The localization of an anti-tumour monoclonal antibody (791T/36) in gastrointestinal tumours

Summary CD55 is a protein that protects cells from complement-mediated attack. 791Tgp72 is an antigen which has been used succesfully as a target for both tumour imaging and cancer vaccines. 791Tgp72 has recently been identified as CD55. Quantitative expression of CD55 in the tumour environment was therefore studied. Tumour cells showed a 4-100-fold increase in CD55 cell surface expression when compared to normal cells. Immunohistochemical staining of colorectal tumours also revealed high expression of CD55 in the stroma. To examine the source of this stromal CD55 the ability of both epithelial cells and endothelial cells to produce extracellular CD55 was measured. Tumour cell lines deposit CD55 into their extracellular matrix (ECM) in direct proportion to their cell surface expression. In contrast the ECM from HUVEC cells contained large amounts of CD55 despite expressing low levels of CD55 on their cell surface. Furthermore expression of CD55 on HUVEC cells was increased by exposure to VEGF. Although it remains unclear why CD55 is upregulated in the tumour environment its high level of expression on tumour cells and associated endothelium may explain why it is a good target for both imaging and immunotherapy. © 2001 Cancer Research Campaign http://www.bjcancer.com Keywords: CD55 (DAF), tumour expression; endothelium; stroma; vascular endothelial growth factor (VEGF) 80Received 27 September 1999 Revised 3 February 2000 Accepted 15 March 2000 Correspondence to : LG Durrant British Journal of Cancer (2001) 84(1), 80-86 © 2001 Cancer Research Campaign doi: 10.1054/ bjoc.2000.1570, available online at http://www.idealibrary.com on http://www.bjcancer.com and tumour-conditioned medium or VEGF (10-300 µg ml -1 : Zeneca, Alderley Park, UK) respectively for 48 h prior to harvesting the HUVECs. Tumour-conditioned media was derived from the MDA 231 breast cancer cell line. These were grown to confluence and the media replaced with serum free M199:Hams F12 medium. Following 24 h incubation the resultant conditioned media was filtered for use with the HUVEC. Fresh media was used to culture the control HUVECs. Freshly resected tumours were finely minced and dissociated in collagenase (0.05%; Boehringer Mannheim) and DNase (0.1%; Boehringer Mannheim) for 1 h at 37˚C. Monoclonal antibodiesMonoclonal antibodies 791T/36 (IgG2b anti-791Tgp72;Embleton et al, 1981), BRIC 216 (IgG1 anti-SCR 3 of CD55; Tate et al, 1989), BRIC 220 (IgG1 anti-SCR 1 of CD55; Tate et al, 1989), BRIC 110 (IgG1 anti-SCR 2 of CD55; Spring et al, 1987;Coyne et al, 1992) have been reported previously. BRIC 229 and E4.3 (Sparrow and Mckenzie, 1983) recognize CD59 and CD46 respectively. The BRIC antibodies were purchased from the Blood Group Reference laboratory (Bristol, UK). Normal mouse IgG (Sigma, Dorset, UK) and 708 monoclonal antibody (IgG2b) was used as negative control antibodies. Indirect immunofluorescenceCell lines were incubated with monoclonal antibody for 1 h at 4˚C. Cells were washed twice in fresh media containing 1% FCS and then incubat...

Section: Discussionmentioning

confidence: 99%

CD55 is over-expressed in the tumour environment

Spendlove

Morgan

et al. 2001

“…In the context of in vivo localisation of monoclonal antibodies it has already been established that radiolabelled 791T/36 antibody localises in primary or metastatic human colorectal tumours (Farrands et al, 1982;Armitage et al, 1984), but the intratumoral site of production and/or expression of the antigen was previously poorly defined. As immunohistology with 791T/36 antibody showed reactions primarily in tumour stromal elements and pseudoacini contents rather than malignant cell surfaces (Armitage et al, 1983).…”

Section: Cumentioning

confidence: 99%

“…However due to the heterogeneity of tumours (Brattain et al, 1984;Edwards, 1985;Armitage et al, 1984) it is essential to determine antigen expression on the target colorectal tumour cells. Overall tumour antigenicity has been studied on disaggregated cells from primary tumours and on cryopreserved tumour tissue sections (Finan et al, 1982;Primus & Goldenberg, 1982;Durrant et al, 1985).…”

mentioning

confidence: 99%

Antigenicity of newly established colorectal carcinoma cell lines

Durrant¹,

Robins²,

Pimm³

et al. 1986

Self Cite

Summary Cells from two adenocarcinomas, an adenoma and a metastatic node were isolated in soft agar. Expression of antigens, CEA, Y haptenic blood group and 791T-p72, defined by a range of candidate antibodies for tumour targeting was assessed.All of the cells expressed low levels of CEA but high levels of the Y haptenic blood group antigen although there was enormous inter and intraclonal variation. Of particular interest was the membrane expression of 791T-p72 antigen on all of the dividing tumour cells as previous studies had shown that 791T/36 antibody reacted with tumour stromal elements rather than malignant cell surfaces.The DNA content was abnormal in all of the cells whether they were derived from diploid or aneuploid primary tumours. They all grew readily in athymic mice and at least one monoclonal antibody, 791T/36, localised efficiently within these xenografts.Clonogenic cells therefore expressed the three tumour-associated antigens, several at higher levels than observed in the primary tumour. Monoclonal antibody 'cocktails' should therefore allow antibody mediated drug cytotoxicity to be effective at eradicating rapidly dividing tumour cells.

