CCL2 mediates cross-talk between cancer cells and stromal fibroblasts that regulates breast cancer stem cells

Cancer stem cells (CSC) play critical roles in cancer initiation, progression, and therapeutic refractoriness. Although many studies have focused on the genes and pathways involved in stemness, characterization of the factors in the tumor microenvironment that regulate CSCs is lacking. In this study, we investigated the effects of stromal fibroblasts on breast cancer stem cells. We found that compared with normal fibroblasts, primary cancer-associated fibroblasts (CAF) and fibroblasts activated by cocultured breast cancer cells produce higher levels of chemokine (C-C motif) ligand 2 (CCL2), which stimulates the stem cell-specific, sphere-forming phenotype in breast cancer cells and CSC self-renewal. Increased CCL2 expression in activated fibroblasts required STAT3 activation by diverse breast cancer-secreted cytokines, and in turn, induced NOTCH1 expression and the CSC features in breast cancer cells, constituting a cancer-stroma-cancer signaling circuit. In a xenograft model of paired fibroblasts and breast cancer tumor cells, loss of CCL2 significantly inhibited tumorigenesis and NOTCH1 expression. In addition, upregulation of both NOTCH1 and CCL2 was associated with poor differentiation in primary breast cancers, further supporting the observation that NOTCH1 is regulated by CCL2. Our findings therefore suggest that CCL2 represents a potential therapeutic target that can block the cancer-host communication that prompts CSC-mediated disease progression.     

Bone marrow-derived mesenchymal stem cells

Human mesenchymal stem cells (MSCs) contribute to the regeneration of mesenchymal tissues, and are essential in providing support for the growth and differentiation of primitive hemopoietic cells within the bone marrow microenvironment. Techniques are now available to isolate human MSCs and manipulate their expansion in vitro under defined culture conditions without change of phenotype or loss of function. Mesenchymal stem cells have generated a great deal of interest in many clinical settings, including that of regenerative medicine, immune modulation and tissue engineering. Studies have already demonstrated the feasibility of transplanted MSCs providing crucial new cellular therapy. In this review, many aspects of the MSC will be discussed, with the main focus being on clinical studies that describe the potential of MSCs to treat patients with hematological malignancies who are undergoing chemotherapy and/or radiotherapy.     

骨髓间充质干细胞体内外对胃癌细胞的趋向性

目的:探讨人骨髓间充质干细胞(human bone marrow-derived mesenchymal stem cell,hBMSC)对胃癌细胞的趋化性,为将MSC研发成为胃癌基因治疗载体提供实验依据.方法:骨髓培养法分离培养hBMSC并进行流式细胞术鉴定.Transwell实验检测hBMSC对胃癌MKN45细胞和人成纤维细胞(human fibroblast,hFB)的趋化能力.建立MKN45细胞裸鼠移植瘤模型,感染Lenti-EGFP(MOI为50)的hBMSC或hFB细胞经尾静脉注射入荷瘤小鼠,荧光显微镜下观察移植瘤组织及各脏器GFP的表达.结果:培养第3代的hBMSC细胞CD44、CD105阳性率为(96.7±1.84)％、(98.1±0.95)％,而CD34、CD45表达阴性.hBMSC细胞向MKN45细胞的趋化能力明显强于胃上皮细胞GES-1组及空白对照细胞[(239.5-54.3)vs(43.57±4.6)、(37.3±4.7)个,P＜0.01],且hBMSC向MKN45细胞的趋化能力明显强于hFB细胞向MKN45细胞的趋化能力[(239.5 ±54.3)vs(27.7 ±16.7),P＜0.01].与hFB相比,hBMSC对胃癌移植瘤组织具有明显趋向性;hBMSC组移植瘤组织内可见GFP表达,移植瘤小鼠部分肝脏(20％)及肺脏(20％)有GFP表达,但较移植瘤组织内GFP表达率和强度均低(P＜0.05).结论:hBMSC在体内外对胃癌细胞均有特异性趋化作用,有望研发为胃癌基因治疗的良好载体.     

