A chemical screen identifies trifluoperazine as an inhibitor of glioblastoma growth

Benzotriazole Ultraviolet Stabilizers (BUVSs) as Potential Protein Kinase Antagonists in Rice

The ubiquitous occurrence of benzotriazole ultraviolet stabilizers (BUVSs) in the environment and organisms has warned of their potential ecological and health risks. Studies showed that some BUVSs exerted immune and chronic toxicities to animals by disturbing signaling transduction, yet limited research has investigated the toxic effects on crop plants and the underlying mechanisms of signaling regulation. Herein, a laboratory-controlled hydroponic experiment was conducted on rice to explore the phytotoxicity of BUVSs by integrating conventional biochemical experiments, transcriptomic analysis, competitive sorption assays, and computational studies. The results showed that BUVSs inhibited the growth of rice by 6.30-20.4% by excessively opening the leaf stomas, resulting in increased transpiration. BUVSs interrupted the transduction of abscisic acid (ABA) signal through competitively binding to Ca2+-dependent protein kinase (CDPK), weakening the CDPK phosphorylation and further inhibiting the downstream signaling. As structural analogues of ATP, BUVSs acted as potential ABA signaling antagonists, leading to physiological dysfunction in mediating stomatal closure under stresses. This is the first comprehensive study elucidating the effects of BUVSs on the function of key proteins and the associated signaling transduction in plants and providing insightful information for the risk evaluation and control of BUVSs.

Effect of l-Dopa in acute temozolomide-induced cognitive impairment in male mice: a possible antineuroinflammatory role

Temozolomide is used commonly in the treatment of some types of cancers, but it may also result in cognitive impairments such as memory deficits. l-Dopa, a well known medicine for the central nervous system, has been shown to have positive effects on some cognitive disorders. Here we sought to investigate the effect of l-Dopa on temozolomide-induced cognitive impairments. BALB/c mice were subjected to 3-days temozolomide and 6-days concomitant l-Dopa/benserazide administration in six groups (control, l-Dopa 25 mg/kg, l-Dopa 75 mg/kg, temozolomide, temozolomide + l-Dopa 25 mg/kg, and temozolomide + l-Dopa 75 mg/kg). Open field test, object location recognition, novel object recognition test, and shuttle-box test were carried out to determine the locomotor, anxiety-like behavior, and memory function of subjects. TNF-α and brain-derived neurotrophic factor (BDNF) gene expression in the hippocampus was measured by real-time PCR. Mice treated with temozolomide showed recognition memory impairment, along with hippocampal TNF-α and BDNF mRNA expression level raise, and detection of histological insults in hematoxylin and eosin hippocampal slides. Mice that received temozolomide + l-Dopa showed normal behavioral function and lower TNF-α and BDNF hippocampal mRNA expression levels, and histologically normal hippocampal CA1 region in comparison with mice in the temozolomide group. Our results provide evidence that l-Dopa prevents temozolomide-induced recognition memory deficit in mice at the acute phase probably via l-Dopa antineuroinflammatory effects.

Targeting Ca2+ and Mitochondrial Homeostasis by Antipsychotic Thioridazine in Leukemia Cells

Mitochondria have pivotal roles in cellular physiology including energy metabolism, reactive oxygen species production, Ca2+ homeostasis, and apoptosis. Altered mitochondrial morphology and function is a common feature of cancer cells and the regulation of mitochondrial homeostasis has been identified as a key to the response to chemotherapeutic agents in human leukemias. Here, we explore the mechanistic aspects of cytotoxicity produced by thioridazine (TR), an antipsychotic drug that has been investigated for its anticancer potential in human leukemia cellular models. TR exerts selective cytotoxicity against human leukemia cells in vitro. A PCR array provided a general view of the expression of genes involved in cell death pathways. TR immediately produced a pulse of cytosolic Ca2+, followed by mitochondrial uptake, resulting in mitochondrial permeabilization, caspase 9/3 activation, endoplasmic reticulum stress, and apoptosis. Ca2+ chelators, thiol reducer dithiothreitol, or CHOP knockdown prevented TR-induced cell death. TR also exhibited potent cytotoxicity against BCL-2/BCL-xL-overexpressing leukemia cells. Additionally, previous studies have shown that TR exhibits potent antitumor activity in vivo in different solid tumor models. These findings show that TR induces a Ca2+-mediated apoptosis with involvement of mitochondrial permeabilization and ER stress in leukemia and it emphasizes the pharmacological potential of TR as an adjuvant in antitumor chemotherapy.

