Bone morphogenetic protein 2 inhibits hepatocellular carcinoma growth and migration through downregulation of the PI3K/AKT pathway

Tumour Biol. 2014 Jun;35(6):5189-98. doi: 10.1007/s13277-014-1673-y. Epub 2014 Feb 27.

Abstract

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Previous studies have suggested that abnormal expression of BMP-4, BMP-7, and BMP-9 is correlated with tumor progression in HCC, but the role played by BMP-2 in HCC has not yet been reported. To determine the role of BMP-2 in HCC, we first investigated the effect of exogenous BMP-2 on the growth of the cell lines HCC SK-Hep-1, Hep G2, and Hep 3B. Next, we studied the function of BMP-2 in SK-Hep-1 HCC cell line using a recombinant lentivirus vector to deliver BMP-2. We also used siRNA to silence endogenous BMP-2 expression in the HCC Hep 3B cell line. Then, cell growth and migration were assayed in vitro using WST-8, wound-healing, and transwell invasion assays. Cellular apoptosis and cell-cycle distribution were assessed using flow cytometry. We also investigated the effects of BMP-2 overexpression and knockdown on the expression of proliferating cell nuclear antigen (PCNA), matrix metallopeptidase-2 (MMP-2), phosphorylated AKT (p-AKT), phosphoinositide 3-kinase p85α (PI3Kp85α), Bax, Bcl-2, caspase-3, cleaved caspase-3, p21, and cyclin E. As a result, we observed that BMP-2 inhibited the proliferation of HCC cells. Furthermore, HCC cell proliferation and migration were significantly diminished by BMP-2 overexpression, as was indicated by WST-8, would healing, and transwell assays, while knockdown of BMP-2 led to an increase in proliferation and migration of Hep 3B cells. BMP-2 overexpression significantly increased the susceptibility of SK-Hep-1 cells to low-serum-induced apoptosis, while BMP-2 knockdown reduced the susceptibility of Hep 3B cells. Overexpression of BMP-2 induced G1 phase arrest through upregulation of p21. When BMP-2 expression was elevated in SK-Hep-1 cells, the expression of PI3Kp85α, p-AKT, PCNA, and MMP-2 declined. These results suggest that BMP-2 exerts an inhibitory effect on the growth and migration of HCC cells, possibly via a blockade of PI3K/AKT signaling.

MeSH terms

  • Apoptosis
  • Bone Morphogenetic Protein 2 / physiology*
  • Carcinoma, Hepatocellular / pathology*
  • Cell Line, Tumor
  • Cell Movement*
  • Cell Proliferation*
  • Down-Regulation
  • Humans
  • Liver Neoplasms / pathology*
  • Neoplasm Invasiveness
  • Phosphatidylinositol 3-Kinases / physiology*
  • Phosphoinositide-3 Kinase Inhibitors
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors
  • Proto-Oncogene Proteins c-akt / physiology*
  • RNA, Small Interfering / genetics
  • Signal Transduction

Substances

  • Bone Morphogenetic Protein 2
  • Phosphoinositide-3 Kinase Inhibitors
  • RNA, Small Interfering
  • Proto-Oncogene Proteins c-akt