Figure 1. Misregulation of cherub RNA causes tumor growth.

Neurons develop from neural stem cells called neuroblasts and specialized cells called intermediate neural progenitor (INP) cells. Landskron et al. found that a long non-coding RNA (lncRNA) named cherub has a role in the development of brain tumors. (A) In healthy flies, the protein Staufen (yellow half circle) anchors cherub (red half circle) to the basal part of the neuroblast cell membrane. After the neuroblast divides, cherub is inherited in the INP cell and spreads within it. As neuroblasts mature, they start to produce the protein Syncrip (Syp: green), which reduces the levels of a protein called Imp (blue). (B) In flies that lack the tumor suppressor gene brat, cherub remains at the cell membrane of the INP cells. When Syp is expressed as the neuroblast ages, it also remains anchored to cell membrane of the neuroblast by cherub and Staufen. This prevents Syp from repressing Imp, and some of the INP cells develop into tumor neuroblasts. (C) In flies that lack brat and cherub, cherub can no longer tether Syp; this allows Syp to inhibit Imp, and the neuroblasts are able to mature.