astatine and Melanoma
astatine has been researched along with Melanoma* in 13 studies
Reviews
3 review(s) available for astatine and Melanoma
Article | Year |
---|---|
Targeting melanoma with 211At/131I-methylene blue: preclinical and clinical experience.
The increasing incidence of melanoma and a lack of effective therapy have stimulated a search for new methods of early detection and treatment of the disease. Melanin synthesized in melanoma cells presents a unique target to which the treatment can be selectively addressed, provided the pigment is recognized by a suitable drug. Methylene blue possesses a high affinity for melanin and, therefore, accumulates preferentially in melanoma cells. Since not directly toxic to the tumor, methylene blue serves as a carrier for radioisotopes and, once taken up by melanoma cells, acts as a selectively localized source of radiation. Hence, radioderivatives of the compound can be used for diagnosis and therapy of disseminated melanoma. 131I-methylene blue in conjunction with gamma camera imaging has already proved in clinical studies to be a useful tool for the detection of early melanoma dissemination. 211At-methylene blue exceptional efficacy in treating melanoma and preventing its metastatic spread without damaging normal structures when administered systemically to human melanoma-bearing mice led to the approval of this alpha-particle emitting methylene blue derivative for the Phase I clinical trial. Topics: Animals; Astatine; Drug Carriers; Humans; Iodine Radioisotopes; Melanoma; Methylene Blue; Mice | 1999 |
211At-methylene blue in targeted radiotherapy of disseminated melanoma.
Targeted radiotherapy with 211At-methylene blue (211At-MTB) is a systemic treatment selectively directed at melanoma due to a high affinity of MTB to melanin synthesized in the tumor cells. Since MTB forms a strong complex with melanin, it is an effective carrier for a number of radioisotopes to be addressed to the tumor deposits of any size including individually dispersed melanoma cells. Thus, appropriately radiolabeled MTB can be used for either diagnosis or therapy of the neoplasm. As predicted and found in animal experiments, 211At-MTB is most effective therapeutically. Histopathological investigations showed that the highly pigmented 211At-MTB-treated tumors were characterized initially by perivascular oedema and hydropic degeneration of tumor cells followed by gradual development of extensive areas of coagulative necrosis. The necrotic tumor areas contained microvessels occluded by thrombi and tended to undergo microfocal calcification. Although melanoma-bearing animals successfully treated with 211At-MTB did not reveal any adverse effects of the therapy, detailed toxicological studies were undertaken. No serious macro- or microscopic lesions were observed in normal organs of 211At-MTB treated mice. Only the relative number of small lymphocytes in the groin lymph nodes in a minority of animals was variably reduced, most often in conjunction with the treatment of highly, but not poorly, pigmented tumors. Topics: Animals; Astatine; Drug Carriers; Humans; Melanoma; Methylene Blue; Mice | 1994 |
Astatine-211: its possible applications in cancer therapy.
The cyclotron-produced radiohalogen, 211At, is eminently suitable as a possible therapeutic radionuclide. It decays by the emission of 6.8 MeV mean energy alpha-particles, which from a radiobiological viewpoint are of near optimal therapeutic LET. This paper reviews developments in the possible application of [211At]astato-labelled molecules as potential anti-tumour agents. Additionally, radio-dosimetric evidence is presented, and its implications for human cancer therapy are discussed. Topics: Animals; Antibodies, Monoclonal; Astatine; Humans; Melanoma; Naphthoquinones; Neoplasms; Nucleic Acid Precursors; Radiotherapy Dosage | 1986 |
Other Studies
10 other study(ies) available for astatine and Melanoma
Article | Year |
---|---|
The survival of monolayers of cells growing in clusters irradiated by 211At appended to the cell surfaces.
