Glioblastoma: synergy of growth promotion between CCL5 and NK-1R can be thwarted by blocking CCL5 with miraviroc, an FDA approved anti-HIV drug and blocking NK-1R with aprepitant, an FDA approved anti-nausea drug

The combined anti-tumor effects of 5-fluorouracil and neurokinin receptor inhibitor, aprepitant, against colorectal cancer: In vitro and in vivo study

BACKGROUND

Colorectal cancer (CRC) is one of the world's largest health concerns with growing global incidence and mortality. The potential value of the neurokinin-1 receptor as a therapeutic target has been reported in several tumor types, including CRC. Here we examined the potential anti-tumor effects of a clinically approved neurokinin-1 receptor antagonist, aprepitant, alone and its combination with 5-Fluorouracil (5-FU) as a first choice CRC chemotherapeutic drug, in both in vitro and in vivo models of CRC.

METHODS

MTT assay was employed for assessing cell proliferation. mRNA expression levels were determined by quantitative real-time PCR (qRT-PCR). Flow cytometric analysis of apoptosis was performed using an Annexin-V/propidium iodide assay kit. We finally conducted an in vivo experiment in a mouse model of CRC to confirm the in vitro antiproliferative activity of aprepitant and 5-FU.

RESULTS

We found that aprepitant and 5-FU significantly reduced CRC cell viability. The combination of drugs exhibited potent synergistic growth inhibitory effects on CRC cells. Moreover, aprepitant and 5-FU induced apoptosis and altered the levels of apoptotic genes (up-regulation of Bax, and p53 along with downregulation of Bcl-2). Importantly, the aprepitant and 5-FU combination showed a more pronounced impact on apoptosis and associated genes than either of the agents alone. Furthermore, aprepitant reduced tumor growth in vivo and led to significantly longer survival time, and this effect was more prominent when using the aprepitant and 5-FU combination.

CONCLUSIONS

Collectively, combinatory treatment with aprepitant and 5-FU potentially exerts synergistic growth inhibition and apoptosis induction in CRC, deserving further consideration as a novel strategy for CRC patients.

The OSR9 Regimen: A New Augmentation Strategy for Osteosarcoma Treatment Using Nine Older Drugs from General Medicine to Inhibit Growth Drive

As things stand in 2023, metastatic osteosarcoma commonly results in death. There has been little treatment progress in recent decades. To redress the poor prognosis of metastatic osteosarcoma, the present regimen, OSR9, uses nine already marketed drugs as adjuncts to current treatments. The nine drugs in OSR9 are: (1) the antinausea drug aprepitant, (2) the analgesic drug celecoxib, (3) the anti-malaria drug chloroquine, (4) the antibiotic dapsone, (5) the alcoholism treatment drug disulfiram, (6) the antifungal drug itraconazole, (7) the diabetes treatment drug linagliptin, (8) the hypertension drug propranolol, and (9) the psychiatric drug quetiapine. Although none are traditionally used to treat cancer, all nine have attributes that have been shown to inhibit growth-promoting physiological systems active in osteosarcoma. In their general medicinal uses, all nine drugs in OSR9 have low side-effect risks. The current paper reviews the collected data supporting the role of OSR9.

The in vitro anti-cancer synergy of neurokinin-1 receptor antagonist, aprepitant, and 5-aminolevulinic acid in glioblastoma

Glioblastoma multiforme (GBM) is the most malignant type of cerebral neoplasm in adults with a poor prognosis. Currently, combination therapy with different anti-cancer agents is at the forefront of GBM research. Hence, this study aims to evaluate the potential anti-cancer synergy of a clinically approved neurokinin-1 receptor antagonist, aprepitant, and 5-aminolevulinic acid (5-ALA), a prodrug that elicits fluorescent porphyrins in gliomas on U-87 human GBM cells. We found that aprepitant and 5-ALA effectively inhibited GBM cell viability. The combinatorial treatment of these drugs exerted potent synergistic growth inhibitory effects on GBM cells. Moreover, aprepitant and 5-ALA induced apoptosis and altered the levels of apoptotic genes (up-regulation of Bax and P53 along with downregulation of Bcl-2). Furthermore, aprepitant and 5-ALA increased the accumulation of protoporphyrin IX, a highly pro-apoptotic and fluorescent photosensitizer. Aprepitant and 5-ALA significantly inhibited GBM cell migration and reduced matrix metalloproteinases (MMP-2 and MMP-9) activities. Importantly, all these effects were more prominent following aprepitant-5-ALA combination treatment than either drug alone. Collectively, the combination of aprepitant and 5-ALA leads to considerable synergistic anti-proliferative, pro-apoptotic, and anti-migratory effects on GBM cells and provides a firm basis for further evaluation of this combination as a novel therapeutic approach for GBM.

