Application of fluorescence difference gel electrophoresis saturation labelling for the analysis of microdissected precursor lesions of pancreatic ductal adenocarcinoma

Is current therapy of malignant gliomas beneficial for patients? Proteomics evidence of shifts in glioma cells expression patterns under clinically relevant treatment conditions

The most common human brain tumours - gliomas - have poor prognosis with and without treatment. The current therapy conditions act sub-lethally and cannot effectively suppress the proliferation of glioma cells. Here we show differential protein expression patterns in surviving human malignant U87-MG glioma cells under clinically relevant chemo/radiotherapy. In parallel experiments, the cells underwent either irradiation (2 Gy, 200 KV X-ray) or chemotreatment with 30 microg/mL of temozolomide in the cultivation medium or combined chemo/radiation treatment. The cell cultures were treated during 5 days from day 4 until day 9 of growth. Modulated expression patterns of vimentin and RhoA GTPase indicate a potentially increasing grade of malignancy in treated cell fractions correlating well with extremely aggressive tumour phenotypes observed clinically at recidivation of treated malignant gliomas.

Proteome analysis of glandular parotid and submandibular-sublingual saliva in comparison to whole human saliva by two-dimensional gel electrophoresis

The secretions of the salivary parotid and submandibular-sublingual (SMSL) glands constitute the main part of whole human saliva (WS) in which proline-rich proteins (PRPs) and mucins represent dominant groups. Although proteome analysis had been performed on WS, no identification of PRPs or mucins by 2-DE and MS was achieved in WS and no comprehensive analysis of both glandular secretions is available so far. The aim of this study was to compare the protein map of WS to parotid and SMSL secretions for the display of PRPs and mucins. WS and glandular secretions were subjected to 2-DE and spots were analyzed by MALDI-MS. New components identified in WS were cyclophilin-B and prolyl-4-hydroxylase. Also acidic and basic PRPs as well as the proline-rich glycoprotein (PRG) could now be mapped in WS. Acidic PRPs were found equally in parotid and SMSL secretions, whereas basic PRPs and PRG were found primarily in parotid secretion. Salivary mucin MUC7 was identified in SMSL secretion. Thus, the more abundant proteins of WS can be explained mainly by mixed contributions of parotid and SMSL secretions with only few components remaining that may be derived from local sources in the oral cavity.