Xie Yong-Mei, Yan Lu-Nan, Wei Bing, Guo Mei-Mei, Tang Cheng-Wei
Department of Gastroenterology, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041, P. R. China.
Ai Zheng. 2007 Jul;26(7):688-92.
BACKGROUND & 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.
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).
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.
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.
生长抑素类似物（SSTA）对肝细胞癌（HCC）的生长具有抑制作用。然而，生长抑素受体（SSTR）在HCC中的表达仍不清楚，其与血清甲胎蛋白（AFP）的相关性也尚未得到研究。本研究旨在调查HCC中SSTR1、SSTR2、SSTR3、SSTR4和SSTR5亚型的表达，并探讨它们与血清AFP浓度的相关性。
分别采用逆转录-聚合酶链反应（RT-PCR）和免疫组织化学（IHC）检测40例HCC标本和40例肝硬化标本中SSTR1、SSTR2、SSTR3、SSTR4和SSTR5亚型的mRNA和蛋白表达。采用酶联免疫吸附测定（ELISA）法检测40例HCC患者肝组织和外周血中的AFP水平。
HCC中SSTR1、SSTR2、SSTR3、SSTR4和SSTR5蛋白的阳性率分别为47.5%、70.0%、50.0%、65.0%和67.5%，肝硬化组织中分别为55.0%、67.5%、52.5%、60.0%和47.5%。HCC中SSTR1、SSTR2、SSTR3、SSTR4和SSTR5的蛋白水平明显高于肝硬化组织。HCC中SSTR1、SSTR2、SSTR3、SSTR4和SSTR5的表达与血清AFP水平呈曲线相关（r分别为0.882、0.901、0.877、0.854、0.903，P<0.05）。血清AFP水平在200 - 800 ng/ml之间与HCC中SSTRs的高表达相关；该范围以下或以上的血清AFP水平与SSTRs的低表达相关。
约60%的HCC组织表达SSTRs；HCC中SSTRs的蛋白水平远高于肝硬化组织。血清AFP水平在200 - 800 ng/ml之间的HCC患者可能是SSTA治疗的良好候选者。
