Identification of B16-F1 melanoma autocrine motility-like factor receptor

B16-F1 melanoma cells express augmented glycosylation of a Mr 78,000 (gp78) cell surface glycoprotein in response to cell shape modulation which is correlated to an increased metastatic ability in vivo and motility in vitro. A monoclonal antibody (mAb) directed against gp78 was used to study its surface distribution and possible function in cell locomotion. On motile cells, gp78 is localized by immunofluorescence to the leading lamella as well as to the trailing edge, suggesting shuffling of gp78 during cell migration. When bound to the cells the mAb induced locomotory activity similar to the effect of the cells' autocrine motility-like factor (AMLF). The enhanced motility induced by either anti-gp78 mAb or autocrine motility factor (AMF) were both inhibited by pertussis toxin, indicating that the 3F3A mAb induces cell kinesis via the same pertussis toxin-sensitive G protein pathway as has been described for other motility factors. The binding of anti-gp78 mAb to its ligand was inhibited (10-fold) by preincubation with B16-F1 AMLF containing conditioned media. Based on such functional properties, it was concluded that gp78 behaves as an AMF receptor of the B16-F1 melanoma cell.     

Induction of autocrine factor inhibiting cell motility from murine B16-BL6 melanoma cells by alpha-melanocyte stimulating hormone

We have previously reported that neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH) successfully inhibited Matrigel invasion and haptotactic migration of B16-BL6 melanoma cells towards both fibronectin and laminin without affecting their growth. In the present study, we investigated the inhibitory mechanism of tumor cell motility by alpha-MSH. Alpha-MSH significantly blocked the autocrine motility factor (AMF)-enhanced cell motility. However, alpha-MSH did neither prevent the secretion of AMF from B16-BL6 cells nor alter the expression level of AMF receptor (gp78). On the other hand, alpha-MSH induced the secretion of the motility inhibitory factor(s) from B16-BL6 cells in a concentration- and time-dependent manner. The induction of the motility inhibitor(s) was proportional to increasing levels of intracellular cAMP induced by alpha-MSH as well as forskolin, and the activity was abolished by an adenylate cyclase inhibitor, 2',5'-dideoxyadenosine (DDA). The motility-inhibiting activity in conditioned medium (CM) from alpha-MSH-treated B16-BL6 cells was found to have a m.w. below 3 kDa after fractionation. This activity was abolished by boiling but insensitive to trypsin. The treatment of tumor cells with cycloheximide reduced the activity in alpha-MSH-stimulated CM. Our results suggest that alpha-MSH inhibited the motility of B16-BL6 cells through induction of autocrine factor(s).     

Modulation of the lung colonization of B16-F1 melanoma cells by citrus pectin.

CONTEXT: Studies have shown that the galactoside-containing simple sugars and anti-galactoside-binding lectin antibodies may affect experimental tumor cell metastasis. However, the limited number of reagents used thus far necessitate further observations. PURPOSE: Natural citrus pectin (CP) and pH-modified CP (MCP), rich in galactose residues, were used to study the involvement of carbohydrates containing galactoside residues in cellular interaction in vitro and in lung colonization in vivo of B16-F1 melanoma cells. METHODS: B16-F1 melanoma cells were incubated with various concentrations of CP and MCP. Their ability to form homotypic aggregation in vitro and tumor lung colonization in vivo in 8-week-old female C57BL/6 mice was then analyzed. RESULTS: The CP binds to the surface of B16-F1 melanoma cells; this binding can be inhibited by lactose at a concentration of 0.15 M. Intravenous injection of the murine B16-F1 melanoma cells with the natural CP resulted in a significant increase (up to threefold) in the appearance of tumor colonies in the lung and in increased homotypic aggregation properties of the cells, while injection of MCP significantly decreased B16-F1 experimental metastasis (greater than 90%). CONCLUSIONS: Tumor galactoside-binding proteins mediate cellular recognition by linking oligosaccharides with terminal D-galactoside residues on adjacent cells. Successful interference with such a process with MCP may lead to a reduced ability to form tumor cell emboli and metastasis. IMPLICATIONS: These findings imply that the galactose-containing carbohydrate side chains of CP might mimic or compete with the natural ligand(s) of the tumor galactoside-binding protein (gal-lectin) and thus affect cellular interactions relevant for metastasis.     

