The Role of Tumor Stem Cells in Cancer Metastasis

Sydney Bach

Cancer metastasis (spread of cancer cells to other areas of the body) poses a significant challenge to cancer therapy due to the role of tumor stem cells (TSCs) in spreading and progression. Although low in number, these specialized cells in the tumor greatly contribute to cancer growth by allowing cancer to spread to other organs.

Characteristics of cancer stem cells that make them distinct include their capacity for self-renewal and their potential to differentiate into other cell types located in the tumor. This makes TSCs a crucial factor in promoting further tumor growth. These are also resistant to most common oncologic therapy methods, such as chemotherapy and radiation. In contrast to other types of cancerous cells, TSCs are able to handle harsh conditions in the tumor, including pockets that are lacking in oxygen.

The functions of tumor stem cells are closely associated with metastasis. TSCs are able to detach from where the cancerous tumor starts and travel throughout the circulatory or lymphatic system to reach distant areas. Upon settling down, they initiate the process of creating secondary tumors. The ability to travel and grow stems from the TSC's ability to promote the growth of new blood vessels, which provides growing tumors with oxygen.

Tumor stem cells additionally render cancer treatment more difficult because of their capability to restore damaged DNA and adapt to treatment strategies. As a result, even when the primary tumor is destroyed, these cells remain. This leads to the re-emergence of the cancer by increasing the likelihood of the metastasis process, causing cancers to develop resistance to therapy treatments. 

Researchers across the world are attempting to develop cancer therapies that are capable of targeting tumor stem cells specifically. These therapies are formulated to disrupt the signals that allow TSCs to survive and travel throughout the body to achieve better treatment outcomes. As we continue to make advances in understanding the function of TSCs, it is hoped that we will be able to develop more successful therapies that target the origin of cancer metastasis in the near future.

---

References

[1] Liu, K., Gao, X., Kang, B., Liu, Y., Wang, D., & Wang, Y. (2022). The role of tumor stem cell exosomes in cancer invasion and metastasis. Frontiers in Oncology, 12, 836548. https://doi.org/10.3389/fonc.2022.836548

[2] Liu, Y., Zhang, Z., & Wang, Z. (2018). The molecular mechanisms of tumor immune evasion. Journal of Biomedical Science, 25(1), 42. https://doi.org/10.1186/s12929-018-0426-4