Novel trajectories of the NK1R antagonist aprepitant in rotenone-induced Parkinsonism-like symptoms in rats: Involvement of ERK5/KLF4/p62/Nrf2 signaling axis

Regulation of the interplay between autophagy and oxidative stress is vital in maintaining neuronal homeostasis during neurotoxicity. The interesting involvement of NK1 receptor (NK1R) in neurodegeneration has highlighted the value of investigating the neuroprotective effect of aprepitant (Aprep), an NK1R antagonist in Parkinson's disease (PD). This study was conducted to disclose Aprep's ability to modulate extracellular signal-regulated kinase 5/Krüppel-like factor 4 (ERK5/KLF4) cue as molecular signaling implicated in regulating autophagy and redox signaling in response to rotenone neurotoxicity. Rotenone (1.5 mg/kg) was administered on alternate days, and rats were given Aprep simultaneously with or without PD98059, an ERK inhibitor, for 21 days. Aprep ameliorated motor deficits as verified by restored histological features, and intact neurons count in SN and striata along with tyrosine hydroxylase immunoreactivity in SN. The molecular signaling of Aprep was illustrated by the expression of KLF4 following the phosphorylation of its upstream target, ERK5. Nuclear factor erythroid 2-related factor 2 (Nrf2) was up-regulated, shifting the oxidant/antioxidant balance towards the antioxidant side, as evidenced by elevated GSH and suppressed MDA levels. In parallel, Aprep noticeably reduced phosphorylated α-synuclein aggregates due to autophagy induction as emphasized by marked LC3II/LC3I elevation and p62 level reduction. These effects were diminished upon PD98059 pre-administration. In conclusion, Aprep showed neuroprotective effects against rotenone-induced PD, which may be partially attributed to the activation of the ERK5/KLF4 signaling pathway. It modulated p62-mediated autophagy and Nrf2 axis which act cooperatively to counter rotenone-associated neurotoxicity pointing to Aprep's prospect as a curious candidate in PD research.

Discovery of a New CaMKII-Targeted Synthetic Lethal Therapy against Glioblastoma Stem-like Cells

Glioblastoma stem-like cells (GSCs) drive tumor initiation, cancer invasion, immune evasion, and therapeutic resistance and are thus a key therapeutic target for improving treatment for glioblastoma multiforme (GBM). We previously identified calcium/calmodulin-dependent protein kinase II (CaMKII) as an emerging molecular target for eliminating GSCs. In this study, we aim to explore a new CaMKII-targeted synthetic lethal therapy for GSCs. Through high-throughput drug combination screening using CaMKII inhibitors and a bioactive compound library in GSCs, neurokinin 1 receptor (NK1R) inhibitors such as SR 140333 and aprepitant are found to be potential anticancer agents that exhibit chemical synthetic lethal interactions with CaMKII inhibitors, including hydrazinobenzoylcurcumin (HBC), berbamine, and KN93. Combined treatment with NK1R and CaMKII inhibitors markedly suppresses the viability and neurosphere formation of U87MG- and U373MG-derived GSCs. In addition, the combination of HBC and NK1R inhibitors significantly inhibits U87MG GSC tumor growth in a chick embryo chorioallantoic membrane (CAM) model. Furthermore, the synthetic lethal interaction is validated using RNA interference of CaMKIIγ and NK1R. Notably, the synthetic lethal effects in GSCs are associated with the activation of caspase-mediated apoptosis by inducing p53 expression and reactive oxygen species generation, as well as the suppression of stemness marker expression by reducing nuclear factor-kappa B (NF-κB) activity. This follows the downregulation of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling and a decrease in intracellular calcium concentration. Moreover, NK1R affects CaMKIIγ activation. These findings demonstrate that NK1R is a potential synthetic lethal partner of CaMKII that is involved in eradicating GSCs, and they suggest a new CaMKII-targeted combination therapy for treating GBM.

