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Updated: Mar 21, 2026
Employing Digital Droplet PCR to Detect BRAF V600E Mutations in Formalin-fixed Paraffin-embedded Reference Standard Cell Lines
Published on: October 8, 2015
Absence of microsatellite instability and BRAF (V600E) mutation in testicular germ cell tumors
F M Cárcano1,2, A H Lengert3,4, D O Vidal3,4
1Department of Medical Oncology, Barretos Cancer Hospital, Barretos, Brazil.
Abstract:
Testicular germ cell tumors (TGCT) are the most common malignant neoplasm in young men. DNA mismatch repair deficiency can lead to microsatellite instability (MSI), an important mechanism of genetic instability. A mutation of the BRAF gene has been implicated in the pathogenesis of several solid tumors and has recently become an important therapeutic target. The role of MSI and BRAF gene mutation in TGCT, particularly in refractory disease, is poorly understood and reported findings are controversial. In this study, we aimed to determine the frequency and clinical impact of MSI status and BRAF mutations in TGCT. DNA was isolated from formalin-fixed paraffin embedded (FFPE) tissue from 150 TGCT cases. The MSI phenotype was evaluated using multiplex PCR for five quasimonomorphic mononucleotide repeat markers. Exon 15 of the BRAF oncogene (V600E) was analyzed by PCR, followed by direct sequencing. Sixteen percent of cases were considered to have refractory disease. In a small subset of cases (17 for MSI and 18 for BRAF), the quantity and quality of DNA recovery were poor and therefore, were unable to be analyzed. The remaining 133 TGCT cases showed a complete absence of MSI. Of the 132 cases successfully evaluated for BRAF mutations, all were V600E wild-type. In conclusion, despite a distinct response of testicular germ cell tumors to therapy, microsatellite instability, and the BRAF V600E mutation were absent in all testicular germ cell tumors tested in this study.
Insights
Microsatellite instability (MSI) and BRAF V600E mutations were absent in all testicular germ cell tumors (TGCT) studied. This suggests these genetic alterations are not key drivers in TGCT pathogenesis or refractory disease.
Area of Science:
- Oncology
- Genetics
- Molecular Biology
Background:
- Testicular germ cell tumors (TGCT) are the most common cancer in young men.
- Microsatellite instability (MSI), a marker of genetic instability due to DNA mismatch repair deficiency, and BRAF mutations are implicated in various cancers.
- The role of MSI and BRAF mutations in TGCT, especially refractory cases, remains unclear with conflicting reports.
Purpose of the Study:
- To investigate the frequency and clinical significance of MSI and BRAF mutations in TGCT.
- To assess the potential of MSI and BRAF V600E as biomarkers or therapeutic targets in TGCT.
Main Methods:
- DNA extraction from 150 formalin-fixed paraffin-embedded (FFPE) TGCT tissues.
- MSI assessment using multiplex PCR for five mononucleotide repeat markers.
- BRAF V600E mutation analysis via PCR and direct sequencing of exon 15.
Main Results:
- A total of 133 TGCT cases were analyzed for MSI, with none exhibiting the instability phenotype.
- Out of 132 evaluable cases, all tested negative for the BRAF V600E mutation.
- Poor DNA quality prevented analysis in a small subset of cases (17 for MSI, 18 for BRAF).
Conclusions:
- The study found no evidence of microsatellite instability or BRAF V600E mutations in the tested TGCT cohort.
- These findings indicate that MSI and BRAF V600E are unlikely to be major contributors to TGCT development or treatment resistance.
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