Poster Presentation Advances in Neuroblastoma Research Congress 2016

GOLPH3 regulates Golgi shape and is activated by DNA damage in neuroblastoma cell lines (#366)

Annalisa Pezzolo 1 , Gabriella Pagnan 1 , Angela R Sementa 2 , Martina Morini 3 , Davide Cangelosi 3 , Luigi Varesio 3 , Alberto Garaventa 4 , Vito Pistoia 1
  1. 1 LABORATORY OF ONCOLOGY , GIANNINA GASLINI INSTITUTE, GENOVA, ITALY
  2. 2 LABORATORY OF PATHOLOGY, GIANNINA GASLINI INSTITUTE, GENOVA, ITALY
  3. 3 LABORATORY OF MOLECULAR BIOLOGY, GIANNINA GASLINI INSTITUTE, GENOVA, ITALY
  4. 4 DEPARTMENT OF HEMATOLOGY ONCOLOGY, GIANNINA GASLINI INSTITUTE, GENOVA, ITALY

Background: Golgi phosphoprotein 3 (GOLPH3) has been reported to be involved in the development of several human cancers. The over-expression of GOLPH3 promotes cell transformation by enhancing the activity of the serine/threonine kinase mTOR. The clinical significance and biological role of GOLPH3 in neuroblastoma (NB) remains unclear. GOLPH3 is a membrane protein that binds to Myosin-XVIIIA (MYO18A) protein linking the Golgi to the actin cytoskeleton. The GOLPH3 pathway is essential for vesicular trafficking from the Golgi to the plasma membrane. A side effect of GOLPH3-dependent trafficking is to generate the extended ribbon shape of the Golgi. Perturbation of the pathway results in changes to both Golgi morphology and secretion, with functional consequences for the cell. Golgi dispersal is a common feature of DNA damage response in mammalian cells. Understanding the cellular response to DNA damage is crucial for discerning the mechanisms by which many chemotherapeutic agents kill tumor cells and the mechanisms of escape from killing.

Methods: We examined whether DNA damage affects Golgi morphology, and the role of GOLPH3 in maintaining Golgi shape in NB cells. We induced DNA damage in the human NB cell lines ACN and SH-SY-5Y with curcumin (10 μM). To investigate the relationship between GOLPH3 expression and DNA damage after treatment with curcumin, GOLPH3 and γH2AX expression were examined by immunofluorescence staining.

Results: Exposure of NB cells to curcumin induced: i) up-regulation of GOLPH3+ cells (80.4±3.22% vs 30.2± 6.18%, p= 0.0001); ii) augmentation of double-strand breaks (γH2AX+ cells 60.9±3.22% vs 25.7± 6.18%, p= 0.0001); iii) fragmentation and dispersal of the Golgi throughout the cytoplasm.

Conclusion: Our findings suggest that GOLPH3 expression levels may represent a clinical marker of NB patient responsiveness to DNA-damaging cancer therapies. Furthermore, novel agents able to interfere with the GOLPH3 pathway may have therapeutic benefit when used in combination with standard DNA-damaging therapeutic agents in NB.