Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí sinh học đề tài : Methylation levels of the “long interspersed nucleotide element-1” repetitive sequences predict survival of melanoma patients | Sigalotti et al. Journal of Translational Medicine 2011 9 78 http content 9 1 78 JOURNAL OF TRANSLATIONAL MEDICINE RESEARCH Open Access Methylation levels of the long interspersed nucleotide element-1 repetitive sequences predict survival of melanoma patients 1 1 2 1 1 Luca Sigalotti Elisabetta Fratta Ettore Bidoli Alessia Covre Giulia Parisi Francesca Colizzi Sandra Coral Samuele Massarut3 John M Kirkwood4 and Michele Maio1 5 Abstract Background The prognosis of cutaneous melanoma CM differs for patients with identical clinico-pathological stage and no molecular markers discriminating the prognosis of stage III individuals have been established. Genome-wide alterations in DNA methylation are a common event in cancer. This study aimed to define the prognostic value of genomic DNA methylation levels in stage III CM patients. Methods Overall level of genomic DNA methylation was measured using bisulfite pyrosequencing at three CpG sites CpG1 CpG2 CpG3 of the Long Interspersed Nucleotide Element-1 LINE-1 sequences in short-term CM cultures from 42 stage IIIC patients. The impact of LINE-1 methylation on overall survival OS was assessed using Cox regression and Kaplan-Meier analysis. Results Hypomethylation . methylation below median at CpG2 and CpG3 sites significantly associated with improved prognosis of CM CpG3 showing the strongest association. Patients with hypomethylated CpG3 had increased OS P log-rank by Kaplan-Meyer analysis. Median OS of patients with hypomethylated or hypermethylated CpG3 were and months respectively. The 5 year OS for patients with hypomethylated CpG3 was 48 compared to 7 for patients with hypermethylated sequences. Among the variables examined by Cox regression analysis LINE-1 methylation at CpG2 and CpG3 was the only predictor of OS Hazard Ratio for hypermethylated CpG3 95 Confidence Interval P . Conclusion LINE-1 methylation is identified as a molecular .
