Role of CCNB1, CENPF, and neutrophils in lung cancer diagnosis and prognosis.

This study aimed to investigate CCNB1, CENPF, and Neutrophils as diagnostic predictors of lung cancer and to explore their association with clinical prognosis. Clinical data were obtained for a total of 52 patients. In addition, we downloaded 555 lung cancer-related samples from the cancer genome atlas (TCGA) database. Differentially expressed genes were further screened. Immune cell infiltration and survival analysis were performed. Immunohistochemistry was used to confirm gene expression. Peripheral blood analysis showed that neutrophil percentages were significantly reduced in patients with lung cancer. The least absolute shrinkage and selection operator and multivariate regression analysis revealed that CCNB1 and CENPF were lung cancer risk factors. Both CCNB1 and CENPF are overexpressed in lung cancer. The clinical diagnostic model constructed using CCNB1, CENPF, and neutrophils had a C-index of 0.994. This model area under the curve (AUC) and internal validation C-index values were 0.994 and 0.993, respectively. The elevated expression of CCNB1 and CENPF showed that the survival rate of lung cancer patients was reduced. CCNB1 and CENPF expression was positively correlated with the clinical stage of lung cancer. Further studies confirmed that CCNB1 and CENPF are overexpressed in lung cancer tissues. The clinically constructed model with high accuracy based on CCNB1, CENPF, and neutrophils demonstrated that these are crucial indicators for lung cancer diagnosis. High expression of CCNB1 and CENPF indicates a poor prognosis in patients with lung cancer.

Characterization of Opa interacting protein 5 as a new biomarker and therapeutic target for oral cancer.

Oral cancer is a leading cause of cancer­related death worldwide. Current treatment for oral cancer includes surgery, radiotherapy, and chemotherapy; however, their effectiveness is still limited. To identify a new prognostic biomarker and therapeutic target for oral cancer, the Opa interacting protein 5 (OIP5), which plays an essential role in the proper segregation of chromosomes, was examined. Immunohistochemical staining using tissue microarrays indicated that OIP5 was expressed in 120 of 164 (73.2%) oral cancers but was minimally expressed in normal oral tissues. OIP5 expression was significantly associated with poor prognosis in patients with oral cancer. Overexpression of OIP5 enhanced the growth of oral cancer cells, whereas OIP5 knockdown using small interfering RNAs (siRNAs) significantly inhibited cell growth through cell cycle arrest at the G2/M phase. Suppression of OIP5 expression also induced senescence of oral cancer cells. Overall, the findings of the present study suggest that OIP5 may be a candidate prognostic biomarker and therapeutic target in oral cancer.

Overexpression of CENPF is associated with progression and poor prognosis of lung adenocarcinoma.

Background and aim: The molecular signatures of lung adenocarcinoma (LUAD) are not well understood. Centromere protein F (CENPF) has been shown to promote oncogenesis in many cancers; however, its role in LUAD has not been illustrated. We explored the role of CENPF in LUAD. Methods: CENPF expression level was investigated in public online database firstly, the prognosis of CENPF in LUAD were also assessed by Kaplan-Meier analysis. Then quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was performed using 13 matched pairs of clinical LUAD tissue samples. Subsequently, the impact of CENPF expression on cell proliferation, cell cycle, apoptosis, colony formation was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), flow cytometric analysis and colony formation assay, respectively. Finally, experimental xenograft lung cancer model of nude mice armpit of right forelimb to determine the effect of CENPF on LUAD tumorigenesis. Results: CENPF mRNA expression was significantly elevated in LUAD tissues compared with adjacent non-tumor lung tissues in Gene Expression Profiling Interactive Analysis (GEPIA) (P < 0.001). Up-regulated CENPF was remarkably positively associated with pathological stage, relapse free survival (RFS) as well as overall survival (OS) of LUAD patients. Besides, CENPF knockdown greatly suppressed A549 cell proliferation, induced S phase arrest, promoted apoptosis and decreased colony numbers of LUAD cells. Furthermore, knockdown of CENPF significantly inhibited the tumor growth of the LUAD cells in an experimental xenograft lung cancer model of nude mice armpit of right forelimb. Conclusion: Taken together, these results demonstrated that CENPF may serve as a potential biomarker of prognostic relevance and a potential therapeutic target for LUAD.

