Zhang Y, Kalderon D
Nature. 2001 Mar 29;410(6828):599-604. doi: 10.1038/35069099.
Secreted signalling molecules of the Hedgehog (Hh) family have many essential patterning roles during development of diverse organisms including Drosophila and humans. Although Hedgehog proteins most commonly affect cell fate, they can also stimulate cell proliferation. In humans several distinctive cancers, including basal-cell carcinoma, result from mutations that aberrantly activate Hh signal transduction. In Drosophila, Hh directly stimulates proliferation of ovarian somatic cells. Here we show that Hh acts specifically on stem cells in the Drosophila ovary. These cells cannot proliferate as stem cells in the absence of Hh signalling, whereas excessive Hh signalling produces supernumerary stem cells. We deduce that Hh is a stem-cell factor and suggest that human cancers due to excessive Hh signalling might result from aberrant expansion of stem cell pools.
刺猬索尼克（Hh）家族分泌的信号分子在包括果蝇和人类在内的多种生物体发育过程中具有许多重要的模式形成作用。尽管刺猬索尼克蛋白最常影响细胞命运，但它们也能刺激细胞增殖。在人类中，包括基底细胞癌在内的几种独特癌症是由异常激活Hh信号转导的突变引起的。在果蝇中，Hh直接刺激卵巢体细胞的增殖。在这里，我们表明Hh特异性作用于果蝇卵巢中的干细胞。在没有Hh信号的情况下，这些细胞不能作为干细胞增殖，而过量的Hh信号会产生多余的干细胞。我们推断Hh是一种干细胞因子，并认为由于Hh信号过量导致的人类癌症可能是由干细胞池的异常扩张引起的。
