Phenylethynyl-substituted heterocycles inhibit cyclin D1 and induce the expression of cyclin-dependent kinase inhibitor p21Wif1/Cip1in colorectal cancer cells

Fluorinated, phenylethynyl-substituted heterocycles that possessed either an N -methylamino or N,N -dimethylamino group attached to heterocycles including pyridines, indoles, 1 H -indazoles, quinolines, and isoquinolines inhibited the proliferation of LS174T colon cancer cells in which the inhibition of cyclin D1 and induction of the cyclin-dependent kinase inhibitor-1 ( i.e ., p21 Wif1/Cip1 ) served as a readout for antineoplastic activity at a cellular level. On a molecular level, these agents, particularly 4-((2,6-difluorophenyl)ethynyl)- N -methylisoquinolin-1-amine and 4-((2,6-difluorophenyl)ethynyl)- N , N -dimethylisoquinolin-1-amine, bound and inhibited the catalytic subunit of methionine S-adenosyltransferase-2 (MAT2A).