scholarly journals Combining CRISPR/Cas9 mutagenesis and a small-molecule inhibitor to probe the function of MELK in cancer

2017 ◽  
Author(s):  
Christopher J. Giuliano ◽  
Ann Lin ◽  
Joan C. Smith ◽  
Ann C. Palladino ◽  
Jason M. Sheltzer
Keyword(s):  
Drug Targets ◽  
Leucine Zipper ◽  
Chemotherapy Resistance ◽  
Cancer Drug ◽  
Cell Renewal ◽  
Multiple Cancer ◽  
Clinical Prognosis ◽  
Phenotype Analysis

AbstractThe Maternal Embryonic Leucine Zipper Kinase (MELK) has been identified as a promising therapeutic target in multiple cancer types. MELK over-expression is associated with aggressive disease, and MELK has been implicated in numerous cancer-related processes, including chemotherapy resistance, stem cell renewal, and tumor growth. On the basis of these findings, a MELK inhibitor is currently being tested in several clinical trials. Here, we report that cancer cell lines harboring CRISPR/Cas9-induced null mutations in MELK exhibit wild-type growthin vitro, under environmental stress, in the presence of multiple chemotherapy agents, andin vivo. By combining our MELK-knockout clones with a recently-described, highly-specific MELK inhibitor, we further demonstrate that the acute inhibition of MELK results in no specific anti-proliferative phenotype. Analysis of gene expression data from cohorts of cancer patients identifies MELK expression as a correlate of tumor mitotic activity, explaining its association with poor clinical prognosis. In total, our results demonstrate the power of CRISPR/Cas9-based genetic approaches to investigate cancer drug targets, and call into question the rationale for treating patients with anti-MELK monotherapies.

scholarly journals MELK expression correlates with tumor mitotic activity but is not required for cancer growth

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Christopher J Giuliano ◽  
Ann Lin ◽  
Joan C Smith ◽  
Ann C Palladino ◽  
Jason M Sheltzer
Keyword(s):  
Mitotic Activity ◽  
Cancer Drug ◽  
Breast Cancer Cell Lines ◽  
Cell Renewal ◽  
Wild Type ◽  
Multiple Cancer ◽  
Clinical Prognosis ◽  
Cancer Types

The Maternal Embryonic Leucine Zipper Kinase (MELK) has been identified as a promising therapeutic target in multiple cancer types. MELK over-expression is associated with aggressive disease, and MELK has been implicated in numerous cancer-related processes, including chemotherapy resistance, stem cell renewal, and tumor growth. Previously, we established that triple-negative breast cancer cell lines harboring CRISPR/Cas9-induced null mutations in MELK proliferate at wild-type levels in vitro (<xref ref-type="bibr" rid="bib34">Lin et al., 2017</xref>). Here, we generate several additional knockout clones of MELK and demonstrate that across cancer types, cells lacking MELK exhibit wild-type growth in vitro, under environmental stress, in the presence of cytotoxic chemotherapies, and in vivo. By combining our MELK-knockout clones with a recently described, highly specific MELK inhibitor, we further demonstrate that the acute inhibition of MELK results in no specific anti-proliferative phenotype. Analysis of gene expression data from cohorts of cancer patients identifies MELK expression as a correlate of tumor mitotic activity, explaining its association with poor clinical prognosis. In total, our results demonstrate the power of CRISPR/Cas9-based genetic approaches to investigate cancer drug targets, and call into question the rationale for treating patients with anti-MELK monotherapies.

scholarly journals Development of A Novel Highly Selective TLR8 Agonist for Cancer Immunotherapy

2020 ◽  
Author(s):  
Yuxun Wang ◽  
Heping Yang ◽  
Huanping Li ◽  
Shuda Zhao ◽  
Yikun Zeng ◽  
...  
Keyword(s):  
Immune Responses ◽  
Drug Targets ◽  
Ex Vivo ◽  
Single Agent ◽  
Cancer Drug ◽  
Phase I Clinical Trials ◽  
Tlr Agonists ◽  
Favorable Safety

