Co-targeting the IGF system and HIF-1 inhibits migration and invasion by (triple-negative) breast cancer cells.

BACKGROUND: Metastatic triple-negative breast cancer is mostly incurable, due to lack of suitable drug targets. The insulin-like growth factor (IGF) system could provide such a target, and IGF-1 receptor (IGF-1R)-directed agents are already available, but seem unable to control all the complexities of the system, including crosstalk with hypoxia-inducible pathways. METHODS: Migration of triple-negative MDA-231 breast cancer cells and its modulation by IGFs, the IGF-1R inhibitor NVP-AEW541 and the IGF-2-sequestering monoclonal antibody MAB292 were assessed by the scratch wound healing and Boyden chamber assays; the effect of topotecan (inhibiting hypoxia-inducible factor-1 (HIF-1)) under hypoxia was also evaluated. Constitutive as well as drug-modulated levels of components of the IGF and HIF-1 pathways were evaluated by western blotting and qPCR. RESULTS: IGF-induced migration of MDA-231 cells was not abrogated by the IGF-1R inhibitor NVP-AEW541, whereas IGF-2 sequestration by MAB292 significantly reduced cell migration. Under hypoxia, topotecan was also effective, likely by reducing HIF-1-induced IGF-2 release. Simultaneous targeting of IGF-1R and IGF-2 or HIF-1 completely abolished cell migration. CONCLUSIONS: IR activation may account for the failure of NVP-AEW541 to suppress MDA-231 cell migration. Ligand-targeting compounds, or co-inhibition of the IGF and HIF-1 systems, may prevent activation of compensatory signalling, thereby providing a valuable addition to IGF-1R inhibitor-based therapies.

Predictive accuracy of triage nurses evaluation in risk stratification of syncope in the emergency department.

BACKGROUND: Syncope is a common clinical problem that accounts for 1-3% of all emergency department (ED) visits. Its prognosis is extremely variable with a 1-year mortality that may reach 30%. There are no available data about the accuracy of nursing triage in identifying high-risk syncope. The aim of our study was to evaluate the predictive accuracy of nursing triage in identifying high-risk syncope. METHODS: We conducted a retrospective study on 678 consecutive patients who presented with syncope at four EDs. For each patient, nursing triage, comorbidities, clinical features and adverse events that occurred both in the ED and at 10-day follow-up were assessed. Adverse events included death, readmission to ED, need for major therapeutic procedures, cardiopulmonary resuscitation, intensive care unit admittance, acute antiarrhythmic therapy and major causes of syncope identified during the ED evaluation. Predictive accuracy of nursing triage was evaluated. RESULTS: We observed a total of 55 (8.1%) adverse events. Eight of them (9.4%) occurred among the 85 patients who were identified as high priority by nursing triage. Sensitivity (Sn) and specificity (Sp) of urgent nursing triage in identifying adverse outcomes in the ED (19 patients) were 21% (95% CI 3% to 39%) and 88% (95% CI 85% to 90%), while the positive likelihood ratio (LR+) and negative likelihood ratio (LR-) were 1.7 and 0.9, respectively. Sn and Sp for 10-day adverse events were 15% (95% CI 5% to 24%) and 88% (95% CI 85% to 90%), respectively, with a LR+ of 1.18 and a LR- of 0.98. CONCLUSIONS: Nursing triage was characterised by a low predictive accuracy in identifying high-risk individuals.

Meiotic abnormalities in patients bearing complete AZFc deletion of Y chromosome.

BACKGROUND: We studied meiosis in three infertile patients presenting complete AZFc microdeletion and three controls. METHODS: Primary spermatocytes were immunolabeled with SCP3, BRCA1 and gammaH2AX. We quantified the leptotene, zygotene and pachytene stages, and pachytene abnormalities: asynapsis and fragmented and dotted synaptonemal complexes (SCs). RESULTS: SCP3 level was significantly higher in leptotene and zygotene (bouquet) stages in patients, suggesting AZFc may have a direct effect on early prophase. SCs were abnormal in 77.3% of pachytene nuclei of patients versus 30.8% of controls. The two groups differed significantly (P < 0.001) in asynapsed nuclei, fragmented SC and dotted SCs. In patients, asynapsis were short and limited to a few bivalents. Staging of pachytene nuclei based on the morphology of the XY pair with BRCA1 revealed a prevalence of early pachytene substages (70.7%) in patients. H2AX was normally phosphorylated. CONCLUSIONS: In the absence of the AZFc region, the transient zygotene stage is extended, and chromosome condensation is reduced. The low level of limited asynapsis, the normal H2AX staining and the incomplete loss of germ cells at the pachytene checkpoint indicate that the AZFc region is not critical for meiotic recombination. We suggest that the pachytene phenotype develops secondarily to a primary defect that influences meiosis.

Influence of t-pA and u-PA on adipose tissue development in a murine model of diet-induced obesity.

To investigate the potential role of tissue-type plasminogen activator (t-PA) or urokinase-type plasminogen activator (u-PA) in development of adipose tissue, we have used a nutritionally induced obesity model in t-PA (t-PA-/-) and u-PA (u-PA-/-) deficient mice. Five week old male wild-type (WT), t-PA-/- or u-PA-/- mice (n = 9 to 16) were fed a high fat diet (HFD, 42% fat). After 16 weeks of HFD, the body weight of t-PA-/- mice was significantly higher than that of WT mice (48 +/- 1.1 g vs. 39 +/- 2.2 g, p = 0.004). The total weight of the isolated subcutaneous (sc) fat deposit was higher in t-PA-/- than in WT mice (2.4 +/- 0.22 g vs. 1.2 +/- 0.29 g, p = 0.002). accompanied with higher adipocyte diameters (80 +/- 1.7 microm vs. 61 +/- 4.7 microm, p < 0.01). These differences were not observed in the intra-abdominal fat deposit. The number of stroma cells in both adipose tissue territories was increased in t-PA-/- as compared to WT mice (2.0 +/- 0.13 vs. 1.5 +/- 0.10, p = 0.2 and 3.0 +/- 0.17 vs 1.6 +/- 0.17, p = 0.0001, stroma cells/adipocytes in sc and intra-abdominal tissue, respectively), partly as a result of an increased number of endothelial cells (192 +/- 9 vs. 154 +/-18, p = 0.06 and 108 +/- 13 vs. 69 +/- 8, p = 0.04 CD31 stained/adipocyte area). In contrast the weight gain and adipose tissue development in u-PA-/- mice was not different from that in WT mice. These data suggest that t-PA but not u-PA plays a role in adipose tissue development.