Anticancer efficacy of endo- and exogenous potent ligands acting at dopaminergic receptor-expressing cancer cells

Cancer is one of the most common and dreaded diseases affecting the vastness of society. Unfortunately, still some people die especially when cancer is not diagnosed and thus caught early enough. On the other hand, using available chemo- or radiotherapy may result in serious side effects. Therefore, cancer-specific medications seem to be the most desired and safe therapy. Knowing that some cancers are characterized by overexpression of specific receptors on the cell surface, target-mediated drugs could serve as a unique and effective form of therapy. In line with this, recently dopaminergic receptors were presented important in cancer therapy as several dopaminergic ligands revealed their efficacy in tumor growth reduction as well as in apoptosis mediation. Unfortunately, the indication of whether DA receptor agonists or antagonists are the best choices in cancer treatment is quite difficult, since both of them may exert either pro- or anticancer effects. In this review, we analyze the therapeutic efficacy of compounds, both of exogenous and endogenous origin, targeting dopaminergic receptor-expressing cancers.

Treatment of cancer with antipsychotic medications: Pushing the boundaries of schizophrenia and cancer

Over a century ago, the phenothiazine dye, methylene blue, was discovered to have both antipsychotic and anti-cancer effects. In the 20th-century, the first phenothiazine antipsychotic, chlorpromazine, was found to inhibit cancer. During the years of elucidating the pharmacology of the phenothiazines, reserpine, an antipsychotic with a long historical background, was likewise discovered to have anti-cancer properties. Research on the effects of antipsychotics on cancer continued slowly until the 21st century when efforts to repurpose antipsychotics for cancer treatment accelerated. This review examines the history of these developments, and identifies which antipsychotics might treat cancer, and which cancers might be treated by antipsychotics. The review also describes the molecular mechanisms through which antipsychotics may inhibit cancer. Although the overlap of molecular pathways between schizophrenia and cancer have been known or suspected for many years, no comprehensive review of the subject has appeared in the psychiatric literature to assess the significance of these similarities. This review fills that gap and discusses what, if any, significance the similarities have regarding the etiology of schizophrenia.

Glioblastoma: Current Status, Emerging Targets, and Recent Advances

Glioblastoma (GBM) is a highly malignant brain tumor characterized by a heterogeneous population of genetically unstable and highly infiltrative cells that are resistant to chemotherapy. Although substantial efforts have been invested in the field of anti-GBM drug discovery in the past decade, success has primarily been confined to the preclinical level, and clinical studies have often been hampered due to efficacy-, selectivity-, or physicochemical property-related issues. Thus, expansion of the list of molecular targets coupled with a pragmatic design of new small-molecule inhibitors with central nervous system (CNS)-penetrating ability is required to steer the wheels of anti-GBM drug discovery endeavors. This Perspective presents various aspects of drug discovery (challenges in GBM drug discovery and delivery, therapeutic targets, and agents under clinical investigation). The comprehensively covered sections include the recent medicinal chemistry campaigns embarked upon to validate the potential of numerous enzymes/proteins/receptors as therapeutic targets in GBM.

