Transforming growth factor beta1 alters calcium mobilizing properties and endogenous ATP release in A549 cells: possible implications for cell migration.
We examined the effects of transforming growth factor beta(1) (TGFbeta(1)) on cellular functions in human lung cancer cell line A549. Treatment of A549 cells with 1 ng/ml TGFbeta(1) for more than 3 days altered their morphology from an epithelial cobblestone-like appearance to a fibroblast-like one, reduced the expression of E-cadherin mRNA and protein, and induced the formation of F-actin fibers. These hallmarks indicate that TGFbeta(1) induced the epithelial-mesenchymal transition in A549 cells. Migration of TGFbeta(1)-treated A549 cells, which was quantified by the wound-healing assay, was markedly accelerated by 3 microM ATPgammaS, a non-hydrolyzable ATP analogue. ATPgammaS-induced migration of TGFbeta(1)-treated A549 cells was reversed by the P2 antagonist suramin. In contrast, migration of control A549 cells was not altered by ATPgammaS. TGFbeta(1)-treated A549 cells showed an augmentation of ATP-induced Ca(2+) transients, thapsigargin-induced Ca(2+) transients, and store-operated Ca(2+) entry compared with those in control cells. Basal level of the extracellular ATP concentration was significantly lower in TGFbeta(1)-treated A549 cells than in control cells. We conclude from these results that TGFbeta(1) augments ATP-induced Ca(2+) mobilization, which leads to the acceleration of migration, in A549 cells but, it markedly reduces endogenous ATP release. This implies that the actions of ATP would become a novel therapeutic target for inhibiting cancer cell migration.
Miki
Kenji
K
Department of Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Tanaka
Hiromitsu
H
Nagai
Yoko
Y
Kimura
Chiwaka
C
Oike
Masahiro
M
D000255:Adenosine Triphosphate / Q000378:metabolism*; D001483:Base Sequence; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D017931:DNA Primers; D006801:Humans; D020133:Reverse Transcriptase Polymerase Chain Reaction; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
D017931:DNA Primers; D053773:Transforming Growth Factor beta1; D000255:Adenosine Triphosphate; D002118:Calcium