Isolation of rare circulating tumor cells from blood using microbubbles

描述（由申请人提供）：在整个癌症病程中，转移性肿瘤细胞存在于血液和骨髓中（1-4）。这些循环肿瘤细胞（ctc）被认为是该疾病和体内远处转移的种子（5,6）。分离和表征ctc可以为不同阶段癌症的诊断、治疗和预后提供宝贵的信息（2,3,7）。血液中ctc的浓度通常很低，可低至每毫升血液1个细胞(8)。理想的分离技术必须能够以接近100%的效率特异性地从数十亿血细胞中捕获和分离单个ctc，而不会受到非特异性细胞的严重污染。我们建议使用靶向微泡（以下简称“微泡”）来开发一种分离和分析罕见肿瘤细胞的方法。作为一种细胞隔离技术，气泡可能比磁珠具有潜在的优势。我们在初步数据中表明，靶向气泡有效地附着在血液中的靶细胞上，因此细胞变得浮力，并且很容易通过重力/离心与所有其他细胞分离。本提案的目的是测试气泡分离是否可以达到磁珠分离的灵敏度，但具有更高的特异性、速度和生产率（能够处理10ml血液）。这些目标是可以在本合同规定的时间框架内实现的，以便我们评估是否有必要进一步发展。

DESCRIPTION (provided by applicant): It is well established that metastatic tumor cells are present in blood and bone marrow throughout the course of cancer disease (1-4). These circulating tumor cells (CTCs) are thought to seed the disease and distant metastases in the body (5,6). Isolating and characterizing the CTCs could provide invaluable information for diagnosis, treatment and prognosis of different stages of cancer (2,3,7). The concentration of CTCs in blood is typically low and can be as low as 1 cell/ml of blood (8). An ideal isolation technique has to be able to specifically capture and isolate single CTCs from billions of blood cells with close to 100% efficiency, without significant contamination by non-specific cells. We propose to use targeted microbubbles (hereafter ¿bubbles) to develop a method for isolation and analysis of rare tumor cells. ¿Bubbles could offer potential advantages over magnetic beads as a cell isolation technique. We show in our preliminary data that targeted ¿bubbles efficiently attach to their target cells in blood, so that the cells become buoyant and easily separate from all other cells using gravity/centrifugation. The goal of this proposal is to test whether the ¿bubble separation can achieve the sensitivity of magnetic bead separation, but with higher specificity, speed and productivity (ability to process >10 ml blood). These goals are achievable within the time frame of this award to allow us to assess whether further development is warranted. PUBLIC HEALTH RELEVANCE: To develop and to test tumor cell isolation technique for diagnosis of cancer. The technique will be based on the use of gas microbubbles that will attach to metastatic tumor cells in blood sample and will separate by buoyancy.