Overexpression of CREB protein protects from tunicamycin-induced apoptosis in various rat cell types.

Endoplasmic reticulum (ER) stress plays an essential role in unfolded protein response induced apoptosis contributing to several pathological conditions. Glycogen synthase kinase-3ß (GSK-3ß) plays a central role in several apoptotic signaling, including ER stress, as the active form of GSK-3ß induces apoptosis. The phosphorylation of cAMP responsive element (CRE) binding protein (CREB) Ser-133 (S133) residue is the end-point of various signaling pathways, like growth factor signaling, while the Ser-129 (S129) residue is phosphorylated by GSK-3ß. The significance of the ubiquitously expressed transcription factor CREB is demonstrated in prolonged, tunicamycin (TM)-induced ER stress in this study. In the experiments wild-type (wt) CREB, S129Ala, S133Ala or S129Ala-S133Ala mutant CREB expressing PC12 rat pheochromocytoma cell lines showed increased survival under TM-evoked prolonged ER stress compared to wtPC12 cells. After TM treatment ER stress was activated in all PC12 cell types. Lithium and SB-216763, the selective, well-known inhibitors of GSK-3ß, decreased TM-induced apoptosis and promoted cell survival. The proapoptotic BH3-only Bcl-2 family member Bcl-2-interacting mediator of cell death (Bim) level was decreased in the different CREB overexpressing PC12 cells as a result of TM treatment. CREB overexpression also inhibited the sequestration of Bim protein from tubulin molecules, as it was demonstrated in wtPC12 cells. Transient expression of wtCREB diminished TM-induced apoptosis in wtPC12, Rat-1 and primary rat vascular smooth muscle cells. These findings demonstrate a novel role of CREB in different cell types as a potent protector against ER stress.

Gene expression profiling in PC12 cells infected with an oncolytic Newcastle disease virus strain.

Although the oncolytic potential of natural, non-engineered Newcastle disease virus (NDV) isolates are well-known, cellular mechanisms determining NDV sensitivity of tumor cells are poorly understood. The aim of the present study was to look for gene expression changes in PC12 pheochromocytoma cells infected with an attenuated NDV strain that may be related to NDV susceptibility. PC12 cells were infected with the NDV strain MTH-68/H for 12h at a titer corresponding to the IC50 value. Total cytoplasmic RNA samples isolated from control and MTH-68/H-infected cells were analyzed using a rat specific Affymetrix exon chip. Genes with at least 2-fold increase or decrease in their expression were identified. MTH-68/H-induced gene expression changes of 9 genes were validated using quantitative reverse transcriptase PCR. A total of 729 genes were up- and 612 genes were down-regulated in PC12 cells infected with MTH-68/H. Using the DAVID functional annotation clustering tool, the up- and down-regulated genes can be categorized into 176 and 146 overlapping functional gene clusters, respectively. Gene expression changes affecting the most important signaling mechanisms (Toll-like receptor signaling, RIG-I-like receptor signaling, interferon signaling, interferon effector pathways, apoptosis pathways, endoplasmic reticulum stress pathways, cell cycle regulation) are analyzed and discussed in detail in this paper. NDV-induced gene expression changes described in this paper affect several regulatory mechanisms and dozens of putative key proteins that may determine the NDV susceptibility of various tumors. Further characterization of these proteins may identify susceptibility markers to predict the chances of virotherapeutic treatment of human tumors.

[A double immunochemical method for detecting faecal haemoglobin and albumin in rectal screening]. / Széklethemoglobin és -albumin kettos immunkémiai vizsgálat colorectalis szurésnél.

Undoubtedly, colonoscopy is the "gold standard" in the diagnosis of colorectal cancers. Sophisticated bowel preparation and risk of bowel perforation and bleeding, as well as the patient's discomfort during examination lead to low compliance in screening. Therefore, alternative non-invasive screening methods tend to come into the fore. In this study we compared the sensitivity and specificity of the double immunochemical FECA test for the haemoglobin + albumin content of the faeces with those of control colonoscopy in the detection of colorectal neoplasms. In a 3-year period 154 patients (69 males and 85 females) were scheduled for colonoscopy with previously collected stool samples. The sensitivity and specificity of the double immunochemical test for faecal haemoglobin + albumin content were determined in colorectal neoplasms of different severity. Colonoscopy served as a control examination. Colonoscopy identified in 77 cases benign lesions, and in 10 cases malignant tumours. The double immunochemical test for faecal blood and protein successfully used in model screening population showed in our present study 52.7% sensitivity and 92.3% specificity for significant neoplastic lesions (high-risk polyps and tumours). When the evaluation was limited to the high-risk polyps, the sensitivity was modified to 45.5% and the specificity to 92.3% and in case of invasive tumours to 90% and 100%, respectively. If only faecal haemoglobin content was measured, the overall sensitivity for polyps of any size and sort was 15.7% which, however, increased to 27.63% if faecal albumin was also measured. Based on relevant literature, the sensitivity of the FECA test for colorectal polyp and cancer is more favourable than that of other FITs. However, the increased sensitivity of the double faecal protein test falls short of the standard colonoscopy. Therefore, in certain cases the latter might be considered as a primary screening method.

[Production and examination of double antigen specific immunoserum for immunochemical detection of occult blood]. / Két antigént felismerô immunszérum elôállítása és vizsgálata a rejtett bélvérzés immunkémiai kimutatásához.

OBJECTIVES: The authors have developed an immunochemical procedure and an immunisation method for the simultaneous detection of fecal hemoglobin and albumin to increase the screening effectiveness of colorectal cancers. METHODS: In the human specific blood testing, bispecific immunoserum recognising two antigens have been produced by glutardyaldehyde-hemoglobin-albumin makromolecule immunisation of goats. The purified and concentrated antiserum with double antibody specifity has been checked in a screening group of 1196 individuals aged over 40 years with Fecatest reservoirs. RESULTS AND CONCLUSIONS: The analytical sensitivity was proved 0.5 microg/ml for both proteins, which was greatly favourable for the screening. Furthermore, the intensity of the immunochemical reactions has grown, and it has increased the safety of the detection without decreasing the specificity. Because the number of the immunochemical tests that could be completed at the same time has been doubled (without excess of cost), this method has increased the effectiveness of the screening with taking care of expense.