Cancer-associated differences in acetylcholinesterase activity in bronchial aspirates from patients with lung cancer.
In non-neuronal contexts, ACh (acetylcholine) is thought to be involved in the regulation of vital cell functions, such as proliferation, differentiation, apoptosis and cell-cell interaction. In airways, most cells express the non-neuronal cholinergic system, each containing a specific set of components required for synthesis, signal transduction and ACh hydrolysis. The aim of the present study was determine the expression of cholinergic system components in bronchial aspirates from control subjects and patients with lung cancer. We conducted an analysis of cholinergic components in the stored soluble and cellular fraction of bronchial aspirates from non-cancerous patients and patients diagnosed with lung cancer. The results show that the fluid secreted by human lung cells contains enough AChE (acetylcholinesterase) activity to control ACh levels. Thus these findings demonstrate that: (i) AChE activity is significantly lower in aspirates from squamous cell carcinomas; (ii) the molecular distribution of AChE in both bronchial cells and fluids consisted of amphiphilic monomers and dimers; and (iii) choline acetyltransferase, nicotinic receptors and cholinesterases are expressed in cultured human lung cells, as demonstrated by RT-PCR (reverse transcriptase-PCR). It appears that the non-neuronal cholinergic system is involved in lung physiology and lung cancer. The physiological consequences of the presence of non-neuronal ACh will depend on the particular cholinergic signalling network in each cell type. Clarifying the pathophysiological actions of ACh remains an essential task and warrants further investigation.
Martínez-López de Castro
Ana
A
Research Unit of Clinical Analysis Service, University Hospital Virgen de Arrixaca, Ctra Madrid-Cartagena s/n, El Palmar, 30120 Murcia, Spain.
Nieto-Cerón
Susana
S
Aurelio
Pons-Castillo
PC
Galbis-Martínez
Lilian
L
Latour-Pérez
Juan
J
Torres-Lanzas
Juan
J
Tovar-Zapata
Isabel
I
Martínez-Hernández
Pedro
P
Rodríguez-López
José Neptuno
JN
Cabezas-Herrera
Juan
J
D000110:Acetylcholinesterase / Q000235:genetics / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry*; D002294:Carcinoma, Squamous Cell / Q000201:enzymology; D005260:Female; D015870:Gene Expression; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014407:Tumor Cells, Cultured
D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D000110:Acetylcholinesterase