RUVBL1-ITFG1 interaction is required for collective invasion in breast cancer

Biochim Biophys Acta Gen Subj. 2017 Jul;1861(7):1788-1800. doi: 10.1016/j.bbagen.2017.03.016. Epub 2017 Mar 21.

Abstract

Background: The mechanisms of breast cancer collective invasion are poorly understood limiting the metastasis therapy. The ATPase RUVBL1 is frequently overexpressed in various cancers and plays a crucial role in oncogenic process. We further investigated the role of RUVBL1 in promoting collective invasion and uncovered that targeting RUVBL1 could inhibit metastatic progression.

Methods: The expression levels of RUVBL1 and ITFG1 were examined by Western blot and qRT-PCR. Co-localization and interaction of RUVBL1 and ITFG1 were determined by immunofluorescence and co-immunoprecipitation. The invasive ability was examined by transwell assay and microfluidic assay. The metastatic and tumorigenic abilities of breast cancer cells were revealed in BALB/c nude mice by xenograft and tail vein injection.

Results: ATPase RUVBL1 is highly expressed in breast cancer and predicts the poor prognosis. Elevated expression of RUVBL1 is found in high metastatic breast cancer cells. Silencing RUVBL1 suppresses cancer cell expansion and invasion in vitro and in vivo. RUVBL1 interacts with a conserved transmembrane protein ITFG1 in cytoplasm and plasma membrane to promote the collective invasion. Using a microfluidic model, we demonstrated that silencing RUVBL1 or ITFG1 individually compromises collective invasion of breast cancer cells.

Conclusion: RUVBL1 is a vital regulator for collective invasion. The interaction between RUVBL1 and ITFG1 is required for breast cancer cell collective invasion and progression.

General significance: Targeting collective invasion promoted by RUVBL1-ITFG1 complex provides a novel therapeutic strategy to improve the prognosis of invasive breast cancer.

Keywords: Breast cancer; Collective invasion; ITFG1; Microfluidic; RUVBL1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATPases Associated with Diverse Cellular Activities
  • Animals
  • Breast Neoplasms / pathology*
  • Carrier Proteins / analysis
  • Carrier Proteins / physiology*
  • Cell Line, Tumor
  • DNA Helicases / analysis
  • DNA Helicases / physiology*
  • Epithelial-Mesenchymal Transition
  • Female
  • Humans
  • Membrane Proteins / analysis
  • Membrane Proteins / physiology*
  • Mice
  • Mice, Inbred BALB C
  • Neoplasm Invasiveness
  • Neoplasm Metastasis
  • Protein Binding

Substances

  • Carrier Proteins
  • ITFG1 protein, human
  • Membrane Proteins
  • ATPases Associated with Diverse Cellular Activities
  • DNA Helicases
  • RUVBL1 protein, human