Repurposing a psychoactive drug for children with cancer: p27Kip1-dependent inhibition of metastatic neuroblastomas by Prozac

EV20/Omomyc: A novel dual MYC/HER3 targeting immunoconjugate

MYC is one of the most important therapeutic targets in human cancer. Many attempts have been made to develop small molecules that could be used to curb its activity in patients, but most failed to identify a suitable direct inhibitor. After years of preclinical characterization, a tissue-penetrating peptide MYC inhibitor, called Omomyc, has been recently successfully used in a Phase I dose escalation study in late-stage, all-comers solid tumour patients. The study showed drug safety and positive signs of clinical activity, prompting the beginning of a new Phase Ib combination study currently ongoing in metastatic pancreatic adenocarcinoma patients. In this manuscript, we have explored the possibility to improve Omomyc targeting to specific cancer subtypes by linking it to a therapeutic antibody. The new immunoconjugate, called EV20/Omomyc, was developed by linking a humanised anti-HER3 antibody, named EV20, to Omomyc using a bifunctional linker. EV20/Omomyc shows antigen-dependent penetrating activity and therapeutic efficacy in a metastatic model of neuroblastoma. This study suggests that directing Omomyc into specific cell types using antibodies recognising tumour antigens could improve its therapeutic activity in specific indications, like in the paediatric setting.

Repurposing fluoxetine to treat lymphocytic leukemia: Apoptosis induction, sigma-1 receptor upregulation, inhibition of IL-2 cytokine production, and autophagy induction

BACKGROUND

Childhood cancer has a cure rate of as low as 15% in low-income countries, suggesting a need for cheaper treatment options. Fluoxetine is a thoroughly safety-tested drug that may target the sigma-1 receptor (σ1-R).

RESEARCH DESIGN AND METHODS

Using the human leukemic cell line, Jurkat, we investigated the effects of fluoxetine on cell survival using XTT and trypan blue staining. Apoptosis was measured using AnnexinV/PI staining and western blot analysis of caspase cleavage. IL-2 secretion of Jurkat cells in response to PHA/PMA was measured using ELISA, and the expression of AKT/pAKT and the σ1-R were measured using western blotting.

RESULTS

Fluoxetine-induced apoptosis and G-2 cell cycle arrest. Fluoxetine reduced IL-2 secretion dose-dependently and could be further potentiated by σ1-R antagonist BD1047 (P < 0.05). Fluoxetine inhibited pAKT six hours post-treatment (P < 0.05). The expression of the σ1-R showed a significant increase between 12 to 48 hours in Jurkat cells (P < 0.05). At the same time, there was a substantial increase in autophagy.

CONCLUSIONS

Fluoxetine may have the potential for acute leukemia treatment. Co-treatment with a σ1-R antagonist increases fluoxetine-induced apoptosis, possibly targeting AKT phosphorylation and autophagy activation.

Multiple approaches to repurposing drugs for neuroblastoma

Neuroblastoma (NB) is the second leading extracranial solid tumor of early childhood with about two-thirds of cases presenting before the age of 5, and accounts for roughly 15 percent of all pediatric cancer fatalities in the United States. Treatments against NB are lacking, resulting in a low survival rate in high-risk patients. A repurposing approach using already approved or clinical stage compounds can be used for diseases for which the patient population is small, and the commercial market limited. We have used Bayesian machine learning, in vitro cell assays, and combination analysis to identify molecules with potential use for NB. We demonstrated that pyronaridine (SH-SY5Y IC50 1.70 µM, SK-N-AS IC50 3.45 µM), BAY 11-7082 (SH-SY5Y IC50 0.85 µM, SK-N-AS IC50 1.23 µM), niclosamide (SH-SY5Y IC50 0.87 µM, SK-N-AS IC50 2.33 µM) and fingolimod (SH-SY5Y IC50 4.71 µM, SK-N-AS IC50 6.11 µM) showed cytotoxicity against NB. As several of the molecules are approved drugs in the US or elsewhere, they may be repurposed more readily for NB treatment. Pyronaridine was also tested in combinations in SH-SY5Y cells and demonstrated an antagonistic effect with either etoposide or crizotinib. Whereas when crizotinib and etoposide were combined with each other they had a synergistic effect in these cells. We have also described several analogs of pyronaridine to explore the structure-activity relationship against cell lines. We describe multiple molecules demonstrating cytotoxicity against NB and the further evaluation of these molecules and combinations using other NB cells lines and in vivo models will be important in the future to assess translational potential.

