[Expression of somatostatin receptor reporter gene and its correlation with targeted imaging in vivo for detection of pancreas carcinoma].
OBJECTIVE
To evaluate the value of (99 m)Tc-sandostatin scintigraphy in targeted diagnosis of pancreas carcinoma and the correlation with expression of somatostatin receptor (SSTR) reporter gene in tumor tissue.


METHODS
Nude mice bearing human pancreas carcinoma xenograft were established in advance. (99 m)Tc-sandostatin imaging was performed in 18 nude mice and tumor to normal tissue ratio (T/NT) was calculated. mRNA expression of SSTR1, SSTR2 and SSTR5 in tumor tissue was detected by RT-PCR.


RESULTS
Out of 18 nude mice, 13 mice showed intense uptake of (99 m)Tc-sandostatin. Six hours after (99 m)Tc-sandostatin administration, the T/NT ratio was 2.53 +/- 0.84. Five mice showed negative findings, and the T/NT ratio was 1.04 +/- 0.06. Positive correlations were obtained between the T/NT ratio and the expression of SSTR1 and SSTR2 mRNA, especially SSTR2 (r = 0.807, P < 0.01).


CONCLUSIONS
High expression of SSTR1, SSTR2 and SSTR5 mRNA were found in human pancreas tumor xenograft in nude mice, especially SSTR2. There is a significant correlation between the tumor uptake of (99 m)Tc-sandostatin and SSTR2 mRNA level. This approach may allow SSTR-targeted diagnosis and therapy of human pancreas cancer.
Wang
Zi-zheng
ZZ
Nanjing First Hospital Affiliated to Nanjing Medical University, Nanjing 210006, China. zzwang136@yahoo.com.cn
Qu
Wei
W
Wang
Feng
F
Li
Yan
Y
Wang
Shu-kui
SK
Wang
Jia-qiong
JQ
D000818:Animals; D017930:Genes, Reporter / Q000235:genetics*; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D015282:Octreotide / Q000031:analogs & derivatives; D015609:Organotechnetium Compounds; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011877:Radionuclide Imaging; D017481:Receptors, Somatostatin / Q000096:biosynthesis* / Q000235:genetics; D014407:Tumor Cells, Cultured
D015609:Organotechnetium Compounds; D012333:RNA, Messenger; D017481:Receptors, Somatostatin; C101130:somatostatin receptor type 1; C082115:technetium Tc 99m 6-(4-thioureabenzyl)-3,3,9,9-tetramethyl-4,8-diazaundecane-phenylalanine(1)-octreotide; C094573:somatostatin receptor 5; C093733:somatostatin receptor 2; D015282:Octreotide