Skip to main content

01.12.2017 | Technical advance | Ausgabe 1/2017 Open Access

BMC Clinical Pathology 1/2017

Mapping mitochondrial heteroplasmy in a Leydig tumor by laser capture micro-dissection and cycling temperature capillary electrophoresis

BMC Clinical Pathology > Ausgabe 1/2017
Paulo Refinetti, Christian Arstad, William G. Thilly, Stephan Morgenthaler, Per Olaf Ekstrøm



The growth of tumor cells is accompanied by mutations in nuclear and mitochondrial genomes creating marked genetic heterogeneity. Tumors also contain non-tumor cells of various origins. An observed somatic mitochondrial mutation would have occurred in a founding cell and spread through cell division. Micro-anatomical dissection of a tumor coupled with assays for mitochondrial point mutations permits new insights into this growth process. More generally, the ability to detect and trace, at a histological level, somatic mitochondrial mutations in human tissues and tumors, makes these mutations into markers for lineage tracing.


A tumor was first sampled by a large punch biopsy and scanned for any significant degree of heteroplasmy in a set of sequences containing known mutational hotspots of the mitochondrial genome. A heteroplasmic tumor was sliced at a 12 μm thickness and placed on membranes. Laser capture micro-dissection was used to take 25000 μm2 subsamples or spots. After DNA amplification, cycling temperature capillary electrophoresis (CTCE) was used on the laser captured samples to quantify mitochondrial mutant fractions.


Of six testicular tumors studied, one, a Leydig tumor, was discovered to carry a detectable degree of heteroplasmy for two separate point mutations: a C → T mutation at bp 64 and a T → C mutation found at bp 152. From this tumor, 381 spots were sampled with laser capture micro-dissection. The ordered distribution of spots exhibited a wide range of fractions of the mutant sequences from 0 to 100% mutant copies. The two mutations co-distributed in the growing tumor indicating they were present on the same genome copies in the founding cell.


Laser capture microdissection of sliced tumor samples coupled with CTCE-based point mutation assays provides an effective and practical means to obtain maps of mitochondrial mutational heteroplasmy within human tumors.
Über diesen Artikel

Weitere Artikel der Ausgabe 1/2017

BMC Clinical Pathology 1/2017 Zur Ausgabe

Neu im Fachgebiet Pathologie

14.03.2019 | Originalien | Ausgabe 2/2019

Medikamentennachweise bei bayerischen Altenheimbewohnern – eine rechtsmedizinische Analyse

Erste Ergebnisse aus Screeninguntersuchungen an Urinproben

07.03.2019 | Mammakarzinom | CME | Ausgabe 2/2019

Update der S3-Leitlinie Mammakarzinom

Was gibt es Neues für Pathologen?

21.02.2019 | Schwerpunkt: Neuropathologie | Ausgabe 2/2019

Neuropathologie der Medulloblastome und anderer embryonaler Tumoren des ZNS

Präzisierung der Diagnostik durch Integration genetischer Marker