Pheochromocytoma tumor markers

Fig. 1. Pertussis toxin-mediated ADP ribosylation of membrane G proteins. Isolated cell membranes (50 ng of protein) from N1E 115 cells (mouse neuroblastoma cell line), N2A cells (mouse neuroblastoma cell line), S49-1 eye cells (S49(-) mutated mouse lymphoma cell line deficient in Ga ), 549 wt cells (wild-type mouse lymphoma cell line), RBL (RBL 2H3 rat basophilic leukemia cell line), GH3 cells (GH3 rat hypophyseal tumor cell line), PC-12 (rat pheochromocytoma cell line), HIT-T15 cells (hamster insulinoma cell line), Y-1 cells (mouse adrenal cortex tumor cell line), 108 cc 15 cells (mouse/rat neuroblastoma x glioma hybrid cell line), HL-60 cells (DMSO-differentiated human leukemia cell line), HL-60 (+PT) cells (HL-60 cells pretreated with 25 ng/ml of pertussis toxin for 24 h prior to preparation of membranes), RINm5F cells (rat insulinoma cell line), and C6-2 cells (rat glioma cell line) were subjected to P-ADP-ribosylation as described in section 4.3.3. Samples were precipitated as outlined in section 4.3.5 and subjected to SDS-PAGE with separating gels containing 8% acrylamide (w/v). An autoradiogram of the dried gel is shown. Molecular masses of marker proteins are indicated (kDa). Modified Ga proteins migrate at approximately 40 kDa. Radioactivity running in front of the 30 kDa marker protein comigrates with the dye front...

Monoamines share the acid environment of the storage granule matrix with ATP, peptides, and proteins, the most well known of which are the chromogranins. The chro-mogranins are ubiquitous components of secretory vesicles and their widespread presence among endocrine tissue has led to their measurement in plasma as useful albeit relatively nonspecific markers of neuroendocrine tumors, including pheochromocytomas and carcinoid tumors. 

Eisenhofer G, Reiser H, Friberg P, Mezey E, Huynh TT, Hiremagalur B, et al. Plasma metanephrines are markers of pheochromocytoma produced by catechoi-O-methyltransferase within tumors. J CUn Endocrinol Metab 1998 83 2175-85. 

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