Graded expression of microRNA-371a-3p in tumor tissues, contralateral testes, and in serum of patients with testicular germ cell tumor
Gazanfer Belge, Finja Hennig, Cansu Dumlupinar, Francesca Grobelny, Klaus Junker, Arlo Radtke, Klaus‐Peter Dieckmann
Abstract
// Gazanfer Belge 1 , * , Finja Hennig 1 , * , Cansu Dumlupinar 1 , * , Francesca Grobelny 1 , Klaus Junker 2 , Arlo Radtke 1 and Klaus-Peter Dieckmann 3 1 Faculty of Biology and Chemistry, University of Bremen, Bremen, Germany 2 Department of Pathology, Klinikum Bremen-Mitte, Bremen, Germany 3 Department of Urology, Asklepios Klinik Altona, Hamburg, Germany * These authors contributed equally to this work Correspondence to: Gazanfer Belge, email: [email protected] Keywords: testicular germ cell tumors; microRNA-371a-3p; serum; contralateral testes; in situ hybridization Received: February 11, 2020     Accepted: April 03, 2020     Published: April 21, 2020 ABSTRACT Background: Serum levels of microRNA-371a-3p represent a specific tumor marker of testicular germ cell tumors (GCTs) but the origin of circulating miR-371a-3p is not finally resolved. The correlation between miR-levels in tissue and serum is unclear. Results: MiR-levels in GCT tissue are 399-fold higher than in contralateral testicular tissue and 5843-fold higher than in non-testicular tissue. MiR tissue levels correlate with corresponding serum levels (r 2 = 0.181). ISH detected miR-371a-3p intracellularly in GCT cells except teratoma. A low expression was also detected in normal testicular germ cells. Conclusions: Circulating miR-371a-3p is specifically derived from GCT tissue. The miR is present in GCT cells except teratoma. A low expression is also found in normal testicular tissue but not in non-testicular tissue. MiR-371a-3p levels in tissue and serum correlate significantly. This study underscores the usefulness of serum miR-371a-3p as tumor marker of GCT. Patients and methods: Expression levels of miR-371a-3p were concurrently measured in tissues of GCT, contralateral testes ( n = 38), and in serum ( n = 36) with real time PCR. For control, 5 healthy testicles and 4 non-testicular tissue samples were examined. MiR-levels were compared using descriptive statistical methods. We also performed in situ hybridization (ISH) of GCT tissue with a probe specific for miR-371a-3p.