Injectable Hydrogels of Stimuli-Responsive Elastin and Calmodulin-Based Triblock Copolypeptides for Controlled Drug Release

A variety of block copolypeptides with stimuli responsiveness have been of growing interest for dynamic self-assembly. Here, multistimuli-responsive triblock copolypeptides composed of thermosensitive elastin-based polypeptides (EBP) and ligand-responsive calmodulin (CalM) were genetically engineered, over-expressed, and nonchromatographically purified by inverse transition cycling. Diluted EBP-CalM-EBP (ECE) triblock copolypeptides under physiological conditions self-assembled into vesicles at the nanoscale by temperature-triggered aggregation of the EBP block with lower critical solution temperature behaviors. Furthermore, concentrated ECE triblock copolypeptides under identical conditions exhibited thermally induced gelation, resulting in physically crosslinked hydrogels. They showed controlled rheological and mechanical properties depending on the conformational change of the CalM middle block induced by binding either Ca²⁺ or Ca²⁺ and trifluoperazines (TFPs) as ligands. In addition, both Ca²⁺-free and Ca²⁺-bound ECE triblock copolypeptide hydrogels exhibited biocompatibility, while those bound to both Ca²⁺ and TFPs showed severe cytotoxicity because of controlled TFP release of the CalM blocks. The ECE triblock hydrogels with stimuli responsiveness would be useful as injectable drug delivery depots for biomedical applications.

Chlorpromazine induces cytotoxic autophagy in glioblastoma cells via endoplasmic reticulum stress and unfolded protein response

BACKGROUND

Glioblastoma (GBM; grade IV glioma) is characterized by a very short overall survival time and extremely low 5-year survival rates. We intend to promote experimental and clinical research on rationale and scientifically driven drug repurposing. This may represent a safe and often inexpensive way to propose novel pharmacological approaches to GBM. Our precedent work describes the role of chlorpromazine (CPZ) in hindering malignant features of GBM. Here, we investigate in greater detail the molecular mechanisms at the basis of the effect of CPZ on GBM cells.

METHODS

We employed proteomics platforms, i.e., activity-based protein profiling plus mass spectrometry, to identify potential cellular targets of the drug. Then, by means of established molecular and cellular biology techniques, we assessed the effects of this drug on GBM cell metabolic and survival pathways.

RESULTS

The experimental output indicated as putative targets of CPZ several of factors implicated in endoplasmic reticulum (ER) stress, with consequent unfolded protein response (UPR). Such a perturbation culminated in a noticeable reactive oxygen species generation and intense autophagic response that resulted in cytotoxic and abortive effects for six GBM cell lines, three of which growing as neurospheres, while it appeared cytoprotective for the RPE-1 human non-cancer neuro-ectodermal cell line.

CONCLUSIONS

This discrepancy could be central in explaining the lethal effects of the drug on GBM cells and the relatively scarce cytotoxicity toward normal tissues attributed to this compound. The data presented here offer support to the multicenter phase II clinical trial we have undertaken, which consists of the addition of CPZ to first-line treatment of GBM patients carrying a hypo- or un-methylated MGMT gene, i.e. those characterized by intrinsic resistance to temozolomide.

Antidepressants and Antipsychotic Agents as Repurposable Oncological Drug Candidates

Drug repurposing, also known as drug repositioning/reprofiling, is a relatively new strategy for the identification of alternative uses of well-known therapeutics that are outside the scope of their original medical indications. Such an approach might entail a number of advantages compared to standard de novo drug development, including less time needed to introduce the drug to the market, and lower costs. The group of compounds that could be considered as promising candidates for repurposing in oncology include the central nervous system drugs, especially selected antidepressant and antipsychotic agents. In this article, we provide an overview of some antidepressants (citalopram, fluoxetine, paroxetine, sertraline) and antipsychotics (chlorpromazine, pimozide, thioridazine, trifluoperazine) that have the potential to be repurposed as novel chemotherapeutics in cancer treatment, as they have been found to exhibit preventive and/or therapeutic action in cancer patients. Nevertheless, although drug repurposing seems to be an attractive strategy to search for oncological drugs, we would like to clearly indicate that it should not replace the search for new lead structures, but only complement de novo drug development.

