RX-3117 (Fluorocyclopentenyl-Cytosine)-Mediated Down-Regulation of DNA Methyltransferase 1 Leads to Protein Expression of Tumor-Suppressor Genes and Increased Functionality of the Proton-Coupled Folate Carrier

被引：5

作者：

Sarkisjan, Dzjemma ^{[1
]}

Julsing, Joris R. ^{[1
]}

El Hassouni, Btissame ^{[1
]}

Honeywell, Richard J. ^{[1
]}

Kathmann, Ietje ^{[1
]}

Matherly, Larry H. ^{[2
,3
]}

Lee, Young B. ^{[4
]}

Kim, Deog J. ^{[4
]}

Peters, Godefridus J. ^{[1
,5
]}

机构：

[1] Locat VU Univ Med Ctr, Amsterdam UMC, Lab Med Oncol, NL-1081 HV Amsterdam, Netherlands

[2] Wayne State Univ, Sch Med, Dept Oncol, Detroit, MI USA

[3] Barbara Ann Karmanos Canc Inst, Mol Therapeut Program, Detroit, MI 48201 USA

[4] Rexahn Pharmaceut Inc, Rockville, MD 20850 USA

[5] Med Univ Gdansk, Dept Biochem, PL-80210 Gdansk, Poland

来源：

INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES | 2020年 / 21卷 / 08期

关键词：

RX-3117; 5-aza-2 '-deoxycytidine; hypomethylation; proton-coupled folate receptor; methotrexate; FLUOROCYCLOPENTENYL-CYTOSINE; MEDIATED TRANSPORT; E-CADHERIN; METHYLATION; HYPERMETHYLATION; IDENTIFICATION; 5-AZACYTIDINE; METHOTREXATE; TEMOZOLOMIDE; MECHANISMS;

D O I：

10.3390/ijms21082717

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

(1) Background: RX-3117 (fluorocyclopentenyl-cytosine) is a cytidine analog that inhibits DNA methyltransferase 1 (DNMT1). We investigated the mechanism and potential of RX-3117 as a demethylating agent in several in vitro models. (2) Methods: we used western blotting to measure expression of several proteins known to be down-regulated by DNA methylation: O-6-methylguanine-DNA methyltransferase (MGMT) and the tumor-suppressor genes, p16 and E-cadherin. Transport of methotrexate (MTX) mediated by the proton-coupled folate transporter (PCFT) was used as a functional assay. (3) Results: RX-3117 treatment decreased total DNA-cytosine-methylation in A549 non-small cell lung cancer (NSCLC) cells, and induced protein expression of MGMT, p16 and E-cadherin in A549 and SW1573 NSCLC cells. Leukemic CCRF-CEM cells and the MTX-resistant variant (CEM/MTX, with a deficient reduced folate carrier) have a very low expression of PCFT due to promoter hypermethylation. In CEM/MTX cells, pre-treatment with RX-3117 increased PCFT-mediated MTX uptake 8-fold, and in CEM cells 4-fold. With the reference hypomethylating agent 5-aza-2 '-deoxycytidine similar values were obtained. RX-3117 also increased PCFT gene expression and PCFT protein. (4) Conclusion: RX-3117 down-regulates DNMT1, leading to hypomethylation of DNA. From the increased protein expression of tumor-suppressor genes and functional activation of PCFT, we concluded that RX-3117 might have induced hypomethylation of the promotor.

引用

页数：11