Session: MON 167-198-Hypothalamus-Pituitary Development & Biology
Poster Board MON-169
The aim of the study was quantitative analysis of somatostatin receptors (SSTR) in CNFAs using real-time RT-PCR and correlation with immunohistochemical profile.
Results: All 69 adenomas, 40 men and 29 women, aged 25–84 years (mean 61.4 +/-1.5, med 63) expressed SSTR1–4 and SSTR5 was expressed in 38 (55 %) of adenomas. High variability of expression for a particular type was present. SSTR1 mRNA was expressed from 909 to 242069, SSTR2 1413–148 681, SSTR3 63–46 914, SSTR4 568–99 227 and SSTR5 mRNA 0–43 777 (all in copies/5μl cDNA). Relative median quantity after normalization to housekeeping gene GUS was 0.65 SSTR1 > 0.54 SSTR2 > 0.26 SSTR4 >0.19 SSTR3 > 0.01 SSTR5. After immunohistochemical analysis, we had 56 gonadotroph, 3 null-cell adenomas, 6 silent corticotroph and 4 plurihormonal tumors. SSTR1-4 expression was not statistically different in regard to histological type of adenoma. SSTR5 was highly expressed in silent corticotroph adenomas (relative median quantity after normalization to housekeeping gene GUS 0.01) than in gonadotroph adenomas (0.14).
Conclusion: A very heterogeneous level of SSTR expression may explain low clinical effectiveness of somatostatin analogues in the majority of CNFAs. Immunohistochemical profile except for silent corticotroph adenomas is not helpful for predicting receptor expression. qRT-PCR could help to choose patients profiting from expensive medical treatment with somatostatin analogues and chimeric compounds and preventing residuum tumor growth.
Project is supported by Ministry of Health Project No. NT/11344-4/2010 and GAUK 723912
Nothing to Disclose: FG, MD, MB, DN, VM, TC, JM, JC
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