No loss of sst receptors gene expression in advanced stages of colorectal cancer

As demonstrated by several studies, the pan-inhibitory peptide somatostatin (SS) is implicated in a large variety of physiological processes in the ga strointestinal tractus, SS inhibits hormonal and gastric acid secretions, a nd decreases gastric and intestinal motility, mesenteric blood Row and inte stinal absorption. In vitro and in vivo studies showed also that the antipr oliferative potency of SS analogs may be a target to improve the prognosis of colorectal cancer. Here we report the expression profile of the five SS receptor subtypes (hsst 1-5) mRNAs in a large set of tumoral and normal col on. Using reverse transcription-PCR, we showed that hsst5, hsst1 and hsst2 mRNA subtypes were the most frequently expressed hsst mRNA subtypes in norm al and pathological colon. Interestingly, we found that the frequency of hs st5 mRNA expression in the left colon was significantly higher in tumors th an in normal samples: 81.2% (13/16) and 36.4% (4/11) respectively (0.025 > p > 0.01, chi(2) test with Yates' correction). We did not find any influenc e of Dukes' stage on hsst mRNAs expression. Of interest, no loss of hsst2 a nd hsst5 mRNA expression in advanced stages was noted. Some differences in the frequency of expression of hsst mRNAs according to the origin of the ti ssue (left or right colon) were evident. The expression of hsst5 and hsst2 mRNA in advanced colorectal carcinoma associated with the development of ne w SS analogs boost the relevance of colorectal cancer treatment by somatost atin analogs.