An Update on Glioblastoma Biology, Genetics, and Current Therapies: Novel Inhibitors of the G Protein-Coupled Receptor CCR5

The mechanisms governing therapeutic resistance of the most aggressive and lethal primary brain tumor in adults, glioblastoma, have increasingly focused on tumor stem cells. These cells, protected by the periarteriolar hypoxic GSC niche, contribute to the poor efficacy of standard of care treatment of glioblastoma. Integrated proteogenomic and metabolomic analyses of glioblastoma tissues and single cells have revealed insights into the complex heterogeneity of glioblastoma and stromal cells, comprising its tumor microenvironment (TME). An additional factor, which isdriving poor therapy response is the distinct genetic drivers in each patient's tumor, providing the rationale for a more individualized or personalized approach to treatment. We recently reported that the G protein-coupled receptor CCR5, which contributes to stem cell expansion in other cancers, is overexpressed in glioblastoma cells. Overexpression of the CCR5 ligand CCL5 (RANTES) in glioblastoma completes a potential autocrine activation loop to promote tumor proliferation and invasion. CCL5 was not expressed in glioblastoma stem cells, suggesting a need for paracrine activation of CCR5 signaling by the stromal cells. TME-associated immune cells, such as resident microglia, infiltrating macrophages, T cells, and mesenchymal stem cells, possibly release CCR5 ligands, providing heterologous signaling between stromal and glioblastoma stem cells. Herein, we review current therapies for glioblastoma, the role of CCR5 in other cancers, and the potential role for CCR5 inhibitors in the treatment of glioblastoma.

The Neurokinin-1 Receptor Antagonist Aprepitant: An Intelligent Bullet against Cancer?

Neurokinin-1 receptor (NK-1R) antagonists exert antitumor action, are safe and do not cause serious side-effects. These antagonists (via the NK-1R) exert multiple actions against cancer: antiproliferative and anti-Warburg effects and apoptotic, anti-angiogenic and antimetastatic effects. These multiple effects have been shown for a broad spectrum of cancers. The drug aprepitant (an NK-1R antagonist) is currently used in clinical practice as an antiemetic. In in vivo and in vitro studies, aprepitant also showed the aforementioned multiple antitumor actions against many types of cancer. A successful combination therapy (aprepitant and radiotherapy) has recently been reported in a patient suffering from lung carcinoma: the tumor mass disappeared and side-effects were not observed. Aprepitant could be considered as an intelligent bullet against cancer. The administration of aprepitant in cancer patients to prevent recurrence and metastasis after surgical procedures, thrombosis and thromboembolism is discussed, as is the possible link, through the substance P (SP)/NK-1R system, between cancer and depression. Our main aim is to review the multiple antitumor actions exerted by aprepitant, and the use of this drug is suggested in cancer patients. Altogether, the data support the reprofiling of aprepitant for a new therapeutic use as an antitumor agent.

CCR5-Mediated Signaling Is Involved in Invasion of Glioblastoma Cells in Its Microenvironment

The chemokine CCL5/RANTES is a versatile inflammatory mediator, which interacts with the receptor CCR5, promoting cancer cell interactions within the tumor microenvironment. Glioblastoma is a highly invasive tumor, in which CCL5 expression correlates with shorter patient survival. Using immunohistochemistry, we identified CCL5 and CCR5 in a series of glioblastoma samples and cells, including glioblastoma stem cells. CCL5 and CCR5 gene expression were significantly higher in a cohort of 38 glioblastoma samples, compared to low-grade glioma and non-cancerous tissues. The in vitro invasion of patients-derived primary glioblastoma cells and glioblastoma stem cells was dependent on CCL5-induced CCR5 signaling and is strongly inhibited by the small molecule CCR5 antagonist maraviroc. Invasion of these cells, which was enhanced when co-cultured with mesenchymal stem cells (MSCs), was inhibited by maraviroc, suggesting that MSCs release CCR5 ligands. In support of this model, we detected CCL5 and CCR5 in MSC monocultures and glioblastoma-associated MSC in tissue sections. We also found CCR5 expressing macrophages were in close proximity to glioblastoma cells. In conclusion, autocrine and paracrine cross-talk in glioblastoma and, in particular, glioblastoma stem cells with its stromal microenvironment, involves CCR5 and CCL5, contributing to glioblastoma invasion, suggesting the CCL5/CCR5 axis as a potential therapeutic target that can be targeted with repositioned drug maraviroc.

