Snyder Eric L, Bailey Dyane, Shipitsin Michail, Polyak Kornelia, Loda Massimo
Center for Molecular Oncologic Pathology, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
Lab Invest. 2009 Aug;89(8):857-66. doi: 10.1038/labinvest.2009.54. Epub 2009 Jun 1.
Breast carcinoma cells with the CD44+/CD24(low) phenotype have been reported to exhibit 'cancer stem cell' (CSC) characteristics on the basis of their enhanced tumorigenicity and self-renewal potential in immunodeficient mice. We used immunohistochemistry to study the expression of these proteins in whole tissue sections of human breast carcinoma. We found that the fraction of CD44v6+ cells is higher in estrogen receptor-positive carcinomas after neoadjuvant chemotherapy. We also performed double immunohistochemistry for CD44v6 and for the proliferation marker Ki67. We found that the relative number of quiescent carcinoma cells is higher in the CD44v6+ population than in the CD44v6- population in specific carcinoma subtypes. We then used quantum dots and spectral imaging to increase the number of antigens that could be visualized in a single tissue section. We found that anti-CD44v6 and CD24 antibodies that were directly conjugated to quantum dots retained their ability to recognize antigen in formalin-fixed, paraffin-embedded tissue sections. We then performed triple staining for CD44v6, CD24 and Ki67 to assess the proliferation of each sub-population of breast carcinoma cells. Our results identify differences between CD44v6-positive and CD44v6-negative breast carcinoma cells in vivo and provide a proof of principle that quantum dot-conjugated antibodies can be used to study specific sub-populations of cancer cells defined by multiple markers in a single tissue section.
据报道，具有CD44+/CD24(低)表型的乳腺癌细胞在免疫缺陷小鼠中具有增强的致瘤性和自我更新潜力，因而表现出“癌症干细胞”(CSC)特征。我们采用免疫组织化学方法研究了这些蛋白在人乳腺癌全组织切片中的表达情况。我们发现，新辅助化疗后雌激素受体阳性癌中CD44v6+细胞的比例更高。我们还对CD44v6和增殖标志物Ki67进行了双重免疫组织化学检测。我们发现，在特定的癌亚型中，CD44v6+群体中静止癌细胞的相对数量高于CD44v6-群体。然后，我们使用量子点和光谱成像技术来增加在单个组织切片中可可视化的抗原数量。我们发现，直接与量子点偶联的抗CD44v6和CD24抗体在福尔马林固定、石蜡包埋的组织切片中仍保留其识别抗原的能力。然后，我们对CD44v6、CD24和Ki67进行三重染色，以评估乳腺癌细胞各亚群的增殖情况。我们的结果确定了体内CD44v6阳性和CD44v6阴性乳腺癌细胞之间的差异，并提供了一个原理证明，即量子点偶联抗体可用于研究由单个组织切片中的多个标志物定义的癌细胞特定亚群。