Oxidative burst of neutrophils against melanoma B16-F10

Intensive oxidative burst was determined by chemiluminescence of peripheral blood neutrophils of mice that were intramuscularly injected with melanoma B16-F10 and/or subcutaneously with Sephadex G-200. The neutrophils from papula developed at the site of Sephadex injection were cytotoxic for the B16-F10 cells in vitro. However, survival of Sephadex injected tumour-bearing mice was lower than of control animals bearing B16-F10, while their tumours grew faster and were less necrotic. Thus, it is likely that injection of Sephadex distracted the neutrophils from the tumour allowing faster progression of the tumour, indicating that neutrophils may have an important role in the host defence against malignant cells in the early stage of tumour development.     

多胺类似物BENS对黑素瘤B16-F1细胞生长的影响

目的:探讨多胺类似物N1,N11-bis(ethyl)norspermine(BENS)对黑素瘤B16-F1细胞生长及凋亡的影响.方法:BENS处理B16-F1细胞,MTT法检测细胞存活率,FCM法检测细胞凋亡率,荧光染色法检测线粒体膜电位的变化,DNA片段化检测细胞凋亡,Western印迹法检测凋亡相关蛋白的含量.结果:多胺类似物BENS能显著抑制B16-F1细胞增殖,抑制率呈药物浓度依赖性.BENS可诱导DNA片段化,导致FCM分析中出现典型的亚凋亡峰,同时伴有细胞线粒体膜电位降低、细胞色素C由线粒体向细胞质释放和Bax由细胞质向线粒体转移等凋亡相关性改变.结论:多胺类似物BENS抑制黑素瘤B16-F1细胞生长,并能诱导该细胞凋亡,具有潜在的临床应用价值.     

Correlation between cell deformability and metastatic potential in B16-F1 melanoma cell variants

Four B16 melanoma cell variants were investigated to determine if there exists a correlation between their deformability and their metastatic potential. Cell deformability was measured as the percentage of cells traversing 10-mum diameter Nuclepore filter membranes at constant pressure as a function of time. A method was devised to circumvent common problems encountered in cell filtration experiments, i.e., cell aggregation and adhesion to the filter and failure to recover the input. F1a cells with the lowest spontaneous metastatic rate required 44 s for 50% of the cell input to traverse the filter, whereas No. 4 cells, featuring the highest metastatic rate, needed 12 s despite the fact that the cells had identical dimensions. Other variants tested showed intermediate filterability which also correlated with their metastatic potential. Cells, when pretreated with cytochalasin B at a final concentration of 21 microM exhibited increased filterability (75% and 42% greater than control for F1a and No. 4 cells, respectively). Somewhat smaller increases were observed after colchicine treatment. The findings imply major involvement of the cytoskeleton in the filterability and thus deformability of these B16 variants. Such physiochemical factors may play an important role in the metastasis of this and possibly other tumor types.     

TNF-receptor-1 adaptor protein FAN mediates TNF-induced B16 melanoma motility and invasion

Background:

Locomotion of cancer cells can be induced by TNF and other motogenic factors secreted by cells of the tumour microenvironment such as macrophages. Based on our recent findings that the TNF receptor adaptor protein FAN mediates TNF-induced actin reorganisation and regulates the directed migration of immune cells responding to chemotactic cues, we addressed the role of FAN in cancer cell motility and the formation of invadopodia, a crucial feature in tumour invasion.

Methods:

In B16 mouse melanoma cells, FAN was downregulated and the impact on FAN on cell motility and invasion was determined using in vitro assays and in vivo animal models.

Results:

Like FAN^−/− murine embryonic fibroblasts, FAN-deficient B16 melanoma cells showed defective motility responses to TNF in vitro. In vivo FAN-deficient B16 melanoma cells produced significantly less disseminated tumours after i.v. injection into mice. Danio rerio used as a second in vivo model also revealed impaired spreading of FAN-deficient B16 melanoma cells. Furthermore, FAN mediated TNF-induced paxillin phosphorylation, metalloproteinase activation and increased extracellular matrix degradation, the hallmarks of functionally active invadopodia.