“…However, there were cases when immunoscintigraphy using radiolabelled antibody (IgM or IgG) detected axillary lymph node metastases not suspected by clinical examination. Thus it appears that while immunoscintigraphy may be a useful adjunct to preoperative clinical assessment and is simple and safe, a major improvement in its accuracy is needed before it can replace axillary dissection and histological examination in the accurate staging of axilla in breast cancer.The detection of overt tumour deposits by means of gammacamera imaging and radiolabelled monoclonal antibodies to tumour-associated antigens (immunoscintigraphy) has met with encouraging results (Armitage et al, 1984;Epenetos, 1985;Leyden et al, 1986;Mach et al, 1981;Rainsbury, 1984;Smedley et al, 1983;William et al, 1984). However, most of these studies have been performed on patients with well documented and widespread disease; few being prospective studies of the value of monoclonal immunoscintigraphy in the initial staging of patients with malignant disease.…”

mentioning

confidence: 99%

“…The detection of overt tumour deposits by means of gammacamera imaging and radiolabelled monoclonal antibodies to tumour-associated antigens (immunoscintigraphy) has met with encouraging results (Armitage et al, 1984;Epenetos, 1985;Leyden et al, 1986;Mach et al, 1981;Rainsbury, 1984;Smedley et al, 1983;William et al, 1984). However, most of these studies have been performed on patients with well documented and widespread disease; few being prospective studies of the value of monoclonal immunoscintigraphy in the initial staging of patients with malignant disease.…”

mentioning

confidence: 99%

The detection of axillary lymph node metastases from breast cancer by radiolabelled monoclonal antibodies: a prospective study

Tjandra

Sacks²,

Thompson³

et al. 1989

Summary In a prospective study to assess the accuracy of monoclonal immunoscintigraphy for the detection of axillary lymph node metastases in breast cancer, two murine monoclonal antibodies that react with human breast cancer (3E1.2 and RCC-1) were labelled with 13'iodine, and the radiolabelled antibody was injected subcutaneously into the interdigital spaces of both hands of 40 patients, 36 of whom had breast cancer and the remaining four of whom had fibroadenoma (the normal, contralateral axilla was used as a control). Of the patients with breast cancer, the findings from the scintigraphy images were correlated with histopathology or cytology of the axillary lymph nodes; images were regarded as positive and hence indicative of lymph node metastases if the amount of background-subtracted radioactive count in axilla on the side of breast cancer exceeded the contralateral normal side by a ratio ) 1.5:1.0 as assessed by computer analysis. Using this method, immunoscintigraphy had an overall sensitivity of 33% (23% with 1311-3E1.2 and 50% with 1311-RCC-1) for the detection of lymph node metastases and a specificity of 63% (67% with 1311-3E1.2 and 60% with 131I-RCC-1) with problems of non-specific uptake by presumably normal lymph nodes. The results of immunoscintigraphy obtained with 1311-RCC-1 (IgG) were superior to 1311-3E1.2 (IgM) although the accuracy of immunoscintigraphy using 131I-RCC-1 (56%) was not much better than preoperative clinical assessment (50%). However, there were cases when immunoscintigraphy using radiolabelled antibody (IgM or IgG) detected axillary lymph node metastases not suspected by clinical examination. Thus it appears that while immunoscintigraphy may be a useful adjunct to preoperative clinical assessment and is simple and safe, a major improvement in its accuracy is needed before it can replace axillary dissection and histological examination in the accurate staging of axilla in breast cancer.The detection of overt tumour deposits by means of gammacamera imaging and radiolabelled monoclonal antibodies to tumour-associated antigens (immunoscintigraphy) has met with encouraging results (Armitage et al., 1984;Epenetos, 1985;Leyden et al., 1986;Mach et al., 1981;Rainsbury, 1984;Smedley et al., 1983;William et al., 1984). However, most of these studies have been performed on patients with well documented and widespread disease; few being prospective studies of the value of monoclonal immunoscintigraphy in the initial staging of patients with malignant disease. Immunoscintigraphy is complicated in that imaging using intravenously administered radiolabelled antibodies has a considerable background radioactivity because of the uptake of radiolabelled material in the blood pool and extravascular spaces, and antibodies may be catabolised before reaching their target, resulting in only a very small tumour uptake. In addition, dehalogenation of radiolabelled antibody, poor penetration of the conjugate into tumour deposits and antibody binding to cross-reactive antigens present on normal cells are...