ABSTRACTToll-like receptors (TLRs) are a family of proteins that recognize pathogen associated molecular patterns (PAMPs). Their primary function is to activate innate immune responses while also involved in facilitating adaptive immune responses. Different TLRs exert distinct functions by activating varied immune cascades. Several TLRs are being pursued as cancer drug targets. We discovered a novel, highly potent and selective small molecule TLR8 agonist DN052. DN052 exhibited strong in vitro cellular activity with EC50 at 6.7 nM and was highly selective for TLR8 over other TLRs including TLR4, 7 and 9. The selectivity profile distinguished DN052 from all other TLR agonists currently in clinical development. DN052 displayed excellent in vitro ADMET and in vivo PK profiles. DN052 potently inhibited tumor growth as a single agent. Moreover, combination of DN052 with the immune checkpoint inhibitor, selected targeted therapeutics or chemotherapeutic drugs further enhanced efficacy of single agents. Mechanistically, treatment with DN052 resulted in strong induction of pro-inflammatory cytokines in ex vivo human PBMC assay and in vivo monkey study. GLP toxicity studies in rats and monkeys demonstrated favorable safety profile. This led to the advancement of DN052 into phase I clinical trials.

scholarly journals Development of a novel TLR8 agonist for cancer immunotherapy

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Yuxun Wang ◽  
Heping Yang ◽  
Huanping Li ◽  
Shuda Zhao ◽  
Yikun Zeng ◽  
...  
Keyword(s):  
Immune Responses ◽  
Drug Targets ◽  
Ex Vivo ◽  
Phase 1 ◽  
Single Agent ◽  
Cancer Drug ◽  
Favorable Safety ◽  
Molecular Patterns

Abstract Toll-like receptors (TLRs) are a family of proteins that recognize pathogen associated molecular patterns (PAMPs). Their primary function is to activate innate immune responses while also involved in facilitating adaptive immune responses. Different TLRs exert distinct functions by activating varied immune cascades. Several TLRs are being pursued as cancer drug targets. We discovered a novel, highly potent and selective small molecule TLR8 agonist DN052. DN052 exhibited strong in vitro cellular activity with EC50 at 6.7 nM and was highly selective for TLR8 over other TLRs including TLR4, 7 and 9. DN052 displayed excellent in vitro ADMET and in vivo PK profiles. DN052 potently inhibited tumor growth as a single agent. Moreover, combination of DN052 with the immune checkpoint inhibitor, selected targeted therapeutics or chemotherapeutic drugs further enhanced efficacy of single agents. Mechanistically, treatment with DN052 resulted in strong induction of pro-inflammatory cytokines in ex vivo human PBMC assay and in vivo monkey study. GLP toxicity studies in rats and monkeys demonstrated favorable safety profile. This led to the advancement of DN052 into phase 1 clinical trials.

scholarly journals Current Status of the Use of Multifunctional Enzymes as Anti-Cancer Drug Targets

Pharmaceutics ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 10
Author(s):  
Carla S. S. Teixeira ◽  
Sérgio F. Sousa
Keyword(s):  
Posttranslational Modifications ◽  
Drug Targets ◽  
Current Status ◽  
Cancer Drug ◽  
Cancer Cell Growth ◽  
Anti Cancer ◽  
Multifunctional Enzymes ◽  
Potential Inhibitors

Fighting cancer is one of the major challenges of the 21st century. Among recently proposed treatments, molecular-targeted therapies are attracting particular attention. The potential targets of such therapies include a group of enzymes that possess the capability to catalyze at least two different reactions, so-called multifunctional enzymes. The features of such enzymes can be used to good advantage in the development of potent selective inhibitors. This review discusses the potential of multifunctional enzymes as anti-cancer drug targets along with the current status of research into four enzymes which by their inhibition have already demonstrated promising anti-cancer effects in vivo, in vitro, or both. These are PFK-2/FBPase-2 (involved in glucose homeostasis), ATIC (involved in purine biosynthesis), LTA4H (involved in the inflammation process) and Jmjd6 (involved in histone and non-histone posttranslational modifications). Currently, only LTA4H and PFK-2/FBPase-2 have inhibitors in active clinical development. However, there are several studies proposing potential inhibitors targeting these four enzymes that, when used alone or in association with other drugs, may provide new alternatives for preventing cancer cell growth and proliferation and increasing the life expectancy of patients.