Conclusion:

The results of our study suggest that FAN through promoting melanoma cellular motility and tumour invasiveness is critical for the tumour-promoting action of TNF.     

Anti-tumor effect of adenovirus-mediated gene transfer of pigment epithelium-derived factor on mouse B16-F10 melanoma

Background

Angiogenesis plays an important role in tumor growth, invasion, and eventually metastasis. Antiangiogenic strategies have been proven to be a promising approach for clinical therapy for a variety of tumors. As a potent inhibitor of tumor angiogenesis, pigment epithelium-derived factor (PEDF) has recently been studied and used as an anticancer agent in several tumor models.

Methods

A recombined adenovirus carrying PEDF gene (Ad-PEDF) was prepared, and its expression by infected cells and in treated animals was confirmed with Western blotting and ELISA, respectively. Its activity for inhibiting human umbilical vein endothelial cell (HUVEC) proliferation was tested using the MTT assay. C57BL/6 mice bearing B16-F10 melanoma were treated with i.v. administration of 5 × 10⁸ IU/mouse Ad-PEDF, or 5 × 10⁸ IU/mouse Ad-Null, or normal saline (NS), every 3 days for a total of 4 times. Tumor volume and survival time were recorded. TUNEL, CD31 and H&E stainings of tumor tissue were conducted to examine apoptosis, microvessel density and histological morphology changes. Antiangiogenesis was determined by the alginate-encapsulated tumor cell assay.

Results

The recombinant PEDF adenovirus is able to transfer the PEDF gene to infected cells and successfully produce secretory PEDF protein, which exhibits potent inhibitory effects on HUVEC proliferation. Through inhibiting angiogenesis, reducing MVD and increasing apoptosis, Ad-PEDF treatment reduced tumor volume and prolonged survival times of mouse bearing B16-F10 melanoma.

Conclusion

Our data indicate that Ad-PEDF may provide an effective approach to inhibit mouse B16-F10 melanoma growth.     

siRNA干扰鸟氨酸脱羧酶抗酶抑制因子-1的表达抑制黑素瘤细胞增殖

目的:研究siRNA干扰鸟氨酸脱羧酶抗酶抑制因子-1(ornithine decarboxylase antizyme inhibitor-1,OAZI-1)的表达对小鼠黑素瘤B16-F1细胞增殖的影响。方法:构建OAZI-1特异性siRNA表达质粒psilencer2.1-U6/OAZI-1及对照psilenc-er2.1-U6/scrambled质粒,脂质体转染法将质粒转染入B16-F1细胞,Western blotting和定量PCR检测B16-F1细胞中OAZI-1的表达。MTT法和流式细胞术检测psilencer2.1-U6/OAZI-1对B16-F1细胞增殖和细胞周期的影响;MTT法检测干扰OAZI-1表达后B16-F1细胞对抗肿瘤药物紫杉醇(docetaxel)的敏感性。结果:成功获得稳定转染psilencer2.1-U6/OAZI-1质粒的B16-F1细胞(B16/OAZI-1细胞),B16/OAZI-1细胞中OAZI-1 mRNA和蛋白表达分别为阴性对照B16/scrambled细胞的25.0%和18.9%。干扰OAZI-1的表达抑制B16-F1细胞的增殖,G0/G1期细胞比例增加[(57.0±0.8)%vs(63.5±0.7)%,P<0.01],而S期和G2/M期细胞比例减少[(31.5±0.7)%vs(27.5±0.3)%,P<0.05;(11.5±0.3)%vs(9.1±0.6)%,P<0.01]。干扰OAZI-1的表达能降低B16-F1细胞对紫杉醇的敏感性。结论:siRNA干扰OAZI-1的表达能抑制黑素瘤B16-F1细胞的增殖,并降低其对紫杉醇的敏感性。     

