MGMT and CALCA promoter methylation are associated with poor prognosis in testicular germ cell tumor patients

// Camila Maria da Silva Martinelli 1, 7 , Andre van Helvoort Lengert 1, 7 , Flavio Mavignier Carcano 2, 3, 7 , Eduardo Caetano Albino Silva 4, 7 , Mariana Brait 5 , Luiz Fernando Lopes 3, 6, 7 and Daniel Onofre Vidal 1, 6, 7 1 Pediatric Oncology Laboratory, Molecular Oncology Research Center, Barretos Cancer Hospital, Barretos, SP, Brazil 2 Department of Clinical Oncology, Barretos Cancer Hospital, Barretos, SP, Brazil 3 Barretos School of Health Sciences, Dr. Paulo Prata/FACISB, Barretos, SP, Brazil 4 Department of Pathology, Barretos Cancer Hospital, Barretos, SP, Brazil 5 Department of Otolaryngology and Head & Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA 6 Barretos Children’s Cancer Hospital, Barretos, SP, Brazil 7 Brazilian Childhood Germ Cell Tumor Study Group, Brazilian Pediatric Oncology Society, Sao Paulo, SP, Brazil Correspondence to: Luiz Fernando Lopes, email: lf.lopes@yahoo.com Daniel Onofre Vidal, email: daniel.vidal@hcancerbarretos.com.br Keywords: DNA methylation, biomarkers, prognosis, refractory disease, testicular germ cell tumor Received: January 25, 2016      Accepted: July 26, 2016      Published: August 10, 2016 ABSTRACT Testicular germ cell tumors (TGCT) represent the second main cause of cancer-related death in young men. Despite high cure rates, refractory disease results in poor prognosis. Epigenetic reprogramming occurs during the development of seminomas and non-seminomas. Understanding the molecular and genetic basis of these tumors would represent an important advance in the search for new TGCT molecular markers. Hence the frequency of methylation of a gene panel ( VGF, MGMT, ADAMTS1 , CALCA , HOXA9, CDKN2B, CDO1 and NANOG ) was evaluated in 72 primary TGCT by quantitative methylation specific PCR. A high frequency of MGMT (90.9%, 20/22; p=0.019) and CALCA (90.5%, 19/21; p<0.026) methylation was associated with non-seminomatous tumors while CALCA methylation was also associated with refractory disease (47.4%, 09/19; p=0.005). Moreover, promoter methylation of both genes predicts poor clinical outcome for TGCT patients (5-year EFS: 50.5% vs 77.1%; p=0.032 for MGMT and 51.3% vs 77.0%; p=0.029 for CALCA ). The findings of this study indicate that methylation of MGMT and CALCA are frequent and could be used as new molecular markers of prognosis in TGCT.