Antitumor action of temozolomide, ritonavir and aprepitant against human glioma cells

In the effort to find better treatments for glioblastoma we tested several currently marketed non-chemotherapy drugs for their ability to enhance the standard cytotoxic drug currently used to treat glioblastoma- temozolomide. We tested four antiviral drugs- acyclovir, cidofovir, maraviroc, ritonavir, and an anti-emetic, aprepitant. We found no cytotoxicity of cidofovir and discussed possible reasons for discrepancy from previous findings of others. We also found no cytotoxicity from acyclovir or maraviroc also in contradistinction to predictions. Cytotoxicity to glioma cell line GAMG for temozolomide alone was 14%, aprepitant alone 7%, ritonavir alone 14%, while temozolomide + aprepitant was 19%, temozolomide + ritonavir 34%, ritonavir + aprepitant 64 %, and all three, temozolomide + ritonavir + aprepitant 78%. We conclude that a remarkable synergy exists between aprepitant and ritonavir. Given the long clinical experience with these two well-tolerated drugs in treating non-cancer conditions, and the current median survival of glioblastoma of 2 years, a trial is warranted of adding these two simple drugs to current standard treatment with temozolomide.

CUSP9* treatment protocol for recurrent glioblastoma: aprepitant, artesunate, auranofin, captopril, celecoxib, disulfiram, itraconazole, ritonavir, sertraline augmenting continuous low dose temozolomide

CUSP9 treatment protocol for recurrent glioblastoma was published one year ago. We now present a slight modification, designated CUSP9*. CUSP9* drugs--aprepitant, artesunate, auranofin, captopril, celecoxib, disulfiram, itraconazole, sertraline, ritonavir, are all widely approved by regulatory authorities, marketed for non-cancer indications. Each drug inhibits one or more important growth-enhancing pathways used by glioblastoma. By blocking survival paths, the aim is to render temozolomide, the current standard cytotoxic drug used in primary glioblastoma treatment, more effective. Although esthetically unpleasing to use so many drugs at once, the closely similar drugs of the original CUSP9 used together have been well-tolerated when given on a compassionate-use basis in the cases that have come to our attention so far. We expect similarly good tolerability for CUSP9*. The combined action of this suite of drugs blocks signaling at, or the activity of, AKT phosphorylation, aldehyde dehydrogenase, angiotensin converting enzyme, carbonic anhydrase -2,- 9, -12, cyclooxygenase-1 and -2, cathepsin B, Hedgehog, interleukin-6, 5-lipoxygenase, matrix metalloproteinase -2 and -9, mammalian target of rapamycin, neurokinin-1, p-gp efflux pump, thioredoxin reductase, tissue factor, 20 kDa translationally controlled tumor protein, and vascular endothelial growth factor. We believe that given the current prognosis after a glioblastoma has recurred, a trial of CUSP9* is warranted.

Novel anti-glioblastoma agents and therapeutic combinations identified from a collection of FDA approved drugs

Background

Glioblastoma (GBM) is a therapeutic challenge, associated with high mortality. More effective GBM therapeutic options are urgently needed. Hence, we screened a large multi-class drug panel comprising the NIH clinical collection (NCC) that includes 446 FDA-approved drugs, with the goal of identifying new GBM therapeutics for rapid entry into clinical trials for GBM.

Methods

Screens using human GBM cell lines revealed 22 drugs with potent anti-GBM activity, including serotonergic blockers, cholesterol-lowering agents (statins), antineoplastics, anti-infective, anti-inflammatories, and hormonal modulators. We tested the 8 most potent drugs using patient-derived GBM cancer stem cell-like lines. Notably, the statins were active in vitro; they inhibited GBM cell proliferation and induced cellular autophagy. Moreover, the statins enhanced, by 40-70 fold, the pro-apoptotic activity of irinotecan, a topoisomerase 1 inhibitor currently used to treat a variety of cancers including GBM. Our data suggest that the mechanism of action of statins was prevention of multi-drug resistance protein MDR-1 glycosylation. This drug combination was synergistic in inhibiting tumor growth in vivo. Compared to animals treated with high dose irinotecan, the drug combination showed significantly less toxicity.

Results

Our data identifies a novel combination from among FDA-approved drugs. In addition, this combination is safer and well tolerated compared to single agent irinotecan.

Conclusions

Our study newly identifies several FDA-approved compounds that may potentially be useful in GBM treatment. Our findings provide the basis for the rational combination of statins and topoisomerase inhibitors in GBM.

