gamma-Aminobutyric acid inhibits cholangiocarcinoma growth by cyclic AMP-dependent regulation of the protein kinase A/extracellular signal-regulated kinase 1/2 pathway.
- Additional Document Info
- View All
We studied the effect of the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA), in the regulation of cholangiocarcinoma growth. We determined the in vitro effect of GABA on the proliferation of the cholangiocarcinoma cell lines (Mz-ChA-1, HuH-28, and TFK-1) and evaluated the intracellular pathways involved. The effect of GABA on migration of Mz-ChA-1 cells was also evaluated. In vivo, Mz-ChA-1 cells were s.c. injected in athymic mice, and the effects of GABA on tumor size, tumor cell proliferation, apoptosis, collagen quantity, and the expression of vascular endothelial growth factor-A (VEGF-A) and VEGF-C (cancer growth regulators) were measured after 82 days. GABA decreased in vitro cholangiocarcinoma growth in a time-dependent and dose-dependent manner, by both cyclic AMP/protein kinase A- and D-myo-inositol-1,4,5-thriphosphate/Ca(2+)-dependent pathways, leading to down-regulation of extracellular signal-regulated kinase 1/2 phosphorylation. Blocking of GABA(A), GABA(B), and GABA(C) receptors prevented GABA inhibition of cholangiocarcinoma proliferation. GABA inhibited Mz-ChA-1 cell migration and, in vivo, significantly decreased tumor volume, tumor cell proliferation, and VEGF-A/C expression whereas increasing apoptosis compared with controls. An increase in collagen was evident in GABA-treated tumors. GABA decreases biliary cancer proliferation and reduces the metastatic potential of cholangiocarcinoma. GABA may represent a therapeutic agent for patients affected by malignancies of the biliary tract.
author list (cited authors)
Fava, G., Marucci, L., Glaser, S., Francis, H., De Morrow, S., Benedetti, A., ... Alpini, G
complete list of authors
Fava, Giammarco||Marucci, Luca||Glaser, Shannon||Francis, Heather||De Morrow, Sharon||Benedetti, Antonio||Alvaro, Domenico||Venter, Julie||Meininger, Cynthia||Patel, Tushar||Taffetani, Silvia||Marzioni, Marco||Summers, Ryun||Reichenbach, Ramona||Alpini, Gianfranco