PLCA8 suppresses breast cancer apoptosis by activating the PI3k/AKT/NF-κB pathway

J Cell Mol Med. 2019 Oct;23(10):6930-6941. doi: 10.1111/jcmm.14578. Epub 2019 Aug 26.

Abstract

The cysteine-rich lysosomal protein placenta-specific 8 (PLAC8), also called onzin, has been shown to be involved in many types of cancers, and its role is highly dependent on cellular and physiological contexts. However, the precise function of PLAC8 in breast cancer (BC) progression remains unclear. In this study, we investigated both the clinical significance and biological functions of PLAC8 in BC progression. First, high PLAC8 expression was observed in primary BC tissues compared with adjacent normal tissues through immunohistochemistry analysis. The results of in vitro and in vivo assays further confirmed that PLAC8 overexpression promotes cell proliferation and suppress BC cell apoptosis, whereas PLAC8 silencing has the opposite effect. In addition, the forced expression of PLAC8 greatly induces cell migration, partially by affecting the EMT-related genes, including down-regulating E-cadherin expression and facilitating vimentin expression. Further mechanistic analysis confirmed that PLAC8 contributes to cell proliferation and suppresses cell apoptosis in BC by activating the PI3K/AKT/NF-κB pathway. The results of our study provide new insights into an oncogenic role of PLAC8 and reveal a novel PLAC8/ PI3K/AKT/NF-κB pathway as a potential therapeutic target for BC.

Keywords: PLAC8; breast cancer; tumour growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology*
  • Caspases / metabolism
  • Cell Line, Tumor
  • Cell Movement / genetics
  • Cell Proliferation / genetics
  • Cell Survival / genetics
  • Female
  • Gene Expression Regulation, Neoplastic
  • Gene Silencing
  • Humans
  • Mice, Inbred BALB C
  • Mice, Nude
  • Middle Aged
  • NF-kappa B / metabolism*
  • Neoplasm Invasiveness
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Proteins / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Signal Transduction*
  • Up-Regulation / genetics

Substances

  • NF-kappa B
  • PLAC8 protein, human
  • Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Proto-Oncogene Proteins c-akt
  • Caspases