The clinical practice of oncology is being transformed by molecular diagnostics that will enable predictive and personalized medicine. Over the past decade, there have been significant endeavors devoted to develop new-generation platform technologies for performing molecular analyses at genomic and proteomic levels using patient specimens, e.g., blood and tissue. In my presentation, I would like to intrude two in vitro molecular diagnostic technologies developed in my research group at UCLA. Please note that the validation studies of these systems have been ongoing at UCLA hospital using clinical specimens from cancer patients.

Current technologies for quantitation of the cancer proteome are either qualitative (e.g., immunohistochemistry) or require large sample sizes (e.g., flow cytometry). In the first part of my presentation, I will introduce a microfluidic platform, Microfluidic Image Cytometry1 (MIC), which is capable of quantitative, single-cell proteomic analysis of multiple signaling molecules using only 300-3,000 cells. Using both cultured cell lines and clinical brain tumor specimens, we demonstrated simultaneous measurement of four signaling proteins (EGFR, PTEN, phospho-Akt and phospho-S6) within the oncogenic PI3K/Akt/mTOR signaling pathway. To analyze the multiparameter, single-cell MIC measurements of brain tumor biopsies, we adapt bioinformatic methods including self-organizing maps that reveal significant intra- and inter-tumoral heterogeneity and permit stratification of patient samples into clusters, which predict patient survival. Together with bioinformatic analysis, the MIC platform represents an enabling in vitro molecular diagnostic technology for systems pathology analysis and personalized medicine. 

Circulating tumor cells (CTCs) has become an emerging “biomarker” for detecting early-stage cancer metastasis, predicting patient prognosis, as well as monitoring disease progression and therapeutic outcomes. However, isolation of CTCs has been technically challenging due to the extremely low abundance (a few to hundreds per ml) of CTCs among a high number of hematologic cells (109 per mL) in the blood. In the second part of my talk, I will discuss a new cell capture technology2 for quantification of CTCs in whole blood samples. Similar to most of the existing approaches, epithelial cell adhesion molecule antibody (anti-EpCAM) was grafted onto the surfaces to distinguish CTCs from the surrounding hematologic cells. We demonstrated the ability of these nanostructured substrates to capture CTCs in whole blood samples with significantly improved efficiency and selectivity. We have been able to bond our first validation study with a commercialized technology based on the use of immunomagnetic beads (i.e., CellSearchTM Assay). A group of clinically well-characterized prostate cancer patients have been recruited and tested in parallel by these two technologies.