Downregulation of ASPP2 promotes gallbladder cancer metastasis and macrophage recruitment via aPKC-ι/GLI1 pathway

Cell Death Dis. 2018 Nov 2;9(11):1115. doi: 10.1038/s41419-018-1145-1.

Abstract

Gallbladder cancer (GBC) is a highly malignant bile duct cancer with poor prognosis due to early invasion and metastasis. However, the molecular mechanisms through which GBC cells interact with the tumor microenvironment (TME) remain poorly understood. Here, we examined the role of the tumor suppressor apoptosis-stimulating of p53 protein 2 (ASPP2) in regulating GBC invasion and metastasis and macrophage recruitment. The clinicopathological significance of ASPP2 expression was measured by immunohistochemical analysis in 72 patients with GBC. Lentivirus-mediated knockdown or overexpression of ASPP2 was used to investigate the biological functions and molecular mechanisms of ASPP2 in GBC cells. Our data showed that downregulation of ASPP2 in patients with GBC was linked to poor prognosis. Knockdown of ASPP2 induced epithelial-mesenchymal transition (EMT) in GBC cells and influenced the TME. Mechanistically, we further confirmed that ASPP2 affected the expression and protein binding between atypical protein kinase C (aPKC)-ι and glioma-associated oncogene homolog 1 (GLI1). ASPP2 also induced C-C motif chemokine ligand (CCL) 2, CCL5, and tumor necrosis factor-α secretion by cancer cells, thereby promoting macrophage recruitment. The latter also induced EMT-like changes in GBC. Furthermore, ASPP2 deficiency regulated GLI1 transcriptional activity via the noncanonical Hedgehog (Hh) pathway and aPKC-ι/GLI1 signaling loop and promoted GLI1 nuclear localization and binding to the promoters of target genes. Our findings revealed that downregulation of ASPP2 promoted GBC invasion and metastasis through the aPKC-ι/GLI1 pathway and enhanced macrophage recruitment. Thus, ASPP2/aPKC-ι/GLI1 pathway may be a potential therapeutic target for the treatment of GBC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Animals
  • Apoptosis Regulatory Proteins / genetics*
  • Apoptosis Regulatory Proteins / metabolism
  • Bile Duct Neoplasms / diagnosis
  • Bile Duct Neoplasms / genetics*
  • Bile Duct Neoplasms / mortality
  • Bile Duct Neoplasms / surgery
  • Cell Line, Tumor
  • Cell Movement
  • Cell Proliferation
  • Chemokine CCL2 / genetics
  • Chemokine CCL2 / metabolism
  • Chemokine CCL5 / genetics
  • Chemokine CCL5 / metabolism
  • Cholangiocarcinoma / diagnosis
  • Cholangiocarcinoma / genetics*
  • Cholangiocarcinoma / mortality
  • Cholangiocarcinoma / surgery
  • Epithelial-Mesenchymal Transition / genetics
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Heterografts
  • Humans
  • Lymphatic Metastasis
  • Macrophages / metabolism
  • Macrophages / pathology
  • Male
  • Mice
  • Mice, Nude
  • Middle Aged
  • Neoplasm Staging
  • Prognosis
  • Protein Kinase C / genetics*
  • Protein Kinase C / metabolism
  • Signal Transduction
  • Survival Analysis
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism
  • Zinc Finger Protein GLI1 / genetics*
  • Zinc Finger Protein GLI1 / metabolism

Substances

  • Apoptosis Regulatory Proteins
  • CCL2 protein, human
  • CCL5 protein, human
  • Chemokine CCL2
  • Chemokine CCL5
  • GLI1 protein, human
  • TP53BP2 protein, human
  • Tumor Necrosis Factor-alpha
  • Zinc Finger Protein GLI1
  • PKC-3 protein
  • Protein Kinase C