RT Journal Article
SR Electronic
T1 mTOR–RAPTOR and 14-3-3σ immunohistochemical expression in high grade prostatic intraepithelial neoplasia and prostatic adenocarcinomas: a tissue microarray study
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 683
OP 688
DO 10.1136/jclinpath-2011-200083
VO 64
IS 8
A1 Evren, Sevan
A1 Dermen, Arthur
A1 Lockwood, Gina
A1 Fleshner, Neil
A1 Sweet, Joan
YR 2011
UL http://jcp.bmj.com/content/64/8/683.abstract
AB Background The mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase which associates with regulatory-associated protein of TOR (RAPTOR), forming the mTORC1 complex, which is necessary for activation of the mTOR pathway. 14-3-3σ belongs to a family of proteins known to regulate the mTOR–RAPTOR interaction and signalling of this cascade. The mTOR pathway is a key regulator of protein synthesis and growth and is up-regulated in many cancers. The correlation of mTOR, RAPTOR and 14-3-3σ in high grade prostatic intraepithelial neoplasia (HGPIN) and prostate cancer has not previously been investigated.Aims To examine the immunohistochemical expression of phosphorylated mTOR (p-mTOR), RAPTOR and 14-3-3σ in HGPIN and prostatic adenocarcinoma (PCa) using tissue microarrays.Methods and results There were contrasting immunohistochemical patterns of expression for mTOR and 14-3-3σ in HGPIN and PCa. Cochran–Armitage analysis demonstrated decreasing p-mTOR and increasing 14-3-3σ expression, progressing from PIN through GL6 and GL7 to high grade PCa. In cores with coexistent staining for 14-3-3σ and p-mTOR, the expression of each marker was restricted to different geographical areas of an individual core.Conclusion The inverse correlation of p-mTOR and 14-3-3σ expression supports the role of 14-3-3σ as an inhibitor of p-mTOR activity in the prostate. The extent of 14-3-3σ and mTOR expression in an individual patient with prostate cancer would determine how effective the use of mTOR inhibitors would be as potential therapeutic agents.