Expression of leukotriene biosynthetic enzymes in tonsillar tissue of children with obstructive sleep apnea: a prospective nonrandomized study.

IMPORTANCE: Cysteinyl leukotrienes (CysLTs) potentially promote adenotonsillar hypertrophy in children with obstructive sleep apnea (OSA). Previous studies have identified CysLTs and their receptors in tonsillar tissue from children with OSA. OBJECTIVE: To demonstrate expression of the leukotriene biosynthetic enzymes 5-lipoxygenase (5-LO), 5-lipoxygenase activating protein (FLAP), leukotriene A(4) hydrolase (LTA(4)H), and leukotriene C(4) synthase (LTC(4)S) in T and B tonsillar lymphocytes from pediatric patients with OSA. It was hypothesized that children with OSA have greater expression of biosynthetic enzymes for CysLTs (5-LO, FLAP, and LTC(4)S) in their tonsillar tissue than do children with recurrent tonsillitis (RT), who were enrolled as controls. DESIGN, SETTING, AND PARTICIPANTS: This prospective, nonrandomized study was performed at a tertiary care university hospital on 13 children with OSA and adenotonsillar hypertrophy undergoing adenotonsillectomy and 12 children without OSA also undergoing tonsillectomy for RT. Tonsillar tissue from children with OSA or RT was examined for 5-LO, FLAP, LTA(4)H, and LTC(4)S expression under real time-quantitative polymerase chain reaction (RT-qPCR), flow cytometry (FC), and confocal laser scanning microscopy (CM). MAIN OUTCOMES AND MEASURES: Expression of biosynthetic enzymes for CysLTs (5-LO, FLAP, and LTC(4)S) was the main outcome measure. Patients with OSA and control patients with RT were compared for numbers of copies of 5-LO, FLAP, and LTC(4)S messenger RNA (by RT-qPCR) in T or B tonsillar lymphocytes and proportions of CD3(+) or CD19(+) tonsillar lymphocytes that expressed 5-LO, FLAP, and LTC(4)S (by FC). RESULTS: Messenger RNA for all 4 enzymes was detected in T and B lymphocytes from both study groups, and expression of all biosynthetic enzymes was demonstrated in participants with OSA and RT by FC. Patients with OSA differed from controls in the proportions (median [10th-90th percentile]) of LTC(4)S(+) CD3(+) T lymphocytes (23.31% [8.64%-50.07%] vs 10.81% [3.48%-23.32%], respectively) (P = .01) and LTC(4)S(+) CD19(+) B lymphocytes (20.66% [14.62%-65.77%] vs 12.53% [2.87%-36.64%], respectively) (P = .01) detected by FC. Immunoreactivity for the 4 enzymes was detected by CM in B lymphocytes of mantle zones and T lymphocytes of extrafollicular areas. CONCLUSIONS AND RELEVANCE: Leukotriene biosynthetic enzymes are expressed in tonsillar lymphocytes, and the previously reported detection of CysLTs in tonsillar tissue from children with OSA may be attributed to endogenous synthesis. Enhanced expression of LTC(4)S is a potential target for pharmacologic interventions in OSA.

The oncogenic JUNB/CD30 axis contributes to cell cycle deregulation in ALK+ anaplastic large cell lymphoma.