SKA1 regulates actin cytoskeleton remodelling via activating Cdc42 and influences the migration of pancreatic ductal adenocarcinoma cells.

OBJECTIVES: Spindle and kinetochore-associated protein 1(SKA1), originally identified as a protein essential for proper chromosome segregation, has been recently linked to multiple malignancies. This study aimed to explore the biological, clinical role and molecular mechanism of SKA1 in pancreatic carcinogenesis. MATERIALS AND METHODS: SKA1 expression was detected in 145 pancreatic ductal adenocarcinoma (PDAC) specimens by immunohistochemistry. Biological behaviour assays were used to determine the role of SKA1 in PDAC progression in vitro and in vivo. Using isobaric tags for relative and absolute quantitation (iTRAQ), SKA1's downstream proteins were examined. Moreover, cytochalasin B and ZCL278 were used to explore the changes of SKA1-induced signalling and cell morphology, with further confirmation by immunoblotting and immunofluorescence assays. RESULTS: Increased SKA1 expression was significantly correlated with tumour size and cellular differentiation degree in PDAC tissues. Furthermore, elevated levels of SKA1 reflected shorter overall survival (P = .019). As for biological behaviour, SKA1 acted as a tumour promotor in PDAC, overexpression of SKA1 facilitates cell proliferation, migration and invasion in vitro and in vivo. Mechanistically, we demonstrated that SKA1 enhanced pancreatic cancer aggressiveness by inhibiting G2/M arrest and regulating actin cytoskeleton organization via activating Cdc42. CONCLUSIONS: This study revealed novel roles for SKA1 as an important regulator of actin cytoskeleton organization and an oncogene in PDAC cells, which may provide insights into developing novel therapeutics.

A multi-layered structure of the interphase chromocenter revealed by proximity-based biotinylation.

During interphase centromeres often coalesce into a small number of chromocenters, which can be visualized as distinct, DAPI dense nuclear domains. Intact chromocenters play a major role in maintaining genome stability as they stabilize the transcriptionally silent state of repetitive DNA while ensuring centromere function. Despite its biological importance, relatively little is known about the molecular composition of the chromocenter or the processes that mediate chromocenter formation and maintenance. To provide a deeper molecular insight into the composition of the chromocenter and to demonstrate the usefulness of proximity-based biotinylation as a tool to investigate those questions, we performed super resolution microscopy and proximity-based biotinylation experiments of three distinct proteins associated with the chromocenter in Drosophila. Our work revealed an intricate internal architecture of the chromocenter suggesting a complex multilayered structure of this intranuclear domain.

DEK Is a Potential Biomarker Associated with Malignant Phenotype in Gastric Cancer Tissues and Plasma.

Gastric cancer (GC) is the second most widespread cause of cancer-related mortality worldwide. The discovery of novel biomarkers of oncoproteins can facilitate the development of therapeutic strategies for GC treatment. In this study, we identified novel biomarkers by integrating isobaric tags for relative and absolute quantitation (iTRAQ), a human plasma proteome database, and public Oncomine datasets to search for aberrantly expressed oncogene-associated proteins in GC tissues and plasma. One of the most significantly upregulated biomarkers, DEK, was selected and its expression validated. Our immunohistochemistry (IHC) (n = 92) and quantitative real-time polymerase chain reaction (qRT-PCR) (n = 72) analyses disclosed a marked increase in DEK expression in tumor tissue, compared with paired nontumor mucosa. Importantly, significantly higher preoperative plasma DEK levels were detected in GC patients than in healthy controls via enzyme-linked immunosorbent assay (ELISA). In clinicopathological analysis, higher expression of DEK in both tissue and plasma was significantly associated with advanced stage and poorer survival outcomes of GC patients. Data from receiver operating characteristic (ROC) curve analysis disclosed a better diagnostic accuracy of plasma DEK than carcinoembryonic antigen (CEA), carbohydrate antigen 19.9 (CA 19.9), and C-reactive protein (CRP), highlighting its potential as an effective plasma biomarker for GC. Plasma DEK is also more sensitive in tumor detection than the other three biomarkers. Knockdown of DEK resulted in inhibition of GC cell migration via a mechanism involving modulation of matrix metalloproteinase MMP-2/MMP-9 level and vice versa. Our results collectively support plasma DEK as a useful biomarker for making diagnosis and prognosis of GC patients.

