Cyclin-dependent kinase-dependent phosphorylation of Lif1 and Sae2 controls imprecise nonhomologous end joining accompanied by double-strand break resection

DNA double-strand breaks (DSBs) are repaired by two distinct pathways, homologous recombination (HR) and nonhomologous end joining (NHEJ). NHEJ includes two pathways, that is, precise and imprecise end joining. We found that Lif1, a component of the DNA ligase IV complex in Saccharomyces cerevisiae, was phosphorylated by cyclin-dependent kinase (CDK) at Ser261 during the S to G2 phase but not during G1 phase. This phosphorylation was required for efficient NHEJ in G2/M cells, rather than in G1 cells. It also promotes the stable binding of Lif1 protein to DSBs, specifically in G2/M-arrested cells, which shows the resection of DSB ends. Thus, Lif1 phosphorylation plays a critical role in a certain type of imprecise NHEJ accompanied by DSB end resection and micro-homology. Lif1 phosphorylation at Ser261 is probably involved in micro-homology-dependent end joining associated with producing single-stranded DSB ends that are formed by Sae2 as early intermediates in the HR pathway. CDK-dependent modification of the NHEJ pathway might make DSB ends compatible for NHEJ and thus prevent competition between HR and NHEJ in hierarchy on the choice of DSB repair pathways.     

Liver structures of a patient with idiopathic copper toxicosis

This is the first report describing the liver structures of a Japanese patient with idiopathic copper toxicosis, which should be differentiated from hepatolenticular degeneration of Wilson disease. An 11-year-old Japanese boy presented with ascites associated with biochemical liver damage. Involvement of hepatitis virus was ruled out by laboratory tests. Because urinary copper excretion was increased, Wilson disease was highly suspected, but the serum level of ceruloplasmin was normal, and Kayser-Fleischer rings were not detected by slit lamp examination. Brain images were within normal limits. ATP7B analysis was negative for mutations. Liver specimen showed cirrhosis associated with chronic active hepatitis. Almost all hepatocytes were positive for orcein-stained granules. Mallory bodies were found in some hepatocytes. Fatty change was minimal, and there were no glycogenated nuclei in the parenchyma. Combined regimens of trientine and zinc for 6 months improved the decompensated state of liver function. After 2.5 years of treatment, a second liver biopsy was performed. The post-treatment liver showed complete disappearance of portal inflammation and remarkable decrease in cuprothionein granules. Mallory bodies disappeared from the parenchyma. An abundance of hepatocellular Mallory bodies and heavy copper loading limited to the liver may be specific to idiopathic copper toxicosis.     

Interleukin-6 signalling regulates vascular endothelial growth factor-C synthesis and lymphangiogenesis in human oral squamous cell carcinoma

Lymph node metastasis is associated with resistance to conventional therapy and poor survival of patients with oral squamous cell carcinoma (OSCC). Although lymphangiogenesis is well known to be associated with the occurrence of lymph node metastasis in various cancers, the precise mechanisms of lymphangiogenesis in OSCC are largely unknown. IL-6, a potent pro-inflammatory cytokine, has been shown to play active roles in various cancers, including OSCC. This study aimed to investigate the involvement of IL-6 signalling in lymphatic metastasis and to evaluate the efficacy of tocilizumab, a humanized anti-human IL-6 receptor antibody, as an anti-lymphangiogenic agent for OSCC. This investigation confirmed that levels of expression of IL-6 protein and VEGF-C mRNA in OSCC tissues were significantly correlated with lymph node metastasis in patients with OSCC, as assessed by immunohistochemical analysis and real-time quantitative RT-PCR. In vitro studies showed that IL-6 regulated VEGF-C mRNA expression in a human OSCC cell line, SAS cells, through the phosphoinositide 3-kinase-Akt pathway. In addition, treatment with tocilizumab led to markedly reduced VEGF-C mRNA expression and OSCC-related lymphangiogenesis in SAS xenografts. Together, these data suggest that tocilizumab acted as expected: it inhibited lymph node metastasis in OSCC by reducing tumour lymphangiogenesis.     

Mps3 SUN domain is important for chromosome motion and juxtaposition of homologous chromosomes during meiosis

In budding yeast, Mps3 is essential for duplicating the spindle pole body (SPB) and is critical for promoting chromosome motion during meiosis. It is a member of the SUN (Sad1-Unc-84) domain family of proteins that localizes to the inner nuclear envelope (NE) in many eukaryotic organisms and preferentially localizes to the SPB in vegetative growth; in meiotic prophase I, it redistributes to many sites within the NE. We constructed an mps3 mutant, mps3-sun, which completely lacks the SUN domain. Surprisingly, the mps3-sun mutation does not disrupt SPB duplication or Mps3 localization to the NE in meiosis. However, it confers several defects during meiotic prophase I including reduced chromosome motion, premature synapsis between homologous chromosomes, and reduced levels of closely juxtaposed homologous loci in pachytene. These findings suggest that in meiosis, the Mps3 SUN domain is important for modulating chromosome motion events that act in meiotic chromosome juxtaposition and by extension, promoting proper morphogenesis of the synaptonemal complex.     

