Abstract
BackgroundThe M-type phospholipase A2 receptor (PLA2R1) plays a crucial role in several signaling pathways and may act as tumor-suppressor. This study examined the expression and methylation of the PLA2R1 gene in Jurkat and U937 leukemic cell lines and its methylation in patients with myelodysplastic syndrome (MDS) or acute leukemia.MethodsSites of methylation of the PLA2R1 locus were identified by sequencing bisulfite-modified DNA fragments. Methylation specific-high resolution melting (MS-HRM) analysis was then carried out to quantify PLA2R1 methylation at 5`-CpG sites identified with differences in methylation between healthy control subjects and leukemic patients using sequencing of bisulfite-modified genomic DNA.ResultsExpression of PLA2R1 was found to be completely down-regulated in Jurkat and U937 cells, accompanied by complete methylation of PLA2R1 promoter and down-stream regions; PLA2R1 was re-expressed after exposure of cells to 5-aza-2´-deoxycytidine. MS-HRM analysis of the PLA2R1 locus in patients with different types of leukemia indicated an average methylation of 28.9% ± 17.8%, compared to less than 9% in control subjects. In MDS patients the extent of PLA2R1 methylation significantly increased with disease risk. Furthermore, measurements of PLA2R1 methylation appeared useful for predicting responsiveness to the methyltransferase inhibitor, azacitidine, as a pre-emptive treatment to avoid hematological relapse in patients with high-risk MDS or acute myeloid leukemia.ConclusionsThe study shows for the first time that PLA2R1 gene sequences are a target of hypermethylation in leukemia, which may have pathophysiological relevance for disease evolution in MDS and leukemogenesis.
Highlights
The M-type phospholipase A2 receptor (PLA2R1) plays a crucial role in several signaling pathways and may act as tumor-suppressor
Two Ethylenediaminetetraacetic acid (EDTA)-blood samples of 18 patients with high-risk myelodysplastic syndrome (MDS) or Acute myeloid leukemia (AML), which were included in the clinical RELAZA trial [15] and who were treated with azacitidine (Vidaza; Celgene Corporation, Summit, NJ, USA; 75 mg/m2/day subcutaneously on days 1–7 of one course) were received for measurements of PLA2R1 gene methylation at the beginning and end of the treatment
The methylation of the PLA2R1 gene averaged 100% in both cell lines analyzed by MS-High resolution melting (HRM) analyses (Figure 1B) and sequencing (Figure 2B) of bisulfite-modified genomic DNA
Summary
The M-type phospholipase A2 receptor (PLA2R1) plays a crucial role in several signaling pathways and may act as tumor-suppressor. Phospholipases A2 (sPLA2, phosphatide sn-2-acylhydrolases, EC 3.1.1.4) belong to the superfamily of phospholipases that catalyze the hydrolysis of the sn-2 ester bond in phospholipids generating free fatty acids and lysophospholipids [1]. Both reaction products may function as bioactive lipid mediators. Three types of potential binding sites for sPLA2 have been identified; the N (neuronal)-type receptor, the M (muscle)-type receptor (PLA2R1), and integrins αvβ and α4β1. The N-type receptor is mainly expressed in neuronal tissues and likely plays an important role in the mediation of neurotoxic effects of sPLA2s [9]. A high binding affinity of sPLA2IIA to integrins of type αvβ and α4β1 was described in monocytic cells [6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
