Microvesicles derived from activated platelets induce metastasis and angiogenesis in lung cancer

The role of platelets in tumor progression and metastasis has been recognized but the mechanism of their action remains unclear. Five human lung cancer cell lines (A549, CRL 2066, CRL 2062, HTB 183, HTB 177) and a murine Lewis lung carcinoma (LCC) cell line (for an in vivo model of metastasis) were used to investigate how platelet-derived microvesicles (PMV), which are circular fragments shed from the surface membranes of activated platelets, and exosomes released from platelet alpha-granules, could contribute to metastatic spread. We found that PMV transferred the platelet-derived integrin CD41 to most of the lung cancer cell lines tested and stimulated the phosphorylation of mitogen-activated protein kinase p42/44 and serine/threonine kinase as well as the expression of membrane type 1-matrix metalloproteinase (MT1-MMP). PMV chemoattracted 4 of the 5 cell lines, with the highly metastatic A549 cells exhibiting the strongest response. In A549 cells, PMV were shown to stimulate proliferation, upregulate cyclin D2 expression and increase trans-Matrigel chemoinvasion. Furthermore, in these cells, PMV stimulated mRNA expression for angiogenic factors such as MMP-9, vascular endothelial growth factor, interleukin-8 and hepatocyte growth factor, as well as adhesion to fibrinogen and human umbilical vein endothelial cells. Intravenous injection of murine PMV-covered LLC cells into syngeneic mice resulted in significantly more metastatic foci in their lungs and LLC cells in bone marrow than in control animals injected with LCC cells not covered with PMV. Based on these findings, we suggest that PMV play an important role in tumor progression/metastasis and angiogenesis in lung cancer.     

基质金属蛋白酶及其抑制剂与肺癌的侵袭和转移

基质金属蛋白酶(MMPs)家族是细胞外基质降解过程中的重要酶类,与多种病理过程尤其是肿瘤侵袭和转移有密切关系,因此成为肿瘤治疗的新靶点,本文就MMPs、TIMPs的生物学作用,与肺癌侵袭转移的关系及MMP合成抑制剂的开发研究情况等方面做一综述.     

The role of matrix metalloproteinases in tumor angiogenesis and tumor metastasis

Although a considerable amount of effort has been placed on discovering the etiologies of cancer, the majority of the basic cancer research existing today has focused on understanding the molecular mechanism of tumor formation and metastasis. Metastatic spread of tumors continues to be a major obstacle to successful treatment of malignant tumors. Approximately 30% of those patients diagnosed with a solid tumor have a clinically detectable metastasis and for the remaining 70%, metastases are continually being formed throughout the life of the tumor. Even after the tumor is excised, the threat of death is attributable to the metastasis that may occur through the remaining tumor cells. In addition, treating the metastasis often proves futile since metastasis often vary in size, composition, and anatomical location. New treatments blocking the formation of metastasis will provide greater chances of survival for cancer patients. One family of enzymes that has been shown over the years to play a role in tumor progression is the matrix metalloproteinase (MMP) family. The main function of MMPs, also known as matrixins, is degradation of the extracellular matrix physiologic function involving MMPs include wound healing, bone resorption and mammary involution. MMPs, however, also contribute to pathological conditions including rheumatoid arthritis, coronary artery disease, and cancer. Tumor cells are believed to utilize the matrix degrading capability of these enzymes to spread to distant sites. In addition, MMPs also are thought to promote the growth of these tumor cells once they have metastasized. This review will discuss the role of MMPs and their inhibitors in tumor invasion, angiogenesis and metastasis with special emphasis on the gelatinases, MMP-2 and MMP-9.     

EGFR-targeted therapy alters the tumor microenvironment in EGFR-driven lung tumors: Implications for combination therapies

