胶质瘤干／祖细胞诱导宿主巨噬细胞癌变的实验研究

Experimental study of glioma stem-progenitor cells inducing host macrophage canceration

目的探讨进展期肿瘤组织中的巨噬细胞是否癌变并对肿瘤生长起促进作用。方法将转染红色荧光蛋白（RFe）的人脑胶质瘤干／祖细胞（SU3）接种于12只表达绿色荧光蛋白（GFP）的裸小鼠腹腔，致瘤后取腹水或肿瘤结节培养，从GFP十细胞中克隆可传代的SU3细胞诱导的宿主腹腔肿瘤细胞株（SU3-ihCTC），并进行体外生长特性检测和分子表型试验、分子遗传学检测和致瘤试验。结果SU3-RFP／GFP荷瘤鼠腹水为血性，在肠系膜等腹腔脏器上长出许多肿瘤结节，取其培养细胞中RFP^＋和GFP^＋细胞，发现它们都具有增殖潜能，经单克隆的SU3-ihCTC细胞，具有生长接触抑制消失．增殖速度快，高集落形成率，染色体异倍体、端着丝粒等体外生长的癌细胞表型，而且在裸小鼠体内具有高致瘤率（12／12），同时表达巨噬细胞标志蛋白CD68。结论胶质瘤中被肿瘤细胞征集来的巨噬细胞不但能促进肿瘤细胞生长，而且自身已癌变。

Objective To explore whether macrophages-canceration happens in the tumor tissues during progressive stage and the promoting role of macrophages in growth of tumor stem cells. Methods Human glioma stem-progenitor cell line （SU3） transfected with red fluorescent protein gene （RFP） was inoculated in abdominal cavity of the athymic nude mice expressed green fluorescent protein （GFP）. Then ascites and tumor nodules were harvested from the tumor-bearing mice. GFP positive cells from the xenograft tumor tissue were separated, and in which the GFP positive cells with high proliferation ability were cloned. Related cancerous phenotypes, molecular genetics and tumorigenesis of the cloned GFP^＋ cells were further assayed. Results Bloody ascites were obtained from dual color tumor model and numerous of tumor nodules were found growing in the mesenteric and other abdominal organs. Both the RFP^＋ and part of GFP^＋ cells in the transplantable tumors had high proliferative potential. Monoclonal GFP^＋ cells were established from one single GFP＋ cell with micro-pipetting techniques, which behaved the cancer phenotypies of disappearance of growth contact inhibition, high proliferation rate, high colony formation rate and chromosome aneuploidy. Meanwhile monoclonal GFP^＋ cells also have 100% tumorigenicity rate in nude mice with expression ofmacrophage marker CD68. Conclusion In the RFP/GFP dual-color fluorescence SU3 abdominal xenograft tumors, part of host macrophages infiltrating the transplanted tumors with specific expression of CD68 are found to be undergoing canceration, which implies that host macrophages recruitmented by tumors not only promote tumor growth, but also experience canceration, which is of great significance to further study the tumor tissue remodeling and tumor microenvironment.