肝干细胞的可塑性和分化机理的研究进展

对肝干细胞的可塑性、多向分化潜能、分化机理及其与肝癌发病机制的关系等方面进行综述.肝干细胞是一类具有自我更新能力和多向分化潜能的细胞. 在不同的条件下,肝干细胞可分化为肝细胞、胆上皮细胞、胰腺细胞和肠上皮细胞. 肝干细胞的分化涉及微环境、细胞因子和细胞外基质等多种调控因素. 肝干细胞分化为成熟肝细胞受多种转录因子和信号通路的调节,其分化异常有可能诱发形成肝细胞癌.     

综述: 肿瘤干细胞微环境与靶向干预策略

肿瘤干细胞具有自我更新和可塑性的潜能,能够维持肿瘤生长和异质性的能力．肿瘤干细胞是肿瘤产生、转移、耐药和复发的根源,肿瘤干细胞学说逐渐被肿瘤研究者所接受,因此,对肿瘤干细胞的深入理解有重大的科学和临床意义．肿瘤干细胞的微环境是肿瘤微环境的组成部分,包括细胞-细胞接触、分泌型因子等．肿瘤非干细胞和肿瘤干细胞本身都可以作为肿瘤干细胞的微环境．肿瘤干细胞的微环境可以维持肿瘤干细胞的可塑性,保护肿瘤干细胞免受免疫系统攻击,也可以促进其转移．肿瘤干细胞对其微环境的塑造、肿瘤干细胞的微环境对肿瘤干细胞自我更新的影响,以及针对肿瘤干细胞微环境的靶向干预等问题,已成为肿瘤干细胞研究的前沿问题．本文就肿瘤干细胞的发现、自我更新维持机制、肿瘤干细胞的微环境,及其肿瘤干细胞及微环境的干预策略等研究进展进行了综述．     

肝细胞癌复发转移机制的研究进展

复发转移是影响肝细胞癌患者治疗疗效和长期生存的最主要因素,探讨肝细胞癌复发转移的机制,寻找早期诊断复发转移、判断患者预后的生物标记和干预治疗的靶点,已成为当今肝细胞癌研究的热点与难点。本文就其复发转移部分机制如microRNA、CD147分子、肿瘤干细胞以及肿瘤微环境等几方面的研究进展进行综述。     

凋亡诱导因子AIF在肝癌组织中的表达及临床意义

目的：探讨凋亡诱导因子（AIF）在肝细胞癌组织中的表达及其临床意义。方法：采用免疫组织化学Envision法检测75例肝细胞癌组织及其相应癌旁肝组织、30例正常肝组织中AIF的表达,并分析其表达与肝细胞癌临床病理因素的相关性。结果：肝癌组织中AIF阳性表达率明显高于癌旁组织及正常肝组织,差异均具有统计学意义（P〈0.01）。AIF在肝癌组织中的表达仅与病理分级密切相关（P〈0.01）,而与年龄、性别、肿瘤大小、临床分期、肿瘤数目、有无肿瘤包膜和有无淋巴结转移、有无门静脉癌栓均无关。结论：AIF表达可能参与了肝癌的发生和发展过程。     

乳腺癌微环境中癌相关成纤维细胞活化机制的研究进展

在乳腺癌微环境中,癌相关成纤维细胞(cancer associated fibroblasts,CAFs)是肿瘤间质细胞的主要组分。大量研究证实CAFs可通过分泌多种细胞因子或细胞直接接触等方式调节乳腺癌细胞生长、决定乳腺癌细胞侵袭和转移能力,影响乳腺癌组织血管和淋巴管生成、ECM重塑、炎症反应和肿瘤微环境重编程等过程,影响治疗结果。随着研究的深入,众多研究者提出CAFs活化是其能够在肿瘤演进过程中发挥作用的关键。然而,目前关于乳腺癌微环境中CAFs活化机制尚未明确。该文将围绕CAFs活化特征、活化机制以及CAFs对乳腺癌的影响进行综述。     

肝细胞在HBx刺激和低氧压力时表达IL-2

肝细胞肝癌有极端坏的预后,主要归因于它的高转移性复发．我们曾经报道过对于乙型肝炎相关性肝癌患者,癌周组织的白介素2 (IL-2)水平越高就倾向于有更低的肝内转移复发率,而且IL-2的免疫组化显示主要着色于癌周的肝细胞．然而,是否肝细胞能在体外表达IL-2以及其内在机制仍未被揭示．本研究里,比较了有和没有肝炎病史的肝癌患者的癌周组织IL-2表达水平,然后在永生化的成人肝细胞THLE-2里过表达了乙型肝炎病毒x蛋白(HBx),并用过氧化氢处理模拟氧压力微环境．实验证实肝细胞在HBx刺激和低氧压力同时存在下能通过MAP3K7/NF-κB通路表达IL-2．研究结果提示靶向调节微环境氧化压力为预防和治疗乙肝相关性肝癌的转移复发提供了新的方向．     

