Increased activation of PI3K/AKT signaling pathway is associated with cholangiocarcinoma metastasis and PI3K/mTOR inhibition presents a possible therapeutic strategy

Supak Yothaisong, Hasaya Dokduang, Anchalee Techasen, Nisana Namwat, Puangrat Yongvanit, Vajarabhongsa Bhudhisawasdi, Anucha Puapairoj, Gregory J. Riggins, Watcharin Loilome

Research output: Contribution to journalArticlepeer-review

Abstract

Phosphatidylinositol 3-kinase (PI3K) signaling plays a critical role in cholangiocarcinoma (CCA), as well as anti-cancer drug resistance and autophagy, the type II program cell death regulation. In this work, we aimed to: (1) determine the expression levels of several key components of PI3K signaling and (2) evaluate whether NVP-BEZ235, a novel dual PI3K/mTOR inhibitor, could inhibit CCA cell growth. Immunohistochemistry for p85α, p110α, AKT, p-AKT (T308), mTOR, p-mTOR (S2448), GSK-3β, p-GSK-3β (S9), PTEN, and p-PTEN (S380, T382/383) was performed in 30 CCA patients. Western blotting was used to analyze PTEN and p-PTEN expression in the cell lines (KKU-OCA17, KKU-100, KKU-M055, KKU-M139, KKU-M156, KKU-M213, and KKU-M214). The effects of NVP-BEZ235 on CCA cells were evaluated using a growth inhibition assay, flow cytometer and migration assay. Increased activation of PI3K/AKT signaling was reproducibly observed in the CCA tissues. The expression of p85α, mTOR, and GSK-3β was significantly correlated with metastasis. Interestingly, PTEN suppression by loss of expression or inactivation by phosphorylation was observed in the majority of patients. Furthermore, NVP-BEZ235 effectively inhibited CCA cell growth and migration through reduced AKT and mTOR phosphorylation and significantly induced G1 arrest without apoptosis induction, although increase autophagy response was observed. In conclusion, the constitutive activation of PI3K/AKT pathway in CCA is mainly due to PTEN inactivation by either loss of expression or phosphorylation along with an increased expression in its pathway components heralding a poor prognosis for CCA patients. This work also indicates that inhibition of PI3K and mTOR activity by the inhibitor NVP-BEZ235 has anti-cancer activity against CCA cells which might be further tested for CCA treatment.

Original languageEnglish (US)
Pages (from-to)3637-3648
Number of pages12
JournalTumor Biology
Volume34
Issue number6
DOIs
StatePublished - Dec 1 2013

Keywords

  • Cholangiocarcinoma
  • NVP-BEZ325
  • PI3K/AKT
  • PTEN
  • mTOR

ASJC Scopus subject areas

  • Cancer Research

Fingerprint Dive into the research topics of 'Increased activation of PI3K/AKT signaling pathway is associated with cholangiocarcinoma metastasis and PI3K/mTOR inhibition presents a possible therapeutic strategy'. Together they form a unique fingerprint.

Cite this