Evaluation of Real-Time In Vitro Invasive Phenotypes.

The methods described here provide a standardized process for assessing in vitro tumor cell migration and invasion in real time. The kinetic data generated under these standardized conditions are reproducible and characteristic of individual tumor cell lines. The complex kinetic features of the data can be analyzed using parameters modeled after pharmacokinetic data processing. Application of the method to the array of tumor types included in the National Cancer Institute's sixty cell line panel (NCI60) revealed distinct modes of invasion with some tumor cell lines utilizing a mesenchymal mode and generating information-rich kinetic profiles. Other cell lines utilized an amoeboid mode not suitable for detection with this method. The method described will be useful as a guide for tumor cell line selection and as a starting point in designing experiments probing migration and invasion.

Identification of CBX3 and ABCA5 as putative biomarkers for tumor stem cells in osteosarcoma.

Recently, there has been renewed interest in the role of tumor stem cells (TSCs) in tumorigenesis, chemoresistance, and relapse of malignant tumors including osteosarcoma. The potential exists to improve osteosarcoma treatment through characterization of TSCs and identification of therapeutic targets. Using transcriptome, proteome, immunophenotyping for cell-surface markers, and bioinformatic analyses, heterogeneous expression of previously reported TSC or osteosarcoma markers, such as CD133, nestin, POU5F1 (OCT3/4), NANOG, SOX2, and aldehyde dehydrogenase, among others, was observed in vitro. However, consistently significantly lower CD326, CD24, CD44, and higher ABCG2 expression in TSC-enriched as compared with un-enriched osteosarcoma cultures was observed. In addition, consistently higher CBX3 expression in TSC-enriched osteosarcoma cultures was identified. ABCA5 was identified as a putative biomarker of TSCs and/or osteosarcoma. Lastly, in a high-throughput screen we identified epigenetic (5-azacytidine), anti-microtubule (vincristine), and anti-telomerase (3,11-difluoro-6,8,13-trimethyl- 8H-quino [4,3,2-kl] acridinium methosulfate; RHPS4)-targeted therapeutic agents as candidates for TSC ablation in osteosarcoma.