[Correlation of somatostatin receptor expression in human hepatocellular carcinoma tissue to serum alpha-fetoprotein concentration].
OBJECTIVE
Somatostatin analogue (SSTA) has inhibitory effect on the growth of hepatocellular carcinoma (HCC). However, the expression of somatostatin receptor (SSTR) in HCC is still unclear and its correlation to serum alpha-fetoprotein (AFP) has not yet been explored. This study was to investigate the expression of SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5 subtypes in HCC, and explore their correlations to serum AFP concentration.


METHODS
The mRNA and protein expression of SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5 subtypes in 40 specimens of HCC and 40 specimens of liver cirrhosis were detected by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC), respectively. AFP levels in liver tissues and peripheral blood of the 40 HCC patients were measured with enzyme-linked immunosorbent assay (ELISA).


RESULTS
The positive rates of SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5 proteins were 47.5%, 70.0%, 50.0%, 65.0%, and 67.5% in HCC, and 55.0%, 67.5%, 52.5%, 60.0%, and 47.5% in liver cirrhosis tissues, respectively. The protein levels of SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5 were markedly higher in HCC than in liver cirrhosis tissues. The expression of SSTR1, SSTR2, SSTR3, SSTR4, and SSTR5 in HCC had curilinear correlations with serum AFP levels (r = 0.882, 0.901, 0.877, 0.854, 0.903, respectively, P < 0.05). Serum AFP levels ranging between 200-800 ng/ml were associated with high expression of SSTRs in HCC; serum AFP levels below or over that range were associated with low expression of SSTRs.


CONCLUSIONS
About 60% of the HCC tissues express SSTRs; the protein levels of SSTRs are much higher in HCC than in liver cirrhosis tissues. HCC patients with serum AFP level ranging between 200-800 ng/ml may be good candidates for SSTA therapy.
Xie
Yong-Mei
YM
Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, P. R. China.
Yan
Lu-Nan
LN
Wei
Bing
B
Guo
Mei-Mei
MM
Tang
Cheng-Wei
CW
D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008103:Liver Cirrhosis / Q000097:blood / Q000378:metabolism; D008113:Liver Neoplasms / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D017481:Receptors, Somatostatin / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000509:alpha-Fetoproteins / Q000378:metabolism*
D012333:RNA, Messenger; D017481:Receptors, Somatostatin; D000509:alpha-Fetoproteins; C103631:somatostatin receptor 3; C098681:somatostatin receptor subtype-4; C101130:somatostatin receptor type 1; C094573:somatostatin receptor 5; C093733:somatostatin receptor 2