Role of inflammation, innate resistance, and immunity in carcinogenesis.

该项目的几个目标已取得进展：促炎髓细胞受体TREM-1控制Kupffer细胞的激活和肝细胞癌的发展（Cancer Res. 2012;72:3977-86）。慢性炎症驱动肝癌的发病、侵袭和转移。肝库普弗细胞在促进肝癌的炎症过程中起着至关重要的作用，但其作用的机制基础尚不完全清楚。本研究表明，Kupffer细胞表达的促炎髓细胞表面受体TREM-1是肝癌发生发展的关键因素。小鼠同源基因Trem1的缺失减轻了二乙基亚硝胺（DEN）引发的肝细胞癌变。Trem1缺乏通过下调白细胞介素(IL)-6、IL-1 β、TNF、CCL2和CXCL10的转录和蛋白表达来减弱库普弗细胞的活化。此外，Trem1消融降低了Kupffer细胞中p38、细胞外调节激酶1/2、JNK、丝裂原活化蛋白激酶和NF-kB信号通路的激活，导致DEN暴露后肝损伤减轻。将野生型Kupffer细胞过继移植到trem1缺陷小鼠体内，弥补了这些缺陷，并逆转了对den诱导的肝损伤和恶性发展的无反应性。总之，我们的研究结果提供了因果证据，表明TREM-1是肝癌发生中Kupffer细胞激活的关键决定因素，深化了慢性炎症如何支持肝癌发生和进展的机制见解。NK细胞来源的干扰素- γ协调细胞动力学和单核细胞向树突状细胞的分化在感染部位的先天抵抗和促炎性细胞因子在癌变中的作用（免疫，2012;36:1047-59）。树突状细胞（dc）、单核细胞和/或巨噬细胞对细胞内病原体启动宿主保护性免疫反应，部分是通过白细胞介素-12 （IL-12）的产生，尽管组织驻留细胞和募集细胞的相对贡献尚不清楚。本研究表明，在腹腔内感染弓形虫囊后，原有的单核吞噬细胞被循环的单核细胞取代，单核细胞原位分化为炎性DCs （moDCs）和F4/80+巨噬细胞。重要的是，NK细胞来源的干扰素- γ (ifn - γ)对于常驻单核吞噬细胞的损失和单核细胞向巨噬细胞和modc的局部分化都是必需的。这种新产生的moDC群体，而不是常驻的dc（或巨噬细胞），是感染部位IL-12的主要来源。因此，NK细胞衍生的ifn - γ在调节炎症细胞动力学和驱动单核细胞局部分化为启动对重要细胞内病原体的免疫应答所需的细胞方面都很重要。一项非常广泛的研究已经开始研究炎症受体和细胞因子在皮肤和结肠化学致癌中的作用。在几种癌症模型中，通过接头蛋白MyD88的信号传导促进了癌变。相反，MyD88信号在偶氮氧甲烷(AOM)/葡聚糖硫酸钠（DSS）结肠炎相关癌症（CAC）的发展中具有保护作用。Myd88-/-小鼠无法愈合损伤后产生的溃疡，导致炎症环境改变，导致编码促炎因子的基因表达早期改变，以及调节细胞增殖、凋亡和DNA修复的途径，导致腺瘤形成和浸润性腺癌的急剧增加，β -连环蛋白基因频繁发生克隆突变。这项研究揭示了MyD88下游不同受体影响组织稳态和癌变的复杂程度。白细胞介素- 1r - myd88信号通路在人角质细胞转化中的作用[J] .中华医学杂志。2012;29(2):334 - 334。组成型活性RAS在人类癌症的发展中起着核心作用，并足以在两阶段皮肤癌变中诱导肿瘤。ras介导的肿瘤形成通常与细胞因子和趋化因子的上调有关，这些细胞因子和趋化因子介导的炎症反应被认为与肿瘤发生有关。在这项研究中，我们报告了缺乏IL-1R或MyD88的小鼠对局部皮肤癌的敏感性低于其各自的野生型（WT）对照。表达致癌RAS的MyD88（-/-）或IL-1R（-/-）角质形成细胞具有高增殖性，不能上调促炎基因或下调表达RAS的WT角质形成细胞所特有的分化标记。虽然表达ras的MyD88（-/-）角化细胞在原位移植物中仅形成少数小肿瘤，但表达il - 1r缺陷的ras角化细胞保留了在原位移植物中形成肿瘤的能力。使用遗传学和药理学方法，我们发现角化细胞中致癌RAS的分化和促炎作用需要通过il - 1α、IL-1R和MyD88建立自分泌环，导致IkBalpha磷酸化和NF-kB活化。在表达ras的WT角质形成细胞中阻断il -1 α介导的NF-kB活化可逆转分化缺陷并抑制促炎基因表达。总之，这些结果表明MyD88在ras介导的角质形成细胞转化中发挥细胞内在功能。腺瘤相关屏障缺陷和微生物产物驱动IL-23/ il -17介导的肿瘤生长（Nature. 2012;491:254-8）。大约2%的结直肠癌与先前存在的炎症有关，即结肠炎相关癌症，但大多数发生在没有潜在炎症性肠病的患者身上。结直肠癌通常遵循一种遗传途径，即随着肿瘤的出现和发展，腺瘤性大肠息肉病（APC）肿瘤抑制因子的丧失和β -连环蛋白的激活随后是K-Ras、PIK3CA和TP53的突变。然而，奇怪的是，结肠炎相关癌症特征的“炎症特征”基因在结直肠癌中也上调。此外，像大多数实体瘤一样，结直肠癌表现出免疫/炎症浸润，称为“肿瘤引发的炎症”。虽然浸润的CD4(+) T(H)1细胞和CD8（+）细胞毒性T细胞构成结直肠癌的阳性预后信号，但髓系细胞和T-辅助性白细胞介素(IL)-17产生（T(H)17）细胞促进肿瘤发生，并且I/II期结直肠癌的“T(H)17表达特征”与无病生存期的急剧下降有关。尽管其致病的重要性，负责肿瘤引起的炎症的出现机制知之甚少。许多上皮癌发生在微生物群落的近端，这些微生物群落通过上皮屏障与免疫细胞物理分离。我们在结直肠癌小鼠模型中研究了肿瘤引发炎症的机制，该模型与人类结直肠癌一样，表现出IL-23和IL-17的上调。在这里，我们发现IL-23信号传导促进肿瘤生长和进展，以及肿瘤IL-17反应的发展。IL-23主要由肿瘤相关的髓样细胞产生，这些细胞可能被微生物产物激活，这些微生物产物穿透肿瘤而不是邻近组织。早期和晚期结直肠肿瘤均表现出几种屏障蛋白的表达缺陷。我们提出，由结直肠癌引发的遗传病变引起的屏障恶化导致微生物产物侵入腺瘤，从而引发肿瘤引发的炎症，进而推动肿瘤生长。

Progress has been made in several of the aims of the project: The proinflammatory myeloid cell receptor TREM-1 controls Kupffer cell activation and development of hepatocellular carcinoma(Cancer Res. 2012 ;72:3977-86). Chronic inflammation drives liver cancer pathogenesis, invasion, and metastasis. Liver Kupffer cells have crucial roles in mediating the inflammatory processes that promote liver cancer, but the mechanistic basis for their contributions are not fully understood. Here we show that expression of the proinflammatory myeloid cell surface receptor TREM-1 expressed by Kupffer cells is a crucial factor in the development and progression of liver cancer. Deletion of the murine homolog Trem1 in mice attenuated hepatocellular carcinogenesis triggered by diethylnitrosamine (DEN). Trem1 deficiency attenuated Kupffer cell activation by downregulating transcription and protein expression of interleukin (IL)-6, IL-1beta, TNF, CCL2, and