Anaplastic lymphoma kinase (ALK)+ anaplastic large cell lymphoma (ALCL) frequently carries the t(2;5)(p23;q35) resulting in expression of NPM1(NPM)-ALK oncogenic kinase. The latter is capable of activating ERK kinase, which upregulates JUNB expression through ETS1. JUNB, in turn, interacts with the TNFRSF8 (CD30) gene promoter and induces CD30 (TNFRSF8) overexpression. However, the role of CD30 overexpression in ALK+ ALCL oncogenesis remains unknown. Here we show that the JUNB gene is frequently amplified in ALK+ ALCL, suggesting gene amplification as an additional underlying mechanism for JUNB overexpression. Silencing of JUNB resulted in reduced cell growth and colony formation associated with decreased activator protein-1 activity and G1/S and G2/M cell cycle arrest. These effects were linked to decreased CD30 levels, downregulation of CCNA2 (Cyclin A), CCND2 (Cyclin D2) and CCND3 (Cyclin D3) and upregulation of cyclin-dependent kinase inhibitors CDKN2A (p14) and CDKN1A (p21), but not CDKN1B (p27). Similar cell cycle changes were observed following the knock-down of TNFRSF8 gene or blockade of its function using anti-CD30 antibodies, which were associated with upregulation of CDKN2A and CDKN1A, but not CDKN1B. These findings indicate that JUNB may partly operate through CD30 signalling. Silencing of JUNB also sensitized NPM1-ALCL+ cells to standard chemotherapeutic agents. Our findings uncover the oncogenic role of the JUNB/CD30 axis and its potential as therapeutic target in ALK+ ALCL.

Differential diagnosis between sclerosing adenosis and tubular carcinoma of the breast under transmission and scanning electron microscope.

The tubular carcinoma of the breast is an uncommon histological subtype of invasive breast cancer, which is generally associated with an excellent prognosis. Previous studies have demonstrated that this well differentiated variant is linked with a low incidence of lymph node involvement, a low rate of local recurrence and a high overall survival rate when compared to standard invasive ductal carcinoma. Due to its favorable prognosis, some studies have proposed that a diagnosis of tubular carcinoma might warrant less aggressive surgical or adjuvant treatment. Histologically, tubular carcinoma may mimic sclerosing adenoma or bluntduct adenosis. Its ductal nature appears well confirmed by the few ultrastructural studies of this mammary cancer. Tubular carcinoma should also be distinguished from microglandular adenosis, an uncommon form of sclerosing adenosis. The aim of this study is to prove that the ultrastructure results can give the correct diagnosis between tubular carcinoma and sclerosing adenosis.

The mode of lymphoblastoid cell death in response to gas phase cigarette smoke is dose-dependent.

BACKGROUND: Cigarette smoke (CS) is the main cause in the development of chronic obstructive pulmonary disease (COPD), the pathogenesis of which is related to an extended inflammatory response. In this study, we investigated the effect of low and high doses of gas phase cigarette smoke (GPS) on cultured lymphocyte progenitor cells, using techniques to assess cell viability and to elucidate whether cells die of apoptosis or necrosis upon exposure to different doses of GPS. METHODS: In our approach we utilised a newly-established system of exposure of cells to GPS that is highly controlled, accurately reproducible and simulates CS dosage and kinetics that take place in the smokers' lung. This system was used to study the mode of cell death upon exposure to GPS in conjunction with a range of techniques widely used for cell death studies such as Annexin V staining, activation of caspase -3, cytoplasmic release of cytochrome C, loss of mitochondrial membrane potential and DNA fragmentation. RESULTS: Low doses of GPS induced specific apoptotic indexes in CCRF-CEM cells. Specifically, cytochrome C release and cleaved caspase-3 were detected by immunofluorescence, upon treatment with 1-3 puffs GPS. At 4 h post-exposure, caspase-3 activation was observed in western blot analysis, showing a decreasing pattern as GPS doses increased. Concomitant with this behaviour, a dose-dependent change in Delta psi m depolarization was monitored by flow cytometry 2 h post-exposure, while at 4 h Delta psi m collapse was observed at the higher doses, indicative of a shift to a necrotic demise. A reduction in DNA fragmentation events produced by 5 puffs GPS as compared to those provoked by 3 puffs GPS, also pointed towards a necrotic response at the higher dose of GPS. CONCLUSION: Collectively, our results support that at low doses gas phase cigarette smoke induces apoptosis in cultured T-lymphocytes, whereas at high doses GPS leads to necrotic death, by-passing the characteristic stage of caspase-3 activation and, thus, the apoptotic route.