Morphological Characterization of Cardiomyocytes Isolated From a Transplantable Cardiac Tumor Derived From Transgenic Mouse Atria (AT-1 Cells)

• Published in: Circulation research 1991-12, Vol.69 (6), p.1591-1600
• Main Authors: Delcarpio, Joseph B, Lanson, Nicholas A, Field, Loren J, Claycomb, William C
• Format: Article
• Language: English
• Subjects: Animal tumors. Experimental tumors; Animals; Biological and medical sciences; Cell Differentiation; Cell Division; Experimental cardiovascular tumors; Heart Neoplasms - pathology; Heart Neoplasms - ultrastructure; Medical sciences; Mice; Mice, Transgenic; Microscopy, Electron; Mitosis; Myofibrils - ultrastructure; Neoplasm Transplantation; Tumor Cells, Cultured; Tumors
• ISSN: 0009-7330; 1524-4571
• DOI: 10.1161/01.res.69.6.1591

We have developed a transplantable tumor lineage derived from transgenic mouse atrial cardiomyocytes that express the SV40 large T oncogene and have named these cardiomyocytes AT-1 cells. In this study, the transplantable tumors, freshly isolated tumor cardiomyocytes, and cultured tumor cardiomyocytes were examined using phase-contrast microscopy, autoradiography, and electron microscopy. The vast majority of the subcutaneous tumor cells, >90% of the cellular mass of the tumor, exhibited sarcomeric banding. Ultrastructural characteristics typical of in vivo atrial cardiac muscle cells, including well-organized myofibrils, gap junctions, and atrial-specific cytoplasmic granules, were observed in in situ and in freshly isolated AT-1 cells. Those cells that did not contain some form of organized myofibrils were primarily vascular elements, such as endothelial cells. Labeling with [H]thymidine indicated that >90% of cultured AT-1 cells were synthesizing DNA; furthermore, many cells could be seen undergoing cell division. Electron microscopy revealed that the cultured AT-1 cardiomyocytes contained all of the above-described characteristics, including a well-developed transverse tubular system.