Modular Organization and Assembly of SWI/SNF Family Chromatin Remodeling Complexes.

Mammalian SWI/SNF (mSWI/SNF) ATP-dependent chromatin remodeling complexes are multi-subunit molecular machines that play vital roles in regulating genomic architecture and are frequently disrupted in human cancer and developmental disorders. To date, the modular organization and pathways of assembly of these chromatin regulators remain unknown, presenting a major barrier to structural and functional determination. Here, we elucidate the architecture and assembly pathway across three classes of mSWI/SNF complexes-canonical BRG1/BRM-associated factor (BAF), polybromo-associated BAF (PBAF), and newly defined ncBAF complexes-and define the requirement of each subunit for complex formation and stability. Using affinity purification of endogenous complexes from mammalian and Drosophila cells coupled with cross-linking mass spectrometry (CX-MS) and mutagenesis, we uncover three distinct and evolutionarily conserved modules, their organization, and the temporal incorporation of these modules into each complete mSWI/SNF complex class. Finally, we map human disease-associated mutations within subunits and modules, defining specific topological regions that are affected upon subunit perturbation.

Elevated DSN1 expression is associated with poor survival in patients with hepatocellular carcinoma.

Dosage suppressor of Nnf1 (DSN1) is a component of the kinetochore protein complex that is required for proper chromosome segregation. Some studies have explored that DSN1 is related to colorectal cancer progression. However, the role of DSN1 in hepatocellular carcinoma (HCC) remains unknown. This study aimed to explore DSN1 expression in HCC tissues. We obtained data from The Cancer Genome Atlas and Gene Expression Omnibus to analyze DSN1 expression in HCC. DSN1 mRNA expression was assessed in 30 pairs of HCC samples via reverse-transcription quantitative polymerase chain reaction. Immunohistochemical analysis of 95 HCC tissue specimens was performed to assess DSN1 expression and examine the clinicopathological characteristics of DSN1 in HCC. Results showed that DSN1 was upregulated in HCC tissues and was strongly associated with sex (P = .031), α-fetoprotein (P < .001), tumor size (P = .032), tumor nodule number (P = .028), cancer embolus (P = .011), and differentiation grade (P = .001). Moreover, Kaplan-Meier and Cox proportional-hazards analyses indicated that high DSN1 expression was related to poor HCC patient survival and that DSN1 can serve as an independent prognostic factor for overall survival and disease-free survival. In conclusion, our findings indicate that DSN1 could serve as a novel prognostic biomarker for HCC patients.

Chromatin assembly factor-1 (CAF-1) chaperone regulates Cse4 deposition into chromatin in budding yeast.

Correct localization of the centromeric histone variant CenH3/CENP-A/Cse4 is an important part of faithful chromosome segregation. Mislocalization of CenH3 could affect chromosome segregation, DNA replication and transcription. CENP-A is often overexpressed and mislocalized in cancer genomes, but the underlying mechanisms are not understood. One major regulator of Cse4 deposition is Psh1, an E3 ubiquitin ligase that controls levels of Cse4 to prevent deposition into non-centromeric regions. We present evidence that Chromatin assembly factor-1 (CAF-1), an evolutionarily conserved histone H3/H4 chaperone with subunits shown previously to interact with CenH3 in flies and human cells, regulates Cse4 deposition in budding yeast. yCAF-1 interacts with Cse4 and can assemble Cse4 nucleosomes in vitro. Loss of yCAF-1 dramatically reduces the amount of Cse4 deposited into chromatin genome-wide when Cse4 is overexpressed. The incorporation of Cse4 genome-wide may have multifactorial effects on growth and gene expression. Loss of yCAF-1 can rescue growth defects and some changes in gene expression associated with Cse4 deposition that occur in the absence of Psh1-mediated proteolysis. Incorporation of Cse4 into promoter nucleosomes at transcriptionally active genes depends on yCAF-1. Overall our findings suggest CAF-1 can act as a CenH3 chaperone, regulating levels and incorporation of CenH3 in chromatin.

