mTOR Signalling Pathway-protein Expression in Post-transplant Cutaneous Squamous-cell Carcinomas Before and After Conversion to mTOR-inhibitors.
BACKGROUND/AIM
Inhibitors of the mammalian target of rapamycin (mTORis) exert immunosuppressive and antitumor effects and are used in organ-transplant recipients (OTR) as immunosuppressants able to reduce skin tumor burden. This study investigated the effects of mTORis on the expression of mTOR pathway proteins in cutaneous squamous-cell carcinomas (SCC) developing in OTR, before and after switching to mTORis.


MATERIALS AND METHODS
An immunohistochemical study was performed on 23 SCC sections excised from OTR with post-transplant SCC, before or after switch to mTORis, with antibodies against pAkt, pmTOR and PI3K.


RESULTS
pmTOR expression was found in 8/12 SCC pre-switch, and in 8/11 SCC post-switch, to mTORis. All (but 2) SCC expressed PI3K, and all SCCs expressed pAkt.


CONCLUSION
mTORis do not significantly change the immunohistochemical expression of molecules upstream of the mTOR inhibition (pmTOR, PI3K, pAkt), in cutaneous SCC.
['Koletsa|Triantafyllia|T|', 'Petrakis|Georgios|G|', 'Karayannopoulou|Georgia|G|', 'Euvrard|Sylvie|S|', 'Kanitakis|Jean|J|']
D002294:Carcinoma, Squamous Cell D006801:Humans D007150:Immunohistochemistry D007166:Immunosuppressive Agents D019869:Phosphatidylinositol 3-Kinases D051057:Proto-Oncogene Proteins c-akt D015398:Signal Transduction D020123:Sirolimus D012878:Skin Neoplasms D058570:TOR Serine-Threonine Kinases D013997:Time Factors D014180:Transplantation
mTOR signaling squamous-cell carcinoma skin pAkt pmTOR PI3K immunohistochemistry organ transplant recipients