Pera M F, Bennett W, Cerretti D P
Institute of Reproduction and Development, Monash University, Clayton, Victoria, Australia.
APMIS. 1998 Jan;106(1):169-72; discussion 173. doi: 10.1111/j.1699-0463.1998.tb01332.x.
Like the oocyte, the cells of the early embryo, and primordial germ cells, human teratocarcinoma stem cells are pluripotent, capable of giving rise to a wide range of somatic and extraembryonic tissues. Growth factors which regulate the growth of multipotent stem cells in the mouse have been identified, but none of these have been shown conclusively to have similar effects on human or primate multipotent stem cells. CD30 is a member of the tumour necrosis factor receptor superfamily with a restricted pattern of tissue distribution, limited to immune cells, decidual tissue, and human embryonal carcinoma: in common with other embryonal carcinoma markers, CD30 is found in foci of cells in a sub-population of seminomas. CD30 ligand is a transmembrane protein, structurally related to tumour necrosis superfamily members TNF alpha, TNF beta, and CD40. CD30 ligand is expressed by T and B lymphocytes, macrophages, and a variety of normal haematopoietic cells and tumours derived from them, and exerts pleiotropic effects on normal and malignant lymphoid cells, including death, differentiation, or cell division. Studies on cultured cell lines derived from human embryonal carcinomas and yolk sac carcinomas confirm CD30 expression in the former but not the latter, and show that CD30 expression is down-regulated during stem cell differentiation in vitro. Transcripts for CD30 ligand are found at highest levels in yolk sac carcinoma cell lines, but are also found in embryonal carcinoma. CD30 ligand protein is detected in yolk sac carcinoma and nullipotent embryonal carcinoma cell lines. Exogenous CD30 ligand has no effect on multipotent human stem cell growth in vitro. However, the receptor-ligand pair may function in autocrine regulation of embryonal carcinoma stem cells. CD30 and its ligand are candidate stem cell identity factors, juxtacrine regulators whose sole function is to identify a cell's position in a developmental hierarchy.
与卵母细胞、早期胚胎细胞和原始生殖细胞一样，人畸胎癌干细胞具有多能性，能够产生多种体细胞和胚外组织。已鉴定出调控小鼠多能干细胞生长的生长因子，但尚未确凿证明其中任何一种对人或灵长类多能干细胞有类似作用。CD30是肿瘤坏死因子受体超家族的成员，其组织分布模式受限，仅限于免疫细胞、蜕膜组织和人胚胎癌：与其他胚胎癌标志物一样，CD30在精原细胞瘤亚群的细胞灶中发现。CD30配体是一种跨膜蛋白，在结构上与肿瘤坏死超家族成员肿瘤坏死因子α、肿瘤坏死因子β和CD40相关。CD30配体由T和B淋巴细胞、巨噬细胞以及多种正常造血细胞及其衍生的肿瘤表达，并对正常和恶性淋巴细胞产生多效性作用，包括死亡、分化或细胞分裂。对源自人胚胎癌和卵黄囊癌的培养细胞系的研究证实，前者表达CD30，而后者不表达，并表明在体外干细胞分化过程中CD30表达下调。在卵黄囊癌细胞系中发现CD30配体的转录本水平最高，但在胚胎癌中也有发现。在卵黄囊癌和无潜能胚胎癌细胞系中检测到CD30配体蛋白。外源性CD30配体对体外多能人类干细胞生长无影响。然而，受体-配体对可能在胚胎癌干细胞的自分泌调节中起作用。CD30及其配体是候选干细胞身份因子，是旁分泌调节因子，其唯一功能是确定细胞在发育层次中的位置。