Human bone marrow-derived mesenchymal stem cells in the treatment of gliomas

The poor survival of patients with human malignant gliomas relates partly to the inability to deliver therapeutic agents to the tumor. Because it has been suggested that circulating bone marrow-derived stem cells can be recruited into solid organs in response to tissue stresses, we hypothesized that human bone marrow-derived mesenchymal stem cells (hMSC) may have a tropism for brain tumors and thus could be used as delivery vehicles for glioma therapy. To test this, we isolated hMSCs from bone marrow of normal volunteers, fluorescently labeled the cells, and injected them into the carotid artery of mice bearing human glioma intracranial xenografts (U87, U251, and LN229). hMSCs were seen exclusively within the brain tumors regardless of whether the cells were injected into the ipsilateral or contralateral carotid artery. In contrast, intracarotid injections of fibroblasts or U87 glioma cells resulted in widespread distribution of delivered cells without tumor specificity. To assess the potential of hMSCs to track human gliomas, we injected hMSCs directly into the cerebral hemisphere opposite an established human glioma and showed that the hMSCs were capable of migrating into the xenograft in vivo. Likewise, in vitro Matrigel invasion assays showed that conditioned medium from gliomas, but not from fibroblasts or astrocytes, supported the migration of hMSCs and that platelet-derived growth factor, epidermal growth factor, or stromal cell-derived factor-1alpha, but not basic fibroblast growth factor or vascular endothelial growth factor, enhanced hMSC migration. To test the potential of hMSCs to deliver a therapeutic agent, hMSCs were engineered to release IFN-beta (hMSC-IFN-beta). In vitro coculture and Transwell experiments showed the efficacy of hMSC-IFN-beta against human gliomas. In vivo experiments showed that treatment of human U87 intracranial glioma xenografts with hMSC-IFN-beta significantly increase animal survival compared with controls (P < 0.05). We conclude that hMSCs can integrate into human gliomas after intravascular or local delivery, that this engraftment may be mediated by growth factors, and that this tropism of hMSCs for human gliomas can be exploited to therapeutic advantage.     

骨髓间充质干细胞在血液系统疾病中的研究进展

 骨髓间充质干细胞（MSC）是骨髓组织中具有多向分化潜能的一类非造血性干细胞,并可通过多种机制参与骨髓造血微环境调控及免疫功能调节,在组织工程、基因治疗、干细胞移植后移植物抗宿主病（GVHD）中应用前景广泛,是医学研究的热点。现就MSC在造血干细胞移植（HSCT）、再生障碍性贫血（CA）、多发性骨髓瘤（MM）中的研究现况及其潜在应用价值作一简要综述。     

Human bone marrow-derived mesenchymal stem cells produced TGFbeta contributes to progression and metastasis of prostate cancer

Human mesenchymal stem cells (hMSCs) play an important role in the development of human cancers. In the present study, we observed that hMSCs promoted human prostate cancer (PCa) cell PC-3 growth in vivo and in vitro. The conditional medium of hMSCs promoted the proliferation, migration, and invasion of PC-3 cells. The expression of MMP-2 and MMP-9 in PC-3 was upregulated by conditional medium of hMSCs. In addition, blocking tumor transformation factor beta (TGFβ) blunted the pro-oncogenic function of hMSCs. These results suggest that hMSCs may play a pro-oncogenic role in the growth of human prostate caner by producing TGFβ.     

脂肪来源的间充质干细胞与乳腺癌关系研究进展

脂肪来源的间充质干细胞（adipose-derived stem cells,ADSCs）对乳腺癌细胞的影响备受关注。尽管大部分基础实验研究证明ADSCs具有“促肿瘤”的作用,但是临床病例调查分析结果却有所不同。本文系统性回顾了ADSCs的生物学特性,ADSCs在乳腺癌肿瘤微环境中的作用,ADSCs对乳腺癌细胞的影响以及自体脂肪填充或移植的临床现状,对实验室基础研究及临床现状进行综述。     

Preliminary Study on Biological Properties of Adult Human Bone Marrow-derived Mesenchymal Stem Cells

