Suppression of murine breast cancer metastasis by selective inhibition of CXCR4 by synthetic polypeptide derived from viral macrophage inflammatory protein II

Stromal cell-derived factor-1 and its receptor CXC chemokine receptor-4 (CXCR4) have been implicated in breast cancer metastasis. A significant association between HER2 and CXCR4 expression has been observed in human breast tumor tissues, and overexpression of CXCR4 is essential for HER2-mediated tumor metastasis. Moreover, CXCR4 expression is low in normal breast tissues and high in malignant tumors, suggesting that a blockade of CXCR4 may limit tumor metastasis. The present study investigated the action of a synthetic antagonist 21-mer peptide derived from viral macrophage inflammatory protein II against CXCR4 (NT21MP) in inhibiting metastasis in vitro and in vivo. The results showed that chemotaxis of SKBR3 cells toward SDF-1α was reduced by NT21MP in a dose-dependent manner (P < 0.05). NT21MP inhibited tumor growth at 500 μg/kg and in combination with Herceptin, the anti-HER2 antibody. The in vivo metastatic assay showed that NT21MP significantly inhibited pulmonary metastasis, and the number of metastatic tumor nodes on the surface of the lung was greatly decreased. Compared with the saline-treated control group, PCNA expression was dose-dependently decreased by NT21MP, the percentage of apoptotic cells was increased, and CXCR4 mRNA and protein expression were downregulated. In conclusion, NT21MP inhibits cellular prolifer-ation, promotes apoptosis by downregulating CXCR4 expression, and suppresses the progression of primary and metastatic tumors. CXCR4 may be a useful therapeutic target for breast cancer, and NT21MP may serve as a potential target drug for the treatment of breast cancer metastasis.     

CXCR4拮抗剂在肿瘤治疗中的应用

G蛋白偶联趋化因子受体CXCR4在癌细胞表面广泛表达,癌细胞易转移部位的基质细胞组成型分泌CXCR4的配体——基质细胞衍生因子-1(SDF-1/CXCL12),表达CXCR4的癌细胞在CXCR4/CXCL12轴的调控下沿CXCL12浓度梯度进行转运和归巢,转移的癌细胞在CXCL12作用下与基质细胞紧密联系而获得药物抗性.CXCR4的拮抗剂,比如AMD3100,T140类似物和本课题组开发的SDF-1βP2G,能打断癌细胞与基质细胞的相互作用,动员癌细胞离开对其具保护作用的微环境从而进入血液循环系统,使癌细胞对传统药物的敏感性增加.因此,靶向CXCR4/CXCL12轴的CXCR4拮抗剂联合化疗在探索肿瘤患者治疗方面是一个新颖的,富有吸引力的方法.     

Chemokine receptor CXCR4 downregulated by von Hippel-Lindau tumour suppressor pVHL

Organ-specific metastasis is governed, in part, by interactions between chemokine receptors on cancer cells and matching chemokines in target organs. For example, malignant breast cancer cells express the chemokine receptor CXCR4 and commonly metastasize to organs that are an abundant source of the CXCR4-specific ligand stromal cell-derived factor-1alpha (ref. 1). It is still uncertain how an evolving tumour cell is reprogrammed to express CXCR4, thus implementing the tendency to metastasize to specific organs. Here we show that the von Hippel-Lindau tumour suppressor protein pVHL negatively regulates CXCR4 expression owing to its capacity to target hypoxia-inducible factor (HIF) for degradation under normoxic conditions. This process is suppressed under hypoxic conditions, resulting in HIF-dependent CXCR4 activation. An analysis of clear cell renal carcinoma that manifests mutation of the VHL gene in most cases revealed an association of strong CXCR4 expression with poor tumour-specific survival. These results suggest a mechanism for CXCR4 activation during tumour cell evolution and imply that VHL inactivation acquired by incipient tumour cells early in tumorigenesis confers not only a selective survival advantage but also the tendency to home to selected organs.     

