Heterotrimeric G-protein, Gα16, is a critical downstream effector of non-canonical Wnt signaling and a potent inhibitor of transformed cell growth in non small cell lung cancer

PLoS One. 2013 Oct 18;8(10):e76895. doi: 10.1371/journal.pone.0076895. eCollection 2013.

Abstract

G-protein-coupled receptors (GPCR) are the largest family of cell surface molecules that play important role/s in a number of biological and pathological processes including cancers. Earlier studies have highlighted the importance of Wnt7a signaling via its cognate receptor Frizzled9, a GPCR, in inhibition of cell proliferation, anchorage-independent growth, and reversal of transformed phenotype in non small cell lung cancer primarily through activation of the tumor suppressor, PPARγ. However, the G-protein effectors that couple to this important tumor suppressor pathway have not been identified, and are of potential therapeutic interest. In this study, by using two independent Wnt7a/Frizzled9-specific read-outs, we identify Gα16 as a novel downstream effector of Wnt7a/Frizzled9 signaling. Interestingly, Gα16 expression is severely down-regulated, both at the messenger RNA levels and protein levels, in many non small cell lung cancer cell lines. Additionally, through gene-specific knock-downs and expression of GTPase-deficient forms (Q212L) of Gα16, we also establish Gα16 as a novel regulator of non small cell lung cancer cell proliferation and anchorage-independent cell growth. Taken together, our data not only establish the importance of Gα16 as a critical downstream effector of the non-canonical Wnt signaling pathway but also as a potential therapeutic target for the treatment of non small cell lung cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / metabolism
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cell Line
  • Cell Line, Tumor
  • Cell Proliferation*
  • Enzyme Activation
  • Frizzled Receptors / genetics
  • Frizzled Receptors / metabolism
  • GTP-Binding Protein alpha Subunits, Gq-G11 / genetics
  • GTP-Binding Protein alpha Subunits, Gq-G11 / metabolism*
  • Growth Inhibitors / genetics
  • Growth Inhibitors / metabolism*
  • Humans
  • Immunoblotting
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism
  • Lung Neoplasms / pathology
  • Mitogen-Activated Protein Kinase 7 / metabolism
  • Mutation
  • PPAR gamma / metabolism
  • RNA Interference
  • Receptor Tyrosine Kinase-like Orphan Receptors / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Wnt Proteins / genetics
  • Wnt Proteins / metabolism
  • Wnt Signaling Pathway*

Substances

  • FZD9 protein, human
  • Frizzled Receptors
  • Growth Inhibitors
  • PPAR gamma
  • WNT7A protein, human
  • Wnt Proteins
  • ROR1 protein, human
  • ROR2 protein, human
  • Receptor Tyrosine Kinase-like Orphan Receptors
  • Mitogen-Activated Protein Kinase 7
  • G protein alpha 16
  • GTP-Binding Protein alpha Subunits, Gq-G11