To investigate a new kind of tumor tracer ^99mTc-YIGSR developed from a five amino structure （YIGSR） of the Laminin -chain, which can bind to the laminin receptors of tumor specifically, and radiolabeled with MAG3. ...To investigate a new kind of tumor tracer ^99mTc-YIGSR developed from a five amino structure （YIGSR） of the Laminin -chain, which can bind to the laminin receptors of tumor specifically, and radiolabeled with MAG3. （1） Preparation of the ^99mTc-YIGSR probe： with S-Acetly-NH3- MAG3as the chelator and with proper reductants YIGSR was labeled with ^99mTc;（2） Cell culture and viability measurement： EAC was maintained in RPMI 1640 supplemented with calf serum; the trypan blue exclusion was applied to calculate the cell viability; （3） Study of the cell dynamic： The EAC＇s uptake of ^99mTc-YIGSR and ^99mTc-MIBI was observed at 37℃ and 22 ℃, respectively. （1） The labeling efficiencies of ^99mTc-YIGSR and^99mTc-MIBI were （62±3） % and （96±2） %, respectively; （2） The cell viability was declined with time of incubation; （3） At 37 ℃, the EAC＇S uptake of ^99mTc YIGSR and^99mTc-MIBI reached the peak of （43. 16±2.4） % and （24.4±1.8） % at 60 min, respectively; and at 22 ℃, the highest uptake was （26.5±2. 1） % and （9.47±1.9） % at 60 min, respectively. The in vitro study suggests that ^99mTc-YIGSR is superior to ^99mTc-MIBI in cell uptake and has potential value in tumor imaging.展开更多
The validity of ^99mTc-YIGSR, a novel receptor radio-tracer, in imaging the Ehrlich ascites tumor was evaluated. YIGSR, a pentapeptide of laminin, was labeled with ^99mTc by using a bifunctional chelator S-Acetly-NH3-...The validity of ^99mTc-YIGSR, a novel receptor radio-tracer, in imaging the Ehrlich ascites tumor was evaluated. YIGSR, a pentapeptide of laminin, was labeled with ^99mTc by using a bifunctional chelator S-Acetly-NH3-MAG3. The MIBI was labeled with ^99mTc by following the kit instruction. The mice of tumor group were intravenously injected 1-2 mCi of ^99mTc-YIGSR or ^99mTc-MIBI via caudal vein, immobilized and imaged under a Gamma camera. The same procedure was performed in mice of blockade group, in which the unlabeled YIGSR was previously injected to block the receptor-recognition sites, and inflammation group serving as control. The reverse-phase Sep-Pak C18 chromatogram was found to have an essentially complete conjugation between YIGSR and S-Acetly-NH3-MAG3. The conjugated YIGSR could be radio-labeled successfully with ^99mTC at room temperature and neutral pH, with a radio-labeling yield of 62%. Without the chelator S-Acetly-NH3-MAG3, the YIGSR was labeled with ^99mTc at an efficiency of 4%. The imagological study revealed obvious tumor accumulation of ^99mTc-YIGSR 15 min after the injection, and the uptake peaked after 3 h with a tumor-to-muscle ratio （T/M） of 11.36. The radio-tracer was slowly cleared up and resulted in a T/M of 3.01 at the 8th h after the injection. As for blocked group, the tumor uptake of radiotracer was significantly lower, with the highest T/M being 4.61 after 3 h and 0.89 after 8 h. The T/M was 3.72 at the 3rd h and 1.29 at the 8th h after the ^99mTc-YIGSR injection in the inflammatory group. The T/M was significantly higher in tumor group than in inflammatory group or control group （P〈0.001）. In the ^99mTc-MIBI group, the T/M was 1.40 at the 3rd h and 0.55 at the 8th h after the injection, which showed a significant difference as compared with ^99mTc-YIGSR （P〈0.001）. It is concluded that YIGSR can be successfully radiolabelled by using S-Acetly-NH3-MAG3. ^99mTc-YIGSR has many advantages in tumor imaging, such as quick and clear visualization, high sensitivity and specificity, and satisfactory target/non-target ratio （N/NT）. It promises to be tumor radio-tracer.展开更多