A conceptually new treatment approach for relapsed glioblastoma: coordinated undermining of survival paths with nine repurposed drugs (CUSP9) by the International Initiative for Accelerated Improvement of Glioblastoma Care

To improve prognosis in recurrent glioblastoma we developed a treatment protocol based on a combination of drugs not traditionally thought of as cytotoxic chemotherapy agents but that have a robust history of being well-tolerated and are already marketed and used for other non-cancer indications. Focus was on adding drugs which met these criteria: a) were pharmacologically well characterized, b) had low likelihood of adding to patient side effect burden, c) had evidence for interfering with a recognized, well-characterized growth promoting element of glioblastoma, and d) were coordinated, as an ensemble had reasonable likelihood of concerted activity against key biological features of glioblastoma growth. We found nine drugs meeting these criteria and propose adding them to continuous low dose temozolomide, a currently accepted treatment for relapsed glioblastoma, in patients with recurrent disease after primary treatment with the Stupp Protocol. The nine adjuvant drug regimen, Coordinated Undermining of Survival Paths, CUSP9, then are aprepitant, artesunate, auranofin, captopril, copper gluconate, disulfiram, ketoconazole, nelfinavir, sertraline, to be added to continuous low dose temozolomide. We discuss each drug in turn and the specific rationale for use- how each drug is expected to retard glioblastoma growth and undermine glioblastoma's compensatory mechanisms engaged during temozolomide treatment. The risks of pharmacological interactions and why we believe this drug mix will increase both quality of life and overall survival are reviewed.

Aldehyde dehydrogenase and HSP90 co-localize in human glioblastoma biopsy cells

The concept of a stem cell subpopulation as understood from normal epithelial tissue or bone marrow function has been extended to our understanding of cancer tissue and is now the target of treatment efforts specifically directed to this subpopulation. In glioblastoma, as well as in other cancers, increased expression of aldehyde dehydrogenase (ALDH) has been found localized within a minority sub-population of tumor cells which demonstrate stem cell properties. A separate body of research associated increased expression of heat-shock protein-90 (HSP90) with stem cell attributes. We present here results from our initial immunohistochemistry study of human glioblastoma biopsy tissue where both ALDH and HSP90 tended to be co-expressed in high amounts in the same minority of cells. Since 12% of all cells in the six biopsies studied were ALDH positive and 17% were HSP90 positive, by chance alone 2% would have been expected to be positive for both. In fact 7% of all cells simultaneously expressed both markers-a significant difference (p = 0.037). That two previously identified proteins associated with stem cell attributes tend to be co-expressed in the same individual glioblastoma cells might have clinical utility. Disulfiram, used to treat alcoholism for half-a century now, is a potent ALDH inhibitor and the old anti-viral drug ritonavir inhibits HSP90. These should be explored for the potential to retard aspects of glioblastoma stem cells' function subserved by ALDH and HSP90.

Glioblastoma chemotherapy adjunct via potent serotonin receptor-7 inhibition using currently marketed high-affinity antipsychotic medicines

Glioblastoma treatment as now constituted offers increased survival measured in months over untreated patients. Because glioblastomas are active in synthesizing a bewildering variety of growth factors, a systematic approach to inhibiting these is being undertaken as treatment adjunct. The serotonin 7 receptor is commonly overexpressed in glioblastoma. Research documentation showing agonists at serotonin receptor 7 cause increased extracellular regulated kinase 1/2 activation, increased interleukin-6 synthesis, increased signal transducer and activator of transcription-3 activation, increased resistance to apoptosis and other growth enhancing changes in glioblastoma is reviewed in this paper. Because three drugs in wide use to treat thought disorders - paliperidone, pimozide and risperidone - are also potent and well-tolerated inhibitors at serotonin receptor 7, these drugs should be studied for growth factor deprivation in an adjunctive role in glioblastoma treatment.

Acyclovir inhibition of IDO to decrease Tregs as a glioblastoma treatment adjunct

Regulatory T cells, Tregs, are a subset of lymphocytes that have immunosuppressive attributes. They are elevated in blood of glioblastoma patients and within this tumor's tissue itself. Indoleamine 2,3-dioxygenase, IDO, converts tryptophan to kynurenine. IDO activity enhances Treg formation by pathways that are unknown. Experimentally, inhibition of IDO decreases Treg function and number in rodents. The common anti-viral agent acyclovir inhibits IDO. Acyclovir may thereby decrease Treg function in glioblastoma. If it can be confirmed that Treg counts are elevated in glioblastoma patients' tumor tissue, and if we can document acyclovir's lowering of tissue Treg counts by a small trial of acyclovir in pre-operative glioblastoma patients, a trial of acyclovir effect on survival should be done given the current poor prognosis of glioblastoma and the well-established safety and low side effect burden of acyclovir.