Methylation Pattern of GSTP۱ Gene as aBiomarker in Acute Lymphoblastic Leukemia Using MassSpectrometry

Background: Acute lymphoblastic leukemia (ALL) is usuallymore common among children and difficult to diagnose, becausemany of the symptoms of leukemia in children are similarto childhood diseases. In order to prevent, treat and diagnosethis disease, there is a need for molecular examination of bloodcancer. Too sensitive methods based on mass spectrometry,which are leading in many fields today, can be studied as animportant factor in identifying and evaluating the response totreatment.Materials and Methods: In this study, to investigate the epigenomicsof this cancer, GSTP۱ gene was studied as a biomarker.In this method, the time-consuming process of bisulfitemodification and PCR has been removed and after extractionof DNA from the samples, it was hydrolyzed by using a restrictionenzyme. The reaction of GSTP۱ gen fragment with thebiotinylated probe and isolation of this complex with magneticnanoparticles (MNPs) coated with streptavidin. The determinedmethylation of the target region using a high technique byMALDI-TOF MS causes to have a more rapid and too sensitivemethod to follow of ALL.Results: The spectrum of MNPs was taken (before and after reactionwith biotinylated probe) in positive and negative modesin MALDI-TOF MS, which were different from each other. Toobserve the total mass (taking into account the molecular massof the promoter of GSTP۱ gene after enzymatic cleavage, themolecular mass of the biotinylated probe and methyl groups),the spectrum was deconvoluted in the negative mode (from theMNPs reacted with the probe) and finally methylation was observedin ۱۸ regions of cytosine groups and the total molecularmass was observed, which indicates the methylation of patient’ssamples in the target region.Conclusion: The presented method is a too sensitive methodthat was able to prove the methylation of the target region withoutusing bisulfite and PCR techniques. This fast and accuratemethod can be a suitable alternative for diagnosis methods, responseto treatment and molecular investigation of cancer genetics.In the following, after proving and specifying the amountof methylation in the promoter region of GSTP۱ in the patient'ssample, we seek to determine the exact location of methylationin the promoter region through the Tandem MS technique

کلیدواژه ها:

Methylation of GSTP۱ gene ، Mass Spectrometry Acute Lymphoblastic Leukemia ، Streptavidin