Isolating circulating tumor cells using a centrifuge on a chip

描述（由申请人提供）：下一代个性化抗癌治疗将越来越多地需要伴随诊断测试，以确定药物靶点的特定基因突变的存在。在血液循环或其他体液中，癌症组织或播散的癌细胞将需要进行这些检测。直接来自肿瘤的组织是理想的，因为它是高度纯净的，可以产生敏感的突变分析，但在某些情况下，这是不可用的，因为原发肿瘤可能已经被切除，微转移太小而无法活检，或者肿瘤存在于敏感的解剖部位附近，从而阻止了安全的手术进入。在这种情况下，弥散性肿瘤细胞存在于血液中是非常有用的，因为这是一个容易获得的来源。在伴随诊断中使用血液细胞的一个主要问题是在未处理的样本中存在大量背景白细胞；这些细胞阻止计数并压制来自罕见癌细胞的分子信号，因此必须去除以进行准确诊断。我们正在开发“芯片上的离心机”技术来应对这一挑战，并从血液样本中富集高纯度的罕见循环癌细胞。该装置创新性地利用惯性流体物理在高流体流速下产生微尺度的涡流，这种涡流可以选择性地、被动地分离较大的细胞，并将它们释放到芯片外的小体积流体中。我们已经用这种设备进行了一项初步研究，在这项研究中，我们从前列腺和膀胱晚期恶性肿瘤患者中分离出假定的肿瘤细胞，这些细胞可以用于下游分子分析。该技术易于使用，并且比当前的微流体细胞分离技术快一个数量级。我们的目标是验证离心芯片技术枚举循环肿瘤细胞作为癌症分期的功能，并评估用这种方法纯化的细胞是否能产生更高质量的遗传和突变分析。最终，这种设备可以提供成本效益高且快速的“液体活检”样本，可用于下游遗传分析，以便更有效地个性化抗癌治疗。

DESCRIPTION (provided by applicant): The coming generation of personalized anti-cancer treatments will increasingly require companion diagnostic tests to ascertain the presence of specific genetic mutations for which drug targets are available. Cancer tissue or disseminated cancer cells in the circulation or other bodily fluids will be required to carry out these assays. Tissue directly from the tumor is ideal because it is highly pure and can yield sensitive mutational analyses, but this is not available in certain cases as the primary tumor may have already been resected, micrometastases are too small to biopsy, or tumor is present near sensitive anatomical sites thus preventing safe surgical access. In such cases, disseminated tumor cells present in the blood can be highly useful as this is an easily accessible source. A major problem with using cells from blood in companion diagnostics is the presence of a large background of white blood cells within unprocessed samples; these cells prevent the counting and overpower the molecular signal from rare cancer cells and must therefore be removed for accurate diagnosis. We are developing the "Centrifuge on a Chip" technology to address this challenge and enrich rare circulating cancer cells from blood samples to high purity. This device innovatively utilizes inertial fluid physics at high fluid flow rates to generate microscale vortics which size-selectively and passively isolate larger cells and releases them into a small volume of fluid off chip. We have conducted a pilot study with this device in which we have isolated putative tumor cells from patients with advanced malignancies of the prostate and bladder and these cells can be processed for downstream molecular assays. This technology is easy to use and an order of magnitude faster than current microfluidic cell separation technologies. We aim to validate the Centrifuge Chip technology to enumerate circulating tumor cells as a function of cancer stage and to evaluate whether cells purified with this approach yield higher quality genetic and mutational analyses. Ultimately, such a device may provide a cost-effective and rapid 'liquid biopsy' sample which can be utilized for downstream genetic analyses in order to more effectively personalize anti-cancer therapy.