Iwata Ryoichi, Maruyama Masato, Ito Tomoki, Nakano Yosuke, Kanemura Yonehiro, Koike Taro, Oe Souichi, Yoshimura Kunikazu, Nonaka Masahiro, Nomura Shosaku, Sugimoto Tetsuo, Yamada Hisao, Asai Akio
Department of Neurosurgery, Kansai Medical University, Hirakata, Japan.
Department of Anatomy and Brain Science, Kansai Medical University, Hirakata, Japan.
Med Mol Morphol. 2017 Dec;50(4):211-219. doi: 10.1007/s00795-017-0160-0. Epub 2017 May 17.
Neuroendocrine tumors are rare, and little is known about the existence of cancer stem cells in this disease. Identification of the tumorigenic population will contribute to the development of effective therapies targeting neuroendocrine tumors. Surgically resected brain metastases from a primary neuroendocrine tumor of unknown origin were dissociated and cultured in serum-free neurosphere medium. Stem cell properties, including self-renewal, differentiation potential, and stem cell marker expression, were examined. Tumor formation was evaluated using intracranial xenograft models. The effect of temozolomide was measured in vitro by cell viability assays. We established the neuroendocrine tumor sphere cell line ANI-27S, which displayed stable exponential growth, virtually unlimited expansion in vitro, and expression of stem-cell markers such as CD133, nestin, Sox2, and aldehyde dehydrogenase. FBS-induced differentiation decreased Sox2 and nestin expression. On the basis of real-time PCR, ANI-27S cells expressed the neuroendocrine markers synaptophysin and chromogranin A. Intracranial xenotransplanted brain tumors recapitulated the original patient tumor and temozolomide exhibited cytotoxic effects on tumor sphere cells. For the first time, we demonstrated the presence of a sphere-forming, stem cell-like population in brain metastases from a primary neuroendocrine tumor. We also demonstrated the potential therapeutic effects of temozolomide for this disease.
神经内分泌肿瘤较为罕见，人们对该疾病中癌症干细胞的存在了解甚少。鉴定致瘤细胞群将有助于开发针对神经内分泌肿瘤的有效疗法。对来自原发灶不明的神经内分泌肿瘤的手术切除脑转移瘤进行解离，并在无血清神经球培养基中培养。检测了包括自我更新、分化潜能和干细胞标志物表达在内的干细胞特性。使用颅内异种移植模型评估肿瘤形成情况。通过细胞活力测定法在体外检测替莫唑胺的效果。我们建立了神经内分泌肿瘤球细胞系ANI-27S，该细胞系显示出稳定的指数生长、在体外几乎无限增殖，并表达干细胞标志物如CD133、巢蛋白、Sox2和醛脱氢酶。胎牛血清诱导的分化降低了Sox2和巢蛋白的表达。基于实时PCR，ANI-27S细胞表达神经内分泌标志物突触素和嗜铬粒蛋白A。颅内异种移植脑肿瘤重现了原患者肿瘤的特征，替莫唑胺对肿瘤球细胞表现出细胞毒性作用。我们首次证明了原发神经内分泌肿瘤脑转移瘤中存在形成球的、干细胞样细胞群。我们还证明了替莫唑胺对该疾病的潜在治疗效果。