SWI/SNF Chromatin-remodeling Complex Status in SMARCB1/INI1-preserved Epithelioid Sarcoma.

The SWI/SNF chromatin-remodeling complex, which is composed of evolutionarily conserved core subunits such as SMARCB1/INI1 (INI1), SMARCA4/BRG1 (BRG1), SMARCC1/BAF155 (BAF155), and SMARCC2/BAF170 (BAF170), can be viewed as the prototype of an epigenetic regulator of gene expression that is involved in tumor suppression. Epithelioid sarcoma, which classified as a tumor of uncertain differentiation, shows an almost complete loss of INI1. However, some cases of epithelioid sarcoma have preserved INI1, and the clinicopathologic features of these cases are uncertain. To date, there has been no investigation focused on the SWI/SNF chromatin-remodeling complex in INI1-preserved epithelioid sarcoma cases. First, an investigation of INI1 immunoexpression statuses in 60 formalin-fixed paraffin-embedded epithelioid sarcoma specimens (proximal type, 29 cases; conventional type, 31 cases) was performed. In the available INI1-preserved epithelioid sarcoma cases, we analyzed the BRG1, BAF155, and BAF170 protein expressions. INI1 preservation was observed in 6 of 29 (21%) proximal-type and 2 of 31 (6%) conventional-type epithelioid sarcoma cases. Six cases of INI1-preserved epithelioid sarcomas of proximal type were available for further immunohistochemical study. One proximal type showed loss of BAF170, and 2 proximal-type cases revealed loss of BRG1 with preservation of the other remaining core subunit proteins. One proximal-type case showed a mosaic pattern of BRG1 and loss of BAF155. However, in the remaining 2 proximal-type cases, all core subunit proteins were preserved. Overall, these results suggest that loss of expression of SWI/SNF chromatin-remodeling complex proteins has an important role in tumorigenesis. The remaining 2 INI1-preserved epithelioid sarcoma cases may have had other abnormalities causing dysfunction of SWI/SNF chromatin remodeling.

Extraocular sebaceous carcinoma accompanied by invasive squamous cell carcinoma: The first case report and consideration of histogenesis.

A 61-year-old man presented with a dome-shaped nodule, 1.2 cm in size, with a central crater covered by keratinous material near the left lateral malleolus. Histological findings demonstrated a basophilic circular cone in the center, surrounded and sharply demarcated by a broad eosinophilic area. The central conical mass was composed mainly of atypical basaloid cells intermingled with scattered atypical sebaceous cells with scalloped nuclei and microvesicular cytoplasms, suggesting sebaceous carcinoma. The peripheral area consisted of atypical keratinizing squamoid cells without sebaceous cells, suggesting invasive squamous cell carcinoma. Atypical sebaceous cells were positive for adipophilin. Atypical basaloid cells were positive for 34ßE12 and CAM5.2. Peripheral squamoid cells were positive for 34ßB4 and 34ßE12 throughout, and were positive for LHP1 in the superficial layer. We herein describe the first case of extraocular sebaceous carcinoma accompanied by invasive squamous cell carcinoma, which might have arisen from biphasic differentiation of cancer stem cells.

Psf3 is a prognostic biomarker in lung adenocarcinoma: a larger trial using tissue microarrays of 864 consecutive resections.

