In vitro distribution and receptor scintigraphy of somatostatin receptor 2 subtypes in small cell lung cancer / 肿瘤

ABSTRACT

Objective: To investigate the distribution of somatostatin receptor 2 subtype (SSTR2) in small cell lung cancer (SCLC) in vitro and the value of 99mTc-octreotide scintigraphy for SCLC diagnosis in vivo. Methods: The distribution of SSTR2 was detected by electron microscopic autoradiography (EMR) using 125I octreotide. 99mTc-octreotide (0.15 mL, 16.8 MBq) was injected into nude mice via tail veins and 99mTc-octreotide scintigraphy was observed. Results: The tagged rates of cellular sliver grains were 95.0% (19/20) and 85.0% (16/20) at 30 min and 120 min, respectively. The difference was significant (P < 0.05). Sliver grains were distributed in the membranes at 30 min and located in the nucleolus and cytoplasm at 120 min. The numbers of sliver grains in the control group (addition of over Tyr 3-octreotide) were remarkably less than those of group 30 min and 120 min. The scintigraphy of the tumors in 5 nude mice was positively displayed at 4 h postinjection of 99mTc octreotide. Conclusions: SSTR2 is over-expressed in SCLC. Radiolabeled octreotide scintigraphy may become a novel detection method for early diagnosis of SCLC.