Establishment of Primary Gnathic Malignant Mesenchymoma Cell Populations

Poorly differentiated sarcoma with features of malignant mesenchymoma is rare, aggressive tumor which may present with two or more types of mesenchymal differentiation. These tumors can occur in multiple tissues including muscle, fat, blood vessels and bone. Here, we report a rare gnathic (located in the jaw) malignant mesenchmoma with nonspecific immunophenotype. Objectives: 1) To establish a primary cell populations from a fresh gnathic (located in the jaw) malignant mesenchymoma specimen; 2) characterize gene expression profiles. Methods: Fresh tumor tissue was harvested from the surgical site of the right mandible of a 23 year old male; the sample was ascertained with IRB approval and signed consent. Tissue was dissected and grown as an explant culture in á-MEM supplemented with 10% fetal bovine serum (FBS), 100 units/mL penicillin and streptomycin. Cell populations were distinguished by morphology with two distinct types established: 1) round cell-like (SMT-B); and 2) spindle cell-like (SMT-B-1). The growth rates of the primary cells were measured using a MTS assay. Gene expression profiles were obtained by qRT-PCR gene profiling and immunohistochemistry focusing on mesenchymal markers, endothelial markers and epithelial markers. Markers analyzed were: vimentin, CD99, CD34, alkaline phosphatase (ALP), enamel matrix proteins, SIBLINGs, cytokeratin 14 (CK14) and cytokeratin 18 (CK18). Results: Cell growth rates between the cell populations varied with doubling time of 4 days (SMT-B) and more than 12 days (SMT-B-1). Both cell populations were strongly positive for vimentin and CD99, stained moderately for ALP, weakly for CD34, CK14 and CK18. No expression of enamel matrix proteins or SIBLNGS was detected. Conclusions: We have successfully established for the first time two primary gnathic malignant mesenchymoma cell populations with different properties. The establishment of the gnathic malignant mesenchymoma primary cell population will provide a valuable resource for determining tumor markers and serve as a therapeutic model. Support: UAB-SOD/IOHR.