Cripto‐1 Expression in Glioblastoma Multiforme

Human glioblastoma multiforme (GBM) is an aggressive cancer with a very poor prognosis. Cripto‐1 (CR‐1) has a key regulatory role in embryogenesis, while in adult tissue re‐expression of CR‐1 has been correlated to malignant progression in solid cancers of non‐neuronal origin. As CR‐1 expression has yet to be described in cerebral cancer and CR‐1 is regulated by signaling pathways dysregulated in GBM, we aimed to investigate CR‐1 in the context of expression in GBM. The study was performed using enzyme‐linked immunosorbent assay (ELISA), Western blotting, polymerase chain reaction (PCR) and immunohistochemistry to analyze the blood and tissue from 28 GBM and 4 low‐grade glioma patients. Within the patient cohort, we found high CR‐1 protein levels in blood plasma to significantly correlate with a shorter overall survival. We identified CR‐1 in different areas of GBM tissue, including perivascular tumor cells, and in endothelial cells. Collectively, our data suggest that CR‐1 could be a prognostic biomarker for GBM with the potential of being a therapeutic target.     

Increased brain water content in pseudotumour cerebri measured by magnetic resonance imaging of brain water self diffusion

Brain water self diffusion was investigated by magnetic resonance scanning in 7 patients fulfilling conventional diagnostic criteria for pseudotumour cerebri. Quantitative diffusion measurements were obtained using single spin echo pulse sequences with pulsed magnetic field gradients of different magnitude. In all patients the diffusion images showed an increased diffusion in various brain regions when compared with the diffusion coefficients for corresponding regions in healthy subjects. In 3 pseudotumour patients the increased self diffusion was localized to the periventricular regions, while 4 patients had increased diffusion in the whole brain. The findings indicate the presence of increased brain water content both intra- and extracellularly suggesting that patients with pseudotumour have two defects of pathogenetical significance: intracellular water accumulation and increased resistance to cerebrospinal fluid (CSF) outflow leading to an interstitial oedema.     

Mitral annulus motion compared with wall motion scoring index in the assessment of left ventricular ejection fraction.

The biplane disc summation method is the recommended echocardiographic procedure to determine left ventricular (LV) ejection fraction (EF). Assessment of mitral annulus motion (MAM) or wall motion scoring index (WMI) has been reported to be less dependent on image quality compared with the recommended method, and proposed as a surrogate to the disc summation method in calculation of LVEF. We aimed to compare MAM and WMI in the echocardiographic assessment of LVEF. In a randomly selected population-based sample of 75-year-old men and women in sinus rhythm (n = 409) MAM, as measured by M-mode, was compared with WMI, calculated as the mean value of wall motion scoring in 9 LV segments. LVEF, as measured by the biplane disc summation method was used as reference. The limits of agreement (mean difference +/- 1.96 SD) between LVEF and corresponding MAM values were -18 to +13 LVEF%, and between LVEF and corresponding WMI values were -12 to +13 LVEF%. The areas under the receiver operating characteristic curves for MAM and WMI to predict a LVEF < 50% were 0.892 and 0.998, respectively (95% confidence interval of the difference 0.062-0.149). The corresponding areas for MAM and WMI to predict a LVEF < 40% were 0.955 and 0.998, respectively (95% confidence interval of the difference 0.017-0.069). In conclusion, the ability of WMI to estimate LVEF was more favorable than MAM in this population-based sample of 75-year-old participants. The findings suggest that the WMI is preferable to MAM in estimating LVEF.     

In vivo evaluation of PEGylated <Superscript>64</Superscript>Cu-liposomes with theranostic and radiotherapeutic potential using micro PET/CT

Purpose

The objective of this study was to evaluate the potential of PEGylated ⁶⁴Cu-liposomes in clinical diagnostic positron emission tomography (PET) imaging and PEGylated ¹⁷⁷Lu-liposomes in internal tumor radiotherapy through in vivo characterization and dosimetric analysis in a human xenograft mouse model.

Methods

Liposomes with 5 and 10 mol% PEG were characterized with respect to size, charge, and ⁶⁴Cu- and ¹⁷⁷Lu-loading efficiency. The tumor imaging potential of ⁶⁴Cu-loaded liposomes was evaluated in terms of in vivo biodistribution, tumor accumulation and tumor-to-muscle (T/M) ratios, using PET imaging. The potential of PEGylated liposomes for diagnostic and therapeutic applications was further evaluated through dosimetry analysis using OLINDA/EXM software. The ⁶⁴Cu-liposomes were used as biological surrogates to estimate the organ and tumor kinetics of ¹⁷⁷Lu-liposomes.

Results

High remote loading efficiency (>95 %) was obtained for both ⁶⁴Cu and ¹⁷⁷Lu radionuclides with PEGylated liposomes, and essentially no leakage of the encapsulated radionuclide was observed upon storage and after serum incubation for 24 h at 37 °C. The 10 mol% PEG liposomes showed higher tumor accumulation (6.2?±?0.2 %ID/g) than the 5 mol% PEG liposomes, as evaluated by PET imaging. The dosimetry analysis of the ⁶⁴Cu-liposomes estimated an acceptable total effective dose of 3.3·10^?2 mSv/MBq for diagnostic imaging in patients. A high absorbed tumor dose (114 mGy/MBq) was estimated for the potential radiotherapeutic ¹⁷⁷Lu-liposomes.

Conclusion

The overall preclinical profile of PEGylated ⁶⁴Cu-liposomes showed high potential as a new PET theranostic tracer for imaging in humans. Dosimetry results predicted that initial administered activity of 200 MBq of ⁶⁴Cu-liposomes should be acceptable in patients. Work is in progress to validate the utility of PEGylated ⁶⁴Cu-liposomes in a clinical research programme. The high absorbed tumor dose (114 mGy/MBq) estimated for ¹⁷⁷Lu-liposomes and the preliminary dosimetric studies justify further therapeutic and dosimetry investigation of ¹⁷⁷Lu-liposomes in animals before potential testing in man.

     

Expression of bcr-abl abrogates factor-dependent growth of human hematopoietic M07E cells by an autocrine mechanism

The introduction of a retrovirus vector expressing p210bcr-abl (P210) into the human factor-dependent cell line M07E resulted in the rapid outgrowth of factor-independent cells. Early after infection, four factor-independent clones were isolated and analyzed in greater detail along with mass populations obtained from separate infections. High levels of P210 tyrosine kinase activity were measured in the factor- independent cells. The mass populations and three of the four clones remained responsive to exogenous growth factors. Concentrated conditioned media isolated from the factor-independent populations and from all clones contained biologically active granulocyte-macrophage colony-stimulating factor (GM-CSF); interleukin-3 (IL-3) was detected at low levels in the mass population and in two of the clones. Neutralizing antibodies to IL-3, GM-CSF, and mast cell growth factor inhibited proliferation of the factor responsive clones by 60% to 90%. These results indicate that the growth autonomy of the P210-expressing M07E cells was acquired via an autocrine mechanism. In addition to factor-independent growth, P210-expressing M07E cells readily acquired a more mature megakaryocytic phenotype compared with control M07E cells. These data provide experimental evidence that expression of P210 tyrosine kinase in human hematopoietic cells induced growth factor secretion resulting in a pleiotropic effect on growth factor dependence and differentiation.