CXCL10. In addition, Trem1 ablation diminished activation of the p38, extracellular regulated kinase 1/2, JNK, mitogen-activated protein kinase, and NF-kB signaling pathways in Kupffer cells, resulting in diminished liver injury after DEN exposure. Adoptive transfer of wild-type Kupffer cells to Trem1-deficient mice complemented these defects and reversed unresponsiveness to DEN-induced liver injury and malignant development. Together, our findings offer causal evidence that TREM-1 is a pivotal determinant of Kupffer cell activation in liver carcinogenesis, deepening mechanistic insights into how chronic inflammation underpins the development and progression of liver cancer. NK cell-derived interferon-gamma orchestrates cellular dynamics and the differentiation of monocytes into dendritic cells at the site of infection Innate resistance and pro-inflammatory cytokines in carcinogenesis (Immunity. 2012;36:1047-59). Dendritic cells (DCs), monocyte and/or macrophages initiate host-protective immune responses to intracellular pathogens in part through interleukin-12 (IL-12) production, although the relative contribution of tissue resident versus recruited cells has been unclear. Here we showed that after intraperitoneal infection with Toxoplasma gondii cysts, resident mononuclear phagocytes are replaced by circulating monocytes that differentiate in situ into inflammatory DCs (moDCs) and F4/80+ macrophages. Importantly, NK cell-derived interferon-gamma (IFN-gamma) was required for both the loss of resident mononuclear phagocytes and the local differentiation of monocytes into macrophages and moDCs. This newly generated moDC population and not the resident DCs (or macrophages) served as the major source of IL-12 at the site of infection. Thus, NK cell-derived IFN-gamma is important in both regulating inflammatory cell dynamics and in driving the local differentiation of monocytes into the cells required for initiating the immune response to an important intracellular pathogen. A very extensive investigation has been initiated to study the role of inflammatory receptors and cytokines in skin and colon chemical carcinogenesis. Signaling through the adaptor protein MyD88 promotes carcinogenesis in several cancer models. In contrast, MyD88 signaling has a protective role in the development of azoxymethane (AOM)/ dextran sodium sulfate (DSS) colitis-associated cancer (CAC). The inability of Myd88-/- mice to heal ulcers generated upon injury creates an altered inflammatory environment that induces early alterations in expression of genes encoding pro-inflammatory factors as well as pathways regulating cell proliferation, apoptosis, and DNA repair resulting in a dramatic increase in adenoma formation and progression to infiltrating adenocarcinomas with frequent clonal mutations in the beta-catenin gene. This study revealed a previously unknown level of complexity surrounding MyD88 activities downstream of different receptors that impact tissue homeostasis and carcinogenesis. IL-1R-MyD88 signaling in keratinocyte transformation and carcinogenesis (J Exp Med. 2012;209:1689-702 ). Constitutively active RAS plays a central role in the development of human cancer and is sufficient to induce tumors in two-stage skin carcinogenesis. RAS-mediated tumor formation is commonly associated with up-regulation of cytokines and chemokines that mediate an inflammatory response considered relevant to