| 1. |
- Carlsson, Jörgen, et al.
(författare)
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Conjugate chemistry and cellular processing of EGF-dextran
- 1999
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Ingår i: Acta Oncologica. - 0284-186X .- 1651-226X. ; 38:3, s. 313-321
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Tidskriftsartikel (refereegranskat)abstract
- Conjugates with specific binding to the epidermal growth factor receptor, EGFR, of interest for radionuclide based imaging and therapy were prepared using mouse epidermal growth factor, mEGF, and dextran. In one type of conjugate, mEGF was coupled to dextran by reductive amination in which the free amino group on the mEGF N-terminal reacted with the aldehyde group on the reductive end of dextran. The end-end coupled conjugate could be further activated by the cyanopyridinium agent CDAP, thereby introducing tyrosines to the dextran part. In the other type of conjugate, the cyanylating procedure using CDAP was applied, first to activate dextran and then allowing for the amino terminus of mEGF to randomly attach to the dextran. In the latter case, radionuclide-labelled tyrosines or glycines could be added in the same conjugation step. All types of mEGF-dextran conjugates had EGFR-specific binding since the binding could be displaced by an excess of non-radioactive mEGF. The conjugates were to a large extent internalized in the test cells and the associated radioactivity was retained intracellularly for different times depending on both the type of cells and conjugate applied. Different intracellular 'traffic routes' for the radionuclides are discussed as well as applications for both imaging and therapy.
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| 2. |
- Carlsson, Jörgen, et al.
(författare)
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EGFR-expression in primary urinary bladder cancer and corresponding metastases and the relation to HER2-expression. On the possibility to target these receptors with radionuclides
- 2015
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Ingår i: Radiology and Oncology. - : Walter de Gruyter GmbH. - 1318-2099 .- 1581-3207. ; 49:1, s. 50-58
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Tidskriftsartikel (refereegranskat)abstract
- Background. There is limited effect of tyrosine kinase inhibitors or "naked" antibodies binding EGFR or HER2 for therapy of metastasized urinary bladder canter and these methods are therefore not routinely used. Targeting radionuclides to the extracellular domain of the receptors is potentially a better possibility. Methods. EGFR- and HER2-expression was analyzed for primary tumors and corresponding metastases from 72 patients using immunohistochemistry and the internationally recommended HercepTest. Intracellular mutations were not analyzed since only the receptors were considered as targets and intracellular abnormalities should have minor effect on radiation dose. Results. EGFR was positive in 71% of the primary tumors and 69% of corresponding metastases. Local and distant metastases were EGFR-positive in 75% and 66% of the cases, respectively. The expression frequency of HER2 in related lesions was slightly higher (data from previous study). The EGFR-positive tumors expressed EGFR in metastases in 86% of the cases. The co-expression of EGFR and HER2 was 57% for tumors and 53% for metastases. Only 3% and 10% of the lesions were negative for both receptors in tumors and metastases, respectively. Thus, targeting these receptors with radionuclides might be applied for most patients. Conclusions. At least one of the EGFR- or HER2-receptors was present in most cases and co-expressed in more than half the cases. It is therefore interesting to deliver radionuclides for whole-body receptor-analysis, dosimetry and therapy. This can hopefully compensate for resistance to other therapies and more patients can hopefully be treated with curative instead of palliative intention.
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| 3. |
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| 4. |
- Gårdmark, Truls, et al.
