Methotrexate induces apoptosis through p53/p21-dependent pathway and increases E-cadherin expression through downregulation of HDAC/EZH2.
Methotrexate (MTX) is a dihydrofolate reductase (DHFR) inhibitor widely used as an anticancer drug in different kinds of human cancers. Here we investigated the anti-tumor mechanism of MTX against non-small cell lung cancer (NSCLC) A549 cells. MTX not only inhibited in vitro cell growth via induction of apoptosis, but also inhibited tumor formation in animal xenograft model. RNase protection assay (RPA) and RT-PCR demonstrated its induction of p53 target genes including DR5, p21, Puma and Noxa. Moreover, MTX promoted p53 phosphorylation at Ser15 and acetylaion at Lys373/382, which increase its stability and expression. The apoptosis and inhibition of cell viability induced by MTX were dependent on p53 and, partially, on p21. In addition, MTX also increased E-cadherin expression through inhibition of histone deacetylase (HDAC) activity and downregulation of polycomb group protein enhancer of zeste homologue 2 (EZH2). Therefore, the anticancer mechanism of MTX acts through initiation of p53-dependent apoptosis and restoration of E-cadherin expression by downregulation of HDAC/EZH2.
Department of Pharmacology, College of Medicine, National Taiwan University, Taipei 10018, Taiwan.
Wen-Yu
WY
Huang
Pei-Ming
PM
Yang
Yu-Fan
YF
Chang
Victor E
VE
Marquez
Ching-Chow
CC
Chen
D017209:Apoptosis / Q000187:drug effects*; D015820:Cadherins / Q000235:genetics*; D002289:Carcinoma, Non-Small-Cell Lung / Q000178:diet therapy* / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D000071221:Enhancer of Zeste Homolog 2 Protein; D006655:Histone Deacetylases / Q000235:genetics*; D006801:Humans; D008727:Methotrexate / Q000494:pharmacology*; D063151:Polycomb Repressive Complex 2; D014157:Transcription Factors / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D015820:Cadherins; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004268:DNA-Binding Proteins; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; C498409:EZH2 protein, human; D000071221:Enhancer of Zeste Homolog 2 Protein; D063151:Polycomb Repressive Complex 2; D006655:Histone Deacetylases; D008727:Methotrexate