Cancer Stem Cells

Cancer Stem Cells

Cancer stem cells form a small but powerful group inside tumours. They can renew themselves and produce the different cell types that make up a cancer. Therefore, they drive tumour growth, spread, and return after treatment. Researchers first identified them in blood cancers. Later studies confirmed their presence in solid tumours as well.

These cells share features with normal stem cells. They divide slowly and resist many standard therapies. In addition, they express specific surface markers that help scientists isolate them. Once isolated, a few cancer stem cells can start a new tumour in laboratory models. This ability sets them apart from ordinary cancer cells, which usually lose the power to form tumours after a few divisions.

Several signalling pathways keep cancer stem cells alive and active. Wnt, Notch, and Hedgehog pathways regulate their self-renewal. Moreover, the surrounding tumour environment supplies signals that protect them. Low oxygen levels and certain metabolic changes further strengthen their survival. As a result, these cells often survive chemotherapy and radiation that kill the bulk of the tumour.

Cancer stem cells contribute to treatment failure and relapse across many cancer types. They can remain dormant for long periods and later restart growth. Furthermore, they help cancers spread to distant organs. Scientists now work on strategies that specifically target these cells. Approaches include blocking key pathways, disrupting their protective niche, and combining new agents with existing treatments.

In short, cancer stem cells explain why many tumours return after initial success. Understanding and eliminating them remains a major goal in modern cancer research.