6-hydrazinopyridine-3-carboxylic-acid and Breast-Neoplasms

Topics: Adult; Aged; Animals; Breast Neoplasms; Chemistry Techniques, Synthetic; Female; Half-Life; Humans; Hydrazines; Melanoma; Mice; Middle Aged; Nicotinic Acids; Organotechnetium Compounds; Peptides, Cyclic; Radiochemistry; Single Photon Emission Computed Tomography Computed Tomography; Tissue Distribution

Noninvasive quantification of chemokine receptor 4 (CXCR4) expression could serve as a prognostic indicator and may be of value for the design of personalized therapies and posttreatment monitoring. The objective of the present study was to assess the use of (99m)Tc-radiolabeled small-interference RNA (siRNA) targeting CXCR4 to detect CXCR4 expression in vivo.. CXCR4 siRNAs were radiolabeled with (99m)Tc using the bifunctional chelator hydrazinonicotinamide (HYNIC), and the labeling efficiency, specific activity and radiochemical purity were determined. The stability of the probe in serum was assessed by measuring its radiochemical purity and inhibitory activity by RT-PCR and western blotting. Biodistribution studies and static imaging were performed in MDA-MB-231 tumor-bearing mice.. Radiochemical purity remained highly stable in PBS and fresh human serum at room temperature and at 37 °C. Radiolabeled siRNA1 showed strong inhibitory effects similar to those of unlabeled siRNA1 on both CXCR4 messenger RNA (mRNA) and protein in vitro. The excretion of the probe occurred mainly through the liver and kidneys. Tumors were clearly visualized at 1-10 h after injection of the probe, but not after injection of the control probe.. (99m)Tc-labeled CXCR4 siRNA1 shows tumor-specific accumulation and could be a promising strategy for the visualization of CXCR4 expression in human breast cancer.

Topics: Animals; Breast Neoplasms; Cell Line, Tumor; Female; Humans; Hydrazines; Mice, Inbred BALB C; Molecular Imaging; Nicotinic Acids; Oligonucleotides, Antisense; Radiopharmaceuticals; Receptors, CXCR4; RNA, Small Interfering; Technetium; Tissue Distribution; Xenograft Model Antitumor Assays

The development of radioimmunotherapy has provided an impressive alternative approach in improving trastuzumab therapy. However, the mechanisms of trastuzumab and radiation treatment combined to increase therapeutic efficacy are poorly understood. Here, we try to examine the efficacy of cytotoxicity and apoptosis induction for (188)Re-HYNIC-trastuzumab in cancer cell lines with various levels of Her2.. Fluorescence flow cytometry was used to detect the alterations of apoptosis induction after (188)Re-HYNIC-trastuzumab treatment in two breast cancer cell lines with different levels of HER2 (BT-474 and MCF-7) and a colorectal carcinoma cell line (HT-29) for control.. Our results indicated that (188)Re-HYNIC-trastuzumab led to cell death of breast cancer cells specifically in HER2 level-dependent and radioactivity dose-dependent fashions. In BT-474 cells, 370 kBq/ml of (188)Re-HYNIC-trastuzumab enhanced the cytotoxicity to a level nearly 100-fold that of trastuzumab-alone treatment. The results also revealed that the mitochondria-dependent pathway attenuated irradiation-induced apoptosis in HER2-expressing breast cancer cells after (188)Re-HYNIC-trastuzumab treatment. In contrast, only after 48 h of (188)Re-HYNIC-trastuzumab treatment, BT-474 cells exhibited typical apoptotic changes, including exposure of phospholipid phosphatidylserine on the cell surface, or fragmented DNA formation, in a radioactivity dose-dependent manner.. Briefly, our study demonstrates that (188)Re-labeled HYNIC-trastuzumab not only enhances cell death in a radioactivity dose-dependent fashion, but may also prolong the effects of apoptosis involved with the mitochondria-dependent pathway in HER2-overexpressing breast cancer cells. It is possible that the (188)Re-HYNIC-trastuzumab treatment induced a second round of apoptosis to prolong the effects of cell kill in these cancer cells. These data revealed that (188)Re-HYNIC-trastuzumab has the potential for use as a therapeutic radiopharmaceutical agent in HER2-overexpressing breast cancer cell treatment.

Topics: Antibodies, Monoclonal, Humanized; Antineoplastic Agents; Apoptosis; Breast Neoplasms; Cell Line, Tumor; Colorectal Neoplasms; Dose-Response Relationship, Radiation; Flow Cytometry; Humans; Hydrazines; Membrane Potential, Mitochondrial; Nicotinic Acids; Radioimmunotherapy; Radioisotopes; Radiopharmaceuticals; Receptor, ErbB-2; Rhenium; Trastuzumab

