Primary ductal carcinoma in situmammosphere formation: importance of the epidermal growth factor and Notch receptor signalling pathways

Excerpt

The cancer stem cell hypothesis suggests that targeting stem-like cells in cancer will improve current therapeutic strategies. In vitro culture of mammospheres (MS), colonies that are analogous to neurospheres, has been used to study factors affecting the self-renewal and growth of ductal carcinoma in situ (DCIS) in 29 cases. The MS culture system demonstrates a small subset of DCIS cells with self-renewal clonogenic capacity showing 1.5 ± 0.1% MS forming efficiency (MFE), which is greater than normal breast MFE, 0.5 ± 0.1% (P < 0.0001). DCIS MS demonstrated an increased growth rate compared with normal, yielding MS > 60 μm within 3 days rather than 7 days. The MFE was greater in high (1.6 ± 0.1%) compared with low (1.1 ± 0.1%, P = 0.012) histological grade DCIS, suggesting a link between the number of MS-initiating cells and recurrence rates. …