Immune checkpoint inhibitors targeting the programmed cell death receptor/ligand 1 (PD-1/PD-L1) pathway have profoundly improved the clinical management of non-small-cell lung cancer (NSCLC). Nevertheless, the superiority of single-agent PD-1/PD-L1 inhibitors in pretreated EGFR mutant patients has turned out to be moderate. One proposed mechanism for poor response to immune checkpoint inhibitors is an immunosuppressive tumor microenvironment. Therefore, we utilized two autochthonous EGFR-driven lung tumor models to investigate dynamic microenvironmental responses to EGFR-TKI treatment. We observed that at an early stage, sensitive EGFR-TKIs caused obvious tumor shrinkage accompanied by increased cytotoxic CD8⁺ T cells and dendritic cells, eradication of Foxp3⁺ Tregs, and inhibition of M2-like polarization of macrophages. However, the tumor microenvironmental changes that may be most beneficial for combination treatment with immune-mediated anticancer approaches were only temporary and disappeared as treatment continued. Meanwhile, the level of myeloid-derived suppressor cells (MDSCs), particularly mononuclear MDSCs, was consistently elevated throughout the treatment. Analysis of inflammatory factors in serum showed that EGFR-TKIs increased the levels of IL-10 and CCL-2. Our study systematically analyzed dynamic changes in tumor microenvironments responding to EGFR-TKIs in vivo. The results have implications for combination therapy using EGFR-TKIs. The optimal sequence of the treatment and strategies that modulate the tumor microenvironment to a state that may favor antitumor immune responses need to be considered when designing clinical trials.     

基质金属蛋白酶与肿瘤微环境的关系

基质金属蛋白酶(MMP)及其抑制剂组织金属蛋白酶抑制剂(TIMP)对细胞外基质(ECM)的变化共同调节肿瘤微环境.MMP可控制肿瘤演进过程中多种蛋白酶的表达.成纤维细胞、炎症细胞和上皮细胞等宿主细胞中MMP的变化与肿瘤形成呈正或负相关.     

免疫微环境促进肿瘤发生发展的机制研究进展

机体免疫有宿主保护和肿瘤促进双重作用免疫微环境对肿瘤的促进作用知之甚少。研究发现本文讨论免疫微环境可直接或间接地影响肿瘤的发生发展,其机制。其机制包括促进肿瘤血管生成、改变肿瘤的生物学特性、筛选适应微环境的肿瘤细胞存活或建立适宜的肿瘤微环境促进肿瘤进展,甚至可以调节肿瘤干细胞活性。基于免疫微环境在肿瘤发生发展中的重要作用,免疫治疗成为一种重要的抗肿瘤治疗手段,而探索免疫治疗和细胞毒药物或分子靶向药物联合的多模式治疗可能是未来肿瘤免疫治疗的方向。     

Interleukin 6 trigged ataxia-telangiectasia mutated activation facilitates lung cancer metastasis via MMP-3/MMP-13 up-regulation

Our previous studies show that the phosphorylation of ataxia-telangiectasia mutated (ATM) induced by interleukin 6 (IL-6) treatment contributes to multidrug resistance formation in lung cancer cells, but the exact role of ATM activation in IL-6 increased metastasis is still elusive. In the present study, matrix metalloproteinase-3 (MMP-3) and MMP-13 were firstly demonstrated to be involved in IL-6 correlated cell migration. Secondly, IL-6 treatment not only increased MMP-3/MMP-13 expression but also augmented its activities. Thirdly, the inhibition of ATM phosphorylation efficiently abolished IL-6 up-regulating MMP-3/MMP-13 expression and increasing abilities of cell migration. Most importantly, the in vivo test showed that the inhibition of ATM abrogate the effect of IL-6 on lung cancer metastasis via MMP-3/MMP-13 down-regulation. Taken together, these findings demonstrate that IL-6 inducing ATM phosphorylation increases the expression of MMP-3/MMP-13, augments the abilities of cell migration, and promotes lung cancer metastasis, indicating that ATM is a potential target molecule to overcome IL-6 correlated lung cancer metastasis.     

Resident stromal cell-derived MMP-9 promotes the growth of colorectal metastases in the liver microenvironment

Colorectal cancer, the second leading cause of cancer deaths in the United States, has a high probability of metastasizing to the liver. Matrix metalloproteinases (MMPs) are a family of zinc dependent endopeptidases that are implicated in cancer metastasis and many aspects of tumor progression. Using a splenic injection experimental metastasis model, mice that are genetically deficient in MMP-9 demonstrated a nearly 2-fold decrease in liver weight compared with wild type (WT) mice following injection with MC38 syngeneic colorectal cancer cells. Bioluminesence imaging data demonstrates an early negative effect on tumor growth in MMP-9 null mice when compared with WT controls. Reconstitution of the bone marrow in MMP-9-/- mice with cells competent to produce MMP-9 did not recapitulate the WT phenotype of overwhelming burden of metastatic disease in the liver. In situ hybridization revealed the presence of MMP-9 mRNA in both MC38 tumor cells and in surrounding stromal cells, and immunostaining with anti MMP-9 was consistent with MMP-9 expression by resident liver Kupffer cells. Stromal-derived MMP-9 contributes to the establishment and growth of colorectal metastases in the liver. Stromal MMP-9 was derived from resident cells, most likely Kupffer cells, as opposed to infiltrating bone marrow-derived cells and the effect of stromal MMP-9 was independent of expression of MMP-9 by tumor cells. Stromal-derived MMP-9 may represent an important target for selective inhibition in the treatment of metastases. (c) 2007 Wiley-Liss, Inc.     

