Tc-99m and Fluorescence-Labeled Anti-Flt1 Peptide as a Multimodal Tumor Imaging Agent Targeting Vascular Endothelial Growth Factor-Receptor 1 / 대한핵의학회잡지

PURPOSE: We developed a Tc-99m and fluorescence-labeled peptide, Tc-99m TAMRA-GHEG-ECG-GNQWFI, to target tumor cells, and evaluated the diagnostic performance as a dual-modality imaging agent for tumor in a murine model.METHODS: TAMRA-GHEG-ECG-GNQWFI was synthesized using Fmoc solid-phase peptide synthesis. Radiolabeling of TAMRA-GHEG-ECG-GNQWFI with Tc-99m was done using ligand exchange via tartrate. Binding affinity and in vitro cellular uptake studies were performed. Gamma camera imaging, biodistribution, and ex vivo imaging studies were performed in murine models with U87MG tumors. Tumor tissue slides were prepared and analyzed with immunohistochemistry using confocal microscopy.RESULTS: After radiolabeling procedures with Tc-99m, Tc-99m TAMRA-GHEG-ECG-GNQWFI complexes were prepared in high yield (> 95%). The K(d) of Tc-99m TAMRA-GHEG-ECG-GNQWFI determined by saturation binding was 29.5 ± 4.5 nM. Confocal microscopy images of U87MG cells incubated with TAMRA-GHEG-ECG-GNQWFI showed strong fluorescence in the cytoplasm. Gamma camera imaging revealed substantial uptake of Tc-99m TAMRA-GHEG-ECG-GNQWFI in tumors. Tumor uptake was effectively blocked by the co-injection of an excess concentration of GNQWFI. Specific uptake of Tc-99m TAMRA-GHEG-ECG-GNQWFI was assessed by biodistribution, ex vivo imaging, and immunohistochemistry stain studies.CONCLUSION: In vivo and in vitro studies revealed substantial and specific uptake of Tc-99m TAMRA-GHEG-ECG-GNQWFI in tumor cells. Tc-99m TAMRA-GHEG-ECG-GNQWFI could be a good candidate dual-modality imaging agent for tumors.

Genetic variability of calpastatin and calpain genes in Iranian Zel sheep using PCR-RFLP and PCR-SSCP methods

The genotypes for calpastatin [CAST] and calpain [CAPN] loci were determined by PCR-RFLP and PCRSSCP methods. Blood samples were collected from 200 pure-bred Zel sheep from Shirang's Zel sheep Breeding Station located in south-west of Golestan, Iran. Extraction of genomic DNA was performed based on the modified salting out method. Based on results, two investigated loci were polymorphic and had different gene variants. Heterozygosis was low for both loci. Chi-square test confirmed Hardy-Weinberg equilibrium only in CAST locus using SSCP method. Detected polymorphisms and associations of genetic variation with meat production and tenderness may help to find the effective genotypes of Zel sheep for the economic traits

Solid-phase synthesis and in vitro activity research of tumor-targeting cell-penetrating peptide / 南方医科大学学报

<p><b>OBJECTIVE</b>To synthesize a tumor-targeting cell-penetrating peptide (CPP) and evaluate its biological activity and cytotoxicity in vitro.</p><p><b>METHODS</b>With fluorenylmethyloxycarbonyl (Fmoc) as the protective group of α-amino acid, the tumor-targeting CPP were synthesized with stepwise amino acid extension using solid-phase synthesis method. 5-carboxytetramethylrhodamine was added for fluorescence labeling in the presence of the coupling agents HATU and DMF. The purity of the CPP was measured by high-performance liquid chromatography and its molecular weight measured by mass spectrometry. Fluorescence microscope was used to assess the cell-penetrating activity?of the CPP in hepatocellular carcinoma cell lines SMMC-7721 and normal hepatocellular cell lines LO2. The growth activity of CPP-treated SMMC-7721 cells was measured by MTT assay.</p><p><b>RESULTS</b>With a purity of 96.05% and a relative molecular mass of 3504.9, the synthesized CPP showed no translocation activity in normal hepatocellular cell lines LO2, but showed strong ability to translocate into SMMC-7721 cells without affecting the biological activity of the cells.</p><p><b>CONCLUSION</b>Using Fmoc solid-phase synthesis method, we have successfully synthesized the CPP with tumor-targeting activity.</p>

Synthesis and activity of ACE inhibitory peptides / 药学学报

To find anti-hypertensive lead drug, angiotensin converting enzyme (ACE) inhibitory peptides were synthesized and their effects on inhibiting ACE activity were investigated. ACE inhibitory peptides were synthesized via Fmoc solid-phase synthesis, isolated and purified through reversed phase high-performance liquid chromatography (RP-HPLC), and identified by mass spectrometry. A RP-HPLC analysis method was used to test ACE inhibitory activity in vitro of these ACE inhibitory peptides. Six octapeptides were successfully synthesized, and the analytical results of mass spectrum were consistent with their theoretically calculated data. Among these synthetic octapeptides, the anti-SARS (severe acute respiratory syndromes) octapeptide had the most obvious ACE inhibitory activity with an IC50 value of 3.4 x 10(-5) mol x L(-1). So octapeptide AVLQSGFR-OH (anti-SARS peptide) was found to be the strongest candidate for potential development as an anti-hypertensive drug and had the implication of further study.

Synthesis and biological activities of beta-chain fragments of hemoglobin / 药学学报

To investigate the angiotensin I-converting enzyme (ACE) inhibitory activity of beta-chain hemoglobin fragments, 17 fragments were synthesized by microwave-assisted solid-phase synthesis method. Wang resin or Trt(2-Cl) resin, Fmoc and HBTU-HOBt were used as solid carrier, N-terminal amino acid protecting groups and coupling reagents, respectively. The ACE inhibitory, alpha-glucosidase inhibitory, antibacterial and antitumor activities of the synthesized fragments were assayed. In vitro, Val-Val-Tyr-Pro-Trp-Thr showed high ACE inhibitory activity (IC50 = 7.42 micromol x L(-1)). The results indicate that there are two active sites in Val-Val-Tyr-Pro-Trp-Thr-Gln-Arg-Phe, one consists of Val-Val-, and the other -Gln-Arg-Phe. Peptides showed high ACE inhibitory activity when the N-terminal was hydrophobic amino acid such as Val and C-terminal tripeptide contained Phe, Trp or Arg. Some of the fragments showed low a-glucosidase inhibitory activity. No antibacterial activity or antitumor activity was detected in vitro. The results indicate that these peptides have a potential antihypertensive effect and possible application in the treatment of hypertension.