A model of cell survival is described for the case of closely packed clusters of cells growing in monolayers. For alpha-particle decays on the cell surfaces, it is shown that cross-firing between cells produces nonuniform dose distributions within the cluster and that cells in larger clusters are exposed on average to greater doses. The model is used to simulate the survival of SK-MEL-28 human melanoma cells labeled with different radiolabeled monoclonal antibodies. The survival data suggest that this cell line is more sensitive to high-LET radiation than previously thought. Topics: Alpha Particles; Astatine; Cell Survival; Humans; Linear Energy Transfer; Melanoma; Tumor Cells, Cultured | 1999 |
The cytotoxicity and microdosimetry of astatine-211-labeled chimeric monoclonal antibodies in human glioma and melanoma cells in vitro.
The cytotoxicity of alpha-particle-emitting endoradiotherapeutic compounds is of increasing interest because clinical evaluation of these potential therapeutic agents is commencing. Astatine-211 is a radionuclide with a 7.2-h half-life that emits 5.87 and 7.45 MeV alpha particles. In the present work, we have investigated the in vitro cytotoxicity of 211At-labeled chimeric monoclonal antibodies (mAbs) in monolayers of D-247 MG human glioma cells and SK-MEL-28 human melanoma cells. The mAbs studied were 81C6, reactive with the extracellular matrix antigen tenascin, Mel-14, directed against the cell membrane antigen proteoglycan chondroitin sulfate, and a nonspecific control mAb, TPS3.2. Cell uptake increased as a function of activity concentration after a 1-h exposure to the 211At-labeled mAbs. The retention of activity was also measured to calculate cumulative activity associated with the cells and the medium. The clonogenic survival as a function of activity concentration was linear in all cases with no detectable shoulder. Microdosimetric analyses were performed based on measured cell geometry, cumulative activity and Monte Carlo transport of alpha particles. Using 18 kBq/ml activity concentration and 1 h of incubation, a two to five times higher activity bound to the microcolonies was found for the specific mAbs compared to the nonspecific mAb. These calculations indicated that a survival fraction of 0.37 was achieved with 0.24-0.28 Gy for D-247 MG cells and 0.27-0.29 Gy for SK-MEL-28 cells. The microdosimetric cell sensitivity, z0, for D-247 MG cells was significantly lower than for SK-MEL-28 cells (0.08 compared to 0.15 Gy). For both cell lines, reduction in survival to 0.37 required an average of only 1-2 alpha-particle hits to the cell nucleus. Topics: Antibodies, Monoclonal; Astatine; Dose-Response Relationship, Immunologic; Dose-Response Relationship, Radiation; Glioma; Humans; Immunotoxins; Melanoma; Tumor Cells, Cultured | 1998 |
Cytotoxicity of alpha-particle-emitting 5-[211At]astato-2'-deoxyuridine in human cancer cells.
This study was performed to determine the cytotoxicity of alpha-particle-emitting 5-[211At]astato-2-deoxyuridine (i.e. [211At]AUdR) for monolayers of D-247 MG human glioma cells and SK-MEL-28 human melanoma cells. Cells in exponential growth were exposed to varying activity concentrations of [211At]AUdR and for comparison [211At]astatide and the Auger electron-emitting analogue, 5-[125I]iodo-2'-deoxyuridine (i.e. [125I]IUdR). Cell uptake, DNA binding and clonogenic survival as a function of activity concentration in the medium were determined following 2 and 20-h incubations. None of the survival curves had detectable shoulders, an observation consistent with high-LET effects. The A37 (initial activity concentration yielding 37% cell survival) were significantly lower for both cell lines following 20-h exposure of [211At]AUdR than [211At]astatide. After correcting for effects from non-cell-associated activity in the medium, the specific cytotoxicity of cell-associated and DNA-bound [211At]AUdR was estimated. In the 20-h incubation experiments, the A37 for DNA-associated [211At]AUdR corresponded to about one 211At atom bound per cell for both cell lines. Unlike [211At]AUdR, there was a biphasic survival response to [125I]IUdR, consistent with the lower fractional uptake of [125I]IUdR at higher activity concentrations. These studies suggest that [211At]AUdR warrants further evaluation as an endoradiotherapeutic agent for the treatment of rapidly proliferating cancers. Topics: Alpha Particles; Antineoplastic Agents; Astatine; DNA, Neoplasm; Glioma; Humans; Idoxuridine; Iodine Radioisotopes; Isotope Labeling; Melanoma; Tumor Cells, Cultured | 1997 |
[211At]methylene blue for targeted radiotherapy of human melanoma xenografts: dose fractionation in the treatment of cutaneous tumours.
