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
Conclusion
mTORis do not significantly change the immunohistochemical expression of molecules upstream of the mTOR inhibition (pmTOR, PI3K, pAkt), in cutaneous SCC.
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.