(författare)
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Analysis of HER2 expression in primary urinary bladder carcinoma and corresponding metastases
- 2005
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Ingår i: BJU International. - 1464-4096 .- 1464-410X. ; 95:7, s. 982-986
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To evaluate the expression of HER2 receptors (previously reported to be over-expressed in malignant urothelium) in both primary tumours and metastases of transitional cell cancer, using two different staining methods and two different scoring techniques, considering the potential use of these receptors as targets for planned systemic anti-HER2 nuclide-based treatment. MATERIALS AND METHODS: HER2 expression was evaluated with two different immunohistochemical methods in 90 patients with primary urinary bladder cancer tumours and corresponding metastases. Sections were first stained with the commercially available breast cancer test kit (HercepTest, Dako, Glostrup, Denmark). Parallel sections were then stained with a modified HercepTest procedure. Two different evaluation criteria were compared; the HercepTest score that requires > or = 10% stained tumour cells (as for breast cancer) and a proposed 'Target score' that requires > 67% stained tumour cells. The latter score is assumed to be preferable for HER2-targeted radionuclide therapy. RESULTS: Using the HercepTest kit, the Target score gave lower fractions of positive primary tumours and metastases than the HercepTest score. The modified HercepTest staining procedure and Target score gave high HER2 values in 80% of primary tumours and 62% of metastases, which is considerably more than that obtained with the HercepTest staining and score. There was a significant decrease in HER2 positivity with increasing distance from the primary tumour. In nine sentinel-node metastases assessed, all but one were HER2-positive. Considering all regional metastases, 74% were positive, and of distant metastases, 47%; 72% of the patients with positive primary tumours also expressed HER2 in their metastases. CONCLUSIONS: When combining the modified HercepTest with customised evaluation criteria, more HER2-positive tumours were diagnosed. The degree of HER2 down-regulation was significantly higher in distant than in regional metastases. HER2-targeted therapy may be an alternative or complementary to other methods in the future treatment of metastatic urinary bladder carcinoma.
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| 5. |
- Gårdmark, Truls, 1965-
(författare)
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Urinary Bladder Carcinoma – Studies of Outcome of Current Management and Experimental Therapy
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis concerns the epidemiology, current and possible future treatment of urothelial cancer of the urinary bladder. The Swedish National Quality Registry for Bladder Cancer 1997-2001 was used to explore epidemiology, current therapies and outcome. More common in men, the incidence for Ta and T1 tumours peaks in the age range 70-79 years. There were differences in treatment activity between the reporting regions. An increasing activity was seen. Older patients received less intravesical treatment, which was also a tendency for women. The five year relative survival for all stages (Ta-T4) was 70%; 93% for Ta and 75% for T1. For Ta or T1 survival did not differ significantly between regions. Because the registry has only been running since 1997 a long term follow-up (ten years) of 250 patients comparing Bacillus Calmette-Guerin and Mitomycin-C, was performed. No differences regarding complementary treatment, progression or survival (overall or disease specific) were shown. Looking for new drugs, gemcitabine was tried for intravesical instillations. Patients were randomised to one of three dose schedules. The effect on a marker tumour lesion was evaluated after nine weeks. The overall complete response rate was 31% (9/29). Side effects were more common in women but generally mild; the most common was nausea. One patient stopped instillations (nausea and fever). No patients were excluded due to pathological changes in laboratory parameters. For metastasised disease, over-expression of the growth factor receptor HER2 on urothelial cancer cells was explored in primary tumours and metastases, aiming at radionuclide target therapy. With a new antigen retrieval procedure and evaluation protocol 80% of primary tumours overexpressed the receptor and 72% remained so in the metastases. In conclusion current therapies were increasingly used by clinicians. Superiority for BCG could not be proven. Prerequisites for new therapies have been explored and the way has been paved for future studies.