低氧条件下巨噬细胞分泌CCL22促进三阴乳腺癌转移

三阴乳腺癌(Triple Negative Breast Cancer, TNBC)是乳腺癌中恶性程度最高的一种亚型，表现为很高的转移潜能。巨噬细胞，即肿瘤相关巨噬细胞(Tumor-Associated Macrophages, TAM)，在促进TNBC转移中起了重要作用。乳腺癌作为一种实体肿瘤，往往处于缺氧环境中。低氧环境能够促进癌细胞的转移，然而低氧环境中巨噬细胞在促进肿瘤转移中的作用仍然不清楚。在该研究中，THP1细胞被诱导成TAM，经过缺氧培养后，通过Transwell实验检测其促进三阴乳腺癌细胞BT-549和MDA-MB-231的细胞迁移能力；通过尾静脉注射，将MDA-MB-231细胞移植于祼鼠体内，CT扫描，分析了TAM促进TNBC细胞的器官转移能力；通过ELISA实验检测低氧对TAM分泌的肿瘤转移相关因子的影响，通过GDSC在线软件分析了CCL22受体CCR4和其他CCR在乳腺癌组织与正常组织中表达的差异。结果表明低氧条件下巨噬细胞通过分泌CCL22的表达来促进三阴乳腺癌细胞迁移:经过缺氧培养后的TAM显著增强了TNBC细胞迁移能力，以及促进癌细胞在体内向肺转移；低氧诱导TAM分泌CCL22；CCL22受体CCR4在乳腺癌组织中的表达显著高于在正常组织中的。     

A microRNA regulon that mediates endothelial recruitment and metastasis by cancer cells

Metastatic progression of cancer is a complex and clinically daunting process. We previously identified a set of human microRNAs (miRNAs) that robustly suppress breast cancer metastasis to lung and bone and which display expression levels that predict human metastasis. Although these findings revealed miRNAs as suppressors of cell-autonomous metastatic phenotypes, the roles of non-coding RNAs in non-cell-autonomous cancer progression processes remain unknown. Here we reveal that endogenous miR-126, an miRNA silenced in a variety of common human cancers, non-cell-autonomously regulates endothelial cell recruitment to metastatic breast cancer cells, in vitro and in vivo. It suppresses metastatic endothelial recruitment, metastatic angiogenesis and metastatic colonization through coordinate targeting of IGFBP2, PITPNC1 and MERTK--novel pro-angiogenic genes and biomarkers of human metastasis. Insulin-like growth factor binding protein 2 (IGFBP2) secreted by metastatic cells recruits endothelia by modulating IGF1-mediated activation of the IGF type-I receptor on endothelial cells; whereas c-Mer tyrosine kinase (MERTK) receptor cleaved from metastatic cells promotes endothelial recruitment by competitively antagonizing the binding of its ligand GAS6 to endothelial MERTK receptors. Co-injection of endothelial cells with breast cancer cells non-cell-autonomously rescues their miR-126-induced metastatic defect, revealing a novel and important role for endothelial interactions in metastatic initiation. Through loss-of-function and epistasis experiments, we delineate an miRNA regulatory network's individual components as novel and cell-extrinsic regulators of endothelial recruitment, angiogenesis and metastatic colonization. We also identify the IGFBP2/IGF1/IGF1R and GAS6/MERTK signalling pathways as regulators of cancer-mediated endothelial recruitment. Our work further reveals endothelial recruitment and endothelial interactions in the tumour microenvironment to be critical features of metastatic breast cancer.     

CCL2 recruits inflammatory monocytes to facilitate breast-tumour metastasis

Macrophages, which are abundant in the tumour microenvironment, enhance malignancy. At metastatic sites, a distinct population of metastasis-associated macrophages promotes the extravasation, seeding and persistent growth of tumour cells. Here we define the origin of these macrophages by showing that Gr1-positive inflammatory monocytes are preferentially recruited to pulmonary metastases but not to primary mammary tumours in mice. This process also occurs for human inflammatory monocytes in pulmonary metastases of human breast cancer cells. The recruitment of these inflammatory monocytes, which express CCR2 (the receptor for chemokine CCL2), as well as the subsequent recruitment of metastasis-associated macrophages and their interaction with metastasizing tumour cells, is dependent on CCL2 synthesized by both the tumour and the stroma. Inhibition of CCL2-CCR2 signalling blocks the recruitment of inflammatory monocytes, inhibits metastasis in vivo and prolongs the survival of tumour-bearing mice. Depletion of tumour-cell-derived CCL2 also inhibits metastatic seeding. Inflammatory monocytes promote the extravasation of tumour cells in a process that requires monocyte-derived vascular endothelial growth factor. CCL2 expression and macrophage infiltration are correlated with poor prognosis and metastatic disease in human breast cancer. Our data provide the mechanistic link between these two clinical associations and indicate new therapeutic targets for treating metastatic breast cancer.     