OBJECTIVES: Partner of Sld five (Psf) 3 is a member of the evolutionarily conserved heterotetrameric complex GINS (Go-Ichi-Ni-San). We previously reported that Psf3 could serve as a biomarker of poor prognosis in lung adenocarcinoma. Here, we used tissue microarrays to analyse Psf3 expression in lung adenocarcinoma and investigated whether its expression is associated with survival outcomes. METHODS: The study included 864 consecutive patients with lung adenocarcinoma who underwent complete resection at Hyogo Cancer Center between January 2002 and December 2009. Tissue microarrays were prepared, and Psf3 was detected using mouse antihuman Psf3 primary monoclonal antibodies. The status of Psf3 expression was determined using these microarrays. RESULTS: Of the 864 patients, 375 had high-positive Psf3 expression and 489 had low-positive expression. Psf3 expression was significantly associated with age, sex, T factor, lymph node metastasis, stage and P factor. The 5-year disease-free survival (DFS) rate was significantly lower in patients with high-positive Psf3 expression than in those with low-positive expression, and Psf3 expression, sex, age, T factor and lymph node metastasis were identified as independent and significant prognostic determinants. Among patients with Stage I adenocarcinoma, the 5-year DFS rate was significantly lower in those with high-positive Psf3 expression than in those with low-positive expression, and Psf3 expression was the most powerful survival predictor. CONCLUSIONS: The present findings strengthened our previous data demonstrating that high Psf3 expression in primary lung adenocarcinoma plays an important role in disease progression and is a prognostic indicator, particularly in early-stage adenocarcinoma.

Mitosin and pHH3 predict poorer survival in astrocytomas WHO grades II and III.

AIMS: The limitations of the current WHO classification of astrocytomas call for a sustained effort to improve diagnostic and prognostic accuracy. The relationship between tumour growth and clinical outcome suggests that proliferative activity should be examined. The objective of this study was to evaluate the diagnostic and prognostic value of the proliferation markers mitosin and phosphohistone H3 (pHH3) in infiltrative astrocytomas WHO grades II and III and compare the findings with mitotic count and Ki-67/MiB-1 immunostaining. METHODS: Fifty-nine and thirty-three infiltrative astrocytomas WHO grades II and III, respectively, were immunostained with the proliferation markers mitosin and pHH3 using standard immunohistochemical procedures. The expression was quantified as a proliferative index (PI) and statistically evaluated with Spearman's rank correlation test, Wilcoxon-Mann-Whitney U test, and univariable and multivariable COX regression survival analyses. RESULTS: Significant positive correlations were found between these proliferation markers. The number of mitoses, pHH3 mitotic figures (MFs), the Ki-67/MiB-1 PI and the mitosin PI were greater in WHOgrade III anaplastic astrocytomas compared to WHO grade II diffuse astrocytomas, while pHH3 PI only showed a trend. All proliferation markers were associated with poorer prognosis, but mitotic count was not. Ki-67/MiB-1, mitosin and pHH3 MF achieved statistical significance in the univariable analyses of both time to relapse (TTR) and overall survival (OS). Only mitosin remained significant in both multivariable analyses. pHH3 was significant in the multivariable analysis of OS but not of TTR. Clinical factors including age, extent of surgical resection and WHO performance status were also significantly correlated with survival. CONCLUSIONS: In conclusion, mitosin and pHH3 immunostaining have prognostic and diagnostic value in the clinical assessment of patients with infiltrative astrocytomas. The inclusion of proliferation markers in a layered diagnosis should be considered in the upcoming revision of the WHO classification system.

The diagnostic utility of reduced immunohistochemical expression of SMARCB1 in synovial sarcomas: a validation study.

