Lequoy M, Desbois-Mouthon C, Wendum D, Gupta V, Blachon J, Scatton O, Dumont S, Bonnemaire M, Schmidlin F, Rosmorduc O, Fartoux L

AIMS To investigate the status of somatostatin receptors (SSTRs) in resected hepatocellular carcinoma (HCC).

METHODS AND RESULTS transcript and protein levels of SSTR2, SSTR3 and SSTR5 were investigated, by real-time PCR and manual and automated immunohistochemistry (IHC) in 53 resected HCC and paired nontumour tissues. SSTR1, SSTR4, SSTR5TMD4 and SSTR5TMD5 were analyzed by real-time PCR. SSTR3 and SSTR5 transcripts were expressed in ~25% of tumours but not in adjacent nontumour tissues. SSTR1 and SSTR2 transcripts were overexpressed in 42% and 32% of tumours, respectively. SSTR4, SSTR5TMD4 and SSTR5TMD5 were not detected. Membrane staining for SSTR2 was detected in 38% of tumours while SSTR5 protein was detectable in only 11% of HCC. SSTR3 protein was detected in the majority of HCC and adjacent nontumour liver but membrane staining was less than 20% of HCC. Results obtained from the two IHC methods were highly correlated (p<0.0001). Statistical analyses also showed a positive correlation between SSTR2 membrane staining and cytokeratin-19 expression (p=0.04), serum alpha-fetoprotein level (p=0.002) and poor differentiation (p=0.05).

CONCLUSIONS Membrane SSTR2 is detected reliably in HCC by IHC and is a potential therapeutic target as it is coexpressed with poor prognosis markers. 

DocGuide