人肺癌裸鼠常位移植实验研究

将高转移人肺巨细胞癌和低转移人肺腺癌常位移植于裸鼠肺内,其移植成功率分别为74％和56％,肺内移植瘤仍保持人原发肿瘤的病理组织学形态,其肉眼类型可呈肺门肿块,周围结节和弥散浸润型,与人类原发肺癌亦相似,而与局限膨胀生长或较少浸润的裸鼠皮下移植瘤有明显区别。肺内常位移植瘤较广泛地浸润胸部脏器,特别应当指出的是低转移肺腺癌细胞肺内移植其淋巴结转移率可达56％,甚至高于该癌系在beige裸鼠体内的淋巴结转移率。说明常位移植有利于恶性肿瘤表达其浸润转移表型。常位移植之肿瘤生物学行为更接近人体内原发性肿瘤的生物学行为,将成为研究人类肿瘤特性和实验治疗的更为适宜的实验模型。研究裸鼠皮下移植瘤和常位移植瘤基因表达的差异亦将为肿瘤浸润转移分子生物学基础的揭示作出贡献     

Balanced responsiveness to chemoattractants from adjacent zones determines B-cell position

B lymphocytes re-circulate between B-cell-rich compartments (follicles or B zones) in secondary lymphoid organs, surveying for antigen. After antigen binding, B cells move to the boundary of B and T zones to interact with T-helper cells. Despite the importance of B--T-cell interactions for the induction of antibody responses, the mechanism causing B-cell movement to the T zone has not been defined. Here we show that antigen-engaged B cells have increased expression of CCR7, the receptor for the T-zone chemokines CCL19 and CCL21, and that they exhibit increased responsiveness to both chemoattractants. In mice lacking lymphoid CCL19 and CCL21 chemokines, or with B cells that lack CCR7, antigen engagement fails to cause movement to the T zone. Using retroviral-mediated gene transfer we demonstrate that increased expression of CCR7 is sufficient to direct B cells to the T zone. Reciprocally, overexpression of CXCR5, the receptor for the B-zone chemokine CXCL13, is sufficient to overcome antigen-induced B-cell movement to the T zone. These findings define the mechanism of B-cell relocalization in response to antigen, and establish that cell position in vivo can be determined by the balance of responsiveness to chemoattractants made in separate but adjacent zones.     

Regulation of cancer cell migration and bone metastasis by RANKL

Bone metastases are a frequent complication of many cancers that result in severe disease burden and pain. Since the late nineteenth century, it has been thought that the microenvironment of the local host tissue actively participates in the propensity of certain cancers to metastasize to specific organs, and that bone provides an especially fertile 'soil'. In the case of breast cancers, the local chemokine milieu is now emerging as an explanation for why these tumours preferentially metastasize to certain organs. However, as the inhibition of chemokine receptors in vivo only partially blocks metastatic behaviour, other factors must exist that regulate the preferential metastasis of breast cancer cells. Here we show that the cytokine RANKL (receptor activator of NF-kappaB ligand) triggers migration of human epithelial cancer cells and melanoma cells that express the receptor RANK. RANK is expressed on cancer cell lines and breast cancer cells in patients. In a mouse model of melanoma metastasis, in vivo neutralization of RANKL by osteoprotegerin results in complete protection from paralysis and a marked reduction in tumour burden in bones but not in other organs. Our data show that local differentiation factors such as RANKL have an important role in cell migration and the tissue-specific metastatic behaviour of cancer cells.     

Mesenchymal stem cells within tumour stroma promote breast cancer metastasis

Mesenchymal stem cells have been recently described to localize to breast carcinomas, where they integrate into the tumour-associated stroma. However, the involvement of mesenchymal stem cells (or their derivatives) in tumour pathophysiology has not been addressed. Here, we demonstrate that bone-marrow-derived human mesenchymal stem cells, when mixed with otherwise weakly metastatic human breast carcinoma cells, cause the cancer cells to increase their metastatic potency greatly when this cell mixture is introduced into a subcutaneous site and allowed to form a tumour xenograft. The breast cancer cells stimulate de novo secretion of the chemokine CCL5 (also called RANTES) from mesenchymal stem cells, which then acts in a paracrine fashion on the cancer cells to enhance their motility, invasion and metastasis. This enhanced metastatic ability is reversible and is dependent on CCL5 signalling through the chemokine receptor CCR5. Collectively, these data demonstrate that the tumour microenvironment facilitates metastatic spread by eliciting reversible changes in the phenotype of cancer cells.     

