Propagation of mouse mammary tumor cell lines and production of mouse mammary tumor virus in a serum-free medium

Summary Five different mouse mammary tumor cell lines were propagated in a serum free medium. Evaluation of growth characteristics, including logarithmic growth, cell population increase, protein production and days to confluency, showed serum-free medium comparable to serum-containing medium. Mouse mammary tumor virus expression and production, in C₃H and GR tumor cell lines, as determined by virus particle counting and RNA dependent DNA polymerase assays, subsequent to dexamethasone stimulation revealed equivalent to higher levels of virus in serum-free medium as compared to serum-containing medium.     

Polyploid mitosis and depolyploidization promote chromosomal instability and tumor progression in a Notch-induced tumor model

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microRNAs在肿瘤免疫中的调控作用

microRNAs（miRNAs）是一类转录后调控基因表达的内源性非编码微小RNA。愈来愈多的研究显示,miRNAs在肿瘤免疫应答中发挥重要调控作用。一方面,miRNAs通过转录后调控ICAM（intercellular adhesion molecule）、B7（CD80／86）和HLA—G（human leucocyte antigen—G）等肿瘤表面分子的表达,影响肿瘤的免疫原性;另一方面,miRNAs通过平衡肿瘤局部的细胞因子微环境或调控肿瘤免疫相关细胞的分化、发育及功能发挥,调节机体抗肿瘤免疫应答。为后续深入研究肿瘤与宿主的相互作用机制,以及发展更有效的肿瘤生物治疗手段,就目前miRNAs在肿瘤免疫中的调控作用的研究进展做一综述。     

Inhibition of attachment and growth of tumor cells on collagen by a monoclonal antibody

Summary A murine monoclonal antibody, VM-1, which binds to basal cells of normal human epidermis, reduces the ability of human squamous cell carcinoma cells (SCL-1) derived from the skin to attach and spread on collagen by about 50% and causes cell rounding. Similar effects have been previously shown using normal human keratinocytes. The attachment of cell lines derived from human lung squamous cell carcinomas (SW1271 and SW900), melanoma A375, glioblastoma 126, and fibrosarcoma HT1080 is also inhibited by this antibody. VM-1 antibody does not bind to normal human fibroblasts, benign nevus cells, or the human B-cell-derived line 8866. VM-1 antibody inhibits the growth of SCL-1 cells in vitro as measured by cell numbers and [³H]thymidine ([³H]TdR) incorporation. It is not cytolytic in the presence of complement as measured by⁵¹Cr release. Repeated treatment of SCL-1 cells with VM-1 antibody significantly reduces the proportion of SCL-1 cells that attach to collagen. In addition, after treatment of SCL-1 cells with VM-1 antibody, several proteins can no longer be demonstrated by gel electrophoresis of the cell-free supernatant. The VM-1 antibody effect on attachment and spreading is partially reversed by pretreatment of the collagen surface with laminin and fibronectin, but not with the carbohydrates chondroitin-6-sulfate or hyaluronic acid or with the protein lysozyme. By fluorescence staining, the antigen recognized by VM-1 antibody is membrane-bound and Triton X-100 extractable. The VM-1 antigen is excluded from Bio-Sil TSK-400 and sediments at about 10.5 S. It has a covalent molecular weight on the order of 10⁶. Proteinase K digestion produces VM-1 antibody reactive fragments, assumed to be polysaccharides, with a polydisperse molecular weight distribution in the range 5000 to 30 000. The VM-1 antigen is partially lost from solution on boiling and is no longer detectable in the aqueous or organic phase after chloroform-methanol extraction. The properties of the VM-1 antigen are consistent with those of a proteoglycan involved in attachment and spreading of kerationcytes and certain tumor cells on collagen. This research was supported by a grant from the Elsa U. Pardee Foundation, a Training Grant from the National Institutes of Health, Bethesda, MD, and the Psoriasis Research Institute. Part of this work has appeared as an abstract in Fed. Proc. 43:1929, Abst. #2994, 1984.     

Hyaluronan promotes tumor lymphangiogenesis and intralymphantic tumor growth in xenografts

Hyaluronan （HA）, a high molecular weight glycosaminoglycan in the extracellular matrix, has been implicated in the promotion of malignant phenotypes, including tumor angiogenesis. However, little is known about the effect of HA on tumor-associated lymphangiogenesis. In this study, mouse hepatocellular carcinoma Hca-F cells combined with or without HA were injected subcutaneously into C3H/Hej mice, then angiogenesis and lymphangiogenesis of implanted tumors were examined by immunostaining for plateletendothelial cell adhesion molecule-1 and lymphatic vascular endothelial hyaluronan receptor-1 respectively. Interestingly, we found HA promotes tumor lymphangiogenesis and the occurrence of intratumoral lymphatic vessels, but has little effect on tumor angiogenesis. Moreover, HA also promotes intralymphatic tumor growth, although it is not sufficient to potentiate lymphatic metastasis. These results suggest that HA, which is elevated in most malignant tumor stroma, may also play a role in tumor progression by promoting lymphangiogenesis.     

