Is acetylcholine an autocrine/paracrine growth factor via the nicotinic alpha7-receptor subtype in the human colon cancer cell line HT-29?

We used immunochemistry to demonstrate expression of acetylcholine's nicotinic alpha7-receptor subtype in human colon cancer cell line HT-29. Moreover, RT-PCR and immunochemistry showed that choline acetyltransferase and acetylcholine esterase, the enzymes responsible for acetylcholine synthesis and degradation, respectively, localise in HT-29 cells. Bromoacetylcholine bromide, an inhibitor of choline acetyltransferase, significantly attenuated basal cell growth. Our findings suggest that acetylcholine might serve as an autocrine/paracrine-or speculatively, even intracrine-signalling molecule in cell line HT-29, thus contributing to carcinogenesis/cancer progression.