Strategy against micrometastasis of epithelial cancer: Detection and elimination

Tumor metastasis is generally agreed to be the major cause of cancer death. Over the last few years, studies of new diagnosis techniques and tumor immunotherapy have made great progress. Recent clinical studies on the occult metastases of breast, lung and colorectal cancer all suggested that the detection of micrometastases in bone marrow is prognostically important and provides substantial evidence of tumor dissemination. On the other hand, two kinds of the mAb-based immunotherapy have been approved for the treatment against epithelial cancer. Monoclonal antibody (mAb) 17-1A for colorectal carcinomas and mAb herceptin for breast cancer both have produced good curative effects. Potential therapeutics based on some antibodies with prominent antitumor activity also has shown obvious clinical effect. These studies indicate that detection of micrometastasis in circulatory system and immunotherapy by eliminating metastatic malignant cells suggested a new strategy against the metastatic cancer.     

三阴乳腺癌与基底细胞样乳腺癌病理形态和生物学特征探讨

目的探讨三阴乳腺癌(triple-negative breast cancer,TNBC)与基底细胞样乳腺癌(basal-likebreast cancer,BLBC)及非三阴乳腺癌(non triple-negative breast cancer,NTNBC)的关系及其形态、生物学特征。方法应用免疫组织化学(immunohistochemistry,IHC)方法对96例乳腺癌标本进行HER2、ER、PR蛋白的检查;应用FISH(fluorescent in situ hybridization)方法对3例HER2 IHC 3+及5例HER2 IHC 2+标本进行HER2基因扩增的检查;对22例TNBC进行了CK5/6或EGFR的检查。按照检查结果,将其分为TNBC、NTN-BC和BLBC,比较三者的病理形态及生物学特征。结果 NTNBC占72.92%(70/96),其组织学Ⅰ、Ⅱ及Ⅲ级的病例分别为28.57%(20/70)、57.14%(40/70)和14.29%(10/70),淋巴结转移率为44.44%(16/36);TN-BC占乳腺癌的27.08%(26/96),无组织学Ⅰ级病例,组织学Ⅱ及Ⅲ级的病例分别为53.85%,(14/26)及46.15%,(12/26)例,淋巴结转移率为61.11%(11/18);BLBC占TNBC的63.64%(14/22),同TNBC一样,无组织学Ⅰ级病例,Ⅱ、Ⅲ级的病例分别为57.14%(8/14)及42.86%(6/14),淋巴结转移率为55.56%(5/9)。TN-BC与BLBC低分化病例的比例以及淋巴结的转移率均高于NTNBC。3例HER2 IHC 3+的病例FISH检查结果同IHC,5例HER 2 IHC 2+标本FISH检查1例基因扩增,3例阴性,1例结果不确定。结论 TNBC与BLBC占乳腺癌1/4的比例,组织学多为中、低分化,浸润性生长,易发生淋巴结转移和复发,临床预后较差。虽然BLBC与TNBC大部分有重叠,但其具有独自的特异性,应成为独立的组织病理学类型。CK5/6或EGFR可用作从TNBC中筛选BLBC的指标。IHC 2+病例要做FISH检查,以正确指导治疗。     

CXCR7对HeLa细胞增殖、粘附和侵袭能力的影响

基质细胞衍生因子-1(SDF-1)在肿瘤侵袭、转移过程中起着重要的调控作用.此前认为SDF-1是通过其唯一受体CXCR4来起作用.近年来发现SDF-1还有另一作用受体——CXCR7,SDF-1/CXCR7在部分肿瘤侵袭转移过程中起重要作用,但其在宫颈癌HeLa细胞中的作用目前尚未明确.通过Western blotting检测HeLa细胞中CXCR4和CXCR7的表达,阻断CXCR4或CXCR7后,通过MTT法评价细胞增殖能力,细胞粘附实验评价细胞粘附能力,Transwell实验评价细胞侵袭能力.结果表明,CXCR4和CXCR7在HeLa细胞中表达.阻断CXCR4或CXCR7后,SDF-1诱导的HeLa细胞增殖、侵袭和与内皮细胞的粘附能力均被阻断.结果提示CXCR7在SDF-1诱导HeLa细胞增殖、侵袭和与内皮细胞的粘附过程中起着重要作用,将有望成为治疗宫颈癌转移的新靶点.     