基于碳酸酐酶IX的肿瘤成像和治疗研究进展

碳酸酐酶IX (carbonic anhydrase IX, CAIX)是一种在乏氧肿瘤细胞表面特异性过表达的跨膜蛋白,具有调节肿瘤细胞内外酸碱度的功能,与肿瘤增殖、侵袭和转移息息相关。因此,CAIX是一个很有潜力的肿瘤成像和治疗靶点。本文详细阐述了基于CAIX的肿瘤成像、治疗和诊疗一体化的研究进展,并对CAIX作为抗肿瘤靶点的应用前景进行了展望。     

Concomitant sertoli and leydig cell tumor of the testis: a case report

A rare intratubular gonadal stromal tumor was present in the testis of a 45-year-old man who was admitted to our hospital with the chief complaint of gradual enlargement of the left testis. Tumoral markers were negative and no extension was observed. The tumor comprised an intratubular mixture of two types of tumor cells with intercellular junctions: the predominant tumor cells were consistent with a Sertoli cell origin and cells comprising the minor population consistent with a Leydig cell origin. The patient is disease free after 6-month follow-up. The case is considered to be a testicular mixed tubular Sertoli-Leydig cell tumor. It highlights a rare type of primary tumor of the testis that features a good prognosis.     

Sertoli-Leydig cell tumor - a rare androgen secreting ovarian tumor in postmenopausal women. Case report and review of literature

Sertoli-Leydig cell tumors (SLCT) constitute only 1-0.5% of all primary ovarian neoplasms. We report a SLCT in a postmenopausal woman aged 69 years. The physical examination revealed severe hirsutism. Basal hormonal evaluation showed high plasma testosterone and estradiol values, with suppressed plasma gonadotropins. Computer tomograph scan revealed a right ovarian tumor mass of 4,3/3 cm, confirming an androgen secreting ovarian tumor. The histopathological and immunocytochemical examination established the diagnosis of well differentiated Sertoli-Leydig cell tumor. The tumor was positive for cytokeratin KL 1 and S-100 protein and, in isolated tumor cells, positive for alpha-fetoprotein. Postsurgical evolution was favorable; controls after 6 months and 3,5 years showed marked reduction of hirsutism, normal plasma testosterone values and gonadotropins in normal postmenopausal range. We discuss the complex aspects of etiology and pathogenesis, the clinical and hormonal settings, the role of immunocytochemical markers in diagnosis, as well as the therapy and the prognostic features of this ovarian tumor.     

The actin cytoskeleton-associated protein zyxin acts as a tumor suppressor in Ewing tumor cells

Changes in cell architecture, essentially linked to profound cytoskeleton rearrangements, are common features accompanying cell transformation. Supporting the involvement of the microfilament network in tumor cell behavior, several actin-binding proteins, including zyxin, a potential regulator of actin polymerization, may play a role in oncogenesis. In this work, we investigate the status of zyxin in Ewing tumors, a family of pediatric malignancies of bone and soft tissues, which are mainly associated with a t(11;22) chromosomal translocation encoding the EWS-FLI1 oncoprotein. We observe that EWS-FLI1-transformed murine fibroblasts, as well as human Ewing tumor-derived SK-N-MC cells, exhibit a complete disruption of their actin cytoskeleton, retaining very few stress fibers, focal adhesions and cell-to-cell contacts. We show that within these cells, zyxin is expressed at very low levels and remains diffusely distributed throughout the cytoplasm, instead of concentrating in actin-rich dynamic structures. We demonstrate that zyxin gene transfer into EWS-FLI1-transformed fibroblasts elicits reconstitution of zyxin-rich focal adhesions and intercellular junctions, dramatic reorganization of the actin cytoskeleton, decreased cell motility, inhibition of anchorage-independent growth and impairment of tumor formation in athymic mice. We observe similar phenotypic changes after zyxin gene transfer in SK-N-MC cells, suggesting that zyxin has tumor suppressor activity in Ewing tumor cells.     