Dectin-1 limits autoimmune neuroinflammation and promotes myeloid cell-astrocyte crosstalk via Card9-independent expression of Oncostatin M

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Overview and update on molecular testing in non-small cell lung carcinoma utilizing endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples

Lung carcinoma remains one of the most frequent and aggressive human neoplasms. Fortunately, in the last decades, the increasing knowledge of the molecular mechanisms leading to cancer development has allowed the use of targeted therapies with improvement of prognosis in many patients. Clinical management has also changed after the introduction of endobronchialultrasonographic bronchoscopy that allows a conservative staging of lung tumors, avoiding the need of mediastinoscopy for lymph node staging. Lung pathologists and cytopathologists are facing the challenge of giving the more comprehensive prognostic and predictive information with ever smaller tissue or cytological samples. The aim of this review is to summarize the molecular testing for non-small cell lung carcinoma and how pathologists can contribute to the patient's outcome with a conscious management of biological samples.     

A new class of tissue-specifically methylated regions involving entire CpG islands in the mouse

CpG islands, which have higher GC content and CpG frequencies compared to the genome as a whole, are generally believed to be unmethylated in tissues except at promoters of genes undergoing X chromosome inactivation or genomic imprinting. Recent studies, however, have shown that CpG islands at promoters of a number of genes contain tissue-dependent, differentially methylated regions (T-DMRs). In general, the tissue-specific methylation is restricted to a part of the promoter CpG island, with hypomethylation of the remaining sequence. In the current study, using comparison between Restriction Landmark Genomic Scanning (RLGS) and in silico RLGS, we identified ten sperm-specific unmethylated NotI sites, T-DMRs located in CpG islands that were hypomethylated in sperm but near-completely methylated in the kidney and brain. Unusually, these T-DMRs involve the whole CpG island at each of these loci. We characterized one of these genes, adenine nucleotide translocator 4 (Ant4), which is expressed in germ cells. Using a promoter assay, we demonstrated that expression of Ant4 gene is controlled by DNA methylation at the CpG island sequences within the promoter region. Ant4 and other sperm-specific hypomethylated loci represent a new class of CpG islands that become completely methylated in different cell lineages. T-DMRs at CpG islands are functionally important gene regulatory elements that may now be categorized into two classes: T-DMRs involving a subregion of the CpG island and those that occupy the whole CpG island.     

Case of minocycline-induced pneumonitis with bilateral pleural effusion]

A 51-year-old man was admitted to our hospital with fever, dry cough and dyspnea. He had taken minocycline for 11 days because of urinary tract infection. Chest X-ray on admission showed diffuse reticular shadows in bilateral lung fields with bilateral pleural effusion. Cessation of minocycline led to spontaneous improvement of symptoms and radiographic findings. The lymphocyte stimulation test for minocycline with peripheral blood and pleural effusion were negative. After provocation test with minocycline, he developed fever and dry cough and bilateral ground glass opacity appeared on his chest X-ray. He was diagnosed as minocycline-induced pneumonitis and recovered rapidly following corticosteroid therapy.     

Isolation and characterization of native Cry j 3 from Japanese cedar (Cryptomeria japonica) pollen

BACKGROUND: Japanese cedar (Cryptomeria japonica) pollinosis is the most prevalent allergy in Japan. Recently, the Japanese cedar pollen allergen Cry j 3 was cloned as a homologue of Jun a 3, which is a major allergen from mountain cedar (Juniperus ashei) pollen. However, native Cry j 3 has not been isolated and there are no reports on its allergenic activity. The aims of this study were to isolate native Cry j 3 and assess its immunoglobulin E (IgE)-binding capacity in patients with Japanese cedar pollinosis. METHODS: Native Cry j 3 was purified from Japanese cedar pollen by multidimensional chromatography. We assessed the IgE-binding capacity using sera from patients allergic to Japanese cedar pollen by immunoblot analysis and ELISA. Moreover, we assayed the capacity of Cry j 3 to induce histamine release from the patients' leukocytes. We cloned cDNA corresponding to purified Cry j 3 from a cDNA library of Japanese cedar pollen. RESULTS: We isolated native Cry j 3 as a 27-kDa protein. The IgE-binding frequency of Cry j 3 from the sera of patients allergic to Japanese cedar pollen was estimated as 27% (27/100) by ELISA. Cry j 3 induced the release of histamine from leukocytes. We cloned the cDNA and named it Cry j 3.8. Cry j 3.8 cDNA encoded 225 amino acids and had significant homology with thaumatin-like proteins. CONCLUSIONS: Cry j 3 is a causative allergen in Japanese cedar pollinosis and may play crucial roles in the cross-reactivity with oral allergy syndrome.     

Z‐axis video for cytology database is a useful tool for the case presentation prior to the cytology training workshop

We have built a database on the Internet managing z‐axis video for cytology (Zavic), and report on a new style of case discussion supported by the Zavic database. Z‐axis video for cytology is a movie file derived from the video recording of a microscopic field with changes in the focus. We used it for the case presentation of EUS‐FNA of pancreatic lesions on the Internet prior to a training workshop. The attendees were asked to observe the Zavic and to make diagnoses of 20 cases before the workshop. Fourteen attendees also observed lesions under a microscope on that day, and the results were compared with those of Zavic observation. The evaluation of the Zavic database (DB) was surveyed by a questionnaire. The average number of accurate diagnoses by 46 Zavic observers was 10.8. These accuracies for those who observed both the Zavic and glass slides were 11.57 and 11.43, respectively, for the videos and slides. Compared with Zavic observation alone, the diagnoses with glass slide observation were shifted to a correct diagnosis in two cases, but were shifted to an incorrect diagnosis in two cases. Approximately 60% of Zavic observers replied in the questionnaire that the movies on Zavic DB started to play within 3–4 seconds after clicking the play button. We successfully carried out the new style of case discussion supported by the Zavic DB. It was evaluated favorably by many attendees, who were psychologically still dependent on the glass slide observation. Diagn. Cytopathol. 2013. © 2011 Wiley Periodicals, Inc.