Novel mechanism for OSM-promoted extracellular matrix remodeling in breast cancer: LOXL2 upregulation and subsequent ECM alignment.

BACKGROUND: Invasive ductal carcinoma (IDC) is a serious problem for patients as it metastasizes, decreasing 5-year patient survival from > 95 to ~ 27%. The breast tumor microenvironment (TME) is often saturated with proinflammatory cytokines, such as oncostatin M (OSM), which promote epithelial-to-mesenchymal transitions (EMT) in IDC and increased metastasis. The extracellular matrix (ECM) also plays an important role in promoting invasive and metastatic potential of IDC. Specifically, the reorganization and alignment of collagen fibers in stromal ECM leads to directed tumor cell motility, which promotes metastasis. Lysyl oxidase like-2 (LOXL2) catalyzes ECM remodeling by crosslinking of collagen I in the ECM. We propose a novel mechanism whereby OSM induces LOXL2 expression, mediating stromal ECM remodeling of the breast TME. METHODS: Bioinformatics was utilized to determine survival and gene correlation in patients. IDC cell lines were treated with OSM (also IL-6, LIF, and IL-1ß) and analyzed for LOXL2 expression by qRT-PCR and immunolabelling techniques. Collagen I contraction assays, 3D invasion assays, and confocal microscopy were performed with and without LOXL2 inhibition to determine the impact of OSM-induced LOXL2 on the ECM. RESULTS: Our studies demonstrate that IDC patients with high LOXL2 and OSM co-expression had worse rates of metastasis-free survival than those with high levels of either, individually, and LOXL2 expression is positively correlated to OSM/OSM receptor (OSMR) expression in IDC patients. Furthermore, human IDC cells treated with OSM resulted in a significant increase in LOXL2 mRNA, which led to upregulated protein expression of secreted, glycosylated, and enzymatically active LOXL2. The expression of LOXL2 in IDC cells did not affect OSM-promoted EMT, and LOXL2 was localized to the cytoplasm and/or secreted. OSM-induced LOXL2 promoted an increase in ECM collagen I fiber crosslinking, which led to significant fiber alignment between cells and increased IDC cell invasion. CONCLUSIONS: Aligned collagen fibers in the ECM provide pathways for tumor cells to migrate more easily through the stroma to nearby vasculature and tissue. These results provide a new paradigm through which proinflammatory cytokine OSM promotes tumor progression. Understanding the nuances in IDC metastasis will lead to better potential therapeutics to combat against the possibility.

The Slanic-Prahova (ROMANIA) underground low-background radiation laboratory.

A low-background radiation laboratory was constructed and fully commissioned in 2006 in the former Unirea (Slanic-Prahova) salt mine at 208 m below surface (estimated to 560 m water equivalent). Preliminary measurements showed a global reduction of the absorbed dose due to natural factors of about 39 times compared to level on the surface, reaching inside the mine 1.17+/-0.14 nGy/h. The total gamma background spectrum between 40 KeV and 3 MeV was 100 times smaller at laboratory level with respect to the same spectrum recorder at surface, in open field. All these experimental facts recommend the Slanic-Prahova low-background radiation laboratory, at present time fully operational, as very suitable for various measurements needing a low background.

Decreased LRIG1 in fulvestrant-treated luminal breast cancer cells permits ErbB3 upregulation and increased growth.

ErbB3, a member of the ErbB family of receptor tyrosine kinases, is a potent activator of phosphatidyl inositol-3 kinase (PI3K) and mammalian target of rapamycin (mTOR) signaling, driving tumor cell survival and therapeutic resistance in breast cancers. In luminal breast cancers, ErbB3 upregulation following treatment with the antiestrogen fulvestrant enhances PI3K/mTOR-mediated cell survival. However, the mechanism by which ErbB3 is upregulated in fulvestrant-treated cells is unknown. We found that ErbB3 protein levels and cell surface presentation were increased following fulvestrant treatment, focusing our attention on proteins that regulate ErbB3 at the cell surface, including Nrdp1, NEDD4 and LRIG1. Among these, only LRIG1 correlated positively with ERα, but inversely with ErbB3 in clinical breast cancer data sets. LRIG1, an estrogen-inducible ErbB downregulator, was decreased in a panel of fulvestrant-treated luminal breast cancer cells. Ectopic LRIG1 expression from an estrogen-independent promoter uncoupled LRIG1 from estrogen regulation, thus sustaining LRIG1 and maintaining low ErbB3 levels in fulvestrant-treated cells. An LRIG1 mutant lacking the ErbB3 interaction motif was insufficient to downregulate ErbB3. Importantly, LRIG1 overexpression improved fulvestrant-mediated growth inhibition, whereas cells expressing the LRIG1 mutant were poorly sensitive to fulvestrant, despite effective ERα downregulation. Consistent with these results, LRIG1 expression correlated positively with increased disease-free survival in antiestrogen-treated breast cancer patients. These data suggest that ERα-dependent expression of LRIG1 dampens ErbB3 signaling in luminal breast cancer cells, and by blocking ERα activity with fulvestrant, LRIG1 is decreased thus permitting ErbB3 accumulation, enhanced ErbB3 signaling to cell survival pathways and blunting therapeutic response to fulvestrant.

