Journal Article

Antitumoral effects of Bortezomib in malignant mesothelioma: evidence of mild endoplasmic reticulum stress in vitro and activation of T cell response in vivo

Benvenuto, Monica, Angiolini, Valentina, Barillari, Giovanni, Palumbo, Camilla, Cirone, Mara, Masuelli, Laura, Rufini, Alessandra, Ferretti, Elisabetta, Nardozi, Daniela, Miele, Martino Tony, Focaccetti, Chiara, Bei, Riccardo, Mutti, Luciano, Mancini, Patrizia, Carrano, Raffaele, Tundo, Grazia Raffaella, Bei, Roberto

2023

Overview

Background Malignant mesothelioma (MM) is a rare tumor with a dismal prognosis. The low efficacy of current treatment options highlights the urge to identify more effective therapies aimed at improving MM patients’ survival. Bortezomib (Bor) is a specific and reversible inhibitor of the chymotrypsin-like activity of the 20S core of the proteasome, currently approved for the treatment of multiple myeloma and mantle cell lymphoma. On the other hand, Bor appears to have limited clinical effects on solid tumors, because of its low penetration and accumulation into tumor tissues following intravenous administration. These limitations could be overcome in MM through intracavitary delivery, with the advantage of increasing local drug concentration and decreasing systemic toxicity. Methods In this study, we investigated the effects of Bor on cell survival, cell cycle distribution and modulation of apoptotic and pro-survival pathways in human MM cell lines of different histotypes cultured in vitro. Further, using a mouse MM cell line that reproducibly forms ascites when intraperitoneally injected in syngeneic C57BL/6 mice, we investigated the effects of intraperitoneal Bor administration in vivo on both tumor growth and the modulation of the tumor immune microenvironment. Results We demonstrate that Bor inhibited MM cell growth and induced apoptosis. Further, Bor activated the Unfolded Protein Response, which however appeared to participate in lowering cells’ sensitivity to the drug’s cytotoxic effects. Bor also affected the expression of EGFR and ErbB2 and the activation of downstream pro-survival signaling effectors, including ERK1/2 and AKT. In vivo, Bor was able to suppress MM growth and extend mice survival. The Bor-mediated delay of tumor progression was sustained by increased activation of T lymphocytes recruited to the tumor microenvironment. Conclusions The results presented herein support the use of Bor in MM and advocate future studies aimed at defining the therapeutic potential of Bor and Bor-based combination regimens for this treatment-resistant, aggressive tumor.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Adult / AKT protein / Analysis / Animals / Anticancer properties / Apoptosis / Ascites / Bioaccumulation / Biocompatibility / Biomedical and Life Sciences / Bortezomib / Bortezomib - pharmacology / Bortezomib - therapeutic use / Cancer therapies / Cell activation / Cell cycle / Cell Line, Tumor / Cell survival / Chymotrypsin / Cyclin-dependent kinases / Cytotoxicity / Development and progression / Dosage and administration / Drug therapy / Endoplasmic reticulum / Endoplasmic Reticulum Stress / Enzyme inhibitors / ER stress / ErbB-2 protein / Extracellular signal-regulated kinase / Health aspects / Humans / Immune response / In vivo methods and tests / Inhibitor drugs / Intravenous administration / Kinases / Life Sciences / Lymphocytes / Lymphocytes T / Lymphoma / Malignant mesothelioma / Mantle cell lymphoma / Medical prognosis / Mesothelioma / Mesothelioma, Malignant - drug therapy / Mice / Mice, Inbred C57BL / Modulation / Multiple myeloma / Non-Hodgkin's lymphomas / Physiological aspects / Prognosis / Proteasome / Proteasomes / Protein folding / Proteins / Solid tumors / Stress (Physiology) / Survival / T cells / T-Lymphocytes / Targeted cancer therapy / Testing / Toxicity / Tumor Microenvironment / Tumors