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Background The Y-box binding protein 1 (YB-1) possesses pleiotropic functions through its interactions with various cellular proteins, and its high expression levels make it a potential useful prognostic biomarker for cancer cells. Eukaryotic DNA topoisomerases, such as DNA topoisomerase 1 (TOPO1) and DNA topoisomerase 2 (TOPO2), are the essential DNA metabolism regulators that usually overexpressed in cancer cells, and multiple proteins have been reported to regulate the enzyme activity and the clinical efficacy of their inhibitors. The present study unraveled the interaction of YB-1 with TOPO1, and further investigated the related function and potential mechanisms during the interaction. Methods The direct association of TOPO1 with specific domain of YB-1 was explored by coimmunoprecipitation and GST pull-down assays. The interaction function was further clarified by DNA relaxation assays, co-immunoprecipitation and WST-8 assays with in vitro gain- and loss- of function models. Results We found that YB-1 interacts directly with TOPO1 (but not with TOPO2) and promotes TOPO1 catalytic activity. Interactions between YB-1 and TOPO1 increased when cancer cells were treated with the TOPO1 inhibitor, camptothecin (CPT), but not with the TOPO2 inhibitor, adriamycin (ADM). Furthermore, we found that the interaction is prevented by pretreatment with the antioxidant agent, N-acetyl cysteine, and that YB-1 downregulation renders cells resistant to CPT. Conclusions Our findings suggest that nuclear YB-1 serves as an intracellular promoter of TOPO1 catalytic activity that enhances CPT sensitivity through its direct interaction with TOPO1. [ABSTRACT FROM AUTHOR]

Background: Increased expression of nitric oxide synthase (NOS) and an increase in plasma nitrite plus nitrate (NOx) have been reported in patients with pulmonary fibrosis, suggesting that nitric oxide (NO) plays an important role in its development. However, the roles of the entire NO and NOS system in the pathogenesis of pulmonary fibrosis still remain to be fully elucidated. The aim of the present study is to clarify the roles of NO and the NOS system in pulmonary fibrosis by using the mice lacking all three NOS isoforms. Methods: Wild-type, single NOS knockout and triple NOS knockout (n/i/eNOS-/-) mice were administered bleomycin (BLM) intraperitoneally at a dose of 8.0 mg/kg/day for 10 consecutive days. Two weeks after the end of the procedure, the fibrotic and inflammatory changes of the lung were evaluated. In addition, we evaluated the effects of long-term treatment with isosorbide dinitrate, a NO donor, on the n/i/eNOS-/- mice with BLM-induced pulmonary fibrosis. Results: The histopathological findings, collagen content and the total cell number in bronchoalveolar lavage fluid were the most severe/highest in the n/i/eNOS-/- mice. Long-term treatment with the supplemental NO donor in n/i/eNOS-/- mice significantly prevented the progression of the histopathological findings and the increase of the collagen content in the lungs. Conclusions: These results provide the first direct evidence that a lack of all three NOS isoforms led to a deterioration of pulmonary fibrosis in a BLM-treated murine model. We speculate that the entire endogenous NO and NOS system plays an important protective role in the pathogenesis of pulmonary fibrosis. [ABSTRACT FROM AUTHOR]

A mammary nodular lesion was recognized one month before the surgery in the right upper breast of a 55-year-old female. The fine needle aspiration cytology specimens contained many individual bizarre, multi-nucleated, and/or giant cells having hyperchromatic pleomorphic nuclei, prominent nucleoli, and relatively abundant cytoplasm, admixed with numerous mitotic figures in a hemorrhagic or inflammatory background. A small amount of sheet-like or three-dimensional clusters of malignant cells coexisted. We first interpreted it as high-grade malignancy, such as invasive carcinoma, not otherwise specified. A right breast-conserving surgery was performed, and gross examination revealed a cystic cavity-formed and solid tumor lesion, measuring 35 × 35 × 25 mm and looking gray-yellowish to -whitish. On microscopic examination, the tumor was composed of a diffuse proliferation of highly atypical cells devoid of adhesive characteristics, including many multi-nucleated giant bizarre cells, in a haphazard fashion with stromal invasion, alternating with sarcomatoid features of spindle tumor cells. The cystic cavity was surrounded by hemorrhagic and inflammatory granulation tissue and lined by mostly denuded but atypical tumor cells or bland-looking flattened epithelial cells. Immunohistochemically, these tumor cells are specifically positive for all epithelial markers. Therefore, we made a conclusive diagnosis of pleomorphic carcinoma of the breast with cyst formation. We should be aware that, owing to its characteristic findings, cytopathologists can diagnose correctly, based on careful cytological examination of adequate samplings. [ABSTRACT FROM AUTHOR]

Abstract: A history of a recent rapid increase in long-standing swelling mass was presented in the right parotid gland of an 85-year-old male. The inadequate cytologic specimens contained few small clusters of three-dimensional malignant epithelial cells having hyperchromatic pleomorphic nuclei and prominent nucleoli, adjacent to a cluster of benign monomorphic myoepithelial cells. We first interpreted it merely as an adenocarcinoma, not otherwise specified. A radical parotidectomy was performed, and gross examination revealed an encapsulated and firm tumor lesion, looking grayish-blue to yellowish-white, focally associated with extracapsular invasion. On microscopic examination, the tumor was predominantly composed of a proliferation of highly atypical epithelial cells having abundant eosinophilic cytoplasm, often arranged in a Roman-bridge appearance with foci of comedo necrosis, alternating with extensive infiltration to adjacent stroma in a trabecular or alveolar fashion with severe vessel permeation. Within the background of pleomorphic adenoma, the carcinoma cells sometimes replaced ductal luminal cells while retaining an intact-like myoepithelial layer. Therefore, we finally made a diagnosis of invasive salivary duct carcinoma ex pleomorphic adenoma. We should be aware that owing to its characteristic features, cytopathologists might be able to determine correct diagnosis, based on multiple and adequate samplings. [ABSTRACT FROM AUTHOR]

A 78-year-old Japanese male noticed a difficulty in the beginning of standing up, followed by 7a progressive numbness of extremities with pain, Bell's palsy, dysarthria, and difficulty in swallowing. A clinician had suspected cancer of unknown primary origin, accompanied by the diverse and elusive neurological symptoms, likely presenting as painful mononeuropathy simplex and cranial neuropathy. He developed dysbasia over weeks and died 1 month after the symptom onset. At autopsy, an ill-defined large and soft tumor mass in the right lobe of the liver with direct invasion into the right adrenal gland was observed. The left adrenal gland or right iliopsoas muscle was also involved. Microscopic findings showed a monotonous proliferation of medium-sized to large atypical lymphoid cells, which were diffusely positive for CD20 in immunohistochemistry, consistent with diffuse large B-cell lymphoma (DLBL). Furthermore, the lymphoma cells aggressively infiltrated endoneurial and subperineurial spaces not only in the peripheral nerves and plexuses, but partly in the spinal nerve roots, and intravascular spaces in various tissues. Therefore, systemic lymphoma (DLBL) complicated with neurolymphomatosis (NL) and intravascular lymphoma (IVL) was diagnosed. Very early diagnosis and treatment are necessary for the NL patients with poor prognosis. [ABSTRACT FROM AUTHOR]