Autowaves in a model of invasive tumor growth

A mathematical model for invasive tumor growth is proposed, which takes into account cell division, death, and motility. The model includes local cell density and the distribution of nutrient (oxygen) concentration. Cancer cells die in the absence of nutrients; therefore, the distribution of oxygen in tissue substantially affects both the tumor proliferation rate and its structure. The model adequately describes the experimentally measured rate of tumor proliferation. The existence of autowave solutions is demonstrated, and their properties are investigated. The results are compared with the properties of the Kolmogorov-Petrovskii-Piskunov and Fisher equations. It is shown that the nutrient distribution influences the selection of speed and the convergence of the initial conditions to the automodel solution.     

Discovering dominant tumor immune archetypes in a pan-cancer census

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糖鞘脂介导细胞凋亡及其在肿瘤治疗中的研究进展

糖鞘脂（glycosphingolipids,GSLs）广泛存在于各种生物细胞膜的磷脂双分子层中,在维持细胞膜稳定性、调节包括粘附、增殖、凋亡和识别等多种细胞过程方面发挥着重要作用,并参与细胞多种生命活动。除此之外,GSLs与细胞凋亡过程密切相关,肿瘤相关GSLs有望作为恶性肿瘤的诊断标志物和免疫治疗靶点,这些发现对研究细胞凋亡及肿瘤治疗的新方向具有重要意义。因此,本文综述了GSLs介导细胞凋亡及其影响肿瘤细胞发生、发展和转移的最新研究进展,并讨论了GSLs代谢途径及其在肿瘤治疗中的研究现状,以及基于GSLs的靶向治疗策略的发展前景。     

CRISPR-Cas13a系统用于肿瘤诊断与治疗的进展

CRISPR-Cas系统是一种目前已知的基因编辑工具,其中以靶向DNA基因组编辑的CRISPR-Cas9系统的研究较为成熟。相较于靶向DNA的基因组编辑技术CRISPR-Cas9系统,近年来靶向RNA的Ⅵ型-CRISPR家族CRISPR-C2c2/Cas13a系统研究日渐增多。CRISPR-Cas13a系统具有特异性识别并结合单链RNA序列从而非特异性切割RNA的特点,可应用于检测肿瘤外周血游离核酸,对早期肿瘤患者进行筛查。同时,Cas13a在进行体内RNA切割的过程中,不涉及编码基因DNA的改变,可直接对基因转录产物mRNA进行编辑,达到基因修饰的目的,并能够同时靶向多基因转录产物从而调控基因的表达。Cas13a系统可应用于分子诊断及RNA编辑中,该系统在肿瘤的诊断与治疗中也被证实具有广阔的发展前景。基于已有的文献资料,文中综述了靶向RNA的CRISPR-Cas13a技术应用于肿瘤诊断与治疗的研究进展,探讨了CRISPR-Cas13a系统对癌症治疗的新思路及存在的局限,并展望了未来可能的研究方向。     

The RAGE/multiligand axis: a new actor in tumor biology

The receptor for advanced glycation end-products (RAGE) is a multiligand binding and single-pass transmembrane protein which actively participates in several chronic inflammation-related diseases. RAGE, in addition to AGEs, has a wide repertoire of ligands, including several damage-associated molecular pattern molecules or alarmins such as HMGB1 and members of the S100 family proteins.Over the last years, a large and compelling body of evidence has revealed the active participation of the RAGE axis in tumor biology based on its active involvement in several crucial mechanisms involved in tumor growth, immune evasion, dissemination, as well as by sculpturing of the tumor microenvironment as a tumor-supportive niche. In the present review, we will detail the consequences of the RAGE axis activation to fuel essential mechanisms to guarantee tumor growth and spreading.     

循环肿瘤细胞识别技术研究现状

循环肿瘤细胞(CTCs)对恶性肿瘤传播转移有重要影响,因此CTCs识别技术的出现与不断进步有着重要的临床意义,准确可靠的CTCs识别技术将为尽早确诊肿瘤、指导个性化治疗方案、诊断微小残留病变以及评估抗癌药物的敏感性提供强有力的工具。本文针对核酸检测法、免疫细胞化学术、流式细胞术和基于表征特性图像识别技术等CTC识别技术的发展情况进行了综述总结,比较各种技术的优缺点,对现阶段该领域存在的问题进行了讨论,并对CTCs识别的技术发展方向作了进一步的展望,为学者们提供更广的研究思路。     

超抗原抗癌药物研究进展

肿瘤患的免疫系统通常处于免疫抑制状态,因此如何增强激活机体免疫系统是肿瘤生物治疗关注的问题。超抗原是目前所知的最强的分裂原,极微量的超抗原便能激活大量的T细胞,能对MHC-Ⅱ 肿瘤细胞产生超抗原依赖的细胞毒作用,因而超抗原的抗癌应用颇受重视。本对超抗原抗肿瘤的研究状况及存在问题作了简要回顾。     

