PTEN reconstitution alters glioma responses to c-Met pathway inhibition

C. Rory Goodwin, Bachchu Lal, Sandra Ho, Crystal L. Woodard, Xin Zhou, Alexandra Taeger, Shuli Xia, John Laterra

Research output: Contribution to journalArticle

Abstract

Mutations/deletions of the tumor-suppressor phosphatase and tensin homolog PTEN result in PI3K/Akt pathway hyperactivation and potentially alter oncogenic responses to targeted receptor tyrosine kinase inhibitors. We previously showed that hepatocyte growth factor (HGF):c-Met pathway inhibition decreases tumor growth and oncogenic signaling responses in PTEN-null/Met+ gliomas. Here, we use two tet-on PTENwt-inducible glioma cell lines and xenograft models to examine the influence of PTEN on oncogenic signaling responses to HGF:c-Met pathway inhibitors. Reconstitution of PTEN inhibited Akt by more than 80% and inhibited cell growth by approximately 70-75% in both cell lines in vitro. C-Met inhibition alone inhibited in-vitro cell growth by approximately 80-85% and the magnitude of growth inhibition was not altered by combining PTEN reconstitution with c-Met inhibition. Combining PTEN reconstitution with Met inhibition arrested a higher percentage of cells in G1/G0 phase of the cell cycle when compared with either PTEN reconstitution or c-Met inhibition alone. Both PTEN reconstitution alone and inhibiting autocrine HGF:c-Met signaling alone, using anti-HGF mAb, robustly inhibited the growth of subcutaneous and intracranial glioma xenografts. Combining anti-HGF therapy with PTEN reconstitution did not significantly alter the magnitude of xenograft growth inhibition. Semiquantitative immunohistopathological analyses revealed that the inhibition of glioma xenograft angiogenesis and cell proliferation by anti-HGF mAb was greatest in conjunction with PTEN reconstitution. In contrast, xenograft cell apoptosis was greatest in response to anti-HGF therapy alone and PTEN reconstitution abrogated the apoptotic response to anti-HGF therapy. These results provide new insights into how PTEN modulates glioma responses to the inhibition of HGF:c-Met signaling and possibly other receptor tyrosine kinase pathways.

Original languageEnglish (US)
Pages (from-to)905-912
Number of pages8
JournalAnti-cancer drugs
Volume22
Issue number9
DOIs
StatePublished - Oct 1 2011

Keywords

  • Akt
  • angiogenesis
  • apoptosis
  • hepatocyte growth factor
  • xenograft

ASJC Scopus subject areas

  • Oncology
  • Pharmacology
  • Pharmacology (medical)
  • Cancer Research

Fingerprint Dive into the research topics of 'PTEN reconstitution alters glioma responses to c-Met pathway inhibition'. Together they form a unique fingerprint.

  • Cite this