柯萨奇-腺病毒受体在小细胞肺癌组织中阳性表达的意义

Objective  

We explored the expression of coxsackie and adenovirus receptor (CAR) in small cell lung cancer (SCLC) tissue.     

肿瘤细胞CAR表达水平与5型腺病毒转导效率的关系

目的: 通过体外、体内实验探讨肿瘤细胞柯萨奇腺病毒受体(coxsackie adenovirus receptor, CAR)表达水平与腺病毒转导效率的关系,为腺病毒相关的生物制剂在临床个体化应用提供实验依据.方法: 将载有绿色荧光蛋白的Ad5 型腺病毒(Ad-GFP) 以100 MOI、200 MOI分别感染人食管癌细胞系KYSE510、KYSE150、EC9706、人宫颈癌细胞系HeLa、人卵巢癌细胞系SKOV3、人肝癌细胞系HepG2和人肺癌细胞系A549,感染后48 h通过流式细胞术检测Ad-GFP对不同细胞系的转导效率.采用Western blotting方法检测这些细胞中CAR的表达水平.将HeLa、A549、SKOV3、EC9706细胞分别接种于裸鼠腋下,接种细胞数分别为3×106、3×106、3×106、2×106,建立裸鼠移植瘤模型.待肿瘤长径达5～7 mm时,在裸鼠移植瘤内注射Ad-GFP,每次1×109PFU,间隔48 h注射第2次.第2次注射后48 h处死裸鼠,剖取瘤组织,荧光显微镜观察冰冻切片中GFP的表达情况以判定腺病毒在瘤体内的转导效率,同时用免疫组化法检测瘤组织内的CAR表达水平.结果: 200 MOI Ad-GFP感染A549、HeLa、HepG2、KYSE150细胞48 h后分别有92.67%、89.31%、84.98%、74.59%的细胞表达GFP;而SKOV3、KYSE510、EC9706细胞中腺病毒的转导效率明显降低,GFP阳性率分别为30.06%、27.40%、18.93%;各种细胞的CAR蛋白表达水平与腺病毒的转导效率呈正相关.注射Ad-GFP的裸鼠移植瘤组织中可见HeLa、A549瘤组织内有明显的点状绿色荧光,而SKOV3、EC9706瘤组织内表达GFP的细胞数明显少于前两种瘤组织;HeLa、A549裸鼠移植瘤组织内大多数瘤细胞高表达CAR ( ),SKOV3、EC9706移植瘤组织内CAR表达水平较低( 或-),表明瘤体内CAR表达水平与Ad-GFP的转导效率也呈正相关.结论: 体内外实验均显示肿瘤细胞的CAR表达水平与5型腺病毒转导效率密切相关.肿瘤患者治疗前检测组织中CAR表达水平有助于规范腺病毒载体的基因治疗药物的个体化使用.     

Expression of Coxsackie and Adenovirums and its Significance in Human Lung Cancer

OBJECTIVE To study the relationship between the coxsackie and adenovirus receptor （CAR） and the development of human lung cancer. To optimize adenovirus vector-based gene therapy. METHODS The expression of CAR in 112 cases of lung cancer was examined using immunohistochemistry. At the same time, the relationship between CAR expression and clinicopathologic characteristics was analyzed, RESULTS ：lhere is a little expression of CAR in normal lung tissue. Compared with paraneoplastic epithelial tissue of the lung, the expression of CAR is generally up-regulated in tumor tissues showing a significant dif- ference （P〈0.01）. The positive rate of CAR expression in squamous cell carcinoma was 43.1%, and in adenocarcinoma 70.2%, with the difference between the two rates being statistically significant （P〈0.01）. Compared to the paraneoplastic tissues, the difference in CAR positive expression was 35.4% for squamous cell carcinoma and 38.3% for adenocarcinoma. But the difference in different stages of squamous cell carcinoma had no statistical significance （P〉0.05）. However, the expression of CAR was at a high level in the bronchioalveolar carcinomas as 80.4% were CAR positive. This research showed that there was a specially high expression of CAR in adenocarcinomas. CONCLUSION CAR is expressed in human lungs at a low level and up-regulated in the tumor tissues, suggesting that there is a relationship between adenocarcinoma and CAR. This research provides a basis for planning a regimen of gene therapy using an adenovirus vector,     

