Sung-Chi Tsai, Lien-Yu Hung, Gwo-Bin Lee

Gynecological cancer is difficult to be diagnosed at early stages. The relatively high mortality rate has been a serious issue accordingly. We herein reported a diagnosis method by using circulating tumor cells (CTCs) which have been extensively explored as a potential tool for diagnostics and prognostics of ovarian cancers. Nonetheless, the detection of CTCs still remains a challenge because of the difficulty in isolating them from whole blood samples since they are shed into the vasculature from primary tumors and circulate irregularly in the bloodstream in extremely low concentrations. In this work, we reported a new, integrated microfluidic system capable of (1) red blood cells lysis, (2) white blood cell (WBC) depletion via a negative selection process, and (3) capture of target cancer cells from whole blood samples using aptamer-binding technology. Furthermore, this is the first time that an aptamer was used to capture ovarian cancer cells owing to its high affinity. The new microfluidic chip could efficiently perform the entire process in one hour without human intervention at a high recovery rate and a low false positive detection rate when compared with antibody-based systems. A high recovery rate for the isolation of CTCs within a short period of time has been reported when compared to the traditional negative or positive selection approach by using traditional antibody biomarkers. More importantly, "false positive" results from WBCs could be significantly alleviated due to the high specificity of the cancer cell-specific aptamers. The developed integrated microfluidic system could be promising for the isolation and detection of CTCs, which could be used for early diagnosis and prognosis of cancers.