Hexosomes as Efficient Platforms for Possible Fluoxetine Hydrochloride Repurposing with Improved Cytotoxicity against HepG2 Cells

The aim of this study was to investigate the feasibility of hexosomes (HEXs) as competent platforms for fluoxetine hydrochloride (FH) repurposing against HepG2 hepatocellular carcinoma. Different FH-loaded HEX formulations were prepared and optimized by the hot emulsification method. The HEX features such as particle size, ζ potential, and drug entrapment efficiency (EE%) can be tailored by tuning HEX components and fabrication conditions. The composition of the optimized FH hexosome (OFH-HEX) was composed of 3.1, 1.4, 0.5, 0.2, and 94.8% for glyceryl monooleate, oleic acid, pluronic F127, FH, and deionized water, respectively. The anionic OFH-HEX with a particle size of 145.5 ± 2.5 nm and drug EE% of 45.4 ± 1.2% was able to prolong the in vitro FH release, where only 19.5 ± 2.3% released in phosphate-buffered saline (PBS) pH 7.4 after 24 h. Contrarily, HEX rapidly released FH in acetate buffer pH 5.5 and achieved a 90.5 ± 4.7% release after 24 h. The obtained HEX showed an improved cellular internalization in a time-dependent manner and enhanced the cytotoxicity (2-fold higher than FH solution). The current study suggests the potential of FH-HEX as a possible anticancer agent against hepatocellular carcinoma.

Targeting Vesicular LGALS3BP by an Antibody-Drug Conjugate as Novel Therapeutic Strategy for Neuroblastoma

Simple Summary

Antibody Drug Conjugates are an emerging class of biopharmaceuticals that have seen an impressive increase of attention in the field of cancer therapy. Here, we describe the therapeutic activity of 1959-sss/DM3, a non-internalizing ADC targeting LGALS3BP, a secreted, extracellular vesicles-associated protein expressed by the majority of human cancers, including neuroblastoma. We show that 1959-sss/DM3 treatment can cure mice with established neuroblastoma tumours in pseudometastatic, orthotopic and Patient Derived Xenograft models.

Abstract

Neuroblastoma is the most common extra-cranial solid tumor in infants and children, which accounts for approximately 15% of all cancer-related deaths in the pediatric population. New therapeutic modalities are urgently needed. Antibody-Drug Conjugates (ADC)s-based therapy has been proposed as potential strategy to treat this pediatric malignancy. LGALS3BP is a highly glycosylated protein involved in tumor growth and progression. Studies have shown that LGALS3BP is enriched in extracellular vesicles (EV)s derived by most neuroblastoma cells, where it plays a critical role in preparing a favorable tumor microenvironment (TME) through direct cross talk between cancer and stroma cells. Here, we describe the development of a non-internalizing LGALS3BP ADC, named 1959-sss/DM3, which selectively targets LGALS3BP expressing neuroblastoma. 1959-sss/DM3 mediated potent therapeutic activity in different types of neuroblastoma models. Notably, we found that treatments were well tolerated at efficacious doses that were fully curative. These results offer preclinical proof-of-concept for an ADC targeting exosomal LGALS3BP approach for neuroblastomas.

Emerging therapeutic targets for neuroblastoma

INTRODUCTION

Neuroblastoma (NB) is the prime cancer of infancy, and accounts for 9% of pediatric cancer deaths. While children diagnosed with clinically stable NB experience a complete cure, those with high-risk disease (HR-NB) do not recover, despite intensive therapeutic strategies. Development of novel and effective targeted therapies is needed to counter disease progression, and to benefit long-term survival of children with HR-NB.

AREAS COVERED

Recent studies (2017-2020) pertinent to NB evolution are selectively reviewed to recognize novel and effective therapeutic targets. The prospective and promising therapeutic targets/strategies for HR-NB are categorized into (a) targeting oncogene-like and/or reinforcing tumor suppressor (TS)-like lncRNAs; (b) targeting oncogene-like microRNAs (miRs) and/or mimicking TS-miRs; (c) targets for immunotherapy; (d) targeting epithelial-to-mesenchymal transition and cancer stem cells; (e) novel and beneficial combination approaches; and (f) repurposing drugs and other strategies in development.

EXPERT OPINION

It is highly unlikely that agents targeting a single candidate or signaling will be beneficial for an HR-NB cure. We must develop efficient drug deliverables for functional targets, which could be integrated and advance clinical therapy. Fittingly, the looming evidence indicated an aggressive evolution of promising novel and integrative targets, development of efficient drugs, and improvised strategies for HR-NB treatment.