Loss of the coxsackie and adenovirus receptor contributes to gastric cancer progression

Loss of the coxsackie and adenovirus receptor (CAR) has previously been observed in gastric cancer. The role of CAR in gastric cancer pathobiology, however, is unclear. We therefore analysed CAR in 196 R₀-resected gastric adenocarcinomas and non-cancerous gastric mucosa samples using immunohistochemistry and immunofluorescence. Coxsackie and adenovirus receptor was found at the surface and foveolar epithelium of all non-neoplastic gastric mucosa samples (n=175), whereas only 56% of gastric cancer specimens showed CAR positivity (P<0.0001). Loss of CAR correlated significantly with decreased differentiation, increased infiltrative depths, presence of distant metastases, and was also associated with reduced carcinoma-specific survival. To clarify whether CAR impacts the tumorbiologic properties of gastric cancer, we subsequently determined the role of CAR in proliferation, migration, and invasion of gastric cancer cell lines by application of specific CAR siRNA or ectopic expression of a human full-length CAR cDNA. These experiments showed that RNAi-mediated CAR knock down resulted in increased proliferation, migration, and invasion of gastric cancer cell lines, whereas enforced ectopic CAR expression led to opposite effects. We conclude that the association of reduced presence of CAR in more severe disease states, together with our findings in gastric cancer cell lines, suggests that CAR functionally contributes to gastric cancer pathogenesis, showing features of a tumour suppressor.     

Impact of the coxsackie and adenovirus receptor (CAR) on glioma cell growth and invasion: requirement for the C-terminal domain

Expression of the coxsackie and adenovirus receptor (CAR) is downregulated in malignant glioma cell lines and is barely detectable in high-grade primary astrocytoma (glioblastoma multiforme). We determined the effect of forced CAR expression on the invasion and growth of the human glioma cell line U87-MG, which does not express any CAR. Although retrovirally mediated expression of full-length CAR in U87-MG cells did not affect monolayer growth in vitro, it did reduce glioma cell invasion in a 3-dimensional spheroid model. Furthermore, in xenograft experiments, intracerebral implantation of glioma cells expressing full-length CAR resulted in tumors with a significantly reduced volume compared to tumors generated by control vector-transduced U87-MG cells. In contrast, U87-MG cells expressing transmembrane CAR with a deletion of the entire cytoplasmic domain (except for the first 2 intracellular juxtamembrane cysteine amino acids) had rates of invasion and tumor growth that were similar to those of the control cells. This difference in behavior between the 2 forms of CAR was not due to improper cell surface localization of the cytoplasmically deleted CAR as determined by comparable immunostaining of unpermeabilized cells, equivalent adenoviral transduction of the cells and similar extent of fractionation into lipid-rich domains. Taken together, these results suggest that the decrease or loss of CAR expression in malignant glioma may confer a selective advantage in growth and invasion to these tumors.     

肿瘤细胞表面柯萨奇病毒 腺病毒受体与5型腺病毒感染效率的关系

目的〖HT5"SS〗: 探讨不同肿瘤细胞系柯萨奇病毒腺病毒受体（CAR）和整合素的表达水平与5型腺病毒感染效率的关系,为腺病毒基因治疗研究奠定基础。〖HT5W〗方法〖HT5"SS〗: 利用瞬时转染CAR的真核表达质粒提高肿瘤细胞表面CAR的表达,应用抗体封闭细胞表面的CAR和整合素后,通过流式细胞仪和荧光素酶分析法测定腺病毒Ad5CMVEGFP和Ad5CMVLuc对肿瘤细胞的感染效率和基因表达水平的变化。〖HT5W〗结果〖HT5"SS〗： 不同肿瘤细胞表面CAR和整合素的表达水平是不同的,其中SMMC7721和A549细胞CAR的表达量最高,而K562细胞CAR的表达水平最低;荧光显微镜和流式细胞仪检测Ad5CMVEGFP对肿瘤细胞的感染效率,结果显示5型腺病毒对于SMMC7721和A549细胞的感染效率最高,而对于K562细胞则很低;瞬时转染表达CAR的真核质粒可提高多种肿瘤细胞表面CAR的表达,较大幅度提高了5型腺病毒的感染效率。而抗体封闭肿瘤细胞表面的CAR或整合素后,腺病毒感染效率显著下降。〖HT5W〗结论〖HT5"SS〗:肿瘤细胞表面CAR和整合素的表达水平决定了腺病毒对肿瘤细胞的感染效率。     