急性髓细胞白血病患儿骨髓自分泌运动因子受体表达及其预后意义

目的 糖蛋白AMFR(autocrine motility factor receptor)是自分泌运动因子(autocrine motility factor,AMF)的天然受体,AMFR与AMF结合后能促使细胞的运动、迁移.通过对急性髓细胞白血病(acute myelocytic leukemia,AML)患儿骨髓液单个核细胞AMFR表达情况的检测,探讨AMFR对患者预后的影响.方法 选取2011-12-01—2013-12-31郑州大学第一附属医院儿科住院的初治核型正常的AML 35例患儿作为初治组,选取同期住院排除恶性疾病的儿童30例作为对照组;采用实时定量PCR、蛋白质印记法检测初治组与对照组儿童骨髓单个核细胞中AMFR mRNA和蛋白的相对表达量,按AMFR mRNA二分住切点将初治组分为高表达组和低表达组,Kaplan-Meier法分析两组2年的总生存时间;Cox回归模型单因素和多因素分析AMFR表达水平、年龄、性别、外周血白细胞数目、骨髓原始细胞比例等因素与预后的相关性.结果 初治组按标准化疗方案进行规律化疗,根据治疗效果可分为缓解组(n=19)与复发组(n=16).初治组、缓解组、复发组与对照组AMFR mRNA的相对表达量分别为(0.61±0.11)、(0.38±0.07)、(0.86士0.12)与(0.19士0.02),各组之间两两比较,差异均有统计学意义,P＜0.001.初治组AMFR蛋白的相对表达量为(0.55±0.12),缓解组为0.28±0.07,复发组为0.72±0.13,对照组为0.14±0.06,各组之间两两比较,差异均有统计学意义,P＜0.001.采用Kaplan-Meier分析,AMFR低表达组中位生存期为710 d(95％CI为116.409～245.251),高于AMFR高表达组的69 d(95％CI为14.424～123.576),经Log-Rank统计分析,两组之间的总体生存率(OS)差异有统计学意义,P=0.003.采用Cox回归模型纠正性别、年龄、外周血白细胞数、骨髓原始细胞比例和白血病FAB分型等因素,AMFR基因mRNA表达水平和白细胞数是影响AML不良预后的因素.结论 AMFR在AML中存在高表达,其表达水平越高,临床预后越差.     

Significance of autocrine motility factor receptor gene expression as a prognostic factor in non-small-cell lung cancer.

Autocrine motility factor receptor (AMF-R) has been shown to play an important role in tumor cell migration, invasion and metastasis. We have detected AMF-R expression in tissue specimens from patients with non-small-cell lung cancer (NSCLC) and have assessed their clinical characteristics. Using RT-PCR and immunohistochemistry, we quantified the expression of AMF-R in 47 patients with NSCLC who underwent curative tumor resection, to investigate the relationship between AMF-R expression and clinicopathologic factors and prognosis. RT-PCR results agreed well with the immunohistochemic results (p < 0.0001). In 47 NSCLC patients, 34 (72.3%) samples were evaluated as having high AMF-R gene expression. AMF-R gene expression was significantly associated with lymph node metastasis and stage (p = 0.0295 for lymph node metastasis, p = 0.0152 for stage). The overall survival rate for patients with high AMF-R gene-expressing tumors was significantly worse than for those whose tumors had low AMF-R expression (p = 0.0029). Multivariate analysis also showed that AMF-R gene expression was significantly related to survival (p = 0.0165). These data indicate that AMF-R may contribute to tumor progression and that AMF-R gene expression can serve as a useful prognostic marker in NSCLC.     

Expression of autocrine motility factor receptor in human esophageal squamous cell carcinoma

Autocrine motility factor and its receptor (gp78) have been shown to play an important role in tumor cell migration, invasion and metastasis. We have detected gp78 expression in buffered-formalin-fixed, paraffin-embedded sections of esophageal squamous cell carcinomas using an anti-gp78 monoclonal antibody (MAb), 3F3A, and examined the relationship between gp78 expression and clinicopathological and prognostic factors. In 55 of 101 (54%) patients, gp78 was detected in the tumor cells. The frequency of gp78-positive expression was significantly associated with tumor size, infiltrative growth, depth of invasion and lymph node metastasis. The cumulative survival rate of patients with gp78 was significantly lower than that of patients without gp78. Our results suggest that autocrine motility factor receptor (gp78) expression could be a useful biomarker for malignancy grading and prognosis in patients with esophageal squamous cell carcinoma. © 1995 Wiley-Liss, Inc.     