oncogenesis. In this study, we report that mice lacking IL-1R or MyD88 are less sensitive to topical skin carcinogenesis than their respective wild-type (WT) controls. MyD88(-/-) or IL-1R(-/-) keratinocytes expressing oncogenic RAS are hyperproliferative and fail to up-regulate proinflammatory genes or down-regulate differentiation markers characteristic of RAS-expressing WT keratinocytes. Although RAS-expressing MyD88(-/-) keratinocytes form only a few small tumors in orthotopic grafts, IL-1R-deficient RAS-expressing keratinocytes retain the ability to form tumors in orthotopic grafts. Using both genetic and pharmacological approaches, we find that the differentiation and proinflammatory effects of oncogenic RAS in keratinocytes require the establishment of an autocrine loop through IL-1alpha, IL-1R, and MyD88 leading to phosphorylation of IkBalpha and NF-kB activation. Blocking IL-1alpha-mediated NF-kB activation in RAS-expressing WT keratinocytes reverses the differentiation defect and inhibits proinflammatory gene expression. Collectively, these results demonstrate that MyD88 exerts a cell-intrinsic function in RAS-mediated transformation of keratinocytes. Adenoma-linked barrier defects and microbial products drive IL-23/IL-17-mediated tumour growth (Nature. 2012;491:254-8). Approximately 2% of colorectal cancer is linked to pre-existing inflammation known as colitis-associated cancer, but most develops in patients without underlying inflammatory bowel disease. Colorectal cancer often follows a genetic pathway whereby loss of the adenomatous polyposis coli (APC) tumour suppressor and activation of beta-catenin are followed by mutations in K-Ras, PIK3CA and TP53, as the tumour emerges and progresses. Curiously, however, 'inflammatory signature' genes characteristic of colitis-associated cancer are also upregulated in colorectal cancer. Further, like most solid tumours, colorectal cancer exhibits immune/inflammatory infiltrates, referred to as 'tumour-elicited inflammation'. Although infiltrating CD4(+) T(H)1 cells and CD8(+) cytotoxic T cells constitute a positive prognostic sign in colorectal cancer, myeloid cells and T-helper interleukin (IL)-17-producing (T(H)17) cells promote tumorigenesis, and a 'T(H)17 expression signature' in stage I/II colorectal cancer is associated with a drastic decrease in disease-free survival. Despite its pathogenic importance, the mechanisms responsible for the appearance of tumour-elicited inflammation are poorly understood. Many epithelial cancers develop proximally to microbial communities, which are physically separated from immune cells by an epithelial barrier. We investigated mechanisms responsible for tumour-elicited inflammation in a mouse model of colorectal tumorigenesis, which, like human colorectal cancer, exhibits upregulation of IL-23 and IL-17. Here we show that IL-23 signalling promotes tumour growth and progression, and development of a tumoural IL-17 response. IL-23 is mainly produced by tumour-associated myeloid cells that are likely to be activated by microbial products, which penetrate the tumours but not adjacent tissue. Both early and late colorectal neoplasms exhibit defective expression of several barrier proteins. We propose that barrier deterioration induced by colorectal-cancer-initiating genetic lesions results in adenoma invasion by microbial products that trigger tumour-elicited inflammation, which in turn drives tumour growth.