LINE1 Methylation and Variation in Mitochondrial Genome in a Sample of Cancer Patients from Argentina.

PELTOMÄKI P.; PIÑERO, TAMARA ALEJANDRA; PAVICIC W.; CAJAL, ANDREA ROMINA; VACCARO, CARLOS; CERLIANI MB; VIGNOLLES F

Congreso; Reunión Conjunta de Sociedades de Biociencias. LXII Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2017

DNA methylation is a crucial epigenetic element involvedin gene regulation and genomic stability. LINE-1 methylationis widely accepted as surrogate marker for global genomic DNAmethylation, being hypomethylation a frequent event in cancer. Furthermore,nowadays it is suspected that mitochondrial DNA copynumber variation (mtDNA-CN) is related to methylation changes onnuclear gene promoters. As a preliminary approach, we conducteda case-control study on a set of DNA samples derived from 171controls and 212 cancer patients, all from Argentina: 75 patientswith onco-hematological diseases (Hem), 65 with breast cancer(BrCa) and 72 with colorectal carcinomas (CRC). Blood sampleswere available in all cases, and for solid tumors paired tumoral/non-tumoral adjacent tissues (T/N), were available too. LINE-1methylation level was analyzed by MS-MLPA method using a custom-made kit. mtDNA-CN were determined by qPCR. In BrCa, we found a significant mtDNA-CN decrease in 63% of the samples bycomparing Tvs.N tissue (average decrease=24%, p