Suppression of melanoma cell motility factor receptor expression by retinoic acid.

beta-All-trans-retinoic acid (RA) has been shown to inhibit the growth, enhance the differentiation, and suppress the transformed and metastatic properties of certain human and murine melanoma cells. This study examined the effect of RA on the level of a cell surface receptor (M(r) 78,000) (gp78) for an autocrine motility factor, which has been implicated in invasion and metastasis. Treatment of murine melanoma cell lines S91-C2, B16-F1, and K1735-P with RA (10 microM) for 5 days decreased the level of gp78 by 37, 72, and 92%, respectively, as revealed by immunoblotting with monoclonal antibodies raised against gp78. In contrast, RA had only a limited effect on gp78 levels in melanoma cell clones or variant cell lines that are resistant to the growth-inhibitory effects of RA (S91-C154, B16-F10, and K1735-Cl19). Further studies with K1735-P, the most sensitive cell line with respect to modulation of gp78, showed that the decrease in gp78 level required at least 1 microM RA and 4 to 5 days of treatment. The binding of anti-gp78 antibodies to the surface of intact RA-treated cells and to intracellular gp78 in permeabilized cells was also lower than in untreated cells. Furthermore, RA treatment decreased the induction of cell motility, on colloidal gold-coated glass coverslips, by anti-gp78 antibodies, which mimic the effect of autocrine motility factor. The RA-induced decrease in antibody-enhanced cell motility was similar to the time- and RA concentration-dependent decrease in the amount of gp78, suggesting that the two events are related. These results raise the possibility that the previously reported suppression by RA of tumor cell invasion and metastasis may be related, at least in part, to suppression of cell motility resulting from the decreased level of the autocrine motility factor receptor.     

Expression of autocrine motility factor receptor correlates with disease progression in human gastric cancer.

Up-regulation of autocrine motility factor receptor (AMF-R) expression has been shown to be associated with invasion and metastasis of experimental tumour systems and human neoplasms. Monoclonal antibodies against AMF-R (gp78) were used to stain 221 primary gastric cancer specimens, and level of expression was examined in relation to pathological stage and prognostic values. In 125 out of 221 (56.6%) patients, gp78 was detected. Expression of gp78 was associated with macroscopic type, lymphatic and venous invasions, and lymph node and peritoneal metastasis. The level of gp78 expression in the cancer specimens was associated with histopathological stage and grade of tumour penetration. Positive gp78 expression was significantly associated with poor prognosis (P < 0.001). This significant relationship remained among patients in stage II and III. The results suggest that gp78 expression could be used as a prognostic marker in gastric cancer patients.     

B16-F10-luc-G5黑色素瘤细胞生物学特性的研究

目的：探讨B16-F10-luc-G5黑色素瘤细胞的生物学特性.方法：倒置荧光显微镜下连续观察B16-F10-luc-G5细胞生长动态.流式细胞术检测冻存复苏后、培养基漂浮细胞、胰酶消化损伤后的细胞死亡率以评价其对实验损伤的耐受性.1×104/孔B16-F10-luc-G5细胞按1∶2梯度稀释至0.78×102/孔,加入底物荧光素后检测其生物发光特性.Babl/C和C57 bl/6雄性小鼠各10只接种该细胞,目测肿瘤生长速度和活体成像监测Babl/C小鼠移植瘤生长动态以评价其成瘤特性.结果：B16-Fl0-luc-G5细胞生长动态符合典型B16-F10细胞特性,无自发及激发荧光.B16-F10-luc-G5细胞冻存、漂浮细胞及对数生长期细胞消化后死亡率分别为23.8％、35.8％和4.8％.B16-F10-luc-G5细胞数与实测平均光子数之间存在线性回归关系,检测光子数可反映细胞数目.两组小鼠移植成瘤率均为100％,平均肿瘤出现时间差异显著（t =9.05,P＜0.05）,移植瘤病理符合B16黑色素瘤典型生长特点;活体成像监测可灵敏监测移植瘤生长动态.结论：B16-F10-luc-G5细胞具有生长快、对各种实验操作耐受性好、标记生物发光基因易追踪等优点,且其一般特性与B16-F10细胞基本相同,是肿瘤学研究良好的实验材料.     

