Published by The Company of Biologists Ltd.Different stem cells or progenitor cells display variable threshold requirements for functional ribosomes. This is particularly true for several human ribosomopathies in which select embryonic neural crest cells or adult bone marrow stem cells, but not others, show lethality due to failures in ribosome biogenesis or function (now known as nucleolar stress). To determine if various Drosophila neuroblasts display differential sensitivities to nucleolar stress, we used CRISPR-Cas9 to disrupt the Nopp140 gene that encodes two splice variant ribosome biogenesis factors (RBFs). Disruption of Nopp140 induced nucleolar stress that arrested larvae in the second instar stage. While the majority of larval neuroblasts arrested development, the Mushroom Body (MB) neuroblasts continued to proliferate as shown by their maintenance of deadpan, a neuroblast-specific transcription factor, and by their continued EdU incorporation. MB neuroblasts in wild type larvae appeared to contain more fibrillarin and Nopp140 in their nucleoli as compared to other neuroblasts, indicating that MB neuroblasts stockpile RBFs as they proliferate in late embryogenesis while other neuroblasts normally enter quiescence. SEL120 molecular weight A greater abundance of Nopp140 encoded by maternal transcripts in Nopp140-/- MB neuroblasts of 1-2 day old larvae likely rendered these cells more resilient to nucleolar stress. © 2020. Published by The Company of Biologists Ltd.An experimental technique called difference topology combined with the mathematics of tangle analysis has been used to unveil the structure of DNA bound by the Mu transpososome. However, difference topology experiments can be difficult and time-consuming. We discuss a modification that greatly simplifies this experimental technique. This simple experiment involves using a topoisomerase to trap DNA crossings bound by a protein complex and then running a gel to determine the crossing number of the knotted product(s). We develop the mathematics needed to analyze the results and apply these results to model the topology of DNA bound by 13S condensin and by the condensin MukB. © 2020. Published by The Company of Biologists Ltd.This study aimed to investigate the frequency of the somatic BRAF p.V600E in patients with colorectal cancer (CRC) in Mexico and compare it with those estimated for Latin American and Caribbean populations. One hundred and one patients with CRC with AJCC stages ranging I-IV from Western Mexico were included, out of which 55% were male and 61% had AJCC stage III-IV, with a mean age of 60 years. PCR-Sanger sequencing was used to identify the BRAF p.V600E variant. In addition, a systematic literature search in PubMed/Medline database and Google of the 42 countries in Latin America and the Caribbean led to the collection of information on the BRAF p.V600E variant frequency of 17 population reports. To compare the BRAF variant prevalence among populations, a statistical analysis was performed using GraphPad Prism V.6.0. We found that 4% of patients with CRC were heterozygous for the p.V600E variant. The χ2 test showed no significant difference (p>0.05) in p.V600E detection when comparing with other Latin American and Caribbean CRC populations, except for Chilean patients (p=0.02). Our observational study provides the first evidence on the frequency of BRAF p.V600E in patients with CRC from Western Mexico, which is 4%, but increases to 7.8% for all of Latin America and the Caribbean. The patient mean age and genetic descent on the observed frequencies of the variant in populations could influence the frequency differences. © American Federation for Medical Research 2020. Re-use permitted under CC BY-NC. No commercial re-use. Published by BMJ.Cruciferous vegetables have been of special interest due to the rich presence of bioactive compounds such as sulforaphane which show promising potential on cancer prevention and therapy as an epigenetic dietary strategy. Abnormal epigenetic alteration as one of the primary contributors to tumor development is closely related to breast cancer initiation and progression. In the present study, we investigated the effect of dietary broccoli sprouts (BSp), a common cruciferous vegetable, on prevention of estrogen receptor (ER)-negative mammary tumors at three different temporal exposure windows using a spontaneous breast cancer mouse model. Our findings indicate that maternal BSp treatment exhibited profound inhibitory and preventive effects on mammary cancer formation in the nontreated mouse offspring. The BSp diet administered to adult mice also showed suppressive effects on mammary cancer but was not as profound as the maternal BSp preventive effects. Moreover, such protective effects were linked with differentially expressed tumor- and epigenetic-related genes, as well as altered global histone acetylation, DNA methylation and DNA hydroxymethylation levels. We also found that the expression changes of tumor-related genes were associated with the levels of histone methylation of H3K4 and H3K9 in the gene promoter regions. In addition, BSp-enriched sulforaphane was shown to increase protein expression of tumor suppressor genes such as p16 and p53 and inhibit the protein levels of Bmi1, DNMTs and HDACs in ERα-negative breast cancer cell lines. Collectively, these results suggest that maternal exposure to key phytochemicals may contribute to ER-negative mammary tumor prevention in their offspring through epigenetic regulations. Copyright ©2020, American Association for Cancer Research.BACKGROUND AND PURPOSE We evaluated modifications to our contrast-enhanced MR imaging grading system for symptomatic patients with suspected nasopharyngeal carcinoma, aimed at improving discrimination of early-stage cancer and benign hyperplasia. We evaluated a second non-contrast-enhanced MR imaging grading system for asymptomatic patients from nasopharyngeal carcinoma plasma screening programs. MATERIALS AND METHODS Dedicated nasopharyngeal MR imaging before (plain scan system) and after intravenous contrast administration (current and modified systems) was reviewed in patients from a nasopharyngeal carcinoma-endemic region, comprising 383 patients with suspected disease without nasopharyngeal carcinoma and 383 patients with nasopharyngeal carcinoma. The modified and plain scan systems refined primary tumor criteria, added a nodal assessment, and expanded the system from 4 to 5 grades. The overall combined sensitivity and specificity of the 3 systems were compared using the extended McNemar test (a χ2 value [Formula see text]> 5.