Bombesin (BBN) is a tetradecapeptide that binds specifically to gastrin-releasing peptide receptors in humans. These receptors are over-expressed in several forms of cancer; radiolabeled BBN could therefore be used to detect such cancers. However, the degradation of peptides is a critical issue in the development of tumor tracers. Liposomes can be used to overcome this problem and improve the uptake of tracers by tumors. Therefore, the purpose of this study was to prepare and characterize long-circulating and pH-sensitive liposomes (SpHL) containing 99mTc-HYNIC-βAla-Bombesin(7-14) (99mTc-BBN(7-14). In addition, the ability of this system to identify human breast cancer tissue was evaluated using biodistribution studies and scintigraphic images. Long-circulating and pH-sensitive liposomes (SpHL) were prepared and freeze-dried in the presence of cryoprotectants (glucose, mannitol, and trehalose). They were subsequently reconstituted with a solution of 99mTc-HYNIC-βAla-Bombesin(7-14) (99mTc-BBN(7-14)). The liposomes were evaluated for size, encapsulation percentage, radiotracer leakage, and storage stability. In addition, in vivo studies were performed in breast tumor-bearing nude mice. Liposomes in the presence of glucose (SpHLG), exhibited a mean diameter of 164.5 ± 6.5 nm and exhibited a 99mTc-BBN(7-14) encapsulation percentage of 30%. In addition, they remained highly stable for up to 120 days of storage. SpHLG- 99mTc-BBN(7-14) showed longer blood circulation than free 99mTc-BBN(7-14), did. The tumor-to-muscle and tumor-to-blood ratios for SpHLG-99mTc-BBN(7-14 were high at 4 h post-injection (9.31%ID/g and 7.93%ID/g, respectively). Furthermore, scintigraphic images revealed a strong signal in the tumor area, indicating tumor specificity of SpHLG-99mTc-BBN(7-14). In summary, SpHLG-99mTc-BBN(7-14) presented characteristics suitable for a diagnostic agent, and is a potential tool for tumor identification.

Topics: Animals; Bombesin; Breast Neoplasms; Drug Compounding; Female; Humans; Hydrazines; Hydrogen-Ion Concentration; Liposomes; Mice; Mice, Inbred C57BL; Mice, Nude; Nicotinic Acids; Organotechnetium Compounds; Peptide Fragments; Radioactive Tracers; Radionuclide Imaging; Tumor Cells, Cultured

In breast cancer, α(ν)β(3) and/or α(ν)β(5) integrins are overexpressed in both endothelial and tumour cells. Radiolabelled peptides based on the Arg-Gly-Asp (RGD) sequence are radiopharmaceuticals with high affinity and selectivity for these integrins. The RGD-dimer peptide (E-[c(RGDfK)]2) radiolabelled with (99m)Tc has been reported as a radiopharmaceutical with a 10-fold higher affinity for the α(ν)β(3) integrin compared with the RGD-monomer. Ethylenediamine-N,N'-diacetic acid (EDDA) is a hydrophilic molecule that may favour renal excretion when used as coligand in the (99m)Tc labelling of hydrazinonicotinamide (HYNIC) peptides and can easily be formulated in a lyophilized kit.. The aim of this study was to establish a biokinetic model for (99m)Tc-EDDA/HYNIC-E-[c(RGDfK)]2 prepared from lyophilized kits and evaluate its dosimetry as a tumour-imaging agent in seven healthy women and three breast cancer patients.. (99m)Tc labelling was performed by adding sodium pertechnetate solution and 0.2 mol/l phosphate buffer (pH 7.0) to a lyophilized formulation containing E-[c(RGDfK)]2, EDDA, tricine, mannitol and stannous chloride. The radiochemical purity was evaluated using reverse-phase high-performance liquid chromatography and instant thin-layer chromatography on silica gel analyses. Stability studies in human serum were carried out using size-exclusion high-performance liquid chromatography. In-vitro cell uptake was tested using breast cancer cells (MCF7, T47D and MDA-MB-231) with blocked and nonblocked receptors. Biodistribution and tumour uptake were determined in MCF7 tumour-bearing nude mice with blocked and nonblocked receptors, and images were obtained using a micro-SPECT/PET/CT. Whole-body images from seven healthy women were acquired at 0.5, 1, 3, 6 and 24 h after (99m)Tc-EDDA/HYNIC-E-[c(RGDfK)]2 administration with radiochemical purities greater than 94%. Regions of interest were drawn around the source organs at each time frame. Each region of interest was converted to activity using the conjugate view counting method. The image sequence was used to extrapolate the (99m)Tc-EDDA/HYNIC-E-[c(RGDfK)]2 time-activity curves of each organ to adjust the biokinetic model and calculate the total number of disintegrations (N) that occurred in the source regions. N data were the input for the OLINDA/EXM code to calculate internal radiation dose estimates. In three breast cancer patients with histologically confirmed cancer, static images were obtained at 1 h in the supine position with hands placed behind the head.. (99m)Tc-EDDA/HYNIC-E-[c(RGDfK)]2 obtained from lyophilized kits demonstrated high stability in human serum and specific cell receptor binding. The biodistribution data from mice showed rapid blood clearance, with both renal and hepatobiliary excretion, and specific binding towards α(ν)β(3) integrins in the MCF7 tumours. In women, the blood activity showed a half-life value of 1.60 min for the fast component (T1/2α = ln2/26.01) and half-life values of 1.0 h for the first slow component (T1/2β = ln2/0.69) and 4.03 h for the second slow component (T1/2γ = ln2/0.16). Images from patients showed an average tumour/heart (blood) ratio of 3.61 ± 0.62 at 1 h. The average equivalent doses calculated for a study using 740 MBq were 4.9, 6.2, 20.7, 34.5 and 57.0 mSv for the liver, intestines, spleen, kidneys and thyroid, respectively, and the effective dose was 6.1 mSv.. All absorbed doses were comparable to those known from most of the (99m)Tc studies. (99m)Tc-EDDA/HYNIC-E-[c(RGDfK)]2 obtained from kit formulations showed high tumour uptake in patients with malignant lesions, making it a promising imaging radiopharmaceutical for targeting site-specific breast cancer. The results obtained in this study warrant further clinical studies to determine the specificity and sensitivity of (99m)Tc-EDDA/HYNIC-E-[c(RGDfK)]2.