Background The YIGSR is a pentapeptide, from the laminin-1 of the β1 chain, which can mediate cell adhesion and bind the 67 kD laminin receptor. The purpose is to evaluate the usefulness of 99m Tc-YIGSR, a novel ...Background The YIGSR is a pentapeptide, from the laminin-1 of the β1 chain, which can mediate cell adhesion and bind the 67 kD laminin receptor. The purpose is to evaluate the usefulness of 99m Tc-YIGSR, a novel tumour radiotracer, in the receptor imaging of Ehrlich ascites tumour. Methods Using S-Acetly-NH_3-MAG_3 as chelate, YIGSR, a pentapeptide from laminin, was tagged with 99m Tc. 99m Tc-YIGSR was detected in the tumour group bearing Ehrlich ascites tumour and blocked group. Tumour, normal, inflammatory and blocked groups were imaged. Results Through reverse phase Sep-Pak C_ 18 chromatogram, it was revealed that YIGSR could conjugate with S-Acetly -NH_3-MAG_3, and be radiolabelled at room temperature and neutral pH with a radiolabelling yield of 62%, and of 4% without chelate. 99m Tc-YIGSR was rapidly cleared from kidney, then liver. The imaging findings showed tumour tissue accumulated initial radioactivity at fifteen minutes after injection in the tumour group, and the uptake increased to peak at three hours with a tumour/muscle ratio (T/M) of 11.36, then cleared slowly to a T/M of 7.50 at eight hours. The tumour uptake of radiotracer in blocked group was significantly lower with T/M of 4.61 at three hours and 0.89 at eight hours. The T/M was only 3.72 at three hours and 1.29 at eight hours after injection in inflammatory group. Compared with inflammatory group and control obstructive group, the ratio of T/M in tumour group was significantly different ( P <0.001). Conclusions Using S-Acetly-NH_3-MAG_3, we radiolabelled YIGSR with 99m Tc. 99m Tc-YIGSR possesses many merits of tumour imaging: rapid visualization, high sensitivity and specificity, and satisfactory target/nontarget ratio. Our data suggest 99m Tc-YIGSR is a promising tumour radiotracer.展开更多
文摘To investigate a new kind of tumor tracer ^99mTc-YIGSR developed from a five amino structure （YIGSR） of the Laminin -chain, which can bind to the laminin receptors of tumor specifically, and radiolabeled with MAG3. （1） Preparation of the ^99mTc-YIGSR probe： with S-Acetly-NH3- MAG3as the chelator and with proper reductants YIGSR was labeled with ^99mTc;（2） Cell culture and viability measurement： EAC was maintained in RPMI 1640 supplemented with calf serum; the trypan blue exclusion was applied to calculate the cell viability; （3） Study of the cell dynamic： The EAC＇s uptake of ^99mTc-YIGSR and ^99mTc-MIBI was observed at 37℃ and 22 ℃, respectively. （1） The labeling efficiencies of ^99mTc-YIGSR and^99mTc-MIBI were （62±3） % and （96±2） %, respectively; （2） The cell viability was declined with time of incubation; （3） At 37 ℃, the EAC＇S uptake of ^99mTc YIGSR and^99mTc-MIBI reached the peak of （43. 16±2.4） % and （24.4±1.8） % at 60 min, respectively; and at 22 ℃, the highest uptake was （26.5±2. 1） % and （9.47±1.9） % at 60 min, respectively. The in vitro study suggests that ^99mTc-YIGSR is superior to ^99mTc-MIBI in cell uptake and has potential value in tumor imaging.