Four Novel Prognostic Genes Related to Prostate Cancer Identified Using Co-expression Structure Network Analysis

Prostate cancer (PCa) is one of the most common malignancies for males, but very little is known about its pathogenesis. This study aimed to identify novel biomarkers associated with PCa prognosis and elucidate the underlying molecular mechanism. First, The Cancer Genome Atlas (TCGA) RNA-sequencing data were utilized to identify differentially expressed genes (DEGs) between tumor and normal samples. The DEGs were then applied to construct a co-expression and mined using structure network analysis. The magenta module that was highly related to the Gleason score (r = 0.46, p = 3e-26) and tumor stage (r = 0.38, p = 2e-17) was screened. Subsequently, all genes of the magenta module underwent function annotation. From the key module, CCNA2, CKAP2L, NCAPG, and NUSAP1 were chosen as the four candidate genes. Finally, internal (TCGA) and external data sets (GSE32571, GSE70770, and GSE141551) were combined to validate and predict the value of real hub genes. The results show that the above genes are up-regulated in PCa samples, and higher expression levels show significant association with higher Gleason scores and tumor T stage. Moreover, receiver operating characteristic curve and survival analysis validate the excellent value of hub genes in PCa progression and prognosis. In addition, the protein levels of these four genes also remain higher in tumor tissues when compared with normal tissues. Gene set enrichment analysis and gene set variation analysis for a single gene reveal the close relation with cell proliferation. Meanwhile, 11 small molecular drugs that have the potential to treat PCa were also screened. In conclusion, our research identified four potential prognostic genes and several candidate molecular drugs for treating PCa.

Anticancer Properties of the Antipsychotic Drug Chlorpromazine and Its Synergism With Temozolomide in Restraining Human Glioblastoma Proliferation In Vitro

The extremely poor prognosis of patients affected by glioblastoma (GBM, grade IV glioma) prompts the search for new and more effective therapies. In this regard, drug repurposing or repositioning can represent a safe, swift, and inexpensive way to bring novel pharmacological approaches from bench to bedside. Chlorpromazine, a medication used since six decades for the therapy of psychiatric disorders, shows in vitro several features that make it eligible for repositioning in cancer therapy. Using six GBM cell lines, three of which growing as patient-derived neurospheres and displaying stem-like properties, we found that chlorpromazine was able to inhibit viability in an apoptosis-independent way, induce hyperdiploidy, reduce cloning efficiency as well as neurosphere formation and downregulate the expression of stemness genes in all these cell lines. Notably, chlorpromazine synergized with temozolomide, the first-line therapeutic in GBM patients, in hindering GBM cell viability, and both drugs strongly cooperated in reducing cloning efficiency and inducing cell death in vitro for all the GBM cell lines assayed. These results prompted us to start a Phase II clinical trial on GBM patients (EudraCT # 2019-001988-75; ClinicalTrials.gov Identifier: NCT04224441) by adding chlorpromazine to temozolomide in the adjuvant phase of the standard first-line therapeutic protocol.

Dopamine Receptor Antagonists, Radiation, and Cholesterol Biosynthesis in Mouse Models of Glioblastoma

BACKGROUND

Glioblastoma is the deadliest brain tumor in adults, and the standard of care consists of surgery followed by radiation and treatment with temozolomide. Overall survival times for patients suffering from glioblastoma are unacceptably low indicating an unmet need for novel treatment options.

METHODS

Using patient-derived HK-157, HK-308, HK-374, and HK-382 glioblastoma lines, the GL261 orthotopic mouse models of glioblastoma, and HK-374 patient-derived orthotopic xenografts, we tested the effect of radiation and the dopamine receptor antagonist quetiapine on glioblastoma self-renewal in vitro and survival in vivo. A possible resistance mechanism was investigated using RNA-sequencing. The blood-brain-barrier-penetrating statin atorvastatin was used to overcome this resistance mechanism. All statistical tests were 2-sided.