大鼠肝癌发生过程中增殖细胞核抗原（PCNA／Cyclin）的表达

应用免疫组织化学的ＡＢＣ法,对二乙基亚硝胺（ＤＥＮ）诱发大鼠发生过程中增殖细胞核抗原在肝组织中的表达进行了系统观察。结果显示：正常大鼠肝组织中仅见极少数ＰＣＮＡ阳性肝细胞,阳性率为０．０８％,随着诱癌进程发展,大鼠肝组织中ＰＣＮＡ阳性肝细胞逐渐增多,诱癌第４、８、１２周,大鼠肝组织中ＰＣＮＡ阳性肝细胞百分率分别为１．６％、３．８％、１６．２％,诱癌晚期癌结节内大部分肝癌细胞里ＰＣＮＡ阳性表达,阳性率为８０．６％。本研究结果表明原位检测ＰＣＮＡ表达比传统依据形态学分化程度来判断肿瘤发生可能性更为客观、可靠。     

影响肝切除术后行TACE患者预后因素的分析

目的：对原发性肝细胞肝癌（HCC）肝部分切除术后行经肝动脉化疗栓塞（TACE）的病人和未行TACE病人影响其预后的多种因素进行分析和评价,为肝切除术后是否行TACE治疗寻找筛选条件。方法：对我院2003～2008年期间在我院肝胆外科行原发性肝细胞肝癌手术治疗221例（术后介入治疗103例,术后非介入治疗118例）患者进行全面随访了解患者的预后情况,分别对术后接受介入治疗和非介入治疗两组通过Kaplan-Meier及COX回归分析影响预后的因素,包括：年龄、性别、血清HBsAg、肿瘤直径、肿瘤大体分型、有无癌栓形成,肿瘤分期（TNM）共7项指标。结果：在1年生存期内介入治疗组中的性别、年龄、血清HBsAg、肿瘤直径、肿瘤大体分型无统计学意义（p〉0.05）,有无癌栓形成及肿瘤分期有意义（p〈0.05）;非介入组内年龄、性别、血清HBsAg无统计学意义,肿瘤直径、肿瘤大体分型、有无癌栓形成,肿瘤分期有意义;在3年生存期内介入治疗组中的以上指标无统计学意义,而非介入组在肿瘤直径、有癌栓形成及肿瘤分期方面与统计学意义。结论：对于肿瘤直径〉5cm及术后病理证实为低分化的患者给予积极TACE治疗可明显提高近期生存率。     

肝细胞癌及相关病变的计算机图像定量分析

为研究肝炎、肝硬变与肝细胞癌的关系,利用自动图像分析仪对６４例肝炎、肝硬变、癌旁肝硬变、肝细胞癌和正常肝组织进行了十三项参数的形态定量研究。结果：大多数参数随病变的发展而呈规律性变化,癌旁肝硬变的多数参数介于不伴肝癌的肝硬变与肝细胞癌之间。提示：（１）慢活肝、肝硬变与肝细胞癌密切相关;（２）癌旁肝硬变不同于不伴肝癌的肝硬变,与肝细胞癌的关系更密切。利用逐步判别分析选择出六项参数建立判别函数方程,回代正确率为９８．２％。     

MDM2在原发性肝细胞癌中的表达

目的检测MDM2蛋白及其mRNA在原发性肝细胞癌中的表达,探讨MDM2在原发性肝细胞癌发生发展中作用及意义.方法采用免疫组织化学、原位分子杂交和细胞图像分析技术,检测肝细胞癌组织及其对应癌旁肝组织(各20例),正常肝组织(5例)中MDM2蛋白及其mRNA 表达情况.结果在肝细胞癌组织、癌旁肝组织和正常肝组织中,MDM2蛋白免疫组织化学阳性反应颗粒的平均光密度分别为:0.404±0.105, 0.302±0.067, 0.087±0.034.肝细胞癌组织与癌旁肝组织、正常肝组织相比,差异均有显著性意义(P<0.05).MDM2 mRNA在肝细胞癌组织中呈阳性表达,而癌旁肝组织及正常肝组织均呈阴性.结论 MDM2过度表达在原发性肝细胞癌的发生发展过程中可能发挥了重要作用.     