3,7-(dimethylamino) phenazathionium chloride [methylene blue (MTB)] labelled with alpha-particle emitter astatine-211 (211At) selectively accumulates in melanoma cells due to an exceptionally high affinity of MTB to melanin, and proves to be a very effective agent in targeting radiotherapy for pigmented human melanoma grown in mice. This study aimed at a selection of the most advantageous [211At]MTB dose fractionation leading to irreversible regression of the treated lesions. Nude mice bearing subcutaneous human melanoma xenografts of either highly pigmented HX118 or poorly pigmented HX34 human melanoma were treated with [211At]MTB administered intravenously. The treatment was performed using three different schedules of [211At]MTB fractionation: a single large dose, five fractions delivered sequentially every 48 h and two to five fractions given with a mean frequency of one per week. The effectiveness of [211At]MTB treatment was assessed by determination of the growth rate of cutaneous tumours and length of time between tumour implantation and killing of moribund mice. [211At]MTB applied with a mean frequency of one fraction per week appeared to be the most efficient treatment for highly pigmented HX118 melanomas. Its effectiveness was dependent on [211At]MTB activity used per fraction and the size of the cutaneous tumours at the beginning of the treatment. A total dose of [211At]MTB seemed of less importance. An irreversible regression of the lesions was achieved. Poorly pigmented cutaneous melanoma xenografts were affected most significantly by [211At]MTB applied as five fractions given every 48 h. The treatment caused a temporary inhibition of tumour growth after which the lesions regained the control growth rate. These and previous results suggest that [211At]MTB could successfully control the growth of already formed lesions of pigmented melanoma, as well as prevent metastatic spread of the tumour, provided an appropriate fractionation régime of the radiolabelled compound is employed. Topics: Animals; Astatine; Drug Carriers; Female; Humans; Melanoma; Methylene Blue; Mice; Mice, Nude; Neoplasm Transplantation; Pigmentation; Skin Neoplasms; Time Factors; Transplantation, Heterologous | 1996 |
Radioiodinated methylene blue for diagnosing early melanoma metastases.
Topics: Animals; Astatine; Humans; Iodine Radioisotopes; Melanoma; Methylene Blue; Radionuclide Imaging; Skin Neoplasms | 1996 |
211At-methylene blue for targeted radiotherapy of disseminated melanoma: microscopic analysis of tumour versus normal tissue damage.
