Immunohistochemical Detection of Progranulin (PGRN/GP88/GEP) in Tumor Tissues as a Cancer Prognostic Biomarker

Progranulin Oncogenic Network in Solid Tumors

Progranulin is a pleiotropic growth factor with important physiological roles in embryogenesis and maintenance of adult tissue homeostasis. While-progranulin deficiency is associated with a broad range of pathological conditions affecting the brain, such as frontotemporal dementia and neuronal ceroid lipofuscinosis, progranulin upregulation characterizes many tumors, including brain tumors, multiple myeloma, leiomyosarcoma, mesothelioma and epithelial cancers such as ovarian, liver, breast, bladder, adrenal, prostate and kidney carcinomas. The increase of progranulin levels in tumors might have diagnostic and prognostic significance. In cancer, progranulin has a pro-tumorigenic role by promoting cancer cell proliferation, migration, invasiveness, anchorage-independent growth and resistance to chemotherapy. In addition, progranulin regulates the tumor microenvironment, affects the function of cancer-associated fibroblasts, and modulates tumor immune surveillance. However, the molecular mechanisms of progranulin oncogenic function are not fully elucidated. In bladder cancer, progranulin action relies on the activation of its functional signaling receptor EphA2. Notably, more recent data suggest that progranulin can also modulate a functional crosstalk between multiple receptor-tyrosine kinases, demonstrating a more complex and context-dependent role of progranulin in cancer. Here, we will review what is currently known about the function of progranulin in tumors, with a focus on its molecular mechanisms of action and regulation.

Progranulin/GP88, A Complex and Multifaceted Player of Tumor Growth by Direct Action and via the Tumor Microenvironment

Investigation of the role of progranulin/GP88 on the proliferation and survival of a wide variety of cells has been steadily increasing. Several human diseases stem from progranulin dysregulation either through its overexpression in cancer or its absence as in the case of null mutations in some form of frontotemporal dementia. The present review focuses on the role of progranulin/GP88 in cancer development, progression, and drug resistance. Various aspects of progranulin identification, biology, and signaling pathways will be described. Information will be provided about its direct role as an autocrine growth and survival factor and its paracrine effect as a systemic factor as well as via interaction with extracellular matrix proteins and with components of the tumor microenvironment to influence drug resistance, migration, angiogenesis, inflammation, and immune modulation. This chapter will also describe studies examining progranulin/GP88 tumor tissue expression as well as circulating level as a prognostic factor for several cancers. Due to the wealth of publications in progranulin, this review does not attempt to be exhaustive but rather provide a thread to lead the readers toward more in-depth exploration of this fascinating and unique protein.

[Preliminary Study on the Biological Markers for I-IIb Stage Non-small Cell Lung Cancer Based on a Serum-peptidomics]

背景与目的

非小细胞肺癌是发病率最高的一种肺恶性肿瘤，早发现、早诊断、早治疗是其治疗原则，因其发病隐匿，缺乏早期筛查的特异性标志物，多数患者就诊时已处于晚期阶段，导致其5年生存率较低，预后不理想。探索一种敏感的生物学标志物，是目前肺癌诊疗的重点。本文基于差异多肽组学技术，旨在筛选Ⅰ期-Ⅱb期非小细胞肺癌的血清生物标志物。

方法

利用纳升超高效液相色谱联合四级杆轨道阱质谱技术，比较和筛选正常健康人群、肺部良性病变患者、非小细胞肺癌患者血清中的差异多肽片段，通过对目标肽段的鉴别和定量分析，探寻非小细胞肺癌早期诊断的肿瘤生物标志物。

结果

通过与人类蛋白质组数据库进行比对，共鉴定到545个多肽，分别来自118个蛋白。将各组样本中肽段的谱图数进行比较，共筛选出201个差异多肽，经定量分析发现峰面积的变异系数（coefficient of variation, CV）≤30%的目标肽段共计7个，其中在各组间呈趋势变化的有2条肽段，分别是肺癌组中表达下调的肽段QGAKIPKPEASFSPR和肺癌组中表达上调的肽段CDDYRLC，它们分别来自于中间α球蛋白抑制因子H4蛋白（ITIH4）和基质γ-羧基谷氨酸蛋白（MGP）。

结论

将血清多肽组学用于筛选肿瘤标志物的研究，可为非小细胞肺癌的早期诊断提供新线索，其中ITIH4与MGP蛋白水解的特异性肽段是潜在早期非小细胞肺癌患者的血清标志物。