Impediments in replication fork progression cause genomic instability, mutagenesis, and severe pathologies. At stalled forks, RPA-coated single-stranded DNA (ssDNA) activates the ATR kinase and ...directs fork remodeling, 2 key early events of the replication stress response. RFWD3, a recently described Fanconi anemia (FA) ubiquitin ligase, associates with RPA and promotes its ubiquitylation, facilitating late steps of homologous recombination (HR). Intriguingly, RFWD3 also regulates fork progression, restart and stability via poorly understood mechanisms. Here, we used proteomics to identify putative RFWD3 substrates during replication stress in human cells. We show that RFWD3 interacts with and ubiquitylates the SMARCAL1 DNA translocase directly in vitro and following DNA damage in vivo. SMARCAL1 ubiquitylation does not trigger its subsequent proteasomal degradation but instead disengages it from RPA thereby regulating its function at replication forks. Proper regulation of SMARCAL1 by RFWD3 at stalled forks protects them from excessive MUS81-mediated cleavage in response to UV irradiation, thereby limiting DNA replication stress. Collectively, our results identify RFWD3-mediated SMARCAL1 ubiquitylation as a novel mechanism that modulates fork remodeling to avoid genome instability triggered by aberrant fork processing.
Abstract Objective To assess operative and pathological results obtained after robot-assisted partial nephrectomy (RAPN) in renal masses over 4 cm. Patients and methods Between 2007 and 2011, 220 ...robotic nephron-sparing surgeries (NSS) were performed at six French urology departments. Data were prospectively collected: age, BMI, pre and post-operative eGFR (MDRD), operative time (OT), warm ischemia time (WIT), estimated blood loss (EBL), length of hospital stay (LOS), Clavien complications, pathological results and oncologic outcome. Tumor complexity was assessed according to the RENAL nephrometry score. Results Overall, 54 tumors were included. Median follow up was 26 months. Median age at surgery was 62 years. Median RENAL nephrometry score was 7 (4–10). Median WIT was 23 min (10–59). Median OT and EBL were 180 min (110–425) and 100 cc (0–2500). Blood transfusion occurred in 7 cases (13%). Median tumor size was 45 mm (40–70). Three patients had positive surgical margins. Median LOS was 5 days (2–28). Nine patients presented post-operative complications of which 1/3 were considered as major (Clavien IIIb). Median pre-operative and post-operative eGFR was 88 (36–136) and 75 ml/min (33–122) ( p = 0.01), respectively. Two patients developed subsequent metastasis. The 2-year progression free survival (PFS) rate was 90.5%. Conclusion Our results confirm that RAPN is a useful and acceptable approach for renal masses greater than 4 cm in size. When technically possible, NSS provides promising short-term cancer-specific survival rates with acceptable morbidity. Tumor size is not sufficiently discriminant enough and RENAL nephrometry score should increasingly used to describe tumor complexity.
Cartilage degeneration after injury affects a significant percentage of the population, including those that will go on to develop osteoarthritis (OA). Like humans, most mammals, including mice, are ...incapable of regenerating injured cartilage. Interestingly, it has previously been shown that
(
) knockout (p21
) mice demonstrate auricular (ear) cartilage regeneration. However, the loss of p21 expression is highly correlated with the development of numerous types of cancer and autoimmune diseases, limiting the therapeutic translation of these findings. Therefore, in this study, we employed a screening approach to identify an inhibitor (17-DMAG) that negatively regulates the expression of p21. We also validated that this compound can induce chondrogenesis
(in adult mesenchymal stem cells) and
(auricular cartilage injury model). Furthermore, our results suggest that 17-DMAG can induce the proliferation of terminally differentiated chondrocytes (
and
), while maintaining their chondrogenic phenotype. This study provides new insights into the regulation of chondrogenesis that might ultimately lead to new therapies for cartilage injury and/or OA.
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