目的本研究拟建立成人骨髓间充质干细胞(mesenchymal stem cell,MSCs)体外培养和扩增的方法,探讨其生物学特性,为进一步将其应用于临床奠定理论和实验基础。方法取正常成人骨髓液5 mL,用Percoll分离液(密度1．073g/mL)经密度梯度离心法分离得到单个核细胞,以2×108个细胞／cm2的密度接种于含10％新生牛血清的LG-DMEM培养液。经培养、扩增后,进行倒置相差显微镜观察其形态,MTT法测定生长曲线,流式细胞仪行细胞表面抗原及细胞周期的检测,并在透射电镜下观察其超微结构。MtT法观察MSCs的免疫调节功能,观察MSCs对K562细胞生长的影响。检测MSCs培养上清中HA、IV-C、LN浓度的动态变化。结果培养扩增获取的成人骨髓MSCs形态均一,为梭形或纺锤形的成纤维细胞样外观,生长曲线示其增殖能力强。流式细胞仪检测显示有90％以上的细胞处于G0／G1期,表面标记物中CD4表达阳性,而造血细胞表面标志CD3、CD4、CD7、CD13、CD14、CD15、CD19、CD22、CD33、CD34、CD45和与移植排斥发生密切相关的HLA-DR表达阴性。超微结构显示细胞内有丰富的细胞器。成人骨髓MSCs抑制PHA诱导的异体淋巴细胞增殖转化,其增殖转化抑制率为60．68％(P<0．01)。抑制作用同样存在于培养上清中,其增殖转化抑制率为9．00％(P<0．05)。在有PHA刺激淋巴细胞增殖的情况下,培养上清中增殖转化抑制率达20．91％(P<0．01)。和单独的K562细胞生长曲线相比,与骨髓MSCs共孵育的K562细胞生长缓慢,无明显的指数生长期。由浓度变化曲线图可以看出,随着天数的延长,HA升高较迅速,而IV-C、LN则浓度变化不大。结论所建立的分离和培养方法可获取骨髓粘附细胞中一组独特的细胞群,具有MSCs的生物学特性。初步的生物学特性研究显示其具有免疫调节、抗肿瘤、造血支持等作用,可作为组织工程中的种子细胞。     

Bone marrow-derived mesenchymal stem cells and the tumor microenvironment

Over the last decade, there has been a growing interest in the role of mesenchymal stem cells (MSC) in cancer progression. These cells have the potential to give rise to a variety of mesenchymal cells like osteoblasts, chondrocytes, adipocytes, fibroblasts, and muscle cells. In contrast to their hematopoetic counterparts, MSC are not as clearly defined, which makes the interpretation of their role in cancer progression more complex. However, the nature of the relationship between MSC and tumor cells appears dual. Primary and metastatic tumors attract MSC in their microenvironment where they become tumor-associated fibroblasts, affect tumor cell survival and angiogenesis, and have an immunomodulatory function, and vice versa in the bone marrow MSC attract tumor cells and contribute to a microenvironment that promotes osteolysis, tumor growth, survival, and drug resistance. Whether MSC are pro- or anti-tumorigenic is a subject of controversial reports that is in part explained by the complexity of their interaction with tumor cells and the large range of cytokines and growth factors they produce. The study of these interactions is a fertile ground of investigation that—as already demonstrated in the case of myeloma—should lead to novel therapeutic approaches in cancer. In this article, the biology and role of MSC in cancer is reviewed with a primary focus on bone marrow-derived MSC.     

HSV-1 amplicon viral vector-mediated gene transfer to human bone marrow-derived mesenchymal stem cells

Human bone marrow-derived mesenchymal stem cells (BM-hMSCs) are nonhematopoietic stem cells that have the potential to differentiate into adipocytes, osteocytes and chondrocytes. Because of its propensity to migrate to the sites of injury and the ability to expand them rapidly, BM-hMSCs have been exploited as potential gene transfer vehicles to deliver therapeutic genes. Herein, we evaluated the feasibility of employing herpes simplex virus type I (HSV-1) amplicon viral vector as a gene delivery vector to BM-hMSCs. High transduction efficiencies were consistently observed in different isolates of BM-hMSCs following infection with HSV-1 amplicon viral vectors. Furthermore, we demonstrated that transduction with HSV-1 amplicon viral vector did not alter the intrinsic properties of the BM-hMSCs. The morphology and cellular proliferation of the transduced BM-hMSCs were not altered. Chromosomal stability, as confirmed by karyotyping and soft agar colony assays, of the transduced BM-hMSCs was not affected. Similarly, transduction with HSV-1 amplicon viral vectors has no effect on the pluripotent differentiation potential and the tumor tropism of BM-hMSCs. Taken together, these results demonstrated that BM-hMSCs could be transduced efficiently by HSV-1 amplicon viral vector in an 'inert' manner and thus enable strategies to express potential therapeutic genes in BM-hMSCs.     

