Chordoma is a rare cancer that universally over expresses
brachyury and occurs in the base of the skull and spine.
In the case of cardiomyocytes,
brachyury, a-cardiac actin, atrial natriuretic factor and the specific sarcomeric myosin heavy chain (clone MF20) expression could be applied as markers of mature cardiomyocytes.
Most chordomas present high levels of expression of
brachyury, a key transcription factor for the development of notochord, being silenced after embryonic development.
The following markers were used to determine differentiation efficiency:
brachyury (R&D Systems) for mesoendoderm, Nkx2.5 (Abcam) for cardiac mesoderm, Nkx2.5 and Isl1 (Developmental Studies Hybridoma Bank) for cardiac progenitors, cTnT (Thermo Fisher Scientific) for cardiomyocytes, double staining of FOXA2 (GeneTex) and SOX17 (GeneTex) for endoderm, CDX2 (GeneTex) for mid/hindgut, Otx2 (R&D Systems) for day 5 neural induction, and PAX6 (GeneTex) for neuroepithelium [17-20].
The tumor cells are typically immunoreactive for cytokeratins, EMA, S100 protein, and
Brachyury, with the latter being highly specific (Figure 12, A through D).
Several findings appear to support the theory of a common ancestry, including the fact that the stromal cells express some proteins (stem cell leukemia,
brachyury) characteristic of embryonic progenitor cells with hemangioblastic differentiation potential [17].
"We herein report an exceptional case of extra-axial dedifferentiated chordoma confirmed by the expression of
brachyury, the first case report of this kind," reported surgical pathologist Dr.
It is important to note that in recent and improved studies, other markers were found to identify definitive endoderm, including Sox17,
Brachyury protein, CXC-chemokine receptor type 4, and Cerberus (73).
ZicL directly binds to an enhancer of
Brachyury, (63) which encodes a key transcription factor for differentiation of the notochord, and this binding confers competence for FGF induction on this gene.