Cell type- and region- dependent coxsackie adenovirus receptor expression in the central nervous system

Summay Model systems have shown that adenoviral vector mediated transient gene expression can potentially be applied for the treatment of brain tumours, neurodegenerative diseases and brain injuries. Most studies utilized adenovirus serotype 5 (Ad5) based vectors, which as adhesion molecules require the coxsackie adenovirus receptor (CAR) as a critical determinant for cellular infection. In this report, we have systematically characterized CAR expression in the adult human central nervous system (CNS) by using immunohistochemistry. A total of 85 specimens from various CNS regions were investigated for CAR expression in a cell type-dependent context. The most marked staining positivity was found in the choroid plexus and the pituitary gland. The neocortex had scattered positive neurons, while the white matter was mainly negative. We need to consider the possible adverse effects and the possible damage caused by adenoviral gene therapy if the virus–vector also binds to normal brain cells.     

小细胞肺癌组织中柯萨奇-腺病毒受体阳性表达的意义

目的：探讨柯萨奇 腺病毒受体（ＣＡＲ）在小细胞肺癌组织中阳性表达的意义。方法：应用免疫组化ＥｎＶｉｓｉｏｎ法检测病理诊断明确的３１例小细胞肺癌组织中ＣＡＲ的表达情况,用３例正常的肺组织做阴性对照。结果：３１例小细胞肺癌组织全部呈阳性表达,阳性率为１００％,３例非肿瘤性肺组织均呈阴性表达。结论：在小细胞肺癌组织中高表达ＣＡＲ可能提示腺病毒为载体的基因治疗将在小细胞肺癌的治疗领域起重要的作用。     

Expression of the coxsackie and adenovirus receptor in human astrocytic tumors and xenografts

The sensitivity of human tissues and tumors to infection with type C adenoviruses correlates with the expression of the human coxsackie B- and adenovirus receptor, hCAR. HCAR is heterogeneously expressed in various tissues and types of human cancer cells, which has implications for the use of adenoviruses as vectors in cancer gene therapy. Using immunoblotting, real-time PCR, FACS-analysis and sensitivity to infection with adenovirus-lacZ, we analyzed the expression level of hCAR in glioma Grade IV cell lines. With real-time PCR, we also analyzed hCAR expression in primary human astrocytomas of different malignancy grades, as well as in their xenograft derivatives. Analysis of a set of 10 cell lines showed great variation in hCAR expression. Susceptibility to Ad5lacZ correlated well with hCAR expression, whereas no correlation was observed with the expression of alphavbeta3/alphavbeta5 integrins, proposed to function as co-receptors for adenoviruses. A great variation of CAR expression was also observed in primary astrocytomas of different malignancy grades. The mean value of CAR expression was significantly lower in 22 Grade IV tumors as compared to the values for 6 Grade II (p = 0.01) and 6 Grade III (p = 0.01) tumors. When the hCAR expression in 11 xenografts derived from Grade IV gliomas were compared to the levels detected in the original parental tumors, a mean 12-fold higher expression was seen in the xenografts (P = 0.01). Two xenografts with low hCAR expression grew considerably faster than the hCAR-expressing cells. Our results have relevance for the use of adenoviruses in gene therapy against astrocytomas.     