The zebrafish/tumor xenograft angiogenesis assay as a tool for screening anti-angiogenic miRNAs

The zebrafish/tumor xenograft angiogenesis assay is used to approach tumor angiogenesis, a pivotal step in cancer progression and target for anti-tumor therapies. Here, we evaluated whether the assay could allow the identification of microRNAs having an anti-angiogenic potential. For that, we transfected DU-145 prostate cancer cells with four microRNAs (miR-125a, miR-320, miR-487b, miR-492) responsive to both anti- and pro-angiogenic stimuli applied to human umbilical vein endothelial cells. After transfection, DU-145 cells were injected close to the developing subintestinal vessels of transgenic Tg(Kdrl:eGFP)s843 zebrafish embryos that express green fluorescent protein under the control of Kdrl promoter. At 72 h post-fertilization, we observed that green fluorescent protein–positive neo-vessels infiltrated the graft of DU-145 transfected with miR-125a, miR-320, and miR-487b. Vice versa, neo-vessel formation and tumor cell infiltration were inhibited when DU-145 cells transfected with miR-492 were used. These results indicated that the zebrafish/tumor xenograft assay was adequate to identify microRNAs able to suppress the release of angiogenic growth factors by angiogenic tumor cells.

Electronic supplementary material

The online version of this article (doi:10.1007/s10616-014-9735-y) contains supplementary material, which is available to authorized users.     

miR-4510 acts as a tumor suppressor in gastrointestinal stromal tumor by targeting APOC2

Dysregulation of microRNAs (miRNAs) expression has been demonstrated in gastrointestinal stromal tumor (GIST). In this study, we aimed to determine the differential miRNAs expression in GISTs and explore the functional mechanism of differential miRNAs in GIST cells. We measured differential miRNAs in six pairs of GIST tissues and matched adjacent tissues through a high-throughput sequencing, which was confirmed in 64 pairs of GIST tissues and adjacent tissues by real-time polymerase chain reaction. We found that miR-4510 expression was significantly downregulated in GIST tissues compared to matched control tissues. Luciferase reporter assay identified apolipoprotein C-II (APOC2) as a direct target of miR-4510. Overexpression of miR-4510 inhibited the mRNA and protein expression of APOC2. In addition, overexpression of miR-4510 suppressed GIST cell proliferation, migration, and invasion. Overexpression of miR-4510 also inhibited the phosphorylation of AKT and ERK1/2, reduced the expression of matrix metallopeptidase 2 (MMP2) and MMP9. APOC2 knockdown mimicked the effect of miR-4510 overexpression. Further investigation confirmed that APOC2 was notably upregulated in GIST tissues compared to adjacent control tissues. These results suggested that miR-4510 downregulation could promote GIST progression, including growth, invasion, and metastasis, through increasing APOC2 expression.     

Immunotherapy of tumor by targeting angiogenesis

Tumor growth and metastasis are angiogenesis-dependent. Anti-angiogenic therapy represents a new strategy for the development of anti-cancer therapies. In recent years, there has been made great progress in anti-angiogenic therapy. As far as the passive immunotherapy is concerned, a recombinant humanized antibody to vascular endothelial growth factor (VEGF)-Avastin has been approved by FDA as the first angiogenesis inhibitor to treat colorectal cancer. For active specific immunotherapy, various strategies for cancer vaccines, including whole endothelial cell vaccines, dendritic cell vaccines, DNA vaccines, and peptides or protein vaccines, have been developed to break immune tolerance against important molecules associated with tumor angiogenesis and induce angiogenesis-specific immune responses. This article reviews the angiogenesis-targeted immunotherapy of tumor from the above two aspects.     

Metabolic regulation of ferroptosis in the tumor microenvironment

Ferroptosis is an iron-dependent, nonapoptotic form of regulated cell death triggered by impaired redox and antioxidant machinery and propagated by the accumulation of toxic lipid peroxides. A compendium of experimental studies suggests that ferroptosis is tumor-suppressive. Sensitivity or resistance to ferroptosis can be regulated by cell-autonomous and non-cell-autonomous metabolic mechanisms. This includes a role for ferroptosis that extends beyond the tumor cells themselves, mediated by components of the tumor microenvironment, including T cells and other immune cells. Herein, we review the intrinsic and extrinsic factors that promote the sensitivity of cancer cells to ferroptosis and conclude by describing approaches to harness the full utility of ferroptotic agents as therapeutic options for cancer therapy.