Co-regulation of proteins identified in human thyroid cells cultivated under simulated microgravity

Influence of gravity forces on the regulation of protein expression by healthy and malignant thyroid cells was studied with the aim to identify protein interactions. Western blot analyses of a limited number of proteins suggested a time-dependent regulation of protein expression by simulated microgravity. After applying free flow isoelectric focusing and mass spectrometry to search for differently expressed proteins by thyroid cells exposed to simulated microgravity for three days, a considerable number of candidates for gravi-sensitive proteins were detected. In order to show how proteins sensitive to microgravity could directly influence other proteins, we investigated all polypeptide chains identified with Mascot scores above 100, looking for groups of interacting proteins. Hence, UniProtKB entry numbers of all detected proteins were entered into the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and processed. The program indicated that we had detected various groups of interacting proteins in each of the three cell lines studied. The major groups of interacting proteins play a role in pathways of carbohydrate and protein metabolism, regulation of cell growth and cell membrane structuring. Analyzing these groups, networks of interaction could be established which show how a punctual influence of simulated microgravity may propagate via various members of interaction chains

Evaluation of the clinical value of bone metabolic parameters for the screening of osseous metastases compared to bone scintigraphy

BACKGROUND: Bone metastases are common in many types of cancer. As screening methods different imaging modalities are available. A new approach for the screening of osseous metastases represents the measurement of bone metabolic markers. Therefore aim of this study was to evaluate the usefulness of the determination of bone metabolic markers aminoterminal propeptide of type I procollagen (PINP, osteoblastic activity) and the carboxyterminal pyridinoline cross-linked telopeptide of type I collagen (ICTP, osteoclastic activity) for the detection of bone metastases associated with other malignancies. METHODS: 88 patients aged 21 – 82 years with malignant tumors were prospectively studied. The serum concentrations of PINP and ICTP were measured and compared to the results of bone scintigraphy, radiological bone series, CT, MRI and clinical follow-up. RESULTS: Osseous metastases were found in 21 patients. 19 of them were correctly identified by bone scintigraphy (sensitivity: 90%). For bone metabolic markers results were as follows: ICTP sensitivity: 71%, specificity: 42%; PINP sensitivity: 24%, specificity: 96%. CONCLUSIONS: As markers of bone metabolism PINP and ICTP showed low sensitivity and/or specificity for the detection of osseous metastases. The presented markers did not seem to be sufficient enough to identify patients with bone metastases or to replace established screening methods

T cells migrate to tumour sites after extracorporeal interleukin 2 stimulation and reinfusion in a patient with metastatic melanoma

Peripheral blood mononuclear cells (PBMC) were taken by leukapheresis from a patient with melanoma skin metastases and stimulated in vitro using 1000 IU recombinant interleukin 2 (IL-2)/ml to generate lymphokine-activated killer cells (LAK cells). Two-colour immunofluorescence analysis demonstrated an IL-2-induced up-regulation of CD25 on natural killer cells (CD56+) as well as on T lymphocytes (CD3+). After radiolabelling with indium-111, the cells were reinfused. Gamma-camera imaging revealed an enrichment at the tumour sites. Immunostaining of tumour tissue taken before and after scintigraphy demonstrated CD25+ T lymphocytes (CD2+, CD3+), but no natural killer cells (CD16+, CD56+) infiltrating the metastases. LAK cell enrichment at melanoma metastases in vivo did not involve natural killer cells, but was characterized by increased numbers of activated T lymphocytes in this patient

Imaging pattern of radiolabelled lymphokine-activated killer cells in patients with metastatic malignant melanoma

In patients with metastatic malignant melanoma the distribution patterns of radiolabelled lymphokine-activated killer (LAK) cells were investigated. Peripheral mononuclear cells (PMC) were isolated from six patients. LAK cells were generated by culturing PMC in complete medium containing 1000 U interleukin (IL)-2/ml and labelled with indium 111 before retransfer. We obtained scans at 2.5, 24, 48 or 96 h after injection with a high resolution gamma-camera. Intravenously injected LAK cells distributed to the lungs, liver, spleen and bone marrow. External tumour detection of known lymph node and bone metastases was successful in four. It failed in one patient with a solitary lung metastasis and in another patient with subcutaneous metastases. Our results suggest that LAK cells show tumour homing, providing a direct interaction between tumour and cytotoxic cells. We conclude that PMC seem to retain their ability to migrate after IL-2 stimulation and 111In-labeling. This technique may be helpful for kinetics studies or external detection of metastases in patients with malignant melanoma