Targeted silencing of TEM8 suppresses non‑small cell lung cancer tumor growth via the ERK/Bcl‑2 signaling pathway

Mol Med Rep. 2021 Aug;24(2):595. doi: 10.3892/mmr.2021.12234. Epub 2021 Jun 24.

Abstract

Non‑small cell lung cancer (NSCLC) is one of the most common malignancies with high rates of mortality. Although great progress has been made with the development of novel immunotherapies and targeted therapeutic strategies, the 5‑year total survival rate of lung cancer has remained unchanged over the past few decades. Therefore, more effective therapeutics are urgently needed. Tumor endothelial marker 8 (TEM8) is an integrin‑like cell surface transmembrane protein that has been demonstrated to be upregulated in numerous cancer types and previously showed promise for targeted cancer therapy. However, the role of TEM8 in NSCLC remains poorly understood. The present study aimed to investigate the effects of silencing TEM8 on expression and regulation of extracellular signal‑regulated kinase (ERK)1/2 signaling pathways in NSCLC. In the present study, a lentiviral vector that encoded a short hairpin RNA targeting TEM8 was designed and transfected into Xuanwei Lung Cancer (XWLC)‑05 lung cancer cells to silence TEM8 expression. Male BALB/c‑nu/nu mice were then given subcutaneous injections in the right dorsal flank with XWLC‑05 cells. Microvessel density was measured using an anti‑CD34 antibody. The mRNA and protein levels of ERK1/2 and Bcl‑2 in XWLC‑05 cells or xenograft tumor tissues were detected by reverse transcription‑quantitative polymerase chain reaction and western blotting. TEM8 knockdown was found to significantly inhibit tumor growth and conferred an anti‑angiogenic ability in vivo. Furthermore, TEM8 knockdown suppressed the expression of Bcl‑2 mediated by ERK1/2 activity in XWLC‑05 cells or tissues from mice with NSCLC. To conclude, these results suggest that the targeted silencing of TEM8 may serve as an effective method of treating NSCLC.

Keywords: ERK/Bcl‑2 signaling pathway; angiogenesis; non‑small cell lung cancer; tumor endothelial marker 8.

MeSH terms

  • Animals
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cell Line, Tumor
  • Gene Expression Regulation, Neoplastic
  • Gene Knockdown Techniques
  • Gene Silencing
  • Lung / pathology
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / pathology
  • Lung Neoplasms / therapy
  • Mice
  • Mice, Inbred BALB C
  • Microfilament Proteins / genetics*
  • Microfilament Proteins / metabolism*
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*
  • Receptors, Cell Surface / genetics*
  • Receptors, Cell Surface / metabolism*
  • Receptors, Cell Surface / therapeutic use
  • Signal Transduction*
  • Xenograft Model Antitumor Assays

Substances

  • ANTXR1 protein, human
  • Antxr1 protein, mouse
  • Microfilament Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Receptors, Cell Surface
  • Bcl2 protein, mouse
  • Mapk1 protein, mouse
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3

Grants and funding

The present study was supported by the Basic Research Program of Yunnan Province-Joint Project of Kunming Medical University (grant no. 2018FE001-255) and Health Science and Technology Project of Yunnan Province (grant nos. 2017NS174 and 2018NS0049).