MicroRNA-profiling of miR-371~373- and miR-302/367-clusters in serum and cerebrospinal fluid identify patients with intracranial germ cell tumors
Stefan Schönberger, Mahsa Mohseni, Jörg Ellinger, Giao Vu Quynh Tran, Martina Becker, Alexander Claviez, Carl-Friedrich Classen, Bárbara Hermes, Pablo Hernáiz Driever, Norbert Jorch, Melchior Lauten, Marcus Mehlitz, Niklas Schäfer, Johanna Scheer-Preiss, Dominik T. Schneider, Anja Troeger, Gabriele Calaminus, Dagmar Dilloo
Abstract
Abstract Purpose Intracranial germ cell tumors (iGCT) comprise germinoma and non-germinoma. Their diagnosis predominantly relies on biopsy as only one-fifth of patients present with elevated biomarkers (AFP/ß-HCG) in serum or cerebrospinal fluid (CSF). MicroRNAs (miR/miRNA) have emerged as non-invasive biomarkers in extracranial GCT and may potentially facilitate non-invasive diagnosis in iGCT. Methods We analyzed eight miRNAs in serum and CSF from the miR-371~373- and miR-302/367-clusters and four miRNAs differentially expressed in iGCT tissue (miR-142-5p/miR-146a-5p/miR-335-5p/miR-654-3p) from eight iGCT patients (age 10–33 years) and 12 control subjects by pre-amplified RT-qPCR. MiR-30b-5p (serum) and miR-204-5p (CSF) acted as reference genes. Δ C t -values were expressed as $$2^{{ - \Delta \Delta C_{{\text{t}}} }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mn>2</mml:mn> <mml:mrow> <mml:mo>-</mml:mo> <mml:mi>Δ</mml:mi> <mml:mi>Δ</mml:mi> <mml:msub> <mml:mi>C</mml:mi> <mml:mtext>t</mml:mtext> </mml:msub> </mml:mrow> </mml:msup> </mml:math> after standardization against controls. Results Between iGCT and control patients’ serum Δ C t -values of miR-371a-3p ( p = 0.0159), miR-372-3p ( p = 0.0095, miR-367 ( p = 0.0190), miR-302a ( p = 0.0381) and miR-302d-3p ( p = 0.0159) differed significantly. Discriminatory pattern in CSF was similar to serum as miR-371a ( p = 0.0286), miR-372-3p ( p = 0.0028), miR-367-3p ( p = 0.0167) and miR-302d-3p ( p = 0.0061) distinguished between patients and controls. Abundant $$2^{{ - \Delta \Delta C_{{\text{t}}} }}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mn>2</mml:mn> <mml:mrow> <mml:mo>-</mml:mo> <mml:mi>Δ</mml:mi> <mml:mi>Δ</mml:mi> <mml:msub> <mml:mi>C</mml:mi> <mml:mtext>t</mml:mtext> </mml:msub> </mml:mrow> </mml:msup> </mml:math> levels of each of these miRNAs were found across all serum and CSF samples including biomarker-negative patients. Conclusion With the largest data set so far, we underline the suitability of miR-371a, miR-372, miR-367 and miR-302d in serum and CSF for diagnosis of iGCT, particularly in biomarker-negative germinoma. Diagnosis of iGCT by miRNA analysis is a feasible and valid approach, particularly as serum can be readily obtained by a less invasive procedure. MiRNA analysis may discriminate iGCT from other tumors with similar radiological findings and may allow to monitor response to therapy as well as early relapse during follow-up.