柯萨奇病毒腺病毒受体的表达对基因工程腺病毒抗瘤活性的影响

背景与目的:腺病毒是研究最多的一种溶瘤病毒,也是基因治疗最常用的一种载体,但作为溶瘤病毒或载体,其治疗恶性肿瘤的疗效很大程度上受到组织器官表达柯萨奇病毒腺病毒受体(Coxsackieandadenovirusreceptor,CAR)的影响。本研究旨在观察CAR表达对腺病毒感染力及临床疗效的影响。方法:收集29例基因工程腺病毒(H101)临床试验患者的病理标本,用免疫组织化学法检测CAR表达,分析CAR表达与临床疗效的关系。体外通过流式细胞仪检测不同肿瘤细胞表面CAR表达,用MTT法测定病毒对不同细胞的抑制率,以观察CAR表达与H101感染力的关系。结果:29例恶性肿瘤患者中,10例有效病例CAR阳性表达者7例(70.0%),19例无效病例CAR阳性表达仅6例(31.6%),CAR表达与临床疗效呈显著性相关(P=0.048)。体外实验结果显示,不同肿瘤细胞株CAR的表达存在差异,其表达量与H101对细胞的感染力(病毒对肿瘤细胞抑制率)呈正相关(r=0.986)。结论:CAR的表达与腺病毒的感染力及临床疗效密切相关,CAR高表达的肿瘤对腺病毒治疗的疗效较低表达者明显为好。     

Expression and Significance of Coxsackie and Adenovirus Receptor in Renal-Cell Carcinoma

OBJECTIVE To investigate the expression of Coxsackie and Adenovirus receptor (CAR) in renal-cell carcinoma and the relationship of the CAR to the biological behavior of the carcinomas.METHODS The immunohistochemical SP method was used to detect the expression of Coxsaekie and Adenovirus receptor in 48 cases of renalcell carcinoma and in 12 cases of normal renal tissue 2 cm away from the tumor tissue.RESULTS The positive rates of CAR were 100% in 12 cases of para-tumcr normal renal tissue and 35.4% in 48 cases of renal-cell carcinoma respectively. The difference of CAR expression between them was significant (P＜0.05). The grades of the tumor were as follows: 22 in Grade Ⅰ, 17in Grade Ⅱ and 9 in Grade Ⅲ with the CAR positive rate being 54.5%,23.5% and 11.1%, respectively. There was a negative correlation between CAR expression and tumor grading (P＜0.05). In addition, the number of the cases in stages Ⅰ to ⅣV were 19, 13, 11 and 5 respectively, with the respective positive rates being 57.9%, 30.8%, 18.2% and 0.0%, i.e. there also was a negative relationship between CAR expression and the stage (P＜0.05).CONCLUSION CAR expression is down-regulated in renal-cell carcinoma compared with normal tissue. The level of CAR may be a sensitive predictor of differentiation, invasion and metastasis. Loss of CAR expression correlates with the invasive phenotype in our analysis of renal-cell carcinoma.     

CAR抑制卵巢癌细胞株SKOV3侵袭转移表型的研究

背景与目的:柯萨奇-腺病毒受体(coxsackieandadenovirusreceptor,CAR)最早作为2,5型腺病毒的受体而被人们发现和认识,近年的研究发现它还是粘附分子家族的一员,并参与肿瘤恶性表型改变。本研究通过转染真核表达载体,探讨其对卵巢癌细胞株SKOV3侵袭转移表型的影响。方法:利用Westernblot和RT-PCR检测4株卵巢癌细胞CAR的表达;脂质体介导转染含有全长CAR基因的真核表达质粒至SKOV3细胞,经G418筛选出稳定表达的阳性细胞克隆;体外粘附实验及软琼脂克隆形成实验验证CAR对SKOV3侵袭转移表型的影响。结果:4株卵巢癌细胞中,CAR表达水平不同程度下调,其中SKOV3细胞CAR表达缺失。转染后,SKOV3细胞CARmRNA和蛋白质水平表达均明显增高;细胞间粘附力明显增强;软琼脂克隆实验显示转染细胞每孔克隆形成数(25.3±8.9)明显低于未转染组(88.8±14.0)和转染空质粒组(82.5±19.4)。结论:外源性CAR基因的导入可以增强卵巢癌细胞SKOV3间的粘附性,从而抑制肿瘤细胞的侵袭转移表型。     

Impact of the coxsackievirus and adenovirus receptor on the adenoma-carcinoma sequence of colon cancer

Background:

Coxsackie and adenovirus receptor (CAR) has been suggested to function as a tumour suppressor. Its impact on the adenoma–carcinoma sequence of the colon, however, is unclear.

