Mechanism of generation of pituitary adenomas based on theidentification of pituitary tumor stem cells

为了研究肿瘤干细胞在垂体腺瘤中的存在，并阐明肿瘤多样性与肿瘤发生发展的关系，我们从手术切除的标本中培养了垂体肿瘤干细胞。2例无功能垂体腺瘤、1例分泌GH的垂体腺瘤和1例分泌ACTH的垂体腺瘤均形成稳定的球体。在分化培养条件下，分别用抗GH抗体和抗ACTH抗体对GH腺瘤和ACTH腺瘤球状细胞进行免疫组化染色。从无功能的垂体腺瘤中分离出干细胞进行诱导分化时，观察到PRL和GH免疫染色阳性。此外，在肿瘤组织中还观察到Nestin阳性细胞的存在。从这些结果来看，垂体瘤干细胞可能存在于肿瘤组织中，并具有向多个方向分化的能力。

To investigate the presence of tumor stem cells in the pituitary adenoma, and to clarifythe relationship of tumor diversity and tumor development, we cultured pituitary tumorstem cells from surgical resected specimen. Stable sphere formation was obtained in twocases of non-functioning pituitary adenoma, one case of GH-secreting pituitary adenoma,and one case of ACTH-secreting pituitary adenoma. In the condition of differentiationmedia, sphere cells obtained from GH-secreting pituitary adenoma or ACTH-secretingpituitary adenoma were positively immunostained with anti-GH antibody or anti-ACTHantibody, respectively. When inducing differentiation of pituitary adenoma stem cellsextracted from the non functional pituitary adenoma was performed, positive PRL and GHimmunostaining became to be observed. Furthermore, the presence of Nestin-positive cellswas observed in tumor tissue. From these results, the pituitary tumor stem cells may existin the tumor tissue and have the ability to differentiate into multiple directions