Bone Abstracts

Chordomas are rare, low to intermediate grade malignant bone tumors of the axial skeleton. Current treatment options are limited to surgical procedures as chordomas are largely resistant to conventional radiation and chemotherapy. Cell lines are valuable tools to explore molecular mechanisms involved in tumorigenesis and they have a fundamental impact on the development of new anticancer agents. We established a novel chordoma cell-line, MUG-Chor1, from a recurrent morphologically ‘classic’ sacrococcygeal chordoma of a 58-year-old Caucasian female.

In this current study, we first used the Aldefluor assay (Stemcell Technologies) and fluorescence-activated cell sorting (FACS) analysis to assess the presence and size of the cell population with ALDH1A1 enzymatic activity in three primary chordoma cell lines. ALDH1^high chordoma cells range from 0.35±0.34% (UCh1) to 1.39±0.56% (MUG-Chor1; n=10) of gated cells. ALDH1^high and ALDH1^low cells differed significantly in logarithmic growth velocity measured in a label-free real-time cell electronic sensing assay (RT-CES).

By investigating of important regulators of stem cell biology, the pluripotent stem cell proteome profiler array and real-time RT-PCR data showed an increased expression of SOX-2, SOX-17, E-cadherine, oct3/4, and goosecoid (GCS) in the ALDH1^high population. In the analysis of genes, which play an important role in the Wnt pathway, a significant difference in the expression of six genes between ALDH1^high and ALDH1^low cells could be demonstrated.

We have successfully used the Aldefluor assay for the isolation of ALDH1^high and ALDH1^low chordoma cells and showed significant differences in cell proliferation properties and the expression pattern of stem cell- and Wnt pathway genes.