新疆维、汉民族乳腺癌中P53和Ki-67蛋白表达及其意义

用免疫组化Envision法检测125例维、汉民族乳腺癌中P53及Ki-67蛋白的表达。结果表明，P53及Ki-67蛋白在乳腺癌中的阳性表达率明显高于非癌组织；且在浸润性导管癌中P53和Ki-67蛋白阳性表达与分级、转移呈正相关，与民族无关。随组织学分级增高，P53及Ki-67阳性表达增高。淋巴结转移者P53及Ki-67蛋白阳性表达明显高于无淋巴结转移者。提示P53和Ki-67蛋白阳性表达可能在乳腺良性病变恶性转化及乳腺癌的发生中具有重要作用，有可能成为临床预测预后的重要指标之一。     

PRL-3基因在前列腺癌组织中的表达分析

检测PRL-3在前列腺癌中的表达,探讨其与前列腺癌发生发展的关系。Westernblot、RT-PCR检测52例前列腺癌组织及其对应癌旁增生组织,12例阳性淋巴结相对表达水平,并分析其表达水平与临床病理学指标的关系。结果52例前列腺癌中PRL-3基因表达量较相应癌旁增生组织高,差异有统计学意义(p0.05),12例淋巴结转移灶PRL-3表达量明显高于原发肿瘤、阴性淋巴结及癌旁增生组织(p0.01)。PRL-3基因的表达水平与前列腺癌分化程度、淋巴结转移有关(p0.05),与年龄、家族史、血清PSA含量无关(p0.05)。说明PRL-3的表达与前列腺癌发生发展关系密切,PRL-3可作为前列腺癌诊断、治疗及预后判断过程中的一种较有价值的指标。     

Up—Regulation of CCR5 and CXCR4 Expression on Human Monocytes by Interferon Gamma

Chemokine receptors, mainly CCR5 and CXCR4, have been proved to be the important coreceptors in HIV-1 entry. HIV-1 disease progression is, in general, characterized by an initial predominance of CCR5 using macrophage tropic, non-syncytium-inducing (NSI) isolates, switching later to CXCR4 using T-cell tropic,syncytium-inducing (SI) isolates. How this shift occurs and how the shift can be controlled are still unclear.Since patients with rapid decline of T cell counts have constantly high levels of IFN-7 in the sera and lymphoidnodes, we investigated the influence of this cytokine on the expression of the HIV-1 coreceptors CCR5 and CXCR4 on the cell surfaces of human monocytic cell line U937 and promonocyte NB4. IFN-γ could intensively enhance the expression of both, while a low level of CCR5 expression was detected in two cell lines before stimulation. The results of semiquantitative RT-PCR also confirm the up-regulation. As the newly generated X4-strains have been demonstrated to be insensitive to chemokine in some reports, IFN-7 may play an important role in selecting CXCR4-used strains.     

胃癌前哨淋巴结导航手术的研究

目的探讨胃癌前哨淋巴结（SLN）活检技术在治疗胃癌疾病中的价值．方法通过使用亚甲蓝对40例患有胃癌疾病的患者行前哨淋巴结术中标识活检，术后进行常规HE病理和免疫组化检查，用统计学方法对结果进行分析，探讨术中注射亚甲蓝后前哨淋巴结的表达情况．结果在40例中有39例检出SLN，其检出率为97．5％．一共检出54枚淋巴结，平...     

Gene expression profiling predicts clinical outcome of breast cancer

Breast cancer patients with the same stage of disease can have markedly different treatment responses and overall outcome. The strongest predictors for metastases (for example, lymph node status and histological grade) fail to classify accurately breast tumours according to their clinical behaviour. Chemotherapy or hormonal therapy reduces the risk of distant metastases by approximately one-third; however, 70-80% of patients receiving this treatment would have survived without it. None of the signatures of breast cancer gene expression reported to date allow for patient-tailored therapy strategies. Here we used DNA microarray analysis on primary breast tumours of 117 young patients, and applied supervised classification to identify a gene expression signature strongly predictive of a short interval to distant metastases ('poor prognosis' signature) in patients without tumour cells in local lymph nodes at diagnosis (lymph node negative). In addition, we established a signature that identifies tumours of BRCA1 carriers. The poor prognosis signature consists of genes regulating cell cycle, invasion, metastasis and angiogenesis. This gene expression profile will outperform all currently used clinical parameters in predicting disease outcome. Our findings provide a strategy to select patients who would benefit from adjuvant therapy.