Synovial sarcoma is a malignant mesenchymal neoplasm of uncertain histogenesis, characterized by a specific SS18-SSX fusion. The diagnosis of synovial sarcoma can be challenging based on morphology and conventional immunohistochemistry alone, and identification of the fusion gene by molecular genetics may be necessary for diagnosis. Several recent studies have demonstrated the diagnostic utility of the reduced expression of SMARCB1 in synovial sarcomas as measured using immunohistochemistry. Therefore, we undertook a validation study using synovial sarcomas and other spindle or round cell tumors that could enter differential diagnosis of monophasic or poorly differentiated synovial sarcomas. Among 36 synovial sarcomas that were successfully evaluated, the expression of SMARCB1 was diffusely reduced in 33 cases (92%) at variable degrees. In contrast, the expression of SMARCB1 was not reduced in any of the 93 evaluable non-synovial sarcoma tumors (5 thymomas, 5 sarcomatoid mesotheliomas, 10 schwannomas, 9 mesenchymal chondrosarcomas, 20 solitary fibrous tumors, 19 Ewing sarcomas, and 25 malignant peripheral nerve sheath tumors). A few schwannomas and malignant peripheral nerve sheath tumors showed mosaic or complete loss of SMARCB1 expression. Reduced expression of SMARCB1 immunoreactivity was therefore found to be highly sensitive and specific for synovial sarcoma, and can be useful for rapidly and accurately confirming the diagnosis of synovial sarcoma. This reduction in SMARCB1 expression likely reflects the BAF47 ejection mechanism of the SS18-SSX fusion product and can therefore be viewed as an indirect visualization of this fusion product.

Ellagic Acid-Changed Epigenome of Ribosomal Genes and Condensed RPA194-Positive Regions of Nucleoli in Tumour Cells.

We studied the effect of ellagic acid (EA) on the morphology of nucleoli and on the pattern of major proteins of the nucleolus. After EA treatment of HeLa cells, we observed condensation of nucleoli as documented by the pattern of argyrophilic nucleolar organizer regions (AgNORs). EA also induced condensation of RPA194-positive nucleolar regions, but no morphological changes were observed in nucleolar compartments positive for UBF1/2 proteins or fibrillarin. Studied morphological changes induced by EA were compared with the morphology of control, non-treated cells and with pronounced condensation of all nucleolar domains caused by actinomycin D (ACT-D) treatment. Similarly as ACT-D, but in a lesser extent, EA induced an increased number of 53BP1-positive DNA lesions. However, the main marker of DNA lesions, γH2AX, was not accumulated in body-like nuclear structures. An increased level of γH2AX was found by immunofluorescence and Western blots only after EA treatment. Intriguingly, the levels of fibrillarin, UBF1/2 and γH2AX were increased at the promoters of ribosomal genes, while 53BP1 and CARM1 levels were decreased by EA treatment at these genomic regions. In the entire genome, EA reduced H3R17 dimethylation. Taken together, ellagic acid is capable of significantly changing the nucleolar morphology and protein levels inside the nucleolus.

The DEK Oncoprotein Is a Critical Component of the EKLF/KLF1 Enhancer in Erythroid Cells.

Understanding how transcriptional regulators are themselves controlled is important in attaining a complete picture of the intracellular effects that follow signaling cascades during early development and cell-restricted differentiation. We have addressed this issue by focusing on the regulation of EKLF/KLF1, a zinc finger transcription factor that plays a necessary role in the global regulation of erythroid gene expression. Using biochemical affinity purification, we have identified the DEK oncoprotein as a critical factor that interacts with an essential upstream enhancer element of the EKLF promoter and exerts a positive effect on EKLF levels. This element also binds a core set of erythroid transcription factors, suggesting that DEK is part of a tissue-restricted enhanceosome that contains BMP4-dependent and -independent components. Together with local enrichment of properly coded histones and an open chromatin domain, optimal transcriptional activation of the EKLF locus can be established.

A SMARCB1-deficient vulvar neoplasm with prominent myxoid stroma: report of a case showing ERG and FLI1 expression.

In the vulvar region, epithelioid sarcoma (ES) is the most frequent SMARCB1-deficient neoplasm, followed by myoepithelial carcinoma (MC). Previous studies have demonstrated that some SMARCB1-deficient vulvar neoplasms cannot be classified as either ES or MC. Herein, we report of a 42-year-old woman with a SMARCB1-deficient neoplasm with prominent myxoid stroma in the vulva. It contained both epithelioid and spindled tumor cells, both of which showed vimentin and EMA expression. Although other markers useful for the differential diagnosis among SMARCB1-deficient tumors were negative, this tumor displayed characteristic expression of ERG and FLI1. As there are no reliable data regarding expression of ERG and FLI1 in MC, which are demonstrated to be often expressed in ES, further classification of cases such as the one reported here requires reliable data regarding their expression status in MC.

