Knockdown of REGγ inhibits the proliferation and migration and promotes the apoptosis of multiple myeloma cells by downregulating NF-κB signal pathway

Hematology. 2018 Jun;23(5):277-283. doi: 10.1080/10245332.2017.1385194. Epub 2017 Oct 11.


Objectives: This study aimed to evaluate the effects of REGγ knockdown on the proliferation, apoptosis and migration of multiple myeloma (MM) cells, and reveal the potential regulatory mechanisms.

Methods: The expression of REGγ on myeloma cells of 28 MM patients was detected by Western blot. shRNA-REGγ-1 and shRNA-REGγ-2 were constructed to downregulate REGγ in RPMI-8226 cells. The proliferation, apoptosis and migration of transfected cells were analyzed by Cell Counting Kit 8 (CCK8), flow cytometry and transwell chamber, respectively. The expression of phosphorylated p65 (p-p65), p65, NF-kappa-B inhibitor ε (IkBε), matrix metalloproteinase 2 (MMP2), B-cell lymphoma xL (Bcl-xL) and X-linked inhibitor of apoptosis protein (XIAP) in transfected cells was detected by Western blot. Using cycloheximide (CHX), the half-life period of IkBε was detected by Western blot.

Results: The expression of REGγ was positive in myeloma cells. The proliferation and migration of RPMI-8226 cells were significantly inhibited by shRNA-REGγ-1/shRNA-REGγ-2, while the apoptosis rates were significantly increased (p < 0.05). The expression of p-p65 and IkBε was significantly reduced in RPMI-8226 cells transfected with shRNA-REGγ-1/shRNA-REGγ-2. The degradation of IkBε was significantly lower in RPMI-8226 cells transfected with shRNA-REGγ-1 than the control (longer half-life period). Besides, the expression of MMP2, Bcl-xL and XIAP in RPMI-8226 cells was significantly inhibited by shRNA-REGγ-1/shRNA-REGγ-2.

Discussion: Knockdown of REGγ may inhibit the proliferation and migration, and promote the apoptosis of RPMI-8226 cells possibly by downregulating NF-κB signal pathway.

Keywords: NF-κB; REGγ; apoptosis; migration; multiple myeloma.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Apoptosis / genetics*
  • Autoantigens / genetics*
  • Autoantigens / metabolism
  • Cell Line, Tumor
  • Cell Movement / genetics*
  • Cell Proliferation / genetics*
  • Down-Regulation
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Male
  • Middle Aged
  • Multiple Myeloma / genetics
  • Multiple Myeloma / metabolism
  • Multiple Myeloma / pathology
  • NF-kappa B / metabolism*
  • Proteasome Endopeptidase Complex / genetics*
  • Proteasome Endopeptidase Complex / metabolism
  • RNA Interference
  • Signal Transduction*
  • Young Adult


  • Autoantigens
  • Ki antigen
  • NF-kappa B
  • Proteasome Endopeptidase Complex