肺癌干细胞与肺癌转移相关机制的研究进展

肺癌干细胞是来源于肺癌具有自我更新及多向分化潜能的一部分细胞群,被认为是肺癌发生发展的根源,其在肺癌转移过程中扮演重要角色,可能的作用机制主要包括上皮间质转化、肿瘤微环境、肿瘤血管生成、肿瘤耐药性、信号转导通路等几个方面.本文将对肺癌干细胞与肺癌转移相关机制做进一步探索,以期为防治肺癌转移提供新策略.     

MT1-MMP和TIMP-2在非小细胞肺癌中的表达及与病理特征的相关性

目的 研究NSCLC中MT1-MMP及TIMP-2的表达及与病理类型分型、淋巴结转移和TNM分期关系.方法 采用免疫组化SP法检测MT1-MMP及TIMP-2在80例NSCLC患者和80例癌旁组织中的表达.结果 在NSCLC中MT1-MMP阳性表达率为73.8%,癌旁组织中为52.5%,(P<0.05).在NSCLC中TIMP-2的阳性表达率为42.5%,癌旁组织为72.5%,(P<0.05).MT1-MMP和TIMP-2的表达与肺癌的病理分类及肿瘤大小无关,而与TNM分期及淋巴结转移有关.MT1-MMP和TIMP-2的表达呈负相关(r=-0.635,P<0.05).结论 MT1-MMP和TIMP-2可能参与了NSCLC的发生发展过程,有望成为判断肺癌转移和预后的指标.     

MT1-MMP和TIMP-2在非小细胞肺癌中的表达及与病理特征的相关性

目的：研究NSCLC中MT1-MMP及TIMP-2的表达及与病理类型分型、淋巴结转移和TNM分期关系。方法：采用免疫组化SP法检测MT1-MMP及TIMP-2在80例NSCLC患者和80例癌旁组织中的表达。结果：在NSCLC中MT1-MMP阳性表达率为73.8%,癌旁组织中为52.5%,（P〈0.05）。在NSCLC中TIMP-2的阳性表达率为42.5%,癌旁组织为72.5%,（P〈0.05）。MT1-MMP和TIMP-2的表达与肺癌的病理分类及肿瘤大小无关,而与TNM分期及淋巴结转移有关。MT1-MMP和TIMP-2的表达呈负相关（r=-0.635,P〈0.05）。结论：MT1-MMP和TIMP-2可能参与了NSCLC的发生发展过程,有望成为判断肺癌转移和预后的指标。     

肺癌所致血小板增多及临床意义

目的探讨肺癌所致血小板增多及其与肺癌转移的关系。方法检测肺癌患者早中期和晚期两组的血小板数,并与正常人比较。结果肺癌早中期和晚期患者的血小板计数分别为(242.07±53.79)×109/L和(277.50±68.04)×109/L,均比正常人血小板计数(214.08±40.86)×109/L高,且晚期患者的血小板计数高于早中期患者。结论血小板与肺癌的发生、发展和转移有关,血小板增多可作为一个预后判断因素,抗血小板治疗是肺癌综合治疗所必须的。     

Intratumoral macrophage counts correlate with tumor progression in colorectal cancer

Background

The role of intratumoral tumor‐associated macrophages (TAMs) in colorectal cancer (CRC) is not clear. We aim to examine the relationships of TAMs and the clinicopathologic features of CRC and the expression of matrix metalloproteinases (MMP)‐2 and MMP‐9.

Methods

Immunohistochemical staining of CD68, MMP‐2, and MMP‐9 was determined in tissue samples from CRC patients. To test the biological effect of macrophages on tumor cells, cancer cells were cocultured with macrophages and function change of cancer cells were examined.

