 to 63.6). Of these, 23 patients achieved a metastatic CR or a PR with <= 3 mIBG skeletal areas and no bone marrow disease (36.5%; 95% CI, 24.7 to 49.6) and were eligible to receive HDT. Toxicity was mostly haematological, affecting 106 of the 126 courses (84.1%; 95% CI, 76.5 to 90.0), and dose reduction was necessary in six patients. Stomatitis was the second most common nonhematological toxicity, occurring in 20 patients (31.7%). Conclusion : TVD was effective in improving the response rate of high-risk neuroblastoma patients after induction with COJEC enabling them to proceed to HDT. However, the long-term benefits of TVD needs to be determined in randomized clinical trials

Hematopoetic stem cell transplantation for solid tumors in Europe

Background: Hematopoetic stem cell transplants (HSCT) are discussed as treatment options for patients with solid tumors. Transplant numbers have changed substantially over the last decade, few controlled studies are available and different opinions prevail. Objective information on current practice is needed. Patients and methods: Data from 27 902 HSCT for solid tumors (2% allogeneic, 98% autologous), collected by the European Group for Blood and Marrow Transplantation (EBMT) activity survey from 1991 to 2002 were used to assess trends, transplant rates and coefficient of variation of transplant rates in Europe. Results: Transplant numbers increased from 536 in 1991 to 4154 in 1997 and decreased to 1913 in 2002. Indications were neuroblastoma (2504 HSCT; 9%), glioma (662 HSCT; 2%), soft tissue sarcoma (1253 HSCT; 4%), germ cell cancer (3291 HSCT; 12%), breast cancer (13 524 HSCT; 48%), Ewing's sarcoma (1896 HSCT; 7%), lung cancer (387 HSCT; 1%), ovarian cancer (845 HSCT; 3%) and other solid tumors (3540 HSCT; 14%). Allogeneic cells were used in <20 cases up to 1997; since then allogeneic HSCT increased to 159 in 2002, mainly for renal cell carcinoma. Low coefficients of variation in transplant rates (<60%) are observed for Ewing's sarcoma (<56.5%), suggesting consensus for this indication. Conclusions: These data give an overview on current practice of HSCT for solid tumors in Europe. They provide objective information for health-care providers and patient counsellin

Structures of heat shock factor trimers bound to DNA

Summary: Heat shock factor 1 (HSF1) and 2 (HSF2) play distinct but overlapping regulatory roles in maintaining cellular proteostasis or mediating cell differentiation and development. Upon activation, both HSFs trimerize and bind to heat shock elements (HSEs) present in the promoter region of target genes. Despite structural insights gained from recent studies, structures reflecting the physiological architecture of this transcriptional machinery remains to be determined. Here, we present co-crystal structures of human HSF1 and HSF2 trimers bound to DNA, which reveal a triangular arrangement of the three DNA-binding domains (DBDs) with protein-protein interactions largely mediated by the wing domain. Two structural properties, different flexibility of the wing domain and local DNA conformational changes induced by HSF binding, seem likely to contribute to the subtle differential specificity between HSF1 and HSF2. Besides, two more structures showing DBDs bound to “two-site” head-to-head HSEs were determined as additions to the published tail-to-tail dimer-binding structures

OTHR-02. One-year follow-up of the new ERN PaedCan CNS tumor board: lessons learnt and future prospects [Abstract]

BACKGROUND European Reference Networks (ERN) are collaborative networks connecting healthcare professionals across Europe. A virtual tumor board for pediatric patients with central nervous system (CNS) tumors was established within the ERN for pediatric oncology (ERN PaedCan) in September 2022. We report the feasibility, the implementation of recommendations and satisfaction of the participants. METHODS A web-based questionnaire was distributed to physicians presenting cases between November 2022 and November 2023. Questions addressed the implementation of recommendations, satisfaction and basic information about the local institution. Basic data of the presented cases were taken from anonymized tumor board protocols. RESULTS In the first year, 19 patients from 11 institutions located in nine European countries were discussed in 21 tumor boards. Median age at diagnosis was 10 (1-17) years. Demonstration of MRI findings by the German national reference center for neuroradiology was conducted in 19/21 conferences. 18/21 questionnaires (86%) were answered by physicians from eight countries. Main reason to request the discussion were questions about therapy (78%, n=14/18). Inquiring institutions treated a median of 10 (5-150) neuro-oncological pediatric patients per year. All hospitals conducted own institutional tumor boards. National central review was available in 3/8 countries (38%). Recommendations were followed, at least partly, in all cases except for one patient experiencing unexpected clinical deterioration. Recommendations were deemed helpful in 89%. All participants would recommend the tumor board to colleagues. Technical issues regarding data provision were reported as the main obstacle in 50 %. CONCLUSIONS A European virtual tumor board for pediatric patients with CNS tumors is feasible and perceived as useful by the participating institutions. Recommendations were followed frequently. Optimization of privacy-compliant data exchange is crucial for continuance of the format. This project has been supported by ERN PaedCan, which is funded by the European Union within the EU4Health Program 2021-2027. Funded by EU-grant 101085543

Systemic levels of neuropeptide Y and dipeptidyl peptidase activity in patients with Ewing sarcoma—Associations with tumor phenotype and survival

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110734/1/cncr29090.pd

Evaluation of semi-quantitative scoring system for metaiodobenzylguanidine (mIBG) scans in patients with relapsed neuroblastoma

Background The purpose of this study was to determine the accuracy of two semi-quantitative scoring systems to assess response to 131 I-metaiodobenzylguanidine (mIBG) therapy in recurrent neuroblastoma. Procedures Diagnostic mIBG scan pairs (n = 57) were collected for patients who underwent 131 I-mIBG therapy for relapsed neuroblastoma. Two scoring systems were designated: Method 1, which divided the body into nine segments to view osteomedullary lesions with an additional tenth segment to assess soft tissue involvement; and Method 2, which divided the body into seven segments without a corresponding compartment for soft tissue involvement. Four nuclear medicine physicians independently assigned extension and intensity scores utilizing both methods, and separately recorded their impression of whether the post-therapy scan had improved, not changed, or worsened. Inter- and intra-observer concordance and correlation with overall response and progression-free survival (PFS) were performed. Results Method 1 produced the highest inter-observer concordance and was used to calculate the relative extension scores (post-therapy score divided by pre-therapy score), which correlated significantly with overall response. Patients who achieved complete response (CR) or partial response (PR) (n = 21) had lower relative extension scores, compared to those without response ( P  5. Relative extension score did not predict PFS. Conclusion Semi-quantitative scoring of mIBG scans provides a more reliable method of assessing response in patients with relapsed neuroblastoma than qualitative impression. The reproducibility and high inter-observer concordance makes mIBG score an important component of overall response criteria in patients with recurrent neuroblastoma. Pediatr Blood Cancer © 2006 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55847/1/20777_ftp.pd