The Role of Serine Protease 8 in Mediating Gefitinib Resistance in Non-small Cell Lung Cancer

Anticancer Agents Med Chem. 2024;24(18):1339-1346. doi: 10.2174/0118715206296807240717165200.

Abstract

Objective: This investigation aims to explore the expression levels of serine protease 8 (PRSS8) in gefitinib-resistant Non-Small Cell Lung Cancer (NSCLC) cell lines (PC9/GR) and elucidate its mechanism of action.

Methods: We measured PRSS8 expression in gefitinib-resistant (PC9/GR) and sensitive (PC9) NSCLC cell lines using Western blot analysis. PRSS8-specific small interfering RNA (PRSS8-siRNA), a recombinant plasmid, and a corresponding blank control were transfected into PC9/GR cells. Subsequently, Western blot analyses were conducted to assess the expression levels of PRSS8, phosphorylated AKT (p-AKT), AKT, phosphorylated mTOR (p-mTOR), mTOR, and various apoptosis-related proteins within each group. Additionally, a cell proliferation assay utilizing Cell Counting Kit-8 (CCK8) was performed on each group treated with gefitinib.

Results: PRSS8 expression was markedly higher in PC9/GR cells compared to PC9 cells (p < 0.05). The group treated with PRSS8-siRNA exhibited significantly reduced protein expression levels of PRSS8, p-AKT, p-mTOR, β-catenin, and BCL-2 compared to the control siRNA (Con-siRNA) group, whereas expressions of Caspase9 and Bax were significantly increased. In the untransfected PC9/GR cells, protein expressions of PRSS8, p-AKT, pmTOR, and BCL-2 were significantly elevated when compared with the plasmid-transfected group, which also showed a significant reduction in Bax expression. The proliferative activity of the PRSS8-siRNA group postgefitinib treatment was significantly diminished at 24, 48, and 72 hours in comparison to the Con-siRNA group.

Conclusion: The findings indicate that PRSS8 contributes to the acquisition of resistance to gefitinib in NSCLC, potentially through regulation of the AKT/mTOR signaling pathway.

Keywords: AKT/mTOR signaling pathway.; Gefitinib resistance; PC9/GR cells; cell proliferation; non-small cell lung cancer; serine protease 8.

MeSH terms

  • Antineoplastic Agents* / chemistry
  • Antineoplastic Agents* / pharmacology
  • Apoptosis / drug effects
  • Carcinoma, Non-Small-Cell Lung* / drug therapy
  • Carcinoma, Non-Small-Cell Lung* / metabolism
  • Carcinoma, Non-Small-Cell Lung* / pathology
  • Cell Proliferation* / drug effects
  • Dose-Response Relationship, Drug
  • Drug Resistance, Neoplasm* / drug effects
  • Drug Screening Assays, Antitumor
  • Gefitinib* / pharmacology
  • Humans
  • Lung Neoplasms* / drug therapy
  • Lung Neoplasms* / metabolism
  • Lung Neoplasms* / pathology
  • Molecular Structure
  • Structure-Activity Relationship
  • Tumor Cells, Cultured

Substances

  • Gefitinib
  • Antineoplastic Agents