MHC nonrestricted cytotoxic T cell clones with selective specificity from patients with transitional cell carcinoma (TCC) of the urinary bladder

Summary Lymphocytes from patients with transitional cell carcinoma (TCC) of the urinary bladder are more cytotoxic to bladder tumor cells than to a variety of control cells. This disease-related cytotoxicity has previously been shown to involve several mechanisms and different types of effector cells. To analyze further the nature of the effector cells operative in this system, peripheral blood lymphocytes from eight TCC patients were stimulated in vitro with TCC extract and cultured in the presence of interleukin 2 and allogeneic feeder cells. When tested for cytotoxicity in vitro on a target cell panel including both adherent and nonadherent cell lines, the lymphocytes killed a broad spectrum of targets in a major histocompatibility complex (MHC)-unrestricted fashion. When cloned by limiting dilution, clones were obtained which displayed a more restricted pattern of target cell killing. Some of the clones were highly but not exclusively selective for TCC-derived target cells. Phenotypically, these cells resembled mature T cells of CTL-type (CD8⁺/CD4^–). They also expressed the CD3/5 T cell antigen receptor complex but target cell killing was not MHC-restricted. The results of various inhibition experiments suggested that the CD3/TCR complex was involved in the cytotoxicity exhibited by these effector cells. However, its precise role in target cell recognition and the identification of the tumor cell structures recognised by the effector cells require further studies.     

Reversal of sexual impotence in male patients with chronic obstructive pulmonary disease and hypoxemia with long term oxygen therapy

Erectile impotence is commonly encountered in male patients with respiratory failure and hypoxia. In this study, 42% of the patients experienced reversal of sexual impotence during long term oxygen therapy (LTOT). We examine the association between sexual impotence, gonadal axis hormones, hypoxia, and oxygen therapy. Nineteen sexually impotent male patients eligible for LTOT (pO₂ < 7.3 kPa during stable disease) and with sexual impotence received oxygen therapy for 1 month (n = 12) or 24 h (n = 7). pO₂, LH, FSH, testosterone, and SHBG (sex hormone binding globulin) were monitored. Five of 12 patients receiving oxygen for 1 month regained sexual potency. The responders showed a significant increase in arterial pO₂ and serum testosterone, and a decline in SHBG compared to non-responders. None of the patients receiving oxygen for 24 h experienced reversal of sexual impotence, despite a significant increase in pO₂. In these patients, serum testosterone did not increase significantly. Reversal of sexual impotence may be achieved in some patients with respiratory failure. The oxygen therapy must, however be administered for an adequate length of time.     

Changes in the Secretory Profile of NSCLC-Associated Fibroblasts after Ablative Radiotherapy: Potential Impact on Angiogenesis and Tumor Growth

In the context of radiotherapy, collateral effects of ablative doses of ionizing radiation (AIR) on stromal components of tumors remains understudied. In this work, cancer-associated fibroblasts (CAFs) isolated from freshly resected human lung tumors were exposed to AIR (1x 18 Gy) and analyzed for their release of paracrine factors. Inflammatory mediators and regulators of angiogenesis and tumor growth were analyzed by multiplex protein assays in conditioned medium (CM) from irradiated and non-irradiated CAFs. Additionally, the profile of secreted proteins was examined by proteomics. In functional assays, effects of CAF-CM on proliferative and migratory capacity of lung tumor cells (H-520/H-522) and human umbilical vein endothelial cells (HUVECs) and their tube-forming capacity were assessed. Our data show that exposure of CAFs to AIR results in 1) downregulated release of angiogenic molecules such as stromal cell-derived factor-1, angiopoietin, and thrombospondin-2 (TSP-2); 2) upregulated release of basic fibroblast growth factor from most donors; and 3) unaffected expression levels of hepatocyte growth factor, interleukin-6 (IL-6), IL-8, IL-1β, and tumor necrosis factor-α. CM from irradiated and control CAFs did not affect differently the proliferative or migratory capacity of tumor cells (H-520/H-522), whereas migratory capacity of HUVECs was partially reduced in the presence of irradiated CAF-CM. Overall, we conclude that AIR mediates a transformation on the secretory profile of CAFs that could influence the behavior of other cells in the tumor tissue and hence guide therapeutic outcomes. Downstream consequences of the changes observed in this study merits further investigations.     

1,25-Dihydroxyvitamin D and the Vitamin D Receptor Gene Polymorphism Apa1 Influence Bone Mineral Density in Primary Hyperparathyroidism

Objective

Parathyroid hormone (PTH) and vitamin D are the most important hormones regulating calcium metabolism. In primary hyperparathyroidism (PHPT) excessive amounts of PTH are produced. Bone turnover is enhanced, leading to reduced bone mineral density and elevated levels of serum calcium. The aim of this study was to investigate relations between serum levels of 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D (1,25(OH)₂D) and bone mineral density, as well as known genetic polymorphisms in the vitamin D receptor and enzymes metabolising vitamin D in patients with PHPT.