Zoledronic acid blocks the interaction between mesenchymal stem cells and breast cancer cells: implications for adjuvant therapy of breast cancer

BackgroundZoledronic acid (ZA) reduces locoregional and distant metastases in estrogen receptor (ER)-positive breast cancer patients. Since ZA rapidly concentrates in the bone following i.v. administration, we hypothesized that this phenomenon involves the mechanism of action of ZA in bone tissue.Materials and methodsMigration assays were carried out in fibronectin-coated Boyden chambers. Activation of signaling proteins was analyzed with a phosphoprotein array. Chemokines and growth factors were measured by immunoassays and real-time PCR.ResultsZA significantly reduced in bone marrow-derived mesenchymal stem cells (MSCs) the activation of AKT and mitogen-activated protein kinase and their ability to migrate. Conditioned medium (CM) from ZA-treated MSCs showed a reduced capacity to promote the migration of ER-positive MCF-7 breast cancer cells as compared with CM from untreated MSCs. The levels of the chemokine (C-C motif) ligand 5 (CCL5, also known as RANTES - Regulated upon Activation, Normal T-cell Expressed, and Secreted) and interleukin (IL)-6 were significantly reduced in MSC-CM following treatment with ZA. Anti-RANTES and anti-IL-6 antibodies almost completely abolished the migration of MCF-7 cells induced by MSC-CM. Recombinant RANTES and IL-6 significantly induced MCF-7 cell migration and their combination showed a cooperative effect. Similar results were observed in different breast cancer cell lines.ConclusionZA might exert its antitumor activity by inhibiting MSC migration and blocking MSCs’ secretion of factors involved in breast cancer progression.     

Selective interactions between epithelial tumour cells and bone marrow mesenchymal stem cells

This work is a comparative study on the features displayed by an epithelial metastatic breast cancer cell line (MCF-7) when set in co-culture with human bone marrow mesenchymal stem cells (MSC) or a feeder layer of 3T3 fibroblasts. MSC, a subset of non-haematopoietic cells in the marrow stroma, display a potential for self-renewal, proliferation and differentiation into precursors for bone, cartilage, connective and muscular tissue. Adhesion of MCF-7 cells to monolayers of MSC or 3T3 was high (95 and 85% respectively). Once attached, MCF-7 grow well on both monolayers. Morphology of MCF-7 cells, as analysed by light and epifluorescence microscopy, revealed that MCF-7 cells grow in clusters on 3T3, but disperse on MSC. Concomitant with the lost of their aggregation status, MCF-7 on MSC express low levels of the intercellular adhesion molecules, E-cadherin and epithelial-specific antigen (ESA). These results suggest that MSC represent an appropriate cell target to investigate the cellular and molecular events occurring at the interface of epithelial-marrow stromal interactions. Together, the model here described should permit to further evaluate the significance and prognostic impact of the shift of micrometastatic cells from a cluster-aggregated into a single-cell status.     

骨髓间充质干细胞在胶质瘤研究中的应用

骨髓间充质干细胞(MSC)在体内具有向肿瘤部位定向迁移能力,是比较理想的基因治疗"细胞载体".通过转染或转导的方法,在体外使MSC携带目的 基因,并获得稳定表达,然后将它们移植到宿主体内,发挥治疗作用.这种先体外后体内的过程在胶质瘤等多个系统肿瘤中进行了研究,获得阳性结果.MSC移植的安全性值得关注,其中与宿主肿瘤细胞...     