Components of the hepatocellular carcinoma microenvironment and their role in tumor progression

This review summarizes recently published data on the mechanisms of tumor cell interaction with the tumor microenvironment. Tumor stroma influences the processes of hepatocarcinogenesis, epithelial-to-mesenchymal transition, invasion, and metastasis. The tumor microenvironment includes both cellular and noncellular components. Main cellular components of hepatocellular carcinoma (HCC) stroma are tumor-associated fibroblasts, hepatic stellate cells, immune cells, and endothelial cells that produce extracellular components of tumor microenvironment such as extracellular matrix, various proteins, proteolytic enzymes, growth factors, and cytokines. The noncellular components of the stroma modulate signaling pathways in tumor cells and stimulate invasion and metastasis. The tumor microenvironment composition and organization can serve as prognostic factors in HCC pathogenesis. Current approaches in HCC targeted therapy are aimed at creating efficient strategies for interrupting tumor interactions with the stroma. Recent data on the composition and role of the microenvironment in HCC pathogenesis, as well as new developments in antitumor drug design are discussed.     

Turning Hepatic Cancer Stem Cells Inside Out – A Deeper Understanding through Multiple Perspectives

Hepatocellular carcinoma (HCC), a highly malignant disease and the third leading cause of all cancer mortalities worldwide, often responses poorly to current treatments and results in dismal outcomes due to frequent chemoresistance and tumor relapse. The heterogeneity of HCC is an important attribute of the disease. It is the outcome of many factors, including the cross-talk between tumor cells within the tumor microenvironment and the acquisition and accumulation of genetic and epigenetic alterations in tumor cells. In addition, there is accumulating evidence in recent years to show that the malignancy of HCC can be attributed partly to the presence of cancer stem cell (CSC). CSCs are capable to self-renew, differentiate and initiate tumor formation. The regulation of the stem cell-like properties by several important signaling pathways have been found to endow the tumor cells with an increased level of tumorigenicity, chemoresistance, and metastatic ability. In this review, we will discuss the recent findings on hepatic CSCs, with special emphasis on their putative origins, relationship with hepatitis viruses, regulatory signaling networks, tumor microenvironment, and how these factors control the stemness of hepatic CSCs. We will also discuss some novel therapeutic strategies targeted at hepatic CSCs for combating HCC and perspectives of future investigation.     

SIRT7琥珀酰化修饰对肝癌生存、免疫浸润及预后的相关性分析

摘要 目的：探究SIRT7基因琥珀酰化修饰对肝癌患者的生存、免疫浸润及预后的相关性分析。方法：采用生物信息分析法对SIRT7在肝癌组织中的表达情况及其对肝癌患者预后的影响进行分析；采用蛋白免疫印迹法（Western blot）检测其转染效果。结果：（1）生物信息分析结果显示：SIRT7在多种肿瘤（包括肝癌）组织中呈高表达（P<0.05）；SIRT7的表达与肿瘤的生存曲线相关（P<0.05）；肝癌患者的SIRT7相对表达量与其预后相关，高表达组肝癌患者的总生存情况（P=0.017）和无进展生存情况较低表达组缩短（P=0.004）；免疫浸润和肿瘤微环境分析结果显示，SIRT7表达水平与多数免疫细胞浸润水平、肿瘤微环境(ESTIMATES core)均有明显负相关。（2）Western blot显示，SIRT7在肝癌细胞中表达高于正常细胞。因此，SIRT7 可作为肝癌的潜在预后标志物。结论：SIRT7表达水平与肝癌(HCC)患者的预后、免疫细胞浸润性、肿瘤微环境免疫细胞和基质细胞浸润等相关。     

Encapsulated human hepatocellular carcinoma cells by alginate gel beads as an in vitro metastasis model

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and often forms metastases, which are the most important prognostic factors. For further elucidation of the mechanism underlying the progression and metastasis of HCC, a culture system mimicking the in vivo tumor microenvironment is needed. In this study, we investigated the metastatic ability of HCC cells cultured within alginate gel (ALG) beads. In the culture system, HCC cells formed spheroids by proliferation and maintained in nuclear abnormalities. The gene and protein expression of metastasis-related molecules was increased in ALG beads, compared with the traditional adhesion culture. Furthermore, several gene expression levels in ALG bead culture system were even closer to liver cancer tissues. More importantly, in vitro invasion assay showed that the invasion cells derived from ALG beads was 7.8-fold higher than adhesion cells. Our results indicated that the in vitro three-dimensional (3D) model based on ALG beads increased metastatic ability compared with adhesion culture, even partly mimicked the in vivo tumor tissues. Moreover, due to the controllable preparation conditions, steady characteristics and production at large-scale, the 3D ALG bead model would become an important tool used in the high-throughput screening of anti-metastasis drugs and the metastatic mechanism research.     

