Research Article Details
| Article ID: | A34355 |
| PMID: | 23665184 |
| Source: | J Hepatol |
| Title: | Pleiotropic effects of methionine adenosyltransferases deregulation as determinants of liver cancer progression and prognosis. |
| Abstract: | Downregulation of liver-specific MAT1A gene, encoding S-adenosylmethionine (SAM) synthesizing isozymes MATI/III, and upregulation of widely expressed MAT2A, encoding MATII isozyme, known as MAT1A:MAT2A switch, occurs in hepatocellular carcinoma (HCC). Being inhibited by its reaction product, MATII isoform upregulation cannot compensate for MATI/III decrease. Therefore, MAT1A:MAT2A switch contributes to decrease in SAM level in rodent and human hepatocarcinogenesis. SAM administration to carcinogen-treated rats prevents hepatocarcinogenesis, whereas MAT1A-KO mice, characterized by chronic SAM deficiency, exhibit macrovesicular steatosis, mononuclear cell infiltration in periportal areas, and HCC development. This review focuses upon the pleiotropic changes, induced by MAT1A/MAT2A switch, associated with HCC development. Epigenetic control of MATs expression occurs at transcriptional and post-transcriptional levels. In HCC cells, MAT1A/MAT2A switch is associated with global DNA hypomethylation, decrease in DNA repair, genomic instability, and signaling deregulation including c-MYC overexpression, rise in polyamine synthesis, upregulation of RAS/ERK, IKK/NF-kB, PI3K/AKT, and LKB1/AMPK axis. Furthermore, decrease in MAT1A expression and SAM levels results in increased HCC cell proliferation, cell survival, and microvascularization. All of these changes are reversed by SAM treatment in vivo or forced MAT1A overexpression or MAT2A inhibition in cultured HCC cells. In human HCC, MAT1A:MAT2A and MATI/III:MATII ratios correlate negatively with cell proliferation and genomic instability, and positively with apoptosis and global DNA methylation. This suggests that SAM decrease and MATs deregulation represent potential therapeutic targets for HCC. Finally, MATI/III:MATII ratio strongly predicts patients' survival length suggesting that MAT1A:MAT2A expression ratio is a putative prognostic marker for human HCC. |
| DOI: | 10.1016/j.jhep.2013.04.031 |
| Target ID | Target Name | GENE | Action | Class | UniProtKB ID | Entry Name | |
|---|---|---|---|---|---|---|---|
| T01 | 5'-AMP-activated protein kinase subunit beta-1 | PRKAB1 | activator | Kinase | Q9Y478 | AAKB1_HUMAN | Details |
| T08 | Tumor necrosis factor | TNF | inhibitor | Cytokine | P01375 | TNFA_HUMAN | Details |
| T10 | Caspase-1 | CASP1 | inhibitor | Enzyme | P29466 | CASP1_HUMAN | Details |
| T20 | Fatty acid synthase | FASN | inhibitor | Enzyme | P49327 | FAS_HUMAN | Details |
| T23 | Type-1 angiotensin II receptor | AGTR1 | antagonist | GPCR | P30556 | AGTR1_HUMAN | Details |
| Diseases ID | DO ID | Disease Name | Definition | Class |
|---|
| Drug ID | Drug Name | Type | DrugBank ID | Targets | Category | Latest Progress | |
|---|---|---|---|---|---|---|---|
| D032 | Betaine | Chemical drug | DB06756 | DNMTs stimulant | Improve insulin resistance | Under clinical trials | Details |
| D579 | Emfilermin | Miscellany | -- | adipocytes | Enhance lipid metabolism | Under investigation | Details |
| D612 | Rapamycin | Miscellany | -- | Immunosuppressants; Methylmalonyl CoA mutase stimulants; MTOR protein inhibitors; T lymphocyte inhibitors | -- | Under investigation | Details |
| D328 | Serine | Chemical drug | DB00133 | SRR | Improve insulin resistance | Under clinical trials | Details |
| D010 | Amoxicillin | Chemical drug | DB01060 | -- | -- | Under clinical trials | Details |
| D140 | Folic acid | Supplement | DB00158 | FOLR2 binder | -- | Under clinical trials | Details |
| D080 | Citrulline | Chemical drug | DB00155 | -- | -- | Under clinical trials | Details |
| D248 | Obeticholic Acid | Chemical drug | DB05990 | NR1H4 activator; NR1H4 agonist; FXR agonist | Enhance lipid metabolism | Approval rejected | Details |
| D316 | S-adenosyl-L-methionine | Chemical drug | DB00118 | GNMT cofactor | Antiviral | Under clinical trials | Details |
| D158 | Glutathione | Chemical drug | DB00143 | MGST3; HPGDS; GSTM2; GSTM5; GPX7 cofactor; MGST2; GSS; GSTM1; GSTK1; GSTM3; GSTM4; GPX1 cofactor; GPX2 cofactor; GPX3 cofactor | -- | Under clinical trials | Details |