Targeted delivery of NK4 to multiple lung tumors by bone marrow-derived mesenchymal stem cells

Most advanced solid tumors metastasize to different organs. However, no gene therapy effective for multiple tumors has yet been developed. Since a unique characteristic of bone marrow-derived mesenchymal stem cells (MSCs) is that they migrate to tumor tissues, we wanted to determine whether MSCs could serve as a vehicle of gene therapy for targeting multiple tumors. First, we confirmed that mouse MSCs preferentially migrate to multiple tumors of the lung in the Colon-26 (C-26) lung metastasis model. Next, MSCs were efficiently transduced with NK4, an antagonist of hepatocyte growth factor (HGF), by an adenoviral vector with an RGD motif. MSCs expressing NK4 (NK4-MSCs) strongly inhibited development of lung metastases in the C-26 lung metastasis model after systemic administration via a tail vein. Treatment with NK4-MSCs significantly prolonged survival of the C-26-tumor-bearing mice by inhibiting tumor-associated angiogenesis and lymphangiogenesis and inducing apoptosis of the tumor cells. MSC-based gene therapy did not induce the severe adverse effects induced by conventional adenoviral vectors. These results indicate that MSCs can serve as a vehicle of gene therapy for targeting multiple lung metastatic tumors.     

Senescent mesenchymal stem/stromal cells in pre-metastatic bone marrow of untreated advanced breast cancer patients

Breast cancer is the predominant form of carcinoma among women worldwide, with 70% of advanced patients developing bone metastases, with a high mortality rate. In this sense, the bone marrow (BM) mesenchymal stem/stromal cells (MSCs) are critical for BM/bone homeostasis, and failures in their functionality, transform the BM into a pre-metastatic niche (PMN). We previously found that BM-MSCs from advanced breast cancer patients (BCPs, infiltrative ductal carcinoma, stage III-B) have an abnormal profile. This work aims to study some of the metabolic and molecular mechanisms underlying MSCs shift from a normal to an abnormal profile in this group of patients. A comparative analysis was undertaken, which included self-renewal capacity, morphology, proliferation capacity, cell cycle, reactive oxygen species (ROS) levels, and senescence-associated β‑galactosidase (SA‑β‑gal) staining of BM-derived MSCs isolated from 14 BCPs and 9 healthy volunteers (HVs). Additionally, the expression and activity of the telomerase subunit TERT, as well as telomere length, were measured. Expression levels of pluripotency, osteogenic, and osteoclastogenic genes (OCT-4, SOX-2, M-CAM, RUNX-2, BMP-2, CCL-2, M-CSF, and IL-6) were also determined. The results showed that MSCs from BCPs had reduced ,self-renewal and proliferation capacity. These cells also exhibited inhibited cell cycle progression and phenotypic changes, such as an enlarged and flattened appearance. Additionally, there was an increase in ROS and senescence levels and a decrease in the functional capacity of TERT to preserve telomere length. We also found an increase in pro-inflammatory/pro-osteoclastogenic gene expression and a decrease in pluripotency gene expression. We conclude that these changes could be responsible for the abnormal functional profile that MSCs show in this group of patients.     

Potent antitumor effects of the conditioned medium of bone marrow-derived mesenchymal stem cells via IGFBP-4

Cell transfer therapy using mesenchymal stem cells (MSCs) has pronounced therapeutic potential, but concerns remain about immune rejection, emboli formation, and promotion of tumor progression. Because the mode of action of MSCs highly relies on their paracrine effects through secretion of bioactive molecules, cell-free therapy using the conditioned medium (CM) of MSCs is an attractive option. However, the effects of MSC-CM on tumor progression have not been fully elucidated. Herein, we addressed this issue and investigated the possible underlying molecular mechanisms. The CM of MSCs derived from human bone marrow greatly inhibited the in vitro growth of several human tumor cell lines and the in vivo growth of the SCCVII murine squamous cell carcinoma cell line with reduced neovascularization. Exosomes in the MSC-CM were only partially involved in the inhibitory effects. The CM contained a variety of cytokines including insulin-like growth factor binding proteins (IGFBPs). Among them, IGFBP-4 greatly inhibited the in vitro growth of these tumors and angiogenesis, and immunodepletion of IGFBP-4 from the CM significantly reversed these effects. Of note, the CM greatly reduced the phosphorylation of AKT, ERK, IGF-1 receptor beta, and p38 MAPK in a partly IGFBP4-dependent manner, possibly through its binding to IGF-1/2 and blocking the signaling. The CM depleted of IGFBP-4 also reversed the inhibitory effects on in vivo tumor growth and neovascularization. Thus, MSC-CM has potent inhibitory effects on tumor growth and neovascularization in an IGFBP4-dependent manner, suggesting that cell-free therapy using MSC-CM could be a safer promising alternative for even cancer patients.