Topics: Animals; Breast Neoplasms; Cell Line, Tumor; Dimerization; Edetic Acid; Female; Freeze Drying; Humans; Hydrazines; Mice; Nicotinic Acids; Oligopeptides; Organotechnetium Compounds; Radiochemistry; Radiometry; Tissue Distribution; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Membrane type-1 matrix metalloproteinase (MT1-MMP) expressed on the tumor cell surface activates pro-MMP-2 and pro-MMP-13 to exacerbate the malignancy, suggesting its suitability as a target molecule for diagnosis by in vivo molecular imaging. Thus, we prepared radiolabeled anti-MT1-MMP monoclonal antibody (mAb) as a novel radiolabeled probe for detecting MT1-MMP in vivo and evaluated its usefulness in breast tumor-bearing rodents. (99m)Tc-anti-MT1-MMP mAb was prepared using HYNIC as a bifunctional chelating agent and immunoreactivity was evaluated by flow cytometry. MT1-MMP expression in breast carcinoma cells (rat: Walker-256 and MRMT-1, mouse: FM3A) was measured by Western blotting. In vivo biodistribution was examined for 48 h using tumor-implanted rodents followed by estimation of radiation absorbed by a standard quantitation platform Organ Level Internal Dose Assessment (OLINDA). (99m)Tc-anti-MT1-MMP mAb was obtained with 84% immunoreactivity to MT1-MMP and more than 92% radiochemical purity. MT1-MMP was highly expressed in all malignant cells. Tumor radioactivity increased with time after administration and reached 3 to 5 times higher values at 24 h post-injection than those at 1 h. Other organs, including the stomach, showed decreasing values over time. Tumor to blood ratios increased with time and reached more than 1.3 at 48 h. The effective dose was <5.0 muSv/MBq. The results suggest that (99m)Tc-anti-MT1-MMP mAb is a promising probe for future diagnosis of breast tumors by in vivo nuclear medical imaging.

Topics: Animals; Antibodies, Monoclonal; Biomarkers, Tumor; Blotting, Western; Breast Neoplasms; Cell Line, Tumor; Diagnostic Techniques, Radioisotope; Female; Hydrazines; Matrix Metalloproteinase 14; Mice; Mice, Inbred C3H; Neoplasm Transplantation; Nicotinic Acids; Radionuclide Imaging; Rats; Rats, Sprague-Dawley; Technetium

To investigate the effect of radiolabed mouse double minute 2 (MDM2) antisense oligonucleotide on gene expression in human breast cancer MCF-7 cells, an antisense oligonucleotide (ASON) targeting MDM2 mRNA was synthesized and radiolabeled with 99Tcm. The labeling efficiency, radiochemical purity, and the ability of labeled ASON to hybridize to the sense oligonucleotides (SON) were investigated. To study whether the antisense probe hybridizes to respective sequence on MDM2 mRNA strand after radiolabeling, cells were incubated with radiolabeling oligonucleotides antisense oligonucleotide (0, 100, 500 nm/L) or mismatch oligonucleotide (ASONM) (500 nm/L) for 24 h, in the presence of Lipofectin 2000. RT-PCR and Western blotting was carried out to measure the MDM2 mRNA and protein levels. The antisense oligonucleotide was radiolabeled with the bifunctional chelator HYNIC at the labeling efficiency of 57.2 +/- 2.98% (n = 5) and the mismatch oligonucleotide was 56.3 +/- 3.01% (n = 5). The radiochemical purity was above 95% and labeled antisense oligonucleotide has the ability to hybridize to the sense oligonucleotide. The levels of mRNA and protein have significant differences in different concentration groups. The oligonucleotide can be successfully radiolabeled, and specially hybridized to the MDM2 mRNA and inhibit gene expression intensively as compared to mismatch oligonucleotide. This method will be very useful in the in vivo investigation of tumor targeting.

Topics: Breast Neoplasms; Cell Line, Tumor; Female; Gene Expression; Genes, p53; Humans; Hydrazines; Isotope Labeling; Nicotinic Acids; Oligonucleotides, Antisense; Proto-Oncogene Proteins c-mdm2; RNA, Messenger; Technetium; Tumor Suppressor Protein p53