scholarly journals Cutting down the time to identify challenging tumor therapeutic targets and drug combinations using synthetic lethal approaches

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 308 ◽  
Author(s):  
John S. Lazo
Keyword(s):  
Drug Targets ◽  
Gene Mutations ◽  
Cancer Therapeutics ◽  
Drug Combinations ◽  
Cancer Drug ◽  
Loss Of Function ◽  
Synthetic Lethal ◽  
Optimal Drug

Cancer drug discoverers and developers are blessed and cursed with a plethora of drug targets in the tumor cells themselves and the surrounding stromal elements. This bounty of targets has, at least in part, inspired the rapid increase in the number of clinically available small-molecule, biological, and cellular therapies for solid and hematological malignancies. Among the most challenging questions in cancer therapeutics, especially for small molecules, is how to approach loss-of-function gene mutations or deletions that encode tumor suppressors. A second mounting question is what are the optimal drug combinations. This article will briefly review the recent advances in exploiting in vitro and in vivo synthetic lethal screens to expose cancer pharmacological targets with the goal of developing new drug combinations.

scholarly journals A technology platform to assess multiple cancer agents simultaneously within a patient’s tumor

2015 ◽  
Vol 7 (284) ◽  
pp. 284ra58-284ra58 ◽  
Author(s):  
Richard A. Klinghoffer ◽  
S. Bahram Bahrami ◽  
Beryl A. Hatton ◽  
Jason P. Frazier ◽  
Alicia Moreno-Gonzalez ◽  
...  
Keyword(s):  
Anticancer Agents ◽  
Drug Exposure ◽  
Fundamental Problem ◽  
Feasibility Studies ◽  
Cancer Drug ◽  
Tumor Resistance ◽  
Multiple Cancer ◽  
Technology Platform

A fundamental problem in cancer drug development is that antitumor efficacy in preclinical cancer models does not translate faithfully to patient outcomes. Much of early cancer drug discovery is performed under in vitro conditions in cell-based models that poorly represent actual malignancies. To address this inconsistency, we have developed a technology platform called CIVO, which enables simultaneous assessment of up to eight drugs or drug combinations within a single solid tumor in vivo. The platform is currently designed for use in animal models of cancer and patients with superficial tumors but can be modified for investigation of deeper-seated malignancies. In xenograft lymphoma models, CIVO microinjection of well-characterized anticancer agents (vincristine, doxorubicin, mafosfamide, and prednisolone) induced spatially defined cellular changes around sites of drug exposure, specific to the known mechanisms of action of each drug. The observed localized responses predicted responses to systemically delivered drugs in animals. In pair-matched lymphoma models, CIVO correctly demonstrated tumor resistance to doxorubicin and vincristine and an unexpected enhanced sensitivity to mafosfamide in multidrug-resistant lymphomas compared with chemotherapy-naïve lymphomas. A CIVO-enabled in vivo screen of 97 approved oncology agents revealed a novel mTOR (mammalian target of rapamycin) pathway inhibitor that exhibits significantly increased tumor-killing activity in the drug-resistant setting compared with chemotherapy-naïve tumors. Finally, feasibility studies to assess the use of CIVO in human and canine patients demonstrated that microinjection of drugs is toxicity-sparing while inducing robust, easily tracked, drug-specific responses in autochthonous tumors, setting the stage for further application of this technology in clinical trials.

scholarly journals NFATc2 enhances tumor-initiating phenotypes through the NFATc2/SOX2/ALDH axis in lung adenocarcinoma

