Study Of^99m Tc-LHRH In Tumor Receptor Imaging

Objective：To detect GnRH （gonadotropin-releasing hormone, LHRH） in the relevanttumor tissue and normal tissues and organs in vivo expression; To explore the method ofdirect radiolabeling of gonadotrophin releasing hormone（LHRH）by^99mTc withrelatively high radiochemical purity and stability, screening the best labeling conditions,to establish a simple and reliable method of preparation of^99mTc-LHRH; Meanwhile,the detection of radioisotope labeled LHRH distribution in mice, LHRH receptorimaging for the study and treatment of cancer basis. Methods:①Byimmunohistochemical staining was used （Elivision France） test in23patients with HCC,20patients with breast,10prostate cancer,20patients with lung cancer,20endometrialcancer tumor cells and normal tissue LHRH-R De Biaoda levels; Pre-tin method②Usedirect labeling of LHRH, marking completion of saline or human serum were added atroom temperature, the paper chromatography measured at different time and calculatethe rate of labeled product and the radiochemical purity of labeled, in vivo observationof its stability, and comparative analysis of selected optimal condition;③Rat pituitarycell membrane protein, the product of in vitro radio-receptor marker analysis, throughthe saturation and inhibition experiments, to test its receptor binding activity;○4Ch-T method labeled125I-LHRH, tail vein injection of normal mice at different timewere killed, blood and major organs were determined and calculated per gramOrganization percentage injected dose rate （%ID/g）. Results: Detected byimmunohistochemistry in23cases of HCC in the LHRH-positive rate was82.61%, thecorresponding normal tissues, the positive rate of15%;20cases of breast cancerpositive rate of95%, the corresponding normal tissues, the positive rate was20%;10cases of prostate cancer positive rate of70%, the corresponding normal tissues, thepositive rate of40%;20cases of lung cancer positive rate of85%, the correspondingnormal tissues, the positive rate of15.79%;20cases of endometrial cancer positive rateof80%in the corresponding normal tissues was16.67%positive.^99mTc-LHRH mark was97.9%¹00.0%, the radiochemical purity of93.9%-96.4%, marking the reactiongel content of less than5%; Great product receptor marker analysis showed that:^99mTc-LHRH with saturable receptor binding characteristics and inhibition, and highaffinity, RT=23.2174pmol, KD=0.4348nmol; intravenous injection of131I-LHRHwithin72h after the mice rapidly cleared the blood radioactivity, the major radioactiveaccumulation in the liver and kidneys and by the liver, renal clearance, and other tissuesand organs of the radioactivity gradually decreased with time. Conclusions:①Theliver, lung, breast, prostate, endometrial cancer exists LHRHR;②^99mTc-LHRHpreparation is simple, rapid, radiochemical purity product obtained higher marks, betterstability, no further purification;③LHRH by^99mTc labeled, still has a high receptorbinding ability, biological activity;○4Labeled products with a ideal and realisticdynamics show animals, there is hope, as with the clinical value of imaging agent ofgonadotropin-releasing hormone receptors.