TY - JOUR
T1 - Leptin-R and its association with PI3K/AKT signaling pathway in papillary thyroid carcinoma
AU - Uddin, Shahab
AU - Bavi, Prashant
AU - Siraj, Abdul K.
AU - Ahmed, Maqbool
AU - Al-Rasheed, Maha
AU - Hussain, Azhar R.
AU - Ahmed, Mohammed
AU - Amin, Tarek
AU - Alzahrani, Ali
AU - Al-Dayel, Fouad
AU - Abubaker, Jehad
AU - Bu, Rong
AU - Al-Kuraya, Khawla S.
PY - 2010/3/1
Y1 - 2010/3/1
N2 - The putative role of leptin and its receptor (Ob-R) in the pathogenesis of various primary human malignancies has been reported; however, their role in papillary thyroid cancer (PTC) has not yet been evaluated. We investigated the role of Ob-R in a large tissue microarray cohort of PTC followed by in vitro studies using a panel of PTC cell lines. Ob-R overexpression was seen in 80% PTCs and was significantly associated with poor disease-free survival (P=0.0235). PTCs that overexpressed Ob-R showed a aggressive phenotype characterized by older age, extrathyroid extension, larger tumor size, nodal metastasis, advanced stage, tall cell variant histological subtype, and a poor disease-free survival (P=0.0005, P=0.0006, P=0.0398, P=0.0004, P=0.0111, P=0.0003, and P=0.0235 respectively). However, Ob-R expression was not an independent prognostic marker to predict disease-free survival in multivariate analysis. PTCs with overexpression of Ob-R showed a significant direct association with overexpression of XIAP (P<0.0001) and Bcl-XL (P<0.0001). In vitro analysis showed that leptin stimulated cell proliferation and inhibited apoptosis via activation of phosphatidylinisitol 3′ kinase (PI3K)/protein kinase B (AKT) signaling pathway. Inhibition of PI3K activity by its inhibitor LY294002 abrogated leptin-mediated PI3K/AKT signaling. Gene silencing of Ob-R in PTC cells resulted in downregulation of phospho-AKT, Bcl-XL, and XIAP expression suggesting that leptin-mediated pathogenesis of PTC occurs via involvement of these downstream targets. Altogether, these data show that leptin plays an important role in PTC pathogenesis through PI3K/AKT pathway via Ob-R and is a potential prognostic marker associated with an aggressive phenotype and poor disease-free survival.
AB - The putative role of leptin and its receptor (Ob-R) in the pathogenesis of various primary human malignancies has been reported; however, their role in papillary thyroid cancer (PTC) has not yet been evaluated. We investigated the role of Ob-R in a large tissue microarray cohort of PTC followed by in vitro studies using a panel of PTC cell lines. Ob-R overexpression was seen in 80% PTCs and was significantly associated with poor disease-free survival (P=0.0235). PTCs that overexpressed Ob-R showed a aggressive phenotype characterized by older age, extrathyroid extension, larger tumor size, nodal metastasis, advanced stage, tall cell variant histological subtype, and a poor disease-free survival (P=0.0005, P=0.0006, P=0.0398, P=0.0004, P=0.0111, P=0.0003, and P=0.0235 respectively). However, Ob-R expression was not an independent prognostic marker to predict disease-free survival in multivariate analysis. PTCs with overexpression of Ob-R showed a significant direct association with overexpression of XIAP (P<0.0001) and Bcl-XL (P<0.0001). In vitro analysis showed that leptin stimulated cell proliferation and inhibited apoptosis via activation of phosphatidylinisitol 3′ kinase (PI3K)/protein kinase B (AKT) signaling pathway. Inhibition of PI3K activity by its inhibitor LY294002 abrogated leptin-mediated PI3K/AKT signaling. Gene silencing of Ob-R in PTC cells resulted in downregulation of phospho-AKT, Bcl-XL, and XIAP expression suggesting that leptin-mediated pathogenesis of PTC occurs via involvement of these downstream targets. Altogether, these data show that leptin plays an important role in PTC pathogenesis through PI3K/AKT pathway via Ob-R and is a potential prognostic marker associated with an aggressive phenotype and poor disease-free survival.
UR - http://www.scopus.com/inward/record.url?scp=77449155450&partnerID=8YFLogxK
U2 - 10.1677/ERC-09-0153
DO - 10.1677/ERC-09-0153
M3 - Article
C2 - 20008098
AN - SCOPUS:77449155450
VL - 17
SP - 191
EP - 202
JO - Endocrine-Related Cancer
JF - Endocrine-Related Cancer
SN - 1351-0088
IS - 1
ER -