Results

Intratumoral TAM count correlated with depth of invasion (P = 0.048), lymph node metastasis (P < 0.0001), and staging (P < 0.0001) of CRC. MMP‐2 and MMP‐9 expression was significantly associated with lymph node metastasis and staging. A significant association between intratumoral TAM counts and MMP‐2 (P < 0.0001) and MMP‐9 (P < 0.0001) expression was noted. When cocultured with macrophages, cancer cells increased their invasiveness and migration and elevated MMP‐2 and MMP‐9 secretion.

Conclusions

Intratumoral TAMs cause cancer cells to have a more aggressive behavior, and this may be due to an upregulation of tumor cell‐derived MMP‐2 and MMP‐9. Examination of intratumoral TAMs can serve as a progressive marker for CRC patients. J. Surg. Oncol. 2010;102:242–248. © 2010 Wiley‐Liss, Inc.     

低剂量辐射对Lewis肺癌小鼠肿瘤微环境的影响

目的 探讨低剂量辐射(LDR)对Lewis肺癌小鼠肿瘤微环境(TME)的影响,以及高剂量辐射(HDR)前LDR预处理在TME中发挥的效应机制.方法 接种Lewis肺癌细胞(1×106)于雄性C57BL/6小鼠左侧腋下,待小鼠肿瘤直径1 cm左右(12 d),随机分为假手术Sham(1)组、LDR(2)组、HDR(3)组...     

Proteolysis in human breast and colorectal cancer.

Proteolysis occurs when proteinase activity exceeds inhibitor activity. Proteolysis is normally tightly regulated and is involved in cancer invasion and metastasis. The aim of this study was to compare proteolysis in breast and colorectal cancer. Proteinase and inhibitor expression were analysed in paired tumour and normal tissue samples from 43 breast and 24 colorectal cancer patients using substrate zymography, Western blotting and quenched fluorescence substrate hydrolysis. The expression of the latent forms of matrix metalloproteinase-2 (MMP-2), MMP-3 and MMP-9, urokinase plasminogen activator (uPA), tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2 expression were observed in both tumour and normal tissue samples from breast and colorectal tissue; however, expression was greater in the tumour tissue. Expression of active MMP-2 and MMP-9 and the total MMP activity were greater in tumour compared to normal samples in both tissues (P < 0.05). The expression of all proteinases and total MMP activity was greater in colorectal tissue than breast tissue samples. Breast and colorectal cancer demonstrated different proteinase profiles, however proteolysis in both tissues was greater in tumour tissue than normal tissue.     

Exosomes: Mediators in microenvironment of colorectal cancer

Tumor microenvironment, the soil where tumor thrives, plays a critical role in the development and progression of colorectal cancer (CRC). Various cell signaling molecules in the environment promote tumor angiogenesis, immune tolerance and facilitate immune escape. Exosomes, as messengers between tumor and host cells, are considered key mediators involved in the tumor-accelerating environment. However, the exosome-mediated communication networks in the CRC microenvironment are still largely unclear. In this review, we summarized the relationship between TME and CRC based on recent literature. Then, we revealed the unique impacts and signal molecules of exosomes on account of their regulatory role in the flora, hypoxia, inflammatory and immunological microenvironment of CRC. Finally, we summarized the therapeutically effective of exosomes in CRC microenvironment and discussed their current status and prospects, aiming to provide new molecular targets and a theoretical basis for the CRC treatment.     

Calsequestrin 2 overexpression in breast cancer increases tumorigenesis and metastasis by modulating the tumor microenvironment

The spatial tumor shape is determined by the complex interactions between tumor cells and their microenvironment. Here, we investigated the role of a newly identified breast cancer‐related gene, calsequestrin 2 (CASQ2), in tumor–microenvironment interactions during tumor growth and metastasis. We analyzed gene expression and three‐dimensional tumor shape data from the breast cancer dataset of The Cancer Genome Atlas (TCGA) and identified CASQ2 as a potential regulator of tumor–microenvironment interaction. In TCGA breast cancer cases containing information of three‐dimensional tumor shapes, CASQ2 mRNA showed the highest correlation with the spatial tumor shapes. Furthermore, we investigated the expression pattern of CASQ2 in human breast cancer tissues. CASQ2 was not detected in breast cancer cell lines in vitro but was induced in the xenograft tumors and human breast cancer tissues. To evaluate the role of CASQ2, we established CASQ2‐overexpressing breast cancer cell lines for in vitro and in vivo experiments. CASQ2 overexpression in breast cancer cells resulted in a more aggressive phenotype and altered epithelial–mesenchymal transition (EMT) markers in vitro. CASQ2 overexpression induced cancer‐associated fibroblast characteristics along with increased hypoxia‐inducible factor 1α (HIF1α) expression in stromal fibroblasts. CASQ2 overexpression accelerated tumorigenesis, induced collagen structure remodeling, and increased distant metastasis in vivo. CASQ2 conferred more metaplastic features to triple‐negative breast cancer cells. Our data suggest that CASQ2 is a key regulator of breast cancer tumorigenesis and metastasis by modulating diverse aspects of tumor–microenvironment interactions.     