Methods:

Coxsackie and adenovirus receptor was analysed in non-cancerous and neoplastic colon samples using immunohistochemistry and quantitative RT–PCR. The function of CAR in colon cancer cell lines was determined following application of CAR siRNA or ectopic expression of a human full-length CAR cDNA.

Results:

Compared with healthy mucosa, increased CAR-mRNA expression was found in adenomas, whereas primary cancers and metastases displayed a marked decline. At the plasma membrane, CAR was present in normal mucosa samples (93%), adenomas, and metastases (100% ea.), whereas in colon cancers, it was found less frequently (49%, P<0.0001). Cytoplasmic CAR immunopositivity increased from normal mucosa (22%), to adenomas (73%, P=0.0006), primary cancers (83%, P<0.0001), and metastases (67%, P=0.0019). In cancer cell lines, CAR inhibition resulted in increased proliferation, whereas enforced ectopic CAR expression led to opposite results. Blocking the extracellular portion of CAR increased cell invasion in vitro. In mice, xenotransplants of colon cancer cells with enforced CAR expression formed significantly smaller tumours, whereas CAR inhibition increased the formation of liver metastases.

Conclusion:

We conclude that CAR facilitates complex effects during colon carcinogenesis, potentially mediated by its stage-dependent subcellular distribution; high CAR expression potentially prevents apoptosis in adenomas, loss of CAR at the plasma membrane promotes growth, and dissemination of primary cancers, and high membranous CAR presence may support the establishment of distant metastases.     

Expression of the coxsackie and adenovirus receptor in human lung cancers

The aim of this study is to elucidate the relation between expression of coxsackie and adenovirus receptor (CAR) and formation of lung cancer. We investigated the expression of CAR by immunohistochemistry, Western blot and real-time RT-PCR in 120 lung cancers. We found that CAR expression in tumor tissues was significantly higher than that in normal lung tissues. CAR expression had a correlation with the histological grade of lung squamous cell carcinoma; however, there was no relationship between the CAR expression and the other clinical pathological features. In vitro, silencing or overexpression of CAR could significantly inhibit or promote colony formation, cell adhesion, and invasion in A549 cells. Our findings demonstrated that CAR may play an essential role in the formation of lung cancer.     

A novel role for the coxsackie adenovirus receptor in mediating tumor formation by lung cancer cells

The Coxsackie Adenovirus Receptor (CAR) has primarily been studied in its role as the initial cell surface attachment receptor for Coxsackie and group C adenoviruses. Recent reports suggest that CAR mediates homotypic intercellular adhesion as part of the tight and/or adherens junction. Thus, CAR is well positioned to participate in intercellular interactions and signaling. Using an antisense (AS)-CAR plasmid vector, we silenced surface CAR expression in lung cancer cells that possessed a high basal expression of this molecule and monitored the resultant tumorigenesis. AS-CAR transfectants exhibit a profound loss in the ability to generate xenografts in scid/scid mice. The emergence of delayed-onset tumors in animals that received injection with AS-CAR transfectants correlates with the resurfacing of CAR expression, suggesting that such expression and tumor emergence are temporally related. To study the mechanism underlying the differences in tumorigenicity, control and AS-CAR cells were compared in terms of their in vitro growth potential. Whereas only subtle differences in the proliferative capacity of the two populations were evident when assayed with growth on plastic, significant differences became apparent when one compared the relative ability of these populations to form colonies in soft agar. These data indicate that silencing surface CAR expression abrogates xenograft tumorigenesis in vivo and colony formation in vitro and invoke the novel possibility that CAR expression is needed for the efficient formation of tumors by a subset of lung cancer cells.     

