Immunostimulatory Effects of Melphalan and Usefulness in Adoptive Cell Therapy with Antitumor CD4+ T Cells

Abstract

The alkylating agent melphalan is used in the treatment of hematological malignancies, especially multiple myeloma. In the past, the usefulness of melphalan has been solely attributed to its cytotoxicity on fast-growing cancerous cells. Although the immunomodulatory effects of melphalan were suggested many years ago, only recently has this aspect of melphalan’s activity begun to be elucidated at the molecular level. Emerging evidence indicates that melphalan can foster an immunogenic microenvironment by inducing immunogenic cell death (ICD) as characterized by membrane translocation of endoplasmic reticulum protein calreticulin (CRT) and by release of chromatin-binding protein high-mobility group box 1 (HMGB1). In addition, the lympho-depletive effect of melphalan can induce the release of pro-inflammatory cytokines and growth factors, deplete regulatory T cells, and create space to facilitate the expansion of infused tumor-reactive T cells. These features suggest that melphalan can be used as a preparative chemotherapy for adoptive T-cell therapy. This notion is supported by our recent work demonstrating that the combination of melphalan and adoptive transfer of tumor-reactive CD4+ T cells can mediate potent antitumor effects in animal models. This review summarizes the recent advances in understanding and utilizing the immunomodulatory effects of melphalan.

Synthesis, Characterization, and In Vitro Studies of an Reactive Oxygen Species (ROS)-Responsive Methoxy Polyethylene Glycol-Thioketal-Melphalan Prodrug for Glioblastoma Treatment

“…At the end of the experiment, concerning prodrugs administrations, the normalized cell index of free MPH treated cells was~245-fold lower in healthy cells, describing a very low selectivity toward cancer versus healthy cells as described by several studies, and the frequent side-effects of free MPH (Kühne et al, 2009;Kuczma et al, 2016). Remarkably, from analysis of the normalized cell index ratio between mPEG-TK-MPH and free MPH in both types of cells ( Figures 3A, B), we can conclude that mPEG-TK-MPH was significantly favorable in terms of safety treated in healthy cells with minimal toxicity and showed good selectivity in the case of cancer cells, with normalized cell index ratios at 48 h treatment of (295 vs 1.8, respectively).…”

“…This may be due to a higher cell uptake favored by L-type amino acid transporters (LATs) (Kühne et al, 2009) (as L-type amino acid transporter 1, LAT1), which transport neutral amino acids, including leucine. This transporter is present also in glioma cells, including C6 (Lin et al, 2004;Nawashiro et al, 2005;Nawashiro et al, 2006;Kuczma et al, 2016), and can promote MPH active transport into cells (Lin et al, 2004). In addition, taking into consideration its hydrophobic nature, passive transport of the free form of the drug cannot be excluded (Kühne et al, 2009).…”

“…P-gps are one of main reasons for the limited efficacy of chemotherapeutic drugs in GBM, being responsible for efflux events of cytotoxic drugs from the cancer cells (Kirtane et al, 2013) and even at the BBB level. This favorable feature is particularly needed in the case of MPH, with an in vivo a circulation half-life of only 75 min (Kuczma et al, 2016).…”

A new parameter in multiple myeloma: CYP3A4*1B single nucleotide polymorphism

“…Examining the literature data between the treatments of the patients included in our study and their relationship with p450 seems important in terms of explaining the significant differences we obtained in terms of OS and PFS. It is necessary to mention the publications on the relationship between bortezomib, cyclophosphamide, dexamethasone, lenalidomide, and the p450 enzyme system and melphalan used in ASCT [18][19][20][21][22].…”

“…Melphalan is eliminated by both renal excretion and spontaneous chemical degradation to its mono-and di-hydroxy metabolites. Therefore, no relationship has been described between the p450 system and melphalan activity [21,22]. Studies on lenalidomide have also shown that it has no effect on any of p450 cytochrome enzymes [23].…”