Ontario Cancer Institute/Princess Margaret Hospital, University of Toronto, Toronto, Ontario, Canada.
Cancer Res. 2011 Apr 15;71(8):3110-20. doi: 10.1158/0008-5472.CAN-10-4049. Epub 2011 Feb 22.
Hypoxia in solid tumors is associated with treatment resistance and increased metastatic potential. Although hypoxia has been reported in pancreatic cancer patients, there is little direct evidence that this contributes to their overall poor prognosis. To address this, we examined the associations between hypoxia and biological aggression in a series of patient-derived xenografts grown orthotopically. Early passage xenografts were established from 16 patients undergoing surgery for pancreatic cancer and maintained in the pancreas of immune-deprived mice. Hypoxic cells were labeled using the 2-nitroimidazole probe EF5 and stained for immunofluorescence microscopy of tissue sections or as cell suspensions for flow cytometry. Bromodeoxyuridine (BrdUrd) uptake, microvessel density, cleaved caspase-3, and the differentiation markers E-cadherin, cytokeratin 19, and vimentin were analyzed in relation to hypoxia. Orthotopic implants closely resembled the histology of the original surgical samples. The 16 primary xenografts showed a wide range in their growth rates and metastatic potential, reminiscent of the spectrum of behavior seen in the clinic. EF5 labeling, tumor growth rates, and metastatic patterns were highly consistent within replicates, indicating a significant transmissible (genetic or epigenetic) component. Hypoxia was highly correlated with rapid tumor growth, increased BrdUrd uptake, and with spontaneous metastasis formation. mRNA expression analysis showed increased expression of genes involved in cell survival and proliferation in the hypoxic models. The results suggest that hypoxia is a major adverse prognostic factor in pancreatic cancer patients and support the introduction of techniques to measure hypoxia directly in patients and the development of treatment protocols to target hypoxia.
实体肿瘤中的缺氧与治疗抵抗和增加的转移潜能有关。尽管已经在胰腺癌患者中报道了缺氧，但几乎没有直接证据表明这会导致他们整体预后不良。为了解决这个问题，我们在一系列原位生长的患者来源的异种移植体中检查了缺氧与生物学侵袭之间的关联。早期传代异种移植体从 16 名接受胰腺癌手术的患者中建立，并在免疫缺陷小鼠的胰腺中维持。使用 2-硝基咪唑探针 EF5 标记缺氧细胞，并对组织切片进行免疫荧光显微镜染色或作为细胞悬浮液进行流式细胞术染色。溴脱氧尿苷（BrdUrd）摄取、微血管密度、裂解的 caspase-3 以及分化标志物 E-钙粘蛋白、细胞角蛋白 19 和波形蛋白与缺氧相关进行了分析。原位植入物与原始手术样本的组织学非常相似。这 16 个原发性异种移植体在其生长速度和转移潜能方面表现出广泛的差异，类似于临床上所见的行为谱。EF5 标记、肿瘤生长速度和转移模式在重复实验中高度一致，表明存在显著的可传播（遗传或表观遗传）成分。缺氧与快速肿瘤生长、BrdUrd 摄取增加以及自发转移形成高度相关。mRNA 表达分析显示，缺氧模型中涉及细胞存活和增殖的基因表达增加。结果表明，缺氧是胰腺癌患者的一个主要不良预后因素，并支持直接在患者中测量缺氧的技术的引入和针对缺氧的治疗方案的开发。