Lung cancer stem cells: Tumor biology and clinical implications

The concept of cancer stem cells (CSC) has drawn great attention from researchers in both molecular and clinical fields as has brought a new perspective to the way we manage cancer. CSC have several characteristics that are shared by the properties of normal stem cells, such as differentiation, self-renewal and homeostatic control. However, CSC have the capacity to both divide and expand the CSC pool and to differentiate into heterogeneous non-tumorigenic cancer cells. Even more, CSC have an inherent high resistance to chemotherapeutic agents that leads to recurrence and poor long-term survival, especially in lung cancer patients. CSC-targeting agents are now undergoing in vitro and in vivo studies, some of which have provided promising results for further clinical studies setting. In this article we review the concept of CSC from the perspective of tumor biology, including the origin of CSC and its biomarkers. As lung cancer is the leading cause of cancer-related deaths worldwide, we focus on the properties and clinical implications of lung CSC.     

In vivo echographic evidence of tumoral vascularization and microenvironment interactions in metastatic orthotopic human neuroblastoma xenografts

Human neuroblastoma (NB) is the second most frequent solid tumor of childhood and represents a highly heterogeneous disease at clinical and biologic levels. Little progress has been made to improve the poor prognosis of patients with high-stage NB. Tumor progression and metastatic dissemination still represent major obstacles to the successful treatment of advanced stage disease. In order to develop and evaluate new, targeted, therapeutic strategies, fully defined and biologically relevant in vivo models of NB are strongly needed. We have developed an orthotopic model of metastatic human NB in the nude mouse, using 2 well-characterized NB cell lines. Tumor growth, vascular properties and metastatic patterns were investigated using a sensitive and newly developed in vivo echographic technology in addition to immunohistochemistry and PCR analyses. Results show that implantation of low numbers of NB cells directly into the adrenal gland of nude mice resulted in rapid and homogeneous tumor growth without tumor morbidity. Nude mice were shown to rapidly develop highly vascularized adrenal tumors that selectively metastasized to the liver and bone marrow. In addition, the newly formed mouse vessels in orthotopic but not in heterotopic tumors, were found to express the highly angiogenic alphavbeta3 integrin marker, indicating the development of a truly malignant neovasculature in orthotopic conditions only. This observation confirms the impact of the regional microenvironment on tumor biology and suggests the existence of cross-talk with the tumor cells. In conclusion, such model faithfully reproduces the growth, vascular and metastatic patterns as observed in patients. It therefore represents a powerful and biologically relevant tool to improve our understanding of the biology of NB and to develop and assess new antiangiogenic and metastasis-targeted therapies.     

Lung cancer with synchronous solitary brain metastasis: palliative or radical treatment?

Carcinoma of the lung is the malignancy that most commonly metastasizes to the brain. It is not uncommon for patients to have brain metastasis at the time of initial presentation with non-small cell lung cancer (NSCLC). The optimum treatment for the patients presenting with NSCLC and synchronous solitary brain metastasis has been controversial but with clear evidence of benefit in selected patients when in receipt of radical treatment for both, the lung tumor and the cerebral metastasis. Nevertheless, this treatment is not always offered to patients who are potential candidates, despite the evidence in the literature. We undertook a review of literature to assess the benefit of aggressive therapy, and which patients would benefit from it, and what constitutes the most appropriate treatment. We conclude that, in selected patients, the potentially-curative dual resection of the primary tumour and the brain metastasis can achieve improvements in survival rate and quality-of-life. However, identification of reliable prognostic factors to select appropriate patients is needed. To date there is no clear evidence regarding what should be the radical treatment for cerebral metastasis (surgery, radiosurgery, total cranial radiotherapy following either of these…)