The Src family kinase inhibitors PP2 and PP1 effectively block TGF-beta1-induced cell migration and invasion in both established and primary carcinoma cells.
OBJECTIVE
We have previously demonstrated that in pancreatic ductal adenocarcinoma (PDAC)-derived cell lines, the common Src family kinase inhibitors PP2 and PP1 effectively inhibited morphologic alterations associated with TGFβ1-mediated epithelial-to-mesenchymal transition (EMT) by blocking the kinase activity of the TGF-β type I receptor ALK5 rather than Src (Ungefroren et al. in Curr Cancer Drug Targets 11:524, 2011). In this report, the ability of PP2 and PP1, the more specific Src inhibitor SU6656, and the ALK5 inhibitor SB431542 to functionally block TGF-β1-dependent EMT and cell motility in established PDAC (Panc-1, Colo 357) and primary NSCLC (Tu459) cell lines were investigated.


METHODS
The effects of PP2, PP1, SU6656, and SB431542 on TGF-β1-dependent cell scattering/EMT, cell migration/invasion, and expression of invasion-associated genes were measured by using the real-time cell analysis assay on the xCELLigence system and quantitative real-time RT-PCR, respectively.


RESULTS
In all three cell lines tested, PP1, PP2, and SB431542 effectively blocked TGF-β1-induced cell scattering/EMT, migration, and invasion and in Colo 357 cells inhibited the induction of the invasion-associated MMP2 and MMP9 genes. In contrast, SU6656 only blocked TGF-β1-induced invasion in Panc-1 and Tu459 but not Colo 357 cells. PP1, and to a greater extent PP2, also inhibited the high spontaneous migratory activity of Panc-1 cells expressing a kinase-active ALK5 mutant.


CONCLUSIONS
These data provide evidence that PP2 and PP1 are powerful inhibitors of TGF-β-induced cell migration and invasion in vitro and directly target ALK5. Both agents may be useful as dual TGF-β/Src inhibitors in experimental therapeutics to prevent metastatic spread in late-stage PDAC and NSCLC.
Division of Hematology and Oncology, First Department of Medicine, UKSH, Campus Lübeck, 23538 Lübeck, Germany.
Tobias
T
Bartscht
Hendrik
H
Lehnert
Frank
F
Gieseler
Hendrik
H
Ungefroren
D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects*; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000235:genetics; D020780:Matrix Metalloproteinase 9 / Q000235:genetics; D009361:Neoplasm Invasiveness; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D011720:Pyrazoles / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D060888:Real-Time Polymerase Chain Reaction; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics; D013997:Time Factors; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*; D019061:src-Family Kinases / Q000037:antagonists & inhibitors*
C108123:4-amino-5-(4-methylphenyl)-7-(tert-butyl)pyrazolo(3,4-d)pyrimidine; C412373:AG 1879; D047428:Protein Kinase Inhibitors; D011720:Pyrazoles; D011743:Pyrimidines; D018125:Receptors, Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D019061:src-Family Kinases; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C000625841:TGFBR1 protein, human; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9