The present stage of our preclinical investigations of targeted radiotherapy for melanoma with 3,7-(dimethylamino)phenazathionium chloride [methylene blue (MTB)] labelled with astatine-211 (211At), an alpha-particle emitter, concerns toxicity of the treatment, as well as macro- and microscopic evaluation of its efficacy. Fragments of two human melanoma xenografts, pigmented HX118 and non-pigmented HX34 (used as a control), were implanted s.c. into nude mice subsequently treated with two doses of 211At-MTB injected i.v. Alterations in tumour growth rate were related to microscopic damage caused by 211At-MTB to the lesions, as determined by light microscopy using histopathological techniques. 211At-MTB-dependent growth inhibition of pigmented melanoma occurred either instantly or as a gradual reduction in the tumour growth rate. At a later stage, lesions that ceased to grow immediately consisted of quiescent, heavily pigmented tumour cells, as well as advanced fibrosis, and were extensively infiltrated by melanin-laden phagocytes. Large, unresorbed and often calcified necrotic deposits characterised the tumours responding gradually to the treatment. 211At-MTB remained non-toxic in normal organs. Only a relative number of small lymphocytes in the groin lymph nodes in a minority of animals was temporarily reduced, most often in conjunction with the treatment of pigmented tumours. The data demonstrated a high therapeutic effectiveness of 211At-MTB towards pigmented melanoma at the expense of negligible injury to normal tissues, and revealed that the macroscopic determination of tumour growth rate often underestimated an efficacy of the applied treatment. Topics: Animals; Astatine; Drug Carriers; Female; Humans; Lymph Nodes; Melanoma; Methylene Blue; Mice; Mice, Nude; Neoplasm Transplantation; Radiation Injuries; Radiotherapy; Skin Neoplasms; Thyroid Gland; Transplantation, Heterologous | 1996 |
Preparation and preliminary evaluation of 4-[211At]astato-N-piperidinoethyl benzamide.
The potential therapeutic agent, 4-[211At]astato-N-piperidinoethyl benzamide (4-APAB) was synthesized via a halodestannylation reaction. Radiochemical yields were 69% for a 5 min reaction and reached 74% by 25 min, whereas 82% radiochemical yields were obtained under similar reaction conditions for radioiodination. A simplified procedure was adopted for the purification of the target compound. In vitro binding of 4-APAB to SK-MEL 28 melanoma and D247 glioma cell lines was 20.7 +/- 1.3% and 12.2 +/- 1.3%, respectively. In comparison, binding of 4-[131I]iodo-N-piperidinoethyl benzamide (4-IPAB) to SK-Mel 28 cells was 13.9 +/- 1.9%. Paired label biodistribution studies were performed in normal Balb/c mice using 4-IPAB and 4-APAB. Thyroid uptake at 1, 2, and 6 h was significantly higher for 4-APAB. Differences in liver accumulation between the two compounds were small but statistically significant at most time points. A higher accumulation of 211At compared with 131I was observed in lungs and spleen at all time points studied. These results indicate that 4-APAB is not stable in vivo, suggesting the need for a better sigma receptor ligand for use in 211At. Topics: Animals; Antineoplastic Agents; Astatine; Benzamides; Brain; Cell Line; Cell Membrane; Glioma; Humans; Iodine Radioisotopes; Lung; Melanoma; Mice; Mice, Inbred BALB C; Piperidines; Spleen; Structure-Activity Relationship; Time Factors; Tissue Distribution | 1995 |
Analysis of the therapeutic gain in the treatment of human osteosarcoma microcolonies in vitro with 211At-labelled monoclonal antibody.
Microcolonies were obtained by culturing cells of two human osteosarcoma lines (OHS and KPDX) and one human melanoma line (WIX-c) for either 24 or 72 h. The microcolonies were treated with either alpha-particle radiation emitted by the 211At-labelled monoclonal antibody (MAb) TP-3 or external beam X-rays. Survival of microcolonies was assayed by colony formation. Therapeutic gain factor (TGF) values were calculated for two survival levels, 50% and 20% microcolony regeneration (i.e. at least one cell in 50% or 20% of the colonies survived the treatments). The TGF values were affected by the specific activity of the 211At-MAb conjugate, the antigen expression of the cells and the size and growth pattern of the microcolonies. Treatment with 211At-TP-3 gave TGF values that varied from 1.3 +/- 0.4 to 4.5 +/- 0.7 (mean +/- s.e.). The antigen-rich OHS cell line had on average 1.6 times higher TGF than the antigen-poor KPDX cell line. The TGF increased significantly with colony size for the densely packed colonies of the KPDX cell line but not for the OHS cell line, which had colonies with cells growing in a more scattered pattern. Control experiments with the two non-specific 211At forms, free 211At and 211At-labelled bovine serum albumin, gave TGF values from 0.6 +/- 0.1 to 1.0 +/- 0.3. This study suggests that in vivo evaluation of 211At-MAbs using relevant tumour models is desirable. Topics: Antibodies, Monoclonal; Astatine; Bone Neoplasms; Cell Division; Cell Line; Humans; Immunoglobulin G; Melanoma; Models, Biological; Osteosarcoma; Radioimmunotherapy; Tumor Cells, Cultured; X-Rays | 1994 |
211At-methylene blue for targeted radiotherapy of human melanoma xenografts: treatment of cutaneous tumors and lymph node metastases.