基金This project was supported by a grant from the National Natural Sciences Foundation of China (No 30400170)
文摘The validity of ^99mTc-YIGSR, a novel receptor radio-tracer, in imaging the Ehrlich ascites tumor was evaluated. YIGSR, a pentapeptide of laminin, was labeled with ^99mTc by using a bifunctional chelator S-Acetly-NH3-MAG3. The MIBI was labeled with ^99mTc by following the kit instruction. The mice of tumor group were intravenously injected 1-2 mCi of ^99mTc-YIGSR or ^99mTc-MIBI via caudal vein, immobilized and imaged under a Gamma camera. The same procedure was performed in mice of blockade group, in which the unlabeled YIGSR was previously injected to block the receptor-recognition sites, and inflammation group serving as control. The reverse-phase Sep-Pak C18 chromatogram was found to have an essentially complete conjugation between YIGSR and S-Acetly-NH3-MAG3. The conjugated YIGSR could be radio-labeled successfully with ^99mTC at room temperature and neutral pH, with a radio-labeling yield of 62%. Without the chelator S-Acetly-NH3-MAG3, the YIGSR was labeled with ^99mTc at an efficiency of 4%. The imagological study revealed obvious tumor accumulation of ^99mTc-YIGSR 15 min after the injection, and the uptake peaked after 3 h with a tumor-to-muscle ratio （T/M） of 11.36. The radio-tracer was slowly cleared up and resulted in a T/M of 3.01 at the 8th h after the injection. As for blocked group, the tumor uptake of radiotracer was significantly lower, with the highest T/M being 4.61 after 3 h and 0.89 after 8 h. The T/M was 3.72 at the 3rd h and 1.29 at the 8th h after the ^99mTc-YIGSR injection in the inflammatory group. The T/M was significantly higher in tumor group than in inflammatory group or control group （P〈0.001）. In the ^99mTc-MIBI group, the T/M was 1.40 at the 3rd h and 0.55 at the 8th h after the injection, which showed a significant difference as compared with ^99mTc-YIGSR （P〈0.001）. It is concluded that YIGSR can be successfully radiolabelled by using S-Acetly-NH3-MAG3. ^99mTc-YIGSR has many advantages in tumor imaging, such as quick and clear visualization, high sensitivity and specificity, and satisfactory target/non-target ratio （N/NT）. It promises to be tumor radio-tracer.
文摘Background The YIGSR is a pentapeptide, from the laminin-1 of the β1 chain, which can mediate cell adhesion and bind the 67 kD laminin receptor. The purpose is to evaluate the usefulness of 99m Tc-YIGSR, a novel tumour radiotracer, in the receptor imaging of Ehrlich ascites tumour. Methods Using S-Acetly-NH_3-MAG_3 as chelate, YIGSR, a pentapeptide from laminin, was tagged with 99m Tc. 99m Tc-YIGSR was detected in the tumour group bearing Ehrlich ascites tumour and blocked group. Tumour, normal, inflammatory and blocked groups were imaged. Results Through reverse phase Sep-Pak C_ 18 chromatogram, it was revealed that YIGSR could conjugate with S-Acetly -NH_3-MAG_3, and be radiolabelled at room temperature and neutral pH with a radiolabelling yield of 62%, and of 4% without chelate. 99m Tc-YIGSR was rapidly cleared from kidney, then liver. The imaging findings showed tumour tissue accumulated initial radioactivity at fifteen minutes after injection in the tumour group, and the uptake increased to peak at three hours with a tumour/muscle ratio (T/M) of 11.36, then cleared slowly to a T/M of 7.50 at eight hours. The tumour uptake of radiotracer in blocked group was significantly lower with T/M of 4.61 at three hours and 0.89 at eight hours. The T/M was only 3.72 at three hours and 1.29 at eight hours after injection in inflammatory group. Compared with inflammatory group and control obstructive group, the ratio of T/M in tumour group was significantly different ( P <0.001). Conclusions Using S-Acetly-NH_3-MAG_3, we radiolabelled YIGSR with 99m Tc. 99m Tc-YIGSR possesses many merits of tumour imaging: rapid visualization, high sensitivity and specificity, and satisfactory target/nontarget ratio. Our data suggest 99m Tc-YIGSR is a promising tumour radiotracer.
