title: Cholinesterase activity of human lung tumours varies according to their histological classification.
abstract: The probable involvement of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in cancer and the relevance of cholinergic responses for lung cancer growth prompted us to study whether cholinesterase activity of human lung is altered by malignancy. Surgical pieces of non-small lung carcinomas (NSLC) and their adjacent non-cancerous tissues (ANCT) were analysed for AChE and BChE activities. AChE activity in adenocarcinoma (AC) was 7.80 +/- 5.59 nmol of substrate hydrolysed per min and per mg of protein (mU/mg), the same as in their ANCT (8.83 +/- 4.72 mU/mg; P = 0.823); in large cell carcinoma (LCC), 7.52 +/- 3.32 mU/mg, approximately 50% less than in their ANCT (15.39 +/- 5.66 mU/mg; P = 0.043); and in squamous cell carcinoma (SCC), 1.39 +/- 0.58 mU/mg, 80% less than in ANCT (6.08 +/- 2.88 mU/mg; P = 0.003). BChE activity was 5.85 +/- 3.20 mU/mg in AC and 9.56 +/- 3.38 mU/mg in ANCT (P = 0.022); 2.94 +/- 2.01 mU/mg in LCC and 6.50 +/- 6.63 mU/mg in ANCT (P = 0.068); and 4.49 +/- 2.30 mU/mg in SCC and ANCT 6.56 +/- 4.09 mU/mg (P = 0.026). Abundant AChE dimers and fewer monomers were identified in lung and, although their distribution was unaffected by cancer, the binding with concanavalin A revealed changes in AChE glycosylation between SCC and their ANCT. The fall in BChE activity affected all molecules, with a strong decrease of the amphiphilic tetramers. Western blotting revealed protein bands with the expected mass of the principal AChE subunits, and the deeper intensity of the protein signal in SCC than in healthy lung, in lanes loaded with the same units of AChE activity, supported an augment in the amount of AChE protein/unit of AChE activity in SCC. The increased availability of acetylcholine in neoplastic lung, resulting from the fall of cholinesterase activity, may enhance cholinergic signalling and contribute to tumour progression.
authors.affiliation: Servicio de Análisis Clínicos and Cirugía Torácica, University Hospital Virgen de la Arrixaca, Ctra. Madrid-Cartagena s/n, El Palmar, E-30120, Murcia, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Martínez-Moreno
authors.forename: Susana
authors.initials: S
authors.lastname: Nieto-Cerón
authors.forename: Juan
authors.initials: J
authors.lastname: Torres-Lanzas
authors.forename: Francisco
authors.initials: F
authors.lastname: Ruiz-Espejo
authors.forename: Isabel
authors.initials: I
authors.lastname: Tovar-Zapata
authors.forename: Pedro
authors.initials: P
authors.lastname: Martínez-Hernández
authors.forename: José N
authors.initials: JN
authors.lastname: Rodríguez-López
authors.forename: Cecilio J
authors.initials: CJ
authors.lastname: Vidal
authors.forename: Juan
authors.initials: J
authors.lastname: Cabezas-Herrera
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000110:Acetylcholinesterase / Q000032:analysis / Q000378:metabolism*; D000368:Aged; D015153:Blotting, Western; D002091:Butyrylcholinesterase / Q000032:analysis / Q000378:metabolism*; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology* / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015398:Signal Transduction; D014018:Tissue Distribution
chemical_list: D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase; D000109:Acetylcholine