2017 ◽  
Author(s):  
Zhi-Jie Xiao ◽  
Jing Liu ◽  
Si-Qi Wang ◽  
Yun Zhu ◽  
Xu-Yuan Gao ◽  
...  
Keyword(s):  
Term Treatment ◽  
Cancer Drug ◽  
Molecular Heterogeneity ◽  
Cell Renewal ◽  
Tumor Initiating Cells ◽  
Lung Cancers ◽  
Oxidative Stresses ◽  
Long Term Treatment

AbstractCancers display intratumoral genetic and molecular heterogeneity with tumor initiating cells (TIC) showing enhanced tumor phenotypes. In this study, we show the calcium pathway transcription factor NFATc2 is a novel regulator of lung TIC through the NFATc2/SOX2/ALDH1A1 regulatory axis.In vitroandin vivocancer cell modeling demonstrated supportive evidences including cell renewal, tumorigenicity at limiting dose, cell motility, resistance to cytotoxic chemotherapy and EGFR targeted therapy. In human lung cancers, high NFATc2 expression predicts poor tumor differentiation, adverse recurrence-free and overall patient survivals. Mechanistic investigations identified NFATc2 response elements in the SOX2 3’ enhancer region, and NFATc2/SOX2 coupling upregulates ALDH1A1 by binding to its 5’ enhancer. Through this axis, oxidative stresses and reactive oxygen species induced by cancer drug treatment are attenuated, accounting for a mutation-independent mechanism of drug resistance. Targeting this axis provides a novel approach for the long term treatment of lung cancer through TIC elimination.

Current Status and Future Perspective for Research on Medicinal Plants with Anticancerous Activity and Minimum Cytotoxic Value

2019 ◽  
Vol 20 (12) ◽  
pp. 1227-1243
Author(s):  
Hina Qamar ◽  
Sumbul Rehman ◽  
D.K. Chauhan
Keyword(s):  
Side Effects ◽  
Medicinal Plants ◽  
Anticancer Agents ◽  
Drug Targets ◽  
Psidium Guajava ◽  
Current Status ◽  
Future Perspective ◽  
Wide Range

Cancer is the second leading cause of morbidity and mortality worldwide. Although chemotherapy and radiotherapy enhance the survival rate of cancerous patients but they have several acute toxic effects. Therefore, there is a need to search for new anticancer agents having better efficacy and lesser side effects. In this regard, herbal treatment is found to be a safe method for treating and preventing cancer. Here, an attempt has been made to screen some less explored medicinal plants like Ammania baccifera, Asclepias curassavica, Azadarichta indica, Butea monosperma, Croton tiglium, Hedera nepalensis, Jatropha curcas, Momordica charantia, Moringa oleifera, Psidium guajava, etc. having potent anticancer activity with minimum cytotoxic value (IC50 >3μM) and lesser or negligible toxicity. They are rich in active phytochemicals with a wide range of drug targets. In this study, these medicinal plants were evaluated for dose-dependent cytotoxicological studies via in vitro MTT assay and in vivo tumor models along with some more plants which are reported to have IC50 value in the range of 0.019-0.528 mg/ml. The findings indicate that these plants inhibit tumor growth by their antiproliferative, pro-apoptotic, anti-metastatic and anti-angiogenic molecular targets. They are widely used because of their easy availability, affordable price and having no or sometimes minimal side effects. This review provides a baseline for the discovery of anticancer drugs from medicinal plants having minimum cytotoxic value with minimal side effects and establishment of their analogues for the welfare of mankind.

