Cisplatin increases PD-L1 expression and optimizes immune check-point blockade in non-small cell lung cancer

Cancer Lett. 2019 Nov 1:464:5-14. doi: 10.1016/j.canlet.2019.08.005. Epub 2019 Aug 9.

Abstract

The number of clinical protocols testing combined therapies including immune check-point inhibitors and platinum salts is currently increasing in lung cancer treatment, however preclinical studies and rationale are often lacking. Here, we evaluated the impact of cisplatin treatment on PD-L1 expression analyzing the clinicopathological characteristics of patients who received cisplatin-based neoadjuvant chemotherapy followed by surgery and showed that cisplatin-based induction treatment significantly increased PD-L1 staining in both tumor and immune cells from the microenvironment. Twenty-two patients exhibited positive PD-L1 staining variation after neoadjuvant chemotherapy; including 9 (23.1%) patients switching from <50% to ≥50% of stained tumor-cells. We also confirmed the up-regulation of PD-L1 by cisplatin, at both RNA and protein levels, in nude and immunocompetent mice bearing tumors grafted with A549, LNM-R, or LLC1 lung cancer cell lines. The combined administration of anti-PD-L1 antibodies (3 mg/kg) and cisplatin (1 mg/kg) to mice harboring lung carcinoma significantly reduced tumor growth compared to single agent treatments and controls. Overall, these results suggest that cisplatin treatment could synergize with PD-1/PD-L1 blockade to increase the clinical response, in particular through early and sustainable enhancement of PD-L1 expression.

Keywords: Cisplatin; Immune check-point inhibitors; Lung cancer; Neoadjuvant treatment; PD-L1.

MeSH terms

  • A549 Cells
  • Aged
  • Animals
  • Antineoplastic Agents, Immunological / administration & dosage*
  • Antineoplastic Agents, Immunological / pharmacology
  • B7-H1 Antigen / genetics*
  • B7-H1 Antigen / metabolism*
  • Carcinoma, Non-Small-Cell Lung / drug therapy*
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / metabolism
  • Cell Line, Tumor
  • Cisplatin / administration & dosage*
  • Cisplatin / pharmacology
  • Drug Synergism
  • Female
  • Gene Expression Regulation, Neoplastic / drug effects
  • Humans
  • Immunotherapy
  • Lung Neoplasms / drug therapy*
  • Lung Neoplasms / genetics
  • Lung Neoplasms / metabolism
  • Lymphatic Metastasis
  • Male
  • Mice
  • Middle Aged
  • Neoadjuvant Therapy
  • Up-Regulation / drug effects
  • Xenograft Model Antitumor Assays

Substances

  • Antineoplastic Agents, Immunological
  • B7-H1 Antigen
  • CD274 protein, human
  • Cisplatin