LRIG1 opposes epithelial-to-mesenchymal transition and inhibits invasion of basal-like breast cancer cells.

LRIG1 (leucine-rich repeat and immunoglobulin-like domain containing), a member of the LRIG family of transmembrane leucine-rich repeat-containing proteins, is a negative regulator of receptor tyrosine kinase signaling and a tumor suppressor. LRIG1 expression is broadly decreased in human cancer and in breast cancer and low expression of LRIG1 has been linked to decreased relapse-free survival. Recently, low expression of LRIG1 was revealed to be an independent risk factor for breast cancer metastasis and death. These findings suggest that LRIG1 may oppose breast cancer cell motility and invasion, cellular processes that are fundamental to metastasis. However, very little is known of LRIG1 function in this regard. In this study, we demonstrate that LRIG1 is downregulated during epithelial-to-mesenchymal transition (EMT) of human mammary epithelial cells, suggesting that LRIG1 expression may represent a barrier to EMT. Indeed, depletion of endogenous LRIG1 in human mammary epithelial cells expands the stem cell population, augments mammosphere formation and accelerates EMT. Conversely, expression of LRIG1 in highly invasive Basal B breast cancer cells provokes a mesenchymal-to-epithelial transition accompanied by a dramatic suppression of tumorsphere formation and a striking loss of invasive growth in three-dimensional culture. LRIG1 expression perturbs multiple signaling pathways and represses markers and effectors of the mesenchymal state. Furthermore, LRIG1 expression in MDA-MB-231 breast cancer cells significantly slows their growth as tumors, providing the first in vivo evidence that LRIG1 functions as a growth suppressor in breast cancer.

[Planimetric measurement of the regurgitant orifice area using tridimensional transoesophageal echocardiography for aortic regurgitation, reproducibility and feasibility]. / Validation de la reproductibilité de la mesure de la surface de l'orifice régurgitant par planimétrie dans l'insuffisance aortique : une étude préliminaire d'échocardiographie trans-œsophagienne tridimensionnelle.

BACKGROUND: Aortic regurgitation is mainly evaluated by trans-thoracic echocardiography using multi-parametric qualitative and semi quantitative tools. All those parameters can fail to meet expectations, resulting in an imperfect diagnostic reliability and assessment of aortic regurgitation severity can be challenging. OBJECTIVES: We sought to evaluate feasibility and intra- and inter-observer reproducibility of aortic regurgitant orifice area measured by planimetry with tridimensional trans-esophageal echocardiography on patients with at least grade 2/4 aortic regurgitation. PATIENTS AND METHODS: Consecutive patients with at least grade 2/4 aortic regurgitation measured by trans-thoracic echocardiography and referred for trans-esophageal echocardiography for any reason were included. Planimetric reconstructions of regurgitant orifice area were studied and reproducibility indexes between senior and junior observers were calculated. RESULTS: Twenty-three patients were included in this study. Intra- and inter-observer reproducibility were excellent with an ICC of 0.95 [0.88-0.98], P<0.0001 and 0.91 [0.79-0.96], P<0.0001, respectively. Mean length of the measurement was 6.6±0.9min [CI95% 6.23-7.01]. CONCLUSION: Planimetric measurement of the aortic regurgitant orifice using tridimensional trans-esophageal echocardiography seems to be feasible and has great intra- and inter-observer reproducibility. Reconstruction durations were compatible with a daily use. There is a need now to investigate the reliability of this measurement as compared with the reference technique.

Dehalogenation of aromatic halides using metallic calcium in ethanol.

The scope and limitations of the dehalogenation of aromatic halides 1 and 4a-p using metallic calcium in ethanol at room temperature were revealed. The cleavage of the carbon-chlorine bond on the aromatic ring bearing electron-donating group was difficult compared to the one bearing electron-withdrawing group. Moreover, we applied this method to the dechlorination of polychlorinated biphenyls (PCBs) in transformer oil. It was also found that the dechlorination took place easily under mild conditions. The existence of PCBs residue in the reaction at room temperature was less than 0.04% according to the GC-MS analysis. The chlorine was identified as calcium chloride.

Clinical manifestations in the West Nile virus outbreak.

During the summer of 1996 an unusual clustering of meningoencephalitis cases was recorded in the Capital City, Bucharest, and in some areas from South-East Romania. After an initial suspicion of an enteroviral etiology was discarded, the West Nile etiology was confirmed by specific antibodies demonstration through hemagglutination-inhibition and ELISA tests. This study included 251 patients with the diagnoses of West Nile acute encephalitis (166 cases), acute meningitis (57 cases) and acute febrile disease (33 cases). The patients' age ranged from 1 to 89 years (mean 51.1 years). The most frequent clinical manifestations were: fever (95.7% of cases), cephalalgia (92.6%), stiffness of the neck (89.1%), vomiting (62.5%), marked asthenia (46.5%), myalgia (28.9%). In addition, patients with encephalitis exhibited: alteration of consciousness (89.2% of cases), tremor of extremities (40.4%), ataxia (44%), paralysis (15.1%). The fatality rate was 15.1% in acute encephalitis, 1.8% in acute meningitis and 0% in the acute febrile disease.