Genetic Inactivation of ATRX Leads to a Decrease in the Amount of Telomeric Cohesin and Level of Telomere Transcription in Human Glioma Cells.

Mutations in ATRX (alpha thalassemia/mental retardation syndrome X-linked), a chromatin-remodeling protein, are associated with the telomerase-independent ALT (alternative lengthening of telomeres) pathway of telomere maintenance in several types of cancer, including human gliomas. In telomerase-positive glioma cells, we found by immunofluorescence that ATRX localized not far from the chromosome ends but not exactly at the telomere termini. Chromatin immunoprecipitation (ChIP) experiments confirmed a subtelomeric localization for ATRX, yet short hairpin RNA (shRNA)-mediated genetic inactivation of ATRX failed to trigger the ALT pathway. Cohesin has been recently shown to be part of telomeric chromatin. Here, using ChIP, we showed that genetic inactivation of ATRX provoked diminution in the amount of cohesin in subtelomeric regions of telomerase-positive glioma cells. Inactivation of ATRX also led to diminution in the amount of TERRAs, noncoding RNAs resulting from transcription of telomeric DNA, as well as to a decrease in RNA polymerase II (RNAP II) levels at the telomeres. Our data suggest that ATRX might establish functional interactions with cohesin on telomeric chromatin in order to control TERRA levels and that one or the other or both of these events might be relevant to the triggering of the ALT pathway in cancer cells that exhibit genetic inactivation of ATRX.

Cystic synovial sarcoma of the pleura mimicking a cystic thymoma: a case report illustrating the role of decreased INI-1 expression in differential diagnosis.

Less than 40 cases of primary pleural synovial sarcoma (SS) have been reported to date. Furthermore, only three cases of cystic SS have been documented in the English literature, including cases originating from sites other than the pleura. Herein, we present an exceedingly rare case of cystic SS originating from the mediastinal side of the visceral pleura in an asymptomatic 47-year-old man, which was detected during a checkup. On contrast-enhanced computed tomography, distinguishing between cystic SS and cystic thymoma was difficult because the tumor was attached to the anterior mediastinum where the latter type of malignancy is more often detected. Histopathological examination showed tumor cells with spindled morphology showing hypercellularity and moderate nuclear atypia, with less than one mitotic figure per high-power field. As these features are associated with both monophasic fibrous SS and type A thymoma, more data was required to determine proper diagnosis, and therefore, immunohistochemistry was performed. Along with a conventional panel of markers, the SS-specific marker integrase interactor 1 (INI-1) was applied and found to be decreased; decreased expression of INI-1 is characteristic of SS. A diagnosis of SS was confirmed by detection of the SYT-SSX fusion gene via fluorescence in situ hybridization. Given the relatively common availability of INI-1 testing in departments of pathology, this protein would be helpful incorporated into the standard panel of markers for diagnosing SS.

Chromosomes Progress to Metaphase in Multiple Discrete Steps via Global Compaction/Expansion Cycles.

Mammalian mitotic chromosome morphogenesis was analyzed by 4D live-cell and snapshot deconvolution fluorescence imaging. Prophase chromosomes, whose organization was previously unknown, are revealed to comprise co-oriented sister linear loop arrays displayed along a single, peripheral, regularly kinked topoisomerase II/cohesin/condensin II axis. Thereafter, rather than smooth, progressive compaction as generally envisioned, progression to metaphase is a discontinuous process involving chromosome expansion as well as compaction. At late prophase, dependent on topoisomerase II and with concomitant cohesin release, chromosomes expand, axes split and straighten, and chromatin loops transit to a radial disposition around now-central axes. Finally, chromosomes globally compact, giving the metaphase state. These patterns are consistent with the hypothesis that the molecular events of chromosome morphogenesis are governed by accumulation and release of chromosome stress, created by chromatin compaction and expansion. Chromosome state could evolve analogously throughout the cell cycle.