Polyamines and Related Nitrogen Compounds in the Chemotherapy of Neglected Diseases Caused by Kinetoplastids

2018 ◽  
Vol 18 (5) ◽  
pp. 321-368 ◽  
Author(s):  
Juan A. Bisceglia ◽  
Maria C. Mollo ◽  
Nadia Gruber ◽  
Liliana R. Orelli
Keyword(s):  
Drug Targets ◽  
Redox Homeostasis ◽  
Cost Effective ◽  
Structural Features ◽  
Mammalian Host ◽  
Neglected Diseases ◽  
Nitrogen Compounds ◽  
Chemical Structures

Neglected diseases due to the parasitic protozoa Leishmania and Trypanosoma (kinetoplastids) affect millions of people worldwide, and the lack of suitable treatments has promoted an ongoing drug discovery effort to identify novel nontoxic and cost-effective chemotherapies. Polyamines are ubiquitous small organic molecules that play key roles in kinetoplastid parasites metabolism, redox homeostasis and in the normal progression of cell cycles, which differ from those found in the mammalian host. These features make polyamines attractive in terms of antiparasitic drug development. The present work provides a comprehensive insight on the use of polyamine derivatives and related nitrogen compounds in the chemotherapy of kinetoplastid diseases. The amount of literature on this subject is considerable, and a classification considering drug targets and chemical structures were made. Polyamines, aminoalcohols and basic heterocycles designed to target the relevant parasitic enzyme trypanothione reductase are discussed in the first section, followed by compounds directed to less common targets, like parasite SOD and the aminopurine P2 transporter. Finally, the third section comprises nitrogen compounds structurally derived from antimalaric agents. References on the chemical synthesis of the selected compounds are reported together with their in vivo and/or in vitro IC50 values, and structureactivity relationships within each group are analyzed. Some favourable structural features were identified from the SAR analyses comprising protonable sites, hydrophobic groups and optimum distances between them. The importance of certain pharmacophoric groups or amino acid residues in the bioactivity of polyamine derived compounds is also discussed.

scholarly journals Pharmacodynamic, pharmacokinetic, and phase 1a study of bisthianostat, a novel histone deacetylase inhibitor, for the treatment of relapsed or refractory multiple myeloma

2021 ◽  
Author(s):  
Yu-bo Zhou ◽  
Yang-ming Zhang ◽  
Hong-hui Huang ◽  
Li-jing Shen ◽  
Xiao-feng Han ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Drug Targets ◽  
Single Agent ◽  
Hdac Inhibitors ◽  
Preclinical Study ◽  
Parp Cleavage ◽  
Rpmi 8226 ◽  
Ongoing Phase

AbstractHDAC inhibitors (HDACis) have been intensively studied for their roles and potential as drug targets in T-cell lymphomas and other hematologic malignancies. Bisthianostat is a novel bisthiazole-based pan-HDACi evolved from natural HDACi largazole. Here, we report the preclinical study of bisthianostat alone and in combination with bortezomib in the treatment of multiple myeloma (MM), as well as preliminary first-in-human findings from an ongoing phase 1a study. Bisthianostat dose dependently induced acetylation of tubulin and H3 and increased PARP cleavage and apoptosis in RPMI-8226 cells. In RPMI-8226 and MM.1S cell xenograft mouse models, oral administration of bisthianostat (50, 75, 100 mg·kg-1·d-1, bid) for 18 days dose dependently inhibited tumor growth. Furthermore, bisthianostat in combination with bortezomib displayed synergistic antitumor effect against RPMI-8226 and MM.1S cell in vitro and in vivo. Preclinical pharmacokinetic study showed bisthianostat was quickly absorbed with moderate oral bioavailability (F% = 16.9%–35.5%). Bisthianostat tended to distribute in blood with Vss value of 0.31 L/kg. This distribution parameter might be beneficial to treat hematologic neoplasms such as MM with few side effects. In an ongoing phase 1a study, bisthianostat treatment was well tolerated and no grade 3/4 nonhematological adverse events (AEs) had occurred together with good pharmacokinetics profiles in eight patients with relapsed or refractory MM (R/R MM). The overall single-agent efficacy was modest, stable disease (SD) was identified in four (50%) patients at the end of first dosing cycle (day 28). These preliminary in-patient results suggest that bisthianostat is a promising HDACi drug with a comparable safety window in R/R MM, supporting for its further phase 1b clinical trial in combination with traditional MM therapies.

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