The next stage of our preclinical investigations of targeted radiotherapy for melanoma with 3,7-(dimethylamino)phenazathionium chloride [methylene blue (MTB)] labeled with 211At (alpha particle emitter) concerns the treatment of cutaneous tumors and their metastases. Fragments of two human melanoma xenografts, highly pigmented HX118 and poorly pigmented HX34, implanted s.c. into nude mice, were treated with four doses of 211At-MTB injected i.v. The growth rate of cutaneous tumors and the appearance and size of their lymph node metastases served as criteria of treatment effectiveness. 211At-MTB inhibited the growth of cutaneous tumors in a manner dependent on their pigmentation and initial size. Highly pigmented smaller melanomas were affected by 211At-MTB to a greater extent than poorly pigmented and larger ones. Growth of the smallest HX118 lesions investigated was completely inhibited for 65 days, whereas the growth inhibition of HX34 tumors of the same size lasted 7 days only. 211At-MTB exhibited similar pigmentation-dependent effects toward lymph node metastases. The size of metastatic lesions derived from HX118 xenografts never reached that in control animals during the period of observation, whereas those grown from HX34 xenografts attained control values after a 50-day delay. The results demonstrated the capacity of 211At-MTB to control the growth of cutaneous melanomas and their metastases. Topics: Animals; Astatine; Drug Screening Assays, Antitumor; Female; Humans; Lymphatic Metastasis; Melanoma; Methylene Blue; Mice; Mice, Nude; Neoplasm Transplantation; Skin Neoplasms; Transplantation, Heterologous; Tumor Cells, Cultured | 1992 |
211At-methylene blue for targeted radiotherapy of human melanoma xenografts: treatment of micrometastases.
Treatment of micrometastases of HX34 human melanoma grown as xenografts in nude mice represents an advanced stage of preclinical investigations concerning targeted radiotherapy of this neoplasm using 3,7-(dimethylamino)phenazathionium chloride [methylene blue (MTB) labeled with astatine-211 (211At) (alpha-particle emitter). The therapeutic effectiveness of 211At-MTB administered i.v. was determined by a lung colony assay combined with a search for metastases to organs other than the lungs. A single dose of 211At-MTB lowered the HX34 cell surviving fraction in lungs to below 10% almost independently of the time interval between cell inoculation and radioisotope injection and of 211At-MTB radioactivity within its investigated range. Radiation dose and the time of its administration did, however, influence the size of lung colonies. In contrast, the efficacy of 211At-MTB treatment as assessed by both surviving fraction and colony size was significantly dependent on a number of HX34 cells inoculated initially into mice. These results are explained by a short range of alpha-particles emitted by 211At and a mechanism of growth of lung colonies from tumor cells circulating with blood and blocking lung capillaries. Metastases in organs other than lungs and characteristic of control animals were not found in mice treated with 211At-MTB. The high therapeutic efficacy achieved proved that 211At-MTB is a very efficient scavenger of single melanoma cells distributed through blood and micrometastases with sizes below the limit of clinical detection. Topics: Animals; Astatine; Brachytherapy; Embolism; Humans; Melanoma; Methylene Blue; Mice; Mice, Nude; Neoplasm Metastasis; Neoplasm Transplantation; Pulmonary Circulation; Time Factors | 1990 |