RESULTS

Treatment of glioma cells with the dopamine receptor antagonist quetiapine reduced glioma cell self-renewal in vitro, and combined treatment of mice with quetiapine and radiation prolonged the survival of glioma-bearing mice. The combined treatment induced the expression of genes involved in cholesterol biosynthesis. This rendered GL261 and HK-374 orthotopic tumors vulnerable to simultaneous treatment with atorvastatin and further statistically significantly prolonged the survival of C57BL/6 (n = 10 to 16 mice per group; median survival not reached; log-rank test, P < .001) and NOD Scid gamma mice (n = 8 to 21 mice per group; hazard ratio = 3.96, 95% confidence interval = 0.29 to 12.40; log-rank test, P < .001), respectively.

CONCLUSIONS

Our results indicate promising therapeutic efficacy with the triple combination of quetiapine, atorvastatin, and radiation treatment against glioblastoma without increasing the toxicity of radiation. With both drugs readily available for clinical use, our study could be rapidly translated into a clinical trial.

Repurposing FDA approved drugs inhibiting mitochondrial function for targeting glioma-stem like cells

Glioblastoma Multiforme (GBM) tumors contain a small population of glioma stem-like cells (GSCs) among the various differentiated GBM cells (d-GCs). GSCs drive tumor recurrence, and resistance to Temozolomide (TMZ), the standard of care (SoC) for GBM chemotherapy. In order to investigate a potential link between GSC specific mitochondria function and SoC resistance, two patient-derived GSC lines were evaluated for differences in their mitochondrial metabolism. In both the lines, GSCs had significantly lower mitochondrial -content, and -function compared to d-GCs. In vitro, the standard mitochondrial-specific inhibitors oligomycin A, antimycin A, and rotenone selectively inhibited GSC proliferation to a greater extent than d-GCs and human primary astrocytes. These findings indicate that mitochondrial inhibition can be a potential GSC-targeted therapeutic strategy in GBM with minimal off-target toxicity. Mechanistically the standard mitochondrial inhibitors elicit their GSC-selective cytotoxic effects through the induction of apoptosis or autophagy pathways. We tested for GSC proliferation in the presence of 3 safe FDA-approved drugs--trifluoperazine, mitoxantrone, and pyrvinium pamoate, all of which are also known mitochondrial-targeting agents. The SoC GBM therapeutic TMZ did not trigger cytotoxicity in glioma stem cells, even at 100 μM concentration. By contrast, trifluoperazine, mitoxantrone, and pyrvinium pamoate exerted antiproliferative effects in GSCs about 30-50 fold more effectively than temozolomide. Thus, we hereby demonstrate that FDA-approved mitochondrial inhibitors induce GSC-selective cytotoxicity, and targeting mitochondrial function could present a potential therapeutic option for GBM treatment.

A comprehensive review in improving delivery of small-molecule chemotherapeutic agents overcoming the blood-brain/brain tumor barriers for glioblastoma treatment

Glioblastoma (GBM) is the most common and lethal primary brain tumor which is highly resistant to conventional radiotherapy and chemotherapy, and cannot be effectively controlled by surgical resection. Due to inevitable recurrence of GBM, it remains essentially incurable with a median overall survival of less than 18 months after diagnosis. A great challenge in current therapies lies in the abrogated delivery of most of the chemotherapeutic agents to the tumor location in the presence of blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB). These protective barriers serve as a selectively permeable hurdle reducing the efficacy of anti-tumor drugs in GBM therapy. This work systematically gives a comprehensive review on: (i) the characteristics of the BBB and the BBTB, (ii) the influence of BBB/BBTB on drug delivery and the screening strategy of small-molecule chemotherapeutic agents with promising BBB/BBTB-permeable potential, (iii) the strategies to overcome the BBB/BBTB as well as the techniques which can lead to transient BBB/BBTB opening or disruption allowing for improving BBB/BBTB-penetration of drugs. It is hoped that this review provide practical guidance for the future development of small BBB/BBTB-permeable agents against GBM as well as approaches enhancing drug delivery across the BBB/BBTB to GBM.

