Secretion of plasminogen activator and its inhibitor by glomerular epithelial cells

Secretion of plasminogen activator and its inhibitor by glomerular epithelial cells. The effects of thrombin, interleukin-1 (IL-1), tumor necrosis factor (TNF) and γ-interferon (γ-IFN) on the release of plasminogen activator (PA) and inhibitor (PAI) were studied using cultivated human glomerular epithelial cells (GECs). Species of PAs and PAI secreted from the GECs were urokinase-type PA (u-PA) and tissue-type PA (t-PA), while the major species was a single chain u-PA in the amount of 28.6 ± 2.34 ng/105 cells for 24 hours (N = 4, mean ± SD), and PAI-1. The addition of increased concentrations of thrombin (0.1 to 31.6 U/ml) into confluent cultures enhanced the GECs to release u-PA, t-PA and PAI-1 in a dose- and time-dependent manner. The incubation of the GECs with 10 U/ml thrombin resulted in about a fourfold increase in the concentration of u-PA, threefold in t-PA and twofold in PAI-1. All thrombin effects, however, were suppressed by the simultaneous addition of cycloheximide, indicating that the enhancing effects of thrombin were due to an increase in the production of PAs and PAI-1, via protein synthesis. These thrombin effects appeared to be dependent upon the enzymatically active site of thrombin because DFP-thrombin had no effect. In the conditioned medium which was under continuous thrombin stimulation for 24 hours, no u-PA activity was detectable, even after the plasmin treatment, because a single chain u-PA was degraded by the thrombin. The stimulation of cultured GECs with thrombin only for the first three hours in 24 hour cultivation showed an apparent increase in the antigenic amount of u-PA. IL-1 enhanced the release of t-PA and PAI-1, and TNF did that of u-PA and t-PA, while γ-IFN showed no significant effects. These findings indicate that the GECs participate in the regulation of extracapillary fibrinolysis in the glomerular microenvironment, as being modulated by thrombin and two cytokines, IL-1 and TNF

Breast spindle cell carcinoma

Spindle cell carcinoma (SpCC) of the breast is quite a rare modality classified to the metaplastic carcinoma of the breast. Regarding its biological behavior and the prognosis of the patients with this rare tumor, it has been remaining controversial. We herein report an 88 year-old woman who had a huge bleeding tumor on the right breast. She was a high-aged woman with low activities of daily life, even with some suspicion of distant organ metastasis. While the tumor proved to drastically bleed due to the tumor disintegration, a right simple mastectomy was performed. According to the histopathologic examinations, sarcomatoid spindle cells with severe atypia were observed. By an immunohistochemical examination, the tumor had proved to express neither estrogen receptor, progesterone receptor nor HER2 receptor. Moreover an immunohistochemical expression of AE1/3 and CAM5.2, defining an epithelial neoplasm were observed in addition to an expression of vimentin. From these findings, this bleeding tumor was diagnosed as spindle cell carcinoma of the breast

Podoplanin in cancer cells is experimentally able to attenuate prolymphangiogenic and lymphogenous metastatic potentials of lung squamoid cancer cells

<p>Abstract</p> <p>Background</p> <p>Podoplanin, a mucin-like transmembrane glycoprotein, is reportedly expressed in a variety of malignant cells and is generally regarded as a factor for promoting tumor progression in conventional studies. By contrast, a clinicopathologically conflicting role for podoplanin, namely as a favorable prognostic factor for patients with lung/cervical squamous cell carcinoma (SCC), has recently been reported. Here, we investigated the role of podoplanin expressed in lung squamoid cancer cells (LSCCs) in experimental tumor progression.</p> <p>Results</p> <p>Using EBC-1 cells, a lung SCC cell line without podoplanin expression and with lymphogenous metastatic potential, stable transformants with or without an exogenous human <it>podoplanin </it>gene were established and applied to a mouse tumor implantation model. <it>In vivo </it>examinations revealed that exogenous podoplanin had no influence on tumor growth, whereas it significantly restrained axillary lymph node metastasis associated with the suppression of lymphangiogenesis but not angiogenesis and with the downregulation of EBC-1-derived VEGF-C but not other lymphangiogenesis-related factor mRNAs in implanted tumor tissue. <it>In vitro </it>examinations to clarify the mechanisms underlying the <it>in vivo </it>phenomena revealed that exogenous podoplanin significantly suppressed the expression of VEGF-C mRNA and of the protein, and also increased the level of phosphorylated c-jun N terminal kinase (JNK) in EBC-1 cells. The former effect of exogenous podoplanin was impaired by treatment with either JNK inhibitor sp600125 or podoplanin-siRNA, and the latter effect was impaired by treatment with podoplanin-siRNA, suggesting that podoplanin was able to activate JNK, thereby downregulating VEGF-C gene expression in LSCCs (podoplanin-JNK-VEGF-C axis). Furthermore, supporting evidence in regard to the axis present in LSCCs was obtained from similar experiments using H157 cells, another lung SCC cell line expressing endogenous podoplanin.</p> <p>Conclusions</p> <p>Our findings suggested that LSCC-associated podoplanin was functional and could attenuate the potential for lymph node metastasis, possibly based on the suppression of tumor lymphangiogenesis; thus, podoplanin in cancer cells may become a useful biomarker to measure the malignancy of lung SCC.</p

Adenoid Cystic Carcinoma of the Breast

An 85-year old woman who had a large tumor in the left breast came to our out-patient clinic. Computed tomography showed multiple lung tumors in addition to a huge tumor in the left breast. A needle biopsy brought about a histological diagnosis of ductal carcinoma. A simple mastectomy was performed and a histological examination using the resected specimen demonstrated a coexistence of an adenoid structure and a false ductal structure according the histologic characteristics of adenoid cystic carcinoma, which is quite rare among breast tumors

Important Role of Tissue Angiotensin-converting Enzyme Activity in the Pathogenesis of Coronary Vascular and Myocardial Structural Changes Induced by Long-Term Blockade of Nitric Oxide Synthesis in Rats

The long-term administration of N �-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthesis, produces coronary vascular remodeling and myocardial hypertrophy in animals. This study used a rat model to investigate the role of angiotensin I converting enzyme (ACE) in the pathogenesis of such changes. We studied the following groups, all of which received drug treatment in their drinking water: untreated controls, and those administered L-NAME, L-NAME, and an ACE inhibitor (ACEI), and L-NAME and hydralazine. Cardiovascular structural changes and tissue ACE activities were evaluated after the first, fourth, and eighth week of treatment. In rats treated with L-NAME alone, vascular remodeling was evident at the fourth and eighth week, and myocardial hypertrophy was present at the eighth week of treatment. The vascular and myocardial remodeling were characterized by increased tissue ACE activities and immunodetectable ACE in those tissues. These changes were markedly reduced by ACEI, but not by hydralazine treatment. Increased local ACE expression may thus be important in the pathogenesis of cardiovascular remodeling in this model. (J. Clin. Invest. 1997. 99: 278–287.) Key words: angiotensin converting enzyme inhibitor • renin-angiotensin system • nitric oxide • left ventricular hypertrophy • coronary circulatio