Inhibition of experimental metastasis and extracellular matrix degradation by butanol extracts from B16-F1 murine melanoma

We previously demonstrated that noncytolytic butanol extraction of B16 melanoma cells can increase the number of experimental lung metastases, and that brief incubation of the extracted cells with the extracted moieties reduces metastatic phenotype. This study examined the possibility that the extracted components are endogenous inhibitors of tumor cell surface-associated, degradative enzymes. The activity was found to be tumor associated, since only tumor extracts could reduce the number of experimental lung metastases of a variety of solid tumors. The activity in crude butanol extracts of B16-F1 that modulated the metastatic phenotype of extracted B16-F10 was partially purified by preparative isoelectric focusing and high-performance gel permeation chromatography. Incubation of extracted B16-F10 cells with low (Mr 2,000-10,000) molecular weight materials focusing in the pH 5.6 to 5.8 region of the preparative isoelectric focusing gradient significantly reduced the number of experimental lung foci. Ampholines alone had no effect. Evidence that the extracted moiety might be an endogenous enzyme inhibitor was obtained with the use of the subendothelial matrix degradation assay, wherein B16-F10 cells digest 35S-labeled heparan sulfate proteoglycan. The same materials that reduced the metastatic potential of butanol-extracted B16-F10 cells also inhibited extracellular matrix degradation by 30 to 85%, as well as the activity of partially purified heparanase (endo-beta-glucuronidase). The metalloproteinase inhibitor 1,10-phenanthroline and the heparanase inhibitor heparin partially (30 to 50%) blocked extracellular matrix degradation. Conversely, inhibitors of serine, thiol, acid, and other proteases had little or no effect on extracellular matrix degradation. These data provide evidence that an endogenous, heat-stable inhibitor of cell surface degradative enzymes such as heparanase may play a role in hematogenous metastasis, and support the hypothesis that butanol extraction activates some of these surface enzymes by removing the endogenous inhibitors.     

鸟氨酸脱羧酶抗酶抑制因子-1高表达对小鼠黑素瘤B16-F1细胞增殖的影响

目的:研究鸟氨酸脱羧酶抗酶抑制因子-1(ornithine decarboxylase antizyme inhibitor-1,OAZI-1)高表达对小鼠黑素瘤B16-F1细胞增殖的影响。方法:采用巢氏PCR法从小鼠肝癌H22细胞cDNA中克隆出小鼠OAZI-1基因,并构建重组质粒pcDNA3.1(+)/OAZI-1。采用脂质体转染法将重组质粒转染入B16-F1细胞后,Western印迹法和实时荧光定量PCR法鉴定高表达OAZI-1的B16-F1细胞株。MTT法和FCM检测OAZI-1高表达对B16-F1细胞增殖和细胞周期的影响。反相高效液相色谱检测OAZI-1高表达对细胞内多胺水平的影响。化学发光法检测细胞内精胺氧化酶(spermine oxidase,SMO)的活性。结果:成功获得高表达OAZI-1的B16-F1细胞克隆株B16/over,该细胞中OAZI-1在mRNA水平的表达量是转染空载体质粒对照组细胞B16/3.1的3.6倍。B16/over细胞中,鸟氨酸脱羧酶抗酶(ornithine decarboxylase antizyme,OAZ)的mRNA表达水平降低,鸟氨酸脱羧酶(ornithine decarboxylase,ODC)的mRNA表达水平升高。高表达OAZI-1能促进B16-F1细胞增殖,并影响细胞周期,G0/G1期细胞减少而S期和G2/M期细胞增加。B16/over细胞中腐胺的含量明显增加,精脒和精胺的含量减少,而且SMO活性升高。结论:OAZI-1高表达可能通过增加细胞内腐胺含量,促进黑素瘤细胞增殖,提示该抑制蛋白可能成为黑素瘤治疗的一个潜在靶点。     

Effect of splenectomy upon the growth of B16-F10 melanoma and its relation to the interferon system