Activated Human Hepatic Stellate Cells Promote Growth of Human Hepatocellular Carcinoma in a Subcutaneous Xenograft Nude Mouse Model

Tumor cell microenvironment defines cancer development, also in hepatocellular carcinoma (HCC). Hepatic stellate cells (HSCs) are believed to be the key contributors to tumor microenvironment in HCC, yet their precise role in cancer progression is still unclear. The aim of this study was to determine the effect of human HSCs on progression of HCC using a subcutaneous xenograft nude mouse model. Nude mice were stratified to receive subcutaneous injections of human HCC cell line HepG2 and human HSC line LX-2 (HepG2 + LX-2), HepG2 alone, LX-2 alone, or phosphate-buffered saline. Tumor growth was assessed by measuring tumor size. After 30 days, final tumor size, weight, and histology were assessed. Compared with mice that were only injected HepG2 cells, mice injected with HepG2 + LX-2 exhibited more rapid tumor growth, increased tumor size and weight, higher tumor cell numbers due to increased proliferation and reduced apoptosis, increased fibrotic bands containing LX-2 cells, and increased tumor angiogenesis. In conclusion, HSCs play a significant role in promotion of HCC growth.     

血小板反应蛋白4通过诱导肿瘤相关巨噬细胞M2型极化促进肝癌细胞转移

血小板反应蛋白4 (thrombospondin 4, THBS4) 属于THBS家族成员,是细胞外基质分泌的蛋白质,参与调控细胞增殖、黏附及血管生成等多种生理过程。近来研究表明,机体在炎症刺激下加速产生THBS4并诱导巨噬细胞粘附与积累。我们的前期研究证实,THBS4在肝癌(hepatocellular carcinoma,HCC)中发挥促癌作用,但THBS4对肝癌免疫微环境的影响尚不明确。本文旨在分析THBS4通过诱导肿瘤相关巨噬细胞M2型极化,促进肝癌细胞转移的作用。通过肝癌条件培养基(HCC conditioned medium,HCM)模拟肿瘤微环境,发现在HCM作用下巨噬细胞中THBS4表达呈时间依赖性升高(P＜0.05);下调THBS4促使M1型巨噬细胞标志物IL-1β、CD86的表达升高(P＜0.01),而M2型标志物 IL-10和CD206表达降低(P＜0.01)。进一步通过Transwell共培养实验检测THBS4诱导的M2型巨噬细胞对肝癌转移的影响。将下调THBS4的M2型巨噬细胞(M2-TAMs)与HepG2肝癌细胞进行共培养。结果显示,下调THBS4的M2-TAMs明显抑制了HepG2细胞的侵袭和迁移能力(P均＜0.01)。综上所述,肿瘤微环境促进巨噬细胞中THBS4表达,THBS4可能通过诱导巨噬细胞M2型极化促进肝癌细胞侵袭转移。本文为探究THBS4诱导肝癌免疫微环境的建立提供了一些新的实验依据。     

Survival prediction and response to immune checkpoint inhibitors: A prognostic immune signature for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers all over the world. Several studies have explored if immune-related genes and tumor immune microenvironment could play roles in HCC prognoses. This study is aimed at developing a prognostic signature of HCC based on immune-related genes or tumor immune microenvironment to predict survival and response to immune checkpoint inhibitors (ICIs). We constructed a prognostic signature using bioinformatics method and validated its predictive capability. The mechanisms of the signature prediction were explored with The Cancer Immunome Atlas (TCIA) and mutation analysis. We also explored the association between the signature and immunophenoscore (IPS), which is the marker of ICIs response. A 6 immune-related-gene (6-IRG) signature was developed. It was revealed in a multivariate analysis that the 6-IRG signature was an independent prognostic factor of overall survival and progression-free interval among HCC patients. In the high-risk group of 6-IRG signature score, macrophage M0 cells and regulatory T cells, which are observed associated with poor overall survival in our study, were higher. The low-risk group had a higher IPS, which meant a better response to ICIs. Taken together, we constructed a reliable 6-IRG signature for prediction of survival and response to ICIs. The signature needs further testing for clinical application.