Design/Subjects

We conducted a cross-sectional study of 52 patients with PHPT.

Results

Mean level of 25(OH)D was 58.2 nmol/L and median 1,25(OH)₂D level was 157 pmol/L. Among our patients with PHPT 36.5% had 25(OH)D levels below 50 nmol/L. Serum 1,25(OH)₂D was inversely correlated to bone mineral density in distal radius (p = 0.002), but not to bone mineral density at lumbar spine or femoral neck. The vitamin D receptor polymorphism Apa1 (rs7975232) was associated with bone mineral density in the lumbar spine.

Conclusions

The results suggest that PHPT patients with high blood concentrations of 1,25(OH)₂D may have the most deleterious skeletal effects. Randomized, prospective studies are necessary to elucidate whether vitamin D supplementation additionally increases serum 1,25(OH)₂D and possibly enhances the adverse effects on the skeleton in patients with PHPT.     

Regulation and intracellular trafficking pathways of the endothelin receptors

The effects of endothelin (ET) are mediated via the G protein-coupled receptors ET(A) and ET(B). However, the mechanisms of ET receptor desensitization, internalization, and intracellular trafficking are poorly understood. The aim of the present study was to investigate the molecular mechanisms of ET receptor regulation and to characterize the intracellular pathways of ET-stimulated ET(A) and ET(B) receptors. By analysis of ET(A) and ET(B) receptor internalization in transfected Chinese hamster ovary cells in the presence of overexpressed betaARK, beta-arrestin-1, beta-arrestin-2, or dynamin as well as dominant negative mutants of these regulators, we have demonstrated that both ET receptor subtypes follow an arrestin- and dynamin/clathrin-dependent mechanism of internalization. Fluorescence microscopy of Chinese hamster ovary and COS cells expressing green fluorescent protein (GFP)-tagged ET receptors revealed that the ET(A) and ET(B) subtypes were targeted to different intracellular routes after ET stimulation. While ET(A)-GFP followed a recycling pathway and colocalized with transferrin in the pericentriolar recycling compartment, ET(B)-GFP was targeted to lysosomes after ET-induced internalization. Both receptor subtypes colocalized with Rab5 in classical early endosomes, indicating that this compartment is a common early intermediate for the two ET receptors during intracellular transport. The distinct intracellular routes of ET-stimulated ET(A) and ET(B) receptors may explain the persistent signal response through the ET(A) receptor and the transient response through the ET(B) receptor. Furthermore, lysosomal targeting of the ET(B) receptor could serve as a biochemical mechanism for clearance of plasma endothelin via this subtype.     

The MHC class II-associated chicken invariant chain shares functional properties with its mammalian homologs

The nucleotide sequence of chicken invariant chain (Ii) was determined, and the amino acid sequence similarity with human Ii is 61%. Certain regions important for the biological function of human Ii are highly conserved between chicken and mammals. The cytoplasmic tail of chicken Ii fused to the plasma membrane reporter molecule neuraminidase relocated the protein to endosomes. Moreover, like the mammalian orthologs, the cytoplasmic tail was found to contain two independent leucine-based endosomal sorting signals. Chicken Ii was found to interact with human Ii and crosslinking studies also indicate that chicken Ii assembles as a trimer. The chicken Ii can furthermore bind the human MHC class II (HLA-DR1). Many of the functional properties between the chicken Ii and its mammalian orthologs are thus maintained in spite of their sequence differences.     

Lymphangiogenic Markers and Their Impact on Nodal Metastasis and Survival in Non-Small Cell Lung Cancer - A Structured Review with Meta-Analysis

Background

In non-small cell lung cancer (NSCLC), nodal metastasis is an adverse prognostic factor. Several mediating factors have been implied in the development of nodal metastases and investigated for predictive and prognostic properties in NSCLC. However, study results differ. In this structured review and meta-analysis we explore the published literature on commonly recognized pathways for molecular regulation of lymphatic metastasis in NSCLC.

Methods

A structured PubMed search was conducted for papers reporting on the expression of known markers of lymhangiogenesis in NSCLC patients. Papers of sufficient quality, presenting survival and/or correlation data were included.

Results

High levels of vascular endothelial growth factor C (VEGF-C, HR 1.57 95% CI 1.34–1.84) and high lymphatic vascular density (LVD, HR 1.84 95% CI 1.18–2.87) were significant prognostic markers of poor survival and high expression of VEGF-C, vascular endothelial growth factor receptor 3 (VEGFR3) and LVD was associated with lymph node metastasis in NSCLC.

Conclusion

Lymphangiogenic markers are prognosticators of survival and correlate with lymph node metastasis in NSCLC. Their exact role and clinical implications should be further elucidated.