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| 6. |
- Persson, Mikael, 1975-
(författare)
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Antibody Mediated Radionuclide Targeting of HER-2 for Cancer Diagnostics and Therapy : Preclinical Studies
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Targeted radionuclide therapy (TRT) holds great promise for the treatment of cancer. In TRT, radioactive nuclides are delivered specifically to tumours by molecules that recognise and bind to structures overexpressed by, or specific to, cancer cells. Human epidermal growth factor receptor like protein 2 (HER-2) is an oncogene product overexpressed in e.g. urological, breast, or ovarian cancers that have been correlated to poor prognosis and resistance to hormonal therapy. There is also evidence that tumour cells retain their HER-2 overexpression in metastases. Trastuzumab and pertuzumab are two humanised monoclonal antibodies targeting different parts of HER-2. This thesis describes the radiolabelling of these antibodies for use in TRT and diagnostics. The thesis also investigates possible methods for modifying uptake and retention of radioactivity delivered with antibodies binding to HER-2. Modification of the cellular retention of 125I by using polyhedral boron anion based linker molecules (DABI and NBI) is investigated, and it is shown that linking 125I to trastuzumab using DABI increases cellular accumulation of radioactivity by 33%. It is also shown that trastuzumab can be efficiently coupled to the positron emitter 76Br by using NBI. Furthermore, it is shown that cellular uptake of 125I can be modified by stimulating EGFR (HER-1) with EGF. When labelled with the alpha emitter 211At, trastuzumab could specifically kill cells in vitro. This cell killing effect could be prevented by saturating the receptors of the target cells with non-radiolabelled trastuzumab. Pertuzumab was radiolabelled with the low energy beta emitter 177Lu without losing affinity or immunocompetence. [177Lu]pertuzumab was specific to HER-2 in vitro and in vivo. This targeting conjugate was shown to increase median time to tumour progression in mice bearing xenografts of the radioresistant SKOV-3 cell line. In conclusion, antibodies against HER-2, especially pertuzumab radiolabelled with 177Lu, show promise as TRT agents.
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| 7. |
- Persson, Mikael, et al.
(författare)
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[Lu-177]pertuzumab : Experimental therapy of HER-2-expressing xenografts
- 2007
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 67:1, s. 326-331
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Tidskriftsartikel (refereegranskat)abstract
- Pertuzumab (Omnitarg) is a novel antibody against HER-2, domain II. HER-2 is a tyrosine kinase receptor that is overexpressed in several carcinomas, especially breast cancer. Pertuzumab, labeled with the low-energy beta emitter Lu-177, might be a candidate for targeted radiotherapy of disseminated HER-2-positive micrometastases. The radiolabeled antibody [Lu-177]pertuzumab showed favorable targeting properties in BALB/c (nu/nu) mice with HER-2-overexpressing xenografts. The absorbed dose in tumors was more than five times higher than the absorbed dose in blood and more than seven times the absorbed dose in any other normal organ. Experimental therapy showed that [Lu-177]pertuzumab delayed tumor progression compared with controls (no treatment, P < 0.0001; nonlabeled pertuzumab antibody, P < 0.0001; and Lu-177-labeled irrelevant antibody, P < 0.01). No adverse side effects of the treatment could be detected. Thus, the experimental results support the planning of clinical studies applying [Lu-177]pertuzumab for therapy.
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| 8. |
- Wester, Kenneth, et al.
(författare)
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HER-2 : A possible target for therapy of metastatic urinary bladder carcinoma
- 2002
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 41:3, s. 282-288
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Tidskriftsartikel (refereegranskat)abstract
- Human epidermal growth factor receptor 2, HER-2, is overexpressed in various tumours, e.g. breast- and bladder tumours. The aim of this study was to predict the potential use of HER-2 receptors as targets in systemic treatment of disseminated bladder tumours. HER-2 expression was assessed in bladder carcinoma metastases and the corresponding primary tumours, and subsequently compared with the EGFR expression. HER-2 and EGFR expression was analysed by immunohistochemistry in formalin-fixed, paraffin-embedded tissues from 21 patients with metastatic bladder carcinoma. HER-2 was overexpressed in 81% of the primary tumours and in 67% of the metastases. All HER-2-positive metastases were from HER-2-positive primary tumours. The results for EG FR were 71% of both primary and metastases-positive tumours. In 90% of the primary tumours and 86% of the metastases, at least one of the receptors was overexpressed. These results suggest that HER-2 targeted therapy can be considered as an alternative or a complement to other modalities in the treatment of metastatic urinary bladder carcinoma.
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