Background/Aim: Clinical management of testicular germ cell tumours (GCT) is based upon the measurement of serum tumour markers. Recent studies have shown that the microRNA-371a-3p is a sensitive and specific serum biomarker for all subgroups of GCT, except teratoma. To close the diagnostic gap relating to teratoma, serum levels of microRNA-375-3p have recently been suggested to represent a specific serum marker of this histological subgroup. In the present study, we tested this hypothesis. Materials and Methods: miRNA expression was analysed in serum of 21 GCT patients with teratoma, twelve patients with other GCT, and twelve male controls using the qPCR method. Results: The serum miR-375-3p levels of teratoma patients were not different from other GCT patients or controls. The ROC analysis revealed an AUC of 0.524 for the discrimination between teratoma and other pathologies. Conclusion: The miR-375-3p does probably not qualify for a useful serum biomarker to distinguish teratoma from other GCTs and from controls.

Purpose Serum levels of microRNA-371a-3p (M371) have been shown to be a highly sensitive and specific biomarker for testicular germ cell tumours (TGCT). Little information exists on the expression of this marker in testicular neoplasms deriving from the gonadal stroma or other structures of the gonad. This study presents an expression analysis of the novel TGCT-biomarker M371 in a large cohort of testicular non-germ cell tumours. Methods The M371 expression was measured by quantitative real time PCR in serum of 99 patients with testicular tumours of non-germ cell origin, thereof 30 patients with malignant testicular lymphomas and 61 patients with gonadal stroma tumours such as Leydig cell tumours, Sertoli cell tumours and 8 cases with miscellaneous benign testicular tumours. Their M371 levels were compared to those of 20 patients with TGCT and to 37 tumour-free male controls. Results The median expression levels of benign testicular tumours and testicular lymphoma are close to zero, thus, identical with those of controls and significantly lower than those of TGCT. In summary, this study provides further evidence for the notion that M371 is exclusively expressed by germ cell tumours and not by testicular neoplasms of the non-germ cell subtypes. Conclusion Clinically, the test might be of value in preoperative characterization of benign testicular tumours eligible for conservative surgery.

Background: The microRNAs of the miR-371-3 cluster are novel serum markers for testicular germ cell tumors. Sporadic reports suggested the expression of this miRNA in semen. Objectives: To verify the expression of miR-371a-3p in seminal plasma and unprocessed ejaculate; to compare seminal plasma miRNA levels in germ cell tumors patients with those of controls; to look for an association of miRNA levels with semen quality. Materials and methods: The miR-371a-3p expression was analyzed with qPCR. The study population consisted of 100 participants: seminal plasma samples from 20 germ cell tumors patients and 30 controls, serum samples from 12 healthy men, ejaculate samples from 38 men undergoing fertility testing. Results: The seminal plasma miR-371a-3p levels of germ cell tumors patients were not different from controls. The miRNA expression was very low in serum but much higher in seminal plasma. In ejaculate samples, the miRNA expression significantly correlated with sperm concentration and the total sperm count. Discussion: miR-371-a-3p is present in sperm-containing fluids. Seminal plasma levels cannot be used to distinguish germ cell tumors from controls. The correlation with sperm concentration in ejaculate samples suggests the spermatozoa as possible source of miR-371a-3p production. Conclusion: The miR-371a-3p levels in ejaculate could represent a novel biomarker for the non-invasive evaluation of male infertility.

Copyright: Belge et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 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.

BackgroundRadiological evaluation of postchemotherapy residual masses of metastatic seminoma is characterized by poor diagnostic accuracy. Serum levels of microRNA-371a-3p (M371) involve high specificity and sensitivity for the primary diagnosis of seminoma. We evaluated if M371 levels can indicate the presence of vital disease in postchemotherapy residual masses in patients with metastatic seminoma.MethodsTwenty-three seminoma patients (median age 52 years) with residual masses had posttreatment measurements of serum M371 levels (group A), fourteen of whom had measurements also beforehand. The posttreatment results were compared with the clinical outcome during follow-up. Eleven patients with complete remission after treatment of metastatic seminoma (group B) and 33 men with non-malignant testicular diseases (group C) served as controls. M371 serum levels were measured by quantitative real-time PCR using miR-30b-5p as endogenous control. An evaluation was performed with descriptive statistical methods.ResultsTwenty-two patients of Group A had uneventful follow-up so far, twenty-one of whom had M371 level <5, and one other had a mildly elevated level below relative quantity (RQ) = 10. One patient with a level of RQ = 26.2 rapidly progressed. The median posttreatment M371 level of the non-progressing patients of group A is not significantly different from the median level of the control group with complete remission (B). Before treatment, the median M371 levels in groups A and B were 507.6 and 143.9, respectively. In both groups, significant drops in M371 levels resulted from treatment.ConclusionNormal M371 serum levels at the time of completion of treatment of metastatic seminoma indicate the absence of vital seminoma in residual masses, while elevated levels >RQ = 10 predict the presence of disease. The optimal timing of M371 measurement after chemotherapy and the appropriate cutoff level still need to be determined. Based on the present results, measuring serum M371 levels involves the potential of a novel tool for assessing postchemotherapy residual masses of metastatic seminoma.