The influence of splenectomy upon the growth of B16-F10 malignant melanoma and changes in interferon-synthesizing ability in mice were studied. Surgical stress alone temporarily diminished the ability of mice to respond to interferon induction by poly rIrC. Two weeks following the surgery, mock-splenectomized mice fully regained their interferon synthesis ability. However, this was not true in the case of splenectomized mice. They remained refractory to interferon induction. The removal of the spleen had no obvious effect on the rate of pulmonary metastasis in mice injected with B16-F10 malignant melanoma in relation to the mock-splenectomized or control mice. Mice that were splenectomized and inoculated with B16-F10 melanoma also remained refractory to interferon induction.     

Innate immunity based cancer immunotherapy: B16-F10 murine melanoma model

Background

Using killed microorganisms or their parts to stimulate immunity for cancer treatment dates back to the end of 19^th century. Since then, it undergone considerable development. Our novel approach binds ligands to the tumor cell surface, which stimulates tumor phagocytosis. The therapeutic effect is further amplified by simultaneous application of agonists of Toll-like receptors. We searched for ligands that induce both a strong therapeutic effect and are safe for humans.

Methods

B16-F10 murine melanoma model was used. For the stimulation of phagocytosis, mannan or N-formyl-methionyl-leucyl-phenylalanine, was covalently bound to tumor cells or attached using hydrophobic anchor. The following agonists of Toll-like receptors were studied: monophosphoryl lipid A (MPLA), imiquimod (R-837), resiquimod (R-848), poly(I:C), and heat killed Listeria monocytogenes.

Results

R-848 proved to be the most suitable Toll-like receptor agonist for our novel immunotherapeutic approach. In combination with covalently bound mannan, R-848 significantly reduced tumor growth. Adding poly(I:C) and L. monocytogenes resulted in complete recovery in 83% of mice and in their protection from the re-transplantation of melanoma cells.

Conclusion

An efficient cancer treatment results from the combination of Toll-like receptor agonists and phagocytosis stimulating ligands bound to the tumor cells.

     

lncRNA CDKN2B-AS1对黑色素瘤B16-F10细胞恶性生物学行为的影响

目的：探讨长链非编码RNA CDKN2B反义RNA1（long non-coding RNA CDKN2B-antisense RNA 1, lncRNA CDKN2B-AS1）通过靶向miR-7-5p影响黑色素瘤B16-F10细胞的恶性生物学行为的影响。方法：选用黑色素瘤B16-F10细胞,构建shRNA CD‐KN2B-AS1载体并转染到B16-F10细胞,实验分为对照组、sh-CDKN2B-AS1 组、miR-7-5p mimics 组、miR-7-5p inhibitor组。用RT-PCR检测转染后B16-F10细胞中CDKN2B-AS1表达水平,用克隆形成实验和MTT法检测克隆形成数及细胞的增殖能力,用划痕愈合实验和Transwell实验检测细胞的迁移和侵袭能力。用荧光素酶报告基因实验检证CDKN2B-AS1和miR-7-5p相互间靶向关系。用RT-PCR和Western blotting检测转染miR-7-5p mimics、inhibitor后B16-F10细胞中miR-7-5p和Ki67、cleaved caspase-3、上皮钙黏蛋白（E-cadherin）、神经钙黏蛋白（N-cadherin）、Twist1蛋白的表达水平。结果：与对照组比较,sh-CDKN2B-AS1组 B16-F10细胞中CDKN2B-AS1表达水平显著下调（P<0.01）,细胞的增殖、迁移及侵袭能力显著下降（均P<0.01）。荧光素酶报告基因实验证明 CDKN2B-AS1 与 miR-7-5p 存在靶向作用关系。sh-CDKN2B-AS1 组与 miR-7-5p mimics 组细胞中 miR-7-5p 和cleaved caspase-3、E-cadherin水平均明显上调（均P<0.05）,Ki67、N-cadherin、Twist1水平明显下调（均P<0.05）。结论：CDKN2BAS1通过靶向miR-7-5p促进黑色素瘤发展,干扰CDKN2B-AS1可抑制黑色素瘤B16-F10细胞的恶性生物学行为。