Proteasome inhibition by bortezomib parallels a reduction in head and neck cancer cells growth, and an increase in tumor-infiltrating immune cells

Monica Benvenuto,Massimo Coletta,Maria Segni,Sara Ciuffa,Andrea Modesti,Roberto Bei,Giovanni Barillari,Chiara Focaccetti,Vittorio Manzari,Diego Sbardella,Laura Masuelli,Grazia Raffaella Tundo,Sara Fazi,Elena Bonanno,Manuel Scimeca

doi:10.1038/s41598-021-98450-6

Abstract

Head and neck cancer (HNC) has frequently an aggressive course for the development of resistance to standard chemotherapy. Thus, the use of innovative therapeutic drugs is being assessed. Bortezomib is a proteasome inhibitor with anticancer effects. In vitro antitumoral activity of Bortezomib was investigated employing human tongue (SCC-15, CAL-27), pharynx (FaDu), salivary gland (A-253) cancer cell lines and a murine cell line (SALTO-5) originated from a salivary gland adenocarcinoma arising in BALB-neuT male mice transgenic for the oncogene neu. Bortezomib inhibited cell proliferation, triggered apoptosis, modulated the expression and activation of pro-survival signaling transduction pathways proteins activated by ErbB receptors and inhibited proteasome activity in vitro. Intraperitoneal administration of Bortezomib delayed tumor growth of SALTO-5 cells transplanted in BALB-neuT mice, protracted mice survival and adjusted tumor microenvironment by increasing tumor-infiltrating immune cells (CD4+ and CD8+ T cells, B lymphocytes, macrophages, and Natural Killer cells) and by decreasing vessels density. In addition, Bortezomib modified the expression of proteasome structural subunits in transplanted SALTO-5 cells. Our findings further support the use of Bortezomib for the treatment of HNC and reveal its ineffectiveness in counteracting the activation of deregulated specific signaling pathways in HNC cell lines when resistance to proteasome inhibition is developed.

Highlights

Head and neck cancer (HNC) has frequently an aggressive course for the development of resistance to standard chemotherapy
The survival of tongue (SCC-15, CAL-27), pharynx (FaDu), and salivary gland (A-253) cancer cells was evaluated by the Sulforhodamine B (SRB) assay after exposure to increasing doses of Bortezomib (6.25–12.5–25–50–100 nM) or vehicle control (DMSO) for 24, 48 and 72 h
Our results showed that Bortezomib significantly increased Beclin-1 expression in SCC-15 (p = 0.0007) and A-253 (p = 0.0015) cells, while it was decreased in CAL-27 (p = 0.0005), FaDu (p = 0.011) and SALTO-5 (p = 0.0021) cells (Fig. 5)

Summary

Introduction

Head and neck cancer (HNC) has frequently an aggressive course for the development of resistance to standard chemotherapy. Our findings further support the use of Bortezomib for the treatment of HNC and reveal its ineffectiveness in counteracting the activation of deregulated specific signaling pathways in HNC cell lines when resistance to proteasome inhibition is developed. Inhibitors of the Ubiquitin Proteasome System (UPS), and in particular of the proteasome, are assuming particular importance[13] They have become a new relevant class of drugs for treatment of tumors, regulation of the immune response and as anti-inflammatory agents[14,15]. Some of them has already entered clinical trials in solid malignancies providing outstanding outcomes in terms of overall survival (OS)[15] In this framework, the clinical success of Bortezomib in treatment of haematological disorders, in particular multiple myeloma, has pioneristically validated the relevance of this therapeutic strategy. Several clinical trials evaluated the effect of Bortezomib in combination with chemotherapy or other targeted therapies in H NC27–34

Objectives

Methods

Results

Conclusion