Receptor tyrosine kinase targeting in glioblastoma: performance, limitations and future approaches

From all central nervous system tumors, gliomas are the most common. Nowadays, researchers are looking for more efficient treatments for these tumors, as well as ways for early diagnosis. Receptor tyrosine kinases (RTKs) are major targets for oncology and the development of small-molecule RTK inhibitors has been proven successful in cancer treatment. Mutations or aberrant activation of the RTKs and their intracellular signaling pathways are linked to several malignant diseases, including glioblastoma. The progress in the understanding of malignant glioma evolution has led to RTK targeted therapies with high capacity to improve the therapeutic response while reducing toxicity. In this review, we present the most important RTKs (i.e. EGFR, IGFR, PDGFR and VEGFR) currently used for developing cancer therapeutics together with the potential of RTK-related drugs in glioblastoma treatment. Also, we focus on some therapeutic agents that are currently at different stages of research or even in clinical phases and proved to be suitable as re-purposing candidates for glioblastoma treatment.

Repurposing chlorpromazine in the treatment of glioblastoma multiforme: analysis of literature and forthcoming steps

Background

Glioblastoma multiforme is a CNS cancer characterized by diffuse infiltrative growth, aggressive clinical behavior and very poor prognosis. The state-of-art clinical approach to this disease consists of surgical resection followed by radiotherapy plus concurrent and adjuvant chemotherapy with temozolomide. Tumor recurrence occurs in virtually all cases, therefore, despite any treatment, the median survival is very low (14.6 months), which makes the approach to these patients a challenging clinical issue.

Main body

The escalating costs and times required for new medications to reach the bedside make repurposing or repositioning of old drugs, when scientific bases allow their use in other pathologies, an appealing strategy. Here, we analyze a number of literature data concerning the antipsychotic chlorpromazine, the founder of the phenothiazines class of drugs, a medication widely used in the clinics for approximately 60 years. The drug exerts its effects on psychiatric patients by interfering with the dopamine receptor D₂, although more recent pharmacodynamics studies ascribe chlorpromazine a series of biological effects on cancer cells, all converging in hindering also glioblastoma survival capabilities.

Short conclusions

On these bases, and assisted by the information on the well-established chlorpromazine toxicity and dosage in humans, we designed a Phase II clinical trial involving the combination of chlorpromazine with the standard treatment, temozolomide, in the adjuvant phase of the therapeutic protocol. Patients displaying hypo-methylation of the MGMT gene, and thus intrinsically resistant to temozolomide, will be enrolled. The endpoints of this study are the analysis of toxicity and clinical activity, as evaluated in terms of Progression-Free Survival, of the association of chlorpromazine with the first-line treatment for this very serious form of cancer.

Identification of 9 key genes and small molecule drugs in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a heterogeneous tumor that the underlying molecular mechanisms are largely unclear. This study aimed to elucidate the key candidate genes and pathways in ccRCC by integrated bioinformatics analysis. 1387 differentially expressed genes were identified based on three expression profile datasets, including 673 upregulated genes and 714 downregulated genes. Then we used weighted correlation network analysis to identify 6 modules associated with pathological stage and grade, blue module was the most relevant module. GO and KEGG pathway analyses showed that genes in blue module were enriched in cell cycle and metabolic related pathways. Further, 25 hub genes in blue module were identified as hub genes. Based on GEPIA database, 9 genes were associated with progression and prognosis of ccRCC patients, including PTTG1, RRM2, TOP2A, UHRF1, CEP55, BIRC5, UBE2C, FOXM1 and CDC20. Then multivariate Cox regression showed that the risk score base on 9 key genes signature was a clinically independent prognostic factor for ccRCC patients. Moreover, we screened out several new small molecule drugs that have the potential to treat ccRCC. Few of them were identified as biomarkers in ccRCC. In conclusion, our research identified 9 potential prognostic genes and several candidate small molecule drugs for ccRCC treatment.

