Notch1 signaling promotes primary melanoma progression by activating mitogen-activated protein kinase/phosphatidylinositol 3-kinase-Akt pathways and up-regulating N-cadherin expression

Zhao Jun Liu, Min Xiao, Klara Balint, Keiran S.M. Smalley, Patricia Brafford, Ruihua Qiu, Chelsea C. Pinnix, Xueli Li, Meenhard Herlyn

Research output: Contribution to journalArticle

219 Scopus citations


Cellular signaling mediated by Notch receptors results in coordinated regulation of cell growth, survival, and differentiation. Aberrant Notch activation has been linked to a variety of human neoplasms. Here, we show that Notch1 signaling drives the vertical growth phase (VGP) of primary melanoma toward a more aggressive phenotype. Constitutive activation of Notch1 by ectopic expression of the Notch1 intracellular domain enables VGP primary melanoma cell lines to proliferate in a serum-independent and growth factor-independent manner in vitro and to grow more aggressively with metastatic activity in vivo. Notch1 activation also enhances tumor cell survival when cultured as three-dimensional spheroids. Such effects of Notch signaling are mediated by activation of the mitogen-activated protein kinase (MAPK) and Akt pathways. Both pathways are activated in melanoma cells following Notch1 pathway activation. Inhibition of either the MAPK or the phosphatidylinositol 3-kinase (PI3K)-Akt pathway reverses the Notch1 signaling-induced tumor cell growth. Moreover, the growth-promoting effect of Notch1 depends on mastermind-like 1. We further showed that Notch1 activation increases tumor cell adhesion and up-regulates N-cadherin expression. Our data show regulation of MAPK/ PI3K-Akt pathway activities and expression of N-cadherin by the Notch pathway and provide a mechanistic basis for Notch signaling in the promotion of primary melanoma progression.

Original languageEnglish (US)
Pages (from-to)4182-4190
Number of pages9
JournalCancer Research
Issue number8
StatePublished - Apr 15 2006
Externally publishedYes


ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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