TY - JOUR
T1 - Dysregulation of mammalian target of rapamycin pathway in upper tract urothelial carcinoma
AU - Munari, Enrico
AU - Fujita, Kazutoshi
AU - Faraj, Sheila
AU - Chaux, Alcides
AU - Gonzalez-Roibon, Nilda
AU - Hicks, Jessica
AU - Meeker, Alan
AU - Nonomura, Norio
AU - Netto, George J.
PY - 2013/12
Y1 - 2013/12
N2 - Upper tract urothelial carcinoma (UTUC) accounts for 5% to 10% of all urothelial carcinomas. Despite many shared features, key clinical and molecular genetic differences between upper tract and bladder urothelial carcinomas are becoming apparent. We have previously demonstrated alterations of mammalian target of rapamycin (mTOR) pathway in bladder carcinoma with a potential impact on biological behavior. In the current study, we evaluated the expression status and prognostic significance of mTOR pathway members in UTUC. Archival formalin-fixed and paraffin-embedded tissues from 99 primary UTUCs were retrieved from one of the authors' institution. Tissue microarrays were constructed with triplicate tumor samples and paired nonneoplastic urothelium. Tissue microarrays were analyzed using immunohistochemistry for mTOR pathway members: PTEN, phos-AKT, phos-mTOR, phos-S6, phos-4EBP1, and related markers p27 and c-MYC; correlation with clinicopathologic parameters and outcome was performed. We found significantly lower expression of PTEN, phos-AKT, phos-mTOR, phos-S6, phos-4EBP1, p27, and c-MYC in UTUC compared with paired benign urothelium (P <.0005). We found a strong positive correlation between PTEN and phos-AKT. Moderate correlation was observed between phos-mTOR and phos-S6, PTEN and p27, phos-AKT and p27, phos-S6 and p27, phos-mTOR and c-MYC, phos-S6 and c-MYC, and p27 and c-MYC. None of the evaluated biomarkers were associated with increased hazard ratios for tumor recurrence or for cancer-specific mortality, when adjusting for relevant clinicopathologic variables. Dysregulation of the mTOR pathway was observed in UTUC compared with normal urothelium, implicating a potential pathogenic role in tumor development. In our cohort, expression of the evaluated biomarkers had no prognostic value.
AB - Upper tract urothelial carcinoma (UTUC) accounts for 5% to 10% of all urothelial carcinomas. Despite many shared features, key clinical and molecular genetic differences between upper tract and bladder urothelial carcinomas are becoming apparent. We have previously demonstrated alterations of mammalian target of rapamycin (mTOR) pathway in bladder carcinoma with a potential impact on biological behavior. In the current study, we evaluated the expression status and prognostic significance of mTOR pathway members in UTUC. Archival formalin-fixed and paraffin-embedded tissues from 99 primary UTUCs were retrieved from one of the authors' institution. Tissue microarrays were constructed with triplicate tumor samples and paired nonneoplastic urothelium. Tissue microarrays were analyzed using immunohistochemistry for mTOR pathway members: PTEN, phos-AKT, phos-mTOR, phos-S6, phos-4EBP1, and related markers p27 and c-MYC; correlation with clinicopathologic parameters and outcome was performed. We found significantly lower expression of PTEN, phos-AKT, phos-mTOR, phos-S6, phos-4EBP1, p27, and c-MYC in UTUC compared with paired benign urothelium (P <.0005). We found a strong positive correlation between PTEN and phos-AKT. Moderate correlation was observed between phos-mTOR and phos-S6, PTEN and p27, phos-AKT and p27, phos-S6 and p27, phos-mTOR and c-MYC, phos-S6 and c-MYC, and p27 and c-MYC. None of the evaluated biomarkers were associated with increased hazard ratios for tumor recurrence or for cancer-specific mortality, when adjusting for relevant clinicopathologic variables. Dysregulation of the mTOR pathway was observed in UTUC compared with normal urothelium, implicating a potential pathogenic role in tumor development. In our cohort, expression of the evaluated biomarkers had no prognostic value.
KW - Mammalian target of rapamycin
KW - Prognosis
KW - Upper tract
KW - Urothelial carcinoma
KW - mTOR pathway
UR - http://www.scopus.com/inward/record.url?scp=84888036240&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84888036240&partnerID=8YFLogxK
U2 - 10.1016/j.humpath.2013.07.008
DO - 10.1016/j.humpath.2013.07.008
M3 - Article
C2 - 24074531
AN - SCOPUS:84888036240
VL - 44
SP - 2668
EP - 2676
JO - Human Pathology
JF - Human Pathology
SN - 0046-8177
IS - 12
ER -