Annexin-A1 controls an ERK-RhoA-NFκB activation loop in breast cancer cells

Pradeep Bist1, Qian Hui Phua1, Shinla Shu1

  • 1Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore; NUS Immunology Program, Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.

Insights

Annexin-A1 (ANXA1) impacts cell migration and wound healing by activating ERK1/2 and RhoA signaling pathways. This activation is crucial for NFκB-mediated processes, particularly in invasive breast cancer.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Cancer Research

Background:

  • Wound healing is essential for development and implicated in cancer metastasis.
  • Mitogen-activated protein kinase (MAPK), Rho-GTPases, and nuclear factor kappa B (NFκB) are key regulators of wound healing.
  • The integration mechanisms of these pathways remain unclear, particularly concerning Annexin-A1 (ANXA1) in invasive breast cancer.

Purpose of the Study:

  • To elucidate the role of Annexin-A1 (ANXA1) in regulating cell migration and wound healing.
  • To investigate the molecular mechanisms integrating ANXA1 with MAPK, RhoA, and NFκB signaling pathways.

Main Methods:

  • Silencing of Annexin-A1 (ANXA1) expression.
  • Analysis of stress fiber and focal adhesion formation.
  • Assessment of ERK1/2 and RhoA activation.
  • Investigation of NFκB activation under various RhoA conditions and stimuli (CXCL12, MEKK plasmids).

Main Results:

  • Silencing ANXA1 increased stress fiber and focal adhesion formation, potentially inhibiting wound healing.
  • ANXA1-regulated wound healing depends on ERK1/2 activation, which in turn activates RhoA.
  • Active RhoA is critical for NFκB activation, potentiating it when constitutively active and inhibiting it with dominant-negative RhoA.

Conclusions:

  • Annexin-A1 (ANXA1) plays a central role in cell migration via the activation of NFκB, ERK1/2, and RhoA signaling.
  • These findings highlight a novel regulatory axis involving ANXA1, ERK1/2, RhoA, and NFκB in processes like cancer metastasis.

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