Ligand-based design identifies a potent NUPR1 inhibitor exerting anticancer activity via necroptosis

Intrinsically disordered proteins (IDPs) are emerging as attractive drug targets by virtue of their prevalence in various diseases including cancer. Drug development targeting IDPs is challenging because they have dynamical structure features and conventional drug design is not applicable. NUPR1 is an IDP playing an important role in pancreatic cancer. We previously reported that Trifluoperazine (TFP), an antipsychotic agent, was capable of binding to NUPR1 and inhibiting tumors growth. Unfortunately, TFP showed strong central nervous system side-effects. In this work, we undertook a multidisciplinary approach to optimize TFP, based on the synergy of computer modeling, chemical synthesis, and a variety of biophysical, biochemical and biological evaluations. A family of TFP-derived compounds was produced and the most active one, named ZZW-115, showed a dose-dependent tumor regression with no neurological effects and induced cell death mainly by necroptosis. This study opens a new perspective for drug development against IDPs, demonstrating the possibility of successful ligand-based drug design for such challenging targets.

Recent advances in the discovery of small molecules targeting glioblastoma

Glioblastoma (GBM) is one of the most common central nervous system cancers. It is characterized as a fast-growing tumor that arises from multiple cell types with neural stem-cell-like properties. Additionally, GBM tumors are highly invasive, which is attributed to the presence of glioblastoma stem cells that makes surgery ineffective in most cases. Currently, temozolomide is the unique chemotherapy option approved by the U.S. Food and Drug Administration for GBM treatment. This review analyzes the emergence and development of new synthetic small molecules discovered as promising anti-glioblastoma agents. A number of compounds were described herein and grouped according to the main chemical class used in the drug discovery process. Importantly, we focused only on synthetic compounds published in the last 10 years, thus excluding natural products. Furthermore, we included in this review only those most biologically active compounds with proven in vitro and/or in vivo efficacy.

Antipsychotic dopamine receptor antagonists, cancer, and cancer stem cells

Cancer is one of the deadliest diseases in the world. Despite extensive studies, treating metastatic cancers remains challenging. Years of research have linked a rare set of cells known as cancer stem cells (CSCs) to drug resistance, leading to the suggestion that eradication of CSCs might be an effective therapeutic strategy. However, few drug candidates are active against CSCs. New drug discovery is often a lengthy process. Drug screening has been advantageous in identifying drug candidates. Current understanding of cancer biology has revealed various clues to target cancer from different points of view. Many studies have found dopamine receptors (DRs) in various cancers. Therefore, DR antagonists have attracted a lot of attention in cancer research. Recently, a group of antipsychotic DR antagonists has been demonstrated to possess remarkable abilities to restrain and sensitize CSCs to existing chemotherapeutics by a process called differentiation approach. In this review, we will describe current aspects of CSC-targeting therapeutics, antipsychotic DR antagonists, and their extraordinary abilities to fight cancer.

Drug Repositioning in Glioblastoma: A Pathway Perspective

Glioblastoma multiforme (GBM) is the most malignant primary adult brain tumor. The current standard of care is surgical resection, radiation, and chemotherapy treatment, which extends life in most cases. Unfortunately, tumor recurrence is nearly universal and patients with recurrent glioblastoma typically survive <1 year. Therefore, new therapies and therapeutic combinations need to be developed that can be quickly approved for use in patients. However, in order to gain approval, therapies need to be safe as well as effective. One possible means of attaining rapid approval is repurposing FDA approved compounds for GBM therapy. However, candidate compounds must be able to penetrate the blood-brain barrier (BBB) and therefore a selection process has to be implemented to identify such compounds that can eliminate GBM tumor expansion. We review here psychiatric and non-psychiatric compounds that may be effective in GBM, as well as potential drugs targeting cell death pathways. We also discuss the potential of data-driven computational approaches to identify compounds that induce cell death in GBM cells, enabled by large reference databases such as the Library of Integrated Network Cell Signatures (LINCS). Finally, we argue that identifying pathways dysregulated in GBM in a patient specific manner is essential for effective repurposing in GBM and other gliomas.