柯萨奇-腺病毒受体在肿瘤发生发展机制中的研究进展

柯萨奇-腺病毒受体（Coxsackie and adenovirus receptor,CAR）最早作为2型和5型腺病毒的受体而被人们发现和认识。大量研究发现CAR可以影响肿瘤细胞的生长、细胞骨架的变化、细胞间的粘附等,从而在肿瘤侵袭转移过程中起非常重要的作用。而且,CAR的表达与肿瘤的预后和腺病毒介导的减瘤效应也有密切的关系。基于CAR的重要作用,CAR已逐渐成为肿瘤发生发展机制及治疗领域研究中新的“热点”,本文结合CAR的基本结构及功能对以上研究的进展作一综述。     

Expression of Coxsackie and Adenovirurus Receptor and its Significance in Human Lung Cancer

OBJECTIVE To study the relationship between the coxsackie and adenovirus receptor (CAR) and the development of human lung cancer. To optimize adenovirus vector-based gene therapy. METHODS The expression of CAR in 112 cases of lung cancer was examined using immunohistochemistry. At the same time, the relationship between CAR expression and clinicopathologic characteristics was analyzed. RESULTS There is a little expression of CAR in normal lung tissue. Compared with paraneoplastic epithelial tissue of the lung, the expression of CAR is generally up-regulated in tumor tissues showing a significant dif- ference (P<0.01). The positive rate of CAR expression in squamous cell carcinoma was 43.1%, and in adenocarcinoma 70.2%, with the difference between the two rates being statistically significant (P<0.01). Compared to the paraneoplastic tissues, the difference in CAR positive expression was 35.4% for squamous cell carcinoma and 38.3% for adenocarcinoma. But the difference in different stages of squamous cell carcinoma had no statistical significance (P>0.05). However, the expression of CAR was at a high level in the bronchioalveolar carcinomas as 80.4% were CAR positive. This research showed that there was a specially high expression of CAR in adenocarcino- mas. CONCLUSION CAR is expressed in human lungs at a low level and up-regulated in the tumor tissues, suggesting that there is a relationship between adenocarcinoma and CAR. This research provides a basis for plan- ning a regimen of gene therapy using an adenovirus vector.     

Expression of the coxsackie adenovirus receptor in normal prostate and in primary and metastatic prostate carcinoma: potential relevance to gene therapy

Adenovirus-based gene therapy may provide an alternative mode of treatment for prostate cancer, especially for late-stage and androgen-independent disease for which there is currently no effective treatment. Efficient adenovirus infection of target cells depends upon the presence of the coxsackie adenovirus cell surface receptor, CAR, which is the primary receptor for group C adenoviruses and is important for the attachment of adenovirus to the cell membrane. To evaluate the potential efficacy of adenoviral therapy for prostate cancer, we evaluated CAR expression in normal prostate tissue and in prostate carcinoma of increasing Gleason grades in paraffin-embedded, archival tissues using a polyclonal antibody raised against human CAR. Immunohistochemical analysis of benign prostate epithelia demonstrated intense luminal and lateral cell membrane staining. There was a statistically significant difference in CAR membrane expression with respect to Gleason score. In addition, metastatic prostate specimens demonstrated strong membrane staining for CAR. Adenovirus therapy may, therefore, provide an alternate modality in the treatment of prostate cancer and may be especially efficacious in the treatment of metastatic disease.     

TGFBI expression reduces in vitro and in vivo metastatic potential of lung and breast tumor cells

Controversy has arisen as to the role of transforming growth factor-β-induced protein (TGFBI) in the regulation of tumor metastasis. Using lung and breast cancer cell lines (H522 and MCF-7, respectively), we established that TGFBI induced cell adhesion to extracellular matrix proteins by activating adhesion-associated signaling and subsequent structure reformation, ultimately leading to cells less motile; whereas TGFBI reduced abilities of colony formation in soft agar, penetration through matrix gel, and activation of matrix metalloproteinases 2 and 9. Furthermore, injection of TGFBI-expressing cells into immuno-deficient mice resulted in a significant reduction in tumor metastasis in vivo. Taken together, these data suggest that TGFBI moderates the metastatic potential of cancer cells.