尽管癌症干细胞的概念仍存在争议，但先前的研究表明，血癌以及特定类型的实体癌（例如结直肠癌）在肿瘤生长和进一步发展过程中依赖于干细胞。此外，白血病（例如急性髓系白血病）和结直肠癌对治疗的耐药性可归因于一小群具有干性特性（称为微小残留病）的细胞。在这篇综述中，我们回顾了癌症干细胞的发现以及血癌的发现对实体癌的平行发现的贡献。我们专注于 CD44 作为干细胞标记物，适用于血癌和几种类型的实体癌，特别是胃肠道癌。这篇综述重点介绍了新发现的 CD44 作用分子机制，表明 CD44 确实在干细胞性、干细胞维持和耐药性方面具有功能。我们在此尝试将 CD44 同工型在干性中的功能与其在肿瘤生长和转移的特定步骤中的参与联系起来。© 作者 2024。由牛津大学出版社出版。

Although the concept of cancer stem cells is still controversial, previous studies have shown that blood cancers, as well as specific types of solid cancers such as colorectal cancer, rely on stem cells during the onset of tumor growth and further tumor development. Moreover, resistance to therapeutic treatment in leukemias such as acute myeloid leukemia and in colorectal cancer can be attributed to a small population of cells with stemness properties known as minimal residual disease. In this review, we look back on the discovery of cancer stem cells and the contribution of the findings in blood cancer to a parallel discovery in solid cancers. We focus on CD44 as a stem cell marker, both in blood cancers and in several types of solid cancers, particularly of the gastro-intestinal tract. This review highlights newly discovered molecular mechanisms of action of CD44 which indicate that CD44 has indeed a function in stemness, stem cell maintenance and drug resistance. We attempt here to make the link between the functions of CD44 isoforms in stemness and their involvement in specific steps of tumor growth and metastasis.© The Author(s) 2024. Published by Oxford University Press.