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mTOR Signalling Pathway-protein Expression in Post-transplant Cutaneous Squamous-cell Carcinomas Before and After

Triantafyllia Koletsa1, Georgios Petrakis1, Georgia Karayannopoulou1

  • 1Department of Pathology, AHEPA Hospital, Aristotelian University of Thessaloniki, Thessaloniki, Greece.

Anticancer Research
|June 1, 2018
PubMed
Abstract

Insights

Mammalian target of rapamycin inhibitors (mTORis) do not significantly alter key protein expression in cutaneous squamous cell carcinomas (SCC) of organ-transplant recipients. This suggests mTORis do not impact the mTOR pathway in these skin tumors.

Area of Science:

  • Oncology
  • Immunology
  • Dermatology

Background:

  • Mammalian target of rapamycin inhibitors (mTORis) are used in organ-transplant recipients (OTR) for immunosuppression and to reduce skin tumor burden.
  • Cutaneous squamous cell carcinoma (SCC) is a common concern in OTR.
  • The effects of mTORis on SCC tumor biology in OTR require further investigation.

Purpose of the Study:

  • To investigate the impact of mTOR inhibitors on the expression of key mTOR pathway proteins in cutaneous squamous cell carcinomas (SCC) from organ-transplant recipients (OTR).
  • To compare the expression levels of pAkt, pmTOR, and PI3K in SCCs before and after switching to mTOR inhibitors.

Main Methods:

  • Immunohistochemical analysis was performed on 23 SCC tissue sections from OTR.
  • Antibodies targeting pAkt, pmTOR, and PI3K were used to assess protein expression.
  • SCC samples were analyzed both before and after the patients were switched to mTOR inhibitors.

Main Results:

  • Phosphorylated mTOR (pmTOR) expression was observed in a similar proportion of SCCs before (8/12) and after (8/11) switching to mTORis.
  • Phosphatidylinositol 3-kinase (PI3K) was expressed in most SCCs (21/23), and pAkt was universally expressed in all SCCs.
  • No significant changes in the immunohistochemical expression of pmTOR, PI3K, or pAkt were detected after switching to mTORis.

Conclusions:

  • mTOR inhibitors do not significantly alter the expression of pmTOR, PI3K, or pAkt in cutaneous SCCs from OTR.
  • The study suggests that the upstream components of the mTOR pathway in these skin tumors remain largely unchanged despite mTOR inhibition.
  • Further research may be needed to fully elucidate the mechanisms of action of mTORis in preventing skin tumors in OTR.
Keywords:
PI3KimmunohistochemistrymTOR signalingorgan transplant recipientspAktpmTORskinsquamous-cell carcinoma

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